- Copper-catalyzed aerobic C-C bond cleavage of lactols with N-hydroxy phthalimide for synthesis of lactones
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The transformation of cyclic hemiacetals (lactols) into lactones has been achieved by Cu-catalyzed aerobic C-C bond cleavage in the presence of N-hydroxy phthalimide (NHPI). The present process is composed of a multistep sequence including a) formation of exo-cyclic enol ethers by dehydration; b) addition of phthalimide N-oxyl radical to the enol ethers followed by trapping of the resulting C-radicals with molecular oxygen to form peroxy radicals; c) reductive generation of oxy radicals and subsequent β-radical fragmentation to generate lactones.
- Tnay, Ya Lin,Chiba, Shunsuke
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Read Online
- Decarboxylative Amination: Diazirines as Single and Double Electrophilic Nitrogen Transfer Reagents
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The ubiquity of nitrogen-containing small molecules in medicine necessitates the continued search for improved methods for C-N bond formation. Electrophilic amination often requires a disparate toolkit of reagents whose selection depends on the specific structure and functionality of the substrate to be aminated. Further, many of these reagents are challenging to handle, engage in undesired side reactions, and function only within a narrow scope. Here we report the use of diazirines as practical reagents for the decarboxylative amination of simple and complex redox-active esters. The diaziridines thus produced are readily diversifiable to amines, hydrazines, and nitrogen-containing heterocycles in one step. The reaction has also been applied in fluorous phase synthesis with a perfluorinated diazirine.
- Chandrachud, Preeti P.,Wojtas, Lukasz,Lopchuk, Justin M.
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supporting information
p. 21743 - 21750
(2021/01/11)
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- PPh3/I2/HCOOH: An efficient CO source for the synthesis of phthalimides
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A straightforward and general method has been developed for the synthesis of phthalimide derivatives from 2-iodobenzamides and PPh3/I2/HCOOH in the presence of a catalytic amount of Pd(OAc)2. The reaction results demonstrate that PPh3/I2/HCOOH is a facile, efficient and safe CO source. The whole process is carried out in toluene at 80 °C and furnishes the desired products in good to excellent yields.
- Wang, Yingying,Zhou, Yang,Lei, Min,Hou, Jinjun,Jin, Qinghao,Guo, Dean,Wu, Wanying
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supporting information
p. 1180 - 1185
(2019/01/26)
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- Methyl esters of 2-(N-hydroxycarbamimidoyl)benzoyl-substituted α-amino acids as promising building blocks in peptidomimetic synthesis: a comparative study
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Abstract: An efficient and simple synthetic protocol for the synthesis of a number methyl esters of 2-(N-hydroxycarbamimidoyl)benzoyl-substituted (S)-α-amino acids via subsequent coupling and hydroxyamination of 2-cyanobenzamide derivatives has been developed. Comparative analysis of three pseudopeptide series based on 2-cyano- and 2-amidoxime-substituted benzoic acid and its pyridine and pyrazine counterparts has been provided and it has revealed a practical advantage of the benzoic acid derivatives due to their greater availability. The impact of the nitrogen atom in the aromatic ring on the trans/cis-amide equilibrium in the proline derivatives is discussed. Graphical abstract: [Figure not available: see fulltext.]
- Tkachuk, Volodymyr A.,Hordiyenko, Olga V.,Omelchenko, Irina V.,Medviediev, Volodomir V.,Arrault, Axelle
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p. 2293 - 2309
(2018/11/02)
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- A Novel Green Synthesis of Thalidomide and Analogs
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Thalidomide and its derivatives are currently under investigation for their antiangiogenic, immunomodulative, and anticancer properties. Current methods used to synthesize these compounds involve multiple steps and extensive workup procedures. Described herein is an efficient microwave irradiation green synthesis method that allows preparation of thalidomide and its analogs in a one-pot multicomponent synthesis system. The multicomponent synthesis system developed involves an array of cyclic anhydrides, glutamic acid, and ammonium chloride in the presence of catalytic amounts of 4-N,N-dimethylaminopyridine (DMAP) to produce thalidomide and structurally related compounds within minutes in good isolated yields.
- Benjamin, Ellis,Hijji, Yousef M.
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- Spectroscopic and analysis of the hydrolytic process of folpet and its interaction with DNA
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Hydrolysis of the pesticide folpet [N-(trichloromethylthio) phthalimide] in aqueous solution in the absence or presence of calf thymus DNA (ctDNA) was investigated using UV-Vis absorption spectroscopy, and the interactions of folpet and its hydrolyzates with ctDNA were determined by fluorescence and circular dichroism spectroscopy, coupled with viscosity and melting temperature measurements. The absorption spectra data was further analyzed by alternate least squares, a chemometrics method, and the concentration profiles of the reacting species (folpet, unstable intermediate, phthalimide and phthalic acid) and their pure component spectra were simultaneously extracted to monitor the hydrolytic process. It was found that the hydrolytic process consists of at least two steps, generation of an unstable intermediate and production of its end hydrolyzates, phthalimide and phthalic acid. Addition of ctDNA significantly affects the hydrolysis of folpet. The results from the competitive binding with intercalator ethidium bromide, ctDNA melting and viscosity measurements, and circular dichroism studies indicate that folpet and the intermediate can intercalate into the double-helix of DNA, phthalic acid is bound to DNA by a partial intercalation, while phthalimide does not show binding to ctDNA. Moreover, the binding of folpet (or the intermediate) and phthalic acid to ctDNA induced structural changes of the DNA.
