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Journal of The Chemical Society B: Physical Organic最新文献

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The reactivity of pseudoaromatic compounds. Part IV. Normal substitutions of 2-substituted tropones by secondary or tertiary amines; abnormal behaviour of 2-fluorotropone 假芳香族化合物的反应性。第四部分:用仲胺或叔胺正常取代2-取代的tropone;2-氟醌的异常行为
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710002224
F. Pietra, F. Cima
{"title":"The reactivity of pseudoaromatic compounds. Part IV. Normal substitutions of 2-substituted tropones by secondary or tertiary amines; abnormal behaviour of 2-fluorotropone","authors":"F. Pietra, F. Cima","doi":"10.1039/J29710002224","DOIUrl":"https://doi.org/10.1039/J29710002224","url":null,"abstract":"2-Fluorotropone reacts with piperidine in benzene to give 2-piperidinotropone quantitatively. Experiments with 2-fluoro[3,5,7-2H3]tropone show normal substitution of fluorine by the nitrogen atom of piperidine. A kinetic investigation shows (i) that this reaction is of overall second-order (first-order with respect to both reagents) and (ii) that the free energy of activation is 4–5 kcal mol–1 lower than the corresponding values found for 2-chloro-, 2-bromo-, 2-iodo-, and 2-methoxy-tropone. Clearly, the reaction does not follow the isokinetic relationship observed for the other tropones. The behaviour of 2-fluorotropone towards quinuclidine depends on the solvent; in dimethyl sulphoxide, substitution of fluorine by quinuclidine gives 1-{2-[N-oxocyclohepta-1,3,5-trien-1-yl)-piperidin-4-yl]ethyl}-1-azoniabicyclo[2,2,2]octane fluoride at a rate comparable to that for similar reaction of 2-iodo- or 2-chloro-tropone, but in benzene at room temperature 2-fluorotropone does not react with quinuclidine unlike the chloro- or iodo-compound. Under reflux, only intractable tars are obtained.1-Halogeno-2,4-dinitrobenzenes behave similarly; they undergo clean substitution of the halogen atom by protic amines in both dimethyl sulphoxide and benzene. However, the fluoro-compound is unreactive towards quinuclidine whereas under similar conditions the chloro-compound gives 1-{2-[N-(2,4-dinitrophenyl)piperidin-4-yl]ethyl}-1-azoniabicyclo[2,2,2]octane chloride. Under forcing conditions piperidinium 2,4-dinitrophenolate is formed by hydrolysis (due to moisture) of 1-fluoro-2,4-dinitrobenzene. Intramolecular base catalysis by the ‘carbonyl’ oxygen atom is suggested as the basis of the isokinetic relationship in the reactions of the troponoid system with protic amines, and the observed data are consistent with this hypothesis.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74143057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
Mechanisms of antioxidant action: the pro-oxidant stage in the function of thiodipropionate esters as antioxidants 抗氧化作用机制:硫代二丙酸酯抗氧化作用的促氧化阶段
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710001747
C. Armstrong, G. Scott
{"title":"Mechanisms of antioxidant action: the pro-oxidant stage in the function of thiodipropionate esters as antioxidants","authors":"C. Armstrong, G. Scott","doi":"10.1039/J29710001747","DOIUrl":"https://doi.org/10.1039/J29710001747","url":null,"abstract":"The thermal decomposition of dimethyl sulphinyldipropionate alone and in the presence of 2,6-di-t-butyl-α-(3,5-di-t-butyl-4-oxo-2,5-cyclohexadiene-1-ylidene)p-tolyloxy (Galvinoxyl) was studied. Results show that radical intermediates capable of initiating oxidations are not produced under these conditions but radicals are formed from dimethyl sulphinyldipropionate in the presence of hydroperoxides. This reaction is probably responsible for the pro-oxidant effects associated with sulphoxides.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75164123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
The stereochemistry of 2-alkoxy-4-methyl-1,3,2-dioxaphosphorinans 2-烷氧基-4-甲基-1,3,2-二磷苷的立体化学
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710001136
C. Bodkin, P. Simpson
