- Selective TEMPO-Oxidation of Alcohols to Aldehydes in Alternative Organic Solvents
-
The TEMPO-catalyzed oxidation of alcohols to aldehydes has emerged to one of the most widely applied methodologies for such transformations. Advantages are the utilization of sodium hypochlorite, a component of household bleach, as an oxidation agent and the use of water as a co-solvent. However, a major drawback of this method is the often occurring strict limitation to use dichloromethane as an organic solvent in a biphasic reaction medium with water. Previous studies show that dichloromethane cannot easily be substituted because a decrease of selectivity or inhibition of the reaction is observed by using alternative organic solvents. Thus, up to now, only a few examples are known in which after a tedious optimization of the reaction dichloromethane could be replaced. In order to overcome the current limitations, we were interested in finding a TEMPO-oxidation method in alternative organic solvents, which is applicable for various alcohol oxidations. As a result, we found a method for N-oxyl radical-catalyzed oxidation using sodium hypochlorite as an oxidation agent in nitriles as an organic solvent component instead of dichloromethane. Besides the oxidation of aromatic primary alcohols also aliphatic primary alcohols, secondary alcohols as well as dialcohols were successfully converted when using this method, showing high selectivity towards the carbonyl compound and low amounts of the acid side-product.
- Hinzmann, Alessa,Stricker, Michael,Busch, Jasmin,Glinski, Sylvia,Oike, Keiko,Gr?ger, Harald
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p. 2399 - 2408
(2020/04/29)
-
- Production of Hydroxy Acids: Selective Double Oxidation of Diols by Flavoprotein Alcohol Oxidase
-
Flavoprotein oxidases can catalyze oxidations of alcohols and amines by merely using molecular oxygen as the oxidant, making this class of enzymes appealing for biocatalysis. The FAD-containing (FAD=flavin adenine dinucleotide) alcohol oxidase from P. chrysosporium facilitated double and triple oxidations for a range of aliphatic diols. Interestingly, depending on the diol substrate, these reactions result in formation of either lactones or hydroxy acids. For example, diethylene glycol could be selectively and fully converted into 2-(2-hydroxyethoxy)acetic acid. Such a facile cofactor-independent biocatalytic route towards hydroxy acids opens up new avenues for the preparation of polyester building blocks.
- Fraaije, Marco W.,Martin, Caterina,Trajkovic, Milos
-
p. 4869 - 4872
(2020/02/11)
-
- An Engineered Alcohol Oxidase for the Oxidation of Primary Alcohols
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Structure-guided directed evolution of choline oxidase has been carried out by using the oxidation of hexan-1-ol to hexanal as the target reaction. A six-amino-acid variant was identified with a 20-fold increased kcat compared to that of the wild-type enzyme. This variant enabled the oxidation of 10 mm hexanol to hexanal in less than 24 h with 100 % conversion. Furthermore, this variant showed a marked increase in thermostability with a corresponding increase in Tm of 20 °C. Improved solvent tolerance was demonstrated with organic solvents including ethyl acetate, heptane and cyclohexane, thereby enabling improved conversions to the aldehyde by up to 30 % above conversion for the solvent-free system. Despite the evolution of choline oxidase towards hexan-1-ol, this new variant also showed increased specific activities (by up to 100-fold) for around 50 primary aliphatic, unsaturated, branched, cyclic, benzylic and halogenated alcohols.
- Heath, Rachel S.,Birmingham, William R.,Thompson, Matthew P.,Taglieber, Andreas,Daviet, Laurent,Turner, Nicholas J.
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p. 276 - 281
(2019/01/04)
-
- Cis -Oxoruthenium complexes supported by chiral tetradentate amine (N4) ligands for hydrocarbon oxidations
-
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
-
p. 2803 - 2816
(2018/03/21)
-
- Oxidation of terminal diols using an oxoammonium salt: A systematic study
-
A systematic study of the oxidation of a range of terminal diols is reported, employing the oxoammonium salt 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (4-NHAc-TEMPO+ BF4-) as the oxidant. For substrates bearing a hydrocarbon chain of seven carbon atoms or more, the sole product is the dialdehyde. A series of post-oxidation reactions have been performed showing that the product mixture resulting from the oxidation step can be taken on directly to a subsequent transformation. For diols containing four to six carbon atoms, the lactone product is the major product upon oxidation. In the case of 1,2-ethanediol and 1,3-propanediol, when using a 1 : 0.5 stoichiometric ratio of substrate to oxidant, the corresponding monoaldehyde is formed which reacts rapidly with further diol to yield the acetal product. This is of particular synthetic value given both the difficulty of their preparation using other approaches and also their potential application in further reaction chemistry.
- Miller, Shelli A.,Bobbitt, James M.,Leadbeater, Nicholas E.
-
supporting information
p. 2817 - 2822
(2017/04/04)
-
- Preparation method and application of brphinsted acidic ionic liquid using periodate as anion as well as method for preparing alpha,omega-dialdehyde
-
The invention relates to the field of fine chemical industry, and concretely provides an application of brphinsted acidic ionic liquid using periodate as an anion as well as a preparation method thereof. The invention provides a method for preparing alpha,omega-dialdehyde. The method comprises the following steps: in a condition of a solution, cycloolefin and/or alkylene oxide and an oxidizing agent are contacted, transparent liquid with white deposition is obtained, transparent liquid and white deposition are obtained by separation, wherein the oxidizing agent is brphinsted acidic ionic liquid using periodate as the anion. The brphinsted acidic ionic liquid using periodate as the anion can be used as an oxidizing agent for carrying out an oxidation reaction is provided for the first time, and the method has the advantages of simple and easily operated process, green and environmental protection, cleaning, and repeated recovery and utilization of the oxidizing agent.
