Español-Sánchez Belinda, Moradell Jesús, Galiana-Cameo María, Barrenas Eduardo, Pérez-Torrente Jesús J, Passarelli Vincenzo, Castarlenas Ricardo
Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)-Departamento de Química Inorgánica, CSIC-Universidad de Zaragoza, C/Pedro Cerbuna 12, CP, Zaragoza, 50009, Spain.
Angew Chem Int Ed Engl. 2025 Aug 18;64(34):e202507424. doi: 10.1002/anie.202507424. Epub 2025 Jun 30.
The synthesis of pentafulvenes with varied substituents has been efficiently achieved using novel rhodium-based catalysts via (2 + 2 + 1) alkyne cyclotrimerization. A rational design of the catalyst structure, including pyridonato, NHC, and CO ligands, ensures the alkyne chemoselectivity and prevents the formation of robust rhodium-fulvene species. Furthermore, the judicious choice of acidity and steric properties of different alkynes enables the preparation of cross-coupled fulvene derivatives. Stoichiometric and deuteration experiments, as well as DFT calculations, shed light on the reaction mechanism, showing that it includes an initial alkyne deprotonation, two successive alkyne insertions, cyclization, and protonolysis, the first insertion being the rate-determining step.
使用新型铑基催化剂，通过（2 + 2 + 1）炔烃环三聚反应高效地实现了具有不同取代基的戊搭烯的合成。对催化剂结构进行合理设计，包括吡啶酮基、N-杂环卡宾和一氧化碳配体，确保了炔烃的化学选择性，并防止形成稳定的铑-戊搭烯物种。此外，对不同炔烃的酸度和空间性质进行明智选择，能够制备交叉偶联的戊搭烯衍生物。化学计量和氘代实验以及密度泛函理论计算揭示了反应机理，表明该反应包括初始的炔烃去质子化、两个连续的炔烃插入、环化和质子解，第一次插入是速率决定步骤。
