Search Results - "Felfoldi, Karoly"

New data on the effect of steric constraints on the chiral induction in the Orito reaction: Hydrogenation of activated steroid ketones by Szőri, Kornél, Balázsik, Katalin, Felföldi, Károly, Bucsi, Imre, Cserényi, Szabolcs, Szöllősi, György, Vass, Elemér, Hollósi, Miklós, Bartók, Mihály

“…After optimization of the experimental conditions, the Orito reaction may be rendered suitable for the asymmetric hydrogenation of activated steroid ketones. ▪…”
Get full text

Up to 96% Enantioselectivities in the Hydrogenation of Fluorine Substituted (E)-2,3-Diphenylpropenoic Acids over Cinchonidine-Modified Palladium Catalyst by Szollosi, Gyorgy, Herman, Beata, Felfoldi, Karoly, Fulop, Ferenc, Bartok, Mihaly

“…The enantioselective hydrogenation of methoxy‐ and fluorine‐substituted (E)‐2,3‐diphenylpropenoic acid derivatives was studied over cinchonidine‐modified,…”
Get full text

Effect of the substituent position on the enantioselective hydrogenation of methoxy-substituted 2,3-diphenylpropenoic acids over palladium catalyst by SZÖLLÖSI, György, HERMAN, Beata, FELFÖLDI, Karoly, FÜLÖP, Ferenc, BARTOK, Mihaly

“…The position of the methoxy substituent has crucial influence on the enantioselective hydrogenation of the methoxy-substituted 2,3-diphenylpropenoic acids over…”
Get full text

Enantioselective hydrogenation of ethyl pyruvate catalyzed by α- and β-isocinchonine-modified Pt/Al2O3 in acetic acid by BARTOK, Mihaly, SUTYINSZKI, Maria, FELFÖLDI, Karoly

Get full text

Enantioselective hydrogenation of ethyl pyruvate catalyzed by α- and β -isocinchonine -modified Pt/Al2O3 in toluene : inversion of enantioselectivity by BARTOK, Mihaly, SUTYINSZKI, Maria, BUCSI, Imre, FELFÖLDI, Karoly, SZÖLLÖSI, György, BARTHA, Ferenc, BARTOK, Tibor

Get full text

Enantioselective hydrogenation of propenoic acids bearing heteroaromatic substituents over cinchonidine modified Pd/alumina by Hermán, Beáta, Szőllősi, György, Felföldi, Károly, Fülöp, Ferenc, Bartók, Mihály

“…The hydrogenation of two 2,3-diarylpropenoic acids bearing heteroaromatic substituents, i.e. ( E)-2-phenyl-3-(2-furyl)propenoic acid and (…”
Get full text

Study of enantioselective hydrogenation of bulky esters of phenylglyoxylic acid on Pt-CD and Pt- β-ICN chiral catalysts: Steric effect of ester groups and inversion of enantioselectivity by SZORI, Kornél, BALAZSIK, Katalin, FELFÖLDI, Karoly, BARTOK, Mihaly

“…Enantioselective hydrogenation of seven different esters of phenylglyoxylic acid was investigated by variation of the bulkiness at ester side of the substrates…”
Get full text

C9-O-substituted derivatives of cinchona alkaloids as chiral modifiers in the Orito-reaction: Effects of structure of modifiers on sense of enantioselectivity by Cserényi, Szabolcs, Felföldi, Károly, Balázsik, Katalin, Szöllősi, György, Bucsi, Imre, Bartók, Mihály

“…In hydrogenation of ethyl pyruvate when the bulk of X was increased, the enantioselectivity not only decreased, but inversion also took place dependent on…”
Get full text

Heterogeneous asymmetric reactions. Part 17: Asymmetric hydrogenation of 2-methyl-2-pentenoic acid over cinchona modified Pd/Al2O3 catalysts by KUN, Istvan, TÖRÖK, Bela, FELFÖLDI, Karoly, BARTOK, Mihaly

Get full text

Enantioselective hydrogenation of trifluoromethylcyclohexyl ketone on cinchona alkaloid modified Pt-alumina catalyst by FELFÖLDI, Karoly, VARGA, Tibor, FORGO, Péter, BARTOK, Mihaly

“…The enantioselective heterogeneous catalytic hydrogenation of trifluoromethylcyclohexyl ketone (2), on Pt-alumina (E4759) modified by different chiral…”
Get full text

