N-Heterocyciic Carbene Catalyzed Asymmetric Hydration: Direct Synthesis of α-Protio and α-Deuterio α-Chloro and α-Fluoro Carboxylic Acids

摘要

The catalytic asymmetric synthesis of α-halo carbonyl derivatives has received considerable attention in recent years. Approaches to accessing these valuable synthons currently rely on the asymmetric generation of the α-halo aldehyde or ester and their subsequent manipulation. We have previously shown that a,a-dichloro aldehydes in the presence of a chiral N-heterocyclic carbene (NHC) and phenol can yield the respective α-chloro aryl ester in good yields and ee's.