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  • 1.
    Aggarwal, Varinder K.
    et al.
    Bristol University.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi. University of Bristol, Bristol, UK.
    Enantioselective α-arylation of cyclohexanones with diaryl iodonium salts: Application to the synthesis of (-)-epibatidine.2005Ingår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 44, nr 34, s. 5516-5519Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The direct asym. α-arylation of prochiral ketones has been effected using chiral lithium amide bases and diaryl iodonium salts. The methodol. has been employed in a short total synthesis of the alkaloid (-)-epibatidine. [on SciFinder(R)]

  • 2. Ahmad, Anees
    et al.
    Scarassati, Paulo
    Jalalian, Nazli
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi. Universidade de São Paulo, Brazil.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Silva, Luiz F., Jr.
    Oxidative rearrangement of alkenes using in situ generated hypervalent iodine(III)2013Ingår i: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 54, nr 43, s. 5818-5820Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel protocol for the oxidative rearrangement of alkenes using in situ generated hypervalent iodine(III) was developed. This approach uses inexpensive, readily available, and stable chemicals (PhI, mCPBA, and TsOH) giving rearrangement products in yields comparable to those obtained using the more expensive commercially available [hydroxy(tosyloxy)iodo]benzene [HTIB or Koser's reagent]. Additionally, an alternative protocol for the synthesis of 1-methyl-2-tetralone through the one-step epoxidation/rearrangement of 4-methyl-1,2-dihydronaphthalene using mCPBA and TsOH was developed.

  • 3.
    Bielawski, Marcin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Aili, David
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Regiospecific One-Pot Synthesis of Diaryliodonium Tetrafluoroborates from Arylboronic Acids and Aryl Iodides2008Ingår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 73, nr 12, s. 4602-4607Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Diaryliodonium salts have recently received considerable attention as mild arylation reagents in organic synthesis. This paper describes a regiospecific, sequential one-pot synthesis of symmetrical and unsymmetrical diaryliodonium tetrafluoroborates, which are the most popular salts in metal-catalyzed arylations. The protocol is fast and high-yielding and has a large substrate scope. Furthermore, the corresponding diaryliodonium triflates can conveniently be obtained via an in situ anion exchange.

  • 4.
    Bielawski, Marcin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Malmgren, Joel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Pardo, Leticia M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Wikmark, Ylva
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    One-Pot Synthesis and Applications of N-Heteroaryl Iodonium Salts2014Ingår i: ChemistryOpen, ISSN 2191-1363, Vol. 3, nr 1, s. 19-22Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An efficient one-pot synthesis of N-heteroaryl iodonium triflates from the corresponding N-heteroaryl iodide and arene has been developed. The reaction conditions resemble our previous one-pot syntheses, with suitable modifications to allow N-heteroaryl groups. The reaction time is only 30min, and no anion exchange is required. The obtained iodonium salts were isolated in a protonated form, these salts can either be employed directly in applications or be deprotonated prior to use. The aryl groups were chosen to induce chemoselective transfer of the heteroaryl moiety to various nucleophiles. The reactivity and chemoselectivity of these iodonium salts were demonstrated by selectively introducing a pyridyl moiety onto both oxygen and carbon nucleophiles in good yields.

  • 5.
    Bielawski, Marcin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Efficient one-pot synthesis of bis(4-tert-butylphenyl)iodonium triflate2009Ingår i: Organic Syntheses, ISSN 0078-6209, Vol. 86, s. 308-314Artikel i tidskrift (Refereegranskat)
  • 6.
    Bielawski, Marcin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    High-Yielding One-Pot Synthesis of Diaryliodonium Triflates from Arenes and Iodine or Aryl Iodides2007Ingår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, nr 24, s. 2521-2523Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Unsymmetric and symmetric diaryliodonium triflates are synthesized from both electron-deficient and electron-rich substrates in a fast, high yielding, and operationally simple protocol employing arenes and aryl iodides or iodine.

