- SELECTIVE TRIMERIZATION OF ALIPHATIC ALDEHYDES CATALYZED BY POLYNUCLEAR CARBONYLFERRATES
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Aliphatic aldehydes undergo a catalytic trimerization to give 1,3-diol monoesters upon treatment with Fe3(CO)12 in pyridine or with Fe3(CO)12-pyridine N-oxide in benzene.Polynuclear carbonylferrates serve as catalyst for this transformation.
- Ito, Keiji,Kamiyama, Nobuhiro,Nakanishi, Saburo,Otsuji, Yoshio
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- Silica gel-supported TEMPO with adsorbed NOx for selective oxidation of alcohols under mild conditions
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A column padding silica gel was used to support 2,2,6,6- tetramethylpiperdine-1-oxyl (TEMPO) and to adsorb NOx to provide an oxidant system for the selective oxidation of alcohols. A wide range of alcohols were oxidized to the corresponding aldehydes and ketones with high selectivities and conversions using this heterogeneous catalyst under mild conditions.
- Zhang, Hua,Fu, Luoling,Zhong, Hongmin
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- Vapor-phase aldolization of n-butyraldehyde to 2-ethyl-2-hexenal over solid-base catalysts
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Vapor-phase aldol condensation of n-butyraldehyde to 2-ethyl-2-hexenal was studied at 1 atm and 150～ 300°C in a fixed-bed, integral-flow reactor by using NaX, KX, γ-Al2O3 and Na/NaOH/γ-Al2O3 catalysts. Ion exchange of NaX zeolite with potassium acetate solution results in a decrease of crystallinity and apparent lowering of surface area, whereas the basic strength is enhanced. Treatment of γ-Al2O3 with NaOH and Na causes a large decrease of the surface area but strong enhancement of the catalyst basicity. The catalytic activity on the basis of unit surface area is in the order Na/NaOH/γ-Al2O3 > KXU > KXW > NaX>γ-Al2O3, in accordance with the relative catalyst basic strength. The molar ratio of trimeric to dimeric products increases with increasing the reaction temperature and the catalyst basic strength except for Na/NaOH/γ-Al2O3. Very high selectivity of 2-ethyl-2-hexenal (>98.5%) was observed for reactions over NaX zeolite at 150°C. Based on the FT-IR and the catalytic results, the reaction paths are proposed as follows: self-aldol condensation of n-butyraldehyde, followed by dehydration produces 2-ethyl-2-hexenal, which then reacts with n-butyraldehyde and successively dehydrates to 2,4-diethyl-2,4-octadienal and 1,3,5-triethylbenzene. For the reaction over NaX, the calculated Arrhenius frequency factor and activation energy are 314 mol/g-h and 32.6 kJ/mol, respectively.
- Zhu, Wei-De,Ko, An-Nan
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- Iron/ABNO-Catalyzed Aerobic Oxidation of Alcohols to Aldehydes and Ketones under Ambient Atmosphere
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We report a new Fe(NO3)3·9H2O/9-azabicyclo[3.3.1]nonan-N-oxyl catalyst system that enables efficient aerobic oxidation of a broad range of primary and secondary alcohols to the corresponding aldehydes and ketones at room temperature with ambient air as the oxidant. The catalyst system exhibits excellent activity and selectivity for primary aliphatic alcohol oxidation. This procedure can also be scaled up. Kinetic analysis demonstrates that C-H bond cleavage is the rate-determining step and that cationic species are involved in the reaction.
- Wang, Lianyue,Shang, SenSen,Li, Guosong,Ren, Lanhui,Lv, Ying,Gao, Shuang
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- One-pot synthesis of C8 aldehydes/alcohols from propylene using eco-friendly hydrotalcite supported HRhCO(PPh3)3 catalyst
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A multi-functional catalyst [HF/HT] containing a rhodium complex, HRh(CO)(PPh3)3 [HF] and a solid base, hydrotalcite Mg 1-xAlx(OH2)x+(CO 32-)x/n·mH2O [HT], synthesized by impregnation of [HF] onto the surface of [HT], was investigated for the one-pot synthesis of C8 aldol derivatives (aldehydes or alcohols) from propylene. The catalyst was found to be efficient to carry out hydroformylation, aldol condensation and hydrogenation reactions in one pot. The catalytic activity of [HF/HT(X)] was studied in detail as functions of Mg/Al molar ratio (X) of [HT], amount of [HF] complex and [HT], and reaction temperature. The selectivity for 2-ethylhexanal was observed to increase upon increasing X and amount of [HT]. The highest selectivity for 2-ethylhexanol was observed for [HT] Mg/Al molar ratio of 3.5 at 250°C. The kinetic profiles of the various products obtained were in agreement with the reaction pathway proposed to understand the role of the [HF/HT] catalyst on the formation of C8 aldol derivatives. Thermal stability of the [HF/HT] catalyst system was also investigated. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Sharma, Sumeet K.,Srivastava, Vivek K.,Shukla, Ram S.,Parikh, Parimal A.,Jasra, Raksh V.
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- Enamines from terminal epoxides and hindered lithium amides
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A new reactivity mode of lithium amides with epoxides leads to hindered enamines. The reaction of some of these enamines with unactivated primary and secondary alkyl halides is described, which expands the range of electrophiles that one can use in the synthesis of mono-alkylated aldehydes. Copyright
- Hodgson, David M.,Bray, Christopher D.,Kindon, Nicholas D.
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- Practical and versatile oxidation of alcohol using novel Na2WO4-H2O2 system under neutral conditions
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This paper presents a novel Na2WO4-H2O2 oxidation system. The oxidation of alcohol to ketone or aldehyde was carried out by using N,N-dimethylacetamide, hydrogen peroxide, and a catalytic amount of disodium tungstate dihydrate under neutral conditions. This method is very simple, practical for large-scale manufacturing, and applicable to a variety of substrates including an acid-sensitive substrate. Disodium tetraperoxotungstate dihydrate (Na2[W(O2)4]·2H2O) was isolated from a mixture of N,N-dimethylacetamide, hydrogen peroxide, and disodium tungstate dihydrate, and a proposal reaction mechanism is discussed in this paper.
