- Fast and Selective Oxidation of Primary Alcohols to Aldehydes or to Carboxylic Acids and of Secondary Alcohols to Ketones Mediated by Oxoammonium Salts under Two-Phase Conditions
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Primary alcohols are quantitatively oxidized to aldehydes in a few minutes at 0 deg C in CH2Cl2-0.35 M aqueous NaOCl in the presence of catalytic amounts of 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (3b).Cocatalysis by Br- and buffering of pH at 8.6 with NaHCO3 are also required.Secondary alcohols are converted to ketones.Further oxidation of aldehydes to carboxylic acids is slow, but the reaction is completed in a few minutes under the same conditions by addition of catalytic amounts of phase-transfer catalyst.All reactions are highly selective.Onlya slight excess of NaOCl is required.The method can be applied to saturated alkyl and aryl alkyl substrates.
- Anelli, Pier Lucio,Biffi, Carlo,Montanari, Fernando,Quici, Silvio
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- Vanadium-catalyzed carboxylation of linear and cyclic C5 and C6 alkanes
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Cyclopentane, cyclohexane, pentane, and hexane are carbonylated in single-pot processes and under mild conditions to carboxylic acids (highest yields of 54-33% and turnover numbers [TONs] of 76-50) by vanadium (IV) and (V) complexes in TFA. These complexes present N,O- or O,O-ligands, namely basic forms of aminoalcohols and of (hydroxyimino)dicarboxylic acids, trifluoroacetate, or triflate. The effects of various parameters (e.g., catalyst type, oxidizing agent, CO pressure, temperature, reaction time, type of solvent) were investigated. The use of either too low or too high CO pressures is discouraged, because the former promote the formation of trifluoroacetate esters and the latter, above a certain level, do not result in higher yields or TONs of the carboxylic acids. Carbon- and oxygen-centered radical mechanisms are suggested by experiments with radical traps and by acid product distribution.
- Reis, Patricia M.,Silva, Jose A.L.,Palavra, Antonio F.,Frausto Da Silva, Joao J.R.,Pombeiro, Armando J.L.
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- Catalytic oxidation of α-alkenes with hydrogen peroxide to carboxylic acids in the presence of peroxopolyoxotungstate complexes
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Fine organic synthesis investigation has been performed, focusing on the possibility of efficient oxidation of α-alkenes by hydrogen peroxide under conditions of phase transfer catalysis using bifunctional metal complex catalysts based on peroxotungsten compounds of general formula Q3{PO4[WO(O2)2]4}, where Q is organic cation containing quaternary nitrogen atom. Catalysts screening has been done at oxidation of octene-1, decene-1 and dodecene-1 by 30% aqueous hydrogen peroxide to obtain carboxylic acids: heptanoic, nonanoic and undecanoic acids being of importance since used as precursors in the synthesis of various organic and biologically active compounds. This approach to the synthesis of carboxylic acids may be of interest for the processes of “green chemistry” occurring under mild conditions (Т??100?°С, Р – atm) in one stage without organic solvents, and providing high target product yields (86–97%).
- Pai,Selivanova,Oleneva,Berdnikova,Beskopyl'nyi
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- An efficient and ultrastable single-Rh-site catalyst on a porous organic polymer for heterogeneous hydrocarboxylation of olefins
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A heterogeneous hydrocarboxylation process of olefins to obtain carboxylic acids with one more carbon was first realized using a single-Rh-site catalyst formed on porous organic polymer (Rh1/POPs). The in situ formation of hydrophilic porous ionic polymer from hydrophobic POPs with the help of CH3I led to high activity and superb stability.
- Yuan, Qiao,Song, Xiangen,Feng, Siquan,Jiang, Miao,Yan, Li,Li, Jingwei,Ding, Yunjie
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- Oxoperoxo molybdenum(VI) and tungsten(VI) and oxodiperoxo molybdate(VI) and tungstate(VI) complexes with 8-quinolinol: Synthesis, structure and catalytic activity
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A solution obtained by dissolving MoO3 in a moderate excess of H2O2 reacts with 8-quinolinol (QOH) to give [MoO(O 2)(QO)2] (1), but, when the same reaction is conducted with a large excess of H2O2, an anionic complex is formed, which reacts with PPh4Cl to give the corresponding salt [MoO(O 2)2(QO)][PPh4] (2 · PPh4). Freshly prepared WO3 behaves the same way and, depending on the amount of H2O2 used, as above, produces either [WO(O 2)(QO)2] (3) or [WO(O2)2(QO)] [PPh4] (4 · PPh4), respectively. Crystallographic analyses reveal the coordination geometries around the metal center in these complexes to be distorted pentagonal bipyramids. These compounds show interesting catalytic properties in the oxidation of alcohols using H 2O2 as the terminal oxidant. In the case of aromatics, including benzylic and cinnamylic alcohols, the oxidation occurs selectively, affording aldehydes or ketones with reasonably high turnover numbers. Taking benzyl alcohol as a representative case, a probable mechanism of the alcohol-to-aldehyde conversion mediated by the prepared catalysts is suggested. The oxidation of aliphatic primary alcohols, under the same conditions, does not show the above selectivity: the reaction yields the corresponding aldehydes as well as carboxylic acids. The work was also extended to study the catalytic activity towards the oxidation of phenol and various sulfides and amines using the same oxidants. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
- Maiti, Swarup K.,Banerjee, Surajit,Mukherjee, Alok K.,Abdul Malik,Bhattacharyya, Ramgopal
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- Organoboranes. 35. Reaction of Alkylthioboronic Esters with Trichloromethyllithium: Preparation of One-Carbon-Extended Carboxylic Acids and Thioacetals from Alkenes via Hydroboration
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Various 2-alkyl-1,3,2-dithiaborolanes, RB(S2C2H4) (1), were converted to the corresponding carboxylic acids, RCO2H (2), by using LiCCl3 in THF, followed by oxidation with alkaline hydrogen peroxide.For R=hexyl, a reaction intermediate is converted by solvent into another compound, C6H13C(S2C2H4)B2 (9a), characterized spectroscopically.The yields of 2 decreased with increasing bulkiness of the alkyl groups R.Although the configuration of R= trans-2-methylcyclopent-1-yl (1k) was retained in the product (>98percent trans), a significant degree of epimerization tookplace for R= exo-norbornyl (1j) during the oxidation (exo : endo = 86 : 14).More uniquely, the intermediates 9 were easily hydrolyzed by heating the reaction mixture with aqueous NaOH to give the corresponding 2-alkyl-1,3-dithiolanes 3.Stereochemical integrity was retained in the products derived from 1j and 1k.Since 1 was prepared by the hydroboration of alkenes, this sequence provides a new method for introducing oxycarbonyl or thioacetal functionality into alkenes in a regioselective manner, and, in the case of 3, also with stereocontrol.
- Brown, Herbert C.,Imai, Toshiro
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- Cationic ruthenium(II) complexes supported on mesoporous silica as catalyst precursors in the selective oxidative cleavage of 1-octene
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The selective oxidative cleavage of 1-octene to heptanal and heptanoic acid is reported. A range of model and silica-immobilized ruthenium(II) systems were evaluated. The MCM-41 and SBA-15 immobilized systems were found to show superior activity when compared to their homogeneous counterparts and were found to exert control over the selective formation of aldehydes or carboxylic acids. This could be achieved by varying the reaction times with very high yields being achieved at relatively short reaction times and low metal concentrations. The immobilized catalysts were characterized using nitrogen sorption, powder X-ray diffraction, transmission and scanning electron microscopies, solid-state NMR spectroscopy and thermogravimetric analysis.
- Kotzé, Hendrik,Mapolie, Selwyn
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- Catalytic activity of cyclophosphazenic polypodands in phase-transfer reactions. Comparison with open-chain analogues
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The catalytic activity of cyclophosphazenic polypodands 1a-c was evaluated in typical reactions performed under solid-liquid (SL) and liquid-liquid (LL) phase-transfer catalysis (PTC) conditions. Such activity is largely determined by the complexation extent of 1a-c which is in turn related to the number of binding sites of the ligand (1a+Y- (Na+>K+2>Rb+ and SCN- I-> Br-). Also the presence of water was found to play an important role. Comparison with open-chainanalogues PEG 2 and TRIDENT 3 showed that polypodands 1a-c due to their excellent stability simplicity of preparation and high complexing ability can be considered promising phase transfer catalysts especially under SL-PTC conditions. Cyclophosphazenic polypodands are efficient catalysts in anion promoted reactions (e.g. nucleophilic substitution, alkylation, reduction, oxidation reactions) under SL and LL-PTC conditions. Catalytic activity is mainly related to their complexation capability.
- Landini, Dario,Maia, Angelamaria,Corda, Luciana,Maccioni, Antonio,Podda, Gianni
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- Catalyst parameters determining activity and selectivity of supported gold nanoparticles for the aerobic oxidation of alcohols: The molecular reaction mechanism
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As previously reported for for solventless reactions, gold nanoparticles supported on ceria are also excellent general heterogeneous catalysts for the aerobic oxidations of alcohols in organic solvents. Among organic solvents it was found that toluene is a convenient one. A systematic study on the influence of the particle size and gold content on the support has established that the activity correlates linearly with the total number of external gold atoms, and with the surface coverage of the support. Amongst catalysts with different supports, but similar gold particle size and content, gold on ceria exhibits the highest activity. By means of a kinetic study (influence of σ+ parameter, kinetic isotopic effect, temperature, alcohol concentration and oxygen pressure) a mechanistic proposal consisting of the formation of metalalcoholate, β-hydride shift from carbon to metal and M-H oxidation has been proposed that explains all experimental results.
