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Your search keyword '"Patonay, Tamas"' showing total 130 results
Start Over Author "Patonay, Tamas" Publication Type Academic Journals
130 results on '"Patonay, Tamas"'

11. Synthesis of functionalized para- and meta-terphenyls based on site-selective Suzuki cross-coupling reactions of bis(triflates) of methyl 2,5-dihydroxybenzoate and methyl 2,4-dihydroxybenzoate

Author

Nawaz, Muhammad, Ullah, Ihsan, Abid, Obaid-ur-Rahman, Ali, Asad, Patonay, Tamas, Saghyan, Ashot S., Ghochikan, Tariel V., Villinger, Alexander, and Langer, Peter

Subjects
Structure-activity relationships (Biochemistry) -- Research, Chemistry
Abstract

The palladium(0)-catalyzed Suzuki cross-coupling reaction of the bis(triflates) of methyl 2,5-dihydroxybenzoate and methyl 2,4-dihydroxybenzoate afforded para- and meta-terphenyls, respectively. The reactions proceeded with very good site selectivity in favor of the sterically less hindered carbon atom. Key words: terphenyls, cross-coupling, palladium, site selectivity, Suzuki reaction. La reaction de couplage croise de Susuki des bis(triflates) de methyl 2,5-dihydroxybenzoate et de methyl 2, 4-dihydroxybenzoate catalysee au palladium(O) a donne les para-et meta-terphenyles, respectivement. Les reactions se sont deroulees avec une tres bonne selectivite de site en faveur de l'atome de carbone steriquement le moins encombre. [Traduit par la Redaction] Mots-cles: terphenyles, couplage croise, palladium, selectivite de site, reaction de Suzuki., Introduction Functionalized p-terphenyls occur in a great variety of pharmacologically relevant natural products. Examples include terphenyllin, (1) terprenin, (2) curtisian A, (3) leucomentin- (6,4) thelephorin A, (5) ganbajunin D, (6) [...]

Published
2013
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12. Chemo- and diastereoselectivity in the dimethyldioxirane oxidation of 2,3-dihydro-4H-1-benzothiopyran-4-ones and 4H-1-benzothiopyran-4-ones. Unusual reactivity of 4H-1-benzothiopyran-4-one 1-oxides

Author

Patonay, Tamas, Adam, Waldemar, Levai, Albert, Kover, Peter, Nemeth, Marta, Peters, Eva-Maria, and Peters, Karl

Subjects
Chemistry, Organic -- Research, Oxidation-reduction reaction -- Physiological aspects, Oxides -- Research, Oxygen -- Physiological aspects, Sulfones -- Physiological aspects, Biological sciences, Chemistry
Abstract

Research has been conducted on hiochromanone- and thiochromone-type substrates' dioxirane oxidation. The chemoselectivity and diastereselectivity of oxygen transfer have been investigated.

Published
2001

13. Synthesis and cyclization of 1-(2-hydroxyphenyl)-2-propen-1-one epoxides: 3-hydroxychromanones and -flavanones versus 2-(1-hydroxyalkyl)-3-coumaranones

Author

Patonay, Tamas, Levai, Albert, Nemes, Csaba, Timar, Tibor, Toth, Gabor, and Adam, Waldemar

Subjects
Organic compounds -- Synthesis, Ring formation (Chemistry) -- Research, Epoxy compounds -- Research, Carbonyl compounds -- Research, Biological sciences, Chemistry
Abstract

The cyclization of 2'-hydroxychalcone epoxides was investigated. The results showed that both alpha and beta cyclizations of the epoxides to 2-(alpha-hydroxybenzyl)-3-coumaranone and to trans-3-hydroxyflavanone, occurred under basic conditions. Likewise, extension of the method to the 1-(2-hydroxyphenyl)-2-alken-1-one epoxides obtained via DMD oxidation showed that alpha cyclization takes place with beta-unsubstituted and -monoalkylated alpha,beta-enones.

Published
1996

15. Base-promoted reactions of alpha-azido ketones with aldehydes and ketones: a novel entry to alpha-azido-beta-hydroxy ketones and 2,5-dihydro-5-hydroxyoxazoles

Author

Patonay, Tamas and Hoffman, Robert V.

