cas 930-22-3, BUTADIENE MONOXIDE | Articles data

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An Amphiphilic (salen)Co Complex – Utilizing Hydrophobic Interactions to Enhance the Efficiency of a Cooperative Catalyst
An amphiphilic (salen)Co(III) complex is presented that accelerates the hydrolytic kinetic resolution (HKR) of epoxides almost 10 times faster than catalysts from commercially available sources. This was achieved by introducing hydrophobic chains that increase the rate of reaction in one of two ways – by enhancing cooperativity under homogeneous conditions, and increasing the interfacial area under biphasic reaction conditions. While numerous strategies have been employed to increase the efficiency of cooperative catalysts, the utilization of hydrophobic interactions is scarce. With the recent upsurge in green chemistry methods that conduct reactions ‘on water’ and at the oil-water interface, the introduction of hydrophobic interactions has potential to become a general strategy for enhancing the catalytic efficiency of cooperative catalytic systems. (Figure presented.).
Solís-Mu?ana, Pablo,Salam, Joanne,Ren, Chloe Z.-J.,Carr, Bronte,Whitten, Andrew E.,Warr, Gregory G.,Chen, Jack L.-Y.
supporting information
p. 3207 - 3213
(2021/06/01)

Discovery of a Cyclic Choline Analog That Inhibits Anaerobic Choline Metabolism by Human Gut Bacteria
The anaerobic conversion of choline to trimethylamine (TMA) by the human gut microbiota has been linked to multiple human diseases. The potential impact of this microbial metabolic activity on host health has inspired multiple efforts to identify small molecule inhibitors. Here, we use information about the structure and mechanism of the bacterial enzyme choline TMA-lyase (CutC) to develop a cyclic choline analog that inhibits the conversion of choline to TMA in bacterial whole cells and in a complex gut microbial community. In vitro biochemical assays and a crystal structure suggest that this analog is a competitive, mechanism-based inhibitor. This work demonstrates the utility of structure-based design to access inhibitors of radical enzymes from the human gut microbiota.
Bollenbach, Maud,Ortega, Manuel,Orman, Marina,Drennan, Catherine L.,Balskus, Emily P.
supporting information
p. 1980 - 1985
(2020/11/09)

Enantioselective Radical-Polar Crossover Reactions of Indanonecarboxamides with Alkenes
Highly efficient asymmetric intermolecular radical-polar crossover reactions were realized by combining a chiral N,N′-dioxide/NiII complex catalyst with Ag2O under mild reaction conditions. Various terminal alkenes and indanonecarboxamides/esters underwent radical addition/cyclization reactions to afford spiro-iminolactones and spirolactones with good to excellent yields (up to 99 %) and enantioselectivities (up to 97 % ee). Furthermore, a range of different radical-mediated oxidation/elimination or epoxide ring-opening products were obtained under mild reaction conditions. The Lewis acid catalysts exhibited excellent performance and precluded the strong background reaction.
Cao, Weidi,Feng, Xiaoming,Liu, Xiaohua,Wu, Wangbin,Xu, Xi,Yu, Han,Zhang, Xiying
supporting information
p. 4846 - 4850
(2020/02/11)

Functionalizable Stereocontrolled Cyclopolyethers by Ring-Closing Metathesis as Natural Polymer Mimics
Whereas complex stereoregular cyclic architectures are commonplace in biomacromolecules, they remain rare in synthetic polymer chemistry, thus limiting the potential to develop synthetic mimics or advanced materials for biomedical applications. Herein we
Alkattan, Mohammed,Prunet, Jo?lle,Shaver, Michael P.
supporting information
p. 12835 - 12839
(2018/09/25)

Precursor effect on the property and catalytic behavior of Fe-TS-1 in butadiene epoxidation
The effect of iron precursor on the property and catalytic behavior of iron modified titanium silicalite molecular sieve (Fe-TS-1) catalysts in butadiene selective epoxidation has been studied. Three Fe-TS-1 catalysts were prepared, using iron nitrate, iron chloride and iron sulfate as precursors, which played an important role in adjusting the textural properties and chemical states of TS-1. Of the prepared Fe-TS-1 catalysts, those modified by iron nitrate (FN-TS-1) exhibited a significant enhanced performance in butadiene selective epoxidation compared to those derived from iron sulfate (FS-TS-1) or iron chloride (FC-TS-1) precursors. To obtain a deep understanding of their structure-performance relationship, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Temperature programmed desorption of NH3 (NH3-TPD), Diffuse reflectance UV–Vis spectra (DR UV–Vis), Fourier transformed infrared spectra (FT-IR) and thermal gravimetric analysis (TGA) were conducted to characterize Fe-TS-1 catalysts. Experimental results indicated that textural structures and acid sites of modified catalysts as well as the type of Fe species influenced by the precursors were all responsible for the activity and product distribution.
Wu, Mei,Zhao, Huahua,Yang, Jian,Zhao, Jun,Song, Huanling,Chou, Lingjun
p. 2103 - 2109
(2017/10/06)

3,4-epoxy-1-butene preparation method
The present invention relates to a 3,4-epoxy-1-butene preparation method. A purpose of the present invention is mainly to solve the problems of low raw material conversion rate, low product yield and serious waste in the prior art. The technical scheme co
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Paragraph 0032-0035

(2017/03/18)

