Transfer hydrogenolysis of aryl halides and other hydrogen acceptors by formate salts in the presence of palladium/carbon catalyst
Transfer hydrogenolysis of aryl halides and other hydrogen acceptors by formate salts in the presence of palladium/carbon catalyst
复制标题
DOI：
10.1021/jo00021a034
复制
发表时间：
1991-10
影响因子：
3.6
通讯作者：
H. Wiener;J. Blum;Y. Sasson
中科院分区：
文献类型：
--
作者：
H. Wiener;J. Blum;Y. Sasson
在三相体系中，Pd/C催化的卤代芳烃转移氢解反应需要将三种底物，即芳基卤化物受体、甲酸盐阴离子和水，以特定的顺序吸附到催化剂表面的一个位置上。这种独特的反应机理需要对反应条件进行精细的优化。通过竞争动力学实验确定了各种氢受体对催化剂的亲和力大小顺序为：碘苯>；苯乙炔>；苯乙烯>；溴苯>；硝基苯>；氯苯>；氟苯。在整个转移-加氢过程中，决定反应速率的步骤是给电子体对催化剂的吸附。
The Pd/C-catalyzed transfer hydrogenolysis of aryl halides by formatesalts in a triphase system requires the absorption of all three substrates, the aryl halide acceptor, the formate anion, and the water, to a single site on the catalyst surface in a specific order. This unique mechanism necessitates delicate optimizationof reaction conditions. The affinity of various hydrogen acceptors to the catalyst was determined by competitive kinetic experiments to be in thedecreasing order: iodobenzene> phenylacetylene> styrene> bromobenzene> nitrobenzene> chlorobenzene> fluorobenzene. The rate-determining step in the overall transfer-hydrogenation process is the adsorption of the donors to the catalyst.