- Hida, Takemasa,Nogusa, Hideo
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- Continuous catalytic "one-pot" multi-step synthesis of 2-ethylhexanal from crotonaldehyde
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2-Ethylhexanal is synthesized directly from crotonaldehyde over a bifunctional acidic resin-supported palladium catalyst via hydrogenation and aldol condensation in supercritical CO2. The Royal Society of Chemistry.
- Seki, Tsunetake,Grunwaldt, Jan-Dierk,Baiker, Alfons
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- Synthesis of renewable plasticizer alcohols by formal anti-Markovnikov hydration of terminal branched chain alkenes via a borane-free oxidation/reduction sequence
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An efficient method for the formal anti-Markovnikov hydration of 1,1-disubstituted alkenes has been developed. The utility of the process has been demonstrated by conversion of bio-derived butene oligomers into primary alcohols through initial oxidation to vicinal acetoxy-alcohols, diols, or diacetates, followed by selective dehydration/tautomerization of the diols, and hydrogenation of the intermediary aldehydes. This approach allows for the isolation of important industrial plasticizer alcohols from a renewable source. In a broader context, this pathway, which can be conducted with sustainable, conventional reagents under mild conditions, represents a unique alternative to hydroboration for a challenging subset of hindered olefins.
- Harvey, Benjamin G.,Meylemans, Heather A.,Quintana, Roxanne L.
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- 4-OH-TEMPO/TCQ/TBN/HCl: A Metal-Free Catalytic System for Aerobic Oxidation of Alcohols under Mild Conditions
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A green and economical catalyst system, 4-OH-TEMPO/TCQ/TBN/HCl, for the aerobic oxidation of a broad range of primary and secondary alcohols to the corresponding carbonyl compounds has been developed. These reactions proceed without transition-metals under mild conditions with excellent yields. A green and economical catalyst system, 4-OH-TEMPO/TCQ/TBN/HCl, for the aerobic oxidation of a broad range of primary and secondary alcohols to the corresponding carbonyl compounds has been developed. These reactions proceed without transition-metals under mild conditions with excellent yields.
- Dong, Yanli,Zhao, Xiaomei,Liu, Renhua
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- Oxidation of Primary Alcohols over Hydrous Zirconium(IV) Oxide
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The oxidation of primary alcohols with quinone or benzophenone was carried out by catalysis with hydrous zirconium(IV) oxide in both batch and flow reaction systems.As a result, it was elucidated that a lot of primary alcohols can be efficiently oxidized over hydrous zirconium(IV) oxide.
- Kuno, Hideyuki,Shibagaki, Makoto,Takahashi, Kyoko,Matsushita, Hajime
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- Novel synthesis of manganese and vanadium mixed oxide (V2O 5/OMS-2) as an efficient and selective catalyst for the oxidation of alcohols in liquid phase
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This work reports the synthesis and characterization of mixed oxide vanadium-manganese V2O5/K-OMS-2 at various V/Mn molar ratios and prepared by the impregnation method. Characterization of these new composite materials was made by elemental analysis, BET, XRD, FT-IR, SEM and TEM techniques. Results of these analyses showed that vanadium impregnated samples contained mixed phases of cryptomelane and crystalline V2O 5 species. Oxidation of various alcohols was studied in the liquid phase over the V2O5/K-OMS-2 catalyst using tert-butyl hydroperoxide (TBHP) and H2O2 as the oxidant. Activity of the V2O5/K-OMS-2 samples was increased considerably with respect to K-OMS-2 catalyst due to the interaction of manganese oxide and V 2O5. The kinetic of benzyl alcohol oxidation using excess TBHP over V2O5/K-OMS-2 catalyst was investigated at different temperatures and a pseudo-first order reaction was determined with respect to benzyl alcohol. The effects of reaction time, oxidant/alcohol molar ratio, reaction temperature, solvents, catalyst recycling potential and leaching were investigated.
- Mahdavi, Vahid,Soleimani, Shima
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- Environmentally friendly approach to α-acyloxy carboxamides: Via a chemoenzymatic cascade
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A new, green route for the synthesis of α-acyloxy carboxamides from an alcohol, a carboxylic acid and an isocyanide was developed. The reaction comprises the aerobic oxidation of an alcohol to the corresponding aldehyde, catalyzed by the Trametes versicolor laccase/TEMPO system, followed by a one pot Passerini reaction in an aqueous surfactant medium. The influence of different types of surfactants on the reaction efficiency was investigated. The best results were obtained by employing dioctadecyldimethylammonium bromide (DODAB), a known vesicle-forming cationic surfactant. Importantly, apart from the metalloenzyme used, the described procedure toward α-acyloxy carboxamides is metal-free and does not require hazardous organic solvents, what makes it environmentally friendly.
- Paprocki, Daniel,Koszelewski, Dominik,Zad?o, Anna,Walde, Peter,Ostaszewski, Ryszard
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- Hydrogenation of but-2-enal over supported Au/ZnO catalysts
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The hydrogenation of but-2-enal over supported Au catalysts is discussed, together with a detailed characterisation study using X-ray diffraction, infrared spectroscopy and transmission electron microscopy. Au/ZnO catalysts are found to be selective for t
- Bailie,Abdullah,Anderson,Rochester,Richardson,Hodge,Zhang,Burrows,Kiely,Hutchings
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- Effects of carboxylic acid adsorbates on CO adsorption and crotonaldehyde hydrogenation over Cu/Al2O3 catalyst
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A study was performed to determine how the adsorption of carboxylic acids (formic or acetic acid) would influence the surface character of alumina-supported Cu catalysts. IR spectra of adsorbed CO were used to probe the effect of the carboxylic acids on exposed Cu sites. The hydrogenation of crotonaldehyde was used as a test-reaction for catalytic behavior since it showed that surface modification of oxide-supported Cu catalysts with heterocyclic dopants may result in enhancements in selectivity to crotyl alcohol. Formic acid adsorption on reduced Cu0 sites generated adsorbed bidentate formate which blocked CO adsorption at many sites, induced cationic character at the remaining available sites, and partially poisoned hydrogenation reactions. Modification of the surface poisoned C=O hydrogenation more than C=C hydrogenation and promoted butanal as the main hydrogenation product. Desorption of formate by ″flashing″ at high temperature led to a partly reconstructed surface which yielded higher catalytic activities than an unmodified surface before formic acid treatment. The effects of acetic acid adsorption were similar to those for formic acid except that attempts at desorption of the modifier led to carbonaceous residues which partially poisoned CO adsorption and catalytic activity.
