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  • 1. Andersson, Hanna
    et al.
    Carlsson, anna-Carin
    Nekoueishahraki, Bijan
    Brath, Ulrika
    Erdelyi, Mate
    Solvent effects of nitrogen chemical shifts2015In: Annual Reports on NMR Spectroscopy, ISSN 0066-4103, E-ISSN 2163-6052, Vol. 86, p. 73-210Article, review/survey (Refereed)
  • 2.
    Baltzer, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Polypeptide Conjugate Binders for Protein Recognition2007In: Topics in current chemistry, ISSN 0340-1022, E-ISSN 1436-5049, Vol. 277, p. 89-106Article, review/survey (Refereed)
    Abstract [en]

    A new class of hybrid molecules for protein recognition is presented, where polypeptides are covalently linked to small organic molecules to form polypeptide conjugates that bind proteins with high affinity and selectivity. To illustrate the concept, a binder for human carbonic anhydrase 11 with a dissociation constant of 4 nM is described. The affinity of the polypeptide conjugate arises from cooperativity in binding between a benzenesulfonamide residue, with a dissociation constant of 1.5 mu M, and the polypeptide scaffold with a dissociation constant of < 1 mM. The combination of a ligand with moderate affinity for a target protein with a polypeptide relaxes considerably the need for high affinity on the part of the polypeptide, and thus the need for structural complexity and preorganization. At the same time, the requirement for high affinity on the part of ligand is relaxed. As a consequence, the time for development of robust, high affinity, selective binder is shortened. The chemical approach to protein recognition provides well-defined molecular entities that are conveniently handled, stored and site-specifically functionalized.

  • 3.
    Baltzer, Lars
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    DeGrado, W. F.
    Engineering and design: Expanding the protein world2004In: Editorial overview Current Opinion of Structural Biology, Vol. 14, p. 455-457Article, review/survey (Other (popular scientific, debate etc.))
  • 4.
    Bartoszewicz, Agnieszka
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Marcos, Rocio
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sahoo, Suman
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Inge, A. Ken
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Martín-Matute, Belén
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    A Highly Active Bifunctional Iridium Complex with an Alcohol/Alkoxide-Tethered N-Heterocyclic Carbene for Alkylation of Amines with Alcohols2012In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 18, no 45, p. 14510-14519Article, review/survey (Refereed)
    Abstract [en]

    A series of new iridium(III) complexes containing bidentate N-heterocyclic carbenes (NHC) functionalized with an alcohol or ether group (NHC?OR, R=H, Me) were prepared. The complexes catalyzed the alkylation of anilines with alcohols as latent electrophiles. In particular, biscationic IrIII complexes of the type [Cp*(NHC-OH)Ir(MeCN)]2+2[BF4-] afforded higher-order amine products with very high efficiency; up to >99?% yield using a 1:1 ratio of reactants and 12.5 mol?% of Ir, in short reaction times (216 h) and under base-free conditions. Quantitative yields were also obtained at 50?degrees C, although longer reaction times (4860 h) were needed. A large variety of aromatic amines have been alkylated with primary and secondary alcohols. The reactivity of structurally related iridium(III) complexes was also compared to obtain insights into the mechanism and into the structure of possible catalytic intermediates. The IrIII complexes were stable towards oxygen and moisture, and were characterized by NMR, HRMS, single-crystal X-ray diffraction, and elemental analyses.

  • 5. Bassanini, Ivan
    et al.
    Hult, Karl
    KTH, School of Biotechnology (BIO), Industrial Biotechnology. CNR, Italy.
    Riva, Sergio
    Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers2015In: Beilstein Journal of Organic Chemistry, ISSN 2195-951X, E-ISSN 1860-5397, Vol. 11, p. 1583-1595Article, review/survey (Refereed)
    Abstract [en]

    Dicarboxylic acids and their derivatives (esters and anhydrides) have been used as acylating agents in lipase-catalyzed reactions in organic solvents. The synthetic outcomes have been dimeric or hybrid derivatives of bioactive natural compounds as well as functionalized polyesters.

  • 6.
    Bellissent-Funel, Marie-Claire
    et al.
    CEA Saclay, CNRS, Lab Leon Brillouin, F-91191 Gif Sur Yvette, France..
    Hassanali, Ali
    Abdus Salaam Int Ctr Theoret Phys, Condensed Matter & Stat Phys, I-34151 Trieste, Italy..
    Havenith, Martina
    Ruhr Univ Bochum, Fac Chem & Biochem, Univ Str 150 Bldg NC 7-72, D-44780 Bochum, Germany..
    Henchman, Richard
    Univ Manchester, Manchester Inst Biotechnol, 131 Princess St, Manchester M1 7DN, Lancs, England..
    Pohl, Peter
    Johannes Kepler Univ Linz, Gruberstr 40, A-4020 Linz, Austria..
    Sterpone, Fabio
    Inst Biol Physicochim, Lab Biochim Theor, 13 Rue Pierre & Marie Curie, F-75005 Paris, France..
    van der Spoel, David
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Computational Biology and Bioinformatics.
    Xu, Yao
    Ruhr Univ Bochum, Fac Chem & Biochem, Univ Str 150 Bldg NC 7-72, D-44780 Bochum, Germany..
    Garcia, Angel E.
    Los Alamos Natl Lab, Ctr Non Linear Studies, Los Alamos, NM 87545 USA..
    Water Determines the Structure and Dynamics of Proteins2016In: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 116, no 13, p. 7673-7697Article, review/survey (Refereed)
    Abstract [en]

    Water is an essential participant in the stability, structure, dynamics, and function of proteins and other biomolecules. Thermodynamically, changes in the aqueous environment affect the stability of biomolecules. Structurally, water participates chemically in the catalytic function of proteins and nucleic acids and physically in the collapse of the protein chain during folding through hydrophobic collapse and mediates binding through the hydrogen bond in complex formation. Water is a partner that slaves the dynamics of proteins, and water interaction with proteins affect their dynamics. Here we provide a review of the experimental and computational advances over the past decade in understanding the role of water in the dynamics, structure, and function of proteins. We focus on the combination of X-ray and neutron crystallography, NMR, terahertz spectroscopy, mass spectroscopy, thermodynamics, and computer simulations to reveal how water assist proteins in their function. The recent advances in computer simulations and the enhanced sensitivity of experimental tools promise major advances in the understanding of protein dynamics, and water surely will be a protagonist.

