- Assembly of tunable supramolecular organometallic catalysts with cyclodextrins
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Methylated-β-CDs were used to activate a catalyst by ligand solution trapping, to form second-sphere coordination by ligand complexation, and to increase the regioselectivity of biphasic and homogeneous hydroformylation reactions. Different methylation degrees of the β-CD allow assembly of hydrophobic or hydrophilic catalysts that can be employed in homogeneous or biphasic hydroformylation reactions.
- Leclercq, Loic,Schmitzer, Andreea R.
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Read Online
- 3-Hydroxypropionaldehyde (3-HPA) quantification by HPLC using a synthetic acrolein-free 3-hydroxypropionaldehyde system as analytical standard
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HPLC-based quantification of 3-HPA using a synthetic acrolein-free 3-HPA standard obtained from commercially available 1,2,4-butanetriol through a straightforward and easy synthetic process has advantages over previous colorimetric methods of easier and safer implementation, and greater specificity. This HPLC method is very simple to implement in a lab, does not need any extra handling of the sample to be analyzed, and is suitable even in the presence of other aldehydes and 3-HPA derivatives, provided that the latter do not have similar retention times.
- Burgé,Flourat,Pollet,Spinnler,Allais
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Read Online
- Three-component reductive alkylation of 2-hydroxy-1,4-naphthoquinones with lactols
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Lactols II, obtained by DIBAL reduction of their corresponding lactones I, in equilibrium with their hydroxyaldehyde tautomers III were used in a three-component reductive alkylation with 2-hydroxy-1,4-naphthoquinone to give a series of 3-alkylated 2-hydroxy-1,4-naphthoquinone derivatives IV.
- Kim, Eliana E.,Onyango, Evans O.,Pace, Jennifer R.,Abbot, Timothy M.,Fu, Liangfeng,Gribble, Gordon W.
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Read Online
- Catalytic Oxidation of Tetrahydrofuran in the Presence of Transition Metal Complexes under Aerobic Conditions
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Upon stirring a THF solution of a transition metal under an aerobic atmosphere, γ-butyrolactone and a small amount of lactol and 4-hydroxybutyraldehyde are formed; the turnover number of this catalytic oxidation process can reach 150 when lrCl(CO)(PPh3)2 is used.
- Shi, Min
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Read Online
- Intramolecular oxygen radical additions to α,β-unsaturated esters. Diastereoselective tandem cyclofunctionalization and hydrogen transfer reactions
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The efficiency of a tandem process featuring an oxy radical cyclization and hydrogen transfer reaction of the resultant carbon-based radical has been demonstrated. This methodology affords 2,3-trans-disubstituted tetrahydrofurans by creating two new contiguous stereogenic centers with high levels of 1,2-induction in each step.
- Guindon, Yvan,Denis, Real C.
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Read Online
- Synthesis of (E)-α-hydroxyethyl-α,β-unsaturated aldehydes by the reaction of tetrahydrofuran and aromatic aldehydes
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Although α-functionalized α,β-unsaturated aldehydes have important applications in biomedicine, there are few reports on their synthesis. In this article, a new domino reaction for the synthesis of (E)-α-hydroxyethyl-α,β-unsaturated aldehydes was introduced, in which tetrahydrofuran (THF) used as carbonyl block. The first step is an oxidation of THF to 2-hydroxytetrahydrofuran (HTHF) and then it was condensed with ethanolamine under acid catalysis to obtain imine intermediate, which was further isomerized to enamines and used as nucleophiles to attack aldehydes. This is a simple and efficient way for the preparation of (E)-α-hydroxyethyl-α,β-unsaturated aldehydes with notable advantages of a simple procedure, widespread availability of the substrates.
- Shi, Yong-Sen,Liu, Jian-Feng,Wu, Xiao-Lan,Ke, De-Hong,Xu, Sheng
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supporting information
(2021/08/13)
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- Tweaking the acid-sensitivity of transiently thermoresponsive Polyacrylamides with cyclic acetal repeating units
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Merging the characteristics of thermoresponsive and stimuli-degradable polymers yields so-called transiently thermoresponsive polymers, which can find application for the design of injectable gels, nanoparticles, etc. within a biomedical context. Among these polymers, only a limited number is reported which shows selective degradation under mild acidic conditions. However, extension of the library of transiently thermoresponsive polymers is desired to broadening the biomaterials toolbox to suit specific needs. Three monomers were developed by modification of 2-hydroxyethylacrylamide (HEAm) via tetrahydropyranylation or -furanylation with 3,4-dihydro-2H-pyran (DHP), 2,3-dihydrofuran (DHF) or 2,3-dihydro-5-methylfuran (MeDHF). The presence of an acetal or ketal bond provided the monomers a pH-dependent hydrolysis behavior ranging from minutes to days. RAFT polymerisation allowed for the construction of homopolymers with temperature responsive behavior and pH-dependent hydrolysis which was strongly influenced by nature of the monomeric repeating units.
- De Geest, Bruno G.,Van Herck, Simon
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- Catalytic Selective Oxidation of Primary and Secondary Alcohols Using Nonheme [Iron(III)(Pyridine-Containing Ligand)] Complexes
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The selective oxidation of different primary and secondary alcohols to carbonyl compounds by hydrogen peroxide was found to be catalyzed in conversion ranging from good to excellent by an iron(III) complex of a pyridine-containing macrocyclic ligand (Pc-L), without the need of any additive. The choice of the counteranion (Cl, Br, OTf) appeared to be of fundamental importance and the best results in terms of selectivity (up to 99 %) and conversion (up to 98 %) were obtained using the well-characterized [Fe(III)(Br)2(Pc-L)]Br complex, 4c. Magnetic moments in solid-state, also confirmed in solution ([D6]DMSO) by Evans NMR method, were calculated and point out to an iron metal center in the high spin state of 5/2. The crystal structure shows that the iron(III) center is coordinated by the four nitrogen atoms of the macrocycle and two bromide anions to form a distorted octahedral coordination environment. The catalytic oxidation of benzyl alcohol in acetonitrile was found occurring with better conversions and selectivities than in other solvents. The reaction proved to be quite general, tolerating aromatic and aliphatic alcohols, although very low yields were obtained for terminal aliphatic alcohols. Preliminary mechanistic studies are in agreement with a catalytic cycle promoted by a high-spin iron complex.
