Zinc Complexes of Bipyrrolidine‐Based Diamine‐Diphenolato and Diamine‐Diolato Ligands: Predetermination of Helical Chirality Around Tetrahedral Centres
作者:Ekaterina Sergeeva、Konstantin Press、Israel Goldberg、Moshe Kol
DOI:10.1002/ejic.201300151
日期:2013.7
conversions. Most complexes were obtained as mononuclear complexes. The least bulky Salan ligand, Lig3, led to an equilibrium between mononuclear and dinuclear complexes in noncoordinating solvents. All ligands were found to wrap around the tetrahedral zinc with very high diastereoselectivities supporting predetermined chiral induction from the bipyrrolidine core to the helical ligand wrapping. Molecular
研究了在 ZnII 周围具有 (R,R)-2,2'-联吡咯烷核心的二胺-二酚基和二胺-二元基家族的手性四齿双阴离子配体的配位化学。与二乙基锌的反应导致大多数配体的 [ONNO}Zn] 类型的配合物和二胺-diolato 配体之一的 [μ-Lig4(ZnEt)2] 类型的桥接双核配合物。与双(六甲基二硅叠氮)锌反应导致完全转化。大多数配合物是作为单核配合物获得的。体积最小的 Salan 配体 Lig3 导致单核和双核配合物在非配位溶剂中达到平衡。发现所有配体都以非常高的非对映选择性包裹四面体锌,支持从联吡咯烷核心到螺旋配体包裹的预定手性诱导。通过单晶 X 射线衍射确定的 [ONNO}Zn] 类型的两种配合物的分子结构证实了基于 (R,R) 的配体的预测 Δ 包裹。相反,围绕反式-1,2-二氨基环己烷核心组装的代表性Salan和二胺-diolato配体导致相应配合物的非对映异构体混合物。