(1S,2S)-DPEN修饰的3%Ir/SiO2/2TPP催化苄叉丙酮的不对称加氢

在温和的条件下制备了负载型3%(w)Ir/SiO2/2TPP(三苯基膦)催化剂, 并且考察了(1S,2S)-1,2-二苯基乙二胺[(1S,2S)-DPEN]作为手性修饰剂对其催化苄叉丙酮不对称加氢反应性能的影响. 结果表明, 手性修饰剂(1S,2S)-DPEN的加入, 对苄叉丙酮不对称加氢反应活性和C=O加氢的选择性都有很好的促进作用. 经优化条件, 在40 ℃下, LiOH浓度为0.375 mol·L-1的甲醇溶液中, 氢气压力为6 MPa, 反应8 h后, 苄叉丙酮的转化率大于99.0%, 对不饱和醇的选择性大于99.0%, 不饱和醇的对映选择性(ee)值达到48.1%.

Asymmetric Hydrogenation of Benzalacetone Catalyzed by(1S,2S)-DPEN Modified 3%Ir/SiO_2/2TPP Catalysts

The enantioselective hydrogenation of benzalacetone catalyzed by the chiral diamine [(1S,2S)-1,2-diphenyl-1,2-ethylenediamine] ((1S,2S)-DPEN) modified 3%(w)Ir/SiO_2/2TPP (TPP-triphenylphosphine) was investigated. We found that (1S,2S)-DPEN could accelerate the rate of the reaction and efficiently increase the selectivity for C=O bond hydrogenation. Under the optimum reaction conditions, a LiOH concentrantion of 0.375 mol·L~(-1) in methanol, a reaction temperature of 40 ℃, a H_2 pressure of 6.0 MPa and reaction time of 8 h, the conversion of benzalacetone was more than 99.0% and the selectivity for unsaturated alcohol was more than 99.0%. The enantiomeric excess (ee) value of the unsaturated alcohol reached 48.1%.