Recent Advances on Light-Mediated Nitrene Transfer Reactions: An Emerging Area

Abstract

Nitrogen atoms are fundamental in biological systems and are widely found in approved drugs, natural products, and materials. Thus, catalytic methods for the C−N bond formation have attracted significant attention in synthetic chemistry. Among the toolbox, nitrene transfer reaction is one of the powerful protocols for the construction of N-incorporating frameworks with structural diversity. In this field, transition metal-catalyzed nitrene transfer reactions have been extensively explored using different types of precursors. On the other hand, photochemistry offers a sustainable protocol in synthetic chemistry, which has emerged as an eco-friendly catalytic method in nitrene chemistry, particularly, with the induction of visible light as the initiator in this area. In the last decade, a variety of visible-light-mediated synthetic transformations involving free nitrene species have been reported under mild reaction conditions. Thus, it is timely and highly desirable to summarize the advancements in this area. This review summarized the advances in photo-mediated nitrene transfer reactions from 1950s–2024, which is organized into two sections according to the protocols for the nitrene formation: (i) direct photolysis of diverse nitrene precursors and (ii) photocatalytic generation of free nitrenes. The detailed reaction mechanisms and synthetic potential are the main focus in this review article.