Straightforward chemoselective access to unsymmetrical dithioacetals through a thiosulfonate homologation-nucleophilic substitution sequence

Abstract

A sequential C1-homologation–nucleophilic substitution tactic is presented for the preparation of rare unsymmetrical dithioacetals. The judicious selection of thiosulfonates as convenient sulfur electrophilic sources – upon the homologation event conducted on an intermediate α-halothioether – guarantees the release of the non-reactive sulfonate group, thus enabling the subsequent nucleophilic displacement with an external added thiol [(hetero)aromatic and/or aliphatic]. Uniform high yields and excellent chemocontrol were deduced during the extensive scope study, thus documenting the versatility of the direct technique for the preparation of these unique and manipulable materials.