- -
-
Paragraph 0130; 0131
(2017/05/12)
-
- NOVEL PROCESS FOR MAKING OMEGA-AMINOALKYLENIC ALKYL ESTER
-
A method for making a compound of formula (V): is provided. The method comprises converting a compound of formula (III): to the compound of formula (V), wherein A is a C6-C10 alkene group having at least one carbon-carbon double bond, B is a C6-C10 alkyl chain; and R1 is an alkyl group, and R3 is an oxygenated functional group.
- -
-
Paragraph 0184; 0185
(2016/08/17)
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- Dramatic Effect of Ancillary NHC Ligand in the Highly Selective Catalytic Oxidative Carbon-Carbon Multiple Bond Cleavage
-
Selective and controlled oxidation of olefins to aldehydes is a commonly used important transformation in chemistry. However, chemists still use the dangerous and inconvenient ozonolysis method or the less selective, low-yielding Lemieux-Johnson protocol. In a program of developing effective catalysts for this important reaction, we disclose here that an ancillary ligand can play a dramatic role in the above catalytic phenomenon, depending on the design of the ligand precursor chosen. Proof-of-principle is demonstrated with the help of two newly designed [LnRuII-NHC] precatalysts (NHC = an imidazolydene-based NHC, Im-NHC, or a triazolydene-based NHC, Trz-NHC; Ln = para-cymene) for catalytic selective oxidation of olefins/alkynes to carbonyl compounds. With the electron-deficient Trz-NHC ligand, [(para-cymene)RuII(Im-Trz)]+ precatalyst was found to be an order of magnitude more efficient than the [(para-cymene)RuII(Im-NHC)]+ precatalyst.
- Gupta, Suraj K.,Sahoo, Sandeep K.,Choudhury, Joyanta
-
supporting information
p. 2462 - 2466
(2016/08/16)
-
- Aerobic epoxidation catalysed by transition metal substituted polyfluorooxometalates
-
First row transition metal substituted polyfluorooxmetalates with quasi Wells-Dawson structures and a nitro terminal ligand, [NaH2M(NO2)W17F6O55]q-, were used as catalysts for the aerobic epoxidation of cyclic alkenes. The Cu(NO2) analog combined the best traits of conversion and selectivity. Some C-C bond cleavage was also observed and cis isomers reacted preferentially without stereochemical inversion indicating an oxygen atom to double bond concerted reaction.
- Bugnola, Marco,Neumann, Ronny
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p. 14534 - 14537
(2016/09/28)
-
- Iron Catalysis for Room-Temperature Aerobic Oxidation of Alcohols to Carboxylic Acids
-
Oxidation from alcohols to carboxylic acids, a class of essential chemicals in daily life, academic laboratories, and industry, is a fundamental reaction, usually using at least a stoichiometric amount of an expensive and toxic oxidant. Here, an efficient and practical sustainable oxidation technology of alcohols to carboxylic acids using pure O2 or even O2 in air as the oxidant has been developed: utilizing a catalytic amount each of Fe(NO3)3·9H2O/TEMPO/MCl, a series of carboxylic acids were obtained from alcohols (also aldehydes) in high yields at room temperature. A 55 g-scale reaction was demonstrated using air. As a synthetic application, the first total synthesis of a naturally occurring allene, i.e., phlomic acid, was accomplished.
- Jiang, Xingguo,Zhang, Jiasheng,Ma, Shengming
-
supporting information
p. 8344 - 8347
(2016/07/26)
-
- Comparison of “on water” and solventless procedures in the rhodium-catalyzed hydroformylation of diolefins, alkynes, and unsaturated alcohols
-
Catalytic systems containing Rh(acac)(CO)2 or Rh/PAA (PAA?=?polyacrylic acid) and hydrophobic phosphine (PPh3) were used in the hydroformylation of diolefins, alkynes, and unsaturated alcohols under solventless and “on water” conditions. The total yield of dialdehydes obtained from 1,5-hexadiene and 1,7-octadiene reached 99%, and regioselectivity towards linear dialdehydes was higher in the “on water” system. The tandem hydroformylation-hydrogenation of phenylacetylene led to the formation of saturated aldehydes (3-phenylpropanal and 2-phenylpropanal) at 98% conversion with a good regioselectivity towards the linear aldehyde in the “on water” reaction. In contrast, solventless conditions appeared better in the hydroformylation of 1-propen-3-ol. 4-Hydroxybutanal, formed in this reaction with an excellent selectivity, was next transformed to tetrahydrofuran-2-ol via a ring-closure process. Cyclic products were also obtained in hydroformylation of 1-buten-3-ol. In reaction of undec-1-ol and 2-allylphenol linear aldehydes were formed with the yield 69–87%. The hydroformylation of 3-buten-1-ol performed under “on water” conditions showed very good regioselectivity towards a linear aldehyde, 5-hydroxypentanal. Further cyclization of the aldehyde to tetrahydropyran-2-ol was observed.
- Alsalahi,Trzeciak
-
-
- Synthesis, structural characterization and catalysis of ruthenium(II) complexes based on 2,5-bis(2′-pyridyl)pyrrole ligand
-
Treatment of the 2,5-bis(2′-pyridyl)pyrrolato (PDP-) anion with {Ru(COD)Cl2}n in THF readily yielded [Ru(PDP)(COD)Cl] (1) in almost quantitative yield. Anion metathesis of 1 in organic solvent by NO3- and OTf- (OTf- = triflato) gave [Ru(PDP)(COD)(NO3)] (2) and [Ru(PDP)(COD)(OTf)] (3), and in aqueous solution by BF4- and PF6- afforded aqueous complexes [Ru(PDP)(COD)(H2O)](BF4) (4+·BF4-) and [Ru(PDP)(COD)(H2O)](PF6) (4+·PF6-), respectively. Treatment of 1 with PhICl2 in CH2Cl2 afforded 5 with halogenated pyrrole. These complexes exhibit similar structure, including one Ru(ii) atom, one 2,5-bis(2′-pyridyl)pyrrole and one monodentate anion or aqua ligand. Each Ru(ii) tightly binds to three adjacent coplanar sites of PDP- ligand to form a meridional configuration. Complex 1 with NaIO4 as the oxidant in EtOAc-CH3CN-H2O (ratio = 3 : 1 : 2) proved to be highly effective in the catalytic oxidation of olefins to carbonyl products.