- Caselli, Alessandro,Gallo, Emma,Panza, Nicola,Rizzato, Silvia,Tseberlidis, Giorgio,di Biase, Armando
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supporting information
p. 6635 - 6644
(2020/10/30)
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- PRODUCING BDO VIA HYDROFORMYLATION OF ALLYL ALCOHOL MADE FROM GLYCERIN
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A method including hydroformylating, with syngas, allyl alcohol in an allyl alcohol feed, to produce a hydroformylation product comprising 4-hydroxybutyraldehyde and 3-hydroxy-2-methylpropionaldehyde; and producing a 1,4-butanediol (BDO) product comprising BDO and 1,3-methylpropanediol via hydrogenation of at least a portion of the hydroformylation product. A method including hydroformylating, with syngas, allyl alcohol in a feed comprising bio-allyl alcohol, to produce a hydroformylation product comprising 4-hydroxybutyraldehyde and 3-hydroxy-2-methylpropionaldehyde; and producing a BDO product comprising BDO and 1,3-methylpropanediol via hydrogenation of at least a portion of the hydroformylation product. A method including hydroformylating, with syngas, bio-allyl alcohol in a feed comprising bio-allyl alcohol, to produce a hydroformylation product comprising 4-hydroxybutyraldehyde and 3-hydroxy-2-methylpropionaldehyde; producing a BDO product comprising BDO and 1,3-methylpropanediol via hydrogenation of at least a portion of the hydroformylation product; and removing a byproduct of the production of the bio-allyl alcohol prior to hydroformylating the bio-allyl alcohol and/or from the BDO-product.
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Paragraph 0050
(2019/09/06)
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- Preparation method for 4-oxobutyl acetate
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The invention relates to a preparation method for 4-oxobutyl acetate. The method comprises the following steps: a, adding 2,3-dihydrofuran, water, acetic acid and a solid acid catalyst into an organicsolvent under the protection of an inert gas, performing heating, performing stirring for a reaction, and after the reaction is completed, performing filtration; and b, performing reduced-pressure distillation on the filtrate obtained in the step a to obtain the 4-oxobutyl acetate. According to the method provided by the invention, raw materials are cheap and environmentally friendly, two steps of reactions in the reaction process are performed at the same time, an intermediate does not need to be separated, the process is simple, and the method is convenient to operate.
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Paragraph 0019
(2018/07/30)
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- Six-step synthesis of Leonurine and toxicity study on zebrafish
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Leonurine (1), an important ingredient in leonurus sibiricus L., can be used for some gynecological disease. We have developed a concise and efficient synthetic route of Leonurine, which can be optimized for mass production. Commercially available compound 6 and 2,3-dihydrofuran (7) were used as starting materials. And the toxicity study on zebrafish shows that Leonurine would promote the hatching of zebrafish embryos at low concentration and result in acute death or chronic lethal toxicity at high concentration.
- Zhao, Hui,Hu, Xiang-Guo,Xu, Min-Jie,Cai, Qun-Xing,Liu, Yu-Jun,Su, Duo-Meng,Chen, Shi-Jin,Wang, Kai,Gong, Zhu-Nan
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p. 1172 - 1175
(2017/06/19)
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- OLEFIN HYDROFORMYLATION METHODS FOR OBTAINING BRANCHED ALDEHYDES
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The present technology relates to methods of hydroformylating allyl alcohol to 4- hydroxybutanal and 2-memyl-3-hydroxypropanal, comprising (i) admixing allyl alcohol with CO and H2 to form a starting material mixture, and (ii) reacting the starting material mixture in the presence of a catalyst under conditions capable of forming a product mixture comprising 4- hydroxybutanal and 2-methyl-3-hydroxypropanal, wherein the catalyst is a transition metal complex comprising a transition metal ion and a diphosphine ligand with a bite angle from, about 70° to about 100°, and wherein the ratio of 4-hydroxybutanal to 2-methyl-3-hydroxypropanal in the product mixture is less than 1.5: 1.
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Paragraph 0061
(2017/05/20)
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- Backbone-Modified Bisdiazaphospholanes for Regioselective Rhodium-Catalyzed Hydroformylation of Alkenes
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A series of tetraaryl bisdiazaphospholane (BDP) ligands were prepared varying the phosphine bridge, backbone, and substituents in the 2- and 5-positions of the diazaphospholane ring. The parent acylhydrazine backbone was transformed to an alkylhydrazine via a borane reduction procedure. These reduced ligands contained an all sp3 hybridized ring mimicking the all sp3 phospholane of (R,R)-Ph-BPE, a highly selective ligand in asymmetric hydroformylation. The reduced bisdiazaphospholane (red-BDP) ligands were shown crystallographically to have an increased C-N-N-C torsion angle - this puckering resembles the structure of (R,R)-Ph-BPE and has a dramatic influence on regioselectivity in rhodium catalyzed hydroformylation. The red-BDPs demonstrated up to a 5-fold increase in selectivity for the branched aldehyde compared to the acylhydrazine parent ligands. This work demonstrates a facile procedure for increased branched selectivity from the highly active and accessible class of BDP ligands in hydroformylation.
- Wildt, Julia,Brezny, Anna C.,Landis, Clark R.
