- 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)
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- Palladium-catalyzed stereoselective (3 + 2) cycloaddition of vinylethylene carbonates with cyclicN-sulfonyl ketimines
-
A diastereoselective (3 + 2) cycloaddition ofN-sulfonyl ketimines with vinylethylene carbonates (VECs) in the presence of Pd2dba3·CHCl3and PPh3has been developed. The reaction of various substituted VECs and diverse cyclicN-sulfonyl ketimines proceeded smoothly under mild conditions, giving highly functionalized oxazolidine frameworks in good to excellent yields with moderate to good diastereoselectivities. With the use of spiroketal-based diphosphine SKP as a chiral ligand, an asymmetric version of the current (3 + 2) cycloaddition was achieved, and chiral products were obtained in >99% ee in most cases.
- Gao, Xing,Zhu, Dongyu,Jiang, Feng,Liao, Jianning,Wang, Wei,Wu, Yongjun,Zheng, Lufei,Guo, Hongchao
-
supporting information
p. 4877 - 4881
(2021/06/16)
-
- Preparation method of vinylethylene sulfite
-
The invention belongs to the field of additives, and particularly relates to a preparation method of vinylethylene sulfite. The invention discloses a preparation method of vinylethylene sulfite, whichcomprises the following step: reacting 3-butylene-1,2-diol with thionyl chloride to obtain vinylethylene sulfite. The preparation method has the advantages of simple operation, easily available raw materials, greenness, environmental protection, and great implementation value and social and economic benefits.
- -
-
Paragraph 0033-0034
(2021/03/31)
-
- Olefin reaction in the catalyst and the olefin production
-
PROBLEM TO BE SOLVED: To provide a catalyst for obtaining an olefin in high selectivity with a vicinal diol as a raw material.SOLUTION: A catalyst for olefination reaction for use in a reaction to produce an olefin by a reaction of a polyol, having two adjacent carbon atoms each having a hydroxy group, with hydrogen comprises: a carrier; at least one oxide selected from the group consisting of oxides of the group 6 elements and oxides of the group 7 elements supported on the carrier; and at least one metal selected from the group consisting of silver, iridium, and gold supported on the carrier.SELECTED DRAWING: None
- -
-
Paragraph 0145-0146; 0149
(2020/10/31)
-
- Asymmetric Synthesis of N-Fused 1,3-Oxazolidines via Pd-Catalyzed Decarboxylative (3+2) Cycloaddition
-
Efficient synthesis of optically active N-fused 1,3-oxazolidines containing quaternary and tertiary stereocenters was achieved via Pd-catalyzed asymmetric (3+2) cycloadditions of sulfamate-derived cyclic imines and vinylethylene carbonates. Using a chiral phosphoramidite ligand, the cycloadditions proceeded effectively providing sulfamidate-fused 1,3-oxazolidines in high yields (up to 96%) with stereoselectivities (up to 25:1 dr; >99% ee). Additionally, the scale-up reaction and further transformations of the product were also achieved demonstrating the synthetic utility toward the construction of useful heterocycles such as chiral oxazoline bearing a quaternary stereocenter. (Figure presented.).
- Ahn, Hye-In,Cho, Ho-Jun,Kim, Ju Hyun,Park, Jong-Un,Xuan, Zi
-
supporting information
(2020/04/22)
-
- Pd-Catalyzed Decarboxylative Olefination: Stereoselective Synthesis of Polysubstituted Butadienes and Macrocyclic P-glycoprotein Inhibitors
-
The efficient and stereoselective synthesis of polysubstituted butadienes, especially the multifunctional butadienes, represents a great challenge in organic synthesis. Herein, we wish to report a distinctive Pd(0) carbene-initiated decarboxylative olefination approach that enables the direct coupling of diazo esters with vinylethylene carbonates (VECs), vinyl oxazolidinones, or vinyl benzoxazinones to afford alcohol-, amine-, or aniline-containing 1,3-dienes in moderate to high yields and with excellent stereoselectivity. This protocol features operational simplicity, mild reaction conditions, a broad substrate scope, and gram-scalability. Notably, a structurally unique allylic Pd(II) intermediate was isolated and characterized. DFT calculation and control experiments demonstrated that a rare Pd(0) carbene intermediate could be involved in this reaction. Moreover, the polysubstituted butadienes as novel building blocks were unprecedentedly assembled into macrocycles, which efficiently inhibited the P-glycoprotein and dramatically reversed multidrug resistance in cancer cells by 190-fold.
