- Enantioselective Synthesis of α-Thiocarboxylic Acids by Nitrilase Biocatalysed Dynamic Kinetic Resolution of α-Thionitriles
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The enantioselective synthesis of α-thiocarboxylic acids by biocatalytic dynamic kinetic resolution (DKR) of nitrile precursors exploiting nitrilase enzymes is described. A panel of 35 nitrilase biocatalysts were screened and enzymes Nit27 and Nit34 were found to catalyse the DKR of racemic α-thionitriles under mild conditions, affording the corresponding carboxylic acids with high conversions and good-to-excellent ee. The ammonia produced in situ during the biocatalytic transformation favours the racemization of the nitrile enantiomers and, in turn, the DKR without the need of any external additive base.
- Lauder, Kate,Anselmi, Silvia,Finnigan, James D.,Qi, Yuyin,Charnock, Simon J.,Castagnolo, Daniele
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supporting information
p. 10422 - 10426
(2020/07/24)
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- Synthesis method 2- hydroxyl carboxylic ester (by machine translation)
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The method, is simple 2 - energy consumption, energy consumption is low, the production :(1) of waste water can be greatly reduced, the yield of the target product is high 2 - and the production cost ;(2) is greatly reduced (1). 2 - The method comprises the following steps, preparing 2 - hydroxycarboxylate, with an acid ;(3) by a byproduct ammonium salt (2) in step, and filtering the excess acid, to remove the byproduct ammonium salt, to obtain 2 - hydroxyl carboxylic acid ester product, by esterification reaction in step (, and filtering to remove 2 - the excess, alcohol), from, the reaction, solution obtained by the reaction solution; of the catalyst under the, action of, a catalyst, to obtain the product of the compound. (by machine translation)
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Paragraph 0052; 0053
(2020/05/05)
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- Production system of 2-aminobutanamide
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The utility model provides a production system of 2-aminobutanamide, which comprises a first reactor, a second reactor, a third reactor, a fourth reactor, a fifth reactor and a sixth reactor, the second reactor is communicated with the first reactor and is used for reacting 2-hydroxybutyronitrile with an ammonia source to prepare 2-aminobutyronitrile; the third reactor is communicated with the second reactor and is used for carrying out hydrolysis reaction on the 2-aminobutyronitrile and strong base to prepare the 2-aminobutyramide. The device effectively reduces waste water, waste gas and waste residues, effectively reduces the use amount of hydrogen cyanide, improves the content of target products, and reduces the production cost.
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Paragraph 0069; 0093; 0094; 0107-0113
(2020/04/17)
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- Preparation method and preparation system of 2-aminobutyramide
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The invention provides a preparation method and a preparation system of 2-aminobutyramide. The preparation method comprises: (1) generating 2-hydroxybutyronitrile from hydrogen cyanide and n-propanalunder the action of a first catalyst; (2) adding an ammonia source and a second catalyst to the 2-hydroxybutyronitrile obtained in the step (1), and carrying out a reaction to generate 2-aminobutyronitrile; and (3) removing the excess ammonia from the reaction solution obtained in the step (2), adding a strong base and a third catalyst, and carrying out a hydrolysis reaction to obtain DL-2-aminobutanamide. According to the present invention, with the method and the system, the wastewater, the waste gas and the waste residue can be effectively reduced, the consumption of hydrogen cyanide can beeffectively reduced, the content of the target product can be increased, and the production cost can be reduced.
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Paragraph 0091; 0092-0010
(2019/10/01)
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- Highly chemoselective and efficient Strecker reaction of aldehydes with TMSCN catalyzed by MgI2 etherate under solvent-free conditions
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Strecker reaction of various substituted aromatic aldehydes, heteroaromatic aldehydes, aliphatic aldehydes and α,β-unsaturated aldehydes with trimethylsilyl cyanide (TMSCN) was realized in the presence of 5 mol % of MgI2 etherate in a mild, efficient and highly chemoselective manner under solvent-free conditions.
- He, Kailun,Liu, Huijun,Zhang, Xingxian,Zhou, Jing
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supporting information
p. 933 - 936
(2019/03/08)
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- Preparation method of (S)-(+)-2-aminobutanamide hydrochloride
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The invention discloses a synthetic process of a chiral drug (S)-alpha-ethyl-2-oxo-pyrrolidine acetamide (levetiracetam) intermediate (S)-(+)-2-aminobutanamide hydrochloride which has anti-epileptic function. The synthetic process comprises the following steps: performing condensation on acetone cyanohydrins and n-propanal as initial raw materials in the presence of a catalyst to obtain 2-hydroxybutyronitrile; then carrying out a reaction with ammonia to obtain 2-amino butyronitrile; then carrying out hydrolysis to obtain 2-aminobutanamide; then splitting and salifying the 2-aminobutanamide to obtain a target product. The synthetic process is high in yield, the raw materials are low in price and are easily purchased on a large scale, and the synthetic process overcomes the defects that several existing processes need highly toxic and highly polluting raw materials and is simple in process operation and low in cost. Mother liquor after splitting is further racemized and split and is recycled repeatedly, so that the synthetic process is suitable for industrial production.
