New chiral bidentate ligands containing thiazolyl and pyridyl donors for copper-catalyzed asymmetric allylic oxidation of cyclohexene
作者:Pang-Fei Teng、Chui-Shan Tsang、Ho-Lun Yeung、Wing-Leung Wong、Hoi-Lun Kwong、Ian D. Williams
DOI:10.1016/j.jorganchem.2005.11.003
日期:2006.5
Chiral bidentate ligands 1–3, which contain a combination of thiazolyl and pyridyl donors units, were prepared. The syntheses are facile and being based on Kröhnke condensation of a pinene derivative to form the pyridine ring. Modification at the 8-position of the tetrahydroquinoline ring can be carried out by alkylation reaction with 2a and 3a but not 1a. The structure of a copper(II) perchlorate
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
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-raycrystalstructure analysis of a copper(II) complex having