Iron (II)-Catalysed Synthesis of alfa-aryl and alfa-alkylthioacetylamides

Abstract

The potential of iron(II)-catalysed reactions the synthesis of α-aryl and α-alkyl thioacetylamides from acetylthiomides is reported. Iron(II) ion efficiently catalyses reactions of iodobenzene 1a or 1-iodoadamantane 1b with N-thioacetylmorpholine anion 2 in DMSO. Ferrous bromide amounts in the 0.6–1.6 mol% range are large enough to reach yields of 86% of α-phenil-N-thioacetylmorpholine 3a and 65% of α-(1-adamanthyl)-N-thioacetyl-morpholine 3b. These catalytic reactions are more easily handled than photoinduced reactions, and provide a useful route to the synthesis of α-aryl and α-alkyl thioacetylamides from acetylthiomides without the need for special photochemical devices. A possible reaction pathway is suggested for the iron(II)-catalysed process involving iron-thioamide enolate complexes.