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

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. [ABSTRACT FROM AUTHOR]