{"title":"The stereochemistry of 2-alkoxy-4-methyl-1,3,2-dioxaphosphorinans","authors":"C. Bodkin, P. Simpson","doi":"10.1039/J29710001136","DOIUrl":"https://doi.org/10.1039/J29710001136","url":null,"abstract":"The stereochemistry of a series of 2-alkoxy-4-methyl-1,3,2-dioxaphosphorinans has been investigated by n.m.r. and dipole-moment studies. For a given alkoxy-group (MeO, EtO, or PriO), the more-stable member of the isomeric pair adopts a chair conformation, having the trans-configuration, with equatorial methyl and axial alkoxy-group. The less-stable isomers, having the cis-configuration, adopt rapidly flipping chair conformations. Configurational stability is solvent dependent.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75435242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
Reactions of carbonyl compounds in basic solutions. Part II. The mechanism of the alkaline hydrolysis of methyl 2-benzoylbenzoates 羰基化合物在碱性溶液中的反应。第二部分。2-苯甲酰苯甲酸甲酯的碱性水解机理
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710000145
K. Bowden, G. R. Taylor
{"title":"Reactions of carbonyl compounds in basic solutions. Part II. The mechanism of the alkaline hydrolysis of methyl 2-benzoylbenzoates","authors":"K. Bowden, G. R. Taylor","doi":"10.1039/J29710000145","DOIUrl":"https://doi.org/10.1039/J29710000145","url":null,"abstract":"Rate coefficients have been measured for the alkaline hydrolysis of methyl 3′- and 4′-substituted 2-benzoylbenzoates in 70%(v/v) dioxan–water at 30 °C. The pKa values of the corresponding acids have been measured in 80%(w/w) 2-methoxyethanol–water at 25 °C. The effects of substitution have been assessed by means of the Hammett equation. Comparison of the reaction constants obtained with those for the reference systems, benzoic acids and their methyl esters, indicates clearly that, in the alkaline hydrolysis of the methyl 2-benzoylbenzoates, the rate-determining step involves direct or pre-equilibrium attack at the keto-carbonyl group.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75824761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
Mechanism of oxidations by chloramine-T. Part I. Oxidation of α-hydroxy-acids 氯胺- t氧化机理。第一部分α-羟基酸的氧化
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710001712
S. P. Mushran, M. C. Agrawal, B. Prasad
{"title":"Mechanism of oxidations by chloramine-T. Part I. Oxidation of α-hydroxy-acids","authors":"S. P. Mushran, M. C. Agrawal, B. Prasad","doi":"10.1039/J29710001712","DOIUrl":"https://doi.org/10.1039/J29710001712","url":null,"abstract":"Kinetics of the osmium(VIII)-catalysed oxidation of glycollic, lactic, and mandelic acids have been investigated in alkaline media. First-order rate plots in chloramine-T were linear up to two half-lives. However, under pseudo-first-order conditions the rate constants showed a slight decrease with increase in chloramine-T concentration. The rate of reaction was independent of α-hydroxy-acid concentration and directly proportional to the osmium-(VIII) and the reciprocal of the hydroxide ion concentrations. The formation of a complex between N-chlorotoluene-p-sulphonamide and osmium(VIII) is rate-determining and is followed by the rapid transfer of a hydride ion from the substrate to this complex.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75866502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 15
Kinetics of oxidation of ethyl mandelate by chromic acid 铬酸氧化扁桃酸乙酯的动力学研究
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710001166
D. Jha, G. V. Bakore
{"title":"Kinetics of oxidation of ethyl mandelate by chromic acid","authors":"D. Jha, G. V. Bakore","doi":"10.1039/J29710001166","DOIUrl":"https://doi.org/10.1039/J29710001166","url":null,"abstract":"Oxidation of ethyl mandelate with chromic acid is of the first order with respect to oxidant, ester, and hydrogen ions. The thermodynamic parameters for oxidation have been evaluated. The hydrolysis under similar conditions is slower than oxidation. The main product of oxidation is Ph·CO·CO2Et. The rate of hydrolysis and products rule out the possibility of hydrolysis before oxidation. A mechanism involving C–H bond rupture in the rate-determining step has been suggested.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75882470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
The kinetics and mechanism of the electrophilic substitution of heteroaromatic compounds. Part XXV. The acid-catalysed hydrogen-exchange of some 2-aminopyridine derivatives 杂芳烃化合物亲电取代的动力学和机理。第二十五章部分。一些2-氨基吡啶衍生物的酸催化氢交换