- Rochester,Bailie,Richardson,Abdullah,Hutchings,Anderson
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- Zn-Al LDH nanostructures pillared by Fe substituted Keggin type polyoxometalate: Synthesis, characterization and catalytic effect in green oxidation of alcohols
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Zn-Al layered double hydroxides pillared by Fe(III) substituted Keggin type polyoxometalate, [Zn2Al(OH)6](NO3)0.6(PW11FeO39)0.1·mH2O (LDH-PWFe), was synthesized by anion exchange method. The synthesized compound was characterized using various techniques such as FTIR, XRF, XRD, TGA, and BET. The resulting LDH-PWFe was assessed as catalyst in the green oxidation of alcohols with aqueous H2O2 as the oxidant. Results showed that, LDH-PWFe is an efficient catalyst for the oxidation of alcohols into corresponding aldehydes with good to excellent conversions and excellent selectivity. Recovery and reusability experiments of the catalyst demonstrated that, it could be recycled and reused at least five times without manifest loss of activity and selectivity.
- Hasannia, Saeed,Yadollahi, Bahram
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- Oxidation of alcohol by lipopathic Cr(VI): A mechanistic study
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The oxidation kinetics of various aliphatic primary and secondary alcohols having varied hydrocarbon chain length were studied using cetyltrimethylammonium dichromate (CTADC) in dichloromethane (DCM) in the presence of acetic acid and in the presence of a cationic surfactant. The rate of the reaction is highly sensitive to the change in [CTADC], [alcohol], [acid], [surfactant], polarity of the solvents, and reaction temperature. A Michaelis-Menten type kinetics was observed with respect to substrate. The chemical nature of the intermediate and the reaction mechanism were proposed on the basis of (i) observed rate constant dependencies on the reactants, that is, fractional order with respect to alcohol and acid and a negative order with respect to oxidant, (ii) high negative entropy change, (iii) inverse solvent kinetic isotope effect, k(H 2O)/k(D2O) = 0.76, (iv) low primary kinetic isotope effect, kH/kD = 2.81, and (v) the kobs dependencies on solvent polarity parameters. The observed experimental data suggested the self-aggregation of CTADC giving rise to a reverse micellar system akin to an enzymatic environment, and the proposed mechanism involves the following: (i) formation of a complex between alcohol and the protonated dichromate in a rapid equilibrium, equilibrium constant K = 5.13 (±0.07) dm3 mol-1, and (ii) rate determining decomposition (k 2 = (7.6 ± 0.7) × 10-3 s-1) of the ester intermediate to the corresponding carbonyl compound. The effect of [surfactant] on the rate constant and the correlation of solvent parameters with the rate constants support the contribution of hydrophobic environment to the reaction mechanism.
- Patel, Sabita,Mishra
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- Dehydrogenation of primary aliphatic alcohols to aldehydes over Cu-Ni bimetallic catalysts
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The catalytic conversion of non-activated primary aliphatic alcohols to aldehydes is a challenge, and monometallic Cu-based catalysts loaded on different supports have often been used for these reactions. Cu-Ni/γ-Al2O3 bimetallic catalysts were prepared and used for anaerobic dehydrogenation of 3,3-dimethyl-1-butanol to 3,3-dimethyl-1-butanal. These catalysts exhibited higher activity than Cu/γ-Al2O3 under the same reaction conditions, and a wide range of primary aliphatic alcohols were efficiently converted to the corresponding aldehydes over Cu-Ni/γ-Al2O3 under mild conditions.
- Lu, Tianliang,Du, Zhongtian,Liu, Junxia,Chen, Chen,Xu, Jie
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- A Kinetic Study of 2-Ethyl-1-hexanol Oxidation by Dichromate Using Clay-Supported 1-Butyl 4-aza-1-azonia Bicyclo[2.2.2]octane Chloride as the Phase-Transfer Catalyst
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Selective oxidation of primary alcohols to aldehydes is a long-standing problem of organic chemistry (Bueler, C. A.; Pearson, D. E. Survey of Organic Synthesis; Wiley-Interscience: New York, 1977; Vol. 2, p 480; House, H. O. Modern Synthetic Reactions, 2nd. ed.; W. A. Benjamin: Menlo Park, California, 1972; p 257; Epstein, W. W.; Sweet, F. W. Chem. Rev. 1967, 67, 247; Landini, D. ; Montanari, F.; Rolla, F. Synthesis 1979, 134). The use of potassium dichromate as a synthetically useful oxidizing agent is reported for the oxidation of an industrially important lipophilic alcohol, employing modified clay as the phase-transfer catalyst. The phase-transfer catalysis results in nearly complete oxidation of the 2-ethylhexanol in 40 min at room temperature, with high selectivity to the 2-ethylhexanal, compared to 48 h in its absence. Kinetic studies show the reaction occurs via transfer of Cr2O 72- into the organic phase. The emphasis will be on simplicity of the condition as a preparative organic method, selectivity with regard to over-oxidation, efficiency, and mildness of conditions.
- Ghiaci,Kalbasi,Sedaghat
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- Preparation and catalytic performance of NiO-MnO2/Nb2O5-TiO2 for one-step synthesis of 2-ethylhexanol from n-butyraldehyde
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One-pot synthesis of 2-ethylhexanol(2EHO) from n-butyraldehyde is of commercialimportance. The promotion of 2EHO selectivity requires suppressing direct hydrogenation of n-butyraldehyde. In this work, a series of NiO-MOx/Nb2O5-TiO2 catalysts were prepared and utilized by means of reduction-in-reaction technique, aiming at delaying the formation of metal sites and suppressing the direct hydrogenation. NiO-MnO2/Nb2O5-TiO2 with a Ni/Mn mass ratio of 10 and NiO-MnO2 loading of 14.3 wt% shows the best catalytic performance; 2-EHO selectivity could reach 90.0% at a complete conversion of n-butyraldehyde. Furthermore the catalyst could be used for four times without a substantial change in its catalytic performance.