- Chen, Xiangyang,Hao, Jiping,Houk, K. N.,Li, Yingzi,Lou, Liguang,Quan, Haitian,Song, Bichao,Wang, Lu,Xia, Yuanzhi,Xie, Peipei,Xu, Zhongliang,Yang, Weibo
-
supporting information
p. 9982 - 9992
(2020/06/27)
-
- Transfer hydrogenation of cyclic carbonates and polycarbonate to methanol and diols by iron pincer catalysts
-
Herein, we report the first example on the use of an earth-abundant metal complex as the catalyst for the transfer hydrogenation of cyclic carbonates to methanol and diols. The advantage of this method is the use of isopropanol as the hydrogen source, thus avoiding the handling of flammable hydrogen under high pressure. The reaction offers an indirect route for the reduction of CO2 to methanol. In addition, poly(propylene carbonate) was converted to methanol and propylene glycol. This methodology can be considered as an attractive opportunity for the chemical recycling of polycarbonates.
- Liu, Xin,De Vries, Johannes G.,Werner, Thomas
-
p. 5248 - 5255
(2019/10/11)
-
- A versatile biobased continuous flow strategy for the production of 3-butene-1,2-diol and vinyl ethylene carbonate from erythritol
-
A versatile, tunable and robust continuous flow procedure for the deoxydehydration (DODH) of biobased erythritol toward 3-butene-1,2-diol is described. The procedure relies on specific assets of multistep continuous flow processing. Detailed mechanistic and computational studies on erythritol show that either 3-butene-1,2-diol or butadiene are obtained in high selectivity and yield on demand, as a function of the DODH reagent/substrate ratio and of the process parameters. Short reaction times (1-15 min) at high temperature (225-275 °C) and moderate pressure are reported. 3-Butene-1,2-diol is then further converted downstream into its corresponding carbonate, i.e. 4-vinyl-1,3-dioxolan-2-one (vinyl ethylene carbonate), an important industrial building block. The carbonation step uses a supported organocatalyst, and could be directly concatenated to the first DODH step. This unprecedented procedure also relies on a unique combination of on- and off-line analytical protocols for reaction monitoring and product quantification, and offers a biobased strategy toward important industrial building blocks otherwise petrosourced.
- Tshibalonza, Nelly Ntumba,Gérardy, Romaric,Alsafra, Zouheir,Eppe, Gauthier,Monbaliu, Jean-Christophe M.
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supporting information
p. 5147 - 5157
(2018/11/26)
-
- Enzyme-mediated enantioselective hydrolysis of 1,2-diol monotosylate derivatives bearing an unsaturated substituent
-
We have succeeded in the easy preparation of optically active 1,2-diol monotosylates bearing an unsaturated substituent via enzymatic hydrolysis. Lipase PS quickly catalyzes the hydrolyses of 2-acetoxybut-3-enyl tosylate, which has a double bond, and 2-acetoxybut-3-ynyl tosylate, which has a triple bond, with excellent enantioselectivity to afford the corresponding optically active compounds. The reaction is also applicable to acetates with a longer chain, which has a double bond at the terminus. To demonstrate the applicability of this method, enantiomerically pure (R)-massoialactone, a natural coconut flavor, has been synthesized from racemic 2-acetoxypent-4-enyl tosylate in several steps. Furthermore, the enzyme can recognize the stereochemistry of olefins, and the (Z)-alkenyl structure is more suitable for the enantioselective hydrolysis than the (E)-isomer.