- Abad, Alberto,Corma, Avelino,Garcia, Hermenegildo
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- ONE-POT SYNTHESIS OF (Z)-4-ALKENOIC ACIDS
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The reaction of β-propiolactone with di-(Z)-1-alkenylcuprates, prepared from Grignard reagents, copper(I) iodide and acetylene, gave (Z)-4-alkenoic acids in high yields in one-pot operation.
- Fujisawa, Tamotsu,Sato, Toshio,Kawara, Tatsuo,Naruse, Kouichi
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- Thermal stability, decomposition enthalpy, and Raman spectroscopy of 1-alkene secondary ozonides
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The synthesis of a series of 1-alkene secondary ozonides was monitored with Raman spectroscopy which is very effective in the detection of the O-O stretching band of the 1,2,4-trioxolane ring. The 1-alkene secondary ozonides thermal decomposition was studied with DSC (differential scanning calorimetry). For all ozonides studied the decomposition onset was found at about 106 °C and the decomposition peak at about 130 °C. The decomposition enthalpy ΔHdec of the secondary ozonides examined was found in the range of -313 to -347 kJ/mol. Despite the considerable amount of heat evolved, the decomposition was not explosive. The decomposition products of 1-octadecene ozonide were studied by TGA-FTIR (thermogravimetric analysis coupled with FT-infrared spectroscopy) and by GC-MS. The main products detected were formic acid and heptadecanal.
- Cataldo, Franco
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- Novel and catalytic oxidation of internal epoxides to α-diketones
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A catalytic system based on Bi(0)-Cu(OTf)2 is efficient for the selective one-pot oxidation of 1,2-disubstituted epoxides to α-diketones under molecular oxygen and DMSO.
- Antoniotti,Dunach
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- STRUCTURE OF DIPTOCARPILIDINE
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Diptocarpilidine (bp 193-194 deg C (4 mm)) has been isolated from the epigeal part and seeds of Diptychocarpus strictus (Fisch) Trautv., and its structure has been established as 1-cyano-6-methylsulfinylhexane.
- Aripova, S. F.,Abdilalimov, O.,Bagdasarova, E. S.,Aizikov, M. I.,Yunusov, S. Yu.,Kurmukov, A. G.
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- Action d'organolithiens et organomagnesiens sur la propiolactone en presence de sel cuivreux Synthese d'acides carboxyliques
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Organocuprate reagents, as well as Grignard reagents under the catalytic action of copper bromide, react with propiolactone to give the corresponding homologous acid with three more carbon atoms in good yields.
- Normant, J. F.,Alexakis, A.,Cahiez, G.
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- Crown Cation Complex Effects. 10. Potassium tert-Butoxide Mediated Penultimate Oxidative Hydrolysis of Nitriles
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The failure of phase-transfer catalysis to improve either the yield or rapidity of basic nitrile hydrolysis is due, in part, to the poor solubility of quaternary ammonium hydroxides in nonpolar solutions.An alternative hydrolysis method which involves potassium tert-butoxide mediated oxidative cleavage of the nitrile with loss of the cyano carbon is presented.The isolated yields reported here range from 21-93percent and are found to be highest for long-chain aliphatic nitriles such as cyanohexadecane.
- DiBiase, Stephen A.,Wolak, Raymond P.,Dishong, Dennis M.,Gokel, George W.
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- Whole-Cell Photoenzymatic Cascades to Synthesize Long-Chain Aliphatic Amines and Esters from Renewable Fatty Acids
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Long-chain aliphatic amines such as (S,Z)-heptadec-9-en-7-amine and 9-aminoheptadecane were synthesized from ricinoleic acid and oleic acid, respectively, by whole-cell cascade reactions using the combination of an alcohol dehydrogenase (ADH) from Micrococcus luteus, an engineered amine transaminase from Vibrio fluvialis (Vf-ATA), and a photoactivated decarboxylase from Chlorella variabilis NC64A (Cv-FAP) in a one-pot process. In addition, long chain aliphatic esters such as 10-(heptanoyloxy)dec-8-ene and octylnonanoate were prepared from ricinoleic acid and oleic acid, respectively, by using the combination of the ADH, a Baeyer–Villiger monooxygenase variant from Pseudomonas putida KT2440, and the Cv-FAP. The target compounds were produced at rates of up to 37 U g?1 dry cells with conversions up to 90 %. Therefore, this study contributes to the preparation of industrially relevant long-chain aliphatic chiral amines and esters from renewable fatty acid resources.
- Bornscheuer, Uwe T.,Cha, Hee-Jeong,Hollmann, Frank,Hwang, Se-Yeun,Kumar, Akula Ravi,Kwon, Yong-Uk,Lee, Da-Som,Oh, Deok-Kun,Park, Jin-Byung,Schuiten, Eva,Vo?, Moritz
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- Calixarene-Catalyzed Permanganate Oxidation of Organic Compounds
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The calixarene 1 bearing six trioxadecyl groups on the phenolic oxygens served as an effective catalyst for the oxidation of alkenes, alkynes, and alcohols with KMnO4 in CH2Cl2.The reaction of alkenes, alkynes, and primary alcohols gave carboxylic acids in high yields, but that of secondary alcohols gave ketones in high or moderate yields.
- Nomura, Eisaku,Taniguchi, Hisaji,Otsuji, Yoshio
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- Oxidation of primary and secondary alkanols with the CeIII-LiBr- H2O2 system
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Action of a novel oxidation system, Ce(NO3)3? 6H2O (cat.)-LiBr (cat.)-H2O2 (stoichiometric oxidant) on primary aliphatic C6-C9 alcohols gives selectively esters, whereas secondary aliphatic C5-C9 alcohols are converted into ketones. Selectivity of these transformations is provided by slow addition of H2O2 to the other reactants.
- Kapustina,Sokova,Nikishin
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- Effect of Dimethylsulfoxide on Hydrolysis of Lipase
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To establish an industrially feasible reaction process, the effect of dimethylsulfoxide (DMSO) added to an aqueous solution on the hydrolysis of lipase was investigated using fluorescent substrates. Several lipases from microorganisms were improved in their hydrolysis activities against 4-methylumbelliferyl oleate by DMSO. Variation was found in the effect of DMSO depending on the species of lipase. After the high stability of the lipase from Pseudomonas fluorescens in DMSO solution was confirmed, hydrolysis by this lipase of four acyl-4-methylumbelliferones was studied kinetically at different DMSO concentrations. DMSO added to an aqueous solution increased the Vmax of this lipase for a substrate with strong hydrophobicity, and decreased that value for a substrate with an opposite property. On the other hand, DMSO had a very small effect on Km for each substrate. A fluorometric study suggested that DMSO induced a change of the chemical environment that surrounded tryptophan residues of the lipase. Such conformational change would be one of the causes of the DMSO-induced alteration of its reactive property. These results suggest that the addition of DMSO may be a novel method of 'solvent engineering' of this enzyme.
- Tsuzuki, Wakako,Ue, Akemi,Kitamura, Yoshiaki
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- Catalytic activity of baker's yeast in ester hydrolysis
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The hydrolysis of phenyl esters of alkane carboxylic acids in the presence of lyophilized Saccharomyces cerevisiae has been studied. In the case of phenyl acetate the hydrolysis obeyed MichaelisMenten kinetics, behavior typical of esterase-catalyzed reactions. For phenyl laurate our experiments provided evidence for the growth-associated production of lipase by baker's yeast.
- Bialecka-Florjanczyk, Ewa,Krzyczkowska, Jolanta,Stolarzewicz, Izabela
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- Hydrocarboxylation of terminal alkenes in supercritical carbon dioxide
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The catalytic hydrocarboxylation of linear alkenes to carboxylic acids using supercritical carbon dioxide as a solvent was studied. High selectivities in acids have been obtained. The best results were achieved when adding a perfluorinated surfactant to the reaction mixture (93% conversions and ca. 80% selectivity). Comparative multinuclear high-pressure NMR spectroscopic studies in [D8]THF and in supercritical CO2 show the formation of Pd0 species. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Estorach, Clara Tortosa,Orejon, Arantxa,Ruiz, Nuria,Masdeu-Bulto, Anna M.,Laurenczy, Gabor
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- Oxidation of Vicinal Diols to α-Hydroxy Ketones with H2O2 and a Simple Manganese Catalyst
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α-Hydroxy ketones are valuable synthons in organic chemistry. Here we show that oxidation of vic-diols to α-hydroxy ketones with H2O2 can be achieved with an in situ prepared catalyst based on manganese salts and pyridine-2-carboxylic acid. Furthermore the same catalyst is effective in alkene epoxidation, and it is shown that alkene oxidation with the MnII catalyst and H2O2 followed by Lewis acid ring opening of the epoxide and subsequent oxidation of the alkene to α-hydroxy ketones can be achieved under mild (ambient) conditions.
