Multifunctional heterocyclic scaffolds for hybrid Lewis acid/Lewis base catalysis of carbon–carbon bond formation
作者:Dennis Wiedenhoeft、Adam R. Benoit、Yibiao Wu、Jacob D. Porter、Elisia Meyle、Teresa H.W. Yeung、Raechel Huff、Sergey V. Lindeman、Chris Dockendorff
DOI:10.1016/j.tet.2016.05.014
日期:2016.7
classes of hybrid catalysts have been synthesized by tethering heterocyclic metal (Lewis acid) chelating scaffolds to several different amines capable of facilitating enamine catalysis. Oxazole, thiazole, and imidazole-based chiral precatalysts were prepared in several steps from amino acid starting materials, and these were combined with a variety of metal Lewis acids for potential use as catalysts for various
通过将杂环金属(路易斯酸)螯合支架束缚到能够促进烯胺催化的几种不同的胺上,已经合成了几种新型的杂化催化剂。由氨基酸起始原料分几步制备恶唑,噻唑和咪唑基手性预催化剂,然后将它们与多种金属路易斯酸混合,可潜在地用作形成各种碳-碳键形成的催化剂。鉴定了与活化的苯甲醛受体进行对映选择性直接羟醛反应的耐空气和湿气的催化剂,并结合脯氨酸衍生的恶唑-羧酰胺预催化剂与Zn(OTf)2获得了最佳结果或镧系(III)盐。对照研究支持以下假设,即它们充当丙醛和4-硝基苯甲醛的醛醇缩合反应的单分子杂化催化剂。