  • 7.
    Bielawski, Marcin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Zhu, Mingzhao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Efficient and General One-Pot Synthesis of Diaryliodonium Triflates: Optimization, Scope and Limitations2007Ingår i: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 349, nr 17-18, s. 2610-2618Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Symmetrical and unsymmetrical diaryliodonium triflates have been synthesized from both electron-deficient and electron-rich arenes and aryl iodides with mCPBA and triflic acid. A thorough investigation of the optimization, scope and limitations has resulted in an improved one-pot protocol that is fast, high-yielding, and operationally simple. The reaction has been extended to the direct synthesis of symmetrical iodonium salts from iodine and arenes, conveniently circumventing the need for aryl iodides.

  • 8.
    Bielawski, Marcin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Zhu, Mingzhao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Efficient and general one-pot synthesis of diaryliodonium triflates: scope and limitations2007Ingår i: SIS Report: The 10th Symposium on Iodine Science, Chiba University, Japan 2007, 2007, s. 19-22Konferensbidrag (Övrigt vetenskapligt)
  • 9.
    Bogár, Krisztián
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Fransson, Ann-Britt L.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Bäckvall, Jan-E.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Asymmetric synthesis of 3,5-disubstituted piperidines by enzyme-metal combo catalysis2006Ingår i: Enzymatic Synthesis, Stockholm, Sweden, 2006Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 10.
    Bouma, M. J.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    7.07 α-Oxygenation of Carbonyl Compounds2014Ingår i: Comprehensive Organic Synthesis II (Second Edition) / [ed] Paul Knochel and Gary A. Molander, Amsterdam: Oxford: Elsevier , 2014, 2nd, s. 213-241Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Abstract The chapter describes synthetically useful strategies for α-oxygenation of carbonyl compounds, with special emphasis on recent methods for catalytic and asymmetric reactions. The oxidation of enolates, enols, enol ethers, and α,β-unsaturated compounds is discussed in detail. Classical oxidation reagents like metal oxides, molecular oxygen, peroxides, and peracids are covered, with asymmetric dihydroxylation of enol ethers giving the highest enantioselectivities together with organocatalytic methods using peroxides. Oxaziridines, nitrosoarenes, and hypervalent iodine compounds are more recently developed α-oxygenation alternatives that allow metal-free oxidations under mild conditions. The combination of nitrosoarenes with organocatalysis is currently the best method for enantioselective α-oxygenations. The area of asymmetric α-oxygenations with hypervalent iodine compounds is currently under development, and high enantioselectivities have only been achieved in intramolecular reactions and epoxidations.

  • 11.
    Bouma, Marinus J.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    General One-Pot Synthesis of Alkynyliodonium Salts and Alkynyl Benziodoxolones from Aryl Iodides2012Ingår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 18, nr 45, s. 14242-14245Artikel i tidskrift (Refereegranskat)
  • 12. Brown, Michael
    et al.
    Delorme, Marion
    Malmedy, Florence
    Malmgren, Joel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Wirth, Thomas
    Synthesis of New Chiral Diaryliodonium Salts2015Ingår i: Synlett: Accounts and Rapid Communications in Synthetic Organic Chemistry, ISSN 0936-5214, E-ISSN 1437-2096, Vol. 26, nr 11, s. 1573-1577Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A structurally diverse range of chiral diaryliodonium salts have been synthesised which have potential application in metal-free stereoselective arylation reactions.

  • 13.
    Dey, Chandan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Lindstedt, Erik
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi. Wallenberg Research Centre at Stellenbosch University, South Africa.
    Metal-Free C-Arylation of Nitro Compounds with Diaryliodonium Salts2015Ingår i: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 17, nr 18, s. 4554-4557Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An efficient, mild, and metal-free arylation of nitro-alkanes with diaryliodonium salts has been developed, giving easy access to tertiary nitro compounds. The reaction proceeds in high yields without the need for excess reagents and can be extended to alpha-arylation of nitroesters. Nitroalkanes were selectively C-arylated in the presence of other easily arylated functional groups, such as phenols and aliphatic alcohols.

