Copper(I)-Mediated 11C-Carboxylation of (Hetero)arylstannanes

A novel copper-mediated carboxylation strategy of aryl- and heteroaryl-stannanes is described. The method serves as a mild (i.e., 1 atm) carboxylation method using stable carbon dioxide and is transferable as a radiosynthetic approach for carbon-11-labeled aromatic and heteroaromatic carboxylic acids using sub-stoichiometric quantities of [ 11 C]CO 2 . The methodology was applied to the radiosynthesis of the retinoid X receptor agonist, [ 11 C]bexarotene, with a decay-corrected radiochemical yield of 32 ± 5% and molar activity of 38 ± 23 GBq/μmol ( n = 3).