A broadly applicable and practical oligomeric (salen)Co catalyst for enantioselective epoxide ring-opening reactions
The (salen)Co catalyst (4a) can be prepared as a mixture of cyclic oligomers in a short, chromatography-free synthesis from inexpensive, commercially available precursors. This catalyst displays remarkable enhancements in reactivity and enantioselectivity relative to monomeric and other multimeric (salen)Co catalysts in a wide variety of enantioselective epoxide ring-opening reactions. The application of catalyst 4a is illustrated in the kinetic resolution of terminal epoxides by nucleophilic ring-opening with water, phenols, and primary alcohols; the desymmetrization of meso epoxides by addition of water and carbamates; and the desymmetrization of oxetanes by intramolecular ring opening with alcohols and phenols. The favorable solubility properties of complex 4a under the catalytic conditions facilitated mechanistic studies, allowing elucidation of the basis for the beneficial effect of oligomerization. Finally, a catalyst selection guide is provided to delineate the specific advantages of oligomeric catalyst 4a relative to (salen)Co monomer 1 for each reaction class.
White, David E.,Tadross, Pamela M.,Lu, Zhe,Jacobsen, Eric N.
supporting information
p. 4165 - 4180
(2014/06/09)

Catalytic properties of heteropoly compounds in 1,3-butadiene oxidation with hydrogen peroxide
The homogeneous oxidation of 1,3-butadiene (BD) in H2O 2-HPC-CH3CN (HPC = heteropoly compound) solutions has been investigated. The route of the reaction depends on the nature of the metal capable of coordinating with active oxygen in the HPC. The products of radical BD oxidation (acrolein, 3-butene-1,2-diol, 2-butene-1,4-diol, furan) form in the presence of H3+n PMo12 - n V n O40 (n = 1, 2) acids. 3,4-Epoxy-1-butene (EB) and acrolein + furan, which form in equal amounts in the presence of the (n-Bu4N)5PW 11O39Fe(OH) salt, result, respectively, from the electrophilic addition of hydrogen peroxide to BD and from radical BD oxidation on iron-oxygen complexes in the HPC composition. The reaction carried out in the presence of (n-Bu4N)3{PO4[WO(O 2)2]4}, (n-Bu4N)5Na 0.6H1.4PW11O39, or (EMIm) 5NaHPW11O39 yields EB with high selectivity on the reacted BD basis (up to 97%) and H2O2 (about 100%). The formation and conversion of the phosphotungstate peroxo complexes PW n O m α- (n = 2, 3, 4) that are active in BD epoxidation have been investigated by 31PNMR spectroscopy. The role of the tetrabutylammonium and ethylmethylimidazolium cations in the formation of these complexes has been demonstrated.
Kuznetsova,Kuznetsova,Maksimovskaya,Koshcheeva,Utkin
p. 420 - 430
(2013/12/04)

Preparation, characterization and catalytic performance study of La-TS-1 catalysts
Lanthanum (La) was substituted into a titanium silicalite 1 (TS-1) framework via two different synthetic approaches, i.e., in situ hydrothermal synthesis and ultrasonic immersing methods. La inhibited Ti to enter into the TS-1 framework during in situ hydrothermal synthesis, and thus Ti erosion gave rise to poor catalytic activity for butadiene (BD) epoxidation. While catalysts prepared by an ultrasonic immersing method were testified as fine ones by mutually complementary characterization and catalytic tests. Extraframework-La and Si-OH caused by framework-La enhanced the acidity of TS-1. Adequate intensity of acidity aroused from 8 wt% La modified had activated H 2O2 for BD epoxidation rather than promoting the solvolysis reactions of the epoxide. Moreover, interactions between framework-La and the Ti active center via O weakened the [Ti-O] bond, which facilitated active intermediate formation. As a result, H2O2 conversion and utilization, along with vinyloxirane (VO) yield and TON were highly promoted with appropriate content of La modified.
Wu, Mei,Song, Huanling,Chou, Lingjun
p. 23562 - 23570
(2013/11/19)

The positive role of cadmium in TS-1 catalyst for butadiene epoxidation
A series of Cd modified titanium silicalite 1 catalysts with different Cd content (xCd-TS-1, x = 1-15) were successfully prepared by ultrasound impregnation. Epoxidation of butadiene over these catalysts were investigated using hydrogen peroxide as oxidant, which indicated that Cd greatly improve the catalytic performance of TS-1 and the selectivity of epoxide. Various characterization methods including quantum chemical calculation were employed to explore the specific roles of Cd in promoting TS-1 catalytic activity. Theoretical calculation consistently suggested TiO bond were weakened owing to the introduction of Cd, which resulted in the structure of Cd-TS-1 becoming more relaxant. As a consequence, it is favorable to methanol solvent and H 2O2 interacting with the Ti active site to form five-member transition state during reaction. It was observed that catalysts modified with 1-5 wt% Cd presented both high catalytic activity and good reusability. The highest yield of 0.63 mol/L of vinyloxirane (VO) was obtained, while turnover number (TON, determined as the molar VO obtained per molar Ti atom) could reach to 1466.
Wu, Mei,Song, Huanling,Wang, Fang,Chou, Lingjun
p. 207 - 212
(2013/10/08)

Palladium-catalyzed 1,4-addition of carboxylic acids to butadiene monoxide
Palladium complexes catalyze the 1,4-addition of acetic acid to butadiene monoxide to give 4-hydroxybut-2-en-1-yl acetate. The highest 1,4-/1,2-addition selectivity of 18.9 was achieved. The reaction seems to proceed via a Wacker-like mechanism. Copyright
Hamasaki, Akiyuki,Maruta, Shuhei,Nakamura, Aki,Tokunaga, Makoto
supporting information
p. 2129 - 2134
(2012/11/07)

