Work

Rhodium‐Catalyzed 1,5‐Sigma Migratory Ring Expansion of gem ‐Difluorodienyl Cyclopropanes and Cyclobutanes

Year: 2025

Type: article

Abstract: group for both DECPs and DECBs, the resulting substrates of gem-difluorodienyl cyclopropanes (df-DECPs) and gem-difluorodienyl cyclobutanes (df-DECBs) can achieve this reaction, which has broad reaction scope and high efficiency to give seven- and eight-membered carbocycles with a carbonyl group. The keys to the success of this reaction are: oxidative cyclometalation becomes easier with the help of two F atoms; the metallacycle intermediate can detour the sluggish reductive elimination by defluorination to generate Rh carbene intermediate (defluorocarbenation process), which can undergo easier carbene migratory insertion and β-H elimination, giving rise to the final products. Mechanistic studies via experiments and quantum chemical calculations support the proposed mechanism. The gem-difluoro ene in the substrates of df-DECPs and df-DECBs of the present SMRE reaction can be regarded as a ketene surrogate, and this strategy can be exploited in many transition-metal-catalyzed reactions in the future.

Source: Angewandte Chemie International Edition

DOI: 10.1002/anie.202500074

Authors: Zhiqiang Huang, Sixuan Zhao, Zhi‐Xiang Yu

Institutions: Peking University, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education

Language: English

Topic: Cyclopropane Reaction Mechanisms

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: bronze

Funders: National Natural Science Foundation of China, Peking University

Award: 金属催化环加成反应机理研究和反应发展