Diaza-Crown Ether-Bridged Chiral Diphosphoramidite Ligands: Synthesis and Applications in Asymmetric Catalysis
Yi‐Er Luo, Guanghui Ouyang, Yuping Tang, Yan‐Mei He, Qing‐Hua Fan
Abstract
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,S)-L1 and (S,S)-L3, respectively. Meanwhile, the addition of alkali metal cations caused variations in catalytic outcomes, showing the supramolecular tunability of these Rh/diphosphoramidite catalytic systems.
Topics & Concepts
HydroformylationCrown etherCatalysisRhodiumChemistryEtherAsymmetric hydrogenationSupramolecular chemistryAlkali metalMetalEnantioselective synthesisPolymer chemistryCombinatorial chemistryOrganic chemistryMoleculeIonAsymmetric Hydrogenation and CatalysisSurface Chemistry and CatalysisChemical Synthesis and Analysis