Control of chemoselectivity in asymmetric tandem reactions: Direct synthesis of chiral amines bearing nonadjacent stereocenters.

This paper describes the mechanistic insight-guided development of a catalyst system, employing a phenolic proton donor catalyst in addition to a cinchonium-derived phase-transfer catalyst, to control the chemoselectivity of two distinct intermediates, thereby enabling the desired asymmetric tandem conjugate addition-protonation pathway to dominate over a number of side-reaction pathways to provide a synthetic approach for the direct generation of optically active amines bearing two nonadjacent stereocenters.