- Mecozzi, Francesco,Dong, Jia Jia,Saisaha, Pattama,Browne, Wesley R.
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- OXIDATION OF ALDEHYDES BY THIAZOLIUM IONS AND FLAVIN IN A CATIONIC MICELLE
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The reactions of aldehydes with thiazolium ions and flavin were investigated in the presence of CTABr micelle.The reactions were found to be facilitated by a cationic micelle.
- Yano, Yumihiko,Hoshino, Yutaka,Tagaki, Waichiro
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- An atom-economic approach to carboxylic acids via Pd-catalyzed direct addition of formic acid to olefins with acetic anhydride as a co-catalyst
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An effective Pd-catalyzed hydrocarboxylation of olefins using formic acid with acetic anhydride as a co-catalyst is described. A variety of carboxylic acids are obtained in good yields with high regioselectivities under mild reaction conditions without the use of toxic CO gas.
- Wang, Yang,Ren, Wenlong,Shi, Yian
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- Tailoring the catalytic activity of metal organic frameworks by tuning the metal center and basic functional sites
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In this study, zirconium, zinc, and copper-based metal organic framework catalysts were synthesized. In order to tune the catalytic activity, the coordinative unsaturated metal-organic frameworks were functionalized with different amines by an economical
- Rani, Poonam,Srivastava, Rajendra
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- Aliphatic aldehyde reductase activity related to the formation of volatile alcohols in vietnamese coriander leaves
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Vietnamese coriander (Persicaria odorata Lour.) belongs to a group known as cilantro mimics with the 'cilantro' flavor, in which C10 and C12 aldehydes and alcohols have been found as the potent odor compounds. Their composition isolated by different extraction methods varied. The enzyme activity was assayed, and the reductase acting on some aliphatic aldehydes with NADH/NADPH as a coenzyme was found in a crude enzymatic system of fresh leaves. The maximum activity was observed at pH 8.0 in Na-phosphate and at pH 8.5 to 9.0 in a glycine-NaOH buffer, using heptanal as a substrate. The activated reductase that caused the alcohol generation to increase after a time was inhibited by p-hydroxymercuribenzoate. Our results, which are the first to be reported on Vietnamese coriander leaves, reveal the presence of aliphatic aldehyde dehydrogenase, which is responsible for acid formation, and elucidate the strong activity of the aliphatic aldehyde reductase.
- Quynh, Cung Thi To,Iijima, Yoko,Morimitsu, Yasujiro,Kubota, Kikue
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- Synthesis of decorated carbon nanotubes with Fe3O4 and Au nanoparticles and their application in catalytic oxidation of alcohols in water
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Magnetic decorated multi-walled carbon nanotubes (m-MWCNTs) were functionalized using 4-aminopyridine to introduce pyridine groups on the carbon nanotubes (mf-MWCNTs). The pyridine functionalized magnetic decorated multi-walled carbon nanotubes were used as a support for gold nanoparticles. A thorough structural characterization has been carried out by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM) images, EDS, CHN and spectroscopy. The mf-MWCNTs supported gold nanoparticles were found to be an efficient catalyst for the oxidation of alcohols in water.
- Kaboudin, Babak,Saghatchi, Fatemeh,Kazemi, Foad
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- Selective Autoxidation of Electron-Rich Substrates under Elevated Oxygen Pressures
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We report here the observation of a novel autoxidation pathway which occurs with electron-rich substrates.Tertiary amines, dialkyl thioethers, olefins, and alkynes under high oxygen pressures (>20 bars of O2), in polar solvents, and at elevated temperatures (>90 deg C) yield in good to excellent selectivity amine oxides, sulfoxides, and site-specific olefin and alkyne cleavage products, respectively.The results of mechanistic studies, including high oxygen pressure electrochemical studies, are discussed.A mechanism for this novel oxygenation reaction pathway that is consistent with the observed results is proposed.It involves an initial unfavorable electron transfer from the electron-rich substrate to oxygen to yield superoxide and the radical cation, which reacts with triplet oxygen to yield the oxygenated radical cation intermediate, a suspected potent oxidant.Electron transfer to the oxygenated radical cation from additional substrate (chain reaction) or superoxide yields a zwitterionic intermediate.This intermediate either reacts with additional substrate (O-atom transfer) to yield product (sulfoxide and N-oxide, in the case of thioethers and tertiary amines) or is converted with unimolecular reactivity to dioxetane-like (in the case of alkenes) or dioxetene-like (in the case alkynes) derived products.
- Correa, Paul E.,Hardy, Gordon,Riley, Dennis P.
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- Oxidation of Aldehydes into Carboxylic Acids with Molecular Oxygen Using Nickel(II) Complex Catalyst
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The oxidation of aldehydes into the corresponding carboxylic acids using a catalytic amount of nickel(II) complex under an oxygen atmosphere at room temperature is described.Bisnickel(II) (Ni(dmp)2) behaves as an excellent catalyst for the oxidation of aldehydes to afford the corresponding carboxylic acids in good yields.
- Yamada, Tohru,Rhode, Oliveriro,Takai, Toshihiro,Mukaiyama, Teruaki
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- Heterogeneously catalysed cleavage of carbon-carbon double bonds with hydrogen peroxide using calcined heteropolyacids on oxide supports
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Reaction of an alkene with aqueous hydrogen peroxide and a catalytic quantity of a heteropolyacid adsorbed onto magnesium, aluminium or zinc oxide leads to complete, rapid cleavage of the alkene to give carbonyl compounds.
- Brooks, Christopher D.,Huang, Ling-Chu,McCarron, Moya,Johnstone, Robert A. W.
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- Hydrocarboxylation of olefins by supported aqueous-phase catalysis
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Pd-TPPTS complexes supported on acidic macro-porous resins (Pd-TPPTS/resin) have been employed for the hydrocarboxylation of 1-hexene and styrene derivatives by supported aqueous phase catalysis (SAPC). Acidic macroporous resins acted as substitutes for both heterogeneous acids and supports of Pd-TPPTS complexes afforded many advantages, such as easy separation from organic products and good reusability. The prepared Pd-TPPTS/resin catalysts were characterized by FT-IR, TG, SEM and N2 physisorption, which demonstrated that the Pd-TPPTS complexes were loaded on the resin. Compared with homogeneous analogue, the present SAP catalyst offered higher total acid yield and selectivity towards linear acid in the hydrocarboxylation of 1-hexene. Moreover, it was found that water had a significant influence on the catalytic activity and selectivity toward linear acid over the SAP catalyst. Optimum water/resin ratio at about 66.7% in the SAP catalyst afforded maximum activity under the given reaction temperature. The present SAP catalyst was highly Pd-leaching resistant and can be reused at least four times without obvious loss in activity.
- He, Zhenhong,Hou, Zhenshan,Zhang, Yagang,Wang, Tianfu,Dilixiati, Yierxiati,Eli, Wumanjiang
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- Conjugate addition of organolithium reagents to α,β- unsaturated carboxylic acids
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Conjugate addition of primary, secondary, tertiary alkyl and phenyl lithium reagents to 2-alkenoic acids affords good yields of branched saturated carboxylic acids. Substitution by methyl groups at the α-carbon strongly decreases reactivity, whereas deprotonation of the starting acid occurs almost exclusively with methyl substitution at the β-carbon of the 2- alkenoic acid.
- Aurell, Maria Jose,Mestres, Ramon,Munoz, Elena
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- Green, homogeneous oxidation of alcohols by dimeric copper(II) complexes
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Three pyrazole derivatives, 3,5-dimethyl-1H-pyrazole (DMPz) (I), 3-methyl-5-phenyl-1H-pyrazole (MPPz) (II), and 3,5-diphenyl-1H-pyrazole (DPPz) (III), were prepared via reacting semicarbazide hydrochloride with the acetylacetone, 1-phenylbutane-1,3-dione, and 1,3-diphenylpropane-1,3-dione, respectively. Complexes 1–3 were isolated by reacting CuCl2·2H2O with I–III, respectively, and characterized by CHNS elemental analyses, FT-IR, UV-Vis, 1H and 13C NMR, EPR spectra, and TGA/DTA. Molecular structures of the pyrazole derivatives I–III and copper(II) complexes 2 and 3 were studied through single-crystal XRD analysis to confirm their molecular structures. Overlapping of hyperfine splitting in the EPR spectra of the dimeric copper(II) complexes 1–3 indicates that both copper centers do not possess the same electronic environment in solution. The copper(II) complexes are dimeric in solid state as well as in solution and catalyze the oxidation of various primary and secondary alcohols selectively. Catalysts 1–3 show more than 92% product selectivity toward ketones during the oxidation of secondary alcohols. Surprisingly primary alcohols, which are relatively difficult to oxidize, produce carboxylic acid as a major product (48%–90% selectivity) irrespective of catalytic systems. The selectivity for carboxylic acid rises with decreasing the carbon chain length of the alcohols. An eco-friendly and affordable catalytic system for oxidation of alcohols is developed by the utilization of H2O2, a green oxidant, and water, a clean and greener solvent, which is a notable aspect of the study.
