Phosphorus lone pairs stabilization of carbocations: the synthesis and dynamics of unsymmetrical methylene phosphonium ions
作者:Udo Heim、Hans Pritzkow、Hartmut Schönberg、Hansjörg Grützmacher
DOI:10.1039/c39930000673
日期:——
Halide abstractions from P-chlorinated phosphorus ylides 9a–c either by AlCl3 or SnCl2 yield unsymmetrical methylene phosphonium ions 10a–c in which energy barriers > 83 kJ mol–1 for the rotation around the PC have been estimated by NMR techniques. The salts with AlCl4– counteranions are stable, but compounds with SnCl3– anions decompose stereoselectively to unsymmetrical methylene phosphanes, SnCl2
通过AlCl 3或SnCl 2从P氯化磷的磷化物9a – c中提取卤化物会产生不对称的亚甲基phospho离子10a – c,其中已通过NMR技术估算了围绕PC旋转的能垒> 83 kJ mol –1。用的AlCl盐4 -抗衡阴离子是稳定的,但与化合物的SnCl 3 -的阴离子分解立体选择性不对称到亚甲基膦,的SnCl 2和Bu吨氯。