制备并筛选了手性四齿双亚胺锌(II)配合物的动态组合库,用于(1)鉴别对映体吡啶甲酸酯和吡啶基膦酸酯过渡态类似物(TSA),以及(2)催化活性和对映选择性甲醇分解的选择性外消旋吡啶甲酸酯。锌配合物与其亚胺配体以及形成它们的醛和胺结构单元处于平衡状态,从而使文库的组成能够适应配位底物或TSA的引入。二进制(L)的Zn(OTF)(SOLV)+络合物单独地或在由手性酒石酸盐衍生的二胺(库产生的2,3)和一组N-杂环醛(4 – 12)和通过ESI-MS分析建立的配合物分布。(diimine)Zn(OTf)2复杂文库与对映异构体R-和S -2-吡啶基膦酸酯TSA 13的结合研究表明,通过形成对映异构体比率低至中等的非对映异构体LZn(R / S - 13)+络合物形成手性区分,k R / k S(α),范围从0.5到5.0;选定的二元配合物与对映体底物PyrCO 2 CH(OH)Ph(1的相应模板),手性识别率可忽略不计。几种L
Nucleophilic Substitution Catalyzed by a Supramolecular Cavity Proceeds with Retention of Absolute Stereochemistry
作者:Chen Zhao、F. Dean Toste、Kenneth N. Raymond、Robert G. Bergman
DOI:10.1021/ja508799p
日期:2014.10.15
of reactions whose stereochemicalcourse is completely reversed are exceedingly rare. We report herein a class of water-soluble host assemblies that is capable of catalyzing the substitution reaction at a secondary benzylic carbon center to give products with overall stereochemical retention, while reaction of the same substrates in bulk solution gives products with stereochemical inversion. Such ability
Selection of Chiral Zinc Catalysts for the Kinetic Resolution of Esters via Dynamic Templating
作者:R. Kannappan、K. M. Nicholas
DOI:10.1021/co3001023
日期:2013.2.11
of chiral tetradentate bis-imine zinc(II) complexes have been prepared and screened for (1) their discrimination of enantiomeric picolinate esters and pyridyl phosphonate transition state analogs (TSAs) and (2) their catalytic activity and selectivity for enantioselective methanolysis of racemic picolinate esters. The zinc complexes are in equilibrium with their imine ligands as well as with the aldehyde
制备并筛选了手性四齿双亚胺锌(II)配合物的动态组合库,用于(1)鉴别对映体吡啶甲酸酯和吡啶基膦酸酯过渡态类似物(TSA),以及(2)催化活性和对映选择性甲醇分解的选择性外消旋吡啶甲酸酯。锌配合物与其亚胺配体以及形成它们的醛和胺结构单元处于平衡状态,从而使文库的组成能够适应配位底物或TSA的引入。二进制(L)的Zn(OTF)(SOLV)+络合物单独地或在由手性酒石酸盐衍生的二胺(库产生的2,3)和一组N-杂环醛(4 – 12)和通过ESI-MS分析建立的配合物分布。(diimine)Zn(OTf)2复杂文库与对映异构体R-和S -2-吡啶基膦酸酯TSA 13的结合研究表明,通过形成对映异构体比率低至中等的非对映异构体LZn(R / S - 13)+络合物形成手性区分,k R / k S(α),范围从0.5到5.0;选定的二元配合物与对映体底物PyrCO 2 CH(OH)Ph(1的相应模板),手性识别率可忽略不计。几种L