Selective copper-catalyzed allylic oxidations using a 1/1 ratio of cycloalkene and tert-butylperbenzoate

Abstract

With Cu(MeCN) 4BF 4 as catalyst and benzotrifluoride as solvent, the allylic oxidation of cyclohexene by tert-butyl perbenzoate was performed at room temperature in 75% yield without requiring an axcess of the olefin. The benzoyloxylation of other cycloalkenes in using such a substrate/perester ratio required additives such as DBU, DBN or DMAP, and often an increase of the reaction temperature.