Cobalt(II)-catalyzed asymmetric hydrosilylation of simple ketones using dipyridylphosphine ligands in air

摘要

In the presence of PhSiH_3 as the hydride donor, catalytic amounts of non-racemic dipyridylphosphine and an easy-to-handle cobalt salt Co(OAc)_2·4H_2O formed in situ an effective catalyst system for the asymmetric reduction of a diverse range of aryl alkyl ketones with moderate-to-excellent enantioselectivities (up to 96% ee). This approach tolerated the handling of both catalyst and reactants under air without special precautions.