Nitrogen Substituent-Dependent Asymmetric Staudinger Reactions

Significance

While catalytic asymmetric synthesis of cis-β-lactams have been reported, the highly trans-selective version has yet to be realized. The use of the planar chiral catalyst with N-tosyl imines gave cis-products, while the use of N-triflyl imines afforded predominantly trans-products. The trans-products were obtained in good yields with excellent diastereo- and enantioselectivities. The utility of the resulting trans-β-lactams was shown by one-step conversion to useful compounds such as γ-amino alcohols, β-amino acids, and β-amino amides.