Diastereodivergent chiral aldehyde catalysis for asymmetric 1,6-conjugated addition and Mannich reactions

摘要

Chiral aldehyde catalysis is a burgeoning strategy for the catalytic asymmetric α-functionalization of aminomethyl compounds. However, the reaction types are limited and to date include no examples of stereodivergent catalysis. In this work, we disclose two chiral aldehyde-catalysed diastereodivergent reactions: a 1,6-conjugate addition of amino acids to para-quinone methides and a bio-inspired Mannich reaction of pyridinylmethanamines and imines. Both the syn- and anti-products of these two reactions can be obtained in moderate to high yields, diastereo- and enantioselectivities. Four potential reaction models produced by DFT calculations are proposed to explain the observed stereoselective control. Our work shows that chiral aldehyde catalysis based on a?reversible imine formation principle is applicable for the α-functionalization of both amino acids and aryl methylamines, and holds potential to promote a range of asymmetric transformations diastereoselectively. Chiral aldehyde catalysis is a useful strategy in the catalytic asymmetric α-functionalization of amino methyl compounds but these reaction types are limited. Here, the authors report two chiral aldehyde-catalysed diastereodivergent reactions, namely, a 1,6-conjugate addition and a bio-inspired Mannich reaction.