  • 7.
    Blomberg, Margareta R. A.
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Borowski, Tomasz
    Himo, Fahmi
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Liao, Rong-Zhen
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Siegbahn, Per E. M.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Quantum Chemical Studies of Mechanisms for Metalloenzymes2014In: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 114, no 7, p. 3601-3658Article, review/survey (Refereed)
  • 8.
    Cadu, Alban
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Andersson, Pher G.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Development of iridium-catalyzed asymmetric hydrogenation: New catalysts, new substrate scope2012In: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 714, p. 3-11Article, review/survey (Refereed)
    Abstract [en]

    A review. The asym. hydrogenation of olefins is a tremendously powerful tool used to synthesize chiral mols. The field was pioneered using rhodium- and ruthenium- based catalysts; however, catalysts based on both of these metals suffer from limitations, such as the need for directing substituents near or even adjacent to the olefin. Iridium-based catalysts do not suffer from this flaw and can thus hydrogenate a wide variety of olefins, including some tetra substituted ones. It is also possible for iridium-based catalysts to hydrogenate hetero-π bonds such as those found in heteroarom. rings. This review summarizes the contributions made to this field by the authors in the past few years. [on SciFinder(R)]

  • 9. Carlsson, Anna-Carin C
    et al.
    Veiga, Alberte X
    Erdelyi, Mate
    Halogen bonding in solution.2015In: Topics in current chemistry, ISSN 0340-1022, E-ISSN 1436-5049, Vol. 359, p. 49-76Article, review/survey (Refereed)
    Abstract [en]

    Because of its expected applicability for modulation of molecular recognition phenomena in chemistry and biology, halogen bonding has lately attracted rapidly increasing interest. As most of these processes proceed in solution, the understanding of the influence of solvents on the interaction is of utmost importance. In addition, solution studies provide fundamental insights into the nature of halogen bonding, including, for example, the relative importance of charge transfer, dispersion, and electrostatics forces. Herein, a selection of halogen bonding literature is reviewed with the discussion focusing on the solvent effect and the electronic characteristics of halogen bonded complexes. Hence, charged and neutral systems together with two- and three-center bonds are presented in separate sub-sections. Solvent polarity is shown to have a slight stabilizing effect on neutral, two-center halogen bonds while strongly destabilizes charged, two-center complexes. It does not greatly influence the geometry of three-center halogen bonds, even though polar solvents facilitate dissociation of the counter-ion of charged three-center bonds. The charged three-center bonds are strengthened by increased environment polarity. Solvents possessing hydrogen bond donor functionalities efficiently destabilize all types of halogen bonds, primarily because of halogen vs hydrogen bond competition. A purely electrostatic model is insufficient for the description of halogen bonds in polar systems whereas it may give reasonable correlation to experimental data obtained in noninteracting, apolar solvents. Whereas dispersion plays a significant role for neutral, two-center halogen bonds, charged halogen bond complexes possess a significant charge transfer characteristic.

  • 10.
    Cumpstey, Ian
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Synthesis of carbasugar-containing non-glycosidically linked pseudodisaccharides and higher pseudooligosaccharides2009In: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 344, no 17, p. 2285-2310Article, review/survey (Refereed)
  • 11.
    Duan, Lele
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Wang, Lei
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Li, Fusheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Li, Fei
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. State Key Lab of Fine Chemicals, Institute of Artificial Photosynthesis, Dalian University of Technology (DUT), Dalian, China.
    Highly Efficient Bioinspired Molecular Ru Water Oxidation Catalysts with Negatively Charged Backbone Ligands2015In: Accounts of Chemical Research, ISSN 0001-4842, E-ISSN 1520-4898, Vol. 48, no 7, p. 2084-2096Article, review/survey (Refereed)
    Abstract [en]

    The oxygen evolving complex (OEC) of the natural photosynthesis system II (PSII) oxidizes water to produce oxygen and reducing equivalents (protons and electrons). The oxygen released from PSII provides the oxygen source of our atmosphere; the reducing equivalents are used to reduce carbon dioxide to organic products, which support almost all organisms on the Earth planet. The first photosynthetic organisms able to split water were proposed to be cyanobacteria-like ones appearing ca. 2.5 billion years ago. Since then, nature has chosen a sustainable way by using solar energy to develop itself. Inspired by nature, human beings started to mimic the functions of the natural photosynthesis system and proposed the concept of artificial photosynthesis (AP) with the view to creating energy-sustainable societies and reducing the impact on the Earth environments. Water oxidation is a highly energy demanding reaction and essential to produce reducing equivalents for fuel production, and thereby effective water oxidation catalysts (WOCs) are required to catalyze water oxidation and reduce the energy loss. X-ray crystallographic studies on PSII have revealed that the OEC consists of a Mn4CaO5 cluster surrounded by oxygen rich ligands, such as oxyl, oxo, and carboxylate ligands. These negatively charged, oxygen rich ligands strongly stabilize the high valent states of the Mn cluster and play vital roles in effective water oxidation catalysis with low overpotential. This Account describes our endeavors to design effective Ru WOCs with low overpotential, large turnover number, and high turnover frequency by introducing negatively charged ligands, such as carboxylate. Negatively charged ligands stabilized the high valent states of Ru catalysts, as evidenced by the low oxidation potentials. Meanwhile, the oxygen production rates of our Ru catalysts were improved dramatically as well. Thanks to the strong electron donation ability of carboxylate containing ligands, a seven-coordinate Ru-IV species was isolated as a reaction intermediate, shedding light on the reaction mechanisms of Ru-catalyzed water oxidation chemistry. Auxiliary ligands have dramatic effects on the water oxidation catalysis in terms of the reactivity and the reaction mechanism. For instance, Ru-bda (H(2)bda = 2,2'-bipyridine-6,6'-dicarboxylic acid) water oxidation catalysts catalyze Ce-IV-driven water oxidation extremely fast via the radical coupling of two Ru-V=O species, while Ru-pda (H(2)pda = 1,10-phenanthroline-2,9-dicarboxylic acid) water oxidation catalysts catalyze the same reaction slowly via water nucleophilic attack on a Ru-V-O species. With a number of active Ru catalysts in hands, light driven water oxidation was accomplished using catalysts with low catalytic onset potentials. The structures of molecular catalysts could be readily tailored to introduce additional functional groups, which favors the fabrication of state-of-the-art Ru-based water oxidation devices, such as electrochemical water oxidation anodes and photo-electrochemical anodes. The development of efficient water oxidation catalysts has led to a step forward in the sustainable energy system.

  • 12. Erdelyi, Mate
    Application of the Halogen Bond in Protein Systems.2017In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 56, no 22, p. 2759-2761Article, review/survey (Refereed)
  • 13. Erdelyi, Mate
    et al.
    Metrangolo, Pierangelo
    Introduction to the special issue on halogen bonding.2017In: Acta Crystallographica. Section B: Structural Science, Crystal Engineering and Materials, ISSN 2052-5192, E-ISSN 2052-5206, Vol. 73, no Pt 2, article id 135Article, review/survey (Refereed)
  • 14. Hakkert, Sebastiaan
    et al.
    Erdelyi, Mate
    Halogen bond symmetry: the N–X–N bond2015In: Journal of Physical Organic Chemistry, ISSN 0894-3230, E-ISSN 1099-1395, Vol. 28, p. 226-233Article, review/survey (Refereed)
  • 15.
    Joosten, Antoine
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Persson, Andreas K. A.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Millet, Renaud
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Johnson, Magnus T.
    Bäckvall, Jan-E.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Palladium(II)-Catalyzed Oxidative Cyclization of Allylic Tosylcarbamates: Scope, Derivatization, and Mechanistic Aspects2012In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 18, no 47, p. 15151-15157Article, review/survey (Refereed)
    Abstract [en]

    A highly selective oxidative palladium(II)-catalyzed (Wacker-type) cyclization of readily available allylic tosylcarbamates is reported. This operationally simple catalytic reaction furnishes tosyl-protected vinyl-oxazolidinones, common precursors to syn-1,2-amino alcohols, in high yield and excellent diasteroselectivity (>20:1). It is demonstrated that both stoichiometric amounts of benzoquinone (BQ) as well as aerobic reoxidation (molecular oxygen) is suitable for this transformation. The title reaction is shown to proceed through overall trans-amidopalladation of the olefin followed by beta-hydride elimination. This process is scalable and the products are suitable for a range of subsequent transformations such as: kinetic resolution (KR) and oxidative Heck-, Wacker-, and metathesis reactions.

