(1S,2S)-DPEN修饰的Ir/Al2O3催化苯乙酮及其衍生物的不对称加氢反应$

在碱性条件下制备了三氧化二铝负载的铱(Ir/γ-Al2O3)催化剂,并用于苯乙酮及其衍生物的不对称催化加氢反应.考察了不同的碱、碱浓度、手性二胺(1S,2S)-1,2-二苯基乙二胺(1S,2S)-DPEN]浓度、反应温度和反应压力对催化剂及反应的影响.结果显示,在优化反应条件下,该催化剂表现出较高的催化活性和良好的对映选择性,其中异丁酰苯不对称催化加氢反应的对映选择性达到了80.3%.该催化剂不需要使用任何稳定剂,制备方法简单,催化性能稳定,通过简单的离心分离即可循环使用.

Asymmetric Hydrogenation of Acetophenone and Its derivatives Catalyzed by (1S,2S)-DPEN Modified Ir/γ-Al2O3

Under the basic conditions, an efficient catalyst without any stabilizer was prepared and applied in the asymmetric hydrogenation of acetophenone and its derivatives. The effects of different base, concentration of (1S,2S)-diphenylethylenediamine(1S,2S)-DPEN] and base, reaction temperature and pressure of hydrogen on the asymmetric hydrogenation of acetophenone were investigated in detail. The results showed that this catalytic system had high activity and moderate enantioselectivity for the asymmetric hydrogenation of acetophenone and its derivatives. Under the optimum conditions, a good enantiomeric excess(e.e.) value of 80.3% was obtained for asymmetric hydrogenation of isobutyrophenone. Especially, the catalyst preparation is simple and no stabilizer was applied. The catalyst performance is steady and the catalyst can be reused several times through the facilitative separation of the catalyst from the reaction medium.