Recent Advances in Combining Photo- and N-Heterocycle Nitrenium Catalysis

Abstract N-Heterocyclic nitreniums (NHNs) are isoelectronic and isostructural analogues of N-heterocyclic carbenes (NHCs). Unlike NHCs, NHNs are much less developed. While a comprehensive understanding of NHN reactivity remains elusive, recent advancements have demonstrated their utility as Lewis acid catalysts, photoreductants, and photooxidants, leading to several reaction patterns. In this short review, we focus on the applications of NHNs in photoredox reactions. We also discuss the mechanisms behind these transformations and outline future research directions. 1 Introduction 2 Application of N-Heterocyclic Nitreniums as Photoreductants 3 Application of N-Heterocyclic Nitreniums to Facilitate Photohomolysis 4 Application of N-Heterocyclic Nitreniums as Photooxidants 5 Conclusion