Bifunctional Reagents for Photochemical Synthesis
Jia‐Yao Feng, Mingqi Yang, Honglin Wu, Ying Tong, Xi‐Ni Luo, Shiqing Zhang, Rongnan Yi, Jun‐Qi Zhang, Yiping Ruan, Wen‐Ting Wei
Abstract
Bifunctional reagents in photochemistry integrate radical activation sites with coupling modules within a single molecular framework, enabling precise construction of sophisticated moleculars. This review systematically summarizes recent advancements and reaction mechanisms of these reagents in photocatalysis regulated by energy transfer or photoinduced electron transfer. It emphasizes how kinetic matching and electronic modulation achieve selective activation of radical precursors. Cutting‐edge developments, including diverse metal‐based and metal‐free systems, and innovative mechanisms like strain‐release and proton‐coupled electron transfer, have expanded complex molecular synthesis. The review categorizes progress based on active sites and reaction modes into four classes: radical precursor‐radical precursor, radical precursor‐nucleophile, radical precursor‐electrophile, and radical precursor‐radical acceptor. Subclassifications are defined by the central atom type of radicals and transformation patterns, revealing intrinsic correlations between reagent parameters (e.g., bond dissociation energy, electronic distribution, steric effects) and reaction pathways. This review aims to establish precise yet universal methodologies for guiding drug synthesis and functional material development.