Facilesyntheses of di- and triaza crown ethers by in tramolecular cyclization of oligoethylene glycols containing two or three imino groups or by their intermolecular cyclization with oligoethylene glycol bis(p-toluenesulfonate)s are described.
Diaza-Crown Ether-Bridged Chiral Diphosphoramidite Ligands: Synthesis and Applications in Asymmetric Catalysis
作者:Yier Luo、Guanghui Ouyang、Yuping Tang、Yan-Mei He、Qing-Hua Fan
DOI:10.1021/acs.joc.0c00223
日期:2020.6.19
A small library of diaza-crown ether-bridged chiral diphosphoramidite ligands was prepared. In the rhodium-catalyzed asymmetric hydrogenation and hydroformylation reactions, these ligands exhibited distinct properties in catalytic activity and/or enantioselectivity. Hydrogenated products with opposite absolute configurations could be obtained in high yields with excellent ee values by utilizing (S
Potentiometric and AM1d studies of the equilibria between silver(I) and diaza-15-crown and diaza-18-crown ethers with nitrogen in different positions in various solvents
acetonitrile and propylene carbonate by the potentiometric method. In two of the diaza crown ethers, AA-diaza-15 and AA-diaza-18-crown, two nitrogens in the macrocyclic ring replaced two consecutive oxygens instead of two opposite ones in the two other diaza crown ethers. It was found that complexes of 1:1 and 1:2 metal-to-ligand stoichiometry were formed. The solvent composition and cavity size of crown
A lithium ion battery separator includes a porous film of a polymeric chelating agent. The polymeric chelating agent includes a poly(undecylenyl-macrocycle), where the macrocycle is a chelating agent. A positive electrode includes a structure and a coating formed on a surface of the structure. The structure includes a lithium transition metal based active material, a binder, and a conductive carbon; and the coating includes a poly(undecylenyl-macrocycle), where the macrocycle is a chelating agent. The separator and/or positive electrode are suitable for use in a lithium ion battery.