Phosphorous acid–assisted electrochemical α-tetrahydrofuranylation of sulfonamides and amides

Abstract

Tetrahydrofuran rings are present in a wide variety of biologically active molecules, which highlights the importance of developing a mild, convenient method for synthesizing compounds bearing these rings. Herein, we report an electrochemical protocol for phosphorous acid–assisted synthesis of hemiaminal ethers by means of α-C(sp³)–H/N–H cross-coupling reactions between tetrahydrofuran and sulfonamides or amides. This protocol does not require a chemical oxidant and can be performed at room temperature. Various sulfonamides and amides were suitable substrates, giving moderate to high yields of the desired cross-coupling products.