- An, Hualiang,Li, Sibo,Wang, Yanji,Zhang, Jiaxun,Zhao, Xinqiang
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- One-pot synthesis of 2-alkyl cycloketones on bifunctional Pd/ZrO2 catalyst
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2-Alkyl cycloketones are essential chemicals and intermediates for synthetic perfumes and pesticides, which are conventionally produced by multistep process including aldol condensation, separation and hydrogenation. In present work, a batch one-pot cascade approach using aldehydes and cycloketones as the raw materials, and a bifunctional Pd/ZrO2 catalyst was developed for the synthesis of 2-alkyl cycloketones, e.g., cyclohexanone and cycloheptanone. Very high aldehydes (except for paraldehyde with large steric hindrance) conversion and high yields for 2-alkyl cycloketones (e.g., 99 % of conversion for n-butanal and 76 wt.% of yield for 2-butyl cyclohexanone) were obtained at mild temperature of 140 °C. After 10 cycles of reuse, Pd/ZrO2 catalyst showed slight deactivation (ca. 5 % conversion and 10 % yield losses), due to the coke on the catalyst. However, the performance of the catalyst was completely recovered after an oxidative regeneration.
- Xue, Weiyang,Gu, Bin,Wu, Huiling,Liu, Mengyang,He, Songbo,Li, Jingmei,Rong, Xin,Sun, Chenglin
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- HIGHLY EFFICIENT METHOD FOR PRODUCING SATURATED HOMOETHER FROM UNSATURATED CARBONYL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for efficiently producing a saturated homoether from an unsaturated carbonyl compound. SOLUTION: The method for producing an unsaturated homoether uses an unsaturated carbonyl compound and hydrogen as a raw material, uses a catalyst comprising a metal supported on an acidic catalyst carrier and performs at least once a pressure reduction operation so that a differential pressure from a reaction pressure is 0.01 MPa or more. In the method, the metal of the catalyst is, for example, palladium and the carrier of the catalyst is alumina, silica, silica-alumina or the like. The unsaturated carbonyl compound serving as a raw material is 2-butenal, 2-ethyl-2-hexenal, 2-ethyl-2-butenal, 2-hexenal or the like and the produced saturated homoether is dibutyl ether, bis(2-ethylhexyl)ether, bis(2-ethylbutyl)ether, dihexyl ether or the like. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0041; 0047-0048
(2020/07/16)
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- Practical catalytic nitration directly with commercial nitric acid for the preparation of aliphatic nitroesters
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To pursue a sustainable and efficient approach for aliphatic nitroester preparation from alcohol, europium-triflate-catalyzed nitration, which directly uses commercial nitric acid, has been successfully developed. Gram scalability with operational ease showed its practicability.
- An, Jichao,He, Pan,Li, Wenhao,Liu, Peipei,Si, Mengyuan,Yang, Bo,Yang, Guanyu
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p. 6612 - 6616
(2020/09/21)
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- SATURATED HOMOETHER MANUFACTURING METHOD FROM UNSATURATED CARBONYL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for manufacturing saturated homoether from an unsaturated carboxyl compound at good efficiency. SOLUTION: There is provided a manufacturing method of saturated homoether using an unsaturated carboxyl compound and hydrogen as raw materials, and a catalyst in which a metal is carried on an acidic catalyst carrier. The metal of the catalyst is for example palladium, and the carrier of the catalyst is alumina, silica, silica-alumina, or the like. The unsaturated carbonyl compound as the raw material is 2-butenal, 2-ethyl-2-hexenal, 2-ethyl-2-butenal, 2-hexenal, and manufactured saturated homoether is dibuthylether, bis(2-ethylhexyl)ether, bis(2-ethylbuty)ether, dihexylether, or the like. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPO&INPIT
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Paragraph 0039; 0044
(2020/05/14)
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- Nickel-Catalyzed Selective Reduction of Carboxylic Acids to Aldehydes
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The direct reduction of carboxylic acids to aldehydes is a fundamental transformation in organic synthesis. The combination of an air-stable Ni precatalyst, dimethyl dicarbonate as an activator, and silane reductant effects this reduction for a wide variety of substrates, including pharmaceutically relevant structures, in good yields and with no overreduction to alcohols. Moreover, this methodology is scalable, allows access to deuterated aldehydes, and is also compatible with one-pot utilization of the aldehyde products.
- Iosub, Andrei V.,Morav?ík, ?tefan,Wallentin, Carl-Johan,Bergman, Joakim
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supporting information
p. 7804 - 7808
(2019/10/14)
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- AROMA CHEMICAL COMPOSITIONS CONTAINING 3,5-DIETHYL-2-PROPYL-TETRAHYDROPYRAN AND/OR UNSATURATED DERIVATIVES THEREOF
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The present invention relates to aroma chemical compositions containing 3,5-diethyl-2-propyl-tetrahydropyran, a 3,5-diethyl-2-propyl-dihydropyran or a 3,5-diethyl-2-propyl-pyran, a mixture of such compounds, a stereoisomer of one of these compounds, or a mixture of stereoisomers of one or more of these compounds. The invention further relates to a method for preparing such compounds, stereoisomers or mixtures thereof, to the composition obtainable by this method, to the use of such compounds as an aroma chemicalor for modifying the scent character of a fragranced composition; and to a method for preparing a fragranced composition or for modifying the scent character of a fragranced composition using said compounds. Moreover, the invention relates to 3,5-diethyl-2-propyl-tetrahydropyran, to its stereoisomers and to mixtures of these stereoisomers.
