Highly Chemoselective and Enantiospecific Suzuki-Miyaura Cross-Couplings of Benzylic Organoboronic Esters

The use of potassium carbonate in addition to silver oxide is shown to increase the enantiospecificity of the Suzuki-Miyaura cross-coupling reaction of chiral secondary benzylic boronic esters. From mechanistic studies, it is shown that the reaction is compatible with Mizoroki-Heck coupling partners, even when they are present in considerable excess. This unique chemoselectivity provides the opportunity to carry out sequential reactions.