Electrochemical synthesis of spirocyclic morpholines and tetrahydrofurans via an oxidative dearomatisation strategy

Abstract

In search for developing synthetic routes towards spirocyclic morpholines and tetrahydrofurans, we developed a convenient electrochemical protocol for dearomatization of methoxy-benzene derivatives. The electrochemical oxidation of the electron-rich benzene ring followed by intramolecular capture of the cation-radical intermediates accessed desired spirocyclic products. The scope of the reaction demonstrated tolerance of various functional groups such as alkenes, alcohols, bromines, fluorines, trifuoromethyl, cyano, ester and amides with reaction yield varying between 46-91%.