- Zhang, Yepeng,Zhang, Guowen
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p. 1388 - 1401
(2014/12/10)
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- Electrochemical reduction of N,N′-thiobisphthalimide and N,N′-dithiobisphthalimide: Ejection of diatomic sulfur through an autocatalytic mechanism
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The electrochemical reduction of N,N′-dithiobisphthalimide and N,N′-thiobisphthalimide is investigated using electrochemical techniques and theoretical calculations. The results are rationalized using adequate electron transfer theories. The reduction leads to the ejection of diatomic sulfur and involves an interesting autocatalytic mechanism. This mechanism is dependent on the concentration of the initial compound and the cyclic voltammetric scan rate. The starting material is reduced both at the electrode and through homogeneous electron transfer from the produced sulfur. The initial electron transfer follows a stepwise mechanism involving the formation of the corresponding radical anion. This is supported by both the electrochemical data and the theoretical calculation results. The radical anion of the N,N′-dithiobisphthalimide dissociates through cleavage of the N-S chemical bond and not the S-S chemical bond. Application of the extension of the dissociative electron transfer theory to the dissociation of radical anions shows that the N-S chemical bond dissociates despite being stronger than the S-S chemical bond. This is due to the large difference in the oxidation potentials of the two potential anions (the phthalimidyl anion and the phthalimidyl thiyl anion). The electrochemical reduction of N,N′-thiobisphthalimide involves the intermediate formation of N,N′-dithiobisphthalimide and hence the autocatalytic process is less efficient.
- Hamed, Emad M.,Koczkur, Kallum M.,Houmam, Abdelaziz
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p. 22600 - 22610
(2015/02/02)
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- Ammonolysis of anilides promoted by ethylene glycol and phosphoric acid
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Ethylene glycol (EG) and phosphoric acid have been found to promote the ammonolysis of a variety of diverse anilides as well as N-aryl carbamate, phthalimide, and urea substrates in the absence of transition metals or other Lewis acid promoters.
- Stephenson, Nickeisha A.,Gellman, Samuel H.,Stahl, Shannon S.
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p. 46840 - 46843
(2014/12/10)
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- Green oxidative synthesis of primary amides from primary alcohols or aldehydes catalyzed by a cryptomelane-type manganese oxide-based octahedral molecular sieve, OMS-2
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In this study, a new green synthetic route to primary amides, that is, aerobic oxidative amidation of primary alcohols or aldehydes with ammonia, has been developed. In the presence of a cryptomelane-type manganese oxide-based octahedral molecular sieve (OMS-2), various kinds of structurally diverse primary alcohols or aldehydes including aromatic, olefinic, heteroaromatic, and aliphatic ones can be converted into the corresponding primary amides in moderate to high yields (20 examples from primary alcohols and 11 examples from aldehydes). Furthermore, gram-scale amidation is also effective, and the analytically pure primary amides can easily be isolated. The present catalysis by OMS-2 is truly heterogeneous in nature, and the retrieved OMS-2 catalyst can be reused several times (at least 12 times for the amidation of 2-pyridinemethanol). Though the formation rates of the corresponding primary amide are gradually decreased by repeating reuse experiments, OMS-2 can be regenerated by calcination. The present OMS-2-catalyzed amidation of primary alcohols is composed of four relay steps: (i) oxidative dehydrogenation of primary alcohols, (ii) dehydrative condensation of aldehydes with ammonia, (iii) oxidative dehydrogenation of aldimines, and (iv) hydration of nitriles to form the corresponding primary amides. All steps (i)-(iv) can be promoted by the presence of OMS-2. The Royal Society of Chemistry 2013.
- Yamaguchi, Kazuya,Kobayashi, Hiroaki,Wang, Ye,Oishi, Takamichi,Ogasawara, Yoshiyuki,Mizuno, Noritaka
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p. 318 - 327
(2013/03/14)
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- Mechanistic aspects of oxidation of dextrose by N-bromophthalimide in acidic medium: A micellar kinetic study
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Kinetic investigations of oxidation of dextrose by N-bromophthalimide (NBP) in acidic medium in the presence of mercuric(II) acetate as a scavenger have been studied. In both the absence and presence of surfactants, the oxidation kinetics of dextrose by NBP shows a first-order dependence on NBP, fractional order on dextrose, and negative fractional order dependence on sulfuric acid. The determined stoichiometric ratio was 1:1 (dextrose:NBP). The variation of Hg(OAC)2 and phthalimide (reaction product) have an insignificant effect on reaction rate. Effects of surfactants, added acrylonitrile, added salts, and solvent composition variation have been studied. Activation parameters for the reaction have been evaluated from Arrhenius plot by studying the reaction at different temperature. The rate law has been derived on the basis of obtained data. A plausible mechanism has been proposed from the results of kinetic studies, reaction stoichiometry and product analysis. The role of anionic and non-ionic micelle was best explained by the Berezin's model.
- Singh, Minu
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p. 469 - 484
(2013/07/27)
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- Oxidative C-O cross-coupling of 1,3-dicarbonyl compounds and their heteroanalogues with N-substituted hydroxamic acids and N-hydroxyimides
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The oxidative C-O cross-coupling of 1,3-dicarbonyl compounds and their heteroanalogues, 2-substituted malononitriles and cyanoacetic esters, with N-substituted hydroxamic acids and N-hydroxy- imides was realized. The best results were obtained with the use of manganese (III) acetate [Mn (OAc) 3] or the cobalt(II) acetate catalyst [Co (OAc)2cat.]/ potassium permanganate [KMnO4] system as the oxidant. The synthesis can be scaled up to gram quantities of coupling products; yields are 30-94%. The reaction proceeds via a radical mechanism through the formation of nitroxyl radicals from N-substituted hydroxamic acids and N-hydroxyimides.
- Terent'Ev, Alexander O.,Krylov, Igor B.,Timofeev, Vladimir P.,Starikova, Zoya A.,Merkulova, Valentina M.,Ilovaisky, Alexey I.,Nikishin, Gennady I.
