Nucleophilic organocatalysis involving radical intermediates

The field of nucleophilic organocatalysis has garnered enormous interest and utility in the past two decades. Additionally, radical chemistry, mainly driven by the research progress in photocatalysis and electrocatalysis, has regained extensive attention. The unique reactivity of free radicals, which is different that of from closed-shell species, provides a solution to issues in electron-pair-mechanism-based catalysis. In this review, we highlight the advances in single-electron nucleophilic organocatalysis. We have separated the review into amine, N-heterocyclic carbene (NHC) and phosphine sections according to the type of organocatalyst. The strategies for the generation of radical species and the formation of new bonds are emphasized in the discussions of specific reactions. The final section provides a brief outline of the relationships among different nucleophilic organocatalysis and the prospects for future development.