Remote asymmetric conjugate addition catalyzed by a bifunctional spiro-pyrrolidine-derived thiourea catalyst

Abstract

A novel spiro-pyrrolidine (SPD)-derived bifunctional thiourea catalyst has been developed, enabling the development of a stereoselective conjugate addition of furfurals to β,γ-unsaturated α-ketoesters. The reaction represents an example of asymmetric trienamine catalysis in the benzylic C–H functionalization of 5-benzylfurfurals, and the rigid spirocyclic framework of the catalyst is proven to be essential for a highly enantioselective transformation.