- Rates of Formation of Iminium Ions from Acetone and Monoprotonated 2-pyrrolidine
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The kinetics of the reaction of 2-pyrrolidine (1) with acetone has been studied by experiments in which the reversibly formed iminium ion is captured irreversibly by hydroxylamine.From experiments over the pH range 8.5-10.6 rate constants for iminium ion formation from 1 and 1-H+ were obtained.These rate constants were smaller than the corresponding rate constant for pyrrolidine, but the value for 1-H+ was large enough to show that the intermediate carbinolamine was undergoing internal acid-catalyzed dehydration to give the iminium ion.
- Hine, Jack,Evangelista, Ramon A.
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- Metal-free artificial nucleases based on simple oxime and hydroxylamine scaffolds
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Hydrolysis of DNA is of increasing importance in biotechnology and medicine. In this Letter, we present the DNA-cleavage potential of metal-free hydroxylamines and oximes as new members of nucleic acid cleavage agents.
- Fernandes, Luciano,Fischer, Franciele L.,Ribeiro, Carolina W.,Silveira, Gustavo P.,Sa, Marcus M.,Nome, Faruk,Terenzi, Hernan
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- Selective synthesis of dimethyl ketone oxime through ammoximation over Ti-MOR catalyst
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Titanosilicate with the MOR topology (Ti-MOR), postsynthesized from highly dealuminated mordenite and TiCl4 vapor through a solid–gas reaction, was highly active and selective for the liquid-phase ammoximation of dimethyl ketone (DMK) with ammonia and hydrogen peroxide. The parameters effecting the formation of the ammoximation product of dimethyl ketone oxime were investigated systematically in a batch-type reactor, and the optimized conditions were further applied to continuous ammoximation of DMK in a slurry reactor. Ti-MOR was superior to other titanosilicates in terms of activity and lifetime. TS-1 was not suitable for the ammoximation of DMK, whereas Ti-MWW required a higher catalyst loading to reach a reasonable activity, and they both easily produced a main byproduct of oxidative coupling of dimethyl ketone oxime. The deactivation behavior of Ti-MOR was investigated. Ammonia-induced structural desilication and accompanied Ti sites migration altered a more serious influence on the catalyst duration than coke deposition during continuous ammoximation.
- Ding, Jianghong,Wu, Peng
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- Stereochemical and electronic interaction studies of α-heterosubstituted acetone oximes
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The free νC=N bands in the IR spectra of some α-heterosubstituted acetone oximes show the existence of only a monomeric form in chloroform solutions below 1E-2 M, while in carbon tetrachloride self-associated species are also present.The 1H and 13C NMR chemical shift data indicate the predominance of the E over the Z isomer.The ΔνC=N frequency shifts and molecular mechanics strongly suggest that the oximes are in the gauche conformation.X-ray diffraction data have shown that the single dimethylaminoacetone oxime isomer exists in the E configuration and gauche conformation.Non-additivity effects for the α-methylene carbon chemi cal shifts seem to indicate the occurence of a ?C=N/?*C-x interaction besides the ?*C=N/?C-X hyperconjugative interaction.
- Olivato, P. R.,Ribeiro, D. S.,Rittner, R.,Hase, Y.,Pra del, D.,Bombieri, G.
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- Influences of fluorine implantation on catalytic performance and porosity of MOR-type titanosilicate
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Fluorine species were implanted into the framework of Ti-MOR by post-treatment with fluorides in order to modify the microenvironment around Ti active sites and then to improve their catalytic activity in liquid-phase oxidation. The effects of NH4F amount, fluorination temperature, and solvent on the catalytic performance of F-Ti-MOR were investigated in detail. Methanol was found to be superior to water in fluorination. Fluorine implantation increased the electropositivity of Ti active sites through forming SiO3/2F units in the neighborhood, which enhanced the catalytic performance in the ammoximation of cyclohexanone remarkably. F-Ti-MOR prepared under optimized fluorination conditions showed a cyclohexanone conversion of 99% in comparison to only 30% conversion given by primitive Ti-MOR. Meanwhile, the implanted fluorine species captured the organic molecules with a relatively large dimension tightly, creating enormous steric hindrances that prevented other molecules, in particular those with bulky molecular dimensions, from diffusing into channels freely. Thus, F-Ti-MOR showed much lower activity than Ti-MOR in the hydroxylation of aromatics.
- Yang, Yulin,Ding, Jianghong,Wang, Binshen,Wu, Jing,Zhao, Chen,Gao, Guohua,Wu, Peng
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- Kinetics and mechanism of the copper-catalysed oxygenation of 2-nitropropane
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Primary and secondary nitro compounds react with dioxygen in the presence of copper metal and N ligands such as N,N,N′,N′-tetramethylethylenediamine (tmeda), 2,2′-bipyridine (bpy), and 1,10-phenantroline (phen) in various solvents to form aldehydes or ketones. More coordinating solvents as well as donor N ligands accelerate the reaction remarkably. The oxygenolysis of 2-nitropropane (NPH) in the presence of copper and tmeda in DMF results in acetone and acetone oxime. The amount of tmeda influences the chemoselectivity, higher tmeda concentrations preferentially lead to the formation of the oxime. The kinetics of the reaction, measured at 90 °C, resulted in a rate equation of first-order dependence on copper and dioxygen and second-order dependence on 2-nitropropane. The rate constant, activation enthalpy, and entropy at 363.16 K are as follows: kcat = (5.37 ± 0.34) × 10-2 Mol-3 dm9 s-1, Ea = 131 ± 4 kJ mol-1, ΔH? = 127 ± 4 kJ mol-1 and ΔS? = 80 ± 13 J mol-1 K-1. The catalytically active intermediates CuII(NP)2(tmeda) and CuII(NO2)2(tmeda) in the catalytic cycle were isolated and their structures determined by X-ray crystallography. The kinetics of the stoichiometric oxygenation of CuII(NP)2(tmeda) to CuII(NO2)2(tmeda) and acetone resulted in the overall second-order rate equation with a rate constant, activation enthalpy, and entropy at 313.16 K of ks = 0.46 ± 0.02 mol-1 dm3 s-1, Ea = 38 ± 1 kJ mol-1, ΔH? = 35 ± 1 kJ mol-1 and ΔS? = -142 ± 13 J mol-1 K-1, respectively. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Balogh-Hergovich, Eva,Greczi, Zoltan,Kaizer, Jozsef,Speier, Gabor,Reglier, Marius,Giorgi, Michel,Parkanyi, Laszlo
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- Cyclization of N-allylthiourea derivatives by the action of α-chloronitrosoalkanes
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A convenient method is proposed for obtaining difficultly available derivatives of 2-amino-5-chloromethyl-2-thiazoline by the cyclization of N-allylthioureas under the action of α-chloronitrosoalkanes. It is assumed that the reaction proceeds as a halogenophilic process leading to the intermediate formamidinesulfenyl chloride which is rapidly and selectively cyclized with the formation of 2-amino-2-thiazoline derivatives. 1998 Plenum Publishing Corporation.
