Photoinduced Generation of Active Intermediates from Unmodified 1,3‐Dicarbonyl Compounds for Organic Transformations

• Published in: European journal of organic chemistry 2024-04, Vol.27 (14), p.n/a
• Main Authors: Li, Hao‐Yuan, Niu, Xiaoying, Yang, Xiu‐Long
• Format: Article
• Language: English
• Subjects: 1,3-dicarbonyl compounds; Carbonyl compounds; Chemical reactions; photoexcitation; photoinduced electron transfer; triplet state; α-carbon radical
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.202400102

Photocatalysis utilizes light as the initial driving force for chemical reactions, enabling reactions with high energy barriers in traditionally thermal chemistry to proceed under mild conditions. 1,3‐Dicarbonyl compounds occur as important active molecules in nature and are intermediates in pharmaceutical syntheses. In recent years, there have been numerous studies of these compounds, and it is common practice to pre‐modify them before the reaction, which is, however, unfavorable for the atom economy of the process. This paper provides a comprehensive review of the latest advancements in the site‐specific activation of unmodified 1,3‐dicarbonyl compounds by photoinduction. The focus is on elucidating the mechanisms of these reactions to provide insights and directions for future research in designing novel reactions. This paper reviews the advancements in the site‐specific activation of unmodified 1,3‐dicarbonyl compounds via photoinduction, focusing on two activation mechanisms. The first involves photoinduced redox reactions, activating the α‐position of the carbonyl group. The second occurs via absorption of photons in the enol form or energy transfer through a photocatalyst, leading to an excited‐state transition and subsequent reactions such as 6π cyclization or the de Mayo reaction.