摘要
采用浸渍法在温和条件下制备了羟基磷灰石负载的铱催化剂(Ir/HAP),并以X射线衍射(XRD),透射电子显微镜(TEM),X射线光电子能谱(XPS),比表面积测定(BET)以及附带能量散射X射线谱的扫描电子显微镜(SEM-EDS)等手段对载体和催化剂进行了表征.以(1S,2S)-1,2-二苯基乙二胺((1S,2S)-DPEN)为手性修饰剂时,该催化剂对苯乙酮及其衍生物不对称加氢反应表现出较高活性和对映选择性(ee).在氢气压力为3.0MPa、303K条件下反应3h,苯乙酮及其衍生物的加氢转化率在94.7%以上,其中生成2′-(三氟甲基)苯乙醇的对映选择性高达81.5%.在不使用其它配体作稳定剂的情况下,该结果比目前文献报道值高.通过对比研究发现,羟基磷灰石作为载体优于二氧化硅等其它无机载体.催化剂通过简单离心分离可循环使用多次,无明显的金属铱流失.
A novel catalyst was prepared for the first time by supporting iridium on porous hydroxyapatite （Ir/HAP）. The catalyst was characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM） equipped with an energy dispersive X-ray spectroscopy （EDS）, X-ray photoelectron spectroscopy （XPS）, and Brunauer-Emmett-Teller （BET） surface area analysis. In the presence of （1S,2S）-1,2-diphenyl-1,2-ethylenediamine （（1S,2S）-DPEN）, the catalytic properties of the catalyst were investigated by the asymmetric hydrogenation of aromatic ketones. Under optimum reaction conditions of temperature T=303 K, pressure p=3.0 MPa, and reaction time t=3 h, the conversion of aromatic alcohols that were produced from the hydrogenation of acetophenone and its derivatives reached 94.7%. The enantiomeric excess （ee） value for the 2′-（trifluoromethyl） phenethyl alcohol was 81.5%. Without using other ligands as stabilizers, the enantiomeric excess value was found to be higher than that reported in literature. As a catalyst carrier, hydroxyapatite is superior to SiO2 and other inorganic carders. The catalyst is reusable with no sign of Ir leaching.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2009年第10期2039-2044,共6页
Acta Physico-Chimica Sinica
基金
教育部博士点基金(20030610022)资助项目~~