- Matsumoto,Oohana,Hashimoto,Usuda,Shimoda,Ohshima,Suzuki,Togawa
-
supporting information
p. 3981 - 3988
(2018/06/15)
-
- Formal [5+3] Cycloaddition of Zwitterionic Allylpalladium Intermediates with Azomethine Imines for Construction of N,O-Containing Eight-Membered Heterocycles
-
A formal [5+3] cycloaddition of zwitterionic allylpalladium intermediates with 1,3-dipoles is developed, providing N,O-containing eight-membered heterocyclic compounds in high yields. Catalytically generated zwitterionic allylpalladium intermediates in situ from vinylethylene carbonates or vinyloxiranes acted as dipolarophile. (Figure presented.).
- Yuan, Chunhao,Wu, Yang,Wang, Dongqi,Zhang, Zhenhua,Wang, Chang,Zhou, Leijie,Zhang, Cheng,Song, Baoan,Guo, Hongchao
-
supporting information
p. 652 - 658
(2017/12/26)
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- METHOD FOR PRODUCING ALLYL ALCOHOLS
-
PROBLEM TO BE SOLVED: To provide a method for producing allyl alcohols by direct addition of water to a raw material olefin which can achieve both high selectivity of compounds and high yield. SOLUTION: In a method for producing allyl alcohols by direct addition of water to a raw material olefin, the raw material olefin and water are brought into contact with a solid catalyst, where a catalytically active component containing at least one transition metal element selected from groups 8-10 of the periodic table is carried on an oxide carrier, in the presence of oxygen to convert the raw material olefin to allyl alcohols. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPO&INPIT
- -
-
Paragraph 0078
(2017/05/27)
-
- Versatile PdTe/C catalyst for liquid-phase oxidations of 1,3-butadiene
-
A commercial Pd catalyst based on Sibunit carbon support was treated with H6TeO6 in a reducing media to obtain a Te coating on the surface of Pd particles. The PdTe/C catalyst prepared in this way showed the ability to control the radical chain oxidation of 1,3-butadiene by promoting the selective formation of 2-butene-1,4-diol, 4-hydroxybut-2-enal and furan in DMA (total selectivity of 61% and yield of 7%). At the same time, the catalyst induced oxidation of 1,3-butadiene by a non-radical heterolytic mechanism involving the formation of two groups of primary products: (1) crotonaldehyde and methyl vinyl ketone and (2) the products of oxygenation at the 1,4-positions. The compounds of the second group including 1,4-dimethoxy-2-butene and maleic acid dimethyl ester were formed on PdTe centers in MeOH. Increasing the Te concentration in the PdTe/C catalyst forced the conversion of 1,3-butadiene toward 1,4-oxygenation and simultaneously decreased the intensity of secondary oxidation, resulting in the selective formation of derivatives of the 1,4-oxygenation - 1,4-dimethoxy-2-butene and allenic alcohol methyl ether (total selectivity of 84% and yield of 48%).
- Kuznetsova,Zudin,Kuznetsova,Zaikovskii,Kajitani,Utsunomiya,Takahashi
-
-
- Chirality induction and chiron approaches to enantioselective total synthesis of α-lipoic acid
-
Abstract An efficient, short and convenient asymmetric synthesis of (R)-(+)-lipoic acid in seven steps from chiral hydroxy aldehyde with 32.5% overall yield is described. Synthesis of S and R enantiomers of α-lipoic acid from cis-1,4-butene diol derived chiral lactone is reported with 34 % overall yield. The present synthesis involves use of simple reaction conditions making it a convenient synthesis.
- Chavan, Subhash P.,Pawar, Kailash P.,Praveen, Ch.,Patil, Niteen B.
-
supporting information
p. 4213 - 4218
(2015/06/02)
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- Transfer hydrogenation of organic formates and cyclic carbonates: An alternative route to methanol from carbon dioxide
-
Transfer hydrogenation of organic formates and cyclic carbonates was achieved for the first time using a readily available ruthenium catalyst. Nontoxic and economical 2-propanol was used, both as a solvent and hydrogen source, without the need of using flammable H2 gas under high pressure. This method provides an indirect strategy to produce methanol from carbon dioxide under mild conditions as well as an operationally simple and environmentally benign way to reduce formates and carbonates.