- Tkachenko,Pushin,Sokolov,Fedoseev,Martynov
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- Six-at-Once Dedeuteration of Acetone-d6 in the Presence of 3-exo--2-exo-norbornanamine
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3-exo--2-exo-norbornanamine (2) was prepared and used as a catalyst in aqueous solution at 35 degC for the dedeuteration of acetone-d6.Monoprotonated 2 acts as an effective catalyst by transforming the ketone to an iminium ion and then using its dimethylamino group to dedeuterate the iminium ion by internal basic catalysis.At pH 9.95 the most common result of iminium-ion formation is the exchange of all six deuterium atoms.This requires a mechanism for cis-trans isomerization of the intermediate iminium ion.The gem-diamine mechanism proposed earlier for iminium ions derived from cyclopentanone helps explain why 2 gives six-at-once exchange while some rather similar diamines do not.The kinetics of iminium-ion formation from 2 and acetone were studied by the hydroxylamine-capture technique.The rates of iminium-ion formation thus obtained are reasonably consistent with those obtained in the deuterium exchange experiments.
- Hine, Jack,Tsay, Hwai-Min
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- Nickel-Catalyzed NO Group Transfer Coupled with NOxConversion
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Nitrogen oxide (NOx) conversion is an important process for balancing the global nitrogen cycle. Distinct from the biological NOx transformation, we have devised a synthetic approach to this issue by utilizing a bifunctional metal catalyst for producing value-added products from NOx. Here, we present a novel catalysis based on a Ni pincer system, effectively converting Ni-NOx to Ni-NO via deoxygenation with CO(g). This is followed by transfer of the in situ generated nitroso group to organic substrates, which favorably occurs at the flattened Ni(I)-NO site via its nucleophilic reaction. Successful catalytic production of oximes from benzyl halides using NaNO2 is presented with a turnover number of >200 under mild conditions. In a key step of the catalysis, a nickel(I)-?NO species effectively activates alkyl halides, which is carefully evaluated by both experimental and theoretical methods. Our nickel catalyst effectively fulfills a dual purpose, namely, deoxygenating NOx anions and catalyzing C-N coupling.
- Padmanaban, Sudakar,Choi, Jonghoon,Vazquez-Lima, Hugo,Ko, Donghwi,Yoo, Dagyum,Gwak, Jinseong,Cho, Kyung-Bin,Lee, Yunho
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supporting information
p. 4585 - 4593
(2022/03/02)
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- Rhodium(III)-Catalyzed Direct C-H Arylation of Various Acyclic Enamides with Arylsilanes
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The stereoselective β-C(sp2)-H arylation of various acyclic enamides with arylsilanes via Rh(III)-catalyzed cross-coupling reaction was illustrated. The methodology was characterized by extraordinary efficacy and stereoselectivity, a wide scope of substrates, good functional group tolerance, and the adoption of environmentally friendly arylsilanes. The utility of this present method was evidenced by the gram-scale synthesis and further elaboration of the product. In addition, Rh(III)-catalyzed C-H activation is considered to be the critical step in the reaction mechanism.
- Li, Xiaolan,Sun, Kai,Shen, Wenjuan,Zhang, Yong,Lu, Ming-Zhu,Luo, Xuzhong,Luo, Haiqing
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supporting information
p. 31 - 36
(2021/01/09)
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- Visible-Light-Mediated Strategies for the Preparation of Oxime Ethers Derived from O-H Insertions of Oximes into Aryldiazoacetates
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Two visible-light-mediated O-H insertion protocols involving oximes and aryldiazoacetates leading to different products depending on the solvent employed are reported. In DCM, direct O-H insertion takes place. In THF, there is the additional incorporation of the ring-opened form of this solvent into the structure of the product. These metal-free protocols are mild and tolerant to air and moisture. The preparation of an acaricide has been developed as an example of synthetic application.
- Duarte, Marcelo,Jurberg, Igor D.,Le?o, Luiz Paulo M. O.,Saito, Felipe A.,Stivanin, Mateus L.
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supporting information
p. 17528 - 17532
(2021/12/02)
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- Annulation of Oxime-Ether Tethered Donor–Acceptor Cyclopropanes
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Novel oxime-ether tethered cyclopropanes, when exposed to Yb(OTf)3 and heat, annulate to generate hydropyrrolo-oxazines products that can be taken to their respective pyrrolidines via hydrogenative N?O bond cleavage. The hydropyrrolo-oxazines are generated in a diastereoselective manner isolating the cis or trans product based on the temperature of the reaction. 20 examples of selective cis and trans hydropyrrolo-oxazines were generated in high yields by temperature control.
- Irwin, Lauren C.,Allen, Meredith A.,Vriesen, Matthew R.,Kerr, Michael A.
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p. 171 - 175
(2019/12/24)
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- Arylboronic Acid-Catalyzed C-Allylation of Unprotected Oximes: Total Synthesis of N-Me-Euphococcine
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O-Unprotected keto-and aldoximes are readily C-allylated with allyl diisopropyl boronate in the presence of arylboronic acid catalysts to yield highly substituted N-α-secondary and tertiary homoallylic hydroxylamines. The method was used in the total synthesis of the trace alkaloid N-Me-Euphococcine.
