vic-Iodothiocyanates and iodoisothiocyanates. Part 8. Addition of iodine–thiocyanogen to alkenes under ionic and radical conditions

Abstract

Addition of iodine–thiocyanogen to alkenes in the dark proceeds by a regioselective ionic reaction to give mainly vic-iodoisothiocyanates, and under irradiation with u.v. light by a radical reaction to give mainly vic-iodothiocyanates. However, in the case of 1-methylene-4-t-butylcyclohexane even under irradiation by u.v. light, ionic addition of the reagent competes successfully with, and almost to the exclusion of, the radical pathway.