Novel Chiral (Salen)MnIII Complexes Containing a Calix[4]arene Unit as Catalysts for Enantioselective Epoxidation Reactions of (Z)-Aryl Alkenes
作者:Maria E. Amato、Francesco P. Ballistreri、Andrea Pappalardo、Gaetano A. Tomaselli、Rosa M. Toscano、David J. Williams
DOI:10.1002/ejoc.200500138
日期:2005.8
New asymmetric (salen)MnIII and UO2 complexes containing a calix[4]arene unit in the ligand framework were synthesized. The UO2 complexes were characterized by 1H-, 13C-, 2D TOCSY and T-ROESY NMR spectroscopy. Furthermore, the structure of one UO2 complex was determined by single-crystal X-ray analysis. The data showed that UO2 complexes, which can be considered in first approximation models of the
合成了新的不对称 (salen) MnIII 和 UO2 配合物,在配体框架中含有杯 [4] 芳烃单元。UO2 配合物通过 1H-、13C-、2D TOCSY 和 T-ROESY NMR 光谱表征。此外,通过单晶 X 射线分析确定了一种 UO2 配合物的结构。数据表明,可以在 Mn=O 氧化剂活性物质的一阶近似模型中考虑的 UO2 配合物具有手性口袋,并采用相关构象来提高氧转移过程的选择性。模型烯烃与 MnIII 配合物的环氧化数据显示出适中的 ee 值,并不能确定杯[4]芳烃单元可能能够通过分子识别机制影响选择性。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)