摘要 : Phenyl-trimethylsilylethyne, H5C6-C C-SiMe3, reacted with different dialkylgallium hydrides, R2Ga-H (R = Me, Et, nPr, iPr, tBu), by the addition of one Ga-H bond to its C C triple bond (hydrogallation). The gallium atoms attacked ... 展开 Phenyl-trimethylsilylethyne, H5C6-C C-SiMe3, reacted with different dialkylgallium hydrides, R2Ga-H (R = Me, Et, nPr, iPr, tBu), by the addition of one Ga-H bond to its C C triple bond (hydrogallation). The gallium atoms attacked selectively those carbon atoms, which were also attached to trimethylsilyl groups. The cis arrangement of Ga and H across the resulting C=C double bonds resulted only for the sterically most shielded di(tert-butyl)gallium derivative, while in all other cases spontaneous cis/trans rearrangement Occurred with the quantitative formation of the trans addition products. The diethyl compound Et2Ga-C(SiMe3)= C(H)-C6H5 (2) gave by substituent exchange the secondary products E1Ga[C(SiMe3)=C(H)-C6H5](2) (7, Z,Z) and Ga[C(SiMe3)= C(H)-C6H5](3) (8). Interestingly, compound 8 has two alkenyl groups with a Z configuration, while the third C C double bond has the cis arrangement of Ga and H (E configuration). The reversibility of the cis/trans isomerisation of hydrogallation products was observed for the first time. tert-Butyl-phenylethyne gave the simple addition product, R2Ga(C6H5)=C(H)-CMe3 (9), only with di(n-propyl)galliurn hydride. 收起