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Paragraph 0032; 0033; 0034
(2019/01/23)
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- Stereodivergence in the Ireland-Claisen Rearrangement of α-Alkoxy Esters
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A systematic investigation into the Ireland-Claisen rearrangement of α-alkoxy esters is reported. In all cases, the use of KN(SiMe3)2 in toluene gave rearrangement products corresponding to a Z-enolate intermediate with excellent diastereoselectivity, presumably because of chelation control. On the other hand, chelation-controlled enolate formation could be overcome for most substrates through the use of lithium diisopropylamide (LDA) in tetrahydrofuran (THF).
- Podunavac, Ma?a,Lacharity, Jacob J.,Jones, Kerry E.,Zakarian, Armen
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supporting information
p. 4867 - 4870
(2018/08/24)
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- Fast microwave-assisted resolution of (±)-cyanohydrins promoted by lipase from Candida antarctica
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Enzymatic kinetic resolution (EKR) of (±)-cyanohydrins was performed by using immobilized lipase from Candida antarctica (CALB) under conventional ordinary conditions (orbital shaking) and under microwave radiation (MW). The use of microwave radiation contributed very expressively on the reduction of the reaction time from 24 to 2 h. Most importantly, high selectivity (up to 92percent eep) as well as conversion was achieved under MW radiation (50-56percent).
- Ribeiro, Sandra S.,Ferreira, Irlon M.,Lima, Jo?o P. F.,De Sousa, Bruno A.,Carmona, Rafaela C.,Santos, Alcindo A. Dos,Porto, André L. M.
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p. 1344 - 1350
(2015/07/15)
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- An efficient cyanosilylation of aldehydes with trimethylsilyl cyanide catalysed by MgI2 etherate
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A convenient procedure for the synthesis of cyanohydrins by the addition of trimethylsilyl cyanide to aromatic aldehydes, heteroaromatic aldehydes, aliphatic aldehydes and unsaturated aldehydes catalysed by MgI2 etherate (MgI2(OEt2)n) in good to excellent yields is described.
- Wang, Yanping,Feng, Meiling,Liu, Yingshuai,Zhang, Xingxian
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p. 566 - 567,2
(2020/09/16)
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- PROCESS FOR PRODUCTION OF CYANOHYDRIN COMPOUND, AND PROCESS FOR PRODUCTION OF ALPHA HYDROXYESTER COMPOUND
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A process according to the present invention for producing a cyanohydrin compound is a process for producing a cyanohydrin compound by performing a reaction between a carbonyl compound such as an aldehyde compound and hydrogen cyanide in the presence of a catalyst, a content of the carbonyl compound in a reaction system being not more than 50 mol % with respect to the cyanohydrin compound. Thus provided is a process for producing a cyanohydrin compound in good yield from an aldehyde compound and hydrogen cyanide.
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Page/Page column 6
(2010/10/19)
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- PROCESS FOR PRODUCTION OF CYANOHYDRIN COMPOUND, AND PROCESS FOR PRODUCTION OF ALPHA-HYDROXYESTER COMPOUND
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A process according to the present invention for producing a cyanohydrin compound is a process for producing a cyanohydrin compound by performing a reaction between a carbonyl compound such as an aldehyde compound and hydrogen cyanide in the presence of a catalyst, a content of the carbonyl compound in a reaction system being not more than 50 mol% with respect to the cyanohydrin compound. Thus provided is a process for producing a cyanohydrin compound in good yield from an aldehyde compound and hydrogen cyanide.
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Page/Page column 9
(2010/08/09)
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- PROCESS AND APPARATUS FOR PRODUCTION OF CYANOHYDRIN COMPOUND, AND PROCESS FOR PRODUCTION OF ALPHA -HYDROXYESTER COMPOUND
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A process according to the present invention for producing a cyanohydrin compound flow-reacts a carbonyl compound with hydrogen cyanide in the presence of a catalyst, and can therefore reduce the residence time. This makes it possible to reduce the period of time over which the resulting cyanohydrin compound is exposed to an unreacted portion of the carbonyl compound. As a result, the resulting cyanohydrin compound can be prevented from reacting with the unreacted portion. This makes it possible to produce the cyanohydrin compound in good yield. That is, the process according to the present invention for producing a cyanohydrin compound produces a cyanohydrin compound in good yield from a carbonyl compound and hydrogen cyanide.
