Neutral iridium catalysts with chiral phosphine-carboxy ligands for asymmetric hydrogenation of unsaturated carboxylic acids
作者:Shuang Yang、Wen Che、Hui-Ling Wu、Shou-Fei Zhu、Qi-Lin Zhou
DOI:10.1039/c6sc03764j
日期:——
We developed neutral iridium catalysts with chiral spiro phosphine-carboxy ligands (SpiroCAP) for asymmetric hydrogenation of unsaturated carboxylic acids. Different from the cationic Crabtree-type catalysts, the iridium catalysts with chiral spiro phosphine-carboxy ligands are neutral and do not require the use of a tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF−) counterion, which is necessary
我们开发了具有手性螺环膦-羧基配体 (SpiroCAP) 的中性铱催化剂,用于不饱和羧酸的不对称氢化。与阳离子 Crabtree 型催化剂不同,具有手性螺环膦-羧基配体的铱催化剂是中性的,不需要使用四[3,5-双(三氟甲基)苯基]硼酸盐 (BAr F -) 抗衡离子,这是稳定阳离子 Crabtree 型催化剂所必需的。中性铱催化剂的另一个优点是它们具有高稳定性并且在空气中具有长寿命。具有手性螺环膦-羧基配体的新型铱催化剂在各种不饱和羧酸的不对称氢化中表现出前所未有的高对映选择性(高达 99.4% ee),特别是对于 3-烷基-3-亚甲基丙酸而言,这对其他手性的底物具有挑战性催化剂。