Epoxidation of butadiene over nickel modified TS-1 catalyst
Nickel modified Titanium silicalite 1 (TS-1) catalysts provided an environmentally benign and effective method for butadiene epoxidation. Certain loading of modified Ni in our system significantly promoted TS-1 catalytic activity. The product vinyloxirane
Wu, Mei,Chou, Lingjun,Song, Huanling
experimental part
p. 627 - 636
(2012/08/29)

Epoxidation of butadiene with hydrogen peroxide catalyzed by the salts of phosphotungstate anions: Relation between catalytic activity and composition of intermediate peroxo complexes
Epoxidation of 1,3-butadiene has been studied in acetonitrile solutions of aqueous H2O2 and tetrabutylammonium or 1-ethyl-3-methylimidazolium salts of phosphotungstate anions: [(n-C 4H9)4N]3{PO4[WO(O 2)2]4}, [(n-C4H9) 4N]5Na0.6H1.4[PW11O 39] or [(C2H5)(CH3)C 3H3N2]5NaH[PW11O 39]. The selectivity of the 1,3-butadiene to 3,4-epoxy-1-butene (EpB) conversion attains 97% at nearly 100% efficiency of the H2O 2 consumption. The rate of the EpB formation has been correlated with the solution compositions as found by 31P NMR under the reaction conditions.
Kuznetsova, Lidia I.,Kuznetsova, Nina I.,Maksimovskaya, Raisa I.,Aleshina, Galina I.,Koscheeva, Olga S.,Utkin, Viktor A.
scheme or table
p. 1442 - 1450
(2012/06/18)

On the dual role of N-heterocyclic carbenes as bases and nucleophiles in reactions with organic halides
The synthetic consequences of different basicities, nucleophilicities, and sterics of N-heterocyclic carbenes have been studied in reactions of imidazolin-2-ylidenes with organic halides. Highly nucleophilic and less basic carbenes cleanly gave alkyli-deneimidazolines, the deoxy analogues of Breslow-type intermediates. More basic NHCs engaged in unwanted deprotonation or dehydrohalogenation reactions. Georg Thieme Verlag Stuttgart. New York.
Knappke, Christiane E. I.,Arduengo, Anthony J.,Jiao, Haijun,Neudoerfl, Joerg-Martin,Jacobivonwangelin, Axel
body text
p. 3784 - 3795
(2012/01/11)

ISOSELECTIVE POLYMERIZATION OF EPOXIDES
The present invention provides novel bimetallic complexes and methods of using the same in the isoselective polymerization of epoxides. The invention also provides methods of kinetic resolution of epoxides. The invention further provides polyethers with high enantiomeric excess that are useful in applications ranging from consumer goods to materials.
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(2009/04/25)

Olefin epoxidation with hydrogen peroxide catalyzed by lacunary polyoxometalate [γ-SiW10O34(H2O) 2]4-
The tetra-n-butylammonium (TBA) salt of the divacant Keggin-type polyoxometalate [TBA]4[γ-SiW10O34-(H 2O)2] (I) catalyzes the oxygen-transfer reactions of olefins, allylic alcohols, and sulfides with 30% aqueous hydrogen peroxide. The negative Hammett ρ+ (-0.99) for the competitive oxidation of p-substituted styrenes and the low value of (nucleophilic oxidation)/(total oxidation), Xso = 0.04, for I-catalyzed oxidation of thianthrene 5-oxide (SSO) reveals that a strongly electrophilic oxidant species is formed on I. The preferential formation of trans-spoxide during epoxidation of 3-methyl-1-cyclohexene demonstrates the steric constraints of the active site of I. The I-catalyzed epoxidation proceeds with an induction period that disappears upon treatment of I with hydrogen peroxide. 29Si and 183W NMR spectroscopy and CSI mass spectrometry show that reaction of I with excess hydrogen peroxide leads to fast formation of a diperoxo species, [TBA]4[γ-SiW10O32(O2) 2] (II), with retention of a γ-Keggin type structure. Whereas the isolated compound II is inactive for stoichiometric epoxidation of cyclooctene, epoxidation with II does proceed in the presence of hydrogen peroxide. The reaction of II with hydrogen peroxide would form a reactive species (III), and this step corresponds to the induction period observed in the catalytic epoxidation. The steric and electronic characters of III are the same as those for the catalytic epoxidation by I. Kinetic, spectroscopic, and mechanistic investigations show that the present epoxidation proceeds via III.
Kamata, Keigo,Kotani, Miyuki,Yamaguchi, Kazuya,Hikichi, Shiro,Mizuno, Noritaka
p. 639 - 648
(2007/10/03)

Synthesis of diols from 1,2-epoxy-3-butene
The catalytic hydration of 1,2-epoxy-3-butene was studied. The products of the reaction are 3-butenediol-1,2(BD-1,2) and 2-butenediol-1,4 (BD-1,4). It was shown that the formation of 2-butenediol-1,4 proceeds predominantly in a polar solvent medium in the presence of the catalytic system "nickel iodide (bromide)-tetraethylammonium iodide" at a temperature of 80°C. In the presence of inorganic acids, the main product is 3-butenediol-1,2. Nauka/Interperiodica 2007.
Mel'nik,Srednev,Rybina,Meshechkina,Shevchuk,Danilova
p. 201 - 204
(2008/09/21)