Subjects
Aldehydes -- Research, Ketones -- Research, Chemical reactions -- Observations, Biological sciences, Chemistry
Abstract

The base-promoted reactions of alpha-azido ketones with aldehydes and ketones create an efficient reaction process for synthesizing either alpha-azido-beta-hydroxy ketones or 2,5-dihydro-5-hydroxyoxazoles. An aldol reaction of an aldehyde and an enolate of the alpha-azidoketone produces alpha-azido-beta-hydroxy ketones. During the electrophilic trapping of an imino anion generated by loss of nitrogen from the alpha-azido ketone enolate, 2,5-dihydro-5-hydroxyoxazoles are prepared.

Published
1995

16. Modification of hydroxybenzopyranoids: facile deoxygenation of 2, 2-dimethyl-7-hydroxy-4-chromanones and a new approach to their novel mercapto analogs

Author

Sebok, Peter, Timar, Tibor, Eszenyi, Tibor, and Patonay, Tamas

Subjects
Organic compounds -- Synthesis, Organosulfur compounds -- Research, Hydrolysis -- Analysis, Biological sciences, Chemistry
Abstract

Existing deoxygenation method helps deoxygenate a series of substituted 2,2-dimethyl-7-hydroxy-4-chromanones through their sulfonate, isourea and thiocarbamate derivatives in excellent yields. These thiocarbamates undergo hydrolysis, generating novel 2, 2-dimethyl-7-mercapto-4-chromanones. Hydrolytic side reactions inhibit the efficiency of deoxygenation of various sulfonates. While the hydrolysis of thiocarbamate derivatives yields the corresponding 2, 2-dimethyl-5-hydroxy-4-chromanone, a similar synthesis is not possible from the isourea derivatives.

Published
1994

17. Dioxirane oxidation of 3-arylideneflavanones: diastereoselective formation of trans,trans spiroepoxides from the E isomers

Author

Nemes, Csaba, Levai, Albert, Patonay, Tamas, Toth, Gabor, Boros, Sandor, Halasz, Judit, Adam, Waldemar, and Golsch, Dieter

Subjects
Ethylene oxide -- Research, Oxo compounds -- Research, Oxidation-reduction reaction -- Analysis, Epoxy compounds -- Analysis, Biological sciences, Chemistry
Abstract

Dioxirane oxidation of (E)-3-arylideneflavanones and (Z)-3-arylideneflavanones with dimethyldioxirane yields the corresponding E isomeric trans,trans spiroepoxides, diastereoselectively. The dioxirane's steric interactions with the E isomers' axial aryl group allows exclusive yield of E isomeric epoxides. The reaction of E and Z isomers with methyl(trifluoromethyl)dioxirane yields E-isomeric epoxides and decomposition products due to O2-atom transfer and radical type oxidation.

Published
1994

26. Regioselective Suzuki--Miyaura Reactions of Aromatic Bis-triflates: Electronic versus Steric Effects.

Author

Hassan, Zahid, Patonay, Tamas, and Langer, Peter

Subjects
*REGIOSELECTIVITY (Chemistry), *TRIFLATE compounds, *AROMATIC compounds, *HYDROXYLATION, *BENZENE
Abstract

Suzuki-Miyaura reactions of aromatic bis-triflates, readily available from the corresponding hydroxylated arenes, often proceed with excellent regioselectivity and provide a convenient approach to various arylated benzene derivatives, such as biphenyls, terphenyls, and arylated benzophenones, naphthalenes, xanthones, flavones, coumarins, anthraquinones, tetralones, and fluorenones. The regioselectivity is controlled by steric and electronic parameters and strongly depends on the structure of the substrates. 1 Introduction 2 Benzoates, Phthalates, and Naphthoates 3 Benzophenones and Diphenyl Sulfones 4 Xanthones and Thioxanthones 5 Flavones and Coumarins 6 Anthraquinones, Tetralones, and Fluorenones 7 Conclusion [ABSTRACT FROM AUTHOR]

Published
2013
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40. ChemInform Abstract: C-Alkynylation of Chromones by Sonogashira Reaction.

Author

Patonay, Tamas, Pazurik, Istvan, and Abraham, Anita

Subjects
*CHROMONES, *SONOGASHIRA reaction, *COUPLING reactions (Chemistry), *CARBON-carbon bonds, *RING formation (Chemistry), *PHASE-transfer catalysis
Abstract

The Sonogashira cross-coupling reaction of 2-brominated chromones is developed to yield the corresponding ethynylchromones. [ABSTRACT FROM AUTHOR]

Published
2013
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