- Zhong, Yi-Qing,Xiao, Hui-Qiong,Yi, Xiao-Yi
-
p. 18113 - 18119
(2016/11/25)
-
- TRANSFORMATION OF PEROXYACETAL INTERMEDIATE
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A method for transforming a compound of formula IIa: to a compound of formula III: is provided, wherein A is a C6-C10 alkene chain with at least one double bond, R1 is a C1-C10 alkyl, and R3 is an oxygen-containing functional group.
- -
-
Paragraph 00256; 00257
(2015/06/03)
-
- Regioselective Cleavage of Electron-Rich Double Bonds in Dienes to Carbonyl Compounds with [Fe(OTf)2(mix-BPBP)] and a Combination of H2O2 and NaIO4
-
A method for the regioselective transformation of dienes to carbonyl compounds has been developed. Electron-rich olefins react selectively to yield valuable aldehydes and ketones. The method is based on the catalyst [Fe(OTf)2(mix-BPBP)] with an oxidant combination of H2O2 (1.0 equiv.) and NaIO4 (1.5 equiv.); it uses mild conditions and short reaction times, and it outperforms other olefin cleavage methodologies. The combination of an Fe-based catalyst, [Fe(OTf)2(mix-BPBP)], and the oxidants H2O2 and NaIO4 can discriminate between electronically different double bonds and oxidatively cleave the electron-rich bond in dienes to yield aldehydes and ketones in a regioselective manner. The reaction requires mild conditions (0-50 C) and short reaction times (70 min).
- Spannring, Peter,Yazerski, Vital A.,Chen, Jianming,Otte, Matthias,Weckhuysen, Bert M.,Bruijnincx, Pieter C. A.,Klein Gebbink, Robertus J. M.
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p. 3462 - 3466
(2015/08/06)
-
- ACYCLIC ALKENES VIA OZONOLYSIS OF MULTI-UNSATURATED CYCLOALKENES
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A method of making a compound of formula (IIa) by selective ozonolysis of a compound of formula (I) is provided, wherein A is a C6-C10 alkene chain with at least one double bond, R1 is a C1-C10 alkyl, and R3 is an oxygen-containing functional group.
- -
-
Paragraph 00151
(2015/02/02)
-
- A highly efficient catalyst for selective oxidative scission of olefins to aldehydes: Abnormal-NHC-Ru(II) complex in oxidation chemistry
-
The utility and selectivity of the catalyst [Ru(COD)(L1)Br2] (1) bearing a fused π-conjugated imidazo[1,2-a][1,8]naphthyridine-based abnormal N-heterocyclic carbene ligand L1 is demonstrated toward selective oxidation of C=C bonds to aldehydes and C=C bonds to α-diketones in an EtOAc/CH3CN/H2O solvent mixture at room temperature using a wide range of substrates, including highly functionalized sugar- and amino acid-derived compounds.
- Daw, Prosenjit,Petakamsetty, Ramu,Sarbajna, Abir,Laha, Siladitya,Ramapanicker, Ramesh,Bera, Jitendra K.
-
supporting information
p. 13987 - 13990
(2015/01/08)
-
- Broad-spectrum catalysts for the ambient temperature anti-Markovnikov hydration of alkynes
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Anti-Markovnikov alkyne hydration provides a valuable route to aldehydes. Half-sandwich ruthenium complexes ligated by 5,5′-bis(trifluoromethyl)-2, 2′-bipyridine are remarkably active for this transformation. In the presence of 2 mol % metal, a wide range of functionalized aliphatic and aromatic alkynes are hydrated in high yield at ambient temperature. Alkyne hydration: Half-sandwich ruthenium complexes derived from 5,5′-bis(trifluoromethyl)- 2,2′-bipyridine show a high activity for the anti-Markovnikov hydration of terminal alkynes (see picture). A wide array of alkynes are efficiently hydrated to aldehydes using 2 mol % metal loadings at 25 °C within 8-24 h.
- Li, Le,Zeng, Mingshuo,Herzon, Seth B.
-
supporting information
p. 7892 - 7895
(2014/08/05)
-
- Structure, synthesis, and biological activity of a C-20 bisacetylenic alcohol from a marine sponge Callyspongia sp.
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An optically inactive C-20 bisacetylenic alcohol, (4E,16E)-icosa-4,16- diene-1,19-diyne-3,18-diol, was isolated from a marine sponge Callyspongia sp. as a result of screening of antilymphangiogenic agents from marine invertebrates. An optical resolution using chiral-phase HPLC gave each enantiomer, (-)-1 and (+)-2. Because the natural and synthetic enantiomers 1 and 2 showed different biological properties, we investigated the structure-activity relationships of bisacetylenic alcohols using 11 synthetic derivatives, and it is clarified that the essential structural unit for antiproliferative activity is the "1-yn-3-ol" on both termini and that there is a minimum chain length that connects the "1-yn-3-ol" moieties.