"Cassette" in situ enzymatic screening identifies complementary chiral scaffolds for hydrolytic kinetic resolution across a range of epoxides
(Figure Presented) Put the cassette in: An in situ enzymatic screen can give real-time estimates of the sense and magnitude of enantioselectivity across more than one substrate. Screening identified CoIII-salen catalysts with β-pinene- and α-naphthylalanine-derived chiral scaffolds with broad, yet complementary, substrate specificities. ADH = alcohol dehydrogenase, HL = horse liver, LK = Lactobacillus kefir, salen = (salicylidene) ethylenediamine.
Dey, Sangeeta,Powell, Douglas R.,Hu, Chunhua,Berkowitz, David B.
p. 7010 - 7014
(2008/09/17)

Silver-containing catalysts for the reaction of substrates with c-c-double bonds
The present invention relates to a silver-containing catalyst system, which can be applied for the reaction of substrates with at least one C—C-double bond with at least one oxygen-containing or oxygen-supplying component with formation of at least one epoxide. The silver-containing catalyst according to the invention is characterized in that its activity as well as its selectivity is significantly increased with respect to the target product compared with the silver-containing catalysts of the state of the art, as a consequence of the process for the manufacture according to the invention, in which the synthesis of a silver-amine complex is carried out in absence of light and at temperatures below room temperature.
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(2008/06/13)

Enantioselective ring opening of epoxides with cyanide catalysed by halohydrin dehalogenases: A new approach to non-racemic β-hydroxy nitriles
Halohydrin dehalogenases (HheA, HheB and HheC) were found to efficiently catalyse a carbon-carbon bond forming reaction between terminal aliphatic epoxides and cyanide, yielding β-hydroxy nitriles. With all three enzymes nucleophilic ring opening of epoxi
Elenkov, Maja Majeric,Hauer, Bernhard,Janssen, Dick B.
p. 579 - 585
(2007/10/03)

Enantioselective synthesis of an all-syn four vicinal fluorine motif
Alkanes bearing multiple vicinal fluorine atoms at adjacent stereocenters may be considered intermediate between alkanes and perfluoroalkanes, and as a class, their chemistry and behavior remain to be explored. We report here a stereoselective synthesis o
Hunter, Luke,O'Hagan, David,Slawin, Alexandra M. Z.
p. 16422 - 16423
(2007/10/03)

Highly active chiral ruthenium catalysts for asymmetric cross- and ring-opening cross-metathesis
Metathesis takes sides: The scope of asymmetric metathesis has been expanded with the use of chiral ruthenium catalysts for asymmetric ring-opening cross-metathesis and for the first example of an asymmetric cross-metathesis (see scheme, TIPS = triisoprop
Berlin, Jacob M.,Goldberg, Steven D.,Grubbs, Robert H.
p. 7591 - 7595
(2008/02/01)

METHOD FOR THE PRODUCTION OF BISEPOXIDES AND DITHIOLS
The invention relates to a method for the production of bisepoxides, characterised in that a conjugated diene of formula (I) is reacted with at least one peroxide with the application of up to 4 equivalents of peroxide per C-C double bond, where R1 is selected from hydrogen and C1-C12 alkyl, unsubstituted or substituted with one or several SH or OH groups, in the presence of a catalyst, obtained by the bringing into contact of at least one manganese compound, selected from A2MnX4, AMnX3, MnY, MnX2 and MnX3 with at least one ligand L, of general formula (II), whereby the variables have the following definitions: X may be the same or different and is selected from monovalent anions, Y is a divalent anion, A is selected from alkali metals and optionally alkylated ammonium, R2 may be different or preferably the same and selected from C1-C20 alkyl and at least one co-ligand, derived from monocarboxylic acids, di- or poly-carboxylic acids or diamines.
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(2008/06/13)

Heteropoly blue as a reaction-controlled phase-transfer catalyst for the epoxidation of olefins
A new reaction-controlled phase-transfer catalyst system has been designed and synthesized. In this system, heteropoly blue, [C7H 7N(CH3)3]3PMo4O 16, is used for the catalytic epoxidation of olefins with H 2O2 as the oxidant. In this system, the catalyst not only can be recovered, like heterogeneous catalyst, but also acts as a homogeneous catalyst. The main products are epoxide of olefins and H2O; no co-product forms. The system exhibits high conversion and selectivity as well as excellent catalyst stability. 31PNMR spectra, UV-vis spectra, and infrared spectra are used to analyze the reason for the phase transfer of the catalyst, indicating that the change of structure leads to the formation of reaction-controlled phase-transfer catalyst.
Mingqiang, Li,Xigao, Jian
p. 1575 - 1579
(2007/10/03)

Catalyst-free gas-phase epoxidation of alkenes
Butadiene, styrene, cyclohexene, allyl acetate, methyl methacrylate, and allyl alcohol were epoxidized in a gas-phase reaction in the absence of a catalyst. The applied oxidizing agent is ozone. With exception of allyl alcohol (selectivity to glycidol: 58%), the selectivity to the corresponding epoxide ranged from 88 to 97%. For acrylonitrile, there was no measureable conversion. Copyright
Berndt, Torsten,Boege, Olaf
p. 584 - 585
(2007/10/03)

