The iridium-complexes 3 and 4 with cyclohexane-backbone derived from quinoline were easily synthesized. The key step is cis/trans stereoselective reduction of 2-(quinolin-2-yl)cyclohexanone 5 to trans-2-(quinolin-2-yl)cyclohexanol 6 using Al(Oi-Pr)3/i-PrOH and the following diastereomeric optical resolution of racemic 6 using 0.50 equiv (S)-mandelic acid in EtOAc. These complexes were used in the asymmetric hydrogenation of (E)-1,2-diphenylpropene with up to 13% ee/48% conv. using 3 and 35% ee/9% conv. using 4. For the hydrogenation of (2H-chromen-3-yl)methanol, up to 80% ee/95% yield and 72% ee/96% yield were achieved. The same configuration of the products by using 3 and 4 suggested that the absolute configuration was controlled by the configuration of the stereogenic quinolinyl-bearing carbon of the complexes.

中文翻译：

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喹啉膦环己烷骨架铱配合物的改进合成及其在不对称加氢中的应用

具有喹啉的环己烷骨架的铱配合物3和4易于合成。关键步骤是使用Al（O i- Pr）3 / i- PrOH和P - OH顺式/反式立体选择性将2-（喹啉-2-基）环己酮5还原为反式-2-（喹啉-2-基）环己醇6然后使用0.50当量（S ）-扁桃酸在EtOAc中的消旋体6的非对映异构体光学拆分。这些络合物用于（E ）-1,2-二苯丙烯的不对称加氢反应，最高可转化率为13％ee / 48％。用3 和35％ee / 9％转化。使用4 。对于（2 H-铬-3-基羰基）甲醇的氢化，获得了高达80％的ee / 95％的产率和72％的ee / 96％的产率。通过使用3和4的产物的相同构型表明，绝对构型由配合物中带有立体异构的喹啉基的碳的构型控制。