The Asymmetric Piers Hydrosilylation

Article abstract of DOI:10.1021/jacs.6b03443

An axially chiral, cyclic borane decorated with just one C₆F₅ group at the boron atom promotes the highly enantioselective hydrosilylation of acetophenone derivatives without assistance of an additional Lewis base (up to 99% ee). The reaction is an unprecedented asymmetric variant of Piers' B(C₆F₅)₃-catalyzed carbonyl hydrosilylation. The steric congestion imparted by the 3,3′-disubstituted binaphthyl backbone of the borane catalyst as well as the use of reactive trihydrosilanes as reducing agents are keys to success.