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Page/Page column 13-14
(2010/08/09)
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- Chiral solvating agents for cyanohydrins and carboxylic acids
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We have shown that a structure as simple as an ion pair of (R)- or (S)-mandelate and dimethylamminopyridinium ions possesses structural features that are sufficient for NMR enantiodiscrimination of cyanohydrins. Moreover, 1H NMR data of cyanohydrins of known configuration obtained in the presence of the mandelate-dimethylaminopyridinium ion pair point to the existence of a correlation between chemical shifts and absolute configuration of cyanohydrins. Mandelate-DMAPH+ ion pair and mandelonitrile form a 1:1 complex with an association constant of 338 M-1 (ΔG 0, -3.4 kcal/mol) for the (R)-mandelonitrile/(R)-mandelate-DMAPH + and 139 M-1 (ΔG0, -2.9 kcal/mol) for the (R)-mandelonitrile/(S)-mandelate-DMAPH+ complex. To understand the origin of enantiodiscrimination, the geometry optimization and energy minimization of the models of ternary complexes of (S)-mandelonitrile/(R)- mandelate/DMAPH+ and (S)-mandelonitrile/(S)-mandelate/DMAPH + complexes was performed using DFT methodology (B3LYP) with the 6-31+G(d) basis set in Gaussian 3.0. Further, analysis of optimized molecular model obtained from theoretical studies suggested that (i) DMAP may be replaced with other amines, (ii) the hydroxyl group of mandelic acid is not necessary for stabilization of ternary complex and may be replaced with other groups such as methyl, (iii) the ion pair should form a stable ternary complex with any hydrogen-bond donor, provided its OH bond is sufficiently polarized, and (iv) α-H of racemic mandelic acid should also get resolved with optically pure mandelonitrile. These inferences were experimentally verified, which not only validated the proposed model but also led to development of a new chiral solvating agent for determination of ee of carboxylic acids and absolute configuration of aryl but not alkyl carboxylic acids.
- Moon, Lomary S.,Pal, Mohan,Kasetti, Yoganjaneyulu,Bharatam, Prasad V.,Jolly, Ravinder S.
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body text
p. 5487 - 5498
(2010/11/05)
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- Stereospecific α-methallylation of hydroxyaldehydes by silatropic ene cyclisation
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We describe the thermal rearrangement of aldehydes bearing an α-(allyl- or crotylsilyl)oxy substituent. The transformations are best described mechanistically as intramolecular silatropic ene reactions based on stereoselectivity, kinetic and computed transition state data. The overall process constitutes a stereospecific (meth)allylation of α-hydroxyaldehydes, under neutral conditions, in which the hydroxyl protecting group is also the (meth)allylating agent.
- Robertson, Jeremy,Hall, Michael J.,Green, Stuart P.
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experimental part
p. 5541 - 5551
(2009/12/09)
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- Purification and characterization of a novel (R)-hydroxynitrile lyase from Eriobotrya japonica (Loquat)
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A hydroxynitrile lyase was isolated and purified to homogeneity from seeds of Eriobotrya japonica (loquat). The final yield, of 36% with 49-fold purification, was obtained by 30-80% (NH4)2SO4 fractionation and column chromatography on DEAE-Toyopearl and Concanavalin A Sepharose 4B, which suggested the presence of a carbohydrate side chain. The purified enzyme was a monomer with a molecular mass of 72 kDa as determined by gel filtration, and 62.3 kDa as determined by SDS-gel electrophoresis. The N-terminal sequence is reported. The enzyme was a flavoprotein containing FAD as a prosthetic group, and it exhibited a Km of 161 μM and a k cat/Km of 348 s-1 mM-1 for mandelonitrile. The optimum pH and temperature were pH 5.5 and 40°C respectively. The enzyme showed excellent stability with regard to pH and temperature. Metal ions were not required for its activity, while activity was significantly inhibited by CuSO4, HgCl2, AgNO3, FeCl3, β-mercaptoethanol, iodoacetic acid, phenylmethylsulfonylfluoride, and diethylpyrocarbonate. The specificity constant (kcat/Km) of the enzyme was investigated for the first time using various aldehydes as substrates. The enzyme was active toward aromatic and aliphatic aldehydes, and showed a preference for smaller substrates over bulky one.