Method for abatement of waste oxide gas emissions
The methods of the present invention relate to reducing and eliminating waste oxide gas emissions, produced by a first industrial process, by utilizing the emissions in a second industrial process that either is benefited by or tolerates the components of the waste oxide gas stream. These methods are applicable to numerous combinations of first industrial processes and second industrial processes.
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(2008/06/13)

The selective epoxidation of conjugated olefins containing allylic substituents and epoxidation of propylene in the presence of butadiene
The epoxidation of isoprene (2-methyl-1,3-butadiene) and piperylene (1,3-pentadiene), both conjugated olefins containing allylic methyl groups, has been conducted using conventional, CsCl-promoted, Ag/α-Al 2O3 catalysts. Selectivities to the allylic olefin epoxide isomers are over 20% and are much higher than expected due to the presence of the conjugated olefin structure. The epoxidation of propylene over the same catalyst under the same conditions is only 2.5%. The epoxidation of propylene in the presence of butadiene also yields PO in much higher selectivities. The presence of as little as 1% C4H6 in the reaction feedstream increases the selectivity to PO from 2.5% to over 40% at the expense of overall activity for C3H6 conversion. The upper limit of selectivity to PO in the presence of C4H6 appears to be approximately 50%, suggesting an upper limit for the effectiveness of this methodology. Epoxidation of C4H6 alone on similar Ag catalysts indicates that the consecutive reaction of EpB to CO 2/H2O is strongly limited by the presence of excess C 4H6 in the feedstream. In addition, the selectivity to EpB is directly proportional to the amount of C4H6 in the reaction feed stream. Selectivities >90% are obtained only when there is sufficient C4H6 in the reaction feedstream to control the concentration of the reactive Ag-O surface. For C4H6 epoxidation, all CO2/H2O is formed by a consecutive reaction pathway from EpB; there is no parallel pathway for the direct formation of CO2/H2O from C4H6. Using the selective epoxidation of C4H6 as the model for understanding the enhancement in selectivity for allylic olefin epoxide formation, the most likely reason for improved selectivities is that strongly adsorbed C4H6 (or other conjugated olefins) limits the ensemble size of contiguous Ag-O surface sites. These ensembles are too small for PO combustion, but not too small for PO formation.
Monnier, John R.,Peters, Kimberly T.,Hartley, Gary W.
p. 374 - 380
(2007/10/03)

Surface-modified mixed oxides containing noble metal and titanium for the selective oxidation of hydrocarbons
This invention relates to a process for the production of a composition containing gold and/or silver particles, mixed oxides containing titanium and silicon which have been surface-modified, to the compositions producible in this process and to the use thereof in processes for the selective oxidation of hydrocarbons in the presence of oxygen and a reducing agent. The catalytically active compositions exhibit constantly high selectivities and productivities.
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(2008/06/13)

Synthesis of Cyclic Organic Carbonates from C3-C16 Epoxides
Cyclic organic carbonates were prepared from epoxides (derivatives of C3-C16 olefins, C4 and C8 dienes, styrene; epichlorohydrin) in the presence of a catalytic system consisting of CoCl2 · 6H2O and dimethylformamide.
Rybina,Srednev,Bobyleva
p. 842 - 843
(2007/10/03)

Extensively stereodiversified scaffolds for use in diversity-oriented library synthesis
Figure presented The syntheses of stereodiverse libraries of 12 and 19 are reported, where each asterisk represents an independently varied stereocenter. These scaffolds provide additional templates for investigations of geometric diversity in library syn
Gierasch, Tiffany Malinky,Shi, Zhangjie,Verdine, Gregory L.
p. 621 - 624
(2007/10/03)

Highly selective hydrolytic kinetic resolution of terminal epoxides catalyzed by chiral (salen)CoIII complexes. Practical synthesis of enantioenriched terminal epoxides and 1,2-diols
The hydrolytic kinetic resolution (HKR) of terminal epoxides catalyzed by chiral (salen)CoIII complex 1·OAc affords both recovered unreacted epoxide and 1,2-diol product in highly enantioenriched form. As such, the HKR provides general access to useful, highly enantioenriched chiral building blocks that are otherwise difficult to access, from inexpensive racemic materials. The reaction has several appealing features from a practical standpoint, including the use of H2O as a reactant and low loadings (0.2-2.0 mol %) of a recyclable, commercially available catalyst. In addition, the HKR displays extraordinary scope, as a wide assortment of sterically and electronically varied epoxides can be resolved to ≥ 99% ee. The corresponding 1,2-diols were produced in good-to-high enantiomeric excess using 0.45 equiv of H2O. Useful and general protocols are provided for the isolation of highly enantioenriched epoxides and diols, as well as for catalyst recovery and recycling. Selectivity factors (krel) were determined for the HKR reactions by measuring the product ee at ca. 20% conversion. In nearly all cases, krel values for the HKR exceed 50, and in several cases are well in excess of 200.
Schaus, Scott E.,Brandes, Bridget D.,Larrow, Jay F.,Tokunaga, Makoto,Hansen, Karl B.,Gould, Alexandra E.,Furrow, Michael E.,Jacobsen, Eric N.
p. 1307 - 1315
(2007/10/03)