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p. 2375 - 2390
(2013/10/01)
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- Reactivity of ortho-palladated benzamides toward CO, isocyanides, and alkynes. synthesis of functionalized isoindolin-1-ones and 4,5-disubstituted benzo[ c ]azepine-1,3-diones
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Aryl palladium complexes [Pd{C6H4C(O)NRR′-2} I(tmeda)] [NRR′ = NH2 (1a), NHMe (1b), NMe2 (1c); tmeda = N,N,N′,N′-tetramethylethylenediamine] are prepared by oxidative addition of the corresponding 2-iodophenylbenzamides to "Pd(dba)2" ([Pd2(dba)3]·dba; dba = dibenzylideneacetone) in the presence of tmeda. Cationic cyclometalated derivatives [Pd{κ2C,O-C6H4C(O)NRR′- 2}(tmeda)]TfO (2a-c) are obtained by iodide abstraction from the appropriate complex 1 with AgTfO, while the deprotonation of the amide function of 1a or 1b with KOtBu gives the neutral amidate complexes [Pd{κ 2C,N-C6H4C(O)NR-2}(tmeda)] [R = H (3a), Me (3b)]. Complexes 2a,b and 3a,b react with CO under mild conditions to yield phthalimide (4a) or N-methylphthalimide (4b), whereas the reactions of derivatives 1c and 2c with CO are very slow and give N1,N 1,N2,N2-tetramethylphthalamide and phthalic anhydride. The reaction of 1b with 1 equiv of XyNC (Xy = 2,6-dimethylphenyl) or tBuNC affords Pd(0), (tmedaH)I, and 3-(2,6-dimethylphenylimino)-2- methylisoindolin-1-one (5b) or 3-(tert-butylimino)-2-methylisoindolin-1-one (5b′), respectively, while complex 1c reacts with 3 equiv of XyNC to give trans-[Pd{C(i=NXy)C6H4C(O)NMe2-2}I(CNXy) 2] (6). The seven-membered palladacycles [Pd{κ2C,O- C(X)i=C(X′)C6H4C(O)NRR′-2}(tmeda)]TfO [NRR′ = NH2 and X = Ph, X′ = Me (7a); NRR′ = NHMe and X = Ph, X′ = Me (7b), X = X′ = Ph (8b), Et (9b), CO 2Me (10b), X = CO2Me, X′ = Ph (11b), X = CO 2Et, X′ = Ph (12b); NRR′ = NMe2 and X = X′ = Ph (8c), Et (9c)] are obtained from the reactions of 2a-c with alkynes. Treatment of complexes 7a, 7b, 8b, and 9b with CO at room temperature gives the corresponding 2H-benzo[c]azepine-1,3-diones (14), resulting from the insertion of a molecule of CO into the Pd-C bond followed by a C-N reductive coupling. In contrast, the reactions of 11b or 12b with CO in the presence of residual water or 2 equiv of ROH (R = Me, Et) lead to 2-methyl-3- phenylisoindolin-1-one derivatives (15), resulting from a CO insertion followed by an intramolecular aza-Michael addition of the NHMe moiety to the activated vinyl group and subsequent hydrolysis or alcoholysis of the acyl-Pd bond. The neutral complex [Pd(κ2C,O-C14H13O 5)(tmeda)] (18) was synthesized by reacting the cationic derivative 10b with NaOMe in MeOH. Depalladation of 18 gives (E)-4- [methoxy(methoxycarbonyl)methylene]-2-methylisoquinoline-1,3(2H,4H)-dione (19).
- Frutos-Pedreno, Roberto,Gonzalez-Herrero, Pablo,Vicente, Jose,Jones, Peter G.
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p. 4664 - 4676
(2013/09/23)
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- Kinetics and mechanism of the oxidation of 4-Oxo-4-arylbutanoic acids by N-bromophthalimide in aqueous acetic acid medium
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The kinetics of oxidation of a series of substituted 4-oxobutanoic acids (Y-C6H4COCH2CH2COOH: Y = H, OCH 3, CH3, C6H5, Cl, Br or NO 2) by N-bromophthalimide have been studied in aqueous acetic acid medium at 30 C. The total reaction is second-order, first-order each in oxidant and substrate. The oxidation rate increases linearly with [H+], establishing the hypobromous acidium ion, H2O+Br, as the reactive species. A variation in ionic strength has no effect on the reaction rate. The order of reactivity among the studied 4-oxoacids is: 4-methoxy > 4-methyl > 4-phenyl > 4-H > 4-Cl > 4-Br > 3-NO2. The effect of changes on the electronic nature of the substrate reveals that there is a development of positive charge in the transition state. The activation parameters have been computed from Arrhenius and Eyring plots. Based on the kinetic results, a suitable mechanism has been proposed.
- Mohamed Farook,Alhaji,Uduman Mohideen,Seyed Dameen,Mitu, Liviu,Abshana Begam
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p. 1183 - 1193
(2013/07/26)
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- Intramolecular thermal transformations of N-phthalimidoaziridines: 1,3-dipolar cycloaddition and rearrangements
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The intramolecular thermal cycloaddition of N-phthalimidoaziridines at multiple bonds of substituents with the intermediate formation of azomethine ylides leads to condensed pyrrole derivatives, in which the five-membered ring is adjacent to a five-, six-, or seven-membered ring. Rearrangements, which sometimes become the predominant reactions, compete with cycloaddition. Thus, aziridines with aryl substituents readily isomerize to give imines with a 1,2-shift of the phthalimide group to one of the carbon atoms. Aziridines with one electron-withdrawing substituent probably do not open to give 1,3-dipoles but rather undergo a Cope-type rearrangement involving the three-membered ring and C=O bond of the second substituent. Even in intramolecular reactions, very low activity is found for the cyano group triple bond and aromatic ring bonds as dipolarophiles.
- Kuznetsov,Pan'Kova,Voronin,Vlasenko
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p. 1353 - 1366
(2014/07/21)
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- Hofmann-type rearrangement of imides by in situ generation of imide-hypervalent iodines(III) from iodoarenes
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The Hofmann-type rearrangement of aromatic and aliphatic imides using a hypervalent iodine(III) reagent generated in situ from PhI, m-CPBA, and TsOH·H2O proceeded in the presence of a base in alcohol to provide anthranilic acid derivatives and amino acid derivatives in high yields, respectively. This reaction proceeds through a tandem reaction via alcoholysis followed by a Hofmann rearrangement promoted by the formation of an imide-λ3-iodane intermediate.
