Electrochemical Strain-Release Difunctionalization of Azabicyclo-[1.1.0]butanes with Nitroarenes

Direct aniline installation onto azabicyclo[1.1.0]butanes (ABBs) via polar strain release has remained challenging due to competitive electrophile-aniline coupling under polar conditions. We report an electrochemical platform that overcomes this limitation through controlled electron transfer using nitroarenes as aniline surrogates. Cathodic reduction of N-activated ABBs generates C3-centered radicals, while concurrent nitroarene reduction produces nitroso intermediates. Radical addition followed by electrochemical N-O bond cleavage delivers aniline-functionalized azetidines in a single operation. The method operates under mild conditions with broad functional-group tolerance, accommodating complex and synthetically valuable sulfonyl and acyl groups and diverse nitroarenes. By leveraging electrochemistry to control chemoselectivity and eliminate stoichiometric reductants, this method enables difunctionalization of azabicyclo[1.1.0]butanes to furnish aniline-functionalized azetidines bearing various N-sulfonyl and acyl groups, inaccessible via existing strain-release approaches.