  • 14.
    Ghosh, Raju
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Lindstedt, Erik
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Jalalian, Nazli
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Room Temperature, Metal-Free Arylation of Aliphatic Alcohols2014Ingår i: ChemistryOpen, ISSN 2191-1363, Vol. 3, nr 2, s. 54-57Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Diaryliodonium salts are demonstrated as efficient arylating agents of aliphatic alcohols under metal-free conditions. The reaction proceeds at room temperature within 90min to give alkyl aryl ethers in good to excellent yields. Aryl groups with electron-withdrawing substituents are transferred most efficiently, and unsymmetric iodonium salts give chemoselective arylations. The methodology has been applied to the formal synthesis of butoxycaine.

  • 15.
    Ghosh, Raju
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Metal-Free Synthesis of N-Aryloxyimides and Aryloxyamines2014Ingår i: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 16, nr 6, s. 1830-1832Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    N-Hydroxyphthalimide and N-hydroxysuccinimide have been arylated with diaryliodonium salts to provide N-aryloxyimides in excellent yields in short reaction times. A novel hydrolysis under mild and hydrazine-free conditions yielded aryloxyamines, which are valuable building blocks in the synthesis of oxime ethers and benzofurans.

  • 16.
    Ghosh, Raju
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Stridfeldt, Elin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Metal-Free One-Pot Synthesis of Benzofurans2014Ingår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 20, nr 29, s. 8888-8892Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ethyl acetohydroxamate was efficiently arylated with diaryliodonium salts at room temperature under transition-metal-free conditions. The obtained O-arylated products were reacted in situ with ketones under acidic conditions to yield substituted benzo[b]furans through oxime formation, [3,3]-rearrangement, and cyclization in a fast and operationally simple one-pot fashion without using excess reagents. Alternatively, the O-arylated products could be isolated or transformed in situ to aryloxyamines or O-arylaldoximes. The methodology was applied to the synthesis of Stemofuran A and the formal syntheses of Coumestan, Eupomatenoid 6, and (+)-machaeriol B.

  • 17.
    Jalalian, Nazli
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Ishikawa, Eloisa E.
    Universidade de Sao Paulo, Instituto de Quimica.
    Silva Jr., Luiz F.
    Universidade de Sao Paulo, Instituto de Quimica.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Room temperature, metal-free synthesis of diaryl ethers with use of diaryliodonium salts2011Ingår i: Abstracts of Papers, 242nd ACS National Meeting & Exposition, Denver, CO, United States, August 28-September 1, 2011, American Chemical Society , 2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Diaryl ethers are common structural features in numerous natural products and biol. active compds.  Despite more than a century of immense focus on finding efficient synthetic routes to this compd. class, diaryl ethers remain difficult to obtain.  Routes that are catalytic in copper have been developed, but high catalyst loadings, excess reagents, elevated temps. and long reaction times are still needed.  Pd-catalyzed cross-couplings of phenols and aryl halides at temps. up to 100 °C have recently been reported to give high yields of diaryl ethers.  Diaryliodonium salts are non-toxic alternatives to transition metals in the synthesis of diaryl ethers and we have recently developed effective synthetic routes to these salts.  Herein we report a fast, high-yielding synthesis of diaryl ethers.  The reaction conditions are mild, metal-free, and avoid the use of halogenated solvents, additives, or excess reagents.  Precautions to avoid air or moisture are not needed.  The scope includes ortho- and halo-substituted diaryl ethers, which are difficult to obtain by metal-catalyzed protocols .

  • 18.
    Jalalian, Nazli
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Ishikawa, Eloisa E.
    Silva Jr., Luiz F.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Room temperature, metal-free synthesis of diaryl ethers with use of diaryliodonium salts2011Ingår i: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 13, nr 6, s. 1552-1555Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A fast, high-yielding synthesis of diaryl ethers with use of mild and metal-free conditions has been developed. The scope includes bulky orthosubstituteddiaryl ethers, which are difficult to obtain by metal-catalyzed protocols. Halo-substituents, racemization-prone amino acid derivatives,and heteroaromatics are also tolerated. The methodology is expected to be of high utility in the synthesis of complex molecules and in thepharmaceutical industry.

