Synthesis of γ-, δ-, and ε-Lactams by Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)iminoesters

Highly enantiomerically enriched γ- and δ-lactams have been prepared by a simple and very efficient procedure that involves the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)iminoesters followed by desulfinylation of the nitrogen atom and spontaneous cyclization to the desired lactams during the basic workup procedure. Five- and six-membered ring lactams bearing aromatic, heteroaromatic, and aliphatic substituents have been obtained in very high yields and ee’s up to >99%. A slight modification of the procedure also allowed the preparation of ε-lactams in good yields and very high enantioselectivities. Both enantiomers of the final lactams could be prepared with equal efficiency by changing the absolute configuration of the sulfinyl chiral auxiliary

Rapid synthesis of 1,3,4,4-tetrasubstituted beta-lactams from methyleneaziridines using a four-component reaction

2-Methyleneaziridines can be transformed into a variety of 1,3,4,4-tetrasubstituted beta-lactams in moderate to good yields (46-63%) via a "one-pot" process that brings together four components with the formation of three new intermolecular carbon-carbon bonds