Organosilicon chemistry. Part 24. Homogeneous rhodium-catalysed hydrosilation of alkenes and alkynes: the role of oxygen or hydroperoxides
作者:Hugh M. Dickers、Robert N. Haszeldine、Leslie S. Malkin、Adrian P. Mather、R. V. (Dick) Parish
DOI:10.1039/dt9800000308
日期:——
reaction, stoicheiometric quantities of hydroperoxide are required. In the hex-1-yne system, variation of the PPh3: Rh ratio gives maximum activity at 1 : 1 and, with this stoicheiometry, the reaction rate is relatively insensitive to purification of the reagents. It is suggested that the role of oxygen or hydroperoxide is to remove triphenylphosphine from the system, by oxidation, generating a highly active
对由[RhCl(PPh 3)3 ]催化的丙烯,1-己烯和1-己炔的硅氢化反应已进行了重新研究。当所有试剂都经过仔细纯化后,氢化硅烷化反应将被完全抑制,但可以通过添加氧气或叔丁基氢过氧化物来引发。在后一种情况下,反应的速率和程度不受酚自由基陷阱的存在的影响。为了获得最佳反应,需要化学计量的氢过氧化物。在hex-1-yne系统中,PPh 3的变化:Rh比在1:1时可提供最大活性,并且通过这种化学计量,反应速率对试剂的纯化相对不敏感。提出氧或氢过氧化物的作用是通过氧化从体系中除去三苯基膦,从而产生具有低PPh 3:Rh比的高活性催化剂。在“干净”的条件下,被甲硅烷基络合物[RhH(Cl)(SiR 3)(PPh 3)2 ]催化,己烯的快速异构化。