  • 19.
    Jalalian, Nazli
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Asymmetric α-arylation of carbonyl compounds with chiral diaryliodonium salts2009Ingår i: Abstracts of Papers, 238th ACS National Meeting, Washington, DC, United States, August 16-20, 2009, Washington, D.C.: American Chemical Society , 2009Konferensbidrag (Övrigt vetenskapligt)
  • 20.
    Jalalian, Nazli
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Design and asymmetric synthesis of chiral diaryliodonium salts2010Ingår i: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 66, nr 31, s. 5793-5800Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The application of chiral hypervalent iodine reagents in asymmetric synthesis is highly desirable, as the reagents are metal-free, environmentally benign and employed under mild conditions. Three chiral diaryliodonium salts have been designed to provide chemoselectivity and asymmetric induction in asymmetric alpha-phenylation of carbonyl compounds. The synthetic routes to the selected targets are detailed herein, together with a structural investigation into the diastereoselectivity of the alkylation process.

  • 21.
    Jalalian, Nazli
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Synthesis of Koser’s Reagent and Derivatives2013Ingår i: Organic Syntheses, ISSN 0078-6209, Vol. 90, s. 1-9Artikel i tidskrift (Refereegranskat)
  • 22.
    Jalalian, Nazli
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Petersen, Tue B.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Metal-Free Arylation of Oxygen Nucleophiles with Diaryliodonium Salts2012Ingår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 18, nr 44, s. 14140-14149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phenols and carboxylic acids are efficiently arylated with diaryliodonium salts. The reaction conditions are mild, metal free, and avoid the use of halogenated solvents, additives, and excess reagents. The products are obtained in good-to-excellent yields after short reaction times. Steric hindrance is very well tolerated, both in the nucleophile and diaryliodonium salt. The scope includes ortho-and halo-substituted products, which are difficult to obtain by metal-catalyzed protocols. Many functional groups are tolerated, including carbonyl groups, heteroatoms, and alkenes. Unsymmetric salts can be chemoselectively utilized to obtain products with hitherto unreported levels of steric congestion. The arylation has been extended to sulfonic acids, which can be converted to sulfonate esters by two different approaches. With recent advances in efficient synthetic procedures for diaryliodonium salts the reagents are now inexpensive and readily available. The iodoarene byproduct formed from the iodonium reagent can be recovered quantitatively and used to regenerate the diaryliodonium salt, which improves the atom economy.

  • 23.
    Kervefors, Gabriella
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Becker, Antonia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Dey, Chandan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Metal-free formal synthesis of phenoxazine2018Ingår i: Beilstein Journal of Organic Chemistry, ISSN 2195-951X, E-ISSN 1860-5397, Vol. 14, s. 1491-1497Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A transition metal-free formal synthesis of phenoxazine is presented. The key step of the sequence is a high-yielding O-arylation of a phenol with an unsymmetrical diaryliodonium salt to provide an ortho-disubstituted diaryl ether. This species was cyclized to acetylphenoxazine in moderate yield. The overall yield in the three-step sequence is 72% based on recovered diaryl ether. An interesting, unusually stable iodine(III) intermediate in the O-arylation was observed by NMR and could be converted to the product upon longer reaction time.

  • 24. Küpper, Frithjof C.
    et al.
    Feiters, Martin C.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    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 Research2011Ingår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 50, nr 49, s. 11598-11620Artikel, forskningsöversikt (Refereegranskat)
    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.