  • 16.
    Kärkäs, Markus D.
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Verho, Oscar
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Johnston, Eric V.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Artificial Photosynthesis: Molecular Systems for Catalytic Water Oxidation2014In: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 114, no 24, p. 11863-12001Article, review/survey (Refereed)
  • 17. Küpper, Frithjof C.
    et al.
    Feiters, Martin C.
    Olofsson, Berit
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Kaiho, Tatsuo
    Yanagida, Shozo
    Zimmermann, Michael B.
    Carpenter, Lucy J.
    Luther, George W., III
    Lu, Zunli
    Jonsson, Mats
    Kloo, Lars
    Commemorating Two Centuries of Iodine Research: An Interdisciplinary Overview of Current Research2011In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 50, no 49, p. 11598-11620Article, review/survey (Refereed)
    Abstract [en]

    Iodine was discovered as a novel element in 1811 during the Napoleonic Wars. To celebrate the bicentennial anniversary of this event we reflect on the history and highlight the many facets of iodine research that have evolved since its discovery. Iodine has an impact on many aspects of life on Earth as well as on human civilization. It is accumulated in high concentrations by marine algae, which are the origin of strong iodine fluxes into the coastal atmosphere which influence climatic processes, and dissolved iodine is considered a biophilic element in marine sediments. Iodine is central to thyroid function in vertebrates, with paramount implications for human health. Iodine can exist in a wide range of oxidation states and it features a diverse supramolecular chemistry. Iodine is amenable to several analytical techniques, and iodine compounds have found widespread use in organic synthesis. Elemental iodine is produced on an industrial scale and has found a wide range of applications in innovative materials, including semiconductorsin particular, in solar cells.

  • 18. Larhed, M
    et al.
    Hallberg, A
    Microwave-assisted high-speed chemistry: a new technique in drug discovery2001In: Drug Discovery Today, ISSN 1359-6446, E-ISSN 1878-5832, Vol. 6, no 8, p. 406-416Article, review/survey (Refereed)
    Abstract [en]

    In both lead identification and lead optimization processes there is an acute need for new organic small molecules. Traditional methods of organic synthesis are orders of magnitude too slow to satisfy the demand for these compounds. The fields of combinatorial and automated medicinal chemistry have been developed to meet the increasing requirement of new compounds for drug discovery; within these fields, speed is of the essence. The efficiency of microwave flash-heating chemistry in dramatically reducing reaction times (reduced from days and hours to minutes and seconds) has recently been proven in several different fields of organic chemistry. We believe that the time saved by using focused microwaves is potentially important in traditional organic synthesis but could be of even greater importance in high-speed combinatorial and medicinal chemistry.

  • 19. Larhed, M
    et al.
    Moberg, C
    Hallberg, A
    Microwave-accelerated homogeneous catalysis in organic chemistry2002In: Accounts of Chemical Research, ISSN 0001-4842, E-ISSN 1520-4898, Vol. 35, no 9, p. 717-727Article, review/survey (Refereed)
    Abstract [en]

    The efficiency of microwave flash heating in accelerating organic transformations (reaction times reduced from days and hours to minutes and seconds) has recently-been proven in several different fields of organic chemistry. This specific account mainly summarizes our own experiences in developing rapid, robust, and selective microwave-assisted transition metal-catalyzed homogeneous reactions. Applications include selective Heck couplings, cross-couplings, and asymmetric substitutions. The science of green chemistry was developed to meet the increasing demand for environmentally benign chemical processes. We believe the combination of metal catalysis and microwave heating will be of importance in the search for green laboratory-scale synthesis.

  • 20.
    Larik, Fayaz Ali
    et al.
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    Saeed, Aamer
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    Muqadar, Urooj
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    El-Seedi, Hesham
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Faisal, Muhammad
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    Channar, Pervaiz Ali
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    Mehfooz, Haroon
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    The role of Lawesson's reagent in the total synthesis of macrocyclic natural products2017In: Phosphorus Sulfur and Silicon and the Related Elements, ISSN 1042-6507, E-ISSN 1563-5325, Vol. 192, no 5, p. 490-502Article, review/survey (Refereed)
    Abstract [en]

    This review, including 111 references, describes the applications of Lawesson's reagent (LR) [2,4-bis(p-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-dithione] for the total synthesis of macrocyclic natural products. LR is a versatile reagent and shows excellent regioselectivity, chemoselectivity, and offers the products in high yield. The thionation of carbonyl moieties present in macrocyclic natural products, and cyclization to construct key heterocyclic fragments is described. Moreover, this review highlights the medicinal significance of the natural products. [GRAPHICS] .

  • 21. Liao, Rong-Zhen
    et al.
    Siegbahn, Per E. M.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Quantum Chemical Modeling of Homogeneous Water Oxidation Catalysis2017In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 10, no 22, p. 4236-4263Article, review/survey (Refereed)
    Abstract [en]

    The design of efficient and robust water oxidation catalysts has proven challenging in the development of artificial photosynthetic systems for solar energy harnessing and storage. Tremendous progress has been made in the development of homogeneous transition-metal complexes capable of mediating water oxidation. To improve the efficiency of the catalyst and to design new catalysts, a detailed mechanistic understanding is necessary. Quantum chemical modeling calculations have been successfully used to complement the experimental techniques to suggest a catalytic mechanism and identify all stationary points, including transition states for both O-O bond formation and O-2 release. In this review, recent progress in the applications of quantum chemical methods for the modeling of homogeneous water oxidation catalysis, covering various transition metals, including manganese, iron, cobalt, nickel, copper, ruthenium, and iridium, is discussed.