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(2019/04/27)
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- Highly efficient and practical aerobic oxidation of alcohols by inorganic-ligand supported copper catalysis
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The oxidation of alcohols to aldehydes or ketones is a highly relevant conversion for the pharmaceutical and fine-chemical industries, and for biomass conversion, and is commonly performed using stoichiometric amounts of highly hazardous oxidants. The aerobic oxidation of alcohols with transition metal complex catalysts previously required complicated organic ligands and/or nitroxyl radicals as co-catalysts. Herein, we report an efficient and eco-friendly method to promote the aerobic oxidation of alcohols using an inorganic-ligand supported copper catalyst 1, (NH4)4[CuMo6O18(OH)6], with O2 (1 atm) as the sole oxidant. Catalyst 1 is synthesized directly from cheap and commonly available (NH4)6Mo7O24·4H2O and CuSO4, which consists of a pure inorganic framework built from a central CuII core supported by six MoVIO6 inorganic scaffolds. The copper catalyst 1 exhibits excellent selectivity and activity towards a wide range of substrates in the catalytic oxidation of alcohols, and can avoid the use of toxic oxidants, nitroxyl radicals, and potentially air/moisture sensitive and complicated organic ligands that are not commercially available. Owing to its robust inorganic framework, catalyst 1 shows good stability and reusability, and the catalytic oxidation of alcohols with catalyst 1 could be readily scaled up to gram scale with little loss of catalytic activity, demonstrating great potential of the inorganic-ligand supported Cu catalysts in catalytic chemical transformations.
- Wei, Zheyu,Ru, Shi,Zhao, Qixin,Yu, Han,Zhang, Gang,Wei, Yongge
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supporting information
p. 4069 - 4075
(2019/08/07)
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- Catalytic performance of Ni/Γ-Al2O3 for hydrogenation of 2-ethyl-2-hexenal
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The effect of reaction conditions on the catalytic performance of Ni/γ-Al2O3 was investigated and the result showed that Ni/γ-Al2O3 showed excellent catalytic activity. However, the catalytic performance of the recovered Ni/γ-Al2O3 catalyst declined dramatically. The fresh and the recovered catalysts were comparatively analyzed by means of XRD, XPS and FT-IR techniques. The result demonstrated that the main reason for the activity decline of the recovered Ni/γ-Al2O3 catalyst is that the surface Ni has been reoxidized to NiO. After calcination and reduction, the recovered Ni/γ-Al2O3 catalyst could be reused four times without a significant decrease in its catalytic performance.
- Zhao, Lili,Wang, Yi,An, Hualiang,Zhao, Xinqiang,Wang, Yanji
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- Transfer-hydrogenation process
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A transfer-hydrogenation process for preparing a carbonyl compound and an alcohol compound comprises the steps of (a) contacting a first carbonyl compound with a first alcohol compound in the presence of a transfer-hydrogenation catalyst in a first reaction zone at conditions effective to form a second carbonyl compound from the first alcohol compound and a second alcohol compound from the first carbonyl compound, and (b) removing the second carbonyl compound from the first reaction zone during step (a). The first carbonyl compound is a saturated aldehyde or ketone, or an α,β-unsaturated aldehyde or ketone. The first alcohol compound is a primary or secondary alcohol. The second alcohol compound is α,β-saturated. The transfer-hydrogenation catalyst includes a Group 8 to 11 metal. This process is useful for preparing and higher value alcohols, such as butanol or 2-ethylhexanol, from the corresponding carbonyl compounds by engaging lower alcohol (C2-C4) feedstocks instead of hydrogen (H2).
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Page/Page column 19; 20; 22-25
(2018/06/19)
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- PROCESS FOR PRODUCING 2-ETHYLHEXANAL HELPING TO IMPROVE YIELD
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A process for producing 2-ethylhexanal involves performing reaction using a reaction tank equipped with a gas-introducing mixer having extracting, exhausting, and stirring functions in the presence of a palladium on carbon catalyst having a carbon carrier with lower impurity content and higher specific surface area for hydrogenation, and introducing hydrogen gas evenly into reaction liquid; resulted in that the process minimizes operational pressure for hydrogenation and increases a yield of 2-ethylhexanal at least up to 98.0%.
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Paragraph 0066; 0067; 0068; 0069; 0070; 0071; 0072-0089
(2018/03/25)
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- CONVERSION OF ALCOHOLS TO LINEAR AND BRANCHED FUNCTIONALIZED ALKANES
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Embodiments herein concerns the eco-friendly conversion of simple alcohols to linear or branched functionalized alkanes, by integrated catalysis. The alcohols are firstlyoxidized either chemically or enzymatically to the corresponding aldehydes or ketones, followed by aldol condensations using a catalyst to give the corresponding enals or enones. The enals or enones are subsequently and selectively hydrogenated using a recyclable heterogeneous metal catalyst, organocatalyst or an enzyme to provide linear or branched functionalized alkanes with an aldehyde, keto- or alcohol functionality. The process is also iterative and can be further extended by repeating the above integrated catalysis for producing long-chain functionalized alkanes from simple alcohols.
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(2018/03/09)
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- Renewable plasticizer alcohols from olefin oligomers and methods for making the same
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An efficient, low-temperature process to convert well-defined olefin oligomers, particularly butene oligomers to branched chain alcohols suitable for use as precursors to plasticizers commonly used in industry, and more specifically, the olefin feedstocks can be conveniently and renewably produced from short chain alcohols.
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- Solventless, selective and catalytic oxidation of primary, secondary and benzylic alcohols by a Merrifield resin supported molybdenum(vi) complex with H2O2 as an oxidant
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Here, we have described the synthesis, characterization and catalytic activity of a dioxo-molybdenum(vi) complex supported on functionalized Merrifield resin (MR-SB-Mo). The functionalization of Merrifield resin (MR) was achieved in two-steps viz. carbonylation (MR-C) and Schiff base formation (MR-SB). The compounds, MR-C, MR-SB and MR-SB-Mo, were characterized at each step of the synthesis by elemental, SEM, EDX, thermal, BET and different spectroscopic analysis. The catalyst, MR-SB-Mo, efficiently and selectively oxidized a wide variety of alcohols to aldehydes or ketones using 30% H2O2 as an oxidant with reasonably good TOF (660 h-1 in case of benzyl alcohol). The catalyst acted heterogeneously under solventless reaction conditions and did not lead to over oxidized products under optimized conditions. The catalyst afforded regeneration and can be reused for at least five reaction cycles without loss of efficiency and product selectivity. A reaction mechanism for the catalytic activity of MR-SB-Mo was proposed and a probable reactive intermediate species isolated.