- Kürti, László,Kattamuri, Padmanabha V.,Siitonen, Juha H.,Yousufuddin, Muhammed
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supporting information
(2020/03/24)
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- Stereospecific synthesis of 1,5-disubstituted tetrazoles from ketoximes via a Beckmann rearrangement facilitated by diphenyl phosphorazidate
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A novel method for the stereospecific synthesis of 1,5-disubstituted tetrazoles from ketoximes via the Beckmann rearrangement was developed using diphenyl phosphorazidate (DPPA) as both the oxime activator and azide source. Various ketoximes were transformed into the corresponding 1,5-disubstituted tetrazoles with exclusive trans-group migration and no E-Z isomerization of the ketoxime. This method enables the preparation of 1,5-disubstituted tetrazoles without using toxic or explosive azidation reagents.
- Ishihara, Kotaro,Shioiri, Takayuki,Matsugi, Masato
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supporting information
p. 1295 - 1298
(2019/04/13)
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- Organic synthesis intermediate acetone oxime synthesis method
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The invention relates to an organic synthesis intermediate acetone oxime synthesis method, which mainly comprises: dissolving 0.5 mol hydroxylamine phosphate in 20 L of a potassium chloride solution,slowly adding 0.6-0.8 mol of an acetone solution, controlling the solution temperature at 35-39 DEG C, standing for 90-110 min after the adding, reducing the solution temperature to 31-34 DEG C, adding 0.9 mol of a potassium bicarbonate solution, adjusting the pH value of the solution to 8.5-9, controlling the solution temperature at 41-45 DEG C, layering after cooling, extracting the obtained oillayer, carrying out pressure reducing distillation, collecting the distillate at a temperature of 90-95 DEG C, washing with a cyclohexane solution, washing with an isopropanol solution, dehydrating with a dehydrating agent, and carrying out cooling crystallization to obtain the finished product acetone oxime.
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Paragraph 0006; 0010-0015
(2018/07/10)
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- High add valued application of turpentine in crop production through structural modification and qsar analysis
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Turpentine is a volatile component of resin, which is an abundant forest resource in Southern China. As one of the most important components, the integrated application of-pinene has been studied. The broad-spectrum evaluation of -pinene and its analogues has, therefore, been necessary. In an attempt to expand the scope of agro-activity trials, the preparation and the evaluation of the herbicidal activity of a series of -pinene analogues against three agricultural herbs were carried out. In accordance with the overall herbicidal activity, it is noteworthy that compounds 6k, 6l, and 6m demonstrated extreme activity with IC50 values of 0.065, 0.065, and 0.052 mol active ingredients/hectare against E. crus-galli. The preliminary structure-activity relationship (SAR) was analyzed and the compounds with the appropriate volatility and substituent type that had beneficial herbicidal activity were analyzed. Simultaneously, the quantitative structure-activity relationship (QSAR) model was built and the most important structural features were indicated, which was, to a certain extent, in line with the SAR study. The study aimed to study the application of the forest resource turpentine in agriculture as a potential and alternative approach for comprehensive utilization.
- Gao, Yanqing,Li, Jingjing,Li, Jian,Song, Zhanqian,Shang, Shibin,Rao, Xiaoping
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- Preparation method for acetoxime
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The invention relates to a preparation method for acetoxime. The preparation method comprises the following steps: a) preparation of a reaction system: adding ketoxime and acetone in a molar ratio of1.0: (5.0-35.0) into a reactor, then adding an acid catalyst and a solvent, and carrying out uniform mixing in the reactor under stirring to form the reaction system which has a pH value of 1 to 5; b)a synthetic reaction of acetoxime: heating the reaction system obtained in step a) and carrying out the reaction for 5 to 10 h with reaction temperature controlled to be 5 to 100 DEG C and a pressurecontrolled to be 0 to 2 atm; and c) purification of acetoxime: purifying a product obtained in step b) so as to obtain acetoxime. The method of the invention has the advantages of high reaction conversion rate, high acetoxime selectivity, simple reaction process, environmental friendliness, reduced environmental pollution and easy industrial production.
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Paragraph 0020-0081
(2018/06/04)
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- Novel process for synthesizing oxime through in-situ generated ammonia
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The invention discloses a novel process for synthesizing oxime through in-situ generated ammonia. The novel process is characterized in that ammonium salt and strong alkali and weak acid salt generate ammonia in situ, and then the ammonia reacts with ketone and hydrogen peroxide under catalysis of a titanium silicalite molecular sieve. The synthetic process has the advantages of simple oximation reaction, mild reaction conditions, few by-products, high product yield and environmentally friendliness. The synthesizing method is simple, an aftertreatment process is simple and convenient and has very strong operability and repeatability, and industrial production is promoted.
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Paragraph 0030; 0031; 0032; 0033
(2017/07/19)
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- The fullerene dieno 3, 4 - dihydro pyrrole derivative and its preparation method
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The invention relates to a fullereno-3,4-dihydropyrrole derivative and a preparation method thereof. The compound has the structure as shown in the specification, wherein R1 is -Ar or -CH3; R2 is -H or -CH3; and R3 is -H, -CH3 or -Ph. The novel [60] fullereno-3,4-dihydropyrrole compound indicates that [60]fullerene exhibits uniqueness in structure and has specialty in reactivity which is deficient in general substances. As an important intermediate of fine chemical products, the product dihydropyrrole has wide application in the fields such as medicines, pesticides, coatings, daily chemicals and polymer materials.
