Suzuki Akane, Wu Linlin, Lin Zhenyang, Yamashita Makoto
Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho Chikusa-ku, Nagoya, 464-8603, Aichi, Japan.
Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Hong Kong.
Angew Chem Int Ed Engl. 2021 Sep 13;60(38):21007-21013. doi: 10.1002/anie.202108530. Epub 2021 Aug 24.
This manuscript describes the first example of an alkyne insertion to the Au-B bond of a di(o-tolyl)borylgold complex to afford a cis-2-borylalkenylgold complex, and its isomerization to result in interchanging substituents on the alkenyl carbon atom and the boron atom. The former reaction is the first example of an alkyne insertion to a Au-B bond. In the latter reaction, the regiochemistry of the isomerized alkenylgold products varied depending on the substituents. DFT calculations revealed the formation of gold alkynylborates as a common intermediate via a "retro-1,2-metalate shift", which can be considered as an anti-β-carbon/silicon elimination, and identified a subsequent 1,2-metalate shift as the regiochemistry-determining step. Relative energies of the transition states to each isomer and natural-bond-orbital (NBO) analyses were used to clearly rationalize the regiochemistry of the products.
本手稿描述了首例炔烃插入二（邻甲苯基）硼基金配合物的Au-B键以生成顺式-2-硼基烯基金配合物，以及其异构化导致烯基碳原子和硼原子上的取代基互换的情况。前一个反应是首例炔烃插入Au-B键的反应。在后一个反应中，异构化烯基金产物的区域化学因取代基而异。密度泛函理论（DFT）计算表明，通过“逆向1,2-金属迁移”形成金炔基硼酸盐作为常见中间体，这可被视为反β-碳/硅消除反应，并确定随后的1,2-金属迁移是区域化学决定步骤。使用各异构体过渡态的相对能量和自然键轨道（NBO）分析来清晰地解释产物的区域化学。