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p. 3142 - 3151
(2017/09/05)
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- Synthesis of (4: E,6 Z,10 Z)-hexadeca-4,6,10-trien-1-ol and (4 E,6 E,10 Z)-hexadeca-4,6,10-trien-1-ol, the pheromone components of cocoa pod borer moth Conopomorpha cramerella
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A concise and efficient synthesis of the pheromone components of the cocoa pod borer moth, namely (4E,6Z,10Z)-hexadeca-4,6,10-trien-1-ol and (4E,6E,10Z)-hexadeca-4,6,10-trien-1-ol, starting from commercially available materials, was reported. The overall yield was 30.4% and 27.4%, respectively. The stereoselective formation of (E,Z)- or (E,E)-conjugated double bond relied on Sonogashira coupling with (E)-5-bromopent-4-en-1-ol prepared from (E)-5-bromopent-4-enal and the stereoselective hydrogenation of the enyne, while the 10Z-double bond was formed by Wittig reaction from 4-hydroxybutanal and n-hexyltriphenylphosphonium bromide.
- Huang, Fei,Zhang, Yushun,Yao, Yun,Yang, Wanqiu,Tao, Yunhai
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p. 35575 - 35580
(2017/07/28)
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- Methods and Materials for the Production of Monomers for Nylon-4/Polyester Production
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This document describes biochemical pathways for producing 4-hydroxybutyrate, 4-aminobutyrate, putrescine or 1,4-butanediol by forming one or two terminal functional groups, comprised of amine or hydroxyl group, in a C5 backbone substrate such as 2-oxoglutarate or L-glutamate.
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Paragraph 0166
(2016/08/29)
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- MICROORGANISMS AND METHODS FOR PRODUCTION OF 4-HYDROXYBUTYRATE, 1,4-BUTANEDIOL AND RELATED COMPOUNDS
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The invention provides non-naturally occurring microbial organisms having a 4-hydroxybutyrate, 1,4-butanediol, or other product pathway and being capable of producing 4-hydroxybutyrate, 1,4-butanediol, or other product, wherein the microbial organism comprises one or more genetic modifications. The invention additionally provides methods of producing 4-hydroxybutyrate, 1,4-butanediol, or other product or related products using the microbial organisms.
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Page/Page column
(2015/06/03)
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- Iron(II) catalysis in oxidation of hydrocarbons with ozone in acetonitrile
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Oxidation of alcohols, ethers, and sulfoxides by ozone in acetonitrile is catalyzed by submillimolar concentrations of Fe(CH3CN)62+. The catalyst provides both rate acceleration and greater selectivity toward the less oxidized products. For example, Fe(CH3CN)62+-catalyzed oxidation of benzyl alcohol yields benzaldehyde almost exclusively (>95%), whereas the uncatalyzed reaction generates a 1:1 mixture of benzaldehyde and benzoic acid. Similarly, aliphatic alcohols are oxidized to aldehydes/ketones, cyclobutanol to cyclobutanone, and diethyl ether to a 1:1 mixture of ethanol and acetaldehyde. The kinetics of oxidation of alcohols and diethyl ether are first-order in [Fe(CH3CN)62+] and [O3] and independent of [substrate] at concentrations greater than ~5 mM. In this regime, the rate constant for all of the alcohols is approximately the same, kcat = (8 ± 1) × 104 M-1 s-1, and that for (C2H5)2O is (5 ± 0.5) × 104 M-1 s-1. In the absence of substrate, Fe(CH3CN)62+ reacts with O3 with kFe = (9.3 ± 0.3) × 104 M-1 s-1. The similarity between the rate constants kFe and kcat strongly argues for Fe(CH3CN)62+/O3 reaction as rate-determining in catalytic oxidation. The active oxidant produced in Fe(CH3CN)62+/O3 reaction is suggested to be an Fe(IV) species in analogy with a related intermediate in aqueous solutions. This assignment is supported by the similarity in kinetic isotope effects and relative reactivities of the two species toward substrates.
- Bataineh, Hajem,Pestovsky, Oleg,Bakac, Andreja
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p. 1629 - 1637
(2015/03/14)
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- Mechanism of Alcohol Oxidation by FeV(O) at Room Temperature
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Selective oxidation of alcohol to its corresponding carbonyl compound is an important chemical process in biological as well as industrial reactions. The heme containing enzyme CytP450 has been known to selectively oxidize alcohols to their corresponding carbonyl compounds. The mechanism of this reaction, which involves high-valent FeIV(O)-porphyrin?+ intermediate with alcohol, has been well-studied extensively both with the native enzyme and with model complexes. In this paper, we report for the first time the mechanistic insight of alcohol oxidation with FeV(O) complex of biuret TAML (bTAML), which is isoelectronic with FeIV(O)-porphyrin?+ intermediate form in CytP450. The oxidations displayed saturation kinetics, which allowed us to determine both the binding constants and first-order rate constants for the reaction. The K and k values observed for the oxidation of benzyl alcohol by FeV(O) at room temperature (K = 300 M-1, k = 0.35 s-1) is very similar to that obtained by CytP450 compound I at -50 °C (K = 214 M-1, k = 0.48 s-1). Thermodynamic parameters determined from van't Hoff's plot (ΔH~ -4 kcal/mol) suggest hydrogen bonding interaction between substrate and bTAML ligand framework of the FeV(O) complex. Analysis of H/D KIE (kH/kD ~ 19 at 303 K), Hammett correlation and linearity in Bell-Evans-Polyanski plot points to the C-H abstraction as the rate determination step. Finally, experiments using FeV(O18) for benzyl alcohol oxidation and use of the "radical clock" cyclobutanol as a substrate shows the absence of a rebound mechanism as is observed for CytP450. Instead, an ET/PT process is proposed after C-H abstraction leading to formation of the aldehyde, similar to what has been proposed for the heme and nonheme model compounds.