  • 25. Küpper, Frithjof C.
    et al.
    Feiters, Martin C.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Kaiho, Tatsuo
    Yanagida, Shozo
    Zimmermann, Michael B.
    Carpenter, Lucy J.
    Luther, George W.
    Lu, Zunli
    Jonsson, Mats
    Kloo, Lars
    Purple fumes: the importance of iodine2013Ingår i: Science in School, ISSN 1818-0353, E-ISSN 1818-0361, nr 27, s. 10s. 45-53Artikel i tidskrift (Övrigt vetenskapligt)
  • 26.
    Lindberg, Bo G.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Merritt, Eleanor A.
    Rayl, Melanie
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Liu, Chenxiao
    Parmryd, Ingela
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Faye, Ingrid
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Immunogenic and Antioxidant Effects of a Pathogen-Associated Prenyl Pyrophosphate in Anopheles gambiae2013Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, nr 8, s. e73868-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Despite efficient vector transmission, Plasmodium parasites suffer great bottlenecks during their developmental stages within Anopheles mosquitoes. The outcome depends on a complex three-way interaction between host, parasite and gut bacteria. Although considerable progress has been made recently in deciphering Anopheles effector responses, little is currently known regarding the underlying microbial immune elicitors. An interesting candidate in this sense is the pathogen-derived prenyl pyrophosphate and designated phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), found in Plasmodium and most eubacteria but not in higher eukaryotes. HMBPP is the most potent stimulant known of human V gamma 9V delta 2 T cells, a unique lymphocyte subset that expands during several infections including malaria. In this study, we show that V(Y)9V delta 2 T cells proliferate when stimulated with supernatants from intraerythrocytic stages of Plasmodium falciparum cultures, suggesting that biologically relevant doses of phosphoantigens are excreted by the parasite. Next, we used Anopheles gambiae to investigate the immune-and redox-stimulating effects of HMBPP. We demonstrate a potent activation in vitro of all but one of the signaling pathways earlier implicated in the human V(Y)9V delta 2 T cell response, as p38, JNK and PI3K/Akt but not ERK were activated in the A. gambiae 4a3B cell line. Additionally, both HMBPP and the downstream endogenous metabolite isopentenyl pyrophosphate displayed antioxidant effects by promoting cellular tolerance to hydrogen peroxide challenge. When provided in the mosquito blood meal, HMBPP induced temporal changes in the expression of several immune genes. In contrast to meso-diaminopimelic acid containing peptidoglycan, HMBPP induced expression of dual oxidase and nitric oxide synthase, two key determinants of Plasmodium infection. Furthermore, temporal fluctuations in midgut bacterial numbers were observed. The multifaceted effects observed in this study indicates that HMBPP is an important elicitor in common for both Plasmodium and gut bacteria in the mosquito.

  • 27.
    Lindstedt, Erik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Ghosh, Raju
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Metal-Free Synthesis of Aryl Ethers in Water2013Ingår i: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 15, nr 23, s. 6070-6073Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The first arylation of allylic and benzylic alcohols with diaryliodonium salts is reported. The reaction yields alkyl aryl ethers under mild and metal-free conditions. Phenols are arylated to diaryl ethers in good to excellent yields. The reaction employs diaryliodonium salts and sodium hydroxide in water at low temperature, and excess amounts of the coupling partners are avoided.

  • 28.
    Lindstedt, Erik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Reitti, Marcus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    One-Pot Synthesis of Unsymmetric Diaryliodonium Salts from Iodine and Arenes2017Ingår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 82, nr 22, s. 11909-11914Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The first synthesis of unsymmetric diaryliodonium salts directly from iodine and arenes is presented. The methodology provides diaryliodonium salts with the trimethoxyphenyl (TMP) moiety as dummy group. The protocol avoids the customary use of iodoarenes, which can be both expensive and toxic. Excess reagents are not required, and the reactions are performed under mild conditions. O-Arylations with these TMP salts were demonstrated to be highly chemoselective.

  • 29.
    Lindstedt, Erik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Stridfeldt, Elin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Mild Synthesis of Sterically Congested Alkyl Aryl Ethers2016Ingår i: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 18, nr 17, s. 4234-4237Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An efficient and transition-metal-free method is presented to access tertiary alkyl aryl ethers by arylation of tertiary alcohols with ortho-substituted diaryliodonium salts. The scope covers cyclic and acyclic aliphatic, benzylic, allylic, and propargylic tertiary alcohols as well as primary and secondary fluorinated alcohols. The methodology gives access to alkyl aryl ethers of previously unprecedented steric congestion. Furthermore, the versatility of the developed procedure was demonstrated by arylation of the pro-drug mestranol.