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710002363
A. El-Anani, P. Jones, A. Katritzky
{"title":"The kinetics and mechanism of the electrophilic substitution of heteroaromatic compounds. Part XXV. The acid-catalysed hydrogen-exchange of some 2-aminopyridine derivatives","authors":"A. El-Anani, P. Jones, A. Katritzky","doi":"10.1039/J29710002363","DOIUrl":"https://doi.org/10.1039/J29710002363","url":null,"abstract":"Rate profiles are reported for hydrogen exchange at the 3-position for 2-amino-5-chloropyridine, 5-chloro-2-dimethylaminopyridine, and 2-amino-5-bromopyridine 1-oxide and for exchange at the 5-position for 2-amino-3-methylpyridine.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73242316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Ultraviolet absorption and protonation equilibria of amino- and nitro-substituted pyridines 氨基和硝基取代吡啶的紫外吸收和质子化平衡
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710002034
I. R. Bellobono, G. Favini
{"title":"Ultraviolet absorption and protonation equilibria of amino- and nitro-substituted pyridines","authors":"I. R. Bellobono, G. Favini","doi":"10.1039/J29710002034","DOIUrl":"https://doi.org/10.1039/J29710002034","url":null,"abstract":"Solvent effects on the bathochromic shift in the first π–π* band of aminonitropyridines were examined. They were interpreted in terms of inter- and intra-molecular hydrogen bonding, as well as of transition polarizability which determines solvatochromism. All possible dissociation constants of conjugate acids of amino-, diamino-, nitro-, and aminonitro-pyridines have also been measured at 25°C by spectrophotometric determination of acid–base concentration ratios. The influence of amino- and nitro-groups in the pyridine ring on pKa1 and pKa2 was discussed on the basis of electrical characteristics of substituents and electron availability of reaction site.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73265936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
Nucleophilic attack on 4-aminomethyleneoxazol-5(4H)-ones, a rationalisation of penicillin carcinogenicity 对4-氨基甲基恶唑-5(4H)- 1的亲核攻击，青霉素致癌性的合理化
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710000848
J. Longridge, D. Timms
{"title":"Nucleophilic attack on 4-aminomethyleneoxazol-5(4H)-ones, a rationalisation of penicillin carcinogenicity","authors":"J. Longridge, D. Timms","doi":"10.1039/J29710000848","DOIUrl":"https://doi.org/10.1039/J29710000848","url":null,"abstract":"4-Aminomethyleneoxazol-5(4H)-ones are shown to undergo nucleophilic attack at the methylene carbon on the side chain rather than at the ring carbonyl group. Penicillenic acid, formerly reported to react exclusively at the carbonyl, follows this general pattern when intramolecular nucleophilic attack by the thiol group is inhibited, a reaction of possible importance in penicillin carcinogenicity.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78447422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
The photochemistry of 4-phenylbut-1-ene 4-苯基丁烯的光化学性质
Journal of The Chemical Society B: Physical Organic Pub Date : 1971-01-01 DOI: 10.1039/J29710000931
K. Salisbury
{"title":"The photochemistry of 4-phenylbut-1-ene","authors":"K. Salisbury","doi":"10.1039/J29710000931","DOIUrl":"https://doi.org/10.1039/J29710000931","url":null,"abstract":"Photolysis of 4-phenylbut-1-ene in the gas phase results in the formation of benzylcyclopropane, trans-phenyl-methylcyclopropane, and trans-1-phenylbut-2-ene. By the use of butene, piperylene, and neopentane quenching experiments and by fluorescence measurements, the formation of the products is shown to occur via the triplet manifold and to involve a common vibrationally excited intermediate. In solution 4-phenylbut-1-ene produces no new monomeric compound on excitation in the aromatic absorption band.","PeriodicalId":17268,"journal":{"name":"Journal of The Chemical Society B: Physical Organic","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1971-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77256948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
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