Sustainable Cascades to Difluoroalkylated Polycyclic Imidazoles

We reported herein a visible light promoted difluoroalkylated cascade of imidazoles and alkenes to afford highly functionalized polycyclic imidazoles. This method features a direct radical cyclization of imidazoles with alkenes using BrCF2R as radical sources. The reaction conditions tolerate a wide range of substrate scope and afford the desired products with up to 95 % isolated yield under mild conditions. Radical-trapping and light-on/off experiments indicated a photocatalytic radical mechanism.

Automated summary

A visible light promoted difluoroalkylated cascade reaction of imidazoles and alkenes was reported, providing highly functionalized polycyclic imidazoles. The method allows for a direct radical cyclization of imidazoles with alkenes using BrCF2R as radical sources, with up to 95% isolated yield under mild conditions. Radical-trapping and light-on/off experiments suggested a photocatalytic radical mechanism.