Preparation of 3-substituted and 2,3-disubstituted-4,4,4-trifluoro-2-butenoic acids—Perkin condensation of activated aromatic ketones by Cserényi, Szabolcs, Felföldi, Károly, Forgo, Peter, Pálinkó, István

“…Stereoisomeric CF 3-substituted cinnamic acid derivatives have been prepared via the Perkin reaction using activated aromatic ketones. ▪ The Perkin reaction of…”
Get full text

Heterogeneous asymmetric reactions: Part 32. High enantioselectivities in the hydrogenation of activated ketones on cinchona alkaloid modified platinum-alumina catalysts by Felföldi, Károly, Balázsik, Katalin, Bartók, Mihály

“…The modifier concentration dependence of rate and enantioselectivity (ee) was investigated of the diethyl-2-oxoglutarate (EOG) and pyruvaldehyde dimethyl…”
Get full text

Heterogeneous asymmetric reactions 20. Effect of ultrasonic variables on the enantiodifferentiation in cinchona-modified platinum-catalyzed sonochemical hydrogenations by TÖRÖK, Béla, BALAZSIK, Katalin, TÖRÖK, Marianna, FELFÖLDI, Karoly, BARTOK, Mihaly

“…The effect of sonochemical variables on a cinchona alkaloid modified Pt/Al2O3 catalyst system and its application in α-ketoester hydrogenation are described…”
Get full text

Heterogeneous asymmetric reactions. 29. Enantioselective hydrogenation of ethyl benzoylformate over dihydrocinchonidine-modified platinum-alumina catalyst in acetic acid by SUTYINSZKI, Maria, SZÖRI, Kornél, FELFÖLDI, Karoly, BARTOK, Mihaly

“…The enantioselective hydrogenation of ethyl benzoylformate to (R)-ethyl mandelate over dihydrocinchonidine (DHCD)-modified Pt/Al2O3 catalyst in acetic acid was…”
Get full text

Preparation of new 2,3-diphenylpropenoic acid esters - good yields even for the more hindered Z isomers by Boros, László, Felföldi, Károly, Pálinkó, István

“…The potassium salt of E- and Z-2,3-diphenylpropenoic acids prepared in situ could be esterified efficiently in DMSO with the appropriate alkyl halides at room…”
Get full text

Structural characterization of acetylpyridinium-ethyl pyruvate adducts by electrospray ionization mass spectrometry by BARTOK, Mihaly, BANOK, Tibor, SZÖLLÖSI, György, FELFÖLDI, Karoly

“…The reactions of ethyl pyruvate with acetic anhydride and pyridine were studied by electrospray ionization mass spectrometry (ESI‐MS). Ethyl…”
Get full text

98% Enantioselectivity in the asymmetric synthesis of a useful chiral building block by heterogeneous method: Enantioselective hydrogenation of ethyl-benzoylformate over cinchona modified Pt/Al2O3 catalysts in the acetic acid by Sutyinszki, Mária, Szöri, Kornél, Felföldi, Károly, Bartók, Mihály

Get full text

Heterogeneous asymmetric reactions. Part 38. Enantioselective hydrogenation of fluoroketones on Pt-alumina catalyst: JMCA Special Issue on Chiral Heterogeneous Catalysis by VARGA, Tibor, FELFÖLDI, Karoly, FORGO, Péter, BARTOK, Mihaly

Get full text

Heterogeneous asymmetric reactions: Part 38. Enantioselective hydrogenation of fluoroketones on Pt–alumina catalyst by Varga, Tibor, Felföldi, Károly, Forgó, Péter, Bartók, Mihály

“…We investigated the enantioselective heterogeneous hydrogenation of some fluoroketones, e.g. 4-(trifluoroacetyl)biphenyl (max. 67% ee), on modified Pt–alumina…”
Get full text

Enantioselective hydrogenation of fluorinated unsaturated carboxylic acids over cinchona alkaloid modified palladium catalysts by Szőllősi, György, Varga, Tibor, Felföldi, Károly, Cserényi, Szabolcs, Bartók, Mihály

“…The hydrogenation of trifluoromethyl substituted prochiral α,β-unsaturated carboxylic acids has been studied over cinchona alkaloid modified palladium…”
Get full text