网上投注站-赌场网上投注皇冠-利高国际娱乐网

Recently, the research team from the School of Chemistry and Chemical Engineering at Guangxi University has made new progress in the palladium-catalyzed reaction of nitroalkanes with gem-difluorocyclopropanes. The related findings have been published in the internationally renowned academic journal Angewandte Chemie International Edition under the title "Ligand?Switched Regiodivergent Fluoroallylic Alkylation of Secondary Nitroalkanes via an Unusual Inner?Sphere Pathway." The first author and corresponding author of the paper is Assistant Professor Yu Lin from the School of Chemistry and Chemical Engineering at Guangxi University; co?corresponding authors are Professor Duan Wengui from the same school, Professor Huang Genping from Tianjin University, Associate Professor Lyu Leiyang from Renmin University of China, and Professor Li Chaojun from McGill University, Canada. Guangxi University is the first and corresponding affiliation of the paper.

The Tsuji–Trost reaction is one of the cornerstones of modern organic synthesis. However, due to longstanding mechanistic constraints, the reaction of nitroalkanes with allylic electrophiles typically follows an outer?sphere pathway, predominantly yielding linear products. For sterically hindered secondary nitroalkanes, achieving selective branched allylation remains a formidable challenge because of their significant α?site steric hindrance, their inherent preference for outer?sphere attack, and the competitive O?allylation from nitronate oxygen anions.

To address this challenge, the team utilized the electrophilic fluoro?π?allyl palladium species generated in situ from gem-difluorocyclopropanes under palladium catalysis. By fine?tuning the steric and electronic effects of monophosphine ligands, they successfully switched the reaction pathway from the conventional outer?sphere mechanism to an unusual inner?sphere 3,3'?reductive elimination pathway, achieving precise control over reaction selectivity. Simply by switching the ligand, either linear or branched products could be selectively obtained from the same reaction system. This method exhibits broad substrate scope, is applicable to the late?stage modification of complex molecules, and the resulting products can be further converted into a variety of high?value?added compounds.

Mechanistic studies indicate that the ligand plays a key role in diverting the reaction pathway. This work overturns the traditional understanding that nitroalkanes can only participate in the Tsuji–Trost reaction through an outer?sphere mechanism. It not only enables switchable control of regioselectivity and develops an efficient new method for constructing monofluoroalkenes, but also redefines the reactivity paradigm of nitroalkanes in Tsuji–Trost chemistry, offering new insights for developing non?classical allylation reactions.

This research was supported by the National Natural Science Foundation of China, the Guangxi Natural Science Foundation, the Guangxi Science and Technology Base and Talent Special Project, and the Guangxi Graduate Education Innovation Program.