Enantioselective catalysis in water: Mukaiyama-aldol condensation promoted by copper complexes of bisoxazolines supported on poly(ethylene glycol)
作者:Maurizio Benaglia、Mauro Cinquini、Franco Cozzi、Giuseppe Celentano
DOI:10.1039/b409971k
日期:——
supported on a modified poly(ethylene glycol) were shown to be effective Cu(II) ligands for the enantioselective Mukaiyama-aldol condensation of various aldehydes with the trimethylsilyl keteneacetal of methyl isobutyrate carried out in water. Enantiomeric excesses comparable to those obtained with nonsupported ligands in the same solvent were observed. The solubility of the ligand in water, ensured by
负载在改性聚乙二醇上的(S)-3-苯基-2-氨基丙醇衍生的双恶唑啉被证明是有效的Cu(II)配体,可用于多种醛与异丁酸甲酯的三甲基甲硅烷基烯酮缩醛的对映选择性Mukaiyama-Aldol缩合反应。在水中进行。观察到与在相同溶剂中用不支持的配体获得的对映体过量相当。配体在水中的溶解度(通过聚合物载体的存在得以确保)使得催化剂再循环程序非常方便,该过程包括通过在Et(2)O中萃取并向含催化剂的新鲜试剂中添加反应试剂来简单地除去反应产物。水溶液。在三个反应循环中,催化剂的化学和立体化学效率仅在使用过程中被轻微侵蚀。