In(OTf)3-catalyzed synthesis of 4-thiocyanotetrahydropyrans via a three-component reaction

A three-component coupling of aldehydes, homoallylic alcohols and ammonium thiocyanate is achieved in the presence of 10 mol % of In(OTf)3 in refluxing dichloromethane to produce 4-thiocyanotetrahydropyrans in excellent yields with all cis-selectivity. This method is simple, selective and convenient for introducing an SCN group onto a tetrahydropyran ring.