- Shirouzu, Takayuki,Watari, Kousuke,Ono, Mayumi,Koizumi, Keiichi,Saiki, Ikuo,Tanaka, Chiaki,Van Soest, Rob W. M.,Miyamoto, Tomofumi
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p. 1337 - 1342
(2013/08/23)
-
- 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
-
-
- On-column solvent-free oxidative cleavage reactions of vicinal diols by silica gel and paraperiodic acid: Application to in-situ sequential oxidation and Knoevenagel reactions
-
An on-column solvent-free oxidative cleavage reaction of vicinal diols by paraperiodic acid supported on silica gel at room temperature is described. The resulting pure carbonyl compounds are prepared in good to excellent yields with short reaction times. The cleavage reactions proceed under mild conditions, which avoids further cyclization reactions of the product dialdehydes. This method is also used for sequential oxidation and Knoevenagel reactions to prepare condensation products in good yields by using paraperiodic acid on a mixed bed of alumina and silica gel. The on-column solvent-free oxidative cleavage reaction of vicinal diols by paraperiodic acid supported on silica gel at room temperature is investigated. This approach is applied to an oxidation andKnoevenagel reaction sequence by using a mixed bed of alumina and silica gel to give condensation products in good yields. Copyright
- Dakdouki, Saada C.,Villemin, Didier,Bar, Nathalie
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supporting information; experimental part
p. 780 - 784
(2012/03/11)
-
- Kinetics and products of the reactions of OH radicals with cyclohexene, 1-methyl-1-cyclohexene, cis -cyclooctene, and cis -cyclodecene
-
Rate constants for the reactions of OH radicals with four C 6-C10 cycloalkenes have been measured at 297 ± 2 K using a relative rate technique. The rate constants (in units of 10 -11 cm3 molecule-1 s-1) were cyclohexene, 6.35 ± 0.12; cis-cyclooctene, 5.16 ± 0.15; cis-cyclodecene, 4.18 ± 0.06; and 1-methyl-1-cyclohexene, 9.81 ± 0.18, where the indicated errors are two least-squares standard deviations and do not include uncertainties in the rate constant for the reference compound 1,3,5-trimethylbenzene. In addition, a rate constant of (4.8 ± 1.3) × 10-11 cm3 molecule-1 s-1 was derived for the reaction of OH radicals with 1,6-hexanedial, relative to our measured rate constant for OH + cyclohexene. Analyses of products of the OH + cyclohexene, 1-methyl-1-cyclohexene, and cis-cyclooctene reactions by direct air sampling atmospheric pressure ionization mass spectrometry and/or by combined gas chromatography-mass spectrometry showed the presence of products attributed to cyclic 1,2-hydroxynitrates and the dicarbonyls 1,6-hexanedial, 6-oxo-heptanal, and 1,8-octanedial, respectively. These dicarbonyl products, which are those formed after decomposition of the intermediate cyclic 1,2-hydroxyalkoxy radicals, were quantified as their dioximes, with molar formation yields of 76 ± 10%, 82 ± 12%, and 84 ± 18% from the cyclohexene, 1-methyl-1-cyclohexene, and cis-cyclooctene reactions, respectively. Combined with literature data concerning 1,2-hydroxynitrate formation from OH + alkenes and the estimated fractions of the overall reactions proceeding by H-atom abstraction, 90 ± 12%, 95 ± 13% and 108 ± 20% of the products or reaction pathways from the OH radical-initiated reactions of cyclohexene, 1-methyl-1-cyclohexene, and cis-cyclooctene in the presence of NO are accounted for.
- Aschmann, Sara M.,Arey, Janet,Atkinson, Roger
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p. 9507 - 9515,9
(2012/12/12)
-
- Dihydroxylation of olefins catalyzed by zeolite-confined osmium(0) nanoclusters: An efficient and reusable method for the preparation of 1,2-cis-diols
-
Addressed herein is a novel, eco-friendly, recoverable, reusable and bottleable catalytic system developed for the dihydroxylation of various olefins yielding 1,2-cis-diols. In our protocol, zeolite-confined osmium(0) nanoclusters (zeolite-Os0) are used as reusable catalyst and H 2O2 served as a co-oxidant. Zeolite-Os0 are found to be highly efficient and selective catalysts for the dihydroxylation of a wide range olefins in an aqueous acetone mixture at room temperature. In all of the olefins surveyed, the catalytic dihydroxylation reaction proceeds smoothly and the corresponding 1,2-cis-diols are obtained in excellent chemical yield under the optimized conditions. The present heterogeneous catalyst system provides many advantages, such as being eco-friendly and industrially applicable over the traditional homogenous OsO4-NMO system for the dihydroxylation of olefins.
- Metin, Oender,Alp, Nurdan Alcan,Akbayrak, Serdar,Bier, Abdullah,Gueltekin, Mehmet Serdar,Oezkar, Saim,Bozkaya, Uur
-
supporting information; experimental part
p. 1488 - 1492
(2012/06/29)
-
- An original on-column oxidative cleavage of vicinal diols using alumina/potassium periodate: Application to sequential oxidation/Horner-Emmons reactions
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An unprecedented simple on-column solvent-free oxidative cleavage of vicinal diols in the solid phase using alumina/potassium metaperiodate is described herein. It permits preparation of the corresponding carbonyl compounds with high purity and good to excellent yields requiring only short reaction times. This methodology is then employed in on-column sequential oxidation/Horner-Emmons reactions for the preparation of selected stilbenes in good yields where both reaction and purification are integrated in a single unit or occur simultaneously permitting the rapid and easy preparation of small samples of pure stilbenes. The on-column oxidative cleavage of vicinal diols using alumina/potassium periodate is investigated. This approach is then applied to sequential oxidation/Horner-Emmons reactions for the simultaneous preparation and purification of stilbenes in good yields and requiring short reaction times.
