Zheng Xuejuan, Huang Fanping, Li Xinyuan, Zhuo Kaiyue, Chen Dafa, Luo Ming, Xia Haiping
Shenzhen Grubbs Institute, Department of Chemistry, Guangming Advanced Research Institute, Southern University of Science and Technology Shenzhen 518055 China
Chem Sci. 2024 May 3;15(22):8443-8450. doi: 10.1039/d4sc01993h. eCollection 2024 Jun 5.
Isomerization reactions of unsaturated molecules offer an efficient strategy in atom-economical synthesis. Although isomerization reactions of unsaturated organic and organometallic compounds, such as alkenes, alkynes, and metal carbynes, have been achieved, those of metal vinylidene units that contain cumulated double bonds have never been reported. Herein, we inaugurally discovered isomerization reactions of metal vinylidene units protonation and deprotonation reactions of metal carbenes. Experimental and theoretical investigations indicate that the electrical characteristics of substituents on the rings play a crucial role in controlling the formation of metal vinylidene units. The isomerization reactions of metal vinylidene units were driven by thermodynamic forces. Moreover, one of the angles at metal vinylidenes was found as 126.9°, representing the smallest angle in metal vinylidenes and the first cyclic 4d transition metal (Ru) vinylidene complex was successfully isolated. These investigations unveil novel structures and reactivity for metal vinylidenes, offering a fresh perspective on the isomerization reactions of unsaturated molecules containing cumulative unsaturated bonds.
不饱和分子的异构化反应为原子经济性合成提供了一种有效策略。尽管不饱和有机化合物和有机金属化合物（如烯烃、炔烃和金属卡宾）的异构化反应已经实现，但含有累积双键的金属亚乙烯基单元的异构化反应从未被报道过。在此，我们首次发现了金属亚乙烯基单元的异构化反应——金属卡宾的质子化和去质子化反应。实验和理论研究表明，环上取代基的电子特性在控制金属亚乙烯基单元的形成中起着关键作用。金属亚乙烯基单元的异构化反应是由热力学驱动力驱动的。此外，发现金属亚乙烯基的一个角度为126.9°，这是金属亚乙烯基中最小的角度，并且首次成功分离出环状4d过渡金属（Ru）亚乙烯基配合物。这些研究揭示了金属亚乙烯基的新结构和反应活性，为含有累积不饱和键的不饱和分子的异构化反应提供了新的视角。