- Ghosh, Munmun,Nikhil,Dhar, Basab B.,Sen Gupta, Sayam
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p. 11792 - 11798
(2015/12/30)
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- Raney Ni-Si catalysts for selective hydrogenation of highly concentrated 2-butyne-1,4-diol to 2-butene-1,4-diol
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Raney Ni-Si catalysts were synthesized by treating Raney Ni with silane in a fluidized bed reactor and tested in the selective hydrogenation of 2-butyne-1,4-diol (BYD) at high concentration. Structural characterizations including XRD patterns, TEM images, and X-ray photoelectron spectroscopy show that Raney Ni-Si catalysts are composed of a Ni core surrounded by nickel silicides. These species transform from Ni-rich silicide (Ni2Si) to Si-rich silicide (NiSi2) with increasing silicification temperature from 250 °C to 450 °C. The insertion of Si atoms into Raney Ni catalysts decreased the catalytic activity, but significantly improved the selectivity to 2-butene-1,4-diol (BED). The beneficial effect of Si on the selectivity hydrogenation of BYD may be caused by the presence of Si at Ni-defect sites, and the formation of the surface nickel silicide that suppress the further hydrogenation of BED. Compared with the traditional Lindlar-type catalysts, such Raney Ni-Si materials can be used extensively in organic synthesis for selective hydrogenation of alkynes, avoiding the associated hazards of toxic additives.
- Chen, Xiao,Zhang, Mingming,Yang, Kaixuan,Williams, Christopher T.,Liang, Changhai
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p. 1118 - 1126
(2014/07/21)
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- RATE AND SELECTIVITY IMPROVEMENT IN HYDROFORMYLATION OF ALLYL ALCOHOL
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A process for producing 4-hydroxybutyraldehyde comprises reacting allyl alcohol with CO/H2 in a reactor in the presence of a catalyst system comprising rhodium complex and trans- 1, 2- bis[bis(3, 5-di-n-alkylphenyl)phosphino]- cyclobutane at a pressure of about 50 psi or lower.
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Paragraph 0019
(2014/01/07)
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- Perspectives on the kinetics of diol oxidation over supported platinum catalysts in aqueous solution
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The catalytic oxidation of a variety of terminal alcohols was performed over Pt/C with 10 bar dioxygen at 343 K in aqueous solvent at low pH. The influences of Pt particle size, carbon support, alcohol structure, and start-up conditions were explored. Although the turnover frequency was not affected by particle size or the carbon support, the structure of the alcohols affected their initial rate of conversion. Both the rate of oxidation of α,ω-diols and selectivity of the diols to the diacids increased with increasing carbon chain length. The rate of 1,6-hexanediol oxidation was independent of dioxygen pressure and the order of reaction with respect to diol concentration depended on the start-up conditions. A kinetic model involving two types of metal sites was proposed to account for the experimental observations.
- Ide, Matthew S.,Davis, Robert J.
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- Characterization of a new enzyme oxidizing ω-amino group of aminocarboxyric acid, aminoalcohols and amines from Phialemonium sp. AIU 274
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A new enzyme exhibiting oxidase activity for ω-aminocarboxylic acids, ω-aminoalcohols, monoamines and diamines was found from a newly isolated fungal strain, Phialemonium sp. AIU 274. The enzyme also oxidized aromatic amines, but not l- and d-amino acids. The Vmax/Km value for hexylamine was higher than those for 6-aminoalcohol and 6-aminhexanoic acid in the aliphatic C6 substrates. In the aliphatic amines, the higher Vmax/Km values were obtained by the longer carbon chain amines. Thus, the enzyme catalyzed oxidative deamination of the ω-amino group in a wide variety of the ω-amino compounds and preferred medium- and long-chain substrates. The oxidase with such broad substrate specificity was first reported here. The enzyme contained copper, and the enzyme activity was strongly inhibited by isoniazid, iproniazid and semicarbazide, but not by clorgyline and pargyline. The enzyme was composed of two identical subunits of 75 kDa.
- Isobe, Kimiyasu,Sasaki, Tomoko,Aigami, Yuusuke,Yamada, Miwa,Kishino, Shigenobu,Ogawa, Jun
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- Liquid-phase catalytic hydrogenation of 2-butyne-1,4-diol to 1,4-butanediol at atmospheric pressure on suspended catalysts
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The optimum parameters of hydrogenation of 2-butyne-1,4-diol to 1,4-butanediol on the suspended palladium and Ni-Raney catalysts at atmospheric pressure were found. In selected conditions a yield up to 90% of 1,4-butanediol was reached.
- Pyatnitsyna,El'Chaninov
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p. 394 - 397
(2013/06/27)
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- NOVEL HYDROFORMYLATION PROCESS
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The present invention relates to a process for producing 4-hydroxybutyraldchyde, characterized in that allyl alcohol dissolved in polar solvents is reacted with CO and H2 in the presence of a catalytic system which is formed from a rhodium complex and a cyclobutane ligand which contains at least two trans-coordinated 1,3-dialkylphenyl- phosphinomethyl groups, with the exclusion of catalysts which contain an aliphatic, araliphatic or cycloaliphatic phosphine as ligand. In which R1 is alkyl, preferably methyl, ethyl or propyl R2 is H or an alkoxy group, R3 and R4 independently of one another, are H, CH2OR1, CH2O-aralkyl, CH2OH, CH2-[P(3,5-R1,R1-4-R2-phenyl)2] or CH2O-(CH2-CH2-O)m-H where m is a number from 1 to 1000.
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Page/Page column 5
(2013/02/28)
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- 2-Butoxyethanol and benzyl alcohol reactions with the nitrate radical: Rate coefficients and gas-phase products
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The bimolecular rate coefficients k NO 3 ? + 2-butoxyethanol and k NO 3 ? + benzyl alcohol were measured using the relative rate technique at (297 ± 3) K and 1 atmosphere total pressure. Values of (2.7 ± 0.7) and (4.0 ± 1.0) × 10-15 cm3/s
- Harrison, Joel C.,Wells
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p. 778 - 788
(2013/01/15)
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- LIGANDS AND CATALYST SYSTEMS FOR HYDROFORMYLATION PROCESSES
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The present invention relates to ligands and catalyst systems for the hydroformylation of short and long chain olefins, preferably for the hydroformylation of ally alcohol producing 4-hydroxybutyraldehyde. The ligands disclosed herein are all-trans phosphinomethyl-cyclobutane ligands, such as, for example, all-trans- 1,2,3, 4-tetra[bis-(3, 5-xylyl)phosphinomethyl]-cyclobutane. The catalyst systems comprise these all-trans phosphinomethyl-cyclobutane ligands in combination with an organometallic rhodium complex such as, e.g., (acctylacetonato)-dicarbonyl-rhodium (I). The ligands and catalyst systems of the present invention may be employed in the hydroformylation of olefins, in particular in the hydroformylation of allylalcohol, and provide improved selectivity and high reaction yields. wherein R1 is alkyl, preferably methyl, ethyl or propyl, R2 is H or an alkoxy group, R3 and R4, independently of one another, CH2OR1, CH2O-aralkyl, CH2OH,CH2-[P(3,5-R1,R1-4-R2-phenyl)2] or CH2O-(CH2-CH2-O)m-H (with m being an integer between 1 and 1.000).