- Dakdouki, Saada C.,Villemin, Didier,Bar, Nathalie
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experimental part
p. 4448 - 4454
(2011/10/01)
-
- An expedient procedure for the oxidative cleavage of olefinic bonds with PhI(OAc)2, NMO, and Catalytic OsO4
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(Figure Presented) PhI(OAc)2 In the presence of OsO4 (cat.) and 2,6-lutidine cleaves oleflnlc bonds to yield the corresponding carbonyl compounds, albeit, In some cases, with a-hydroxy ketones as byproduct. A more practical and clean protocol to effect oxidative cleavage of olefinic bonds involves NMO, OsO4 (cat.), 2,6-lutidine, and PhI(OAc) 2.
- Nicolaou,Adsool, Vikrant A.,Hale, Christopher R. H.
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supporting information; experimental part
p. 1552 - 1555
(2010/06/16)
-
- Highly regioselective hydroformylation of 1,5-hexadiene to linear dialdehyde catalyzed by rhodium complexes with tetraphosphorus ligands
-
Rhodium-catalyzed hydroformylation of 1,5-hexadiene to corresponding dialdehydes was investigated using tetraphosphorus ligands. These ligands showed a high regioselectivity for linear aldehydes (linear to branch ratio up to 98%) in very good yield (up to 87%). It was found that the introduction of the substituents at the ortho position of the biphenyl moiety has little effect on the regioselectivity and the electron-donating substituents retard the reaction somewhat.
- Yu, Shichao,Chie, Yu-ming,Zhang, Xiaowei,Dai, Liyan,Zhang, Xumu
-
experimental part
p. 5575 - 5577
(2011/02/22)
-
- An improved protocol for the oxidative cleavage of alkynes, alkenes, and diols with recyclable Ru/C
-
Efficient synthesis of carboxylic acids from alkynes; aldehydes from alkenes and diols employing Ru/C-based recyclable catalytic system is reported with good to excellent yields. Georg Thieme Verlag Stuttgart.
- Vijay Kumar,Prakash Reddy,Sridhar,Srinivas,Rama Rao
-
experimental part
p. 739 - 742
(2009/07/18)
-
- Synthesis and properties of gemini-type hydrocarbon-fluorocarbon hybrid surfactants
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Gemini-type hybrid surfactants with two fluorocarbon chains connected through a hydrocarbon spacer, F(CF2)m(CH2)2CH(OSO3Na)(CH2)nCH(OSO3Na)(CH2)2(CF2)mF [Fm(Hn)FmOS, m = 4, 6; n = 5, 6, 7, 8)], were synthesized and their surface chemical properties were examined with the aim to have highly functional and highly water-soluble fluorinated surfactants when compared with the conventional fluorinated surfactants. Comparisons of the surface chemical properties of the synthesized gemini-type hybrid surfactants with those of monounit-type hybrid surfactants, F(CF2)m(CH2)2CH(OSO3Na)(CH2)nH [FmEHnOS, m = 4, 6; n = 3, 5)], revealed that gemination causes a remarkable lowering (about 1/100) in cmc value while it produces little changes in Krafft point (below 0 °C) and surface tension at cmc (γcmc).
- Ohno, Aimi,Kushiyama, Atsunori,Kondo, Yukishige,Teranaka, Toshio,Yoshino, Norio
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experimental part
p. 577 - 582
(2009/04/03)
-
- PROCESS FOR THE SAFE OZONOLYSIS OF ORGANIC COMPOUNDS IN FLAMMABLE SOLVENTS
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An improved process for the safe ozonolysis of unsaturated, organic carbon compounds having one or more olefinic or aromatic double bonds in the molecule in flammable solvents for the preparation of mono- or biscarbonyl or hydroxy compounds, in which ozonolysis is carried out with the use of an ozone-carrying inert gas/O2 stream, in which the oxygen concentration in the inert gas/O2 stream is above the known limiting oxygen concentration of the homogeneous fuel/gas mixtures and below the safety-critical limiting oxygen concentration of the heterogeneous mixture of the liquid fuel and oxygen-containing gas which is dependent on the reaction conditions and at which ignition and flame propagation no longer take place.
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Page/Page column 22-23
(2008/12/06)
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- Activation of DMSO by phosphonitrilic chloride: An efficient method for oxidation of alcohols
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A variety of alcohols have been oxidized under mild conditions by a dimethylsulfoxide (DMSO)-chlorophosphazene complex. Sensitive groups such as silyl and tetrahydropyranyl (THP) ethers are stable under this condition. Copyright Taylor & Francis Group, LLC.
- Pandey, Sanjay K.,Bisai, Alakesh,Singh, Vinod K.
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p. 4099 - 4103
(2008/03/13)
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- Oxidative cleavage of alkenes catalyzed by a water/organic soluble manganese porphyrin complex
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Tetrakis(4-hydroxyphenyl)porphyrin [TPP-(OH)4] was modified with poly(ethylene glycol) chain as four side arms, such that this compound is soluble in both organic and water solutions. Complexation of this porphyrin with manganese metal ions resulted in the formation of MnCl-TPP-(PEO750)4. This complex proved to be an excellent catalyst for the oxidative cleavage of C{double bond, long}C bonds, yielding the corresponding carbonyl compounds with sodium periodate as an oxidant. Mechanistic pathway for this cleavage is discussed.
- Liu, Shiuh-Tzung,Reddy, K. Venugopal,Lai, Rung-Yi
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p. 1821 - 1825
(2007/10/03)
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- Catalytic oxidations of alcohols to carbonyl compounds by oxygen under solvent-free and transition-metal-free conditions
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A green catalytic oxidation of alcohols to carbonyl compounds by oxygen was developed by using catalytic amounts of [bis(acetoxy)iodo]benzene/TEMPO/ KNO2. In addition, the use of a catalytic amount of poly[4-(bis(acetoxy)iodo)]styrene led to yields (up to 99%) comparable to the non-supported hypervalent iodine reagent, while offering the advantage of an efficient recovery and the subsequent recycling of the hypervalent iodine reagent.