  • 30.
    Lindström, Ulf M.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Somfai, Peter
    Microwave-assisted aminolysis of vinylepoxides1999Ingår i: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 40, nr 52, s. 9273-9276Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Di- and trisubstituted vinyl epoxides in NH4OH were subjected to microwave irradn. affording the corresponding vicinal amino alcs. in high yields. The reaction is stereospecific and highly regioselective for addn. at the allylic carbon. [on SciFinder(R)]

  • 31.
    Malmgren, Joel
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Nagendiran, Anuja
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Tai, Cheuk-Wai
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Bäckvall, Jan-Erling
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    C-2 Selective Arylation of Indoles with Heterogeneous Nanopalladium and Diaryliodonium Salts2014Ingår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 20, nr 42, s. 13531-13535Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A simple and efficient method to prepare synthetically useful 2-arylindoles is presented, using a heterogeneous Pd catalyst and diaryliodonium salts in water under mild conditions. A remarkably low leaching of metal catalyst was observed under the applied conditions. The developed protocol is highly C-2 selective and tolerates structural variations both in the indole and in the diaryliodonium salt. Arylations of both NH indoles and N-protected indoles with ortho-substituted, electron-rich, electron-deficient, or halogenated diaryliodonium salts were achieved to give the desired products in high to excellent isolated yields within 6 to 15 h at room temperature or 40 °C.

  • 32.
    Malmgren, Joel
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Santoro, Stefano
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Jalalian, Nazli
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Himo, Fahmi
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Arylation with Unsymmetrical Diaryliodonium Salts: A Chemoselectivity Study2013Ingår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 19, nr 31, s. 10334-10342Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phenols, anilines, and malonates have been arylated under metal-free conditions with twelve aryl(phenyl)iodonium salts in a systematic chemoselectivity study. A new “anti-ortho effect” has been identified in the arylation of malonates. Several “dummy groups” have been found that give complete chemoselectivity in the transfer of the phenyl moiety, irrespective of the nucleophile. An aryl exchange in the diaryliodonium salts has been observed under certain arylation conditions. DFT calculations have been performed to investigate the reaction mechanism and to elucidate the origins of the observed selectivities. These results are expected to facilitate the design of chiral diaryliodonium salts and the development of catalytic arylation reactions that are based on these sustainable and metal-free reagents.

  • 33.
    Merritt, Eleanor A.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Carneiro, Vania M.T.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Silva Jr., Luiz F.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Facile synthesis of Koser's reagent and derivatives from iodine or aryl iodides2010Ingår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 75, nr 21, s. 7416-7419Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The first one-pot synthesis of neutral and electron-rich [hydroxy(tosyloxy)iodo]arenes (HTIBs) from iodine and arenes is presented, thereby avoiding the need for expensive iodine(III) precursors. A large set of HTIBs, including a polyfluorinated analogue, can be obtained from the corresponding aryl iodide under the same conditions. The reaction proceeds under mild conditions, without excess reagents, and is fast and high-yielding. Together, the two presented routes give access to a wide range of HTIBs, which are useful reagents in a variety of synthetic transformations.

  • 34.
    Merritt, Eleanor A.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Malmgren, Joel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Klinke, Felix J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Synthesis of diaryliodonium triflates using environmentally benign oxidizing agents2009Ingår i: Synlett: Accounts and Rapid Communications in Synthetic Organic Chemistry, ISSN 0936-5214, E-ISSN 1437-2096, nr 14, s. 2277-2280Artikel i tidskrift (Refereegranskat)
  • 35.
    Merritt, Eleanor A.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Diaryliodonium salts: A journey from obscurity to fame2009Ingår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 48, nr 48, s. 9052-9070Artikel, forskningsöversikt (Refereegranskat)
    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.

