Selenocyanation using a combined reagent of triphenylphosphine and selenocyanogen. A new and simple synthesis of alkyl selenocyanates and symmetrical alkyl diselenides from alcohols

A novel reagent Ph3SeCN)2, easily prepared by adding an equimolar amount of tri-phenylphosphine to selenocyanogen solution in methylene chloride and tetrahydrofuran reacts below −60° with primary alcohols to produce directly the corresponding alkyl selenocyanates and alkyl diselenides in good yields. With secondary alcohols mixtures of selenocyanates and isoselenocyanates are obtained, while tertiary alcohols fail to react with the reagent.