- Moriyama, Katsuhiko,Ishida, Kazuma,Togo, Hideo
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scheme or table
p. 946 - 949
(2012/05/05)
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- Photoinduced electron-transfer chemistry of the bielectrophoric N-phthaloyl derivatives of the amino acids tyrosine: Histidine and tryptophan
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The photochemistry of phthalimide derivatives of the electron-rich amino acids tyrosine, histidine and tryptophan 8-10 was studied with respect to photoinduced electron-transfer (PET)induced decarboxylation and Norrish II bond cleavage. Whereas exclusive photodecarboxylation of the tyrosine substrate 8 was observed, the histidine compound 9 resulted in a mixture of histamine and preferential Norrish cleavage. The tryptophan derivative 10 is photochemically inert and shows preferential decarboxylation only when induced by intermolecular PET.
- Griesbeck, Axel G.,Neudoerfl, Joerg,Kiff, Alan De
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experimental part
p. 518 - 524
(2011/06/28)
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- Synthesis of the phosphonoanalogue of benzo[c]pyroglutamic acid
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Phosphonic analogue 1 of benzo[c]pyroglutamic acid was synthesized by three-step synthesis starting from N-tert-butylphtalimide and triethylphosphite. The acid-catalyzed, oxidative cascade conversion of phosphonate 11 to phthalimide and phosphoric acid diethyl ester was observed. A mechanism for this transformation was proposed. Taylor & Francis Group, LLC.
- Kachkovskyi, Georgiy O.,Kolodiazhnyi, Oleg I.
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experimental part
p. 2441 - 2448
(2011/02/25)
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- Gas-phase pyrolysis of N-alkoxyphthalimides to functionally substituted aldehydes: Kinetic and mechanistic study
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Flash vacuum Pyrolysis (FVP) of primary N-alkoxyphthalimides at 400-500 C° and 0.02 Torr gave functionally substituted aldehydes. A mechanism of this pyrolytic transformation was proposed based on the kinetic data and product analysis. ARKAT USA, Inc.
- Al-Etaibi, Alya M.,Al-Awadi, Nouria A.,Ibrahim, Maher R.,Ibrahim, Yehia A.
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experimental part
p. 149 - 162
(2010/12/25)
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- The first experimental demonstration of side chain extension of geoporphyrins in sediments
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To investigate the formation process of high carbon number (>C 32) sedimentary porphyrins, heating experiments of several porphyrins were performed. Chromic acid oxidation of the heating products of protoporphyrin IX dimethyl ester afforded 2-methyl-3-npropylmaleimide as the predominant product among the side-chain extension products formed. On the other hand, saturated substituents of etioporphyrin were also extended on heating to slowly form normal and branched homologs. These results may suggest that the transalkylation of porphyrin side chains proceeds mainly by a regioselective mechanism involving alkyl radical addition to a vinyl group of chlorophylls or their diagenetic products.
- Asahina, Kenta,Asano, Junya,Kumagai, Gen,Satou, Mitsuru,Nomoto, Kouichi,Kashiyama, Yuichiro,Mita, Hajime,Nomoto, Shinya
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body text
p. 1267 - 1269
(2011/02/16)
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- A cyclic porphyrin trimer as a receptor for fullerenes
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(Equation Presented). A cyclic porphyrin trimer has been synthesized which has a high affinity for fullerenes. It forms 1:1 complexes with C60 and C70 with association constants of 2×106 and 2×108 M-1, respectively, in toluene. Its affinities for C86 and La@C82 are too strong to measure by fluorescence titration. The solvent dependence of the association constants shows that solvation of both the guest and the host influence the binding strength.
- Gil-Ramirez, Guzman,Karlen, Steven D.,Shundo, Atsuomi,Porfyrakis, Kyriakos,Ito, Yasuhiro,Briggs, G. Andrew D.,Morton, John J. L.,Anderson, Harry L.
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supporting information; experimental part
p. 3544 - 3547
(2010/10/02)
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- Tri- and tetrasubstituted N-phthalimidoaziridines in 1,3-dipolar cycloaddition reactions
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The thermal reactions of the 2,2,3-trisubstituted N-phthalimidoaziridine 1a with dimethyl acetylenedicarboxylate (DMAD), thioketones 4a - 4d, and dimethyl azodicarboxylate (5) proceed even at room temperature leading to the five-membered cycloadducts 2a, 6 - 8, and 12, respectively, with retention of the spatial arrangement of the aziridine substituents, in contrast to the expectation based on the conservation of orbital symmetry in concerted reactions. The analogous reactions of the tetrasubstituted phthalimidoaziridine 1b with thioketones at 40° lead to the 1,3-thiazolidine derivatives 10 and 11 as mixtures of diastereoisomers. These unexpected results may be explained by either the isomerization of the intermediate azomethine ylides or a non-concerted stepwise cycloaddition reaction of these ylides with the dipolarophiles. The structures of some adducts have been determined by X-ray crystallography.
- Ushkov, Alexander V.,Kuznetsov, Mikhail A.,Linden, Anthony,Heimgartner, Heinz
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experimental part
p. 847 - 862
(2010/08/06)
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- A kinetic study of acid-catalyzed hydrolysis of some arylsulfonyl phthalimides
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The acid-catalyzed hydrolysis of arylsulfonyl phthalimides was studied in aqueous solutions of sulfuric, perchloric, and hydrochloric acid at 35.0 ± 0.1C. Analysis of the data by the excess acidity method and activation parameters, as well as substituent and solvent isotope effects, indicate hydrolysis by an A-2 mechanism at low acidity. At higher acidities, a changeover to an A-1 mechanism is observed.