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Paragraph 0060
(2017/10/31)
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- A process for synthesizing of cyclohexanone oxime (by machine translation)
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The invention discloses a process for synthesizing of cyclohexanone oxime, in carbonate aqueous solution is in the system, in order to titanium-silicon molecular sieve as the catalyst, ketone, ammonia and hydrogen peroxide produced by the reaction of oxime; and, in the reaction process through the pH value of the reaction system to determine the real-time monitoring of the reaction process and to determine the optimal reaction mixture ratio. By monitoring the reaction system pH value to judge in the reaction process to determine the optimal reaction ratio, further through the carbonate aqueous solution to adjust the pH value of the system in order to improve the reaction speed and ammonia conversion rate. (by machine translation)
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Paragraph 0033; 0034
(2017/08/29)
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- A hydrophilic inorganic framework based on a sandwich polyoxometalate: Unusual chemoselectivity for aldehydes/ketones with in situ generated hydroxylamine
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A hydrophilic inorganic porous catalyst was prepared via the hydrothermal method. The combination of [WZn3(H2O)2(ZnW9O34)2]12- and Co(ii) provides a synergistical catalytic way to promote oximation of aldehyde/ketone with in situ generated hydroxylamine that initially produces an oxime, which further either dehydrates into a nitrile or undergoes a Beckmann rearrangement to form an amide.
- Xing, Songzhu,Han, Qiuxia,Shi, Zhuolin,Wang, Shugai,Yang, Peipei,Wu, Qiang,Li, Mingxue
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supporting information
p. 11537 - 11541
(2017/09/18)
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- Direct preparation of oximes and Schiff bases by oxidation of primary benzylic or allylic alcohols in the presence of primary amines using Mn(III) complex of polysalicylaldehyde as an efficient and selective heterogeneous catalyst by molecular oxygen
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The present work introduced the new strategy for direct preparation of Schiff base as well as oxime compounds through oxidation of primary benzylic or allylic alcohols in the presence of amines by complexation of Mn(III) to a polymeric Schiff base ligand based on polysalicylaldehyde (PSA-Schiff base-Mn(III) complex). As a new environmentally benign protocol, manganese heterogeneous polymeric catalytic system demonstrated promising oxidation of alcohols in ethanol using molecular oxygen. PSA was synthesized through polycondensation reaction of 2-hydroxy-5-chloromethyl-benzaldehyde and then treated with 2-aminophenol to form polymeric ligand. Average molecular weight of PSA was studied by an analytical method as well as GPC analysis. Formation of the catalyst was characterized step by step by FTIR, UV–Vis, 1H NMR, TGA, CHN and EDX analyses. Loading amounts of metal ions as well as leaching amount of the catalysis were studied by ICP-OES instrument. The catalyst shows up to high yields for oxidation of primary and secondary primary benzylic or allylic alcohols to carbonyl compounds, especially direct imine formation in a mild, inexpensive and efficient method which can be successfully recovered from the reaction mixture and reused for several times without any remarkable reactivity loss. Effect of solvent, temperature, catalyst amount and oxygen donors along with some blank experiments to elucidation of catalyst activity was evaluated in this work. Also chemoselectivity behavior of the catalyst was investigated with some combinations.
- Kazemnejadi, Milad,Shakeri, Alireza,Mohammadi, Mohammad,Tabefam, Marzieh
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p. 1917 - 1933
(2017/08/15)
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- One-pot conversion of cyclohexanol to ?-caprolactam using a multifunctional Na2WO4-acidic ionic liquid catalytic system
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Na2WO4-acidic ionic liquid was used as a simple, ecofriendly, recyclable and efficient catalytic system for the one-pot conversion of cyclohexanol to ?-caprolactam. The effect of the structure of the ionic liquid on the catalytic activity of this system was investigated, and the results revealed that sulfonic acid-functionalized ionic liquids with HSO4?as an anion gave the best results. The highly efficient performance of this catalyst system was attributed to the phase-transfer behavior of the cation of the ionic liquid, the improved coordination of the substrate to bisperoxotungstate during the oxidation reaction, and the stabilization of the intermediate formed during the Beckmann rearrangement.
- Wang, Hefang,Jia, Liyuan,Hu, Rongbin,Gao, Meidan,Wang, Yanji
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- 1,2,4-triazole compound containing oxime carboxylate, and preparation method and application thereof
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The invention discloses a 1,2,4-triazole compound containing oxime carboxylate, and a preparation method and application thereof. The general formula (I) of the compound is described in the specification. In the formula (I), R is selected from a group consisting of a phenyl group, a 4-fluorophenyl group, a 4-chlorophenyl group, a 4-trifluoromethylphenyl group, a 4-nitrophenyl group, a 4-methoxyphenyl group, a 3,4-dimethyoxyphenyl group and a 3,4,5-trimethoxyphenyl group; R1 is a methyl group or ethyl group; and R2 is a methyl group. The compound provided by the invention has good biological activity in inhibition of Xanthomonas axonopodis pv.citri, Ralstonia solanacearum and Xanthomonas oryzae pv.oryzae.
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Paragraph 0020
(2018/02/04)
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- Br?nsted acid catalyzed transoximation reaction: Synthesis of aldoximes and ketoximes without use of hydroxylamine salts
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The transoximation reaction enables the transfer of an oxime to a carbonyl compound and is catalyzed by transoximase in the pupae of the silkworm. Inspired by this bio-synthetic pathway, we achieved the transoximation of oximes to aldehydes and ketones catalyzed by a Br?nsted acid under mild conditions. Hydroxylamine salt, which necessitates a stoichiometric amount of base, was not required. NMR analysis clarified that this reaction proceeded through hydroxylamines generated by the successive hydrolysis of the oxime in situ. In addition, an environmentally benign method for catalytic transoximation was demonstrated in aqueous medium on a one hundred gram scale and the reaction filtrate containing the catalyst was recovered and reused over 10 times.