  • 22.
    Lundberg, Helena
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Adolfsson, Hans
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Catalytic α-Alkylation/Reduction of Ketones with Primary Alcohols To Furnish Secondary Alcohols2016In: Synthesis (Stuttgart), ISSN 0039-7881, E-ISSN 1437-210X, Vol. 48, no 5, p. 644-652Article, review/survey (Refereed)
    Abstract [en]

    The formation of secondary alcohol products via a tandem -alkylation/transfer hydrogenation of ketones with primary alcohols is a little explored reaction with unrealized potential for green synthesis. This review covers the current literature in the field, including asymmetric versions of the reaction, and outlines future possibilities and challenges for the methodology. 1 Introduction 2 Formation of Racemic Alcohols 3 Formation of Enantiomerically Enriched Alcohols 4 Conclusions

  • 23.
    Lundberg, Helena
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Tinnis, Fredrik
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Selander, Nicklas
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Adolfsson, Hans
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Catalytic amide formation from non-activated carboxylic acids and amines2014In: Chemical Society Reviews, ISSN 0306-0012, E-ISSN 1460-4744, Vol. 43, no 8, p. 2714-2742Article, review/survey (Refereed)
    Abstract [en]

    The amide functionality is found in a wide variety of biological and synthetic structures such as proteins, polymers, pesticides and pharmaceuticals. Due to the fact that synthetic amides are still mainly produced by the aid of coupling reagents with poor atom-economy, the direct catalytic formation of amides from carboxylic acids and amines has become a field of emerging importance. A general, efficient and selective catalytic method for this transformation would meet well with the increasing demands for green chemistry procedures. This review covers catalytic and synthetically relevant methods for direct condensation of carboxylic acids and amines. A comprehensive overview of homogeneous and heterogeneous catalytic methods is presented, covering biocatalysts, Lewis acid catalysts based on boron and metals as well an assortment of other types of catalysts.

  • 24.
    Marshall, Garland R
    et al.
    Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, United States..
    Ballante, Flavio
    Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, United States..
    Limiting Assumptions in the Design of Peptidomimetics2017In: Drug development research (Print), ISSN 0272-4391, E-ISSN 1098-2299, Vol. 78, no 6, p. 245-267Article, review/survey (Refereed)
    Abstract [en]

    Limiting the flexibility of organic compounds to enhance their affinity and selectivity for targeting a macromolecule involved in molecular recognition has become a well-developed paradigm in medicinal chemistry. While the role of reverse-turn motifs as peptidomimetics has received the most attention, β-sheets and helices are also important motifs for protein/protein interactions. The more complicated problem of mimicking the interacting surface of noncontiguous epitopes will not be considered in this review. This limited overview focuses on efforts to use amino acid synthons as secondary-structure mimetics as well as providing examples of peptidomimetic design focused on nonpeptide synthetic chemistry in contrast. In particular, the rationale of optimal design criteria for mimicry and the many naïve violations of those criteria made in its pursuit are emphasized.

  • 25.
    Merritt, Eleanor A.
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Olofsson, Berit
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Diaryliodonium salts: A journey from obscurity to fame2009In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 48, no 48, p. 9052-9070Article, review/survey (Refereed)
    Abstract [en]

    The recent groundbreaking developments in the application of diaryliodonium salts in cross-coupling reactions has brought this class of previously underdeveloped reagents to the forefront of organic chemistry. With the advent of novel, facile, and efficient synthetic routes to these compounds, many more applications can be foreseen. Herein we provide an overview of the historical and recent advances in the synthesis and applications of diaryliodonium salts.

  • 26.
    Merritt, Eleanor A.
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Olofsson, Berit
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Diaryliodoniumsalze - aus dem Nichts ins Rampenlicht2009In: Angewandte Chemie, ISSN 1521-3757, Vol. 121, no 48, p. 9214-9234Article, review/survey (Refereed)
    Abstract [de]

    Die jüngsten bahnbrechenden Entwicklungen bei der Anwendung von Diaryliodoniumsalzen in Kreuzkupplungsreaktionen haben diese ehemals unterentwickelte Klasse von Reagentien in die vorderste Reihe der organischen Chemie katapultiert. Mit dem Aufkommen neuartiger, einfacher, effizienter Methoden zur Synthese dieser Reagentien lassen sich noch sehr viel mehr Einsatzmöglichkeiten voraussehen. Wir bieten hier einen Überblick über die historischen und neuerlichen Fortschritte bei der Synthese und Anwendung von Diaryliodoniumsalzen.

  • 27.
    Moberg, Christina
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Recycling in Asymmetric Catalysis2016In: ACCOUNTS OF CHEMICAL RESEARCH, ISSN 0001-4842, Vol. 49, no 12, p. 2736-2745Article, review/survey (Refereed)
    Abstract [en]

    CONSPECTUS: Cyclic reaction networks consisting of an enantioselective product forming step and a reverse reaction of the undesired enantiomer back to starting reactant are important for the generation of compounds with high enantiomeric purity. In order to avoid an equilibrium racemic state, a unidirectional cyclic process where product formation and regeneration of starting reactant proceed through different mechanistic pathways is required. Such processes must necessarily include a thermodynamically unfavorable step, since the product of the forward reaction is the reactant of the reverse reaction and vice versa. Thermodynamically uphill processes are ubiquitous to the function of living systems. Such systems gain the required energy by coupling to thermodynamically downhill reactions. In the same way, artificial cyclic reaction networks can be realized in systems open to mass or energy flow, and an out-of equilibrium nonracemic steady state can be maintained as long as the system is supplied with energy. In contrast to a kinetic resolution, a recycling process where the minor enantiomer is converted to starting reactant can result in a quantitative yield, but the enantiomeric purity of the product is limited by the selectivity of the catalysts used for the reactions. On the other hand, in a kinetic resolution, the slowly reacting enantiomer can always be obtained in an enantiomerically pure state, although the yield will suffer. In cyclic reaction systems which use chiral catalysts for both the forward and the reverse processes, a reinforcing effect results, and selectivities higher than those achieved by a single chiral catalyst are observed. A dynamic kinetic resolution can in principle also lead to a quantitative yield, but lacks the reinforcing effect of two chiral catalysts. Most examples of cyclic reaction networks reported in the literature are deracemizations of racemic mixtures, which proceed via oxidation of one enantiomer followed by reduction to the opposite enantiomer. We have developed cyclic reaction networks comprising a carbon carbon bond formation. In these processes, the product is generated by the addition of a cyanide reagent to a prochiral aldehyde. This is followed by hydrolysis of the minor enantiomer of the product to generate the starting aldehyde. A unidirectional cycle is maintained by coupling to the exergonic transformation of the high potential cyanide reagent to a low potential compound, either a carboxylate or carbon dioxide. The products, which are obtained with high enantiomeric purity, serve as valuable starting materials for a variety of biologically and pharmaceutically active compounds.

  • 28.
    Mowbray, Sherry L
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structure and Molecular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Kathiravan, Muthu K
    Pandey, Abhishek A
    Odell, Luke R
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Inhibition of Glutamine Synthetase: A Potential Drug Target in Mycobacterium tuberculosis2014In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 19, no 9, p. 13161-13176Article, review/survey (Refereed)
    Abstract [en]

    Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Globally, tuberculosis is second only to AIDS in mortality and the disease is responsible for over 1.3 million deaths each year. The impractically long treatment schedules (generally 6-9 months) and unpleasant side effects of the current drugs often lead to poor patient compliance, which in turn has resulted in the emergence of multi-, extensively- and totally-drug resistant strains. The development of new classes of anti-tuberculosis drugs and new drug targets is of global importance, since attacking the bacterium using multiple strategies provides the best means to prevent resistance. This review presents an overview of the various strategies and compounds utilized to inhibit glutamine synthetase, a promising target for the development of drugs for TB therapy.