- Boruah, Jeena Jyoti,Das, Siva Prasad
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p. 34491 - 34504
(2018/10/21)
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- Efficient aerobic oxidation of alcohols catalyzed by NiGa hydrotalcites in the absence of any additives
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The aerobic oxidation of alcohol catalyzed by NiGa hydrotalcites in the absence of any additives has been studied in detail. The research results revealed that the surface basicity significantly affected the catalytic performance. Moreover, the Br?nsted OH basic site on Ni-containing hydrotalcites was suggested to be the key active site and accelerated the oxidation. The catalytic system had good tolerance for various alcohols, and an excellent selectivity of aldehyde could be obtained for the oxidation of primary alcohol. A probable non-radical reaction path for the transformation has been proposed according to the catalytic results, isotope labelling experiments and Hammett experiments.
- Sun, Fuan,Zhou, Jiacheng,Zhou, Weiyou,Pan, Jiugao,Qian, Junfeng,He, Mingyang,Chen, Qun
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p. 4029 - 4035
(2018/03/21)
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- Highly practical and efficient preparation of aldehydes and ketones from aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst
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Herein, we divulge an efficient protocol for aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst, (NH4)5[IMo6O24]. The catalyst system is compatible with a wide range of groups and exhibits high selectivity, and shows excellent stability and reusability, thus serving as a potentially greener alternative to the classical transformations.
- Zhang, Mengqi,Zhai, Yongyan,Ru, Shi,Zang, Dejin,Han, Sheng,Yu, Han,Wei, Yongge
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supporting information
p. 10164 - 10167
(2018/09/13)
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- Microwave-assisted isomerizations of epoxides to allylic alcohols
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The present work reports a study on the isomerization reactions of several alkyl epoxides to the corresponding allylic alcohols or bicyclic alcohols under microwave irradiation. The reaction occurred in the presence of lithium diisopropylamide as a base and different experimental conditions in terms of solvent, amount of the base, times and temperatures. The traditional heating with an oil-bath and the use of alternative organometallic bases, as the Lochmann-Schlosser bases, have been furthermore compared with the microwave heating. The results obtained show that the use of microwave irradiations on promoting the isomerization of epoxides gives access to a series of synthetically useful products, among which allylic alcohols and bicyclic alcohols, depending on the starting substrate.
- Consiglio, Gabriella Barozzino,Mordini, Alessandro
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p. 447 - 454
(2018/05/22)
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- SINGLE-STEP CONVERSION OF N-BUTYRALDEHYDE TO 2-ETHYLHEXANAL
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Disclosed is a method of making and using a titania supported palladium catalyst for the single step synthesis of 2-ethylhexanal from a feed of n-butyraldehyde. This titania supported palladium catalyst demonstrates high n-butyraldehyde conversion but also produces 2-ethylhexanal in an appreciable yield with maintained activity between runs. This method provides a single step synthesis of 2-ethylhexanal from n-butyraldehyde with a catalyst that can be regenerated that provides cleaner downstream separations relative to the traditional caustic route.
- -
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Paragraph 00130; 00133
(2017/08/21)
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- Acetaldehyde as an ethanol derived bio-building block: An alternative to Guerbet chemistry
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In this work, we describe a highly selective poly-aldol condensation of acetaldehyde, which can readily be obtained via dehydrogenation of ethanol. The process operates under mild temperatures (100°C or less) using commercially available catalysts and exhibits excellent total carbon yield of C4+ products with good selectivity for C6 products. The products derived from the reactions described herein are shown to be candidate drop-in fuel replacements for compression ignition engines and precursors to valuable chemicals.
- Moore, Cameron M.,Staples, Orion,Jenkins, Rhodri W.,Brooks, Ty J.,Semelsberger, Troy A.,Sutton, Andrew D.
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supporting information
p. 169 - 174
(2017/01/24)
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- Method for preparing aldehyde ketone by efficiently catalyzing molecular oxygen to oxidize alcohol by taking hydrotalcite-like material as catalyst
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The invention belongs to the technical field of liquid-phase catalytic oxidation and provides a method for preparing aldehyde ketone by efficiently catalyzing molecular oxygen to oxidize alcohol by taking a hydrotalcite-like material as a catalyst. The catalyst can be expressed as A-NixM-LDHs (A=OH, CO3, CH3COO and PO4; M is Ga or In; the ratio of Ni to M is (2-4) to 1). The method is characterized by preparing aldoketones compounds by carrying out aerobic oxidation reaction on alcohol under mild condition without adding additives in the presence of the catalyst. The hydrotalcite-like material can be synthesized in quantity and can be recycled; the method has the advantages of high selectivity and yield of aldehyde ketone, mild reaction condition, low cost and easiness in realizing industrialization.
- -
-
Paragraph 0036; 0037; 0038; 0039; 0042
(2017/09/29)
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- Green method for preparation of aldehyde or ketone by iron catalyzed alcohol oxidation
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The invention provides a green method for preparation of aldehyde or ketone by iron catalyzed alcohol oxidation. The method adopts a common iron salt as the catalyst, uses an oxynitride as the cocatalyst, can realize oxidation of various alcohols in a non-halogen solvent and under open air room temperature conditions, and especially can achieve oxidation of high selectivity non-active fatty primary alcohol. The catalytic system uses a cheap and easily available, non-toxic and high activity iron catalyst system, and uses economical, safe and green air as the oxidant. The reaction temperature can be set at room temperature condition. The catalytic system has few components, and additional adding of a ligand or alkali compound is unnecessary. The reaction is easy in operation, and especially can realize oxidation of non-active fatty primary alcohol into aldehyde or ketone efficiently. The method provided by the invention has very mild requirements for reaction conditions, and has good research and industrial application prospects.