- Maurya, Abhishek,Haldar, Chanchal
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p. 885 - 904
(2020/12/18)
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- Ruthenium-catalysed hydroxycarbonylation of olefins
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State-of-the-art catalyst systems for hydroxy- and alkoxycarbonylations of olefins make use of palladium complexes. In this work, we report a complementary ruthenium-catalysed hydroxycarbonylation of olefins applying an inexpensive Ru-precursor (Ru3(CO)12) and PCy3as a ligand. Crucial for the success of this transformation is the use of hexafluoroisopropanol (HFIP) as the solvent in the presence of an acid co-catalyst (PTSA). Overall, moderate to good yields are obtained using aliphatic olefins including the industrially relevant substrate di-isobutene. This atom-efficient catalytic transformation provides straightforward access to various carboxylic acids from unfunctionalized olefins.
- Dühren, Ricarda,Kucmierczyk, Peter,Jackstell, Ralf,Franke, Robert,Beller, Matthias
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p. 2026 - 2030
(2021/04/09)
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- Hydrolysis of amides to carboxylic acids catalyzed by Nb2O5
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Hydrolysis of amides to carboxylic acids is an industrially important reaction but is challenging due to the difficulty of cleaving the resonance stabilized amidic C-N bond. Twenty-three heterogeneous and homogenous catalysts were examined in the hydrolysis of acetamide. Results showed that Nb2O5was the most effective heterogeneous catalyst with the greatest yield of acetic acid. A series of Nb2O5catalysts calcined at various temperatures were characterized and tested in the hydrolysis of acetamide to determine the effects of crystal phase and surface properties of Nb2O5on catalytic performance. The high catalytic performance observed was attributed mainly to the facile activation of the carbonyl bond by Lewis acid sites that function even in the presence of basic inhibitors (NH3and H2O). The catalytic studies showed the synthetic advantages of the present method, such as simple operation, catalyst recyclability, additive free, solvent free, and wide substrate scope (>40 examples; up to 95% isolated yield).
- Siddiki,Rashed, Md. Nurnobi,Touchy, Abeda Sultana,Jamil, Md. A. R.,Jing, Yuan,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-Ichi
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p. 1949 - 1960
(2021/03/26)
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- FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES
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The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
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Paragraph 0008; 0175; 0206
(2021/06/22)
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- Hydroxycarbonylation of alkenes with formic acid using a rhodium iodide complex and alkyl ammonium iodide
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Hydroxycarbonylation of alkenes using formic acid (HCOOH) is ideal for the synthesis of various carboxylic acids as a means to develop a sustainable reaction system with lower environmental impact. In this study, we developed a new catalytic system for hydroxycarbonylation of alkenes with HCOOH using a Vaska-type Rh complex with an iodide ligand, RhI(CO)(PPh3)2(1), as the catalyst, and a quaternary ammonium iodide salt as the promoter for the catalyst. In comparison with similar reaction systems using Rh catalysts, our reaction system is safer and more environmentally friendly since it does not require high-pressure conditions, explosive gases, or environmentally unfriendly CH3I and extra PPh3promoters. In addition, we also experimentally clarified that the catalytic reaction proceedsviaRhHI2(CO)(PPh3)2(2), which is formed by the reaction of1with a quaternary ammonium iodide salt andp-TsOH. Furthermore, the Rh(iii) complex2can catalyze hydroxycarbonylation of alkenes with HCOOH without any promoters.
- Okada, Masaki,Takeuchi, Katsuhiko,Matsumoto, Kazuhiro,Oku, Tomoharu,Choi, Jun-Chul
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supporting information
p. 8727 - 8734
(2021/10/22)
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- Solvent-free oxidation of straight-chain aliphatic primary alcohols by polymer-grafted vanadium complexes
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Oxidovanadium(IV) complexes [VO(tertacac)2] (1), [VO(dipd)2] (2), and [VO(phbd)2] (3) were synthesized by reacting [VO(acac)2] with 2,2,6,6-tetramethyl-3,5-hepatanedione, 1,3-diphenyl-1,3-propanedione, and 1-phenyl-1,3-butanedione, respectively. Imidazole-modified Merrifield resin was used for the heterogenization of complexes 1–3. During the process of heterogenization, the V4+ center in complex 2 converts into V5+, whereas the other two complexes 1 and 3 remain in the oxidovanadium(IV) state in the polymer matrix. Theoretically, calculated IPA values of 1–3 suggest that 2 is prone to oxidation compared with 1 and 3, which was also supported by the absence of EPR lines in 5. Polymer-supported complexes Ps-Im-[VIVO(tertacac)2] (4), Ps-Im-[VVO2(dipd)2] (5), and Ps-Im-[VIVO(phbd)2] (6) were applied for the solvent-free heterogenous oxidation of a series of straight-chain aliphatic alcohols in the presence of H2O2 at 60°C and showed excellent substrate conversion specially for the alcohols with fewer carbon atoms. Higher reaction temperature improves the substrate conversion significantly for the alcohols containing more carbon atoms such as 1-pentanol, 1-hexanol, and 1-heptanol while using optimized reaction conditions. However, alcohols with fewer carbon atoms seem less affected by reaction temperatures higher than the optimized temperature. A decreasing trend in the selectivity(%) of carboxylic acid was observed with increasing carbon atoms among the examined alcohols, whereas the selectivity towards aldehydes increased. The order of efficiency of the supported catalysts is 4 > 6 > 5 in terms of turnover frequency (TOF) values and substrate conversion, further supported by theoretical calculations.
- Chaudhary, Nikita,Haldar, Chanchal,Kachhap, Payal
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- Cobalt-Catalyzed Acceptorless Dehydrogenation of Alcohols to Carboxylate Salts and Hydrogen
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The facile oxidation of alcohols to carboxylate salts and H2 is achieved using a simple and readily accessible cobalt pincer catalyst (NNNHtBuCoBr2). The reaction follows an acceptorless dehydrogenation pathway and displays good functional group tolerance. The amine-amide metal-ligand cooperation in cobalt catalyst is suggested to facilitate this transformation. The mechanistic studies indicate that in-situ-formed aldehydes react with a base through a Cannizzaro-type pathway, resulting in potassium hemiacetolate, which further undergoes catalytic dehydrogenation to provide the carboxylate salts and H2
- Gunanathan, Chidambaram,Kishore, Jugal,Pattanaik, Sandip,Pradhan, Deepak Ranjan
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supporting information
(2020/03/03)
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- Palladium supported on a novel ordered mesoporous polypyrrole/carbon nanocomposite as a powerful heterogeneous catalyst for the aerobic oxidation of alcohols to carboxylic acids and ketones on water
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Preparation of an ordered mesoporous polypyrrole/carbon (PPy/OMC) composite has been described through a two-step nanocasting process using KIT-6 as a template. Characterization of the PPy/OMC nanocomposite by various analysis methods such as TEM, XRD, TGA, SEM and N2 sorption confirmed the preparation of a material with ordered mesoporous structure, uniform pore size distribution, high surface area and high stability. This nanocomposite was then used for the immobilization of palladium nanoparticles. The nanoparticles were almost uniformly distributed on the support with a narrow particle size of 20-25 nm, confirmed by various analysis methods. Performance of the Pd?PPy/OMC catalyst was evaluated in the aerobic oxidation of various primary and secondary alcohols on water as a green solvent, giving the corresponding carboxylic acids and ketones in high yields and excellent selectivity. The catalyst could also be reused for at least 10 reaction runs without losing its catalytic activity and selectivity. High catalytic efficiency of the catalyst can be attributed to a strong synergism between the PPy/OMC and that of supported Pd nanoparticles.
- Ganji, Nasim,Karimi, Babak,Najafvand-Derikvandi, Sepideh,Vali, Hojatollah
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p. 13616 - 13631
(2020/04/24)
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- Method for preparing carboxylic acid by green catalytic oxidation of aliphatic primary alcohol
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The invention relates to a method for preparing carboxylic acid by green catalytic oxidation of aliphatic primary alcohol. The method comprises the following steps of: adding aliphatic primary alcoholinto a reaction solvent, adding an N-hydroxyphthalimide-copper oxide catalyst, introducing oxygen during reaction, and carrying out reaction at 50-80DEG C under normal pressure for 6-24h to obtain carboxylic acid with high yield. Compared with the prior art, the method has the advantages that the oxidizing agent is green and environment-friendly, the catalyst is cheap and easy to prepare, easy toseparate from the product, convenient to recycle, the reaction conditions are mild and the like, therefore the method is a green oxidation method of aliphatic primary alcohol.
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Paragraph 0059-0062
(2020/12/30)
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- Oxidation of aromatic and aliphatic aldehydes to carboxylic acids by Geotrichum candidum aldehyde dehydrogenase
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Oxidation reaction is one of the most important and indispensable organic reactions, so that green and sustainable catalysts for oxidation are necessary to be developed. Herein, biocatalytic oxidation of aldehydes was investigated, resulted in the synthesis of both aromatic and aliphatic carboxylic acids using a Geotrichum candidum aldehyde dehydrogenase (GcALDH). Moreover, selective oxidation of dialdehydes to aldehydic acids by GcALDH was also successful.