Deuterium kinetic isotope effects in butadiene epoxidation over unpromoted and Cs-promoted silver catalysts
The kinetic isotope effects (KIE) in the epoxidation of butadiene over both unpromoted and Cs-promoted catalysts were studied using selectively deuterium-labeled isotopomers of 1,3-butadiene (CD2CDCDCD2, CD2CHCHCD2, and CH2CDCDCH2) as feed reactants. On unpromoted silver catalysts, 3,4-epoxy-1-butene formation was characterized by an inverse KIE that results from a primary effect in total oxidation to CO2. These KIE were only significant for butadiene isotopomers that are D-labeled in the 1- and 4-positions, indicating that combustion was initiated by cleavage of a terminal C-H bond. In analogous fashion to previous KIE studies for the epoxidation of ethylene, the observed KIE could be explained by a reaction scheme in which partial and total oxidation products were generated from a common C4H6(ads) surface intermediate. This scheme was also consistent with previous surface science experiments, suggesting that the C4H6O(ads) intermediate could be a surface oxametallacycle. The results of KIE experiments performed over Cs-promoted silver catalysts were in accord with the proposed reaction scheme and showed that the function of the Cs promoter could be to lower the activation energy for epoxy-butene formation from the C4H6O(ads) species.
Barteau,Monnier,Medlin
p. 71 - 76
(2007/10/03)

Synthesis and characterization of oligodeoxynucleotides containing an N1 β-hydroxyalkyl adduct of 2′-deoxyinosine
Hydroxyethyl adducts arising by the reactions of simple epoxides at the N1 position of adenine nucleosides can deaminate to give the inosine analogues which, if formed in DNA, are suspected of being highly mutagenic. A method has been developed for synthesis of oligonucleotides containing N1-adducted 2′-deoxyinosines. The 2′-deoxyinosine adduct of 3,4-epoxy-1-butene was prepared from (±)-4-acetoxy-3-bromo-1-butene and tetraisopropyldisiloxanediyl-protected 2′-deoxyinosine with base. The 2′-deoxyinosine derivative was then incorporated into the oligodeoxynucleotide sequence 5′-d(CGGACXAGAAG)-3′ (X = N1-(1-hydroxy-3-buten-2-yl)-2′-deoxyinosine).
Kowalczyk,Harris,Harris
p. 746 - 753
(2007/10/03)

Use of oxygen-18 to determine kinetics of butadiene epoxidation over Cs-promoted, Ag catalysts
Kinetic isotope effect (KIE) data have been measured using 18O2 for butadiene epoxidation over Cs-promoted, supported Ag catalysts. These show that the rate-limiting step for butadiene epoxidation is dissociation of a molecular oxygen species (O2)-1 on a vacant Ag surface site. Comparisons have been made between the experimentally measured KIE values and calculated KIE values for reaction steps (other than O-O dissociation) involving bond-making or bond-breaking steps in which oxygen is involved. In all these instances the calculated KIE values are much lower than the KIE actually observed. This study marks the first instance where 18O2 has been used at steady-state olefin epoxidation conditions to confirm the nature of the oxygen active in olefin epoxidation. The O-18 results in this study also directly support the current belief that atomic oxygen, and not a molecular oxygen species, is the active form of oxygen that reacts with olefins to form olefin epoxides. Finally, comparison of the kinetics for butadiene epoxidation with the kinetics for ethylene epoxidation shows that the rate-limiting steps for the two reactions are different. For ethylene epoxidation, the surface reaction between adsorbed ethylene and adsorbed oxygen is considered to be the limiting step, while dissociation of molecular oxygen dissociation is rate limiting for butadiene epoxidation.
Monnier, John R.,Medlin,Barteau
p. 362 - 368
(2007/10/03)

Highly active oligomeric (salen)Co catalysts for asymmetric epoxide ring-opening reactions
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Ready,Jacobsen
p. 2687 - 2688
(2007/10/03)

Ultraselective epoxidation of butadiene on Cu{111} and the effects of Cs promotion [6]
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Cowell, James J.,Santra, Ashok K.,Lambert, Richard M.
p. 2381 - 2382
(2007/10/03)

PROCESSES FOR THE PREPARATION OF ORGANIC DIESTERS
The present invention relates a method of preparing an organic diester which comprises a first step (1) whom a diolefin and a peracid compound are allowed to react to synthesize a monoepoxide, a second step (2) wherein said synthesized monoepoxide is allowed to react with water and carboxylic acid and a third step (3) where the synthesized compounds are allowed to react with an acid anhydride. The present invention also relates to a method of preparing an organic diester wherein in the second step (2), the molar ratio of water and carboxylic acid added into monoepoxide is more than 2 and not more than 20, to an organic diester preparing method wherein monoepoxide is allowed to react with water in the second step (2) and to a method of preparing an organic diester wherein in the second step (2), water and carboxylic acid are removed from the synthesized product and recycled to be used again in said second step (2). The purpose of the present invention is to provide a method of preparing an organic diester having a good selectivity a producing few impurities and using diolefin as a starting material. In the second step (2), when water and carboxylic acid are recycled and used again, it is possible to reduce the load of dumping water and particularly, when 1, 3-butadiene is used as diolefin, acetic acid is used as carboxylic acid and acetic anhydride is used as an acid anhydride it is also possible to reduce the use amount of acetic acid.
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(2008/06/13)

