Cheng Zhaoyang, Li Minghua, Zhang Xu-Yang, Sun Yue, Yu Qing-Lei, Zhang Xing-Hong, Lu Zhan
Department of Chemistry, Zhejiang University, Hangzhou, 310058, China.
Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
Angew Chem Int Ed Engl. 2023 Jan 2;62(1):e202215029. doi: 10.1002/anie.202215029. Epub 2022 Nov 29.
Double hydrosilylation of alkynes represents a straightforward method to synthesize bis(silane)s, yet it is challenging if α-substituted vinylsilanes act as the intermediates. Here, a cobalt-catalyzed regiodivergent double hydrosilylation of arylacetylenes is reported for the first time involving this challenge, accessing both vicinal and geminal bis(silane)s with exclusive regioselectivity. Various novel bis(silane)s containing Si-H bonds can be easily obtained. The gram-scale reactions could be performed smoothly. Preliminarily mechanistic studies demonstrated that the reactions were initiated by cobalt-catalyzed α-hydrosilylation of alkynes, followed by cobalt-catalyzed β-hydrosilylation of the α-vinylsilanes to deliver vicinal bis(silane)s, or hydride-catalyzed α-hydrosilylation to give geminal ones. Notably, these bis(silane)s can be used for the synthesis of high-refractive-index polymers (n up to 1.83), demonstrating great potential utility in optical materials.
炔烃的双硅氢化反应是合成双硅烷的一种直接方法，然而，如果α-取代乙烯基硅烷作为中间体，则具有挑战性。在此，首次报道了钴催化的芳基乙炔的区域发散性双硅氢化反应，该反应涉及这一挑战，以专一的区域选择性获得邻位和偕位双硅烷。各种含Si-H键的新型双硅烷能够轻松制得。克级规模的反应能够顺利进行。初步机理研究表明，反应由钴催化的炔烃α-硅氢化反应引发，随后是钴催化的α-乙烯基硅烷的β-硅氢化反应以生成邻位双硅烷，或氢化物催化的α-硅氢化反应以生成偕位双硅烷。值得注意的是，这些双硅烷可用于合成高折射率聚合物（折射率高达1.83），在光学材料方面显示出巨大的潜在应用价值。