  • 29.
    Månsson, Alf
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Balaz, Martina
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Torres, Nuria Albet
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Rosengren, Johan
    University of Kalmar, School of Pure and Applied Natural Sciences.
    In vitro assays of molecular motors - impact of motor-surface interactions2008In: Frontiers in Bioscience, ISSN 1093-9946, E-ISSN 1093-4715, Vol. 13, no May 1, p. 5732-5754Article, review/survey (Other academic)
    Abstract [en]

    In many types of biophysical studies of both single molecules and ensembles of molecular motors the motors are adsorbed to artificial surfaces. Some of the most important assay systems of this type (in vitro motility assays and related single molecule techniques) will be briefly described together with an account of breakthroughs in the understanding of actomyosin function that have resulted from their use. A poorly characterized, but potentially important, entity in these studies is the mechanism of motor adsorption to surfaces and the effects of motor surface interactions on experimental results. A better understanding of these phenomena is also important for the development of commercially viable nanotechnological applications powered by molecular motors. Here, we will consider several aspects of motor surface interactions with a particular focus on heavy meromyosin (HMM) from skeletal muscle. These aspects will be related to heavy meromyosin structure and relevant parts of the vast literature on protein-surface interactions for non-motor proteins. An overview of methods for studying motor-surface interactions will also be given. The information is used as a basis for further development of a model for HMM-surface interactions and is discussed in relation to experiments where nanopatterning has been employed for in vitro reconstruction of actomyosin order. The challenges and potentials of this approach in biophysical studies, compared to the use of self-assembly of biological components into supramolecular protein aggregates (e. g. myosin filaments) will be considered. Finally, this review will consider the implications for further developments of motor-powered lab-on-a-chip devices.

  • 30.
    Nicholls, Ian A.
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Andersson, Håkan S.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Golker, Kerstin
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Henschel, Henning
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Karlsson, Björn C. G.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsson, Gustaf D.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rosengren, Annika M.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Shoravi, Siamak
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Wiklander, Jesper G.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Wikman, Susanne
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rational Design of Biomimetic Molecularly Imprinted Materials: Theoretical and Computational Strategies for Guiding Nanoscale Structured Polymer Development2011In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 400, p. 1771-1786Article, review/survey (Refereed)
    Abstract [en]

    In principle, molecularly imprinted polymer science and technology provides a means for ready access to nano-structured polymeric materials of predetermined selectivity. The versatility of the technique has brought it to the attention of many working with the development of nanomaterials with biological or biomimetic properties for use as therapeutics or in medical devices. Nonetheless, the further evolution of the field necessitates the development of robust predictive tools capable of handling the complexity of molecular imprinting systems. The rapid growth in computer power and software over the past decade has opened new possibilities for simulating aspects of the complex molecular imprinting process. We present here a survey of the current status of the use of in silico-based approaches to aspects of molecular imprinting. Finally, we highlight areas where ongoing and future efforts should yield information critical to our understanding of the underlying mechanisms sufficient to permit the rational design of molecularly imprinted polymers.

  • 31.
    Norgren, Magnus
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Lignin: Recent advances and emerging applications2014In: Current Opinion in Colloid & Interface Science, ISSN 1359-0294, E-ISSN 1879-0399, Vol. 19, p. 409-416Article, review/survey (Refereed)
    Abstract [en]

    In this paper, we focus on the recent advances on the physical chemistry of lignin. Emerging trends of incorporating lignin in promising future applications such as controlled release, saccharification of lignocelluloses, bioplastics, composites, nanoparticles, adsorbents and dispersants, in electro-chemical applications and carbon fi bers, arealso reviewed. We briefl y describe the complexity of the lignin structure that influences the solution behavior, both as a macromolecule and a col loid, as well as the potential of being a renewable precursor in the development of high-value applications. Special attention is paid on summarizing the present knowledge on lignin colloidalstability and surface chemistry.

  • 32.
    Ottosson, Henrik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Eklöf, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Silenes: Connectors between classical alkenes and nonclassical heavy alkenes2008In: Coordination chemistry reviews, ISSN 0010-8545, E-ISSN 1873-3840, Vol. 252, no 12-14, p. 1287-1314Article, review/survey (Refereed)
    Abstract [en]

    Forty years have passed since the first publication of the experimental evidence for formation of a SiC double bonded compound, a silene. Since then, a large number of transient as well as isolable silenes have been studied, both experimentally and theoretically. Herein, we focus on the impact of the substituents on the electronic and geometric structure, reactivity, and other properties of (formally) SiC double bonded compounds. Qualitative quantum chemical models for the bonding are reviewed, and applied to rationalize experimental observations. Silenes can have planar (classical) structures similar to alkenes, or nonplanar (nonclassical) structures similar to the heavier alkene congeners, and their substituents are pivotal in determining which of these structures is adopted. Silene properties, ranging from charge distribution and NMR chemical shifts to reactivities, are strongly connected to the electronic structure of the silene, and thus to its substitution pattern.

  • 33.
    Pace, Vittorio
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry. University of Vienna, Austria.
    Holzer, Wolfgang
    Olofsson, Berit
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Increasing the Reactivity of Amides towards Organometallic Reagents: An Overview2014In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 356, no 18, p. 3697-3736Article, review/survey (Refereed)
    Abstract [en]

    The nucleophilic addition of carbon nucleophiles to amides has traditionally been a difficult task, both due to reactivity and selectivity problems. When successful, these processes would represent straightforward routes towards carbonyl-type or amine compounds, depending on the fate of the generated tetrahedral intermediate. The direct addition of nucleophiles to amides for the preparation of ketones has been studied and applied to the syntheses of several natural products. On the other hand, the addition of nucleophiles to amides to obtain substituted amines represented a major challenge, and only scattered applications on particular substrates have appeared. Initial improvements were based on the activation of amides by introduction of particular substituents, such as in N-methoxy amides (Weinreb amides) or electron-withdrawing groups able to increase the carbon nucleophilicity. Although these strategies facilitate the introduction of nucleophiles, chemoselectivity issues arise when additional electrophilic moieties (i.e., carbonyls) are present, thus decreasing the versatility of the methods. In recent years, important advancements towards fully chemoselective methods have been realized. The capture of tetrahedral intermediates with acids generates highly electrophilic iminium species able to undergo chemoselective additions of various nucleophiles, thus accessing substituted amines. Alternatively, the in situ generation of an iminium triflate ion allows highly chemoselective additions of nucleophiles, yielding amines, ketones or ketimines. Also thioamides can be used as precursors of ketones or alpha-substituted amines. The success of the above methodologies is further showcased by the application in various syntheses of natural products or biologically active molecules.

