Modular ligand variation in calcium bisimidazoline complexes: effects on ligand redistribution and hydroamination catalysis
作者:James S. Wixey、Benjamin D. Ward
DOI:10.1039/c1dt10732a
日期:——
A series of calcium complexes supported by chiral bisimidazoline ligands have been studied in the catalytic intramolecular hydroamination/cyclisation of amino-olefins. The complexes [Ca(R-BIM)N(SiMe3)2}(THF)] (R = 4-C6H4Me, 5a, 4-C6H4F, 5b and tBu, 5c) have given competitive enantioselectivities (up to 12%) when compared to current literature studies involving calcium. Bisimidazolines offer a significant advance over similar bisoxazoline ligands, by allowing a greater structural variance through a modular synthetic pathway.
一系列由手性双咪唑啉配体支持的钙复合物已被研究用于氨基烯烃的催化分子内氢胺化/环化反应。复合物 [Ca(R-BIM)N(SiMe3)2}(THF)](R = 4-C6H4Me, 5a;4-C6H4F, 5b 和 tBu, 5c)在与当前文献中涉及的钙相比时,表现出竞争性的对映选择性(最高可达 12%)。双咪唑啉在结构变异方面相较于类似的双噁唑啉配体提供了显著的进展,因为它通过模块化合成途径允许更大的结构多样性。