کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1328390 | 977569 | 2006 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Syntheses of C1-symmetric bidentate ligands having pyridyl and 1,3-Thiazolyl, 1-methylimidazolyl or pyrazinyl donor groups for enantioselective palladium-catalyzed allylic substitution and copper-catalyzed cyclopropanation Syntheses of C1-symmetric bidentate ligands having pyridyl and 1,3-Thiazolyl, 1-methylimidazolyl or pyrazinyl donor groups for enantioselective palladium-catalyzed allylic substitution and copper-catalyzed cyclopropanation](/preview/png/1328390.png)
New chiral C1-symmetric bidentate ligands, which possess two different nitrogen heterocycles, 1,3-thiazolyl, 1-methylimidazolyl or pyrazinyl and one pyridyl group, were prepared by Kröhnke condensation in 36–59% overall yield. Stable Pd(II)-allyl and Cu(II) chloride complexes formed by some of the ligands were obtained in 60–65% yields. X-ray crystal structure analysis of a copper(II) complex having 1-methylimidazolyl group indicated that it is a μ-chloro bridge dimer. The Pd(II)-allyl complexes were found to be active catalysts in the asymmetric allylic substitution of 1,3-diphenylprop-2-enyl acetate. The best result observed was 85% e.e. and 99% isolated yield. In addition, the in situ generated Cu(OTf)2 complexes were found to be active catalysts in cyclopropanation of styrene with ethyl diazoacetate.
Chiral bidentate ligands, which possess 1,3-thiazolyl, 1-methylimidazolyl or pyrazinyl and one pyridyl group, were prepared. X-ray crystal structure analysis of a copper(II) complex having 1-methylimidazolyl group indicated that it is a μ-chloro bridge dimer. The Pd(II) and Cu(II) complexes were active catalysts in the asymmetric allylic substitution and cyclopropanation respectively.Figure optionsDownload as PowerPoint slide
Journal: Journal of Organometallic Chemistry - Volume 691, Issue 26, 15 December 2006, Pages 5664–5672