Synthesis of [beta]-Boryl-[alpha]-Aminosilanes by Copper-Catalyzed Aminoboration of Vinylsilanes

A copper-catalyzed regioselective and stereospecific aminoboration of vinylsilanes with bis(pinacolato)diboron (pinB-Bpin) and hydroxylamines has been developed. In the presence of a CuCl/MeO-dppbz catalyst, the boryl group and amino group are incorporated at the [beta] position and [alpha] position, respectively, and the corresponding [beta]-boryl-[alpha]-aminosilanes are obtained with good diastereoselectivity. The boryl group is a good latent functional group, and subsequent manipulations provide a variety of [beta]-functionalized [alpha]-aminosilanes of great potential in medicinal chemistry. Additionally, preliminary application to asymmetric catalysis is also described.