Cerium(Ⅲ) triflate-catalyzed ring opening of epoxides

Abstract

A simple and efficient method has been developed for the regioselective ring opening of epoxides with amines using catalytic amounts of cerium(III) triflate. This method was applicable to a wide range of substrates and allowed for gram-scale synthesis. In the case of cyclohexene oxide, only one isomer with trans stereochemistry was formed. Aminolysis of styrene oxide with aniline provided the main product with attack at the benzyl position. Unfortunately, the reaction of styrene oxide with aliphatic amines was poorly regioselective. It was confirmed that this method can be applied to the efficient synthesis of bioactive substances such as vesamicol, benzovesamicol, tulobuterol, propranolol, and (±)-naftopidil.