Compounds labelled with ¹¹C (β⁺, t_1/2 = 20.4 min) are used in positron emission tomography (PET), which is a quantitative non-invasive molecular imaging technique. It utilizes computerized reconstruction methods to produce time-resolved images of the radioactivity distribution in living subjects.

The feasibility of preparing [¹¹C]methyl iodide from [¹¹C]methane and iodine via a single pass through a non-thermal plasma reactor was explored. [¹¹C]Methyl iodide with a specific radioactivity of 412 ± 32 GBq/µmol was obtained in 13 ± 3% decay-corrected radiochemical yield within 6 min via catalytic hydrogenation of [¹¹C]carbon dioxide (24 GBq) and subsequent iodination, induced by electron impact.

Labelled ethyl-, propyl- and butyl iodide was synthesized, within 15 min, via palladium-mediated carbonylation using [¹¹C]carbon monoxide. The carbonylation products, labelled carboxylic acids, esters and aldehydes, were reduced to their corresponding alcohols and converted to alkyl iodides. [1-¹¹C]Ethyl iodide was obtained via palladium-mediated carbonylation of methyl iodide with a decay-corrected radiochemical yield of 55 ± 5%. [1-¹¹C]Propyl iodide and [1-¹¹C]butyl iodide were synthesized via the hydroformylation of ethene and propene with decay-corrected radiochemical yields of 58 ± 4% and 34 ± 2%, respectively. [1-¹¹C]Ethyl iodide was obtained with a specific radioactivity of 84 GBq/mmol from 10 GBq of [¹¹C]carbon monoxide. [1-¹¹C]Propyl iodide was synthesized with a specific radioactivity of 270 GBq/mmol from 12 GBq and [1-¹¹C]butyl iodide with 146 GBq/mmol from 8 GBq.

Palladium-mediated hydroxycarbonylation of acetylene was used in the synthesis of [1-¹¹C]acrylic acid. The labelled carboxylic acid was converted to its acid chloride and subsequently treated with amine to yield N-[carbonyl-¹¹C]benzylacrylamide. In an alternative method, [carbonyl-¹¹C]acrylamides were synthesized in decay-corrected radiochemical yields up to 81% via palladium-mediated carbonylative cross-coupling of vinyl halides and amines. Starting from 10 ± 0.5 GBq of [¹¹C]carbon monoxide, N-[carbonyl-¹¹C]benzylacrylamide was obtained in 4 min with a specific radioactivity of 330 ± 4 GBq/µmol.