81643-05-2Relevant academic research and scientific papers
Diastereoselection and induced chirality at-metal in distorted-tetrahedral bis[(R or S)-1-(p-R1-C6H4)-N-(phenyl(pyridin-2-yl)methylene)ethanamino-κ2 N,N]-Δ/Λ-copper(PF6)2
Bindu, Mortuza Mamun,Enamullah, Mohammed,Hossain, Mohammad Anwar,Islam, Mohammad Khairul,Zaman, Mohammad Al-Moktadir
, p. 1 - 20 (2020)
The enantiopure Schiff bases (R or S)-1-(p-R1-C6H4)-N-(phenyl(pyridin-2-yl)methylene)ethanamine (R1 = H and OCH3) are synthesized from reaction between the 2-benzoyl-pyridine and chiral-amine (R or S)-1-(p-R1-C6H4)ethylamine, respectively. These Schiff bases react with the copper(II) acetate to give distorted-tetrahedral bis[(R or S)-1-(p-R1-C6H4)-N-(phenyl(pyridin-2-yl)methylene)ethanamino-κ2 N,N]-Δ/Λ-Cu(PF6)2 in the presence of NH4PF6. A conformational change from cis- to trans-isomer occurs in solution and thereby, the copper(II) coordinates to the solely trans-form to provide the complexes. Cyclic voltammograms demonstrate two quasi-reversible one electron charge transfer processes for the Cu2+/Cu+ and Cu+/Cu0 couples in acetonitrile. ECD spectra reveal expected mirror-image relationships and indicate enantiopurity or enantiomeric excess of the R or S-ligands and their associated complexes in solution. Comparisons of experimental and simulated ECD spectra suggest induced chirality at-metal center, which diastereoselectively provides the Δ-Cu-R or Λ-Cu-S diastereomer as major product in solution. DFT/TDDFT optimized structures and excited state properties correspond well to the experimental results.
Enantioselective Friedel-Crafts alkylation of indole derivatives catalyzed by new Yb(OTf)3-pyridylalkylamine complexes as chiral Lewis acids
Grach, Guillaume,Dinut, Aurelia,Marque, Sylvain,Marrot, Jerome,Gil, Richard,Prim, Damien
experimental part, p. 497 - 503 (2011/02/28)
New Yb(OTf)3-pyridylalkylamine complexes have been employed as chiral Lewis acids in the enantioselective Friedel-Crafts alkylation of indole derivatives with trifluoropyruvates. The influence of the substituents as well as the configuration of
Asymmetric Catalyses, 14. Enantioselective Hydrosilylation of Prochiral Ketones with Rh- and Pt-Complexes of Optically Active N-Chelate Ligands
Brunner, Henri,Reiter, Barbara,Riepl, Georg
, p. 1330 - 1354 (2007/10/02)
N-chelate ligands with a lateral chiral center, which derive from optically active primary amines, amino acids, and amino acid derivatives, catalyze in Rh and Pt complexes the enantioselective hydrosilylation of acetophenone, benzyl methyl ketone, and tert-butyl methyl ketone with diphenyl- and 1-naphthylphenylsilane.The ketones are transformed into the corresponding silyl ethers which on hydrolysis yield the alcohols 1-phenylethanol, 1-phenyl-2-propanol and 3,3-dimethyl-2-butanol. 37 N ligands 1 - 37 with 2 (I) and K (XX) as well as 21 isolated complexes II - XIX and XXI - XXIII are tested.The best optical inductions exceed considerably those which were obtained with optically active phosphane containing catalysts used up to now.