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Page/Page column 6-7
(2013/02/28)
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- A continuous kilogram-scale process for the manufacture of 7-ethyltryptophol
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An expeditious and multikilogram-scale process for the synthesis of 7-ethyltryptophol via a continuous flow reactor from 2-ethylphenylhydrazine and 4-hydroxybutyraldehyde in higher and high yield was described. The main steps in this synthesis involved not only the generation of the hydrazone intermediate in situ but also the catalysis of the subsequent [3 + 3] sigmatropic rearrangement in the tandem loop reactor. Decomposition of the intermediate hydrazone was found to be a key factor resulting in low yield.
- Lv, Yanwen,Yu, Zhiqun,Su, Weike
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supporting information
p. 471 - 475
(2013/01/10)
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- Kinetics and mechanism of the oxidation of diols by butyltriphenylphosphonium dichromate
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The oxidation of four vicinal, four non-vicinal diols and one of their monoethers by butyltriphenylphosphonium dichromate (BTPPD), in dimethylsulfoxide (DMSO), resulted in the formation of corresponding hydroxyaldehyde as a main product of the oxidation. The reactions are of first order with respect to BTPPD, however, second order dependence is obtained with respect to each the diol and hydrogen ion. The oxidation of [1,1,2,2-2H 4]ethanediol exhibited primary kinetic isotope effect (k H/kD = 6.61 at 298 K). The temperature dependence of the kinetic isotope effect suggested the symmetrical transition state in the rate-determining step. The rate constants of oxidation of four vicinal diols show excellent correlation with Taft's ∑ σ* values with negative reaction constant, ρz.ast;. The rate of oxidation of ethanediol has been determined in nineteen different solvents. An analysis of the solvent effect indicates the importance of the cation-solvating power of the solvents. A suitable mechanism has been postulated involving the formation of chromate ester in a pre-equilibrium.
- Panday, Dinesh,Kothari, Seema
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experimental part
p. 918 - 925
(2011/09/19)
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- Oxidation of some vicinal and non-vicinal diols by tetrakis(pyridine)silver dichromate: A kinetic and mechanistic study
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The kinetics of oxidation of four vicinal, four non-vicinal diols and two of their monoethers by tetrakis(pyridine)-silver dichromate (TPSD) have been studied in dimethylsulphoxide (DMSO). The main product of oxidation is the corresponding hydroxycarbonyl compound. The reaction is first order in TPSD. Michaelis-Menten type of kinetics is observed with respect to the diols. The reaction is catalysed by hydrogen ions. The hydrogen ion dependence has the form : kobs = a + b (H+]. The oxidation of [1,1,2,2- 2H4] ethanediol exhibits a substantial primary kinetic isotope effect (kH/kD = 5.91 at 298 K). The reaction has been studied in nineteen different organic solvents and the solvent effect has been analysed using Taft's and Swain's multiparametric equations. The temperature dependence of the kinetic isotope effect indicates the presence of a symmetrical transition state in the rate-determining step. A suitable mechanism has been proposed.
- Meena,Daiya,Sharma,Banerji,Kotai,Sharma, Vinita
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experimental part
p. 1887 - 1893
(2012/04/04)
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- Oxidation of some vicinal and non-vicinal diols by morpholinium chlorochromate: A kinetic and mechanistic study
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The kinetics of oxidation of four vicinal, four non-vicinal diols and two of their monoethers by morpholinium chlorochromate (MCC) have been studied in dimethylsulphoxide (DMSO). The main product of oxidation is the corresponding hydroxycarbonyl compound. The reaction is first order in MCC and the diols. The reaction is catalysed by hydrogen ions. The hydrogen ion dependence is taking the form : kobs = a + b [H+]. The oxidation of [1,1,2,2-2H4]ethanediol exhibits a substantial primary kinetic isotope effect (kH/kD = 5.82 at 298 K). The reaction has been studied in nineteen different organic solvents and the solvent effect has been analysed using Taft's and Swain's multiparametric equations. The temperature dependence of the kinetic isotope effect indicates the presence of a symmetrical transition state in the rate-determining step. A suitable mechanism has been proposed.
- Barthora,Baghmar,Agarwal,Sharma, Vinita
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experimental part
p. 677 - 683
(2012/04/10)
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- Inhibition of 1,4-butanediol metabolism in human liver in vitro
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The conversion of 1,4-butanediol (1,4-BD) to gamma-hydroxybutyric acid (GHB), a drug of abuse, is most probably catalyzed by alcohol dehydrogenase, and potentially by aldehyde dehydrogenase. The purpose of this study was to investigate the degradation of 1,4-BD in cytosolic supernatant of human liver in vitro, and to verify involvement of the suggested enzymes by means of gas chromatography-mass spectrometry. The coingestion of 1,4-BD and ethanol (EtOH) might cause complex pharmacokinetic interactions in humans. Therefore, the effect of EtOH on 1,4-BD metabolism by human liver was examined in vitro. Additionally, the influence of acetaldehyde (AL), which might inhibit the second step of 1,4-BD degradation, was investigated. In case of a 1,4-BD intoxication, the alcohol dehydrogenase inhibitor fomepizole (4-methylpyrazole, FOM) has been discussed as an antidote preventing the formation of the central nervous system depressing GHB. Besides FOM, we tested pyrazole, disulfiram, and cimetidine as possible inhibitors of the formation of GHB from 1,4-BD catalyzed by human liver enzymes in vitro. The conversion of 1,4-BD to GHB was inhibited competitively by EtOH with an apparent K i of 0.56 mM. Therefore, the coingestion of 1,4-BD and EtOH might increase the concentrations and the effects of 1,4-BD itself. By contrast AL accelerated the formation of GHB. All antidotes showed the ability to inhibit the formation of GHB. In comparison FOM showed the highest inhibitory effectiveness. Furthermore, the results confirm strong involvement of ADH in 1,4-BD metabolism by human liver.
