Part I Development of Nucleophilic Acylation Catalysts Part II Chiral Brønsted Acid Catalyzed Enantioselective Alcoholysis

Chiral bicyclic amidines and isothioureas developed in our group have been showed as a new type of nucleophilic acyl transfer catalysts. Based on the previous achievement in our group, several aza-analogues and a 5,7-menbered ring bicyclic analogue of THTP were prepared. Its synthesis proved to be more laborious than that of the THTP analogue derivative, and the enantioselectivity was substantially lower. Based on the previous discovery in our group that 1,2,4-triazole anion, as an active acyl transfer catalyst, can promote aminolysis and transesterification of moderately activated or even unactivated esters, a systematic study of pyrazole derivatives in this transformation was demonstrated. Two types of derivatives with equal or better activity than pyrazole itself were identified. Based on our achievement in the Dynamic Kinetic Resolution: DKR) of azlactones via acyl transfer catalysis, a new method of DKR of azlactones catalyzed by chiral BrØnsted acid was developed, high enantioselectivity: 85-92% ee) were obtained for the aryl-substituted azlactones. It was the first time that chiral BrØnsted acid catalysis was applied to the enantioselective acylation reaction. The application of this new method was also applied to the kinetic resolution of oxazinones, modest enantioselectivity was obtained: s≤9)