The preparation, resolution and chemistry of 1-(3,6-dimethylpyrazin-2-yl)(2-naphthyl)diphenylphosphine, an axially chiral phosphinamine
作者:Mary McCarthy、Patrick J. Guiry
DOI:10.1016/s0040-4020(99)00066-6
日期:1999.3
treatment with triflic anhydride. A Ni-catalysed phosphinylation gave the required phosphinamine ligand 7 as a racemate. Diastereomeric palladacycles 16, formed from 7 and (+)-di-μ-chlorobis[(R)-dimethyl(1-(1-naphthyl)ethyl)aminato-C2,N]dipalladium (II) 15 were separated, after considerable effort, to give diastereomerically pure 7. Displacement of the resolving agent by reaction with 1,2-bis(diphenylphosphino)ethane
描述了以高收率五步合成标题化合物。在2-氯-3,6-二甲基吡嗪10与2-甲氧基-1-萘基硼酸9的Pd催化偶合中形成联芳基键。产物醚11的去甲基化得到醇12,通过用三氟甲磺酸酐处理将其转化为相应的三氟甲磺酸酯13。Ni催化的次膦酸酯化得到所需的次膦胺配体7为外消旋体。由7和(+)-二-μ-氯代双[(R)-二甲基(1-(1-萘基)乙基)氨基-C 2,N]二钯(II)形成的非对映异构化合物palladacycles 16经过相当大的努力,将15分离,得到非对映体纯7。通过与1,2-双(二苯基膦基)乙烷反应置换拆分剂,得到对映体7。在环境温度下发现该配体消旋。