- Kutuk, Halil,Ozturk, Seyhan
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scheme or table
p. 332 - 340
(2009/09/25)
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- PROCESS FOR THE PREPARATION OF ALKYL 5- (DICARBOXIMIDO) LEVULINATE AND ALKYL 4-OXO-PENTENOATE
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A method of manufacturing esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate. This method includes two reaction steps, wherein the first step of said two reaction steps is a bromination of alkyl-levulinate, to obtain alkyl-(3 and 5)-bromolevulinate, and the second step of said two reaction steps is a synthesis of esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate, by reacting the alkyl-(3 and 5)-bromolevulinate obtained in said first step with dicarboxyimide anion.
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Page/Page column 6-7
(2008/06/13)
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- Method for separation of reaction products from catalysts
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A method separates a reaction product from an imide compound catalyst represented by Formula (1) or an altered derivative thereof in a reaction mixture obtained as a result of a reaction in the presence of the imide compound catalyst by performing an extraction process using two organic solvents separable from each other to thereby separate the reaction product into one organic solvent layer and the imide compound catalyst or an altered derivative thereof into the other organic solvent layer, respectively: wherein R1 and R2 are each, for example, a hydrogen atom or an alkyl group, where R1 and R2 may be combined to form a double bond, an aromatic ring, or a non-aromatic ring; and X is an oxygen atom or a hydroxyl group. The method of the invention can efficiently and simply separate a reaction product from a catalyst and/or an altered derivative of the catalyst in a reaction mixture obtained as a result of a reaction of a substrate such as a hydrocarbon using N-hydroxyphthalimide or another imide compound as the catalyst.
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- PROCESS FOR PRODUCTION OF DICARBOXYLIC ACIDS
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A process of the present invention produces a corresponding dicarboxylic acid by oxidative cleavage of a cycloalkane with oxygen and performs a reaction in the presence of a catalyst including an imide compound and a metallic compound, the imide compound having a cyclic imide skeleton represented by following Formula (I): wherein X is an oxygen atom or an-OR group, and wherein R is a hydrogen atom or a hydroxyl-protecting group, under conditions of a reaction temperature of 80°C or higher and a concentration of the cycloalkane in a system of 21% by weight or more. The imide compound includes, for example, N-hydroxyphthalimide. The amount of the imide compound is, for example, from about 0.000001 to about 0.01 mole per mole of the cycloalkane. In the production of a corresponding dicarboxylic acid by catalytic oxidation of a cycloalkane with oxygen, the present invention can yield the dicarboxylic acid in a high space time yield even using a small amount of the catalyst.
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Page/Page column 19
(2008/06/13)
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- Photolysis experiments on phosmet, an organophosphorus insecticide
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The organophosphorus insecticide phosmet is used in plant protection as well as against parasites on animals. Phosmet showed numerous photoinduced reaction pathways, which first were studied in the presence of model environments for animal fur lipids (e.g
- Sinderhauf, Katrin,Schwack, Wolfgang
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p. 5990 - 5995
(2007/10/03)
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- Alkyl, alkenyl and alkynyl Chrysamine G derivatives for the antemortem diagnosis of Alzheimer's disease and in vivo imaging and prevention of amyloid deposition
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Amyloid binding compounds which are non-azo derivatives of Chrysamine G, pharmaceutical compositions containing, and methods using such compounds to identify Alzheimer's brain in vivo and to diagnose other pathological conditions characterized by amyloidosis, such as Down's Syndrome are described. Pharmaceutical compositions containing non-azo derivatives of Chrysamine G and methods using such compositions to prevent cell degeneration and amyloid-induced toxicity in amyloidosis associated conditions are also described. Methods using non-azo Chrysamine G derivatives to stain or detect amyloid deposits in biopsy or post-mortem tissue are also described. Methods using non-azo Chrysamine G derivatives to quantify amyloid deposits in homogenates of biopsy and post-mortem tissue are also described.
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- Kinetics and mechanisms of the acid-catalyzed hydrolyses of N-(4-substituted-arylsulfinyl)phthalimides
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The acid-catalyzed hydrolyses of N-(4-substituted-arylsulfinyl)phthalimides were studied in aqueous solutions of perchloric and sulfuric acids at 50.0 ± 0.1 and of hydrochloric acid at 40.0 ± 0.1°C. Analysis of the data by the Cox-Yates excess acidity method and substituent, temperature and solvent isotope effects indicate hydrolysis by an A2 mechanism at low acidity. At higher acidities a changeover to an A1 mechanism is observed. Copyright
- Kutuk, Halil,Bekdemir, Yunus,Soydas, Yasemin
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p. 224 - 228
(2007/10/03)
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- Oxidative Ammonolysis of o-Xylene to Phthalimide
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Catalytic characteristics of the oxide system V2O5-ZrO2 in oxidative ammonolysis of o-xylene to phthalimide were studied with the aim to choose an efficient catalyst. The surface acidity of a series of vanadium-zirconium catalysts was determined. A correlation between the chemical composition and acidic characteristics of the surface of the oxide system V2O5-ZrO2 was found.
- Sembaev, D. Kh.,Ivabovskaya, F. A.,Chukhno, N. I.
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- Exploratory studies probing the intermediacy of azomethine ylides in the photochemistry of N-phthaloyl derivatives of α-amino acids and β-amino alcohols
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Exploratory photochemical studies with N-phthaloyl derivatives of glutamic acid, aspartic acid, serine, threonine and analogous carboxylic acids and alcohols have been conducted to determine the generality of azomethine ylide forming decarboxylation and retro-aldol fragmentation reactions. Preferences in the competition between these excited state reaction pathways have been determined by studies with phthalimides which contain both α-amino acid and β-aminoethanol groups.
- Yoon, Ung Chan,Lee, Chan Woo,Oh, Sun Wha,Mariano, Patrick S.