- Hoshino, Tomoyasu,Yamabe, Emi,Hawari, Muhammad Arisyi,Tamura, Mayumi,Kanamaru, Shuji,Yoshida, Keisuke,Koesoema, Afifa Ayu,Matsuda, Tomoko
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- Two-way homologation of aliphatic aldehydes: Both one-carbon shortening and lengthening via the same intermediate
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Aliphatic aldehydes can be homologated to both one-carbon shorter and one-carbon longer homologous carbonyl compounds through the 2–4 steps of reactions via the same intermediates, β,γ-unsaturated α-nitrosulfones, prepared from the proline-catalyzed sequential reactions of several aliphatic aldehydes with phenylsulfonylnitromethane. While the oxidative cleavage of the key intermediates gave one-carbon less homologous carbonyl compounds, the reduction of the same key intermediates followed by an oxidation produced one-carbon more homologous carbonyl compounds.
- Yoo, Jae Won,Seo, Youngran,Park, Jong Beom,Kim, Young Gyu
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- The plant pathogen enzyme AldC is a long-chain aliphatic aldehyde dehydrogenase
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Aldehyde dehydrogenases are versatile enzymes that serve a range of biochemical functions. Although traditionally considered metabolic housekeeping enzymes because of their ability to detoxify reactive aldehydes, like those generated from lipid peroxidation damage, the contributions of these enzymes to other biological processes are widespread. For example, the plant pathogen Pseudomonas syringae strain PtoDC3000 uses an indole-3-acetaldehyde dehydrogenase to synthesize the phytohormone indole-3-acetic acid to elude host responses. Here we investigate the biochemical function of AldC from PtoDC3000. Analysis of the substrate profile of AldC suggests that this enzyme functions as a long-chain aliphatic aldehyde dehydrogenase. The 2.5 ? resolution X-ray crystal of the AldC C291A mutant in a dead-end complex with octanal and NAD1 reveals an apolar binding site primed for aliphatic aldehyde substrate recognition. Functional characterization of site-directed mutants targeting the substrate- and NAD(H)-binding sites identifies key residues in the active site for ligand interactions, including those in the “aromatic box” that define the aldehyde-binding site. Overall, this study provides molecular insight for understanding the evolution of the prokaryotic aldehyde dehydrogenase superfamily and their diversity of function.
- Lee, Soon Goo,Harline, Kate,Abar, Orchid,Akadri, Sakirat O.,Bastian, Alexander G.,Chen, Hui-Yuan S.,Duan, Michael,Focht, Caroline M.,Groziak, Amanda R.,Kao, Jesse,Kottapalli, Jagdeesh S.,Leong, Matthew C.,Lin, Joy J.,Liu, Regina,Luo, Joanna E.,Meyer, Christine M.,Mo, Albert F.,Pahng, Seong Ho,Penna, Vinay,Raciti, Chris D.,Srinath, Abhinav,Sudhakar, Shwetha,Tang, Joseph D.,Cox, Brian R.,Holland, Cynthia K.,Cascella, Barrie,Cruz, Wilhelm,McClerkin, Sheri A.,Kunkel, Barbara N.,Jez, Joseph M.
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p. 13914 - 13926
(2020/12/09)
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- Method for preparing carboxylic acid by catalyzing aldehyde oxidation with N-heterocyclic carbene
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The invention discloses a method for preparing carboxylic acid by catalyzing aldehyde oxidation with N-heterocyclic carbene, and relates to the field of catalytic technology. The method comprises thefollowing steps: taking deionized water as a solvent and aldehyde as a reaction substrate, adding alkali into a reaction system, taking air as an oxidant and N-heterocyclic carbene as a catalyst required by the reaction, and carrying out catalytic oxidation on aldehyde at room temperature to 80 DEG C to generate a corresponding reaction product. The method has the beneficial effects that the N-heterocyclic carbene is used as the catalyst, no organic solvent is needed in the reaction process, the reaction process is green and safe, and the reaction yield is high.
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Paragraph 0039-0043; 0048-0051
(2020/11/25)
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- Process for the preparation of fatty acids
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The invention discloses a method for preparing fatty acid. The method comprises the following steps: providing a first reactant which is a furan compound containing an carbonyl group; providing a second reactant which is a compound containing a carboxyl group, an ester group or an anhydride group and can participate in a condensation reaction with the carbonyl group of the first reactant; allowingthe first reactant and the second reactant to participate in a first condensation reaction, and allowing a C=O bond of the carbonyl group of the first reactant to be connected with alpha carbon of the carbonyl group of the second reactant and to be converted into a C=C bond so as to form a condensation product; and carrying out a second-step reaction under hydrogen pressure in the presence of a co-catalytic system of a hydrogenation catalyst and Lewis acid, opening a furan ring of the condensation product, carrying out hydrodeoxygenation at the same time, removing all oxygen except for oxygenin the carboxyl group, and allowing a carbon chain to be saturated so as to obtain the fatty acid.
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Paragraph 0179-0206; 0216-0218
(2020/09/04)
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- Flexible polyurethanes, renewable fuels, and flavorings from a microalgae oil waste stream
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Renewable polymers have become an important focus in next-generation materials, and algae biomass offers an environmentally low-impact feedstock that can serve multiple uses. This study aims to develop a scalable methodology for production of microalgae-based polyols for polyurethane synthesis from waste oils derived from algae biomass. Following separation of omega-3 fatty acids from algae oil, residual oils can offer valuable building blocks for petrochemical replacements. However, unlike vegetable oils, algae oils contain organic contaminants, including photosynthetic pigments and hydrophobic cofactors that can complicate preparative methodologies. Here we convert and purify waste streams from omega-3 depleted Nannochloropsis salina algae oil, with major components consisting of palmitic and palmitoleic acid, into azelaic acid (AA) as a building block for flexible polyurethanes, with a simultaneous production of heptanoic acid (HA) as a flavor and fragrance precursor. Conversion of free fatty acid mixtures into a soft soap allows extraction of organic contaminants, and urea complexation provides isolated palmitoleic acid, which is subsequently ozonolyzed to produce AA and HA. Bio-based polyester diols are prepared from AA via esterification to provide a polyol monomer for flexible polyurethane foam preparation. The HA co-product is modified to produce the flavoring agent methyl heptanoate and also decarboxylated to produce hexane as a renewable solvent. This scalable process can be performed on oils from multiple algal species, offering valuable monomers from a highly sustainable source.
- Burkart, Michael D.,Griffin, Graham,Mayfield, Stephen P.,Neelakantan, Nitin,Phung Hai, Thien An,Pomeroy, Robert,Sherman, Suryendra D.,Tessman, Marissa
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supporting information
p. 3088 - 3094
(2020/06/17)
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- PRODUCTION METHOD OF AMIDE COMPOUND
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PROBLEM TO BE SOLVED: To provide a production method of an amide compound, which can use a variety of carboxylic acid halides and can produce a desired amide compound at a yield higher than a batch process by suppressing a side reaction. SOLUTION: Provided is a production method of an amide compound using a flow type reactor, in which the flow type reactor includes: a first flow path; a second flow path; a first mixing means provided at a confluent part of the first flow path and the second flow path; and a third flow path that is connected to the first mixing means and arranged on a down stream side of the first mixing means, the production method comprising: a mixing step of obtaining a mixed liquid by circulating a first liquid containing the carboxylic acid halide in the first flow path, circulating a second liquid containing an amine compound having a molecular weight of 1,000 or less, an inorganic alkali and water in the second flow path, and mixing the first liquid and the second liquid by the first mixing means to obtain a mixture; and a reaction step of obtaining an amide compound by circulating the mixed liquid in the third flow path and reacting the carboxylic acid halide and the amine compound in the third flow path. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2020,JPO&INPIT
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Paragraph 0134-0137
(2020/10/08)
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- Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
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The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
- Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 14365 - 14373
(2019/09/06)
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- Dehydrogenation of Alcohols to Carboxylic Acid Catalyzed by in Situ-Generated Facial Ruthenium- CPP Complex
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A selective catalytic system for the dehydrogenation of primary alcohols to carboxylic acids using a facial ruthenium complex generated in situ from the [Ru(COD)Cl2]n and a hybrid N-heterocyclic carbene (NHC)-phosphine-phosphine ligand (CPP) has been first reported. The facial coordination model was unveiled by NMR analysis of the reaction mixture. Such a fac-ruthenium catalyst system exhibited high catalytic activity and stability, and a high turnover number of 20 000 could be achieved with catalyst loading as low as 0.002 mol %. The exceedingly high catalyst stability was tentatively attributed to both the anchoring role of NHC and the hemi-lability of phosphines. The catalytic system also features a wide substrate scope. In particular, the facial coordination of CPP ligands was found to be beneficial for sterically hindered alcohols, and ortho-substituted benzylic alcohols and bulky adamantanyl methanol as well as cholesterol were all found to be viable dehydrogenation substrates.
