Enantiomeric products formed via different mechanisms: asymmetric hydrogenation of an α,β-unsaturated carboxylic acid involving a Ru(CH3COO)2[(R)-binap] catalyst
作者:Masahiro Yoshimura、Yoshitaka Ishibashi、Kengo Miyata、Yuhki Bessho、Masaki Tsukamoto、Masato Kitamura
DOI:10.1016/j.tet.2007.08.071
日期:2007.11
Hydrogenation of (Z)-3-phenyl-2-butenoic acid with a Ru(CH3COO)2[(R)-binap] (BINAP=2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) catalyst in methanol gives (S)-3-phenyl-2-butanoic acid and its R enantiomer in a 97:3 (4 atm) to 94:6 (100 atm) ratio in quantitative yield. Both hydrogen gas and protic methanol participate in the saturation of the olefinic bond. Analysis of the products obtained using
用Ru(CH 3 COO)2 [(R)-binap](BINAP = 2,2'-双(二苯基膦基)-1,1'-联萘基)加氢(Z)-3-苯基-2-丁烯酸甲醇中的甲醇催化剂以定量收率得到97:3(4 atm)至94:6(100 atm)的(S)-3-苯基-2-丁酸及其R对映异构体。氢气和质子甲醇都参与烯键的饱和。使用(Z)-3-苯基-2-丁烯酸-3- 13 C和H 2,1:1 H 2 –D 2混合物或D 2在CH 3中的获得的产物的分析OD表明几个催化循环是可操作的,显示出不同的反应性和立体选择性。主要的S对映异构体主要是通过标准的Ru一氢化物机理形成的,而次要的R对映异构体则是通过更复杂的途径生成的。