Photoinitiated free radical carbonylation enhanced by photosensitizers

The enhancing effect of several photosensitizers in photoinitiated radical carbonylation is demonstrated and applied to accelerate the synthesis of compounds labeled with short-lived C-11. With the sensitizers, the synthesis of [carbonyl-C-11]esters and acids from alkyl iodides, [11C]carbon monoxide, alcohols, and water provided up to 75-85% decay-corrected radiochemical yields in 6-min reactions under mild conditions. Acetone was used as a sensitizer in preparing C-13-substituted 1,10-decanedicarboxylic acid from (C-13)carbon monoxide.