- Liu, Hui-Min,Jian, Lei,Li, Chao,Zhang, Chun-Chun,Fu, Hai-Yan,Zheng, Xue-Li,Chen, Hua,Li, Rui-Xiang
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supporting information
p. 9151 - 9160
(2019/08/12)
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- Bidentate Ru(ii)-NC complexes as catalysts for the dehydrogenative reaction from primary alcohols to carboxylic acids
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Four Ru(ii)-NC complexes were synthesized by one-step processes from the corresponding NC ligands with RuHCl(CO)(PPh3)3. These complexes were tested as catalysts for alcohol dehydrogenative reactions, and complex {(C5H4N)-(C6H4)}RuCl(CO)(PPh3)2 (1) showed the highest activity. With KOH as the nucleophile and 0.5 mol% catalyst loading, a series of carboxylic acids were synthesized in toluene without any oxidant. Catalyst 1 could be transformed to complex {(C5H4N)-(C6H4)}RuH(CO)(PPh3)2 (6) when treated with KOH and benzyl alcohol. Complex 6 further reacted with PhCHO and H2O to generate product {(C5H4N)-(C6H4)}Ru(OCOPh)(CO)(PPh3)2 (7). Complexes 6 and 7 exhibited similar efficiency to complex 1, suggesting that they can be regarded as the catalytic intermediates of 1.
- Gong, Dawei,Hu, Bowen,Chen, Dafa
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p. 8826 - 8834
(2019/06/24)
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- SYNTHESIS OF HYPERVALENT IODINE REAGENTS WITH DIOXYGEN
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Methods of synthesis of hypervalent iodine reagents and methods for oxidation of organic compounds are disclosed.
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Paragraph 0165-0168
(2019/01/15)
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- Organocatalyzed Aerobic Oxidation of Aldehydes to Acids
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The first example organocatalyzed aerobic oxidation of aldehydes to carboxylic acids in both organic solvent and water under mild conditions is developed. As low as 5 mol % N-hydroxyphthalimide was used as the organocatalyst, and molecular O2 was used as the sole oxidant. No transition metals or hazardous oxidants or cocatalysts were involved. A wide range of carboxylic acids bearing diverse functional groups were obtained from aldehydes, even from alcohols, in high yields.
- Dai, Peng-Fei,Qu, Jian-Ping,Kang, Yan-Biao
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supporting information
p. 1393 - 1396
(2019/02/26)
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- Biocatalytic N-Alkylation of Amines Using Either Primary Alcohols or Carboxylic Acids via Reductive Aminase Cascades
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The alkylation of amines with either alcohols or carboxylic acids represents a mild and safe alternative to the use of genotoxic alkyl halides and sulfonate esters. Here we report two complementary one-pot systems in which the reductive aminase (RedAm) from Aspergillus oryzae is combined with either (i) a 1° alcohol/alcohol oxidase (AO) or (ii) carboxylic acid/carboxylic acid reductase (CAR) to affect N-alkylation reactions. The application of both approaches has been exemplified with respect to substrate scope and also preparative scale synthesis. These new biocatalytic methods address issues facing alternative traditional synthetic protocols such as harsh conditions, overalkylation and complicated workup procedures.
- Ramsden, Jeremy I.,Heath, Rachel S.,Derrington, Sasha R.,Montgomery, Sarah L.,Mangas-Sanchez, Juan,Mulholland, Keith R.,Turner, Nicholas J.
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p. 1201 - 1206
(2019/01/21)
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- Regioselectivity inversion tuned by iron(iii) salts in palladium-catalyzed carbonylations
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Impactful regioselectivity control is crucial for cost-effective chemical synthesis. By using cheap and abundant iron(iii) salts, the hydroxycarbonylations of both aromatic and aliphatic alkenes were significantly enhanced in both reactivity and selectivity (iso/n or n/iso up to >99:1). Moreover, Pd-catalyzed carbonylation selectivity can be switched from branched to linear by using different Fe(iii) salts. In addition, similar results were obtained for the carbonylation of secondary alcohols.
- Huang, Zijun,Cheng, Yazhe,Chen, Xipeng,Wang, Hui-Fang,Du, Chen-Xia,Li, Yuehui
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supporting information
p. 3967 - 3970
(2018/04/23)
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- Zinc Oxide-Catalyzed Dehydrogenation of Primary Alcohols into Carboxylic Acids
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Zinc oxide has been developed as a catalyst for the dehydrogenation of primary alcohols into carboxylic acids and hydrogen gas. The reaction is performed in mesitylene solution in the presence of potassium hydroxide, followed by workup with hydrochloric acid. The transformation can be applied to both benzylic and aliphatic primary alcohols and the catalytically active species was shown to be a homogeneous compound by a hot filtration test. Dialkylzinc and strongly basic zinc salts also catalyze the dehydrogenation with similar results. The mechanism is believed to involve the formation of a zinc alkoxide which degrades into the aldehyde and a zinc hydride. The latter reacts with the alcohol to form hydrogen gas and regenerate the zinc alkoxide. The degradation of a zinc alkoxide into the aldehyde upon heating was confirmed experimentally. The aldehyde can then undergo a Cannizzaro reaction or a Tishchenko reaction, which in the presence of hydroxide leads to the carboxylic acid.
- Monda, Fabrizio,Madsen, Robert
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supporting information
p. 17832 - 17837
(2018/11/23)
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- Oxidation Catalysis by an Aerobically Generated Dess–Martin Periodinane Analogue
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Hypervalent iodine(V) reagents, such as Dess–Martin periodinane (DMP) and 2-iodoxybenzoic acid (IBX), are broadly useful oxidants in chemical synthesis. Development of strategies to generate these reagents from dioxygen (O2) would immediately enable use of O2 as a terminal oxidant in a broad array of substrate oxidation reactions. Recently we disclosed the aerobic synthesis of I(III) reagents by intercepting reactive oxidants generated during aldehyde autoxidation. In this work, aerobic oxidation of iodobenzenes is coupled with disproportionation of the initially generated I(III) compounds to generate I(V) reagents. The aerobically generated I(V) reagents exhibit substrate oxidation chemistry analogous to that of DMP. The developed aerobic generation of I(V) has enabled the first application of I(V) intermediates in aerobic oxidation catalysis.
- Maity, Asim,Hyun, Sung-Min,Wortman, Alan K.,Powers, David C.
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supporting information
p. 7205 - 7209
(2018/05/29)
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- A aldehyde or mellow directly converted into the carboxylic acid (by machine translation)
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The invention discloses a aldehyde or mellow oxidation can be directly transformed into carboxylic acid, is characterized in that the pure oxygen environment, in N - hydroxy imide compound under the catalysis of the imide compound or N - hydroxy and nitrous acid ester compound common under the catalysis, the CH2 OH and CHO oxidation directly converted into the carboxylic acid compounds. The invention using oxygen as the oxidizing agent, does not add any metal catalyst, environment-friendly, high catalytic efficiency, simple and convenient operation. With the previous metal catalytic system complex and different catalytic system, has some metal catalytic system in the process, the use of transition metal will cause the transition metal of the residual, the invention adopts the non-metallic catalytic system, environmental protection, preventing the metal residue problem, this to the solution of the drug in the synthesis of transition metal residue problem and provides a new method of thinking. (by machine translation)
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Paragraph 0019; 0020
(2018/08/03)
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- A biocatalytic method for the chemoselective aerobic oxidation of aldehydes to carboxylic acids
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Herein, we present a study on the oxidation of aldehydes to carboxylic acids using three recombinant aldehyde dehydrogenases (ALDHs). The ALDHs were used in purified form with a nicotinamide oxidase (NOx), which recycles the catalytic NAD+ at the expense of dioxygen (air at atmospheric pressure). The reaction was studied also with lyophilised whole cell as well as resting cell biocatalysts for more convenient practical application. The optimised biocatalytic oxidation runs in phosphate buffer at pH 8.5 and at 40 °C. From a set of sixty-one aliphatic, aryl-Aliphatic, benzylic, hetero-Aromatic and bicyclic aldehydes, fifty were converted with elevated yield (up to >99%). The exceptions were a few ortho-substituted benzaldehydes, bicyclic heteroaromatic aldehydes and 2-phenylpropanal. In all cases, the expected carboxylic acid was shown to be the only product (>99% chemoselectivity). Other oxidisable functionalities within the same molecule (e.g. hydroxyl, alkene, and heteroaromatic nitrogen or sulphur atoms) remained untouched. The reaction was scaled for the oxidation of 5-(hydroxymethyl)furfural (2 g), a bio-based starting material, to afford 5-(hydroxymethyl)furoic acid in 61% isolated yield. The new biocatalytic method avoids the use of toxic or unsafe oxidants, strong acids or bases, or undesired solvents. It shows applicability across a wide range of substrates, and retains perfect chemoselectivity. Alternative oxidisable groups were not converted, and other classical side-reactions (e.g. halogenation of unsaturated functionalities, Dakin-Type oxidation) did not occur. In comparison to other established enzymatic methods such as the use of oxidases (where the concomitant oxidation of alcohols and aldehydes is common), ALDHs offer greatly improved selectivity.
- Knaus, Tanja,Tseliou, Vasilis,Humphreys, Luke D.,Scrutton, Nigel S.,Mutti, Francesco G.
