Reaction of ethynylferrocene with arenesulphenyl chlorides

Abstract

The reaction of ethynylferrocene with arenesulphenyl chlorides [ArSCl; Ar = Ph, p-ClC₆H₄, p-MeC₆H₄, p-MeOC₆H₄, p-NO₂C₆H₄, or 2,4-(NO₂)₂C₆H₃] follows an unusual pathway; the main outcome is substitution of the acetylenic proton, rather than electrophilic addition to the triple bond. The following compounds were isolated and identified: FcCCSAr, FcCClCHSAr, and FcCClCH₂ or FcCOCH₃(Fc = ferrocenyl), depending on the reaction conditions. A mechanistic scheme is proposed.