Effect of chalcogenyl substituent on the course of allyl rearrangement at chalcogenation of 1,3-dichloropropene

Formation of 1,3-dichalcogenylpropene at the treatment of 1,3-dichloropropene with organic dichalcogenides in a redox system hydrazine hydrate–KOH is governed by the possibility of an allyl rearrangement. In the presence of bases this rearrangement proceeds via carbanion partially stabilized by the chalcogenyl substituent. The effectivity of the stabilization and consequently the probability of the rearrangement varies in the series of substituents PhS > BnS > PhSe. In the stage of the direct nucleophilic substitution of chlorine the anion PhSe ‒ possesses the highest activity.