Beneficial Effect ofortho-Methoxy Groups in the Asymmetric Ring Opening ofmeso Epoxides with Silicon Tetrachloride Catalyzed by Chiralortho-Methoxyphenyldiazaphosphonamide Lewis Bases

Enantiomerically enriched chlorohydrins can be formed by desymmetrization of meso epoxides. Chiral aryl phosphonic amides such as 1 catalyze the ring opening of the epoxides by SiCl4 to yield the chlorohydrins with good yields (up to 95%) and ee values (up to >99% ee).