- Lenz, Daniel,Juebner, Martin,Bender, Katja,Wintermeyer, Annette,Beike, Justus,Rothschild, Markus A.,Kaeferstein, Herbert
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scheme or table
p. 647 - 654
(2012/06/01)
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- Oxidation of butane-1,3-, butane-1,4-, 2-methyl pentane-2,4- and 3-methyl pentane-2,4-diols by cerium(IV) in aqueous acidic medium catalyzed by rhodium(III)
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The oxidation kinetics of butane-1,3-diol, butane-1,4-diol, 2-methyl pentane-2,4-diol and 3-methyl pentane-2,4-diol with cerium(IV) catalyzed by rhodium(III) in aqueous sulfuric acid showed a peculiar nature with respect to the variation in oxidant concentration, such that the reaction follows first-order kinetics in [Ce(IV)] at low [Ce(IV)] and then reaches a maximum with increasing [Ce(IV)], beyond which further increase in the oxidant concentration retards the rate. The rate shows direct proportionality with respect to [diol] at low concentrations, becoming independent of [diol] at higher concentrations. The rate is first order in catalyst. Retarding effects are observed when [H +] and [Ce(III)] are increased, while [Cl-] and hence ionic strength have a positive effect on the rate. Spectroscopic studies confirmed that the primary hydroxyl groups in butane-1,3-diol and butane-1,4-diol resulted in the formation of 3-hydroxy butanal and 4-hydroxy butanal, respectively. In the case of oxidation of the secondary hydroxyl groups in 2-methyl pentane-2,4-diol and 3-methyl pentane-2,4-diol, the products of oxidation were 4-hydroxy-4-methyl pentan-2-one and 4-hydroxy-3-methyl pentan-2-one, respectively.
- Tandon, Praveen K.,Khanam, Shaista Z.,Yadav, Suresh C.,Shukla, Ritesh C.
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scheme or table
p. 739 - 746
(2012/07/01)
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- Enantioselective hydroformylation of N-vinyl carboxamides, allyl carbamates, and allyl ethers using chiral diazaphospholane ligands
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Rhodium complexes of diazaphospholane ligands catalyze the asymmetric hydroformylation of N-vinyl carboxamides, allyl ethers, and allyl carbamates; products include 1,2- and 1,3-aminoaldehydes and 1,3-alkoxyaldehydes. Using glass pressure bottles, short reaction times (generally less than 6 h), and low catalyst loading (commonly 0.5 mol %), 20 substrates are successfully converted to chiral aldehydes with useful regioselectivity and high enantioselectivity (up to 99% ee). Chiral Roche aldehyde is obtained with 97% ee from the hydroformylation of allyl silyl ethers. Commonly difficult substrates such as 1,1- and 1,2-disubstituted alkenes undergo effective hydroformylation with 89-97% ee and complete conversion for six examples. Palladium-catalyzed aerobic oxidative amination of allyl benzyl ether followed by enantioselective hydroformylation yields the β3-aminoaldehyde with 74% ee.
- McDonald, Richard I.,Wong, Gene W.,Neupane, Ram P.,Stahl, Shannon S.,Landis, Clark R.
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supporting information; experimental part
p. 14027 - 14029
(2011/01/04)
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- Hydroformylation process
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A catalyst, useful for the hydroformylation of allyl alcohol, is described. The catalyst comprises a rhodium complex and a 6-bis(3,5-dialkylphenyl)phosphino-N-pivaloyl-2-aminopyridine or a 3-bis(3,5-dialkylphenyl)phosphino-2H-isoquinolin-1-one. The invention also includes a process for the production of 4-hydroxybutyraldehyde comprising reacting allyl alcohol with a mixture of carbon monoxide and hydrogen in the presence of a solvent and the catalyst. The process gives a high ratio of the linear product 4-hydroxybutyraldehyde to the branched co-product 3-hydroxy-2-methylpropionaldehyde.
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Page/Page column 7-8
(2010/09/09)
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- Motualevic acids and analogs: Synthesis and antimicrobial structure-activity relationships
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Synthesis of the marine natural products motualevic acids A, E, and analogs in which modifications have been made to the ω-brominated lipid (E)-14,14-dibromotetra-deca-2,13-dienoic acid or amino acid unit are reported, together with antimicrobial activities against Staphylococcus aureus, methicillin-resistant S. aureus, Enterococcus faecium, and vancomycin-resistant Enterococcus.
- Cheruku, Pradeep,Keffer, Jessica L.,Dogo-Isonagie, Cajetan,Bewley, Carole A.
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scheme or table
p. 4108 - 4111
(2010/08/20)
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- Hydroformylation process
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A process for the production of 4-hydroxybutyraldehyde is described. The process comprises reacting allyl alcohol with a mixture of carbon monoxide and hydrogen in the presence of a solvent and a catalyst system comprising a rhodium complex and a substituted or unsubstituted 4,5-bis(di-n-alkylphosphino)xanthene. The process gives high yield of 4-hydroxybutyraldehyde compared to 3-hydroxy-2-methylpropionaldehyde.
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Page/Page column 5
(2009/11/30)
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- Hydroformylation process
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A process for the production of 4-hydroxybutyraldehyde is described. The process comprises reacting allyl alcohol with a mixture of carbon monoxide and hydrogen in the presence of a solvent and a catalyst system comprising a rhodium complex and a trans-1,2-bis(bis(3,5-di-n-alkylphenyl)phosphinomethyl)-cyclobutane. The process gives high yield of 4-hydroxybutyraldehyde compared to 3-hydroxy-2-methylpropionaldehyde.
