Formation and reactivity of thiirenium ions

Abstract

Evidence is reported that thiirenium ions are involved as intermediates in both the addition of benzenesulphenyl chloride to diarylacetylenes and in unimocular substitution reactions of β-phenylthiovinyl sulphonates. The thiirenium ion generated from 1,2-diphenyl-2-phenylthiovinyl 2,4,6-trinitrobenzenesulphonate undergoes nucleophilic attack by chloride ion both at the carbon atoms to give 1,2-diphenyl-2-phenylthiovinyl chloride and at the sulphur atom to give diphenylacetylene and benzenesulphonyl chloride which can be trapped by added scavengers.