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Lorincz K.,Eotvos Lorand University | Kotschy A.,Servier Research Institute of Medicinal Chemistry | Tammiku-Taul J.,University of Tartu | Sikk L.,University of Tartu | Burk P.,University of Tartu
Journal of Organic Chemistry | Year: 2010

Figure presented. The possible reaction pathways between methyllithium and disubstituted 1,2,4,5-tetrazines (bearing methyl, methylthio, phenyl, and 3,5-dimethylpyrazolyl groups) were investigated by means of the density functional theory B3LYP/6-31G* method. Solvation was modeled using the supermolecule approach, adding one tetrahydrofuran molecule to the complexes. Comparison of the calculated energies and structures for the alternate azaphilic and nucleophilic addition pathways showed that the azaphilic addition is kinetically favored over nucleophilic addition, while thermodynamically the nucleophilic addition is usually preferred. The coordination of the tetrazine molecule with methyllithium was found to play a crucial role in the process. These findings provide the first rationale for the experimentally observed unique reactivity of tetrazines toward polar organometallic reagents, suggesting the presence of a kinetically controlled process. © 2010 American Chemical Society. Source


Faigl F.,Budapest University of Technology and Economics | Faigl F.,Hungarian Academy of Sciences | Erdelyi Z.,Budapest University of Technology and Economics | Deak S.,Budapest University of Technology and Economics | And 2 more authors.
Tetrahedron Letters | Year: 2014

A highly efficient pyrrolidine-derived atropisomeric amino alcohol, (Sa)-1-[2-diphenylhydroxymethyl-6-(trifluoromethyl)phenyl]-2-(1-pyrrolido)methyl-1H-pyrrole, has been synthesized as a chiral ligand for the enantioselective addition of diethylzinc to some prochiral aldehydes to afford (S)-alcohols. The conversion rates were close to quantitative with good to excellent enantiomeric excesses (up to 95% ee). © 2014 Elsevier Ltd. All rights reserved. Source


Deak S.,Budapest University of Technology and Economics | Matravolgyi B.,Hungarian Academy of Sciences | Feczku G.,Budapest University of Technology and Economics | Erdelyi Z.,Budapest University of Technology and Economics | And 3 more authors.
Tetrahedron Asymmetry | Year: 2015

Abstract The synthesis of new, trifluoromethyl group containing atropisomeric amino alcohols and their application in enantioselective diethylzinc additions to aldehydes is described. A significant improvement of the enantioinductive effects of the new ligands by increasing the Brønsted acidity and bulkiness of the triarylcarbinol moiety is also reported. Tuning was achieved by the introduction of phenyl substituents containing two trifluoromethyl groups onto the α-carbon of the tertiary alcohol part of the ligand. The application of the new catalysts provided 1-(substituted phenyl)propanols with excellent enantiomeric purities. © 2015 Elsevier Ltd. Source


Sinai A.,Institute for Research In Catalysis | Vangel D.,Institute for Research In Catalysis | Gati T.,Servier Research Institute of Medicinal Chemistry | Bombicz P.,Hungarian Academy of Sciences | Novak Z.,Institute for Research In Catalysis
Organic Letters | Year: 2015

A copper-catalyzed carboarylation-ring-closure strategy was used for the modular synthesis of oxazolines via the reaction of 1-aryl- and 1-alkylpropargylamides and diaryliodonium salts. The novel approach enables the efficient, modular synthesis of oxazoline derivatives bearing fully substituted exo double bonds. © 2015 American Chemical Society. Source


Faigl F.,Budapest University of Technology and Economics | Faigl F.,Hungarian Academy of Sciences | Deak Sz.,Budapest University of Technology and Economics | Erdelyi Zs.,Budapest University of Technology and Economics | And 4 more authors.
Chirality | Year: 2015

Efficient synthesis of several new atropisomeric amino alcohols having 1-phenyl-1H-pyrrole skeleton are reported. Steric arrangements of the products were confirmed by a single-crystal X-ray measurement. The consequences of the size of the N-substituents on enantioinduction were examined by employing the enantioselective catalytic addition of diethylzinc to a series of substituted benzaldehydes (yields 91-97%, up to 85% enantiomeric excess). The special effect of the ortho methoxy group of the substrate on the enantioinduction is also interpreted. © 2014 Wiley Periodicals, Inc. Source

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