The construction of benzimidazo[2,1-]isoquinolin-6(5)-ones from -methacryloyl-2-phenylbenzoimidazoles through radical strategies.

Benzimidazo[2,1-]isoquinolin-6(5)-one constitutes a structurally unique class of tetracyclic N-heterocycles that are found throughout a myriad of biologically active natural products, pharmaceutical compounds, and functional materials. Various synthetic routes for the preparation of benzimidazo[2,1-]isoquinolin-6(5)-ones have been reported. In particular, the use of -methacryloyl-2-phenylbenzoimidazoles to construct benzimidazo[2,1-]isoquinolin-6(5)-ones through various radical strategies have attracted widespread attention due to the versatility and simple preparation of raw materials, as well as the step-economy and mild reaction conditions. Using representative examples, we highlight significant progress in the synthesis of benzimidazo[2,1-]isoquinolin-6(5)-ones, including the selection of the catalytic system, substrate scope, mechanistic understanding, and applications. The contents of this review focus on the development of -, -, -, and -centered radical addition-intramolecular cyclization strategies.