Ruthenium- and rhodium-catalyzed direct carbonylation of the ortho C-H bond in the benzene ring of N-arylpyrazoles
Ruthenium- and rhodium-catalyzed direct carbonylation of the ortho C-H bond in the benzene ring of N-arylpyrazoles
复制标题
DOI：
10.1021/jo049864j
复制
发表时间：
2004-06-25
影响因子：
3.6
通讯作者：
Chatani, N
中科院分区：
文献类型：
--
作者：
Asaumi, T;Matsuo, T;Chatani, N
本文报道了在钌或铑配合物催化下，N-苯基吡唑苯环上C-H键的直接羰基化反应。在Ru-3（CO）（12）或Rh-4（CO）（12）存在下，N-苯基吡唑与一氧化碳和乙烯反应，苯环上的邻位C-H键发生位置选择性羰基化，生成相应的乙基酮。苯环上的各种官能团都是可以接受的。根据吡唑共轭酸的pK（a）值，N-苯基吡唑具有比预期更高的反应性。溶剂的选择对该反应有重要意义，N，N-二甲基乙酰胺（DMA）的效果最好。
The direct carbonylation of C-H bonds in the benzene ring of N-phenylpyrazoles via catalysis by ruthenium or rhodium complexes is described. The reaction of N-phenylpyrazoles with carbon monoxide and ethylene in the presence of Ru-3(CO)(12) or Rh-4(CO)(12) resulted in the site-selective carbonylation of the ortho C-H bonds in the benzene ring to give the corresponding ethyl ketones. A variety of functional groups on the benzene ring can be tolerated. N-Phenylpyrazoles have higher reactivities than would be expected, based on the pK(a) values of the conjugate acid of pyrazole. The choice of solvent for this reaction is significant, and N,N-dimethylacetamide (DMA) gives the best result.