Products of the gas-phase reactions of 1,3-butadiene with OH and NO3 radicals
1,3-Butadiene is released into the atmosphere from several sources, e.g., combustion sources, and is listed as a hazardous air pollutant under the CAAA. It reacts with OH radicals, NO3 radicals, and O3 in the atmosphere. The products formed from the reactions of 1,3-butadiene with OH radicals (in the presence of NO) and NO3 radicals were identified and quantified by GC, in situ FTIR absorption spectroscopy, and in situ atmospheric pressure ionization tandem MS (API-MS). Formaldehyde, acrolein, and furan were identified and quantified from the OH radical-initiated reaction, with formation yields of 0.62, 0.58, and 0.03-0.04, respectively. Organic nitrates had an estimated yield of 0.07. API-MS analyses showed that these organic nitrates were mostly the hydroxynitrate HOCH2- CH=CHCH2ONO2 and/or its isomers. API-MS analyses revealed the formation of a hydroxycarbonyl with the C4H6O2 formula, ascribed to HOCH2CH = CHCHO and/or its isomers. The main products of the NO3 radical-initiated reaction were organic nitrates. API-MS analyses indicated the formation of 1,2-epoxy-3-butylene, acrolein, and unsaturated C4-hydroxycarbonyls, carbonyl nitrates, hydroxynitrates, and nitrooxyhydroperoxides. The API-MS and API-MS/MS analyses were consistent with the FTIR data, as well as from those of Barnes et al. (1990) and Skov et al. (1992) showing the formation of acrolein. Detailed reaction mechanisms were discussed.
Atkinson,Alvarado,Arey,Tuazon,Arey,Aschmann
p. 3586 - 3595
(2007/10/03)

Rearrangement of 3,4-epoxy-1-butene over lithium phosphate
Rearrangement of 3,4-epoxy-1-butene over lithium phosphate involves ring opening at the side nearest to the vinyl group and yields trans-crotonaldehyde with a selectivity exceeding 90%. The mechanism of this rearrangement is discussed. 1998 MAHK Hayka/Interperiodica Publishing.
Srednev,Yas'kina,Moskvichev,Egorova,Shutova
p. 968 - 970
(2007/10/03)

Process for the synthesis of 2-butene -1,4-diesters
Process for the synthesis of 2-butene-1,4-diesters starting from 1,3-butadiene which comprises: a) the epoxidation, at pH of between 5 and 7, of a double bond of butadiene, by reaction with H2O2, in the presence of titanium silicalite as catalyst; and b) the regioselective esterification of the monoepoxide thus obtained.
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(2008/06/13)

Modelling of processes of hydroperoxide epoxidation of olefins. Reaction of butadiene with tert-amyl hydroperoxide
An investigation has been made of the general relationships governing the epoxidation of butadiene by organic hydroperoxides (TAHP, TBHP, IPBHP, EBHP) with catalysis by molybdenyl propylene glycolate, and a detailed study has been made of the kinetics of the reaction for tert-amyl hydroperoxide. A mathematical model of the process has been developed, adequately describing the experiment with variation in [TAHP]0 from 0·5 to 1·5 mole/l and in [Cat]0 from 3 to 8 × 10-4 mole/l at a temperature of 110°C, and taking account of the change in activity of the catalyst as a function of [Cat] and [ROOH]0. The complex influence of additions of an alcohol, which inhibits the epoxidation rate, but at the same time increases the proportion of the active form of the catalyst, has been explained. The generality of the effects observed for all the examined reactions of hydroperoxide oxidation has been confirmed, and also the need to allow for change in the state of the catalyst in the solution during modelling of these processes.
Akhmed'yanova,Liakumovich,Litvintsev,Monayenkov,Sapunov,Karpov,Surovtsev
p. 83 - 92
(2007/10/03)

Regio- and enantio-selective catalytic epoxidation of conjugated dienes
The regio-and enantio-selective catalytic epoxidation of conjugated aliphatic dienes have been studied using a variety of achiral and chiral manganese salen complexes and sodum hypochlorite or iodosylbenzene as the terminal oxidant.The catalysts show a preference for the less substituted alkene in most of the dienes studied, and in some cases a regioselectivity of 100percent is found.The regioselectivity is dependent on the terminal oxidant applied.The enantiomeric excess (ee) obtained varies for the different conjugated dienes and the ee is generally highest for internal alkenes, where an ee of up to 71percent is observed, whereas 48percent is the highest observed ee for the less substituted alkenes.The ee is also dependent on the terminal oxidant applied.The regio- and enantio-selectivity have also been studied for different 1-(para-substituted phenyl)buta-1,3-dienes, but no regio- and enantio-selectivity dependence on the different subsituents are observed.A competitive epoxidation experiment with styrene and 1-phenylbuta-1,3-diene shows that the latter is the most reactive and the difference in reactivity is discussed on the basis of frontier orbitals of the two systems.The electronic structure of the oxo-manganese salen intermadiate is investigated using INDO/1 calculations and it is found that the triplet state is the most stable state of the intermediate.Based on the electronic structure of the oxo-maganese salen intermediate a mechanism of the oxygen transfer step to the conjugated diene is proposed.
Rasmussen, Kaare G.,Thomsen, Dorte S.,Joergensen, Karl Anker
p. 2009 - 2018
(2007/10/02)

Synthesis of enantiomerically pure 3-butene-1,2-diol derivatives via a Sharpless asymmetric epoxidation route
A short enantiospecific synthesis of the butenediol monotosylates (1,2), the epoxybutanediol monotosylates (3,4) and the epoxybutenes (5,6) is described.
Neagu,Hase
p. 1629 - 1630
(2007/10/02)

