P(NMe₂)₃-Mediated Domino Cyclization/Functionalization of Dicyanoalkenes

Abstract A P(NMe₂)₃-mediated domino reaction between dicyanoalkenes and benzoylformates has been developed. By switching between isatin- and tetralone-derived dicyanoalkenes, the protocol divergently furnishes either spirocyclopropyl oxindoles or α-functionalized dicyanoalkenes in up to 99% yield under mild conditions. Gram-scale experiments and a broad substrate scope highlight the synthetic utility of the transformation.