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p. 11997 - 12008
(2007/10/03)
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- Investigation on the photoreactions of nitrate and nitrite ions with selected azaarenes in water
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The photoreactions of selected azaarenes with nitrate and nitrite ions were investigated under irradiation at λ = 313 nm. The excitation of both anions leads to several photochemical reactions forming mainly hydroxyl radicals and nitrogen oxides. The purification capability of natural waters i.e. the oxidation of inorganic and organic substances results from the formation of hydroxyl radicals. Nitrated isomers of azaarenes were found among the main products of the investigated photoreactions. The nitrogen oxides were responsible for the production of nitrated derivatives which possess a high toxic potential. Their formation was explained by the parallel occurance of two mechanism, a molecular and a radical one. The molecular mechanism became more important with increasing ionisation potentials of the azaarenes. The spectrum of oxidized products corresponded to the one got in the photoreactions of azaarenes with hydrogen peroxide. The formation of several oxidation and nitration products of the pyridine ring with its low electron density was explained by the reaction of excited states of azaarenes. The photoreactions with nitrite ions only led to the formation of oxidized and nitrated products. Nitroso products were not formed. The reactivity of nitrogen monoxide is too low for its reaction with the azaarenes.
- Beitz, Toralf,Bechmann, Wolfgang,Mitzner, Rolf
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p. 351 - 361
(2007/10/03)
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- SUBSTITUTED PROPIONYL DERIVATIVES
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The present invention relates to a compound represented by the following formula (1): [wherein, X1represents a carboxyl group which may be esterified or the like group; Y1represents a single bond, -O- or -N(R1)-; at least one of A1, A2and A3is a group represented by the following formula (2): -R2-a1-R3-a2→{wherein, R2represents a divalent C2-12hydrocarbon group, R3represents a single bond or a divalent C1-12hydrocarbon group, a1and a2individually represent a single bond, -S-, -SO-, -SO2-, -SO2NH-, -O-, -N(R4)-, -CON(R5)-, -C(=O)- or - Si(R6)(R7)- and → means bonding with Q1, Q2or Q3}, the remaining one or two of A1, A2and A3are the same or different and each independently represents a group represented by the following formula (3): -R8-a3-R9-a4→{wherein, R8and R9individually represent a single bond or a divalent C1-12hydrocarbon group, a3and a4individually represent a single bond, -S-, -SO-, -SO2-, -SO2NH-, -O-, - N(R10)-, -CON(R11)-, -C(=O)- or -SI(R12)(R13)- and → means bonding with Q1, Q2or Q3},; at least one of Q1, Q2and Q3represents a cyclic hydrocarbon group or heterocyclic group and the remaining one or two of Q1, Q2and Q3individually represent a hydrogen atom, a carboxyl group which may be esterified, a hydrocarbon group or a heterocyclic group] or salt thereof; and a pharmaceutical comprising the same as an effective ingredient. The compound exhibits strong squalene synthetase inhibitory action and is therefore useful as a pharmaceutical for the treatment·prevention of hypercholesterolemia, hyperlipemia or arteriosclerosis.
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- Investigations of reactions of selected azaarenes with radicals in water. 1. Hydroxyl and sulfate radicals
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The oxidative degradation of binuclear azaarenes is studied in a number of environmentally relevant radical reactions. The comparison between oxidation mechanisms of hydroxyl and sulfate radicals, as well as between dark and photoreactions, is done. Most of the products formed are identified. With the change from dark to photoreactions of quinoline and isoquinoline, a shift of the oxidation center from the benzene to the pyridine rings is observed. The reaction behavior of the benzodiazines can be derived from the reaction patterns of quinoline and isoquinoline. The rate constants of second order are determined for the reactions of the azaarenes with carbonate radicals. The rate constants and the differences in the products formed conformably prove the importance of the inclusion of excited states in the reaction mechanism. The application of the frontier orbital concept allows an easy interpretation. Electron transfer reactions resulting in radical oxygen species are shown to be product determining in direct photolysis, too.
- Beitz, Toralf,Bechmann, Wolfgang,Mitzner, Rolf
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p. 6760 - 6765
(2007/10/03)
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- Investigations of reactions of selected azaarenes with radicals in water. 2. Chlorine and bromine radicals
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The halogen radicals that react with azaarenes are produced by the photooxidation of halogenide anions with hydroxyl and sulfate radicals and exist as complexes of the radical and the respective halogenide anion in the aqueous phase. The main reaction products of the reactions are identified, and in the case of the bromine radicals, the second order rate constants are determined. Oxidation takes place according to the different redox potentials of the two reactants and is especially observed for chlorine radicals. A typical product spectrum comparable with that in reactions with hydroxyl and sulfate radicals has been found. The formation of some oxidation products in reactions of bromine radicals is in contradistinction to the oxidation potentials of the azaarenes and can be understood only by the reaction of their excited states. The halogenation is the main reaction of the azaarenes. Halogenation products of both, the benzene and the pyridine/diazine rings, have been found. The halogenation of the pyridine/diazine ring again requires the reaction of excited states. The majority of derivatives is halogenated in substitution reactions, but in the reaction of benzo[h]quinoline, addition is also observed. The resonance energy per electron is responsible for the change in the halogenation mechanism from substitution to addition.
- Beitz, Toralf,Bechmann, Wolfgang,Mitzner, Rolf
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p. 6766 - 6771
(2007/10/03)
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- Reductive desulfurization of organosulfur compounds with sodium in liquid ammonia
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Greater than 95% sulfur removal was observed when dialkyl mono or polysulfides were treated with Na in liquid ammonia. Polycyclic aromatic sulfur heterocycles were only moderately desulfurized under these conditions while phenylthio derivatives gave thiophenol as the major product and dithiophenols as the minor products.
- Yu, Zhengkun,Verkade, John G.
