Diastereoselective synthesis of CF3-dihydrobenzofurans by [4+1] annulation of in situ-generated CF3-o-quinone methides and sulfur ylides

An efficient and highly diastereoselective synthesis of CF3-dihydrobenzofurans by the reaction of in situ-generated CF3-oQMs in the presence of a base with sulphur ylides is put forward. The generality of the present developed method was well studied with diverse substrates to access the corresponding products in excellent yields. The highly reactive CF3-oQM has been utilized first time for the annulation reaction.