Visible Light Induced Reactions of NO2 with Conjugated Dienes in a Low-Temperature Ar Matrix
Visible light induced oxygen atom transfer from NO2 to conjugated dienes has been investigated in a low-temperature Ar matrix, where the dienes are 1,3-butadiene (BD), 2-methyl-1,3-butadiene (isoprene), and 2,3-dimethyl-1,3-butadiene (DMB).In each diene/NO2/Ar system, the corresponding nitrite radical, oxirane, aldehyde, and NO were obtained as the photochemical reaction products.The reactions are initiated by the formation of undetecteable short-lived oxirane biradical and NO due to visible light induced O atom transfer from NO2 to the conjugated dienes. (1) The recombination of oxirane biradicals and neighboring NO gives the nitrite radicals as the photochemical intermediate. (2) The ring closure of the biradicals leads to the formation of oxiranes. (3) The intramolecular H atom transfer of biradicals leads to the formation of aldehydes.The visible photolysis of the nitrite radicals gives rise to oxirane, aldehyde, and NO.The reaction rates are derived by measuring the absorbance changes of the products upon the 582-nm irradiation.The methyl substituent effect on the reactivity is discussed.
Tanaka, Nobuaki,Kajii, Yoshizumi,Shibuya, Kazuhiko,Nakata, Munetaka
p. 7048 - 7053
(2007/10/02)

Regioselective Monoepoxidation of 1,3-Dienes Catalysed by Transition-metal Complexes
A procedure for regioselective monoepoxidation of mainly the less substituted double bond of 1,3-dienes with sodium hypochlorite or iodosylbenzene using various metal complexes as catalysts is presented; the results obtained are different from those found when applying the usual epoxidation reagents.
Thomsen, Dorte S.,Schioett, Birgit,Jorgensen, Karl Anker
p. 1072 - 1074
(2007/10/02)

Process for the production of high energy materials
A process for the production of a high energy nitrate ester involves reacting, in an inert organic solvent, a heterocyclic compound, selected from oxiranes, oxetanes, N-substituted aziridines and N-substituted azetidines, with either N2 O4 or N2 O5, and when the compound is reacted with N2 O4, oxidizing the O- or N-nitrate substituents or substituent in the product to O- or N-nitrate substituent or substituents. The remaining ring carbon atoms on the heterocyclic compound may be substituted or unsubstituted. Preferred substituent groups for the C and/or N ring atoms on the compound include alkyl, cyanoalkyl, haloalkyl, nitroalkyl, and substituted aryl. Several novel nitrate ester are also provided, including nitrated derivatives of polybutadiene, in which between 1% and 25% of the carbon atoms in the polymer are substituted by vicinal nitrate ester (--ONO2) groups.
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(2008/06/13)

A process for the production of high energy material
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(2008/06/13)

Novel (α,β-Epoxyalkyl)lithium Reagents via the Lithiation of Organyl-Substituted Epoxides
A series of epoxides bearing unsaturated organyl groups attached directly to the epoxy group was found to have sufficient kinetic acidity to undergo clean lithiation at low temperatures.Epoxides of the type is aryl, vinylic, acetylenic, alkoxycarbonyl, or cyano, were smoothly converted into by either t-BuLi or LDA in the temperature range of -80 to -115 deg C.The resulting (α,β-epoxyalkyl)lithium reagents could be transformed into a variety of substituted epoxides, such as R2C-CE(Un)-O, where E = D, R3Si, R3Sn, R, RCO, CO2H, or COH(R)2.In cases where Un is acyl, addition to the carbonyl, rather than lithiation, occurred preferentially.Attempted lithiations of aziridines and thiiranes led to extrusion of nitrogen and sulfur, respectively.Even the relatively stable intermediates generated at -90 deg C underwent carbenoid-like decomposition at higher temperatures to yield isomerization and intermolecular-insertion products.Observation of these processes gives direct corroboration of reaction mechanisms proposed for the base-promoted isomerizations of epoxides.
Eisch, John J.,Galle, James E.
p. 4835 - 4840
(2007/10/02)

Synthesis and Insecticidal Activity of Oxazaphospholidines, Oxathiaphospholanes, and Thiazaphospholidines
Fifty-five new five-membered cyclic organophosphorus compounds including oazaphospholidines, thiazaphospholidines, and oxathiaphospholanes were synthesized, which have substituents at 4- or/and 5-positions besides at the 2-position.The thiazaphospholidines showed the highest insecticidal activity followed by oxathiaphospholanes and oxazaphospholidines.The position preference of substituents in insecticidal activity was most obvious in the oxazaphospholidines.It was preferable for insecticidal activity to have the substituent near the more basic atom: the 4-position for thiazaphospholidine and oxazaphospholidine, the 5-position for oxathiaphospholane, with the exception of 4- or 5-phenyl oxazaphospholidine.
Wu, Shao-Yong,Hirashima, Akinori,Takeya, Ryuko,Eto, Morifusa
p. 2911 - 2918
(2007/10/02)

HETEROCYCLIZATION OF 1-ACETOXY-4-HALO-SUBSTITUTED 2-BUTENES IN THE PRESENCE OF ALKALI
The reaction of 1-acetoxy-4-halo-substituted 2-butenes with potassium hydroxide was studied.It was established that trans-1,4-dihaloacetates form α-oxides of 1,3-dienes, whereas the corresponding cis isomers form 2,5-dihydrofuran derivatives.It was observed that the acetyl group in these compounds facilitates, as compared with halovinylhydrins, the formation of the corresponding heterocycles under the conditions described.
Gevorkyan, A. A.,Kazaryan, P. I.,Avakyan, S. V.
p. 1088 - 1090
(2007/10/02)