A series of 1-alkynes (RC≡CH where R=Et, n-Pr, n-Bu, n-C6H13, cyclohexyl, Ph, Me3Si, Me3SiCH2, and Me3SiOCH2) was found to dimerize regioselectively (>99%) to 2,4-disubstituted 1-buten-3-ynes in 92–99% yields by catalysis of (η5-C5Me5)2TiCl2/i-PrMgBr at 30 °C in 1–3 h. The catalyst system is also effective for the regioselective codimerization of various 1-alkynes with 1-ethynylcyclohexene or ethynylbenzene.
发现一系列1-
炔烃(RC≡CH,其中R=乙基、正丙基、正丁基、正己基、环己基、苯基、三甲基
硅基、三甲基
硅基亚甲基和三甲基
硅氧亚甲基)在30°C下通过(η5-C5Me5)2TiCl2/i-PrMgBr催化,经过1-3小时的反应,能够选择性二聚化(>99%),生成2,4-二取代的1-
丁烯-3-炔,产率在92%-99%之间。该催化体系对于各种1-
炔烃与1-
乙炔基
环己烯或
乙炔基苯的选择性共二聚化也同样有效。