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

[Image: see text] 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).