Ni/Photoredox Catalyzed Direct α-C–H Functionalization of Azacycle

Abstract

Allylic amines are commonly found in bioactive molecules, pharmaceutical reagents, and natural products. Herein, we report the first strategy of direct enantioselective α-C–H alkenylation of cyclic amine for the synthesis of α-alkenylated amines via Ni/photoredox dual catalysis. In this process, Ni halide and a photocatalyst were used to perform easier C–H activation, and the halogen radical generated from the Ni catalyst was used as a hydrogen atom transfer reagent cleave the strong azacycle C–H bond. Azacycle and alkenyl bromide were able to proceed with this cross-coupling reaction. Various kinds of chiral ligands were screened and reaction conditions were screened. Additionally, asymmetric alkenylation reaction optimization of azacycle was performed, and a mechanistic study was conducted. Lastly, we confirmed the substrate scope to demonstrate the versatility of this strategy.