- Kim, Seung Hyo,Hong, Soon Hyeok
-
p. 3630 - 3636
(2015/02/19)
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- 1,3-Dimethylimidazolium-2-carboxylate: A zwitterionic salt for the efficient synthesis of vicinal diols from cyclic carbonates
-
The development of efficient, cheap and recyclable catalysts for reactions under mild reaction conditions is a very attractive topic in green chemistry. Herein, a series of basic ionic liquids (ILs) were investigated as catalysts for the synthesis of vicinal diols via the hydrolysis of cyclic carbonates in order to improve this kind of synthetic process. The effects of the IL structure, the molar ratio of cyclic carbonate to water, and various reaction parameters on the catalytic performance were investigated in detail. It was found that 1,3-dimethylimidazolium-2-carboxylate, a simple halogen-free zwitterionic catalyst, showed high activity (a space-time yield of 1086 h-1) and excellent selectivity for the preparation of ethylene glycol via the hydrolysis of ethylene carbonate. The catalyst could be reused over six times without obvious loss of catalytic activity. Also, it was applicable to a variety of cyclic carbonates for the production of their corresponding vicinal diols with high yields and selectivities. A possible catalytic cycle for this kind of catalytic process was proposed based on the experimental results, NMR spectroscopy and theoretical calculations. This reaction protocol opens a new possibility for chemical synthesis as a substitution for traditional base or basic ILs. This journal is the Partner Organisations 2014.
- Sun, Jian,Yao, Xiaoqian,Cheng, Weiguo,Zhang, Suojiang
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p. 3297 - 3304
(2014/06/10)
-
- 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)
-
- Asymmetric total synthesis of (2S,3S)-3-hydroxypipecolic acid
-
A synthetic route to (2S,3S)-3-hydroxypipecolic acid was achieved from readily available nonchiral pool starting material cis-2-butene-1,4-diol and involved Claisen orthoester rearrangement, Sharpless asymmetric dihydroxylation and intramolecular lactamisation of azido lactone as the key steps.
- Chavan, Subhash P.,Dumare, Nilesh B.,Harale, Kishor R.,Kalkote, Uttam R.
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scheme or table
p. 404 - 406
(2011/02/28)
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- Preparation of 2,3,4-trihydroxybutylarsonic acid: A starting compound for novel arsonolipids
-
Possible routes for the preparation of 2,3,4-trihydroxybutylarsonic acid, a key compound for the synthesis of novel arsonolipids, were experimentally evaluated. The best substrate was found to be 3,4-epoxybutane-1,2-diol. Its reaction with alkaline sodium arsenite, "Na3AsO3," gave the arsonic acid in 50% yield, as two pairs of diastereoisomers, each pair being a racemic mixture. Copyright Taylor & Francis Group, LLC.
- Lala, Maria A.,Tsivgoulis, Gerasimos M.,Ioannou, Panayiotis V.
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p. 2747 - 2760
(2008/12/22)
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- METHOD FOR PRODUCING 2-HYDROXY-4-(METHYLTHIO)BUTANOIC ACID
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A method for producing 2-hydroxy-4-(methylthio)butyric acid which comprises the following steps (A), (B) and (C): Step (A): step of reacting 1,2-epoxy-3-butene with water to obtain 3-butene-1,2-diol, Step (B): step of reacting 3-butene-1,2-diol with methanethiol to obtain 4-(methylthio)butane-1,2-diol, Step (C): step of oxidizing 4-(methylthio)butane-1,2-diol to obtain 2-hydroxy-4-(methylthio)butyric acid.
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-
-
- METHOD FOR PRODUCING UNSATURATED VICINAL DIOL COMPOUND
-
A method for producing an unsaturated vicinal diol compound represented by the formula (2): wherein R1, R2, R3 R4, R5 and R6 are the same or different and each independently represent a hydrogen atom; a C1-C20 alkyl group which may be substituted with a halogen atom or atoms, a C1-C6 alkoxy group or groups, a C2-C7 alkoxycabonyl group or groups, a C6-C10 aryl group or groups, or a carboxyl group or groups; or a C6-C10 aryl group which may be substituted with a halogen atom or atoms, a C1-C6 alkoxy group or groups, a C6-C10 aryl group or groups, or a carboxyl group or groups, which comprises reacting an unsaturated epoxy compound represented by the formula (1): wherein R1, R2, R3, R4, R5 and R6 are the same as defined above, with water in the presence of a silicate containing at least one element selected from a group 5 element and a group 6 element of the long periodic table as a constituent.