- Hyodo, Kengo,Togashi, Kosuke,Oishi, Naoki,Hasegawa, Genna,Uchida, Kingo
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supporting information
p. 5788 - 5793
(2016/11/06)
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- Method for preparing 2-nitropropane
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The invention discloses a method for preparing 2-nitropropane, and relates to the technical field of organic compound synthesis. The method comprises the following steps: enabling acetone, ammonia gas or ammonia water, hydrogen peroxide, a solvent and a catalyst to contact, heating till the reaction temperature of 30-100 DEG C, and controlling the reaction pressure to 0.1-0.2MPa to react, thereby obtaining 2-nitropropane, wherein the catalyst is a TS-1 titanium silicalite molecular sieve; the solvent is water; the mole ratio of acetone to ammonia gas or ammonia water is 1:(1-3); the mole ratio of acetone to hydrogen peroxide is 1:(0.5-2); and the mass ratio of acetone to the catalyst is 1:(0.2-0.4). The method disclosed by the invention has the advantages that the conversion rate of acetone is high and the selectivity of 2-nitropropane is good; the method is simple in reaction process, gentle in reaction condition, environment-friendly and easy in industrial production; and development of environment-friendly chemicals is promoted.
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Paragraph 0016-0017
(2017/06/20)
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- Expedient one-pot synthesis of pyrroles from ketones, hydroxylamine, and 1,2-dichloroethane
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2- and 2,3-Substituted pyrroles are readily synthesized in a one-pot procedure from ketones, hydroxylamine hydrochloride, and 1,2-dichloroethane in the KOH/DMSO system (120 °C, 2-4 h), the yields of pyrroles ranging 11-85%. Aliphatic, cycloaliphatic, aromatic, and heteroaromatic ketones tolerate the reaction conditions.
- Trofimov, Boris A.,Mikhaleva, Al'Bina I.,Ivanov, Andrei V.,Shcherbakova, Viktoria S.,Ushakov, Igor A.
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p. 124 - 128
(2015/02/02)
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- A value-added use of volatile turpentine: antifungal activity and QSAR study of β-pinene derivatives against three agricultural fungi
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In consideration of turpentine and its analogues possessing some agricultural biological activity, persistent efforts to take advantage of renewable, abundant natural resources have been made. Three series of derivatives from β-pinene were synthesized and their fungicidal activities against Rhizoctonia solani, Fusarium graminearum, and Botrytis cinerea were investigated. Most of the synthesized compounds exhibited moderate to significant fungicidal activity. Among them, the acylthiourea derivatives from β-pinene showed more promising results than the other compounds. It was worth noting that compounds 7b and 7d displayed excellent fungicidal activity against Rhizoctonia solani, with IC50 values of 2.439 and 1.857 μg mL-1, which was close to or even better than the control triadimenol (1.945 μg mL-1, a commercial fungicide). The structure-activity relationship (SAR) analysis indicated that the compounds with more net positive charge possessed better fungicidal activity. The quantitative structure-activity relationship (QSAR) model (R2 = 0.9879, F = 348.41, S2 = 0.0047) was obtained through the best multi-linear regression. The built model revealed a strong correlation of fungicidal activity against Rhizoctonia solani with the molecular features of the title compounds. Additionally, the SAR and QSAR studies showed that the introduction of an electron-withdrawing group, which can increase the positive charge, was favorable towards the fungicidal activity. These encouraging results may provide an alternative, promising use of β-pinene through the design and exploration of eco-friendly fungicides with low toxicity and high efficiency.
- Li, Jian,Tian, Xiangrong,Gao, Yanqing,Shang, Shibin,Feng, Juntao,Zhang, Xing
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p. 66947 - 66955
(2015/08/24)
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- Direct catalytic synthesis of ε-caprolactam from cyclohexanol using [n-C16H33N (CH3)3]H2PW12O40 as a catalyst
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ε-Caprolactam was synthesized directly from cyclohexanol via a tandem catalytic process using [n-C16H33N(CH3)3]H2PW12O40 as a catalyst. The highly efficient performance of the catalysts is due to the phase-transfer function of cation, improved coordination with peroxotungsten during oxidation and stabilization function of heteropoly anion on the intermediate formed during Beckmann rearrangement. A ε-caprolactam yield of 73.9% was obtained with a cyclohexanol conversion of 97.1% under optimized conditions.
- Wang, Hefang,Hu, Rongbin,Yang, Yongfang,Gao, Meidan,Wang, Yanji
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- Dual nature of polyethylene glycol under microwave irradiation for the clean synthesis of oximes
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Polyethylene glycol (PEG-400 and PEG-600) is an efficient, inexpensive, and recyclable homogeneous medium and catalyst (dual nature) for the clean synthesis of oximes (and aldoximes) under microwave irradiation in the absence of acid and base catalysts. Both aliphatic and aromatic aldehydes/ketones give satisfactory results under microwave irradiation within a short time. Graphical abstract: [Figure not available: see fulltext.]
- Dutta, Papia,Dutta, Arup Kumar,Sarma, Parishmita,Borah, Ruli
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p. 505 - 508
(2014/03/21)
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- Fast alpha nucleophiles: Structures that undergo rapid hydrazone/oxime formation at neutral pH
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Hydrazones and oximes are widely useful structures for conjugate formation in chemistry and biology, but their formation can be slow at neutral pH. Kinetics studies were performed for a range of structurally varied hydrazines, and a surprisingly large variation in reaction rate was observed. Structures that undergo especially rapid reactions were identified, enabling reaction rates that rival orthogonal cycloaddition-based conjugation chemistries.
- Kool, Eric T.,Crisalli, Pete,Chan, Ke Min
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supporting information
p. 1454 - 1457
(2014/04/03)
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- Lewis acidic strength controlled highly selective synthesis of oxime via liquid-phase ammoximation over titanosilicates
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The Lewis acidity of titanosilicates determines the selectivity of the oxime in ammoximation. Higher Lewis acidic strength of Ti active sites could promote free H2O2 to participate in the highly efficient formation of NH2OH by lowering the reaction activation energy for the formation of Ti-OOH species, and thus fundamentally suppress the side reactions of deep oxidation.