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supporting information
p. 3931 - 3943
(2018/09/11)
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- Highly efficient oxidative cleavage of alkenes and cyanosilylation of aldehydes catalysed by magnetically recoverable MIL-101
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The catalytic activity of magnetically recoverable MIL-101 was investigated in the oxidation of alkenes to carboxylic acids and cyanosilylation of aldehydes. MIL-101 was treated with Fe3O4 and the prepared catalyst was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption measurements, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and inductively coupled plasma analysis. The catalytic active sites in this heterogeneous catalyst are Cr3+ nodes of the MIL-101 framework. This heterogeneous catalyst has the advantages of excellent yields, short reaction times and reusability several times without significant decrease in its initial activity and stability in both oxidation and cyanosilylation reactions. Its magnetic property allows its easy separation using an external magnetic field.
- Nourian, Maryam,Zadehahmadi, Farnaz,Kardanpour, Reihaneh,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
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- Mesoporous silica as phase transfer agent in the biphasic oxidative cleavage of alkenes using triazole complexes of ruthenium as catalyst precursors
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The oxidative cleavage of alkenes was performed using ruthenium triazole -arene complexes immobilized on mesoporous silica materials. These silica-organometallic hybrid materials were found to show enhanced activity when compared to conventional homogeneous systems even when operating at a relatively low catalyst loading. The enhanced catalytic performance of these heterogeneous systems can be attributed to the mesoporous silica acting as a phase transfer agent in the biphasic catalyst system.
- Leckie, Laura,Mapolie, Selwyn F.
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- Cis -Oxoruthenium complexes supported by chiral tetradentate amine (N4) ligands for hydrocarbon oxidations
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We report the first examples of ruthenium complexes cis-[(N4)RuIIICl2]+ and cis-[(N4)RuII(OH2)2]2+ supported by chiral tetradentate amine ligands (N4), together with a high-valent cis-dioxo complex cis-[(N4)RuVI(O)2]2+ supported by the chiral N4 ligand mcp (mcp = N,N′-dimethyl-N,N′-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine). The X-ray crystal structures of cis-[(mcp)RuIIICl2](ClO4) (1a), cis-[(Me2mcp)RuIIICl2]ClO4 (2a) and cis-[(pdp)RuIIICl2](ClO4) (3a) (Me2mcp = N,N′-dimethyl-N,N′-bis((6-methylpyridin-2-yl)methyl)cyclohexane-1,2-diamine, pdp = 1,1′-bis(pyridin-2-ylmethyl)-2,2′-bipyrrolidine)) show that the ligands coordinate to the ruthenium centre in a cis-α configuration. In aqueous solutions, proton-coupled electron-transfer redox couples were observed for cis-[(mcp)RuIII(O2CCF3)2]ClO4 (1b) and cis-[(pdp)RuIII(O3SCF3)2]CF3SO3 (3c′). Electrochemical analyses showed that the chemically/electrochemically generated cis-[(mcp)RuVI(O)2]2+ and cis-[(pdp)RuVI(O)2]2+ complexes are strong oxidants with E° = 1.11-1.13 V vs. SCE (at pH 1) and strong H-atom abstractors with DO-H = 90.1-90.8 kcal mol-1. The reaction of 1b or its (R,R)-mcp counterpart with excess (NH4)2[CeIV(NO3)6] (CAN) in aqueous medium afforded cis-[(mcp)RuVI(O)2](ClO4)2 (1e) or cis-[((R,R)-mcp)RuVI(O)2](ClO4)2 (1e?), respectively, a strong oxidant with E(RuVI/V) = 0.78 V (vs. Ag/AgNO3) in acetonitrile solution. Complex 1e oxidized various hydrocarbons, including cyclohexane, in acetonitrile at room temperature, affording alcohols and/or ketones in up to 66% yield. Stoichiometric oxidations of alkenes by 1e or 1e? in tBuOH/H2O (5:1 v/v) afforded diols and aldehydes in combined yields of up to 98%, with moderate enantioselectivity obtained for the reaction using 1e?. The cis-[(pdp)RuII(OH2)2]2+ (3c)-catalysed oxidation of saturated C-H bonds, including those of ethane and propane, with CAN as terminal oxidant was also demonstrated.
- Tse, Chun-Wai,Liu, Yungen,Wai-Shan Chow, Toby,Ma, Chaoqun,Yip, Wing-Ping,Chang, Xiao-Yong,Low, Kam-Hung,Huang, Jie-Sheng,Che, Chi-Ming
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p. 2803 - 2816
(2018/03/21)
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- A carboxylate-bridged Mn(II) compound with 6-methylanthranilate/bipy: oxidation of alcohols/alkenes and catalase-like activity
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A novel manganese compound, [Mn2(μ1,3-6-CH3-2-NH2C6H4COO)2(bipy)4](ClO4)2 (bipy?=?2,2′-bipyridine), was synthesized and used as a catalyst precursor in the oxidation of alkenes and primary alcohols to corresponding aldehydes, ketones, and acids. The six-coordinate compound has a binuclear structure in which two Mn(II) ions adopt a syn-anti μ1,3-bridging mode with two carboxylate groups and two chelated bipy ligands. The compound exhibits good activity in the oxidation of cyclohexene to 2-cyclohexene-1-one as the major product (93% conv. in 3?h, 79.3% selectivity) and of cinnamyl alcohol to cinnamaldehyde as the major product with 46% selectivity (100% conv. in 1.5?h) with tert-butyl hydroperoxide (TBHP) in acetonitrile at 70?°C. Furthermore, the catalase-like activity of the compound was studied in different solvents (acetonitrile, methanol, Tris-HCl buffer; TOF?=?29,910?h?1 in Tris-HCl buffer).
- Kilic, Yalcin,Bolat, Serkan,Kani, Ibrahim
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p. 2293 - 2303
(2018/05/14)
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- Oxygen bridged Homobinuclear Mn(II) compounds with Anthranilic acid: Theoretical calculations, oxidation and catalase activity
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Two new homobinuclear manganese compounds with mixed ligands, [Mn2(μ1,1–2-NH2C6H4COO)2(phen)4](ClO4)2(CH3OH) (1), and [Mn2(μ1,3–2-NH2C6H4COO)2(bipy)4](ClO4)2 (2) (NH2C6H4COOH?=?anthranilic acid, bipy?=?2,2′-bipyridine, phen?=?1,10- phenanthroline) were synthesized and thoroughly characterized by elemental analysis, IR, UV and single crystal X-ray crystallography. X-ray structure analysis shows that in the mono- and bidentate carboxylate bridged compounds, Mn–Mn distances of 1 and 2 are 3,461??, and 4,639??, respectively. The energy of the compounds was determined with a DFT (Density Functional Theory) calculation on B3LYP/6-31G(d,p) optimized geometry by using the B3LYP/6-31G(d,p) basis set. These compounds acts as biomimetic catalyst and show catalase-like activity for the hydrogen peroxide dismutation at room temperature in different solvents with remarkable activity (TOF, Turnover frequency?=?mol of subst./(mol of cat. × time)) up to 12640?h?1 with 1, and 17910?h?1 with 2 in Tris–HCl buffer). Moreover, the catalytic activity of 1 and 2 has been studied for oxidation of alcohols (cinnamyl alcohol, benzyl alcohol, cyclohexanol, 1-octanol and 1-heptanol) and alkenes (cyclohexene, styrene, ethyl benzene, 1-octene and 1-hexene) in a homogeneous catalytic system consisting t-butylhydroperoxide (TBHP) as an oxidant in acetonitrile. Both compounds exhibited very high activity in the oxidation of cyclohexene to cyclohexanone (~80% selectivity, ~99% conversion in 1?h, TOF?=?243?h?1 and 226?h?1) and cinnamyl alcohol to cinnamaldehyde (~64% selectivity) as the main product with very high TOF value (9180?h?1 and 13040?h?1 in the first minute of reaction) (~100% conversion in 0.5?h) with TBHP at 70?°C in acetonitrile, for 1 and 2, respectively.
- Su, Esra,Guven, Alaettin,Kani, Ibrahim
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- Synthesis of medium-chain carboxylic acids or α,ω-dicarboxylic acids from cellulose-derived platform chemicals
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Medium-chain fatty acids and their derivatives have important applications in the energy and chemical industries. Thus, we have prepared a series of medium-chain fatty acids by the selective hydrodeoxygenation of the aldol condensation products derived from cellulose using a metal triflate and Pd/C catalyst system. The selective retention of the carboxyl group is a notable feature of this catalytic system.
- Li, Xing-Long,Zhang, Kun,Jiang, Ju-Long,Zhu, Rui,Wu, Wei-Peng,Deng, Jin,Fu, Yao
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supporting information
p. 362 - 368
(2018/02/07)
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- Process for producing long chain amino acids and dibasic acids
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There is disclosed a process for the production of long chain amino acid and long chain dibasic acid, comprising: (1) reacting long chain keto fatty acid with hydroxylamine or subjecting keto fatty acid to an ammoximation reaction to yield an oxime fatty acid; (2) subjecting the oxime fatty acid to the Beckmann rearrangement to yield a mixture of two amide fatty acids; (3) hydrolyzing the mixed amide fatty acids to produce long chain amino acid, long chain dibasic acid, short chain alkylamine, and alkanoic acid.
