Heterogeneous and homogeneous chiral Cu(ii) catalysis in water: enantioselective boron conjugate additions to dienones and dienoesters

Abstract

It was proved that a judicious choice of counteranion played a prominent role in Cu(II) catalysis for enantioselective boron conjugate additions in water; the use of Cu(OH)₂ renders heterogeneous catalysis, whereas Cu(OAc)₂ renders homogeneous catalysis; cyclic dienones underwent a remarkable switch of regioselectivity between 1,4- and 1,6-modes of the additions through these catalyses.