ChemSusChem | 2021
Visible-light Catalyzed N-Radicals Enabled Cyclization of Alkenes for the Synthesis of five-Membered N-Heterocycles.
Abstract
Five-membered N -heterocycles play an important role in organic synthesis and material chemistry, as they are widespread through pharmaceutical molecules and natural products. Chemists have developed many synthetic strategies for constructing five-membered N -heterocycles from N -centered radicals, but the availability of mild and green methods for these transformations is still limited. The cyclization of visible-light-generated N -centered radicals with alkenes has emerged as a powerful tool to enable these chemical transformations in recent years. Through chosen representative examples, we outline the significant developments in this promising field, including the selection of catalysts, substrate scope, mechanistic understanding (especially density functional theory (DFT) calculations), and applications. The contents of this review are categorized by intramolecular cyclization and intermolecular N -centered radical addition/cyclization reactions.