  • 34.
    Pu, Maoping
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Privalov, Timofei
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Chemistry of Intermolecular Frustrated Lewis Pairs in Motion: Emerging Perspectives and Prospects2015In: Israel Journal of Chemistry, ISSN 0021-2148, Vol. 55, no 2, p. 179-195Article, review/survey (Refereed)
    Abstract [en]

    This feature article describes the chemistry in motion of frustrated Lewis pairs (FLPs). With state-of-the-art ab initio molecular dynamics (AIMD) simulations supplemented by minimum energy path (MEP) and potential energy surface (PES) calculations, we examine the binding of CO2 and the heterolytic cleavage of H-2 by a Lewis base (LB), tBu(3)P, and a Lewis acid (LA), B(C6F5)(3). We strive to uncover and understand mechanistic implications of the physical laws that govern the behavior of a LB and a LA when they react with a third species (e.g., CO2 or H-2) at finite temperature. The approximation that we necessarily must make at present is to forgo the quantization of the movement of atoms in favor of the Born-Oppenheimer molecular dynamics (BOMD), which unfold according to the classical (Newton's) laws of motion. However, strict quantum chemical theory is used to compute all of the forces that govern the dynamics of the macromolecular FLP system. Using physical reasoning and innovative computer simulations, we show that multi-scale motion is the predominant mechanistic aspect in reactions of the tBu(3)P/B(C6F5)(3) FLP, as well as, conceivably, those of other similar intermolecular FLPs. Insight achieved thus far leads to a novel activity model for intermolecular FLPs and specific predictions, which could be useful for future experimental and theoretical studies of FLP and other chemistries.

  • 35. Rios, Ramón
    et al.
    Córdova, Armando
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Examples of catalytic asymmetric amine synthesis using organic catalysts2009In: Current opinion in drug discovery & development, ISSN 1367-6733, E-ISSN 2040-3437, Vol. 12, no 6, p. 824-847Article, review/survey (Refereed)
  • 36.
    Roslin, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Odell, Luke R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Visible-Light Photocatalysis as an Enabling Tool for the Functionalization of Unactivated C(sp(3))-Substrates2017In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, Vol. 2017, no 15, p. 1993-2007Article, review/survey (Refereed)
    Abstract [en]

    Over the past decade, visible-light photocatalysis has emerged as one of the brightest and most dynamic fields in modern organic chemistry. By employing a transition-metal- or organic-dye-based photocatalyst in conjunction with a low-energy visible-light source, this synthetic manifold allows the facile generation of radical intermediates that can subsequently be directed through a wide range of transformations. Although initial studies focused largely on the functionalization of stabilized radical intermediates, over the past few years significant efforts have been directed towards the functionalization of challenging unactivated radical precursors. In this review we summarize the recent developments in the use of visible-light photocatalysis for the functionalization of unactivated C(sp(3))-substrates.

  • 37.
    Rybacka, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Ruden, Christina
    Andersson, Patrik L.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    On the Use of In Silico Tools for Prioritising Toxicity Testing of the Low-Volume Industrial Chemicals in REACH2014In: Basic & Clinical Pharmacology & Toxicology, ISSN 1742-7835, E-ISSN 1742-7843, Vol. 115, no 1, p. 77-87Article, review/survey (Refereed)
    Abstract [en]

    This study was conducted to evaluate the utility of a selection of commercially and freely available non-testing tools and to analyse how REACH registrants can apply these as prioritisation tool for low-volume chemicals. The analysis was performed on a set of organic industrial chemicals and pesticides with extensive peer-reviewed risk assessment data. Analysed in silico model systems included Derek Nexus, Toxtree, QSAR Toolbox, LAZAR, TEST and VEGA, and results from these were compared with expert-judged risk classification according to the classifying, labelling and packaging (CLP) regulation. The most reliable results were obtained for carcinogenicity; however, less reliable predictions were derived for mutagenicity and reproductive toxicity. A group of compounds frequently predicted as false negatives was identified. These were relatively small molecules with low structural complexity, for example benzene derivatives with hydroxyl-, amino- or aniline-substituents. A rat liver S9 metabolite simulator was applied to illustrate the importance of considering metabolism in the risk assessment procedure. We also discuss outcome of combining predictions from multiple model systems and advise how to apply in silico tools. These models are proposed to be used to prioritise low-volume chemicals for testing within the REACH legislation, and we conclude that further guidance is needed so that industry can select and apply models in a reliable, systematic and transparent way.

  • 38.
    Saeed, Aamer
    et al.
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    Larik, Fayaz Ali
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    Lal, Bhajan
    Sukkur Inst Business Adm, Dept Energy Syst Engn, Sukkur, Pakistan..
    Faisal, Muhammad
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    El-Seedi, Hesham
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Channar, Pervaiz Ali
    Quaid I Azam Univ, Dept Chem, Islamabad, Pakistan..
    Recent resurgence toward the oxidation of heteroatoms using dimethyldioxirane as an exquisite oxidant2017In: Synthetic Communications, ISSN 0039-7911, E-ISSN 1532-2432, Vol. 47, no 9, p. 835-852Article, review/survey (Refereed)
    Abstract [en]

    This review covers the literature from 2005 to till date. Oxidation chemistry is a dynamic field of organic synthesis as it keeps evolving with the passage of time. There is a recent surge in that area to switch over from inorganic oxidants to organic oxidants. The oxidation of heteroatom is an intriguing task for the synthetic chemists, as it requires mild oxidant with no harmful side products. Dimethyldioxirane serves as a super-effective oxidant as it shows high functional group tolerance and possess acetone as byproducts which is also eco-friendly. This review summarizes the heteroatom oxidation of sulfur, nitrogen, iodine, selenium, phosphorous, and platinum atoms using DMDO as an oxidant.

  • 39. Santoro, Stefano
    et al.
    Kalek, Marcin
    Huang, Genping
    Himo, Fahmi
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Elucidation of Mechanisms and Selectivities of Metal-Catalyzed Reactions using Quantum Chemical Methodology2016In: Accounts of Chemical Research, ISSN 0001-4842, E-ISSN 1520-4898, Vol. 49, no 5, p. 1006-1018Article, review/survey (Refereed)
    Abstract [en]

    Quantum chemical techniques today are indispensable for the detailed mechanistic understanding of catalytic reactions. The development of modem density functional theory approaches combined with the enormous growth in computer power have made it possible to treat quite large systems at a reasonable level of accuracy. Accordingly, quantum chemistry has been applied extensively to a wide variety of catalytic systems. A huge number of problems have been solved successfully, and vast amounts of chemical insights have been gained. In this Account, we summarize some of our recent work in this field. A number of examples concerned with transition metal-catalyzed reactions are selected, with emphasis on reactions with various kinds of selectivities. The discussed cases are (1) copper-catalyzed C-H bond amidation of indoles, (2) iridium-catalyzed C(sp(3))-H borylation of chlorosilanes, (3) vanadium-catalyzed Meyer-Schuster rearrangement and its combination with aldol- and Mannich-type additions, (4) palladium-catalyzed propargylic substitution with phosphorus nucleophiles, (5) rhodium-catalyzed 1:2 coupling of aldehydes and allenes, and finally (6) copper-catalyzed coupling of nitrones and alkynes to produce beta-lactams (Kinugasa reaction). First, the methodology adopted in these studies is presented briefly. The electronic structure method in the great majority of these kinds of mechanistic investigations has for the last two decades been based on density functional theory. In the cases discussed here, mainly the B3LYP functional has been employed in conjunction with Grimme's empirical dispersion correction, which has been shown to improve the calculated energies significantly. The effect of the surrounding solvent is described by implicit solvation techniques, and the thermochemical corrections are included using the rigid-rotor harmonic oscillator approximation. The reviewed examples are chosen to illustrate the usefulness and versatility of the adopted methodology in solving complex problems and proposing new detailed reaction mechanisms that rationalize the experimental findings. For each of the considered reactions, a consistent mechanism is presented, the experimentally observed selectivities are reproduced, and their sources are identified. Reproducing selectivities requires high accuracy in computing relative transition state energies. As demonstrated by the results summarized in this Account, this accuracy is possible with the use of the presented methodology, benefiting of course from a large extent of cancellation of systematic errors. It is argued that as the employed models become larger, the number of rotamers and isomers that have to be considered for every stationary point increases and a careful assessment of their energies is therefore necessary in order to ensure that the lowest energy conformation is located. This issue constitutes a bottleneck of the investigation in some cases and is particularly important when analyzing selectivities, since small energy differences need to be reproduced.

