کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1327882 | 977512 | 2005 | 7 صفحه PDF | دانلود رایگان |
Reaction of N,N′-dimethylbenzimidazolyl iodide (A) with Pd(OAc)2 in DMSO gives selectively trans-bis(N,N′-dimethylbenzimidazoline-2-ylidene) palladium(II) diiodide (trans-2) in 77% yield. The selective formation of the trans-coordination isomer and thus the cis–trans rearrangement is driven by the insolubility of trans-2 in DMSO. X-ray single-crystal diffraction analysis and 13C NMR spectroscopy confirm the trans-geometry of the square planar Pd(II) complex. Catalytic studies show that cis-1 and trans-2 are highly efficient in the Mizoroki–Heck coupling reaction of aryl bromides and activated aryl chlorides both in DMF and [N(n-C4H9)4]Br as ionic liquid. The catalytic activities of Pd(II) complexes with N-heterocyclic carbene ligands derived from benzimidazole are comparable to their imidazole-derived analogues.
A trans-configured benzimidazole-2-ylidene complex of palladium(II) (trans-2) was selectively obtained from the reaction of precursor A with Pd(OAc)2 in DMSO and structurally characterized. The novel complex and its cis-isomer show high catalytic activities in the Mizoroki–Heck reaction comparable to imidazole-derived carbene complexes.Figure optionsDownload as PowerPoint slide
Journal: Journal of Organometallic Chemistry - Volume 690, Issue 16, 15 August 2005, Pages 3854–3860