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Page/Page column 5-6
(2008/06/13)
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- Hydroformylation process
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A process for the production of 4-hydroxybutyraldehyde is described. The process comprises reacting allyl alcohol with a mixture of carbon monoxide and hydrogen in the presence of a solvent and a catalyst system comprising a rhodium complex and a 2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis[bis(3,5-di-n-alkylphenyl)phosphino]butane. The process gives high yield of 4-hydroxybutyraldehyde compared to 3-hydroxy-2-methylpropionaldehyde.
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Page/Page column 5-6
(2008/06/13)
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- Catalytic hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol at atmospheric pressure in the liquid phase
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Selective hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol on suspended palladium and Raney nickel catalysts at atmospheric pressure was studied. The optimal parameters of this reaction were determined. Samples containing 90% 2-butene-1,4-diol were
- Pyatnitsyna,El'chaninov,Savost'yanov
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- Kinetics of oxidation of 1,4-butylene glycol by dihydroxydiperiodatoargentate(III) in alkaline medium
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Kinetics of oxidation of 1,4-butylene glycol by dihydroxydiperiodatoargentate(III) in alkaline liquid has been investigated by spectrophotometry in the 298.2-318.2K range. The order in oxidant was pseudo first order and the order with respect to 1,4-butylene glycol was 1apt/dt = {kK1K2[OH- ][HOCH2CH 2CH2CH2OH]2[Ag(III)] t}/{[H2IO43-] + K 1[OH-] + K1K2[OH-] [HOCH2CH2CH2CH2OH]} = k obs [Ag(III)]t. A plausible mechanism involving a pre-equilibrium of adduct formation between the complex and reductant was proposed. The activation parameters along with rate constants of the rate-determining step were calculated.
- Shan, Jin-Huan,Li, Sheng-Min,Huo, Shu-Ying,Zhao, Wen-Jie,Shen, Shi-Gang,Sun, Han-Wen
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p. 424 - 425
(2007/10/03)
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- Hydroformylation
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The present invention relates to a process for hydroformylating in the presence of a catalyst comprising at least one complex of a metal of transition group VIII with mono-phosphorus compounds which are capable of dimerizing via noncovalent bonds as ligands, to such catalysts and to their use.
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- Kinetics and mechanism of oxidation of some vicinal and non-vicinal diols by quinolinium bromochromate
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Kinetics of oxidation of four vicinal, four non-vicinal diols and two of their monoethers by quinolinium bromochromate (QBC) have been studied in dimethyl sulphoxide (DMSO). The main product of oxidation is the corresponding hydroxycarbonyl compound. The reaction is first order each in QBC and the diols. The reaction is catalysed by hydrogen ions. The hydrogen ion dependence is taking the form: kobs = a + b[H+]. The oxidation of [1,1,2,2-2H4] ethanediol exhibits a substantial primary kinetic isotope effect (kH/kD = 5.83 at 298 K). The reaction has been studied in nineteen different organic solvents and the solvent effect has been analysed using Taft's and Swain's multiparametric equations. The temperature dependence of the kinetic isotope effect indicates the presence of a symmetrical transition state in the rate-determining step. A suitable mechanism has been proposed.
- Vyas, Shweta,Sharma, Pradeep K.
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p. 1219 - 1223
(2007/10/03)
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- Catalytic oxidation of tetrahydrofuran in the presence of 14-membered hexaaza macrocyclic Copper (II) complexes with hydrogenperoxide
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Copper (II) Complexes of the 14-membered hexaaza-macrocycles; 1, 8-dimethyl-; 1, 8-diethyl-; 1, 8-dipropyl-; 1, 8-dibutyliso-; 1, 8-dibutylsec- and 1, 8-dibenzyl- 1, 3, 6, 8, 10, 13-hexaazacyclotetra decane ([Cu{R2[14]aneN6}](ClO 4)2) catalysed efficiently the selective oxidation of tetrahydroforan into the corresponding τ-butyrolactone and a small amount of tetrahydrofuran-2-ol and 4-hydroxybutyraldehyde, using dil. H 2O2 as the oxidant. The conversion of this catalytic oxidation process can reach 98.6% when [Cu{(Benzyl)2 [14] ane N 6}](ClO4)2 is used.
- Salavati-Niasari,Najafian
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p. 538 - 539
(2007/10/03)
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- Method for producing 1,4-butanediol
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A process for preparing 1,4-butanediol and, if desired, gamma-butyrolactone and THF by oxidizing butane or benzene to form a product stream including maleic anhydride, absorbing maleic anhydride from the product stream with a high-boiling inert solvent in an absorption stage to give a liquid absorption product, esterifying the liquid absorption product with a C1-C5 esterifying alcohol in an esterification stage to form an esterification product comprising the corresponding diester and high-boiling inert solvent, then hydrogenating the esterification product to give a hydrogenation product which comprises the products of value, 1,4-butanediol and, if desired, gamma-butyrolactone and tetrahydrofuran and the esterifying alcohol and which is separated by distillation into the products of value and the esterifying alcohol, and recycling the esterifying alcohol to the esterification zone, which comprises separating the esterification product into the diester and the inert solvent by distillation under reduced pressure prior to the hydrogenation, recycling the inert solvent to the absorption stage, and hydrogenating the diester in the liquid phase over a fixed-bed catalyst.
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Page column 7
(2008/06/13)
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- Chemoselective oxidation of primary alcohols to aldehydes with Gluconobacter oxydans
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The production of aliphatic and aromatic aldehydes by oxidation of primary alcohols was achieved with Gluconobacter oxydans DSM 2343. The biotransformation was optimised studying the oxidation of 2-phenyl-1-ethanol to 2-phenylacetaldehyde. A high molar conversion (95% chromatographic conversion, 83% of isolated yield) was obtained using cells grown on glycerol as the main carbon source and directly used in the cultural medium after 24 h at 28°C, pH 4.5 and 5 g L-1 substrate concentration. The conversion of structurally different primary alcohols was performed under these conditions allowing the chemoselective production of aldehydes, sometimes with very good yields.
