Enantioselective Hydrogenation of Ethyl Pyruvate over Pt/Alumina Modified by (R)-1-(1-Naphthyl)ethylamine Derivatives
作者:B. Minder、M. Schürch、T. Mallat、A. Baiker、T. Heinz、A. Pfaltz
DOI:10.1006/jcat.1996.0144
日期:1996.5
A new chiral modifier, (R)-1-(1-naphthyl)ethylamine, has been tested in the enantioselective hydrogenation of ethyl pyruvate to ethyl lactate over 5 wt% Pt/Al2O3. The influence of catalyst (2–28 g liter−1) and modifier concentration (0–20 mM), temperature (282–333 K), pressure (1–75 bar), and solvents was studied in a slurry reactor. The 82% enantiomeric excess (ee) at full conversion was achieved
在丙酮酸乙酯在5wt%的Pt / Al 2 O 3上对映体选择性氢化为丙酮酸乙酯的过程中,已经测试了一种新的手性改性剂(R)-1-(1-萘基)乙胺。催化剂(2–28 g升-1)和改性剂浓度(0–20 m M的影响),温度(282–333 K),压力(1–75 bar)和溶剂在淤浆反应器中进行了研究。优化反应参数后,在乙酸中达到82%的对映体过量(ee)。在温和的条件下,新的改性剂提供的ee优于金鸡纳生物碱。在高于10 bar的压力和288 K以上的温度下ee的下降归因于萘环的部分氢化,这阻碍了平行于平坦Pt表面的改性剂的吸附。与外消旋反应相比,在流速为673 K的氢气中对催化剂进行热处理后,在273–298 K的乙酸中进行好氧处理后,观察到最大速率加速为12。结果表明,萘乙胺只是实际改性剂的前体,由萘乙胺和丙酮酸乙酯原位缩合成相应的亚胺,然后还原C = N键。通过还原烷基化制备萘乙胺的其他