Thiocyanogen does not react with simple alkynes under heterolytic conditions in benzene at 20-25°. Under homolytic conditions, addition occurs readily giving mixtures of E-and Z- dithiocyanatoalkenes with high E: Z ratios; prolonged treatment with excess reagent also leads to mixtures of the dithiocyanatoalkenes but usually with lower E: Z ratios. A radical- chain mechanism, involving preferential anti-addition of thiocyanogen in an initial ...
