DMSO/<i>t</i>-BuONa/O₂-Mediated Aerobic Dehydrogenation of Saturated <i>N</i>-Heterocycles

Abstract

Aromatic <i>N</i>-heterocycles such as quinolines, isoquinolines, and indolines are synthesized via sodium <i>tert</i>-butoxide-promoted oxidative dehydrogenation of the saturated heterocycles in DMSO solution. This reaction proceeds under mild reaction conditions and has a good functional group tolerance. Mechanistic studies suggest a radical pathway involving hydrogen abstraction of dimsyl radicals from the N-H bond or α-C-H of the substrates and subsequent oxidation of the nitrogen or α-aminoalkyl radicals.