- Ueatrongchit, Techawaree,Kayo, Ai,Komeda, Hidenobu,Asano, Yasuhisa,H-Kittikun, Aran
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p. 1513 - 1522
(2008/12/21)
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- PROCESS FOR PRODUCTION OF 2-HYDROXY ESTERS
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The invention provides an easy and simple process for the production of 2-hydroxy esters from cyanohydrins, specifically, a process for the production of 2-hydroxy esters represented by the general formula (1) (exclusive of ethyl 2-hydroxy-4-phenylbutyrate), characterized by introducing an acid into a mixture comprising a cyanohydrin represented by the general formula (2), an alcohol, an organic solvent and water: [Chemical formula 1] R1 -CH(OH)-COOR2 (1) R1 -CH(OH)(CN) (2) wherein R1 is hydrogen, a substituted or unsubstituted aliphatic hydrocarbon group which has 1 to 12 carbon atoms and may contain oxygen, sulfur, or nitrogen, a substituted or unsubstituted alicyclic hydrocarbon group which has 3 to 12 carbon atoms and may contain oxygen, sulfur, or nitrogen, or a substituted or unsubstituted aryl or aralkyl group which has 3 to 14 carbon atoms and may contain oxygen, sulfur, or nitrogen; and R2 is alkyl which has 1 to 12 carbon atoms and may contain oxygen, sulfur, or nitrogen.
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Page/Page column 11
(2010/11/30)
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- Nitrile hydratase and a method for producing amides
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An objective of the present invention is to provide a nitrile hydratase capable of producing 2-hydroxy-4-methylthiobutyroamide. The present invention provides a novel nitrile hydratase producing α-hydroxyamide using, α-hydroxnitrile as the substrate, and the encoding DNA thereof. The enzyme can be obtained from Rhodococcus sp. Further, the enzymatic activity of the enzyme can he maintained stably during the reaction. The present invention provides a method for producing amide compounds, the method comprising the step of reacting this enzyme to nitrile compounds. According to the present invention, from hydroxy nitrile compounds, corresponding amide compounds can be produced biochemically without reducing the enzyme activity of nitrile hydratase.
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- Chiral Pt(II)/Pd(II) pincer complexes that show C-H?Cl hydrogen bonding: Synthesis and applications to catalytic asymmetric aldol and silylcyanation reactions
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A chiral C2-symmetric NCN ligand, (5R,7R)-1,3-bis(6,6-dimethyl-5,6,7,8-tetrahydro-5,7-methanoquinolin-2-yl)benzene has been synthesized. A direct cyclometalation of this ligand with K2MCl4 (M = Pt, Pd) in dry acetic acid offered the corresponding pincer complexes, [(5R,7R)-1,3-bis(6,6-dimethyl-5,6,7,8-tetrahydro-5,7-methanoquinolin-2-yl)phenyl]platinum(II) chloride 5a and its palladium(II) analogue 5b. The Pt(II) and Pd(II) complexes 5 were characterized by NMR spectroscopy, and X-ray crystal structure analysis was done for the Pt(II) complex. The NMR data for both the complexes and X-ray crystal structural data for the chloro-Pt(II) complex indicate the existence of intramolecular C-H?Cl hydrogen bonding both in solution and in solid states. Chloride abstraction from 5a by treatment with silver triflate resulted in the corresponding triflate complex 6a, which generates the corresponding cationic aqua complex 7a in the presence of water molecules. The Pt(II) complex 6a/7a was used as asymmetric catalyst in the aldol reaction between methyl isocyanoacetate and aldehydes and also in the silylcyanation of aldehydes.
- Yoon, Myeong Sik,Ramesh, Rengan,Kim, Jeongryul,Ryu, Dowook,Ahn, Kyo Han
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p. 5939 - 5946
(2007/10/03)
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- A new (R)-hydroxynitrile lyase from Prunus mume: Asymmetric synthesis of cyanohydrins
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A new hydroxynitrile lyase (HNL) was isolated from the seed of Japanese apricot (Prunus mume). The enzyme has similar properties with HNL isolated from other Prunus species and is FAD containing enzyme. It accepts a large number of unnatural substrates (benzaldehyde and its variant) for the addition of HCN to produce the corresponding cyanohydrins in excellent optical and chemical yields. A new HPLC based enantioselective assay technique was developed for the enzyme, which promotes the addition of KCN to benzaldehyde in a buffered solution (pH=4.5).
