Recent advances in Norrish-Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis

In recent years, the Norrish-Yang cyclization and related photoredox reactions of dicarbonyls have been extensively utilized in natural product synthesis. This review summarizes the latest advancements in these reactions for constructing terpenoids, alkaloids, and antibiotics. Through Norrish-Yang cyclization, dicarbonyls (e.g., 1,2-diketones and α-keto amides) can efficiently construct sterically hindered ring structures, which can further undergo ring-opening or rearrangement reaction to assemble complex molecular frameworks. Additionally, quinone photoredox reactions involving single-electron transfer (SET) processes provide novel strategies for the stereoselective synthesis of useful structures such as spiroketals. This review, drawing on examples from recently reported natural product syntheses, elaborates on reaction mechanisms, factors governing regioselectivity and stereoselectivity, and the impact of substrate structures on reaction pathways. These reactions not only serve as robust tools for the streamlined synthesis of natural products but also establish a solid foundation for subsequent pharmaceutical investigations.