Selective C-arylation of free (NH)-heteroarenes via catalytic C-H bond functionalization.
Selective C-arylation of free (NH)-heteroarenes via catalytic C-H bond functionalization.
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DOI：
10.1021/ja034848
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发表时间：
2003-04
影响因子：
15
通讯作者：
B. Sezen;D. Sames
中科院分区：
文献类型：
--
作者：
B. Sezen;D. Sames
A new system for palladium-catalyzed arylation of a broad spectrum of free (NH)-heteroarenes has been developed (indole, pyrrole, pyrazole, 2-phenylimidazole, imidazole, benzimidazole, and purine). Remarkable selectivity has been achieved in the presence of MgO base, providing single C-arylation products, while no N-arylation and no bis-arylation products have been detected. In the case of free imidazole, exclusive C-4 arylation may be switched to exclusive 2-arylation by the addition of CuI to the Pd/Ph3P/MgO system. When free aryl-(NH)-azoles are desired, direct arylation eliminates three steps in comparison to standard methods, including N-protection, stoichiometric metalation or halogenation, and N-deprotection.