- Zhuo, Zuoxi,Wu, Lizhi,Wang, Lei,Ding, Yichun,Zhang, Xiaoqian,Liu, Yueming,He, Mingyuan
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p. 55685 - 55688
(2015/02/19)
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- The mechanism of catalyst deactivation and by-product formation in acetone ammoximation catalyzed by hollow titanium silicalite
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The deactivation mechanism of hollow titanium silicalite (HTS) in aqueous ammoximation of acetone was investigated. Amines and polynitro-compounds, formed by alkaline autocatalytic and oxidative coupling reaction respectively, were determined to be the ma
- Wang, Yi,Zhang, Shengjian,Zhao, Yingxian,Lin, Min
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- Formation of C-O bond via cross-dehydrogenative coupling between isochroman and oxime under metal-free oxidation conditions
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DDQ-mediated C-O bond formation through cross-dehydrogenative coupling (CDC) reaction without any metal catalyst under mild conditions was developed. Series of isochromans and oximes could be employed as substrates, and the products were obtained in good yields. Georg Thieme Verlag Stuttgart New York.
- He, Hua-Feng,Wang, Kai,Xing, Bo,Sheng, Guorong,Ma, Tingxuan,Bao, Weiliang
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supporting information
p. 211 - 214
(2013/03/13)
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- Selective ammoximation of ketones and aldehydes catalyzed by a trivanadium-substituted polyoxometalate with H2O2 and ammonia
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The ammoximation of different ketones and aldehydes to their corresponding oximes catalyzed by K6[PW9 V3O 40]·4H2O was carried out with hydrogen peroxide and ammonia in isopropanol at room temperature. High yields of oximes were obtained in this catalytic system. This catalytic system was proved to be heterogeneous by the ammoximation activity of removal of catalyst and the elemental analysis of the filtrate after reaction. A possible procedure for the ammoximation catalyzed by K6[PW9V3O40] ·4H2O with H2O2 and NH 3·H2O was proposed. The fresh and used catalysts were characterized by IR and 31P MAS NMR, which revealed the good stability of the catalyst.
- Xue, Xiaoling,Song, Fangyuan,Ma, Baochun,Yu, Yongze,Li, Cheng,Ding, Yong
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- Synthesis and antibacterial activity of oxime ester derivatives from dehydroabietic acid
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A series of oxime ester derivatives containing dehydroabietyl group were synthesized from dehydroabietic acid. Their structures were characterized by IR, 1HNMR, MS, and elemental analysis. The preliminary antibacterial activity results indicate that these compounds display extensive anti-bacterial activity against Escherichia coli, Staphyloccocus aureu, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia aerogenes and Staphyloccocus epidermidis. Compounds (5a, 5b, 5c, 5d, 5e, 5f) exhibit excellent anti-bacterial activity against Escherichia coli with the diameter of inhibition zone is 10.91mm, 11.03mm, 12.92mm, 13.48mm, 11.59mm and 11.58mm respectively, compared with the diameter of inhibition zone of 9.66mm of the commercial compound bromogeramine. Furthermore, Compounds(5d) exhibited the same level of antibacterial activity against Staphyloccocus epidermidis when compared with bromogeramine and Ampicillin Na.
- Yan-Jie, Cui,Xiao-Ping, Rao,Shi-Bin, Shang,Jie, Song,Yan-Qing, Gao
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p. 102 - 110
(2013/05/09)
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- METHOD FOR PREPARING 2,3-DIMETHYL-2,3-DINITROBUTANE
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The present invention relates to a method for preparing 2,3-dimethyl-2,3-dinitrobutane (DMNB), which includes the following steps: (1) making titanium-silicate molecular sieve catalyst, acetone, hydrogen peroxide and ammonia contact and react at 65-80° C. to obtain a modified titanium-silicate molecular sieve catalyst; and (2-1) making acetone oxime and hydrogen peroxide contact and react in the presence of the modified titanium-silicate molecular sieve catalyst and water under the conditions of temperature of 60-90° C. and pH of 8-10, and separating DMNB from the reaction products thereof; or (2-2) making acetone, ammonia and hydrogen peroxide contact and react in the presence of the modified titanium-silicate molecular sieve catalyst and water under the conditions of temperature of 60-90° C. and pH of 8-10, and separating DMNB from the reaction products thereof. By the method provided by the present invention, DMNB can be prepared without having to use dangerous chemicals, such as 2-nitropropane, NaH and the like.
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Paragraph 0082; 0083; 0084; 0085; 0086; 0087; 0088; 0089
(2013/07/25)
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- Synthesis and antibacterial activity of oxime ester derivatives containing 16-isopropyl-5,9-dimethyl tetracyclo [10.2.2.01,10.04,9] hexadec-15-ene-5,14- dicarboxyl group
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Acrylpimaric acid (16-isopropyl-5,9- dimethyltetracyclo [10. 2. 2. 0 1,10.04,9]hexadec- 15-ene-5,14-dicarboxylic acid) was prepared by rosin through Diels-Alder addition reaction, then a series of oxime ester derivatives containing acrylpimaryl (16-isopropyl-5,9-dimethyltetracyclo [10.2.2.01,10.04,9]hexadec-15-ene-5,14-dicarboxyl) group were synthesized. Their structures were characterized by IR, 1HNMR, MS, and elemental analysis. The antibacterial activity of these newly synthesized oxime ester derivatives against Gram-negative bacteria and Gram-positive bacteria were also investigated. The results indicate that compounds display extensive anti-bacterial activity against Gram-negative bacteria and Gram-positive bacteria. Especially compounds (4c, 4d, 4f, 4h and 4k) exhibit excellent anti-bacterial activity against Escherichia coli (Gram-negative bacteria). Compared with the diameter of inhibition zone is 9.66mm of the standard compound bromogeramine, which the diameter of inhibition zone is 12.17mm, 10.00mm, 10.33mm, 9.67mm and 9.67mm respectively.
- Li, Jian,Rao, Xiaoping,Shang, Shibin,Gao, Yanqing,Song, Binglei
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experimental part
p. 217 - 222
(2012/04/23)
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- The synthesis of novel oxime ethers and their effects on the senescence of cut carnation flowers
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The high levels of ethylene in plants are involved in a range of harmful effects, such as the senescence of plants and the rotting of fruits. A series of novel oxime ethers were synthesized to counteract the ethylene effects. Their structures were characterized by IR, MS, and 1H NMR, and their effects on the senescence of cut carnation flowers were investigated. The results show that all of the target compounds extended the vase life of cut carnation, especially for compound 3i, which prolonged the vase life of cut carnation flowers to about 11 days, nearly 75% longer vase life compared to the control groups. Most of them were more effective than AgNO3 and aminooxyacetic acid. Springer Science+Business Media B.V. 2011.