  • 36.
    Merritt, Eleanor A.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Diaryliodoniumsalze - aus dem Nichts ins Rampenlicht2009Ingår i: Angewandte Chemie, ISSN 1521-3757, Vol. 121, nr 48, s. 9214-9234Artikel, forskningsöversikt (Refereegranskat)
    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.

  • 37.
    Merritt, Eleanor A.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Synthesis of a range of iodine(III) compounds directly from iodoarenes2011Ingår i: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, nr 20-21, s. 3690-3694Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The first direct synthesis of an alkynyl(phenyl)iodonium salt from iodobenzene and an unprotected alkyne is described. The synthesis of the corresponding alkenyl(phenyl)iodonium salt is achieved from the TMS-alkyne, simply by means of changing the solvent. The one-pot synthesis of 1-arylbenziodoxolones and other iodine(III) compounds from iodine(I) precursors is also presented.

  • 38.
    Merritt, Eleanor A.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    α-Functionalization of carbonyl compounds using hypervalent iodine reagents2011Ingår i: Synthesis (Stuttgart), ISSN 0039-7881, E-ISSN 1437-210X, nr 4, s. 517-538Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    α-Functionalized carbonyl compounds are versatile intermediates in organic synthesis. A broad range of both carbon and heteroatom substituents can be introduced into the α-position of carbonyl compounds using hypervalent iodine reagents. Herein we summarize the use of these environmentally benign reagents with particular emphasis on catalytic and asymmetric methodology developed over the past decade.

  • 39. Norrby, Per-Ola
    et al.
    Petersen, Tue B.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Bielawski, Marcin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    α-Arylation by Rearrangement: On the Reaction of Enolates with Diaryliodonium Salts2010Ingår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 16, nr 28, s. 8251-8254Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Surprising equilibration: A new mechanism for the title reaction is supported by DFT calculations and experimental observations. The CI and OI intermediates are isoenergetic and equilibrate quickly. Thus, any chiral information induced in the initial complex will be destroyed. In the final CC bond-forming step, a [2,3]-rearrangement from the OI bonded intermediate is slightly preferred over the [1,2]-elimination from the CI bonded isomer (see scheme).

  • 40.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi. Stellenbosch University, South Africa.
    Arylation with Diaryliodonium Salts2016Ingår i: Hypervalent Iodine Chemistry / [ed] Thomas Wirth, Springer, 2016, s. 135-166Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    This chapter focuses on recent developments in metal-free and metal-catalyzed arylations with diaryliodonium salts (diaryl-λ3-iodanes). Synthetic routes to diaryliodonium salts are briefly described, and chemoselectivity trends with unsymmetric iodonium salts are discussed.

  • 41.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Fast, efficient and high-yielding routes to diaryliodonium salts2009Ingår i: European Symposium on Organic Chemistry (ESOC 16), Prague, Czech Republic, 2009, 2009Konferensbidrag (Övrigt vetenskapligt)
  • 42.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Fast, efficient and high-yielding routes to diaryliodonium salts2009Ingår i: 44th EUCHEM Conference on Stereochemistry, Bürgenstock, Switzerland, May, 2009, 2009Konferensbidrag (Övrigt vetenskapligt)
  • 43.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Fast, efficient and high-yielding routes to diaryliodonium salts2009Ingår i: XVIII EuCheMS Conference on Organometallic Chemistry, Gothenburg, Sweden, 2009, 2009Konferensbidrag (Övrigt vetenskapligt)
  • 44.
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Fast, efficient and high-yielding routes to diaryliodonium salts2009Ingår i: EUCHEMS Young Investigator Workshop, Liblice, Czech Republic, 2009, 2009Konferensbidrag (Övrigt vetenskapligt)
  • 45.
    Olofsson, Berit
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Aggarwal, Varinder K.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Enantioselective alfa-Arylation of Ketones: Application to the Synthesis of (–)-Epibatidine2006Ingår i: Sterochemistry, Bürgenstock, Switzerland, 2006Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 46.
    Olofsson, Berit
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Aggarwal, Varinder K.
    Bristol University, UK.
    Enantioselective alfa-Arylation of Ketones: Application to the Synthesis of (–)-Epibatidine2006Ingår i: Organikerdagarna, Kalmar, Sweden, 2006, s. Le21, P47-Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    The enantioselective introduction of electrophiles alfa to carbonyl compounds occupies a central position in asymmetric synthesis. Although asymmetric alkylations have been well developed, high enantioselectivity in α-arylation of ketones has only been achieved in a limited number of cases.

