Molecular-Geometry-Guided Photocatalytic Dearomative Cyclization to Bis-spirolactams from Bicyclo[1.1.0]butanes

Abstract Increased sp3 character and three-dimensionality in molecules have been associated with favorable pharmacokinetic outcomes. As a result, methods for creating rigid spiro centers via dearomatization of arenes have gained traction in recent years. While the existing spirocyclic space is dominated by “monospiro” skeletons, there exist significant gaps in strategies toward “bis-spiro” derivatives. Herein we describe a molecular-geometry-guided design of a class of bicyclo[1.1.0]butane substrates and their subsequent application strategy to access bis-spiro lactams via dearomative ipso cyclization relays.