Heterogeneous Thiocyanation of Benzylic Alcohols and Silyl and THP Ethers, and Deprotection of Silyl and THP-Ethers by [PCl3-n(SiO2)n] (Silphos)

A Simple, One-Pot and Phosphine-Free Procedure for Thiocyanation of Alcohols Using N-(p-toluenesulfonyl) Imidazole (TsIm)

An efficient, one -pot, phosphine-free thiocyanation of alcohols has been achieved utilising potassium thiocyanate and N-(p-toluene sulfonyl) imidazole (TsIm) as a coupling agent in the presence of triethylamine in anhydrous DMF at 70 °C. This method converts primary alcohols into the corresponding thiocyanates, without isomerisation to isothiocyanates, in good to excellent yields. A total of 17 thiocyananates were prepared, five of which are novel. Using one equivalent of KSCN, the method shows good selectivity in the thiocyanation of a primary alcohol in the presence of a secondary alcohol.