  • 40. Scrimin, P.
    et al.
    Baltzer, Lars
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Model Systems2005In: Editorial Overwiev, Current Opinion of Chemical Biology, no 9, p. 620-621Article, review/survey (Other (popular scientific, debate etc.))
  • 41.
    Seashore-Ludlow, Brinton
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    1,3-Bis(silyl)propenes2011In: E-EROS ENCYCLOPEDIA OF REAGENTS FOR ORGANIC SYNTHESISArticle, review/survey (Other academic)
  • 42.
    Selander, Nicklas
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Szabó, Kálmán J.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Catalysis by Palladium Pincer Complexes2011In: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 111, no 3, p. 2048-2076Article, review/survey (Refereed)
  • 43. Silva, Luiz F., Jr.
    et al.
    Olofsson, Berit
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Hypervalent iodine reagents in the total synthesis of natural products2011In: Natural product reports (Print), ISSN 0265-0568, E-ISSN 1460-4752, Vol. 28, no 10, p. 1722-1754Article, review/survey (Refereed)
    Abstract [en]

    This report describes the recent applications of hypervalent iodine reagents in the total synthesis of natural products. The large diversity of high-yielding and chemoselective reactions that can be achieved, even for highly functionalized molecules, is summarized, demonstrating that hypervalent iodine reagents have become an essential tool in synthetic organic chemistry.

  • 44. Smilowitz, Jennifer T.
    et al.
    Zivkovic, Angela M.
    Wan, Yu-Jui Yvonne
    Watkins, Steve M.
    Nording, Malin L.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Hammock, Bruce D.
    German, J. Bruce
    Nutritional lipidomics: Molecular metabolism, analytics, and diagnostics2013In: Molecular Nutrition & Food Research, ISSN 1613-4125, E-ISSN 1613-4133, Vol. 57, no 8, p. 1319-1335Article, review/survey (Refereed)
    Abstract [en]

    MS with new bioinformatics toolsets to characterize the structures and abundances of complex lipids. Yet, translating lipidomics to practice via nutritional interventions is still in its infancy. No single instrumentation platform is able to solve the varying analytical challenges of the different molecular lipid species. Biochemical pathways of lipid metabolism remain incomplete and the tools to map lipid compositional data to pathways are still being assembled. Biology itself is dauntingly complex and simply separating biological structures remains a key challenge to lipidomics. Nonetheless, the strategy of combining tandem analytical methods to perform the sensitive, high-throughput, quantitative, and comprehensive analysis of lipid metabolites of very large numbers of molecules is poised to drive the field forward rapidly. Among the next steps for nutrition to understand the changes in structures, compositions, and function of lipid biomolecules in response to diet is to describe their distribution within discrete functional compartments lipoproteins. Additionally, lipidomics must tackle the task of assigning the functions of lipids as signaling molecules, nutrient sensors, and intermediates of metabolic pathways.

  • 45. Stamatov, Stephan D.
    et al.
    Stawinski, Jacek
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    O-Silylated C3-halohydrins as a novel class of protected building blocks for total, regio- and stereocontrolled synthesis of glycerolipid frameworks2010In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 8, no 2, p. 463-477Article, review/survey (Refereed)
    Abstract [en]

    We propose O-silylated C3-halohydrins [1(3)-O-silyl-2-O-acyl-, 1,2(2,3)-O-bis(silyl)-, and 1(3)-O-acyl-2-O-silyl-3(1)-halo-sn-glycerides] as new chirons in the total synthesis of glycerolipid constructs. These are efficiently producible via opening of the oxirane ring of the corresponding glycidyl derivatives and permit (i) displacement of the iodine by a requisite carboxylate in the presence of O-triisopropylsilyl (O-TIPS), O-tert-butyldimethylsilyl (O-TBDMS), and O-acyl substituents; (ii) selective acylation across an appropriate silyloxy system [e. g., O-TBDMS or O-triethylsilyl (O-TES)] of monoesterified haloglycerides; (iii) direct exchange of an O-silyl protection (e. g., O-TBDMS or O-TIPS) for a trichloroacetyl group; (iv) conversion of a terminal TBDMS group into the corresponding trifluoroacetate without affecting O-TIPS-, O-acyl- and iodo functions. The above transformations secure flexible routes to a variety of otherwise difficult-to-access key-intermediates [e.g., 1,2(2,3)-O-bis(acyl)-3(1)-trichloroacetyl-, 1,3-O-bis(acyl)-2-trichloroacetyl-, 1,2(2,3)-O-bis(acyl)-3(1)-O-TBDMS/TIPS-, 1,3-O-bis(acyl)-2-O-TIPS/TBDMS-, 1(3)-O-acyl-2-O-TIPS-, 1,2(2,3)-O-bis(acyl)-3(1)-iodo-sn-glycerols, etc.] and lend themselves to a powerful methodology for the preparation of di- and triacylglycerols as well as glycerol-based cationic lipids. The reactions involved are entirely regio- and stereospecific, avoid acyl migration, and can provide target compounds with a chosen absolute configuration from a single synthetic precursor.

  • 46. Szijjarto, Csongor
    et al.
    Pershagen, Elias
    Stockholm University, Faculty of Science, Department of Organic Chemistry. Uppsala University, Sweden.
    Ilchenko, Nadia O.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Borbas, K. Eszter
    Stockholm University, Faculty of Science, Department of Organic Chemistry. Uppsala University, Sweden.
    A Versatile Long-Wavelength-Absorbing Scaffold for Eu-Based Responsive Probes2013In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 19, no 9, p. 3099-3109Article, review/survey (Refereed)
    Abstract [en]

    Coumarin-sensitized, long-wavelength-absorbing luminescent EuIII-complexes have been synthesized and characterized. The lanthanide binding site consists of a cyclen-based chelating framework that is attached through a short linker to a 7-hydroxycoumarin, a 7-B(OH)2-coumarin, a 7-O-(4-pinacolatoboronbenzyl)-coumarin or a 7-O-(4-methoxybenzyl)-coumarin. The syntheses are straightforward, use readily available building blocks, and proceed through a small number of high-yielding steps. The sensitivity of coumarin photophysics to the 7-substituent enables modulation of the antenna-absorption properties, and thus the lanthanide excitation spectrum. Reactions of the boronate-based functionalities (cages) with H2O2 yielded the corresponding 7-hydroxycoumarin species. The same species was produced with peroxynitrite in a x106107-fold faster reaction. Both reactions resulted in the emergence of a strong approximate to 407nm excitation band, with concomitant decrease of the 366nm band of the caged probe. In aqueous solution the methoxybenzyl caged Eu-complex was quenched by ONOO. We have shown that preliminary screening of simple coumarin-based antennae through UV/Vis absorption spectroscopy is possible as the changes in absorption profile translate with good fidelity to changes in EuIII-excitation profile in the fully elaborated complex. Taken together, our results show that the 7-hydroxycoumarin antenna is a viable scaffold for the construction of turn-on and ratiometric luminescent probes.