- Herrerías, Clara I.,Zhang, Tony Y.,Li, Chao-Jun
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- First stereoselective syntheses of (-)-siphonodiol and (-)- tetrahydrosiphonodiol, bioactive polyacetylenes from marine sponges
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The first stereoselective total syntheses of the bioactive marine polyacetylenes (-)-siphonodiol and (-)-tetrahydrosiphonodiol were achieved using highly convergent approaches based on optimized Cadiot-Chodkiewicz and sequential Sonogashira cross-coupling reactions.
- Lopez, Susana,Fernandez-Trillo, Francisco,Midon, Pilar,Castedo, Luis,Saa, Carlos
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p. 6346 - 6352
(2007/10/03)
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- Alkene cis-dihydroxylation by [(Me3tacn)(CF3CO 2)RuVIO2]CIO4 (Me3tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane): Structural characterization of [3 + 2] cycloadducts and kinetic studies
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cis-Dioxoruthenium(VI) complex [(Me3tacn)(CF3CO 2)RuVIO2]CIO4 (1, Me3tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) reacted with alkenes in aqueous tert-butyl alcohol to afford cis-1,2-diols in excellent yields under ambient conditions. When the reactions of 1 with alkenes were conducted in acetonitrile, oxidative C=C cleavage reaction prevailed giving carbonyl products in >90% yields without any cis-diol formation. The alkene cis-dihydroxylation and C=C cleavage reactions proceed via the formation of a [3 + 2] cycloadduct between 1 and alkenes, analogous to the related reactions with alkynes [Che et al. J. Am. Chem. Soc. 2000, 122, 11380], With cyclooctene and trans-β-methylstyrene as substrates, the Ru(III) cycloadducts [(Me3tacn)(CF 3CO2)RuIIIO(H)CH(CH2) 6HCO]CIO4 (4a) and [(Me3tacn)(CF 3CO2)RuIIIO(H)-PhCHCH(CH3)O]CIO 4 (4b) were isolated and structurally characterized by X-ray crystal analyses. The kinetics of the reactions of 1 with a series of p-substituted styrenes has been studied in acetonitrile by stopped-flow spectrophotometry. The second-order rate constants varied by 14-fold despite an overall span of 1.3 V for the one-electron oxidation potentials of alkenes. Secondary kinetic isotope effect (KIE) was observed for the oxidation of β-d2-styrene (kH/kD = 0.83 ± 0.04) and α-deuteriostyrene (kH/kD = 0.96 ± 0.03), which, together with the stereoselectivity of cis-alkene oxidation by 1, is in favor of a concerted mechanism.
- Yip, Wing-Ping,Yu, Wing-Yiu,Zhu, Nianyong,Che, Chi-Ming
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p. 14239 - 14249
(2007/10/03)
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- Supported ruthenium nanoparticle catalyst for cis -dihydroxylation and oxidative cleavage of alkenes
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The present invention relates to the use of nanosized metal particles (e.g., ruthenium) grafted on inert solid support for oxidation of alkenes. The supported metal catalyst can effect cis-dihydroxylation and oxidative cleavage of alkenes to give the respective cis-diols and carbonyl products.
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Page/Page column 4; 6
(2008/06/13)
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- Bis(pyridine)iodonium tetrafluoroborate (IPy2BF4): A versatile oxidizing reagent
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The use of bis(pyridine)iodonium tetrafluoroborate (IPy2BF 4) as an oxidizing agent towards different types of alcohols is reported. The observed reactivity involves different reaction pathways, as a function both of the structures of the starting materials and of the experimental conditions. Interestingly, the title iodine-containing compound is capable of a tuneable reaction with simple cycloalkanols, providing straight and selective access either to ω-iodocarbonyl compounds or to ketones, a previously unreported and chemoselective range of oxidation potential. Furthermore, appropriate conditions for the preparation of aldehydes and esters from primary alcohols by easily performed experimental procedures were also established. The β-scission reactions of cycloalkanols and the α-oxidation processes of primary, secondary and benzylic alcohols are discussed.
- Barluenga, Jose,Gonzalez-Bobes, Francisco,Murguia, Marcelo C.,Ananthoju, Sreenivasa R.,Gonzalez, Jose M.
