Generalized Approach to Asymmetric Synthesis of -Substituted -Amino Acids Bearing CHF2, CBrF2, and CClF2 Groups

Currently, there is a great demand for the development of new methods for the preparation of fluorine containing compounds. However, biologically relevant molecules bearing fluoroalkyl groups other than CF3 still remain virtually unexplored. Herein, we report a simple approach for preparation of -amino acids derivatives containing CHF2, CBrF2, and CClF2 groups via addition reactions of the corresponding (Ss)-N-(tert-butanesulfinyl)-CXF2-acetaldimines and alkyl-acetate-derived enolates. The reactions occur with excellent diastereoselectivity of up to >99:1 providing a simple and reliable access to a type of biologically valuable derivatives.