A Novel Approach to Dihydropyrrolones from Iron-Substituted α,β-Unsaturated Imines and Organolithium and Grignard Reagents: Developments, Mechanisms and Stereoselective Syntheses

Abstract

Reactions of N-sulfonylimines, derived from Cp(CO)2Fe-substituted (Z)-enals and benzenesulfonamide, with Grignard or organolithium reagents furnish N-sulfonyldihydropyrrolones. When N-sulfinylimines and organometallic reagents are used, unprotected α,β-unsaturated γ-lactams are formed exclusively. Recent mechanistic studies and diastereoselective variations for the synthesis of chiral 5-substituted dihydropyrrolones from iron-substituted azadienes are discussed here.