Synthesis and computation of diastereomeric phenanthrolineequinine ligands and their application in asymmetric Henry reaction (original) (raw)

Synthesis of novel thiophene-based chiral ligands and their application in asymmetric Henry reaction

Novel chiral thiolated amino alcohols were synthesized from norephedrine and thiophene carbaldehydes (methyl-or ethyl-substituted) and applied to the catalytic asymmetric Henry reaction of various aldehydes with nitromethane to provide b-hydroxy nitroalkanols in high conversion (92%). The reaction was optimized in terms of the metal, solvent, temperature and amount of chiral ligand. The corresponding catalyst with Cu(OTf) 2 and 2-propanol as the solvent provided the best enantioselectivities (up to 96% ee) of the corresponding nitroalcohols for aliphatic aldehydes.

Asymmetric Henry reactions catalyzed by metal complexes of chiral oxazoline based ligands

Chiral oxazolines have been synthesized from norephedrine and pyrrole nitrile or benzoyl chloride and applied to the catalytic asymmetric Henry reactions of p-nitro aldehydes with nitromethane to provide b-hydroxy nitroalkanols in high conversion (up to 92%). The reaction was then optimized in terms of the metal, solvent, temperature, and amount of chiral ligand. The corresponding catalyst with Cu(OTf) 2 and isopropanol as the solvent gave the best enantioselectivities (up to 84% ee) of the corresponding b-nitroalkanol for p-nitrobenzaldehyde.

Cu (II)-catalyzed asymmetric henry reaction with a novel C1-symmetric aminopinane-derived ligand

Molecules (Basel, Switzerland), 2015

A novel C1-symmetric dinitrogen ligand was synthesized in high yield from commercially available (1R,2R,3R,5S)-(-)-isopinocampheylamine and 1-methyl-2-imidazolecarboxaldehyde. In combination with Cu(OAc)2H2O, this new ligand promote the reaction between nitromethane and aliphatic aldehydes with high yields (up to 97%) and moderate enantioselectivities (up to 67% ee). The reactions with benzaldehyde required prolonged reaction time that resulted in diminished yields, but accompanied with ee-values in the 55%-76% range.

Chiral phenanthrolines as ligands for Cu(I)-catalyzed asymmetric allylic oxidation

Journal of Molecular Catalysis A-chemical, 2003

A number of chiral 1,10-phenanthrolines (phens) have been assessed in asymmetric Cu(I)-catalyzed allylic oxidation of cyclohexene. Very effective copper-phen catalysts are obtained only when these ligands bear at least a substituent close to the reactive site of the catalyst. Enantioselectivity up to 36% was obtained.

Salicylaldimine based copper (II) complex-potential catalyst for asymmetric Henry reaction

Arkivoc, 2011

The chiral ligand synthesized from L-diphenylvalinol and salicylaldehyde is found to catalyse the asymmetric Henry reaction with copper(II)acetate monohydrate. Various nitroaldols were formed with 77-95% ee and good yield. The mechanism for the formation of a particular enantiomer is also discussed. The enantioselection in the formation of the chiral nitroaldol is discussed in terms of steric bulkiness of the catalytic system.

Synthesis and Applications of Asymmetric Catalysis Using Chiral Ligands Containing Quinoline Motifs

SynOpen, 2022

In the past decade, asymmetric synthesis of chiral ligands containing quinoline motifs, a family of natural products displaying a broad range of structural diversity and their metal complexes, have become the most significant methodology for the generation of enantiomerically pure compounds of biological and pharmaceutical interest. This review provides comprehensive insight on the plethora of nitrogen-based chiral ligands containing quinoline motifs and organocatalysts used in asymmetric synthesis. However, it is confined to the synthesis of quinoline-based chiral ligands and metal complexes, and their applications in asymmetric synthesis as homogeneous and heterogeneous catalysts.1 Introduction2 Synthesis of Chiral Ligands Containing Quinoline Motifs2.1 Synthesis of Schiff Base Type Chiral Ligands2.2 Synthesis of Oxazolinyl-Type Chiral Ligands2.3 Synthesis of Chiral N,N-Type Ligands2.4 Synthesis of Amine-Based Chiral Ligands2.5 Synthesis of P,N-Type Chiral Ligands2.6 Synthesis of ...