- -
-
Page/Page column 7; 8
(2008/06/13)
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- 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)
-
- Effect of a proximal oxygen substituent on the efficacy of ruthenium-catalyzed cross-metathesis and RCM
-
Ruthenium-catalyzed cross-metathesis of various derivatives of 1,2-dihydroxy-3-butene reveals that cyclic acetals are best suited as substrates compared to acyclic diethers or diacetates, while RCM is relatively insensitive to the presence of allylic or homoallylic hydroxy or acetoxy groups.
- Maishal, Tarun K,Sinha-Mahapatra, Dilip K,Paranjape, Kavita,Sarkar, Amitabha
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p. 2263 - 2267
(2007/10/03)
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- Isomerization of allylic silyl ethers catalyzed by ReO3(OSiR3) complexes
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Efficient isomerization of allylic alcohols and allylic ethers at room temperature by rhenium (VII) oxo complexes is described. (C) 2000 Elsevier Science Ltd.
- Bellemin-Laponnaz, Stéphane,Le Ny, Jean Pierre,Osborn, John A.
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p. 1549 - 1552
(2007/10/03)
-
- New synthesis of sn-1,2- and sn-2,3-O-diacylglycerols application to the synthesis of enantiopure phosphonates analogous to triglycerides: A new class of inhibitors of lipases
-
Phosphonate compounds mimic the first transition state occurring during enzymatic carboxyester hydrolysis of natural substrates by forming a covalent bond with the catalytic serine. However, until now the organophosphorus compounds used in the inhibition studies more or less resembled a natural triglyceride substrate. In order to elucidate the interfacial activation and the mechanism of action of lipases, specific inhibitors need to be prepared. To achieve this goal, enantiomerically pure sn-1,2- and sn-2,3O- didecanoylglycerol compounds were prepared - starting from a C-4 chiral synthon, 3-buten-1,2-diol - and treated with n-pentylphosphonic dichloride and p-nitrophenol to afford the corresponding diastereomeric phosphonates, which were acylglycerol analogs. Subsequent separation of each of the phosphonate diastereomers A/B or ent-A/ent-B, performed by HPLC, led to four enantiopure stereoisomers that will be investigated as inhibitors of Human Pancreatic Lipase (HPL) and Human Gastric Lipase (HGL) using the monomolecular film technique.
- Marguet, Frank,Cavalier, Jean-Francois,Verger, Robert,Buono, Gerard
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p. 1671 - 1678
(2007/10/03)
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- Isomerization of vinyl glycols to unsaturated diols
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This invention relates to a process for the isomerization of a vinyl glycol to an unsaturated diol in the presence of a rhenium-based catalyst; and to a catalyst for said isomerization. More specifically, this invention relates to the isomerization of 3-butene-1,2-diol to 2-butene-1,4-diol; and to a process for the manufacture of 1,4-butanediol involving the step of isomerizing 3-butene-1,2-diol to 2-butene-1,4-diol in the presence of said catalyst. The catalyst is characterized in that it comprises a transition metal on a carrier wherein the carrier is a zeolite Y type substance containing silicon and aluminum in a mole ratio of from about 1.5:1 to about 1000:1, and the transition metal is rhenium or a rhenium compound and mixtures thereof present in an amount of from about 0.1 to about 50 weight percent based on total combined weight of the carrier and of the rhenium or rhenium compound and mixtures thereof.
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-
-
- Iodide assisted zeolite catalysed 1,4-addition of water to butadiene monoxide
-
Selective 1,4-addition of water to butadiene monoxide can be achieved in a liquid phase catalytic process using ultrastable Y zeolite as Broensted acid, potassium iodide, and an ether solvent. The reaction mechanism could be elucidated based on the occurrence of intermediate reaction products. Iodide is added to the terminal unsaturated carbon atom of a protonated butadiene monoxide molecule. The strong solvent effect observed can be rationalised based on the nucleophilicity of the iodide depending on the basicity of the ether function. With USY zeolite, the 2-butene-1,4-diol selectivity reaches 73.9% at 100% conversion when using 1,2-dimethoxyethane solvent, 2,5-dihydrofuran being the main by-product. With this catalytic system followed by an additional hydrogenation step, butadiene monoxide can be selectively converted into 1,4-butanediol.
