Stereoselective addition of diphenylphosphine to substituted diphenylethynes: synthetic, NMR and X-ray crystallographic studies
作者:Jonathan L. Bookham、Darren M. Smithies、Anna Wright、Mark Thornton-Pett、William McFarlane
DOI:10.1039/a707210d
日期:——
The base-catalysed addition of diphenylphosphine to the substituted diphenylethynes RCCR′ (R = Ph, R′ = Ph, o-tolyl, m-tolyl or 2-biphenyl; R = m-tolyl, R′ = o-tolyl or m-tolyl) yielded Ph2PC(R)CHR′ and/or Ph2PCH(R)CH(R′)PPh2. Proton, 13C, 13P and two-dimensional rotating frame Overhauser enhancement 1H NMR spectra have been used to determine the stereochemical pathways of the reactions and the stereochemistry
的碱催化加成二苯基膦与上述取代diphenylethynes RC CR'(R =苯基,R'=苯基,Õ甲苯基,米甲苯基或2-联苯基; R = 米间-甲苯基,R'= ö甲苯基或米-甲苯基)产生Ph 2 PC(R)CHR'和/或Ph 2 PCH(R)CH(R')PPh 2。Proton,13 C,13 P和二维旋转框架Overhauser增强功能11 H NMR光谱已用于确定反应的立体化学途径和产物的立体化学。通常,受阻较大的炔烃最终进行单加成反应,最终生成膦基烯烃,其中Ph 2 P附着在碳原子上取代基最少,而顺式附着在烯烃质子上,而对于受阻较小的炔烃,首先形成反式异构体,然后进一步反应得到内消旋/赤型-二膦基烷烃。在相同条件下,双(邻甲苯基)乙炔不会与Ph 2 PH反应。确定了E-和Z -Ph 2的晶体结构P(Ph)C CHPh并显示与上述反应所隐含的应变模式一致的键间角变形。还制备了膦基