Dinuclear Palladacyclic Complexes Derived from C−N Cleavage of an Imidazolium Salt: Synthesis, Structural Characterization, and Their Uses for C−C Coupling

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• 作者：Jiansheng Ye ; Xiaoming Zhang ; Wanzhi Chen ; Shigeru Shimada
• 刊名：Organometallics
• 出版年：2008
• 出版时间：August 25, 2008
• 年：2008
• 卷：27
• 期：16
• 页码：4166-4172
• 全文大小：235K
• 年卷期：v.27,no.16(August 25, 2008)
• ISSN：1520-6041

文摘

Cleavage of a C−N bond of 3,6-(N-n-butylimidazolidenyl)pyridazine salt in its reactions with Ag₂O and Pd(OAc)₂ was observed. Subsequent palladation of the resultant N-n-butylimidazole resulted in the isolation of two novel dinuclear palladacyclic complexes. Both complexes consist of a Pd₂C₂N₂ core with two palladium doubly bridged by anionic imidazoles in N,C5- or N,C2-coordination fashion. Accompanied with the C−N bond cleavage and palladation processes, addition of imidazole C−H to the CN bond of acetonitrile occurred in the reaction of Pd(OAc)₂ and 3,6-(N-n-butylimidazolidenyl)pyridazine. All compounds have been fully characterized by the usual spectroscopic techniques, and their X-ray molecular structures are described. The two palladacyclic complexes show good catalytic activities in Heck−Mizoroki and Suzuki coupling reactions of activated aryl bromides.