Synthesis of 1,3-benzothiazines by intramolecular dehydrogenative C–S cross-coupling in a flow electrolysis cell

Abstract

Dehydrogenative cyclization of thioamides is an attractive approach for the synthesis of S -heterocycles. Reported herein is an electrochemical dehydrogenative cyclization reaction of N -benzyl thioamides in a flow electrolysis cell. The continuous-flow electrosynthesis has addressed the limitations associated with previously reported me thods for the cyclization of alkylthioamides and provide a transition metal- and oxidizing reagent-free access to various functionalized 1,3-benzothiazines in good yields.