Asymmetric Organocatalysis with Novel Chiral Thiourea Derivatives: Bifunctional Catalysts for the Strecker and Nitro‐Michael Reactions

Abstract

Abstract Novel bifunctional organocatalysts bearing both a thiourea moiety and an imidazole group on a chiral scaffold were synthesized and applied to the Strecker synthesis and nitro‐Michael reaction. The addition of acetone to nitroolefins in the presence of these novel bifunctional organocatalysts gave enantioselectivities (up to 87 % ee ) that are superior to those generated by the proline and/or homo‐proline tetrazole catalysts described in the literature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)