Low-Pressure Radical 11C-Aminocarbonylation of Alkyl Iodides through Thermal Initiation.

A radical 11C-aminocarbonylation protocol characterized by excellent substrate compatibility was developed to transform alkyl iodides into 11C-labelled amides, including the 11β-HSD1 inhibitor [ carbonyl-11C]adamantan-1-yl(piperidin-1-yl)methanone. This protocol serves as a complementary extension of palladium-mediated 11C-aminocarbonylation, which is limited to the preparation of 11C-labelled compounds lacking beta-hydrogen atoms. The use of AIBN as a radical initiator and a low-pressure xenon-[11C]CO delivery unit represents a simple and convenient alternative to previous radical 11C-carbonylation methodologies burdened with the need for a proprietary high pressure reactor connected to a light source. [ABSTRACT FROM AUTHOR]