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p. 4206 - 4213
(2007/10/03)
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- Hydroformylation of 1,5-hexadiene catalyzed by rhodium complexes in supercritical carbon dioxide and in toluene: Effects of fluorinated phosphane ligands and reaction conditions
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Rhodium-catalyzed hydroformylation of 1,5-hexadiene to dialdehydes was investigated in compressed CO2 and in toluene using different fluorinated phosphane compounds as ligands at a temperature of 60 °C. Product yields depend greatly on the ligand used and, of the ligands examined, tris[3,5-bis(trifluoromethyl)phenyl]phosphane is the most effective for the production of dialdehydes both in supercritical CO2 (scCO 2) and in toluene. The total yield of the dialdehydes passes through a minimum at about 9 MPa as the CO2 pressure is increased and increases appreciably as the H2 pressure in scCO2 increases. The effect of the syngas (H2/ CO) and H2 pressures on the reaction in scCO2 is different from that in toluene. It has been suggested that scCO2 promotes the hydroformylation reaction. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Fujita, Shin-Ichiro,Fujisawa, Shinya,Bhanage, Bhalchandra M.,Ikushima, Yutaka,Arai, Masahiko
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p. 2881 - 2887
(2007/10/03)
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- A general study of [(η5-Cp′)2Ti(η 2-Me3SiC2SiMe3)]-catalyzed hydroamination of terminal alkynes: Regioselective formation of Markovnikov and anti-Markovnikov products and mechanistic explanation (Cp′=C (5)H(5), C(5)H(4)Et, C(5)Me(5))
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A general study of the regioselective hydroamination of terminal alkynes in the presence of [(η5-Cp)2Ti(η2-Me 3SiC2SiMe3)] (1), [(η5-CpEt) 2Ti(η2-Me3SiC2SiMe3)] (CpEt= ethylcyclopentadienyl) (2), and [(η5-Cp*) 2Ti(η2-Me3SiC2SiMe3)] (Cp=pentamethylcyclopentadienyl) (3) is presented. While aliphatic amines give mainly the anti-Markovnikov products, anilines and aryl hydrazines yield the Markovnikov isomer as main products. Interestingly, using aliphatic amines such as n-butylamine and benzylamine the different catalysts lead to a significant change in the observed regioselectivity. Here, for the first time a highly selective switch from the Markovnikov to the anti-Markovnikov product is observed simply by changing the catalyst. Detailed theoretical calculations for the reaction of propyne with different substituted anilines and tert-butylamine in the presence of [(η5-C5H5)Ti(= NR)(NHR)] (R=4-C6H4X; X=H, F, Cl, CH3, 2,6-dimethylphenyl) reveal that the experimentally observed regioselectivity is determined by the relative stability of the corresponding π-complexes 10. While electrostatic stabilization favors the Markovnikov performance for aniline, the steric repulsive destabilization disfavors the Markovnikov performance for tert-butylamine.
- Tillack, Annegret,Jiao, Haijun,Castro, Ivette Garcia,Hartung, Christian G.,Beller, Matthias
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p. 2409 - 2420
(2007/10/03)
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- A general bifunctional catalyst for the anti-Markovnikov hydration of terminal alkynes to aldehydes gives enzyme-like rate and selectivity enhancements
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A new, bifunctional catalyst for anti-Markovnikov hydration of terminal alkynes to aldehydes (6) allows practical room-temperature hydration of alkyl-substituted alkynes. Other outstanding features include near-quantitative aldehyde yields from both alkyl- and aryl-substituted alkynes and wide functional group tolerance. The uncatalyzed rate of alkyne hydration is measured for the first time, showing the enzyme-like rate and selectivity enhancements of aldehyde formation by 6. For aldehyde formation, an uncatalyzed rate -10 mol h-1 means a half-life >600 000, years. The catalyzed rate is up to 23.8 mol (mol 6)-1 h-1 and 10 000:1 ratio in favor of aldehyde. Changes in rate and selectivity induced by 6 are thus >2.4 × 1011 and 300 000, respectively. Copyright
- Grotjahn, Douglas B.,Lev, Daniel A.
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p. 12232 - 12233
(2007/10/03)
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- Rhodium-tris(3,5-bis(trifluoromethyl)phenyl)phosphine catalyzed hydroformylation of dienes to dialdehydes in supercritical carbon dioxide with high activity
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Rhodium-catalyzed hydroformylation of 1,5-hexadiene and 1,7-octadiene to corresponding dialdehydes was investigated in compressed CO2 and in toluene using different fluorinated phosphine compounds as ligands. A rhodium complex using tris(3,5-bis(trifluoromethyl)phenyl)phosphine is highly effective in compressed CO2 for double hydroformylation of 1,5-hexadiene, whose TOF value is much larger than those reported so far. It has been shown that this ligand is effective also for the hydroformylation of 1,7-octadiene and scCO2 is a better solvent than a conventional organic solvent of toluene for the title reaction.
- Fujita, Shin-Ichiro,Fujisawa, Shinya,Bhanage, Bhalchandra M.,Arai, Masahiko
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p. 1307 - 1310
(2007/10/03)
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- Ruthenium nanoparticles supported on hydroxyapatite as an efficient and recyclable catalyst for cis-dihydroxylation and oxidative cleavage of alkenes
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Impregnation of hydroxyapatite with colloidal ruthenium results in the formation of a catalyst that effects cis-dihydroxylation and oxidative cleavage of alkenes to their respective cis-1,2-diols and carbonyl products in good to excellent yields (see scheme). The supported ruthenium catalyst can be easily recycled and reused for consecutive reaction runs without significant deterioration of the catalytic activities. R1, R2 = H, alkyl, aryl.
- Ho, Chi-Ming,Yu, Wing-Yiu,Che, Chi-Ming
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p. 3303 - 3307
(2007/10/03)
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- IN-SITU DECOMPOSITION OF PEROXIDES DURING THE OZONOLYSIS OF ALKENES
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The invention relates to a method for carrying out the in-situ decomposition of peroxides during the ozonolysis of optionally substituted alkenes in order to form the corresponding aldehydes or ketones. According to the method, the optionally substituted alkenes are reacted in water, a C1-C4 carboxylic ester, a C1-C4 carboxylic acid, a water/C1-C4 carboxylic acid mixture, a C1-C6 alcohol or in a water/C1-C6 alcohol mixture at a temperature ranging from -30 °C to +50 °C, in the presence of a heterogeneous inorganic catalyst selected from the group consisting of iridium, manganese, cobalt, silver, gold, palladium, platinum or ruthenium, which is applied to a supporting material selected from the group consisting of calcium carbonate, coal, titanium dioxide, magnesium oxide, zirconium oxide, silica or aluminum oxide or in the presence of a homogeneous inorganic catalyst selected from the group consisting of transition metal catalysts while simultaneously decomposing peroxides with ozone. Afterwards, the catalyst is separated out from the reaction mixture once the ozonolysis is complete thus obtaining corresponding aldehydes and ketones.