- Nanda, Samik,Kato, Yasuo,Asano, Yasuhisa
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p. 10908 - 10916
(2007/10/03)
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- The CSIC reaction on substrates derived from aldehydes
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The Carbanion-mediated Sulfonate (Sulfonamide) Intramolecular Cyclization reaction (CSIC reaction) on conveniently functionalized cyanoalkylsulfonates and cyanoalkylsulfonamides derived from aldehydes is possible and gives the new heterocyclic ring systems 5-alkyl-4-amino-5H-1,2- oxathiole 2,2-dioxide and 3-alkyl-5H-4-amino-5-cyano-5H-2,3- dihydroisothiazole 1,1-dioxide in good yield. (C) 2000 Elsevier Science Ltd.
- Marco, José L.,Ingate, Simon T.,Jaime, Carlos,Beá, Ivan
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p. 2523 - 2531
(2007/10/03)
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- Deamination Reactions, 54. - Decomposition of 1-Cyano-1-propanediazonium Ions
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The nitrous acid decomposition of 2-aminobutanenitrile (9) was studied with regard to product distribution and stereochemistry.The formation of 2-(hydroxyimino)butanenitriles (21, 22; 8-28percent) indicates the intervention of 1-cyanopropyl radicals (24) that are captured by NO.The polar reactions lead mainly to elimination (10-13) and nucleophilic substitution (14-16), rearrangement playing a minor role. (R)-9 was prepared from (R)-2-aminobutanoic acid.The nitrous acid deamination of (R)-9 afforded the cyanohydrin 16 with 81percent net inversion.Owing to destabilization of the carbocation 26 by CN, the SN2 route of nucleophilic displacement is preferred over SN1.The influence of CN is shown to be smaller than that of CF3. Key Words: α-Cyanodiazonium ions / α-Cyanoalkyl radicals / Carbocations, destabilized / Substitution, nucleophilic / Deamination reactions / Diazonium ions / Radicals
- Bunse, Michael,Kirmse, Wolfgang
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p. 1499 - 1502
(2007/10/02)
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- A General Synthesis of 3,5-Dihalo-2H-1,4-oxazin-2-ones from Cyanohydrins
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In a novel approach starting from O-trimethylsilyl protected or unprotected cyanohydrins and oxalyl chloride or bromide, a series of unknown 6-substituted 3,5-dihalo-2H-1,4-oxazin-2-ones were prepared.The method was shown to be efficient for various types of cyanohydrins; however cyclization was not obtained with cyanohydrins containing bulky substituents, electron-rich aryl or heteroaryl groups.A mechanism is proposed.
- Meerpoel, Lieven,Hoornaert, Georges
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p. 905 - 908
(2007/10/02)
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- SYNTHESIS OF 3,5-DIHALOGENO-2H-1,4-OXAZIN-2-ONES FROM CYANOHYDRINES
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The title compounds 4 were obtained on treatment of cyanohydrines 3 of aliphatic and aryl aldehydes with oxalyl chloride or bromide in chlorobenzene at 90 deg C.Evidence for their structure is given by their spectroscopic data and by the Diels Alder reaction of 4a and 4g with acetylenic dienophiles to yield substituted pyridines.Cycloaddition was also observed with ethene.
- Meerpoel, L.,Hoornaert, G.
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p. 3183 - 3186
(2007/10/02)
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- Exo- and Endohormones. XI. Synthesis of Monounsaturated Sex Pheromones of Lepitoptera via α-Dicetones
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α-Dicetones (5), prepared starting either with cyanohydrines (1) or with N,N-diethyl oxamate (6), were converted via the dihydrazones 11 ito acetylenes (12).Replacement of the protecting group by the acatate group and partial stereoselective reduction of the triple bond led finally to the title conpounds.
- Oprean, I.,Ciupe, Hilke,Gansca, Lucia,Hodosan, F.
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p. 283 - 289
(2007/10/02)
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- Metabolites of the Higher Fungi. Part 19. Serpenone, 3-Methoxy-4-methyl-5-prop-1-enylfuran-2(5H)-one, a new γ-Butyrolactone from the Fungus Hypoxylon serpens (Barrons strain) (Persoon ex Fries)Kickx
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Culture solutions of the fungus Hypoxylon serpens (Barrons strain) contain a new butyrolactone as the major metabolite, which has been identified as 3-methoxy-4-methyl-5-prop-1-enylfuran-2(5H)-one (2),and small quantities of the reduced analogue, 3-methoxy-4-methyl-5-propylfuran-2(5H)-one (3); the structures have been established by synthesis of compound (3).A new rapid synthesis of the isomeric 4-methoxy-3,5-disubstituted analogues is described and the two groups of compounds are compared spectroscopically.
- Anderson, John R.,Edwards, Raymond L.,Whalley, Anthony J. S.
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p. 215 - 222
(2007/10/02)
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