Synthesis of ketones from iodoalkenes, carbon monoxide and 9-alkyl-9-borabicyclo[3.3.1]nonane derivatives via a radical cyclization and palladium-catalysed carbonylative cross-coupling sequence

Abstract

Under irradiation (tungsten lamp), the palladium-catalysed three-component cross-coupling reaction between iodoalkenes such as 6-iodo-1-hexene or their derivatives, carbon monoxide (1 atm) and 9-alkyl- or 9-aryl-9-BBN derivatives (9-BBN = 9-borabicyclo[3.3.1]nonane) produces unsymmetrical ketones in moderate to high yields; the oxidative addition of iodoalkenes to a palladium(0) complex proceeds via a radical process, thus allowing cyclization of the iodoalkenes to five-membered rings prior to the couplings with carbon monoxide and boron reagents.