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- Structural transformation of porous polyoxometalate frameworks and highly efficient biomimetic aerobic oxidation of aliphatic alcohols
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Due to their inherent inert nature, it is difficult to oxidize unactivated aliphatic alcohols with molecular oxygen under mild conditions. Inspired by enzymatic catalysis, numerous biomimetic systems have been therefore established. However, low catalytic efficiency and easy auto-oxidative deactivation nature remain the problematic issues. To meet these challenges, we report herein a 2D porous polyoxometalate (POM) framework Gd4(H2O)26[WZn{Cu(H2O)}2(ZnW9O34)2]·24H2O (CZJ-11) and a 3D porous POM framework Gd4(H2O)24[WZn{Cu(H2O)}2(ZnW9O34)2]·11H2O (CZJ-12) transferred from CZJ-11 by partial dehydration, consisting of scaffolded redox-active Cu(II) sites in the sandwich-type POM cluster [WZn{Cu-(H2O)}2(ZnW9O34)2]12- (abbreviated as {Zn3Cu2W19}). To mimic the catalytic mechanism of enzymes, N-hydroxyphthalimide (NHPI) and tetramethylammonium bromide (TMAB) were introduced as cocatalysts, which performed as electron donor and electron-transfer mediator, respectively. The coupled catalyst systems demonstrate analogue properties with oxygenase enzymes in the aerobic oxidation of aliphatic alcohols under mild conditions. Compared with molecular POM counterpart and metalloporphyrins, the catalytic efficiency of these POM frameworks is predominant in aerobic oxidation of unactivated aliphatic alcohols by imitating the active sites and the catalytic mechanism of enzymes. Compared with metal-organic coordination complexes, such as metalloporphyrins, the pure inorganic frameworks offer significant superiority of robustness to auto-oxidation and simple recovery for recycling with retained high catalytic efficiency.
- Zhao, Min,Zhang, Xian-Wei,Wu, Chuan-De
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p. 6573 - 6580
(2017/11/09)
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- An Efficient Iron(III)-Catalyzed Aerobic Oxidation of Aldehydes in Water for the Green Preparation of Carboxylic Acids
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The first example of a heterogeneous iron(III)-catalyzed aerobic oxidation of aldehydes in water was developed. This method utilizes 1 atmosphere of oxygen as the sole oxidant, proceeds under extremely mild aqueous conditions, and covers a wide range of various functionalized aldehydes. Chromatography is generally not necessary for product purification. Its operational simplicity, gram-scale oxidation, and the ability to successively reuse the catalyst, make this new methodology environmentally benign and cost effective. The generality of this methodology gives it the potential to be used on an industrial scale.
- Yu, Han,Ru, Shi,Dai, Guoyong,Zhai, Yongyan,Lin, Hualin,Han, Sheng,Wei, Yongge
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p. 3867 - 3871
(2017/03/27)
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- Ruthenium on Carbon Catalysed Carbon-Carbon Cleavage of Aryl Alkyl Ketones and Aliphatic Aldehydes in Aqueous Media
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A new ruthenium on carbon-catalysed carbon–carbon (C?C) cleavage reaction of aryl alkyl ketone derivatives in water in the presence of CaO under atmospheric oxygen conditions has been developed. Corresponding benzoic acid derivatives were produced from various aryl alkyl ketones in excellent yields. CaO acts as an adsorbent of CO and CO2 to maintain a sufficient concentration of oxygen around the catalyst required for effective progress of the reaction. It was also revealed that aliphatic aldehydes were generated from the alkyl moiety of aryl alkyl ketones over the course of the reaction. The aliphatic aldehyde derivatives undergo either an oxidation to the corresponding aliphatic carboxylic acids or a further continuous C?C cleavage reaction to form aliphatic aldehydes with loss of one carbon along with the formation of CO and CO2. (Figure presented.).
- Hattori, Tomohiro,Okami, Hiroki,Ichikawa, Tomohiro,Mori, Shigeki,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
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supporting information
p. 3490 - 3495
(2017/09/06)
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- Efficient and selective oxidation of aldehydes with dioxygen catalysed by vanadium-containing heteropolyanions
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The heteropolyacids “H3+n[PMo12–nVnO40]·aq” (denoted as HPA-n; n = 2, 3, 8) catalyse the oxidation of aldehydes to carboxylic acids in the presence of dioxygen with very good yields. The effect on the catalytic activity of various parameters such as the precursors, solvent, temperature or catalyst/substrate ratio was examined. The process is particularly selective for linear and aromatic aldehydes. The oxidation of adipaldehyde with dioxygen in mild conditions, in the presence of HPA-2 as a catalyst, leads to the formation of adipic acid together with a significant amount of other byproducts. Thus, several modifications of the catalytic systems have been carried out to improve their selectivity. The effect of cocatalysts was investigated and, among the species tested, complex Ni(acac)2 was found to be the most efficient yielding 60% of adipic acid.
- El Amrani, Ikram,Atlamsani, Ahmed,Dakkach, Mohamed,Rodríguez, Montserrat,Romero, Isabel,Amthiou, Souad
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p. 888 - 895
(2017/09/26)
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- "release and catch" catalysis by tungstate species for the oxidative cleavage of olefins
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The oxidative cleavage of olefins produces valuable carbonyl compounds, and thus, the development of green catalytic methods using H2O2 as an oxidant is highly desired. In this work, we have successfully developed an efficient catalytic system for the oxidative cleavage of olefins and related compounds using H2O2. In the presence of tungstate species supported on zinc-modified tin dioxide (W/Zn-SnO2), the oxidative cleavage of 1-methyl-1-cyclohexene proceeds efficiently through multistep reaction pathways involving oxygenation, hydrolysis, perhydrolysis, and isomerization reactions. In this reaction system, active peroxotungstate species, generated by the reaction of the supported tungstate species with H2O2, are released into the solution during the course of the reaction. At the end of the reaction (after the complete consumption of H2O2), the released tungstate species are re-captured by the support. The W/Zn-SnO2 catalyst can be reused at least nine times for the oxidative cleavage of 1-methyl-1-cyclohexene without loss of catalytic performance and can be applied to the oxidation of various other substrate molecules.
- Yoshimura, Yu,Ogasawara, Yoshiyuki,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
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p. 1662 - 1670
(2017/07/22)
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- MIXED OXIDES FOR THE OXIDATIVE CLEAVAGE OF LIPIDS USING OXYGEN TO AFFORD MONO- AND DI-CARBOXYLIC ACIDS
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This invention relates to the synthesis of new catalysts based on earth crust abundant mixed oxides that can produce cleavage of fatty acids (FA), FA methyl esters, or even lipids in a single step using oxygen as oxidant in solventless conditions.
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Page/Page column 10-11
(2017/12/29)
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- Transition-Metal- and Halogen-Free Oxidation of Benzylic sp 3 C-H Bonds to Carbonyl Groups Using Potassium Persulfate
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Aryl carbonyl compounds including acetophenones, benzophenones, imides, and benzoic acids are prepared from benzyl substrates using potassium persulfate as oxidant with catalytic pyridine in acetonitrile under mild conditions. Neither transition metals nor halogens are involved in the reactions.
- Hu, Yixin,Zhou, Lihong,Lu, Wenjun
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supporting information
p. 4007 - 4016
(2017/08/29)
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- Site-Selective Catalytic Carboxylation of Unsaturated Hydrocarbons with CO2 and Water
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A catalytic protocol that reliably predicts and controls the site-selective incorporation of CO2 to a wide range of unsaturated hydrocarbons utilizing water as formal hydride source is described. This platform unlocks an opportunity to catalytically repurpose three abundant, orthogonal feedstocks under mild conditions.
- Gaydou, Morgane,Moragas, Toni,Juliá-Hernández, Francisco,Martin, Ruben
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supporting information
p. 12161 - 12164
(2017/09/12)
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- A Comprehensive Study on Metal Triflate-Promoted Hydrogenolysis of Lactones to Carboxylic Acids: From Synthetic and Mechanistic Perspectives
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Direct hydrogenolysis of lactone to carboxylic acid (i.e., hydrogenolysis of the Calkoxy-O bond with the carbonyl group untouched) is generally difficult, as the current strategies employing Br?nsted acids as the catalyst usually require harsh conditions such as a high temperature and a high H2 pressure. Herein, we report a developed solvent-free catalytic transformation, in which W(OTf)6 is believed to promote the hydrogenolysis process. This strategy could efficiently hydrogenate lactones to carboxylic acids under extra mild conditions (e.g., a reaction temperature of 2) and showed a broad substrate scope. In addition, the catalytic protocol can be further applied to the hydrogenolysis of polyhydroxyalkanoate, as a renewable polymer, to the corresponding straight-chain carboxylic acids. An extensive mechanistic study was subsequently performed, and the density functional theory calculations revealed a reaction pattern, including the complete cleavage of the C=O bond with the assistance of the W(OTf)6 catalyst. Moreover, the key intermediate created in the mechanism, as an oxonium with an OTf moiety, was successfully detected by electrospray ionization mass spectra. Through a comparison with the Br?nsted acid-catalyzed system, the study confirmed that the existence of the OTf moiety can significantly lower the barriers associated with the rearrangement and elimination processes. Meanwhile, emphasis was placed on the critical role that the anion plays, as well as the fact that the anion effect is directly related to the chemoselectivity.
- Zhu, Rui,Jiang, Ju-Long,Li, Xing-Long,Deng, Jin,Fu, Yao
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p. 7520 - 7528
(2017/11/10)
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