- -
-
Paragraph 0028; 0029; 0030
(2017/08/29)
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- Visible-Light-Induced Efficient Selective Oxidation of Nonactivated Alcohols over {001}-Faceted TiO2 with Molecular Oxygen
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In the presence of molecular oxygen, a {001}-faceted nanocrystalline anatase TiO2 catalyst enabled the selective oxidation of nonactivated aliphatic alcohols to the corresponding aldehydes or ketones under visible light. The reaction shows excellent conversion and selectivity towards the formation of the carbonyl products without over-oxidation to the corresponding carboxylic acids. The exceptional reactivity of the catalyst is possibly due to the absorption of visible light originating from a stronger interaction of alcohol with the {001} facet, which facilitates the modification of the band structure of TiO2, thus facilitating the photogenerated hole transfer and subsequent oxidation processes. The experimental results have also been corroborated by first-principles quantum chemical DFT calculations.
- Vadakkekara, Raji,Biswas, Abul Kalam,Sahoo, Tapan,Pal, Provas,Ganguly, Bishwajit,Ghosh, Subhash Chandra,Panda, Asit Baran
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supporting information
p. 3084 - 3089
(2016/11/13)
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- A 2-heptanone synthetic method
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The invention discloses a chemical synthetic method, specifically a method for synthesizing 2-heptanone by using acetone and butyraldehyde as raw materials. According to the invention, acetone and butyraldehyde which used as raw materials undergo a cross aldol condensation reaction under catalysis of solid base, and reaction products further undergo dehydration and catalytic hydrogenation so as to prepare 2-heptanone. The invention has advantages as follows: technological process is shortened by the technology; generation of an acid-containing waste liquid is avoided; generation of by-products is minimized; investment in equipment is reduced; and production costs of the product are decreased.
- -
-
Paragraph 0045-0047
(2017/01/26)
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- Direct synthesis of 2-ethylhexanol via n-butanal aldol condensation-hydrogenation reaction integration over a Ni/Ce-Al2O3 bifunctional catalyst
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Direct synthesis of 2-ethylhexanol from n-butanal via the reaction integration of n-butanal self-condensation with 2-ethyl-2-hexenal hydrogenation is of crucial interest for industrial production of 2-ethylhexanol. Furthermore, as an important and versatile chemical, n-butanol can be produced simultaneously by reaction integration. In the present work, several bifunctional catalysts based on γ-Al2O3 were prepared by the impregnation method and were characterized by means of H2-TPR, XRD, TEM and H2-TPD, and their catalytic performance for direct synthesis of 2-ethylhexanol from n-butanal was investigated. The results showed that Co/Al2O3 had a low activity for hydrogenation and Cu/Al2O3 had a high selectivity for the hydrogenation of the C=O group while a Ru/Al2O3 catalyst only favored the hydrogenation of n-butanal to n-butanol. Among them, the Ni/Al2O3 catalyst showed the best catalytic performance and the yield of 2-ethylhexanol was the highest (49.4%). Ce-modified Ni/Al2O3 enhanced the competitiveness of aldol condensation versus hydrogenation of n-butanal and improved the selectivity of 2-ethylhexanol; the yield of 2-ethylhexanol rose to 57.8%. Then the influence of preparation conditions on the catalytic performance of Ni/Ce-Al2O3 was investigated and the suitable preparation conditions were obtained as follows: Ni loading = 10%, calcined at 550 °C for 5 h, and reduced at 570 °C for 4 h. The effect of reaction conditions on the integration reaction catalyzed by Ni/Ce-Al2O3 was investigated and the suitable reaction conditions were obtained as follows: weight percentage of Ni/Ce-Al2O3 = 15%, reaction temperature = 170 °C, reaction pressure = 4.0 MPa and reaction time = 8 h. Under the above reaction conditions, the yield of 2-ethylhexanol attained 66.9% and that of n-butanol was 18.9%. In addition, the components existing in the integration reaction system were identified by GC-MS analysis, and the main by-products were n-butyl butyrate, 2-ethylhexyl butyrate, n-butyric acid, etc. Based on the analysis of the reaction system, a reaction network for the direct synthesis of 2-ethylhexanol from n-butanal was proposed. Finally, an evaluation of the reusability of Ni/Ce-Al2O3 showed that the recovered Ni/Ce-Al2O3 catalyst lost its catalytic activity for the hydrogenation of the C=O group. The main reason for deactivation was that Ni species were covered by the flaky boehmite γ-AlO(OH) formed from the hydration of γ-Al2O3 in the reaction process.
- Liang, Ning,Zhang, Xiaolong,An, Hualiang,Zhao, Xinqiang,Wang, Yanji
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p. 2959 - 2972
(2015/05/27)
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- A TEMPO-free copper-catalyzed aerobic oxidation of alcohols
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The copper-catalyzed aerobic oxidation of primary and secondary alcohols without an external N-oxide co-oxidant is described. The catalyst system is composed of a Cu/diamine complex inspired by the enzyme tyrosinase, along with dimethylaminopyridine (DMAP) or N-methylimidazole (NMI). The Cu catalyst system works without 2,2,6,6-tetramethyl-l-piperidinoxyl (TEMPO) at ambient pressure and temperature, and displays activity for un-activated secondary alcohols, which remain a challenging substrate for catalytic aerobic systems. Our work underscores the importance of finding alternative mechanistic pathways for alcohol oxidation, which complement Cu/TEMPO systems, and demonstrate, in this case, a preference for the oxidation of activated secondary over primary alcohols.
- Xu, Boran,Lumb, Jean-Philip,Arndtsen, Bruce A.
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supporting information
p. 4208 - 4211
(2015/04/14)
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- Green oxidation of alcohols in water by a polyoxometalate nano capsule as catalyst
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In this work a water soluble polyoxometalate nano capsule, HxPMo12O40 ? H4Mo72Fe30(CH3COO)15O254, with high stability was evaluated for the oxidation of various alcohols into the corresponding aldehydes and ketones by hydrogen peroxide. This environmentally and economically valuable catalyst allowed for using water as solvent and has not required any organic solvents. In the presence of very low amounts of catalyst high to excellent yields and selectivity were obtained.
