One‐Pot Synthesis of Novel Enantiomerically Pure and Racemic 4‐Ferrocenyl‐β‐lactams and Their Reactivity in Acidic Media

Abstract

Abstract A series of 4‐ferrocenyl‐ and 4‐[( S Fc )‐2‐( p ‐tolylsulfanyl)ferrocenyl]‐β‐lactams has been synthesized in good yields by a one‐pot reaction of achiral and planar‐chiral ferrocenylimines with substituted acetic acids. The acid‐induced stereoconvergent transformation of cis ‐ and trans ‐4‐ferrocenyl‐β‐lactams into ( Z )‐α,β‐unsaturated amides by protonation, N–C‐4 cleavage and subsequent exo ‐H elimination and the lack of reaction of the ortho ‐ S ‐tolylsulfanyl analogs are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)