- Remans, Thomas J.,Van Oeffelen, Domien,Steijns, Matt,Martens, Johan A.,Jacobs, Pierre A.
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p. 312 - 315
(2007/10/03)
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- In vitro and in vivo mutagenicity of the butadiene metabolites butadiene diolepoxide, butadiene monoepoxide and diepoxybutane
-
Three metabolites of 1,3-butadiene, namely butadiene diolepoxide, butadiene monoepoxide and diepoxybutane, were tested in the bacterial mutation assay using Salmonella typhimurium Strain TA100 with and without metabolic activation (S9 mix). All three compounds showed a mutagenic response. The bifunctional epoxide was more effective than the diolepoxide which was more effective than the monoepoxide. Toxicity appeared to follow the ranking of the chemicals for their mutagenic potency. The monoepoxide and the diolepoxide were also tested for induction of micronuclei in mouse bone marrow erythrocytes and for dominant lethal mutation induction in postmeiotic male mouse germ cells. The effects of the diepoxide in both in vivo tests have been published earlier. In the micronucleus assay, the three metabolites gave a positive response whereby the diepoxide was more effective than the monoepoxide which was more effective than the diolepoxide. In contrast to the diepoxide which was positive at a dose as low as 36 mg/kg, the monoepoxide and the diol did not show an induction of dominant lethal effects up to doses of 120 and 240 mg/kg, respectively. It is concluded that the metabolites were mutagenic in bacteria without metabolic activation and clastogenic in mouse bone marrow; only the bifunctional diepoxide, however, was active in postmeiotic male mouse germ cells.
- Adler,Kliesch,Nylund,Peltonen
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p. 339 - 345
(2007/10/03)
-
- Synthesis of 1,2,3,4-diepoxybutane from 1,3-butadiene monoxide
-
The possibility of producing 1,2,3,4-diepoxybutane by the epoxidation of 1,3-butadiene monoxide with tert-butylhydroperoxide has been demonstrated. The factors complicating the production and isolation of the target product have been studied. As an alternative to 1,2,3,4-diepoxybutane, the synthesis of 1,2,4,5-diepoxypentane is proposed.
- Mel'nik,Nozhnin,Grechina,Kryukov,Yegorova,Danilova
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p. 455 - 459
(2007/10/03)
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- Synthetic route to optically-pure metabolites of butadiene, and their chiral GC separation
-
The four possible stereoisomers of 3,4-epoxybutane-1,2-diol were stereospecifically synthesized in excellent yields, and fully characterized, as part of a study on the stereochemical aspects of butadiene metabolism and toxicity. GC methodology was developed whereby baseline separation of the enantiomeric pairs was achieved.
- Claffey, David J.,Ruth, James A.
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p. 7929 - 7932
(2007/10/03)
-
- Diastereoselective Reactions of δ-Siloxyallylzirconium Reagents with Aldehydes
-
δ-Siloxyallylzirconium reagent (2) was produced by reaction of the TBDMS protected derivative (6) with zirconocene butene complex "Cp2Zr".Treatment of the δ-siloxyallylzirconium reagent (2) with various aldehydes provided predominantly anti-homoallylic alcohols.
- Clark, Andrew J.,Kasujee, Ismail,Peacock, Joanne L.
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p. 7137 - 7140
(2007/10/02)
-
- Method for purification of alcohols
-
A method for the purification of alcohols from organic soluble impurities has been discovered comprising treating the crude alcohol with a cyclic anhydride followed by an aqueous base and extracting the corresponding half-ester into aqueous solution leaving the impurities in organic solution. This method is particularly useful for the separation of chiral, nonracemic alcohols from the corresponding antipodal ester (the mixture resulting from an enzymatic kinetic resolution) because the separation is non-chromatographic and the enantiomeric integrity of the products is maintained.
