Extremely efficient hydroboration of ketones and aldehydes by copper carbene catalysis

Abstract

A readily available copper carbene complex, (IPr)CuOtBu, catalyses the hydroboration of ketones and aldehydes even at very low catalyst loadings (0.1 mol%), in some cases with turnover frequencies exceeding 6000 h⁻¹. Carbonyl reduction occurs selectivitily in the presence of other reducible functional groups including alkenes, nitriles, esters, and alkyl chlorides.