Bagi Péter, Varga Bence, Szilágyi András, Karaghiosoff Konstantin, Czugler Mátyás, Fogassy Elemér, Keglevich György
Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Budapest, Hungary.
Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, Budapest, Hungary.
Chirality. 2018 Apr;30(4):509-522. doi: 10.1002/chir.22816. Epub 2018 Jan 23.
As an example of acyclic P-chiral phosphine oxides, the resolution of ethyl-(2-methylphenyl)-phenylphosphine oxide was elaborated with TADDOL derivatives, or with calcium salts of the tartaric acid derivatives. Besides the study on the resolving agents, several purification methods were developed in order to prepare enantiopure ethyl-(2-methylphenyl)-phenylphosphine oxide. It was found that the title phosphine oxide is a racemic crystal-forming compound, and the recrystallization of the enantiomeric mixtures could be used for the preparation of pure enantiomers. According to our best method, the (R)-ethyl-(2-methylphenyl)-phenylphosphine oxide could be obtained with an enantiomeric excess of 99% and in a yield of 47%. Complete racemization of the enantiomerically enriched phosphine oxide could be accomplished via the formation of a chlorophosphonium salt. Characterization of the crystal structures of the enantiopure phosphine oxide was complemented with that of the diastereomeric intermediate. X-ray analysis revealed the main nonbonding interactions responsible for enantiomeric recognition.
作为无环P-手性氧化膦的一个例子，用TADDOL衍生物或酒石酸衍生物的钙盐详细阐述了乙基-(2-甲基苯基)-苯基氧化膦的拆分。除了对拆分剂的研究外，还开发了几种纯化方法以制备对映体纯的乙基-(2-甲基苯基)-苯基氧化膦。发现标题氧化膦是一种外消旋晶体形成化合物，对映体混合物的重结晶可用于制备纯对映体。根据我们的最佳方法，(R)-乙基-(2-甲基苯基)-苯基氧化膦可以以99%的对映体过量和47%的产率获得。对映体富集的氧化膦可以通过形成氯代鏻盐来完全外消旋化。对映体纯氧化膦的晶体结构表征与非对映体中间体的晶体结构表征相辅相成。X射线分析揭示了负责对映体识别的主要非键相互作用。
