High performance of Rh(Phebox) catalysts in asymmetric reductive aldol reaction: High anti-selectivity
High performance of Rh(Phebox) catalysts in asymmetric reductive aldol reaction: High anti-selectivity
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DOI：
10.1021/ja050698m
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发表时间：
2005-05-18
影响因子：
15
通讯作者：
Matsuda, I
中科院分区：
文献类型：
--
作者：
Nishiyama, H;Shiomi, T;Matsuda, I
手性铑（双恶唑啉基苯基）配合物（1mol%）在50 °C下有效催化醛和α，β-不饱和酯的不对称还原Aldol反应，反应时间约为10 min. 0.5 - 1.0 h，得到相应的β-羟基丙酸酯，具有极高的反选择性（高达98%）和对映选择性（高达96%ee）。立体化学结果可能是由于涉及铑-（E）-烯醇化物的椅状环状过渡态。
Chiral rhodium(bisoxazolinylphenyl) complexes (1 mol %) efficiently catalyze the asymmetric reductive aldol reaction of aldehydes and α,β-unsaturated esters at 50 °C for ca. 0.5−1.0 h with several hydrosilanes to give the corresponding β-hydroxypropionates with extremely high anti-selectivity (up to 98%) and enantioselectivity (up to 96% ee). The stereochemical outcome is likely due to a chairlike cyclic transition state involving rhodium-(E)-enolate.