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- Photochemical transformations of proteinogenic and non-proteinogenic amino acids
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The photochemistry of N-activated enantiomerically pure α-amino acids is described with emphasis on chemo-, regio-, stereo-, and spin selectivity. An especially valuable chromophore is the phthalimido group. The first excited singlet states are short-lived and deactivated (chemically) via homolytic CH cleavage or (physically) via electron-transfer steps. The first excited triplet states are chemically deactivated via electron-transfer reactions and subsequent deprotonation/coupling steps. A wide variety of product types were synthesized, and potential target molecules were available by tuning the reaction conditions. Also remote groups can be activated by means of electron-transfer steps, which represents an attractive new synthetic protocol for macrocyclization.
- Griesbeck, Axel G.
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p. 272 - 283
(2007/10/03)
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- Cyclic amide derivatives as potential prodrugs. Synthesis and evaluation of N-hydroxymethylphthalimide esters of some non-steroidal anti-inflammatory carboxylic acid drugs
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N-Hydroxymethylphthalimide (HMPhI) esters 5a-d of some nonsteroidal anti-inflammatory drugs were synthesized and evaluated as potential prodrugs with the aim of depressing the gastrotoxicity of the parent drugs by temporarily masking the carboxylic acid function. The ester prodrugs were synthesized through condensation of N-hydroxymethylphthalimide and the mixed carboxylic-carbonic anhydride intermediate or the corresponding acid chloride of the parent acid. Their structures were confirmed by 1H-NMR spectra and the purity has been assessed by TLC and elemental analyses. An HPLC method has been developed for investigation of the hydrolysis kinetics in aqueous buffer solutions and in 80% rabbit plasma. The lipophilicity parameters log P and log k' were determined and showed that the prodrugs were found to be more lipophilic (log P > 2) than the parent drugs. A considerable chemical stability of all compounds (t( 1/4 ) = 4.7-21.9 h) has been observed in non-enzymatic simulated gastric fluid (hydrochloric acid buffer of pH 1.3), while at pH 7.4 only prodrugs 5b-d are sufficiently stable (t( 1/4 ) ~3-5 h). Meanwhile, rapid conversion to the parent drugs 3a-d was observed in 80% rabbit plasma (t( 1/4 ) ~1.0-11.5 min). Potential ulcerogenicity on rat stomach mucosa of the prodrugs and the parent drugs after oral administration for 4 days was studied using a scanning electron microscope. Gross observations and scanning electro-micrographs showed that the prodrugs are significantly less irritating to gastric mucosa than the parent NSAIDs. This result suggests that N-hydroxymethylphthalimide esters may be useful as nonulcerogenic prodrug forms for acidic NSAIDs.
- Omar, Farghaly A.
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p. 123 - 131
(2007/10/03)
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- Reaction of n-aminophthalimide derivatives with aluminum chloride in benzene
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The reaction of N-aminophthalimide derivatives with AlCl3 in benzene has been investigated. From N-amino- and N-benzamidophthalimide (1a and 1b), N-amino- and N-benzamido3,3-diaryl-2,3-dihydroisoindol-1-ones (2) are obtained in high yield by initial attack of benzene on the imide carbonyl, assisted by the neighboring nitrogen atom. From N-arylaminophthalimide derivatives (4), the N-N bond is cleaved heterolytically to give an arylnitrenium ion and canonical forms involving the arene which are trapped by benzene to give aminobiaryls and N-arylanilines.
- Ohwada, Atsushi,Li, Hao,Sakamoto, Takeshi,Kikugawa, Yasuo
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p. 225 - 233
(2007/10/03)
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- Regioselective biotransformations of dinitriles using Rhodococcus sp. AJ270
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A variety of dinitriles have been hydrolysed selectively under very mild conditions using Rhodococcus sp. AJ270. Aliphatic dinitriles NC[CH2]nCN 1 undergo regioselective hydrolysis to give the mono acids 2 with up to 4 methylenes between the nitrile functions while those with n > 4 give the diacids 3 in good yield. Dinitriles NC[CH2]nX[CH2]nCN 4 bearing an ether or sulfide linkage are efficiently transformed into the mono acids 5 when an oxygen is placed β, γ or δ to the cyano group or a β- or γ-sulfur is present. Hydrolysis of N,N-bis(2-cyanoethyl)anilines 4h-j takes place slowly affording exclusively the monoacids 5h-j while the monocyano amides 5o-p are obtained as the sole isolable product from rapid hydrolysis of the corresponding N,N-bis(2-cyanomethyl)butylamine 4o and N,N-bis(3-cyanopropyl)butylamine 4p. Higher homologues of arylimino- and butylimino-dinitriles are inert to enzymatic hydrolysis. A variety of other aliphatic dinitriles have been converted readily into mono acids in good to excellent yields except for o-phenylenediacetonitrile which gives o-phenylenediacetamide as the major product. The title organism also effects the hydrolysis of aromatic dinitriles with regiocontrol such as m- and p-dicyanobenzenes, but nct the ortho-substituted analogue. The scope and limitations of this enzymatic process have been systematically studied and the mechanism of regioselective hydrolysis has been discussed in terms of a chelation-deactivation effect.
- Meth-Cohn, Otto,Wang, Mei-Xiang
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p. 3197 - 3204
(2007/10/03)
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- 'Dry' Hydrolysis of Nitriles Effected by Microwave Heating
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The preparation of carboxylic acids from their corresponding nitriles by a 'dry hydrolysis' with dicarboxylic acids, in the absence of solvent, has been investigated.The reaction proceeds very slowly at atmospheric pressure, but high yields can be obtained in much shorter reaction times under pressure.The mechanism of the reeaction has been studied and its rate constant and activation energy determined in the case of a model reaction (preparation of phenylacetic acid from benzyl cyanide with phthalic acid) under both microwave and conventional heating.No 'microwave kinetic effect' has been detected, but at high temperatures microwave heating gives better yields and selectivities.
