Dynamic Kinetic Resolution of α-Trifluoromethyl Hemiaminals without α-Hydrogen via NHC-Catalyzed O-Acylation.


Gao YY(1)(2), Zhang CL(1), Dai L(1)(2), Han YF(1)(2), Ye S(1)(2).
Author information:
(1)Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
(2)University of Chinese Academy of Sciences, Beijing 100049, China.


Following the well-recognized dynamic kinetic resolution (DKR) of hemiaminals with α-hydrogen under lipase and chiral DMAP catalysis, the unprecedented DKR of hemiaminals without α-hydrogen was developed via N-heterocyclic carbene catalyzed O-acylation of 3-hydroxy-3-trifluoromethylbenzosultams. The racemic hemiaminals without α-hydrogen were effectively racemized and differentiated by chiral NHCs under basic conditions. The resulting esters were obtained in high yields with good to high enantioselectivities.