- Villa, Raffaella,Romano, Andrea,Gandolfi, Raffaella,Sinisterra Gago, José V.,Molinari, Francesco
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p. 6059 - 6061
(2007/10/03)
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- Kinetics and mechanism of oxidation of some diols by benzyltrimethylammonium chlorobromate
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Kinetics of oxidation of five vicinal, four non-vicinal diols, and one of their monoethers by benzyltrimethylammonium chlorobromate (BTMACB) have been studied. The vicinal diols yield the products arising out of the glycol-bond fission while the other diols afford the hydroxycarbonyl compounds. The reaction is first order with respect to diols and the BTMACB. The reaction failed to induce the polymerization of acrylonitrile. There is no effect of benzyltrimethylammonium chloride or potassium bromide on the reaction rate. The proposed reactive oxidizing species is chlorobromate ion. The effect of solvent composition indicated that the rate increases with an increase in the polarity of the solvent. The oxidation of [1,1,2,2-2H4]ethanediol show an absence of primary kinetic isotope effect. The value of solvent isotope effect, k(H2O)/k(D2O), at 288 K for the oxidation of ethanediol, propane-1,3-diol and 3-methoxybutan-1-ol are 3.32, 1.04 and 1.01 respectively. A cyclic mechanism involving a glycol-bond fission has been proposed for the oxidation of the vicinal diols. The other diols are oxidised by a hydride-transfer mechanism, as are monohydric alcohols.
- Bhatt, Monica,Sharma, Pradeep K.,Banerji, Kalyan K.
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p. 826 - 831
(2007/10/03)
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- One-step convergent synthesis of the steroid ring system via the coupling of gamma,delta-unsaturated Fischer carbene complexes with o-ethynylbenzaldehyde.
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[reaction: see text]. Simultaneous and stereoselective construction of the steroid B and C rings is observed in a tandem process involving the coupling of o-ethynylbenzaldehyde with 2-alkenylcyclopentylcarbene-chromium complexes.
- Ghorai,Herndon,Lam
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p. 3535 - 3538
(2007/10/03)
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- Supported palladium catalysts modified with heteropoly acids in 1,4-butynediol hydrogenation
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Low-percentage palladium catalysts activated with heteropoly acids are proposed for hydrogenation of 1,4-butynediol into 1,4-butanediol.
- Zakarina,Volkova
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- Tautomerism and vapor-phase transformations of 2-hydroxytetrahydrofuran
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The relative stability of 2-hydroxytetrahydrofuran and the tautomeric 4-hydroxybutanal was determined by the semi-empirical AM1 method. It was concluded that the cyclic tautomer predominates in the gas phase at 25°C. Vapor-phase dehydration of 2-hydroxytetrahydrofuran in the presence of porcelain and silica gel L leads to a quantitative yield of 2,3-dihydrofuran.
- Lebedev,Leite,Fleisher,Stonkus
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p. 775 - 778
(2007/10/03)
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- Oxidation of alcohols by [Cp*Rh(ppy)(OH)]+
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Rh(III) polypyridine complexes ([Cp*Rh(ppy)(H2O)]2+; ppy = 2,2′-bipyridine, 2,2′-bipyridine-4,4′-dicarboxylate, o-phenanthroline, tetrahydro-4,4′-dialkyl-bis-oxazole) oxidize in organic or aqueous alkaline solution primary and secondary alcohols to aldehydes or ketones and are thereby reduced to the Rh(I) complexes Cp*Rh(ppy). The Rh(III) form can be regenerated by oxidants like pyruvate or oxygen, making the reaction quasi-catalytic. The reaction follows an autocatalytic pathway; hydrogen transfer from the a-CH2 group of an alcoholate complex [Cp*Rh(ppy)(OR)]+ to Cp*Rh(I)(ppy) is suggested to yield the Rh(II) intermediate Cp*Rh(ppy)H as the key and rate determining step. The knowledge of Rh(III)/Rh(I) redox potentials allows to estimate the thermodynamic driving force of the reaction which is not more than about 300mV.
- Koelle, Ulrich,Fraenzl, Holger
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p. 1321 - 1326
(2007/10/03)
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- A general synthetic route towards γ- and δ-lactones. Total asymmetric synthesis of (-)-muricatacin and the mosquito oviposition pheromone (5R, 6s)- 6-acetoxy-hexadecanolide
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Five (or six) membered asymmetric lactones are synthesized from γ- butyrolactone (or δ-valerolactone) in a straightforward way using the following reaction sequence: reduction, Wittig-Schlosser coupling, Sharpless asymmetric dihydroxylation, oxidation and lactonization. Thus, (-)muricatacin is synthesized in six steps (43% overall yield). Furthermore, (5R,6S)-6- acetoxy-hexadecanolide is prepared in eight steps (38% overall yield) via a carbonate ester, utilizing a novel lactonization with inversion of stereochemistry.
- Couladourosand, Elias A.,Mihou, Anastasia P.
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p. 4861 - 4862
(2007/10/03)
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- Kinetics and mechanism of oxidation of diols by quinolinium fluorochromate
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The kinetics of oxidation of four vicinal diols, four non-vicinal diols and two of their monoethers by quinolinium fluorochromate (QFC) have been studied in dimethylsulphoxide. The main product of oxidation is the corresponding hydroxycarbonyl compound. The reaction is first order in QFC. Michaelis-Menten type kinetics have been observed with respect to the diols. The oxidation of [1,1,2,22H4] ethanediol exhibits a substantial primary kinetic isotope effect (k(H)/k(D) = 6.35 at 303 K). The reaction has been in nineteen different organic solvents and the solvent effect has been analysed using Taft's and Swain's multiparametric equation. The temperature dependence of the kinetic isotope effect indicates the presence of a symmetrical transition state in the rate-determining step. A suitable mechanism has been proposed.
- Choudhary, Kirti,Sharma, Pradeep K.,Banerji, Kalyan K.
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p. 325 - 330
(2007/10/03)
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