Asymmetric Counteranion-Directed Photoredox Catalysis (ACPC)

Achieving high enantioselectivity in photoredox transformations poses a formidable challenge in asymmetric catalysis, possibly because of the high energy of the activated radical (ion) intermediates. Very recently, our group unlocked a new general reactivity mode of IDPi catalysts. Pairing of cationic photocatalysts with IDPi counteranions delivers chiral photoredox catalyst systems. The confined chiral IDPi counteranion of the photocatalyst salt enables asymmetric [2+2] cross-cycloaddition of styrenes and cyclopropanations of olefins with unprecedented levels of enantioinduction. The general underlying concept of using these salts as catalysts in asymmetric photoredox transformations has been termed asymmetric counteranion-directed photoredox catalysis (ACPC), in reference to the previously established ACDC. ACPC may provide a potentially general solution to radical cation-based asymmetric photoredox catalysis. Current efforts are directed towards further exploring and extending the method.

Selected publications