Copper-catalyzed carboxylation of alkylboranes with carbon dioxide: formal reductive carboxylation of terminal alkenes.

Carboxylation of alkylboron compounds (alkyl-9-BBN) with CO(2) proceeded in the presence of catalytic amounts of CuOAc/1,10-phenanthroline and a stoichiometric amount of KO(t)Bu. The alkylboranes are easily and widely available through the alkene hydroboration, and thus the overall process represents a reductive carboxylation of alkenes with CO(2). The broad functional group compatibility and the inexpensiveness of the Cu/1,10-phenathoroline catalyst system are attractive features of this protocol.