- Chemat, Farid,Poux, Martine,Berlan, Jacques
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p. 2597 - 2602
(2007/10/02)
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- Photochemistry of N-phthaloyl derivatives of electron-donor-substituted amino acids
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The hydroxy substituted amino acids threonine and serine have been investigated concerning their photochemical behaviour when activated as N-phthaloyl substrates. The methyl esters 1a and 2a solely underwent cleavage of the central C-C single bond to give the glycine derivative 3 and an aldehyde fragment. C-unprotected threonine derivative 1b is converted into a series of products the composition of which depends on solvent polarity and on the electronic state. Three reaction modes were detected for the N-phthaloyl derivatives of the aryl substituted amino acids phenylalanine, tyrosine, and dihydroxyphenylalanine (DOPA): (A) decarboxylation (only for 12a), (B) β-fragmentation, and (C) ring enlargement reaction. Processes B and C are initiated by photo electron transfer (PET), as the solvent dependence revealed. The DOPA derivatives 14a and 14b are the most prominent examples due to their exclusive PET reactivity leading to type C products (18a,b) with high diastereoselectivity (90:10). PET results from the first excited singlet states of 12 and 13, whereas for compounds 14 the corresponding triplet states are involved. The correlation between photochemical reactivity and the fluorescence decay data for compounds 12a,b and 15 is discussed.
- Griesbeck,Henz,Hirt,Ptatschek,Engel,Loffler,Schneider
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p. 701 - 714
(2007/10/02)
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- Mechanism of Hydrolysis of O-Imidomethyl Derivatives of Phenols
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Three series of O-imidomethyl derivatives of para-substituted phenolic compounds were synthesized and their rates of hydrolysis were studied.Saccharin, phthalimide, and succinimide served as the imide portions of the derivatives.Their rates of hydrolysis were found to be first order with respect to hydroxide from pH 7.0 to 10 or 11 and dependent on the acidity (leaving group potential) of both the imide and the phenol portions.The more acidic the imide or the phenol, the faster the rate of hydrolysis.However, the rates of hydrolysis were more sensitive to the acidity of the phenol.Trapping experiments with cyanide also suggested that the phenol anion was functioning as the leaving group in what is apparently an SN2 reaction.An amide derivative was found to hydrolyze more slowly than predicted from the analogous series and the pKa of the amide.This result is apparently due partially stereoelectronic constraints in the imide series that cause the CH2-O bond to be oriented more nearly perpendicular to the plane of the C(=O)N group and hence more accessible to nucleophilic attack.
- Getz, John J.,Prankerd, Richard J.,Sloan, Kenneth B.
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p. 4913 - 4918
(2007/10/02)
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- Redox-Mediated Decarboxylative Photo-Phenylselenenylation of N-Acyloxyphthalimides
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Decarboxylative phenylselenenylation of N-acyloxyphthalimides by visible light irradiation in aqueous solvents using catalytic amount of Ru(bpy)3Cl2 as a sensitizer in the presence of one equivalent of BNAH and 0.5 equivalent of diphenyl diselenide effici
- Okada, Keiji,Okubo, Katsura,Morita, Naoto,Oda, Masaji
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p. 2021 - 2024
(2007/10/02)
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- Cephem compounds
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Cephalosporin antibiotics having a 3-position substituent of the formula: STR1 are described, wherein X is --CO--, --SO2 -- or --COCH2 --; Y is --CO--, --SO2 -- or --CH2 --; Q is a benzene, pyridine or naphthalene ring, R1 and R2 are ortho with respect to each other and are independently hydroxy or of the formula O--M wherein M is a moiety and the O--M bond is cleavable in vivo and ring Q may be further substituted by a variety of atoms and groups. Processes for their preparation and use are described.
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- Antiinflammatory leukotriene B4 analogs
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This invention encompasses novel analogs of Leukotriene B4 which are selected from a compound of formula I, B--C~C--CH2 C(M2)--C~C--Y--C(M1)--A, or formula II, B--C~C--CH2 C(M2)--C~C--P--R5 --A: wherein Y is: STR1 wherein P is: STR2 Patentable intermediates, process for making the novel analogs and intermediates and preparation of useful pharmacological agents comprising the analogs and intermediates are part of this invention.
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- Pyridazinones having cardiotonic and beta blocking activities
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Pyridazinones of the following formula (I): STR1 where R1 -R4 are a variety of substituents and L is a linking group, a pharmaceutical composition for treating congestive heart failure, novel intermediates, methods for such treatment and processes for preparing compounds of formula (I).
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- Reductive decarboxylation of N-(acyloxy)phthalimides via redox-initiated radical chain mechanism
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Highly efficient reductive decarboxylation of N-(acyloxy)phthalimides which are readily prepared from carboxylic acids was achieved by visible light irradiation using Ru(bpy)3Cl2 as a sensitizer in the presence of BNAH and t-BuSH via radical chain mechanism.
- Okada,Okubo,Morita,Oda
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p. 7377 - 7380
(2007/10/02)
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- Photochemical Chlorodecarboxylation via an Electron Transfer Mechanism
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A new method of chlorodecarboxylation of carboxylic acids via N-acyloxyphthalimides is developed; the reaction proceeds upon irradiation of N-acyloxyphthalimides in the presence of 1,4-diazabicyclooctane in ButOH-CCl4-H2O (53:42:5 v/v) in moderate to high yields.
- Okada, Keiji,Okamoto, Kazushige,Oda, Masaji
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p. 1636 - 1637
(2007/10/02)
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- HETEROGENEOUS CATALYTIC AMMOXIDATION OF o-XYLENE TO PHTHALIMIDE: ANALYSIS OF THE REACTION NETWORK
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The analysis of the reaction variables on the ammoxidation of o-xylene using different V-Ti-O catalysts evidences that phthalimide is selectively formed by the direct oxidation of intermediate o-tolunitrile.When an excess of ammonia is present, both o-tolunitrile and phthalimide are converted to phthalonitrile; however, the rates of these consecutive reactions may be controlled by a suitable distribution of vanadium oxide species on the TiO2 surface.
- Centi, Gabriele,Pinelli, Davide,Trifiro, Ferruccio
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p. 133 - 138
(2007/10/02)
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