- Nikbakht, Elham,Yadollahi, Bahram,Farsani, Mostafa Riahi
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p. 135 - 138
(2015/03/30)
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- Hollow Ni-Co-B amorphous alloy nanospheres: Facile fabrication via vesicle-assisted chemical reduction and their enhanced catalytic performances
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In this paper, we develop a simple vesicle-assisted chemical reduction approach for synthesizing hollow Ni-Co-B nanospheres. With various characterization techniques, the resulting Ni-Co-B nanospheres are identified as amorphous alloys with a hollow chamber. Coexistence of NiII and CoII species plays a significant role in fabricating hollow nanospheric structures, because only solid nanoparticles can be obtained in the presence of a mono-metallic precursor. During liquid-phase hydrogenation of 2-ethyl-2-hexenaldehyde, hollow Ni-Co-B catalyst displays significant bi-site catalysis from bimetals and delivers much greater activity as well as better selectivity than associated with the dense Ni-Co-B catalyst. Additionally, this catalyst is also easily handled in liquid-phase reactions due to its lower density and magnetic property. The material design concept presented in this work opens a new avenue for the development of hollow non-noble metallic nanospheres and will draw more attention in the foreseeable future.
- Wei,Zhao,Peng,Zhang,Bian,Li,Li
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supporting information
p. 19253 - 19259
(2015/02/05)
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- 4-Benzamido-TEMPO catalyzed oxidation of a broad range of alcohols to the carbonyl compounds with NaBrO3 under mild conditions
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4-Benzamido-TEMPO catalyzed oxidation system for conversion of a wide range of alcohols to the aldehydes or ketones with NaBrO3 under room temperature conditions has been developed. The credible, operationally convenient and economical, and condition mild oxidation protocol is particularly of interest in laboratory and in fine chemicals manufacture. 4-Benzamido-TEMPO catalyzed oxidation system for conversion of a wide range of alcohols to the aldehydes or ketones with NaBrO3 as oxidant under room temperature conditions has been developed. Copyright
- Shen, Jiaxuan,Sun, Jiangkai,Qin, Shuangshuang,Chu, Changhu,Liu, Renhua
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p. 405 - 409
(2014/06/10)
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- One-step synthesis of nitriles by the dehydrogenation-amination of fatty primary alcohols over Cu/m-ZrO2
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An effective method for one-step synthesis of nitriles employing C 2-C8 fatty primary alcohols and ammonia over 5%Cu/m-ZrO2 has been found. The conversion of alcohols and selectivity of nitriles obtained are > 96 and > 87 wt.%, respectively, and are obviously influenced by the C2-substitution rather than the chain length of fatty primary alcohols. Cu/m-ZrO2 was characterized by XRD, H 2-TPR, CO2-TPD and NH3-TPD. It is revealed that a substantial amount of Cu species over m-ZrO2 is in highly dispersed CuO. A plausible mechanism is proposed and supported by different experiments, and aldehyde generation is an important step in the reaction mechanism.
- Hu, Yunfeng,Jin, Shuhan,Zhang, Zhichao,Zhang, Likun,Deng, Jun,Zhang, Hongsheng
-
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- Polyoxometalate-based metal-organic frameworks as catalysts for the selective oxidation of alcohols in micellar systems
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A series of nanosized metal-organic frameworks (MOFs) encapsulating different polyoxometalates (POMs) including H3PW4O 12, H5PMo12O40, H 5PVMo10O40, H5PV2Mo 10O40, and H5PV3Mo 10O40 was synthesized and used in the selective oxidation of alcohols. The catalyst with a uniform size and morphology offered easy accessibility between substrates and catalyst. At the same time, the MOF ensured that the POM was encapsulated, which could dramatically prevent the assembly of the catalyst. Furthermore, the catalyst showed clear chemoselectivity, which was related to the size or accessibility of the substrates for surface pores. With cetyltrimethyl ammonium bromide aqueous solution as solvent, both improved reaction efficiency and simple recycling of the catalytic system were achieved to afford a green oxidation process. It's what's inside that counts: A series of polyoxometalate (POM)-based metal-organic frameworks (MOFs) was prepared and used in the selective oxidation of alcohols. Experiments with these MOFs were carried out in cetyltrimethyl ammonium bromide micellar solutions. With various alcohols as substrates, better to excellent conversion and selectivity were presented (see figure). Thus a green and efficient process was obtained. Copyright
- Zhu, Jie,Shen, Meng-Nan,Zhao, Xue-Jing,Wang, Peng-Cheng,Lu, Ming
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p. 872 - 878
(2014/07/08)
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- One-step synthesis of nitriles by the dehydrogenation-amination of fatty primary alcohols over Cu/m-ZrO2
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An effective method for one-step synthesis of nitriles employing C2-C8 fatty primary alcohols and ammonia over 5%Cu/m-ZrO2 has been found. The conversion of alcohols and selectivity of nitriles obtained are > 96 and > 87 wt.%, respectively, and are obviously influenced by the C2-substitution rather than the chain length of fatty primary alcohols. Cu/m-ZrO2 was characterized by XRD, H2-TPR, CO2-TPD and NH3-TPD. It is revealed that a substantial amount of Cu species over m-ZrO2 is in highly dispersed CuO. A plausible mechanism is proposed and supported by different experiments, and aldehyde generation is an important step in the reaction mechanism.
- Hu, Yunfeng,Jin, Shuhan,Zhang, Zhichao,Zhang, Likun,Deng, Jun,Zhang, Hongsheng
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- METHODS FOR PRODUCING FUELS, GASOLINE ADDITIVES, AND LUBRICANTS
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The present disclosure generally relates to the production of fuels, gasoline additives, and/or lubricants, and precursors thereof. The compounds used to produce the fuels, gasoline additives, and/or lubricants, and precursors thereof may be derived from biomass. The fuels, gasoline additives, and/or lubricants, and precursors thereof may be produced by a combination of intermolecular and/or intramolecular aldol condensation reactions, Guerbet reactions, hydrogenation reactions, and/or oligomerization reactions.
- -
-
Paragraph 0172
(2015/01/06)
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- Highly dispersed Pd on Co-B amorphous alloy: Facile synthesis via galvanic replacement reaction and synergetic effect between Pd and Co
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In this paper, uniform Co-B amorphous alloy nanospheres with an average particle size of 50 nm were synthesized by chemical reduction of cobalt ion with borohydride in aqueous solution containing Bu4PBr and KCl. Then, Pd was introduced into this system by galvanic replacement reaction (GRR) between Co and Na2PdCl4. