Herein we report the highly asymmetric aza-Michael reactions of alpha,beta-enones (2-enoylthiazoles) with metalated chiral oxazolidinones under different reaction conditions and for different substituents at the beta-position of the Michael acceptor. The reaction proceeds with complete diastereoselectivity to give exclusively one of the two diastereomers. The significance of the reaction is that no catalyst has been used; the steric requirements of the chiral Michael nucleophile drive the stereospecificity of the reaction and the reaction time is much less compared to the reported procedures. This methodology might be useful for an improved total synthesis of the highly cytotoxic peptides known as the tubulysins.