- Zeng, Zhen,Jiang, Hong,Zhang, Haoyong,Jiang, Zhenhua
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scheme or table
p. 463 - 470
(2012/05/20)
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- Investigation of the rearrangement in alkyl-bridged bis(carbamoyldiaziridine) derivatives
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The thermal treatment of alkyl-bridged bis(carbamoyldiaziridine) derivatives in toluene at 100 °C led to the formation of new saturated five- and six-membered 1,3-diaza-heterocyclic compounds from ethylene- or propylene-bridged bis(carbamoyldiaziridine) derviatives, respectively. Detailed experimental investigations of this reaction revealed an unprecedented intramolecular eliminative rearrangement, involving the two adjacent diaziridine moieties. The loss of a three-carbon fragment by elimination of acetone during the reaction was confirmed by GC-MS measurements. The products of the rearrangement were fully characterized, and their structures were confirmed by X-ray crystal structure analysis. Furthermore, a reaction mechanism of the eliminative rearrangement was proposed, and the reaction pathway was corroborated by DFT calculations of gas-phase model structures at the B3LYP/6-31G** level. Copyright
- Kamuf, Matthias,Rominger, Frank,Trapp, Oliver
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experimental part
p. 4733 - 4739
(2012/09/22)
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- An efficient one-pot synthesis of oxime ethers from alcohols using triphenylphosphine/carbon tetrachloride
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A convenient and efficient one-pot O-alkylation of oximes from alcohols using triphenylphosphine in carbon tetrachloride is described. In this method, treatment of alcohols with a mixture of triphenylphosphine, carbon tetrachloride, oxime, and DBU in the presence of catalytic amounts of tetrabutylammonium iodide in refluxing acetonitrile regioselectively furnishes the corresponding O-alkyl ethers in good yields. This methodology is highly efficient O-alkylation of oximes with various structurally diverse alcohols. Semiempirical quantum-mechanic calculations (AM1) for unsymmetrical oxime ethers, indicated a lower heat of formation for Z-isomers. Georg Thieme Verlag Stuttgart - New York.
- Soltani Rad, Mohammad Navid,Khalafi-Nezhad, Ali,Karimitabar, Fatemeh,Behrouz, Somayeh
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experimental part
p. 1724 - 1730
(2010/07/08)
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- Oxime Carbamate-Discovery of a series of novel FAAH inhibitors
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A series of novel oxime carbamates have been identified as potent inhibitors of the key regulatory enzyme of the endocannabinoid signaling system, fatty acid amide hydrolase (FAAH). In this Letter, the rationale behind the discovery and the biological evaluations of this novel class of FAAH inhibitors are presented. Both in vitro and in vivo results of selected targets are discussed, along with inhibition kinetics and molecular modeling studies.1.
- Sit,Conway, Charles M.,Xie, Kai,Bertekap, Robert,Bourin, Clotilde,Burris, Kevin D.
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supporting information; experimental part
p. 1272 - 1277
(2010/06/17)
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- Enantioselective synthesis of 2-isoxazolines by a One-flask conjugate addition/oxime-transfer process
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A study was conducted to demonstrate a new catalytic enantioselective method to prepare 5-substituted 2-isoxazolines that applied a small organic catalyst as the source of chirality and enabled the use of different α-β-unsaturated aldehydes as starting materials. The aldehyde and acetone oxime were added to a solution of amine and benzoic acid in toluene at 0 °C. A precooled solution of H2SO4 in MeOH was added and the resulting solution was stirred for 15 minutes at 0 °C after stirring the reaction mixture at 0 °C for the indicated period of time. A saturated aqueous solution of NaHCO3 was added and the mixture was extracted with EtOAc. The combined organic extracts were dried and concentrated, while the residue was purified by flash chromatography to afford the products. The results show that the presence of a strong acid in the reaction mixture induced the formation of similar catalytic species in the reactions.
- Pohjakallio, Antti,Pihko, Petri M.
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supporting information; experimental part
p. 3960 - 3964
(2009/11/30)
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- Silica-gel-confined ionic liquids: A new attempt for the development of supported nanoliquid catalysis
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A new concept of designing and synthesizing highly dispersed ionic-liquid catalysts was developed through physical confinement or encapsulation of ionic liquids (with or without metal complex) in a silica-gel matrix through a sol-gel process. We studied ionic liquids such as EMImBF4, BuMImBF 4, DMImBF4, CMImBF4, BuMImPF6, either with or without [Pd(PPh3)2Cl2] and [Rh(PPh3)3Cl], in a silica-gel matrix (E = ethyl, Bu = butyl M = methyl, D = decyl, C = cetyl and Im = imidazolium). The contents of ionic liquids and loadings of Pd or Rh were 853 wt% and 0.1 - 0.15 wt%, respectively. Analyses of FT-Raman spectra showed that abnormal Raman spectra of the confined ionic liquids were observed in comparison with the bulk and pure ionic liquids. EMImBF4 and BuMImBF4 ionic liquids could be completely washed out from the silica-gel matrix under vigorous reflux conditions, but ionic liquids with larger molecular size, for example, DMImBF4 or CMImBF4, could be confined into the silica-gel nanopores relatively firmly. These results suggested that the ionic liquids were physically confined or encapsulated into the silica gel. The N2 adsorption measurements indicated that the silica-gel skeleton was mesoporous with 50-110 A pore size after the BuMImBF4 ionic liquid was removed completely. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis showed that the silicagel matrix was amorphous and nonuniformly mesoporous. Carbonylation of aniline and nitrobenzene for synthesis of diphenyl urea, carbonylation of aniline for synthesis of carbamates, and oxime transformation between cyclo-hexanone oxime and acetone were used as test reactions for these catalysts. Catalytic activities were remarkably enhanced with much lower amounts of ionic liquids needed with respect to bulk ionic-liquid catalysts or silica-supported ionic-liquid catalysts prepared with simple impregnation, in which the ionic liquid may be deposited as a thin layer on the support. Such unusual enhancement in catalytic activities may be attributed to the formation of nanoscale and high-concentration ionic liquids due to the confinement of the ionic liquid in silica gel; this results in unusual changes in the symmetry and coordination geometry of the ionic liquids.
