Asymmetric Synthesis of Silicon-Stereogenic Silanes by Copper-Catalyzed Desymmetrizing Protoboration of Vinylsilanes.

The catalytic asymmetric creation of silicon-stereocenter silanes is a long-sought but far less developed topic, and only a handful of examples have been reported. Moreover, the construction of (more than) two stereocenters-containing chiral silanes is a more arduous task and remains unexploited. We herein report an unprecedented copper-catalyzed desymmetrizing protoboration of divinyl substituted silanes with bis(pinacolato)diboron (B 2 pin 2 ). This method allows facile preparation of an array of enantiomerically enriched boronate-substituted organosilanes bearing contiguous silicon- and carbon-stereocenters with exclusive regioselectivity and generally excellent diastereo- and enantioselectivity.