In(OTf) 3 -catalyzed reorganization/cycloaddition of two imine units and subsequent modular assembly of acridinium photocatalysts.

Herein, we disclose a novel reorganization/cycloaddition between two imine units catalyzed by In(OTf) 3 Lewis acid that differs from the well-known [4 + 2] cycloaddition version via the Povarov reaction. By means of this unprecedented imine chemistry, a collection of synthetically useful dihydroacridines has been synthesized. Notably, the obtained products give rise to a series of structurally novel and fine-tuneable acridinium photocatalysts, offering a heuristic paradigm for synthesis and efficiently facilitating several encouraging dihydrogen coupling reactions.