Straightforward chemoselective access to unsymmetrical dithioacetals through a thiosulfonate homologation-nucleophilic substitution sequence
作者:Laura Ielo、Veronica Pillari、Natalie Gajic、Wolfgang Holzer、Vittorio Pace
DOI:10.1039/d0cc04896h
日期:——
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]
It has been found that the reactions of sulfoxides bearing hydrogen(s) at the α-position (R1SOCHR2R3: R1 = alkyl or Ph; R2 = H, alkyl, or Ph; R3 = H or Me) with thiols (R4SH: R4 = alkyl or aryl) in the presence of the (diisopropylamino)magnesium reagent, generated in situ from the reaction of ethylmagnesium bromide and diisopropylamine, in diethyl ether gave unsymmetrical dithioacetals (R1SCR2R3SR4)