  • 47. Tran, Rosalie
    et al.
    Kern, Jan
    Hattne, Johan
    Koroidov, Sergey
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Hellmich, Julia
    Alonso-Mori, Roberto
    Sauter, Nicholas K.
    Bergmann, Uwe
    Messinger, Johannes
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Zouni, Athina
    Yano, Junko
    Yachandra, Vittal K.
    The Mn4Ca photosynthetic water-oxidation catalyst studied by simultaneous X-ray spectroscopy and crystallography using an X-ray free-electron laser2014In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 369, no 1647, p. 20130324-Article, review/survey (Refereed)
    Abstract [en]

    The structure of photosystem II and the catalytic intermediate states of the Mn4CaO5 cluster involved in water oxidation have been studied intensively over the past several years. An understanding of the sequential chemistry of light absorption and the mechanism of water oxidation, however, requires a new approach beyond the conventional steady-state crystallography and X-ray spectroscopy at cryogenic temperatures. In this report, we present the preliminary progress using an X-ray free-electron laser to determine simultaneously the light-induced protein dynamics via crystallography and the local chemistry that occurs at the catalytic centre using X-ray spectroscopy under functional conditions at room temperature.

  • 48.
    Volkov, Alexey
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Tinnis, Fredrik
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Stagbrand, Tove
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Trillo, Paz
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Adolfsson, Hans
    Chemoselective reduction of carboxamides2016In: Chemical Society Reviews, ISSN 0306-0012, E-ISSN 1460-4744, Vol. 45, no 24, p. 6685-6697Article, review/survey (Refereed)
    Abstract [en]

    The reduction of amides gives access to a wide variety of important compounds such as amines, imines, enamines, nitrites, aldehydes and alcohols. The chemoselective transformation into these functional groups is challenging due to the intrinsic stability of the amide bond; nevertheless, the ability to reduce highly stable carboxamides selectively in the presence of sensitive functional groups is of high synthetic value for academic and industrial chemists. Hydride-based reagents such as LiAlH4 or diboranes are today the most commonly used compounds for amide reductions, and apart from the substantial amount of waste generated using these methods, they lack tolerance to most other functional groups. This tutorial review provides an overview of the recent progress made in the development of chemoselective protocols for amide reduction and gives an insight to their advantages and drawbacks.

  • 49. Volkov, Atexey
    et al.
    Tinnis, Fredrik
    Stagbrand, Tove
    Trillo, Paz
    Adolfsson, Hans
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Chemoselective reduction of carboxamides2016In: Chemical Society Reviews, ISSN 0306-0012, E-ISSN 1460-4744, Vol. 45, no 24, p. 6685-6697Article, review/survey (Refereed)
    Abstract [en]

    The reduction of amides gives access to a wide variety of important compounds such as amines, imines, enamines, nitrites, aldehydes and alcohols. The chemoselective transformation into these functional groups is challenging due to the intrinsic stability of the amide bond; nevertheless, the ability to reduce highly stable carboxamides selectively in the presence of sensitive functional groups is of high synthetic value for academic and industrial chemists. Hydride-based reagents such as LiAlH4 or diboranes are today the most commonly used compounds for amide reductions, and apart from the substantial amount of waste generated using these methods, they lack tolerance to most other functional groups. This tutorial review provides an overview of the recent progress made in the development of chemoselective protocols for amide reduction and gives an insight to their advantages and drawbacks.

  • 50.
    Yang, Bin
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Qiu, Youai
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Bäckvall, Jan-E.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Control of Selectivity in Palladium(II)-Catalyzed Oxidative Transformations of Allenes2018In: Accounts of Chemical Research, ISSN 0001-4842, E-ISSN 1520-4898, Vol. 51, no 6, p. 1520-1531Article, review/survey (Refereed)
    Abstract [en]

    Oxidation reactions play a central role in organic synthesis, and it is highly desirable that these reactions are mild and occur under catalytic conditions. In Nature, oxidation reactions occur under mild conditions via cascade processes, and furthermore, they often occur in an enantioselective manner with many of them involving molecular oxygen or hydrogen peroxide as the terminal oxidant. Inspired by the reactions in Nature, we have developed a number of Pd(II)-catalyzed cascade reactions under mild oxidative conditions. These reactions have an intrinsic advantage of step economy and rely on selectivity control in each step. In this Account, we will discuss the control of chemo-, regio-, and diastereoselectivity in Pd(II)-catalyzed dehydrogenative cascade coupling reactions. The enantioselective version of this methodology has also been addressed, and new chiral centers have been introduced using a catalytic amount of a chiral phosphoric acid (CPA). Research on this topic has provided access to important compounds attractive for synthetic and pharmaceutical chemists. These compounds include carbocyclic, heterocyclic, and polycyclic systems, as well as polyunsaturated open-chain structures. Reactions leading to these compounds are initiated by coordination of an allene and an unsaturated pi-bond moiety, such as olefin, alkyne, or another allene, to the Pd(II) center, followed by allene attack involving a C(sp(3))-H cleavage under mild reaction conditions. Recent progress within our research group has shown that weakly coordinating groups (e.g., hydroxyl, alkoxide, or ketone) could also initiate the allene attack on Pd(II), which is essential for the oxidative carbocyclization. Furthermore, a highly selective palladium-catalyzed allenic C(sp(3))-H bond oxidation of allenes in the absence of an assisting group was developed, which provides a novel and straightforward synthesis of [3]dendralene derivatives. For the oxidative systems, benzoquinone (BQ) and its derivatives are commonly used as oxidants or catalytic co-oxidants (electron transfer mediators, ETMs) together with molecular oxygen. A variety of transformations including carbocyclization, acetoxylation, arylation, carbonylation, borylation, beta-hydride elimination, alkynylation, alkoxylation, and olefination have been demonstrated to be compatible with this Pd(II)-based catalytic oxidative system. Recently, several challenging synthetic targets, such as cyclobutenes, seven-membered ring carbocycles, spirocyclic derivatives, functional cyclohexenes, and chiral cyclopentenone derivatives were obtained with high selectivity using these methods. The mechanisms of the reactions were mainly studied by kinetic isotope effects (KIEs) or DFT computations, which showed that in most cases the C(sp(3))-H cleavage is the rate-determining step (RDS) or partially RDS. This Account will describe our efforts toward the development of highly selective and atom-economic palladium(II)-catalyzed oxidative transformation of allenes (including enallenes, dienallenes, bisallenes, allenynes, simple allenes, and allenols) with a focus on overcoming the selectivity problem during the reactions.

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