Chiral Magnesium Bis(sulfonamide) Complexes as Catalysts for the Merged Enolization and Enantioselective Amination of N-Acyloxazolidinones. A Catalytic Approach to the Synthesis of Arylglycines

There is considerable interest in the development of catalyzed enantioselective enolate-electrophile bond constructions to complement existing procedures which typically employ stoichiometric chiral controllers. In the design of these catalytic processes it would be highly desirable to merge the enolization event with the desired enantioselective bond construction. Catalyzedâ-ketoester conjugate additions, 2 isocyanoacetic ester aldol reactions, 3 and nitro aldol reactions 4 are among the few examples that meet this design criterion. The purpose of this Communication is to disclose a chiral metal complex that will mediate the enolization and enantioselective electrophilic amination (El(+) ) BocNdNBoc) of aryl-substituted carboximides (eq 1) that possess a considerably lower predisposition toward enolization than the substrates employed in those studies cited above. 2-4