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- Scope, kinetics, and mechanistic aspects of aerobic oxidations catalyzed by ruthenium supported on alumina
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The Ru/Al2O3 catalyst was prepared by modification of the preparation of Ru(OH)3·nH2O. The present Ru/Al 2O3 catalyst has high catalytic activities for the oxidations of activated, nonactivated, and heterocyclic alcohols, diols, and amines at 1 atm of molecular oxygen. Furthermore, the catalyst could be reused seven times without a loss of catalytic activity and selectivity for the oxidation of benzyl alcohol. A catalytic reaction mechanism involving a ruthenium alcoholate species and β-hydride elimination from the alcoholate has been proposed. The reaction rate has a first-order dependence on the amount of catalyst, a fractional order on the concentration of benzyl alcohol, and a zero order on the pressure of molecular oxygen. These results and kinetic isotope effects indicate that β-elimination from the ruthenium alcoholate species is a rate-determining step.
- Yamaguchi, Kazuya,Mizuno, Noritaka
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p. 4353 - 4361
(2007/10/03)
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- Process for producing aldehydes
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A process for producing an aldehyde of the invention allows a 1,2-diol (vic-diol) to react with oxygen in the presence of a ruthenium catalyst supported on a carrier to oxidatively cleave a bond between two carbon atoms, where hydroxyl groups are combined with the carbon atoms, to thereby yield a corresponding aldehyde. The carrier includes, for example, an activated carbon. As a catalytic component to be supported on the carrier, dichlorotris(triphenylphosphine)ruthenium(II), and other organic ruthenium complexes, for example, can be used. The invention can efficiently produce a corresponding aldehyde by oxidative cleavage of a 1,2-diol with oxygen.
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- Bis-desulfoglucosinolates: A new class of bolaforms
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Bis-desulfoglucosinolates 14-18 bearing D-gluco, lacto, malto and cellobio saccharidic moieties were synthesized in two steps from the corresponding protected 1-thio-β-D-glycopyranoses 5, 8, 10 and 12 and bis-hydroximoyl chlorides 3a and 4a derived from 1,8-octanedial (1) and 1,12-dodecanedial (2). Fully deprotections of the intermediate O-acetylated derivatives 6, 7, 9, 11 and 13 were realized either using Zemplen method or methanol/triethylamine/water mixture, the choice of the conditions being dependent on the solubility in methanol of the fully and partially acetylated derivatives.
- Lafont, Dominique,Chevalier, Yves,Grumel, Valerie,Cassel, Stephanie,Rollin, Patrick
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p. 2919 - 2930
(2007/10/03)
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- An alternative to the Swern oxidation
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A variety of alcohols have been oxidized under mild conditions by the DMSO-Ph3P·X2 complexes. The reaction does not produce any Pummerer product. A mechanism for the reaction is proposed.
- Bisai, Alakesh,Chandrasekhar,Singh, Vinod K.
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p. 8355 - 8357
(2007/10/03)
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- Aerobic Oxidation of Vicinal Diols Catalyzed by an Anderson-Type Polyoxometalate, [IMo6O24]5-
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An Anderson-type polyoxometalate, [IVIIMo6O24]5-, has been used as a catalyst for the aerobic oxidation at 80°C of vicinal diols (glycols). This is the first report on the use of such a polyoxometalate as an oxi
- Khenkin, Alexander M.,Neumann, Ronny
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p. 1017 - 1021
(2007/10/03)
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- Oxidation of α,ω-diols using the Dess - Martin periodinane
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Depending on the length of the carbon tether, α,ω-diols either afford cyclic acetoxy acetals or dialdehydes upon treatment with the Dess - Martin periodinane.
- Roels,Metz
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p. 789 - 790
(2007/10/03)
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- Ruthenium-catalyzed oxidative cleavage of olefins to aldehydes
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Three oxidation protocols have been developed to cleave olefins to carbonyl compounds with ruthenium trichloride as catalyst (3.5 mol %). These methods convert olefins that are not fully substituted to aldehydes rather than carboxylic acids. While aryl olefins were cleaved to aromatic aldehydes in excellent yields by using the system of RuCl3-Oxone-NaHCO3 in CH3CN-H2O (1.5:1), aliphatic olefins were converted into alkyl aldehydes with RuCl3-NaIO4 in 1,2-dichloroethane-H2O (1:1) in good to excellent yields. It is noteworthy that terminal aliphatic olefins were cleaved to the corresponding aldehydes in excellent yields by using RuCl3-NaIO4 in CH3CN-H2O (6:1).
- Yang,Zhang
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p. 4814 - 4818
(2007/10/03)
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- Macrocyclic ketones as fragrance materials and methods for making same
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Novel macrocyclic diene ketone compounds useful as fragrance materials are described having the following general formula (I): where R1, R2, R3and R4are each either a hydrogen atom or a C1to C4alkyl, a is the integer 1 or 2 and b is an integer in a range from 1 to 6. Novel pathways are described for synthesizing these macrocyclic diene ketones, as well as saturated and mono-unsaturated macrocyclic ketones having the following general formula (IV): where R1, R2, R3and R4are each independently a hydrogen atom or a C1to C4alkyl, a is the integer 1 or 2 and b is an integer in a range from 1 to 6.
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- Selective and rapid oxidation of primary, allylic and benzylic alcohols to the corresponding carbonyl compounds with NaNO2-acetic anhydride under mild and solvent-free conditions
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Various primary, benzylic and allylic alcohols undergo selective and rapid oxidation to the corresponding carbonyl compounds using NaNO2-acetic anhydride as a novel oxidant under mild and solvent free conditions. The Royal Society of Chemistry 2000.
- Bandgar, Babasaheb P.,Sadavarte, Vaibhav S.,Uppalla, Lavkumar S.
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p. 3559 - 3560
(2007/10/03)
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