Chemo- and Diastereoselectivity in the Heterogeneous Catalytic Hydrogenation of 2,2′-Pyridoin and Its Derivatives
作者:Viktor Háda、Antal Tungler、László Szepesy
DOI:10.1006/jcat.2002.3652
日期:2002.7
The heterogeneous catalytic hydrogenations of 2,2′-pyridoin and related compounds, such as 2,2′-pyridil and O-acetyl-2,2′-pyridoin, were investigated over noble metal catalysts. The influence of catalytic metals, catalyst supports, solvents, acid additives, prehydrogenation, and hydrogen pressure on the chemo- and diastereoselectivity is discussed in the hydrogenation of 2,2′-pyridoin. Although hydrogenolysis
在贵金属催化剂上研究了2,2'-吡啶和相关化合物(例如2,2'-吡啶和O-乙酰基-2,2'-吡啶)的非均相催化加氢反应。在2,2'-吡啶酮加氢中讨论了催化金属,催化剂载体,溶剂,酸添加剂,预氢化和氢压对化学和非对映选择性的影响。尽管氢解和环饱和可能会作为副反应发生,但仍获得了较高的化学(90%至100%)和中等的非对映选择性值。在乙腈-水溶剂混合物中的钯黑上,氢化导致的meso / dl比为72/28,而在铑/碳上的氢化过程中,meso / dl比率是29/71。加氢的立体化学解释了氢化中的非对映异构现象,考虑到催化剂表面的顺式-反式异构化,可能的烯化以及竞争性的CC和CO还原。