An improved chemical process has been developed for the synthesis of (S,S)-DACH-Ph Trost ligand. The amidation of 2-diphenylphosphinylbenzoic acid and (S,S)-diaminocyclohexane is promoted by stoichiometric CDI and catalytic imidazole hydrochloride. The resulting product, (S,S)-DACH-Ph Trost ligand, is isolated as a white solid in 80% yield with >99% ee by simple filtration without column chromatography. The current facile process is also demonstrated on kilogram scale.

中文翻译：

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一种改进的 (S,S)-DACH-Ph Trost 配体合成可扩展工艺

已经开发了一种改进的化学方法来合成 ( S , S )-DACH-Ph Trost 配体。化学计量CDI和催化咪唑盐酸盐促进了2-二苯基次膦基苯甲酸和( S , S )-二氨基环己烷的酰胺化。所得产物 ( S , S )-DACH-Ph Trost 配体通过简单过滤而不用柱色谱法分离为白色固体，产率为 80%，ee 大于 99%。当前的简单过程也以千克为单位进行了演示。