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-
- Formal Synthesis of a Unsaturated Trihydroxy C-18 Fatty Acid
-
Stereoselective synthesis of (4R,5S)-2,2-dimethyl-5--1,3-dioxolane-4-carboxaldehyde, a key intermediate for the synthesis of (9S, 12S, 13S)-trihydroxy-(10E, 15Z)-octadecadienoic acid starting from cis-butene-1,4-diol, is described.
- Sharma, Pradeep Kumar
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p. 1825 - 1826
(2007/10/02)
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- An Expedient Approach to (2R,3S)-3-Azido-1,2-epoxy-4-phenylbutane: A key intermediate for HIV protease Inhibitors
-
A facile synthesis of the title product (1) starting from cis-butene-1,4-diol (2) has been described.The isomerised 3-butene-1,2-diol derivative 3 on Sharpless kinetic resolution with (+)-DIPT as a chiral auxiliary provided the enantiomerically pure epoxyalcohol (4).Successive opening of the epoxide (5) with PhMgBr, replacement of OH group with azide and derivatisation of the oxirane ring provided the requisite product 1.
- Gurjar, Makund K.,Devi, N. Rama
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p. 755 - 758
(2007/10/02)
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- Alcohol-ester sparation by reaction with acetate
-
A process is disclosed for the isolation of an enantiomerically enriched alcohol from a first mixture of an enantiomerically enriched 1-arylsulfonate-2 -hydroxy-3-butene and an enantiomerically enriched 1 -arylsulfonate- 2-acyloxy-3-butene. The process includes the steps of: (a) contacting the mixture with a reagent capable of reacting with said 1-arylsulfonate-2-hydroxy-3-butene to remove the arylsulfonate group and produce a mixture of dihydroxybutene monoesters thereby forming a second mixture containing said dihydroxybutene monoesters and unreacted enantiomerically enriched 1-arylsulfonate-2-acyloxy-3-butene (b) contacting the second mixture with reagents capable of hydrolyzing all of the acyl groups in said mixture to hydroxy groups so as to produce a third mixture comprising 1,2-dihydroxy-3-butenes and enantiomerically enriched 1-arylsulfonate-2-hydroxy-3 -butene; (c) washing said third mixture with water so as to remove said 1,2-dihydroxy-3-butenes.
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- HYDRATION OF 1,3-BUTADIENE MONOXIDE
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1-Butene-3,4-diol is obtained as a result of the hydration of 1,3-butadiene monoxide.The highest yields are obtained with sulfuric acid as catalyst.It was shown that the hydration of 1,3-butadiene monoxide over the investigated range of temperatures and acid concentrations is described satisfactorily by a first-order kinetic equation.The reaction obeys the Hammett relationships for acid catalysis.A reaction mechanism is proposed.
- Petrov, V. A.,Zakharova, O. A.,Kryukov, S. I.
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p. 847 - 849
(2007/10/02)
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- Vinyl Epoxide Hydrolysis Reactions
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The rates of hydrolysis of cyclopentadiene oxide (3), cyclohexadiene oxide (4), cycloheptadiene oxide (5), cyclooctadiene oxide (6), butadiene oxide (7), and styrene oxide (8) have been determined as a function of pH.Each epoxide exhibited acid-catalyzed hydrolysis at low pH, and 3-5 showed significant rates for "spontaneous" reaction with solvent at intermediate pH values.The hydrolyses of several of the vinyl epoxides (4 and 5) showed kinetic terms in HO- at pH > ca. 13.Specific chloride effects attributed to nucleophilic addition of Cl- to neutral epoxide were observed for those compounds (3, 4, and 8) hydrolyzed in KCl solutions.From kinetic and product studies, mechanisms for hydrolyses of the vinyl epoxides are postulated.Acid-catalyzed hydrolyses of 3, 4, 5, and 6 were found to be A-1 in nature, proceeding via intermediate allyl cations.Product distributions depended on the structure of the cation.Mechanisms and product distributions for the spontaneous hydrolyses of vinyl epoxides were found to be variable, and dependent on the structure of the epoxide.
- Ross, Angela M.,Pohl, Terese M.,Piazza, Kathryn,Thomas, Michael,Fox, Bonnie,Whalen, Dale L.
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p. 1658 - 1665
(2007/10/02)
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