- Shi, Feng,Zhang, Qinghua,Li, Dongmei,Deng, Youquan
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p. 5279 - 5288
(2007/10/03)
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- Thermal decomposition of O-benzyl ketoximes; role of reverse radical disproportionation
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Thermolyses of seven dialkyl, two alkyl-aryl and two diaryl O-benzyl ketoxime ethers, R1R2C=NOCH2Ph, have been examined in three hydrogen donor solvents: tetralin, 9,10-dihydrophenanthrene, and 9,10-dihydroanthracene. All the oxime ethers gave the products expected from homolytic scission of both the O-C bond (viz., R1R2C=NOH and PhCH3) and N-O bond (viz., R1R2C=NH and PhCH2OH). The yields of these products depended on which solvent was used and the rates of decomposition of the O-benzyl oxime ethers were greater in 9,10-dihydrophenanthrene and 9,10-dihydroanthracene than in tetralin. These results indicated that a reverse radical disproportionation reaction in which a hydrogen atom was transferred from the solvent to the oxime ether, followed by β-scission of the resultant aminoalkyl radical, must be important in the latter two solvents. Benzaldehyde was found to be an additional product from thermolyses conducted in tetralin. This, and other evidence, indicated that another induced decomposition mode involving abstraction of a benzylic hydrogen atom, followed by β-scission of the resulting benzyl radical, became important for some substrates. Participation by minor amounts of enamine tautomers of the oxime ethers was shown to be negligible by comparison of thermolysis data for the O-benzyloxime of bicyclo[3.3.1]nonan-9-one, which cannot give an enamine tautomer, with that of the O-benzyloxime of cyclohexanone.
- Blake, Jessie A.,Ingold, Keith U.,Lin, Shuqiong,Mulder, Peter,Pratt, Derek A.,Sheeller, Brad,Walton, John C.
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p. 415 - 420
(2007/10/03)
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- One-step C=N, C=O bonds cleavage and C=O, C=N bonds formation over supported ionic liquid in water
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At ambient reaction temperature, the silica gel confined ionic liquid catalysts were perfectly combined with water as an effective catalytic system for simultaneous C=N and C=O bonds transformation with a TONs exceeding 300 mol mol-1.
- Li, Dongmei,Shi, Feng,Deng, Youquan
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p. 6791 - 6794
(2007/10/03)
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- BROADSPECTRUM SUBSTITUTED BENZISOXAZOLE SULFONAMIDE HIV PROTEASE INHIBITORS
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The present invention concerns the compounds having the formula N-oxides, salts, stereoisomeric forms, racemic mixtures, prodrugs esters and metabolites thereof.It further relates to their use as broadspectrum HIV protease inhibitors, processes for their preparation as well as pharmaceutical compositions and diagnostic kits comprising them. It also concerns combinations thereof with another anti-retroviral agent, and to their use in assays as reference compounds or as reagents.
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Page/Page column 21
(2008/06/13)
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- Ribavirin-interferon alfa combination therapy for eradicating detectable HCV-RNA in patients having chronic hepatitis C infection
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Ribavirin derivatives represented by formula I wherein at least one of R2, R3 or R5 is a straight or branched chain polyalkylene oxide polymer conjugate, and pharmaceutical compositions containing them as well as their use to treat patients having susceptible viral infections, alone and in combination with a therapeutically effective amount of interferon-alpha are disclosed.
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- Ribavirin-interferon alfa combination therapy for eradicating detectable HCV-RNA in patients having chronic hepatitis C infection
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Ribavirin derivatives represented by the formula II, pharmaceutical compositions containing them as well as methods of using the ribavirin derivatives represented by the formula II for the treatment of susceptible viral infections, for example, chronic hepatitis C infections administrating, the ribavirin derivatives being represented by formula II are disclosed.
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- Ribavirin-interferon alfa combination therapy for eradicating detectable HCV-RNA in patients having chronic hepatitis C infection
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A method for treating a patient having chronic hepatitis C infection to eradicate detectable HCV-RNA involving a combination therapy using a therapeutically effective amount of ribavirin derivative of formula I and a therapeutically effective amount of interferon-alpha for a time period of from 20 up to 80 weeks.
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- Preparation of O-substituted hydroxylammonium salts
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Preparation of O-substituted hydroxylammonium salts of the formula I where R is a C1 -C6 -alkyl or C2 -C6 -alkenyl radical, each of which may be halogen-substituted, and X is chlorine or bromine, by reacting in an integrated process, without isolation of intermediates a) acetone with hydroxylammonium sulfate and sodium hydroxide solution to give acetone oxime; b) treating the solution of acetone oxime thus obtained with sodium hydroxide solution and completely removing water, c) reacting the suspension of the acetone oxime Na salt thus obtained with alkylating agents at from 0.5 to 15 bar and at up to 140° C. to give acetone oxime ethers; and d) cleaving the acetone oxime ethers with acids HX to give the products I, a homogeneous, nonpolar aprotic solvent being used in all process steps a) to d).
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- Nitrosation of ketone dianions
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Nitrosation of α,α'-dianions produced from ketones using a couple of bases was carried out with tert-butyl nitrite(tert-BuONO) in ether, and then two regioisomers of oximes(but notacetone)were obtained simultaneously. The ratio of these regioisomers was remarkably reversed by the addition of hexamethylphosphoric triamide (HMPA).
- Ikeda,Haraguchi,Yukawa,Niiya,Goto
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p. 526 - 528
(2007/10/02)
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