State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
Chem Commun (Camb). 2019 Jan 29;55(10):1494-1497. doi: 10.1039/c8cc09022j.
Phosphanylhydrosilylalkynes Me2HSiC[triple bond, length as m-dash]CPAr2 (Ar = Ph, 1a; 4-MeC6H4, 1b) were synthesized, which reacted with B(C6F5)3 to produce alkenes [(E)-(C6F5)3BCH[double bond, length as m-dash]C(PAr2)SiMe2]2 (2a and 2b) and (Z)-(C6F5)2BCH[double bond, length as m-dash]C(PAr2)SiMe2(C6F5) (3a and 3b). The formation of 2a (or 2b) involved a Wrackmeyer's SiHMe2 migration followed by Si-H addition across the C[triple bond, length as m-dash]C bond, whereas, that of 3a (or 3b) involved a similar mechanism with a further C6F5 migration. The B(C6F5)3-promoted reaction of the Si-centered geminal H and C[triple bond, length as m-dash]C groups is thus realized, which may be considered as a self-hydrosilylation. Mechanistic studies by both variable temperature NMR spectroscopy and DFT calculations were accomplished.
膦基氢硅基炔烃 Me2HSiC[三重键，用破折号表示]CPAr2（Ar = Ph，1a；4-MeC6H4，1b）被合成，它们与 B(C6F5)3 反应生成烯烃[(E)-(C6F5)3BCH[双键，用破折号表示]C(PAr2)SiMe2]2（2a 和 2b）和(Z)-(C6F5)2BCH[双键，用破折号表示]C(PAr2)SiMe2(C6F5)（3a 和 3b）。2a（或 2b）的形成涉及 Wrackmeyer 的 SiHMe2 迁移，然后是 Si-H 对 C[三重键，用破折号表示]C 键的加成，而 3a（或 3b）的形成涉及类似的机制，进一步的 C6F5 迁移。因此，实现了 B(C6F5)3 促进的 Si 中心偕二氢和 C[三重键，用破折号表示]C 基团之间的反应，这可以被认为是自氢化硅烷化反应。通过变温 NMR 光谱和 DFT 计算完成了机理研究。
