Carbene and Acid Cooperative Catalytic Reactions of Aldehydes and o-Hydroxybenzhydryl Amines for Highly Enantioselective Access to Dihydrocoumarins

• DOI: 10.1021/acs.orglett.7b02883
• Publication Date: 2017-10-25T15:47:40Z
• Authors: Xingkuan Chen; Runjiang Song; Yingguo Liu; Chong Yih Ooi; Zhichao Jin; Tingshun Zhu; Hongling Wang; Lin Hao; Yonggui Robin Chi
• Keywords: Brønsted–Lowry acid–base theory

A highly enantioselective method for quick access to dihydrocoumarins is reported. The reaction involves a cooperative catalytic process with carbene and in situ generated Brønsted acid as the catalysts. α-Chloro aldehyde readily available stable o-hydroxybenzhydryl amine substrates were used generate reactive azolium ester enolate ortho-quinone methide (o-QM) intermediates, respectively, form exceptionally high diastereo- enantioselectivities. products can be easily transformed valuable pharmaceuticals bioactive molecules.