Red-light-driven enantioselective Minisci-type addition to heteroarenes via recyclable semi-heterogeneous catalysis†

Abstract

Catalytic asymmetric transformations driven by red light, particularly those involving heterogeneous or semi-heterogeneous catalysis, remain unknown. Herein, the enantioselective red-light-catalysed Minisci-type addition of heteroarenes utilizing mesoporous graphitic carbon nitride (mpg-CN) as a recyclable semi-heterogeneous photocatalyst in the presence of chiral phosphoric acid, generating a series of functionalized chiral heteroarenes in high stereoselectivity (up to >19 : 1 dr, >99% ee), is disclosed. Notably, both the photocatalyst and chiral phosphoric acid can be recycled. The heterogeneous nature of mpg-CN enables easy recovery and recycling, demonstrating that no activity and stereoselectivity were lost after ten runs. These photoredox catalyzed reactions can also be conducted under sunlight irradiation and can successfully be applied to large scale synthesis, showing significant potential for industrial application.