Abstract
Treatment of sterically highly shielded terminal alkynes, H-C≡C-aryl, with dialkylaluminium and dialkylgallium hydrides, R2E-H, afforded by hydrogen release dimeric dialkylelement alkynides with a four-membered E2C2 heterocycle independent of the bulk of the aryl groups. A rare example of a monomeric alkynylaluminium compound was only obtained with very bulky CH(SiMe3)2 groups attached to the metal atoms and by salt elimination reaction. The steric shielding by the bulky aryl groups did not prevent condensation reactions. Hydroalumination of 1-(trimethylsilyl)-2-(2,6- dimethylphenyl)ethyne using Me2Al-H resulted in a divinyl compound by elimination of trimethylaluminium
摘要
用二烷基铝和二烷基镓氢化物 R2E-H 处理具有高度立体屏蔽的 H-C≡C-芳基末端炔,通过氢释放可得到具有独立于芳基基团的四元 E2C2 杂环的二聚二烷基元素炔。只有在金属原子上连接了非常笨重的 CH(SiMe3)2 基团,并通过消盐反应,才能得到单体炔铝化合物的罕见实例。笨重芳基的立体屏蔽并不能阻止缩合反应。使用 Me2Al-H 对 1-(三甲基硅基)-2-(2,6- 二甲基苯基)乙炔进行氢化氨化,通过消除三甲基铝,可得到二乙烯基化合物。