    We have developed a direct arylation reaction of cyclohexanones, employing diaryl iodonium(III) salts as electrophiles. The reaction was made enantioselective by the use of a chiral base, resulting in 2,4-substituted cyclohexanones in high yields and with high enantiomeric excesses and diastereoselectivities.

    This methodology was applied in a short, enantioselective synthesis of (–)-Epibatidine, an alkaloid recently isolated from the Ecuadorian poison frog Epipedobates tricolor. The synthesis was accomplished in 6 steps and 31% overall yield, thus providing the shortest and most efficient asymmetric route to this important compound to date.

  • 47.
    Olofsson, Berit
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Aggarwal, Varinder K.
    Bristol University, UK.
    Synthesis of Novel Heteroaryl Iodonium Salts and Enantioselective a-Arylation of Cyclohexanones2006Ingår i: 2nd Int. Conference on Hypervalent Iodine, 2006Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    We have developed a direct arylation reaction of cyclohexanones employing diaryl iodonium(Ill) salts as electrophiles. The

    reaction was made enantiosilective by the use of a chiral base, resultinginZ,4-disubstituted cyclohexanones in high yields and with high enantiomeric excesses and diastereoselectivities. Novel heteroaryl iodonium salts were subsequently synthesized and employed in the coupling to variously substituted cyclohexanones.

  • 48.
    Olofsson, Berit
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Bogár, Krisztián
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Fransson, Ann-Britt L
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Bäckvall, Jan-Erling
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Divergent asymmetric synthesis of 3,5-disubstituted piperidines.2006Ingår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 71, nr 21, s. 8256-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A divergent synthesis of various 3,5-dioxygenated piperidines with interesting pharmacological properties is described. A mixture of the achiral cis- and racemic trans-3,5-piperidine diol could be efficiently obtained from N-benzylglycinate in five steps by the use of chemoenzymatic methods. In the subsequent enzyme- and Ru-catalyzed reaction, the rac/meso diol mixture was efficiently transformed to the cis-(3R,5S)-diacetate with excellent diastereoselectivity and in high yield. Further transformations of the cis-diacetate selectively delivered the cis-piperidine diol and the cis-(3R,5S)-hydroxy acetate. Alternatively, the DYKAT could be stopped at the monoacetate stage to give the trans-(3R,5R)-hydroxy acetate.

  • 49.
    Olofsson, Berit
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Somfai, Peter
    Organisk kemi, KTH.
    Vinylepoxides in Organic Synthesis2006Ingår i: Aziridines and Epoxides in Organic Synthesis, Wiley-VCH: Weinheim , 2006, s. 315-347Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Vinylepoxides have become important intermediates in organic synthesis. The main reason for this is the development of selective methods for their subsequent transformations. As vinylepoxides are a special type of allylic electrophiles, it is necessary to control both the regioselectivity and the diastereoselectivity in their reactions with nucleophiles. The practical usefulness of vinylepoxides in synthesis will, however, always be dictated by their availability. Several methods for the asymmetric preparation of vinyloxiranes have been developed and it can be expected that the use of these compounds in organic synthesis will increase. This chapter starts with a discussion of the available techniques for preparing vinylepoxides, with emphasis on asymmetric methods. In the second part various transformations of vinylepoxides are summarized.

  • 50.
    Pace, Vittorio
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi. University of Vienna, Austria.
    Holzer, Wolfgang
    Olofsson, Berit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Increasing the Reactivity of Amides towards Organometallic Reagents: An Overview2014Ingår i: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 356, nr 18, s. 3697-3736Artikel, forskningsöversikt (Refereegranskat)
    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.

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