A catalyst that plays multiple roles:: Asymmetric synthesis of β-substituted aspartic acid derivatives through a four-stage, one-pot procedure

[GRAPHICS] e report a new method for the catalytic, asymmetric synthesis of P-substituted aspartic acid derivatives in which the nucleophilic catalyst serves up to four discrete roles in a one-pot procedure: catalytic dehydrohalogenation of acid chlorides to form ketenes; catalytic dehydrohalogenation of alpha-chloroamines to form the corresponding imines; catalyzed [2 + 2]-cycloaddition to produce intermediate acyl beta-lactams; and finally, nucleophilic ring opening to afford optically enriched beta-substituted aspartic acids in high en antioselectivity and diastereoselectivity.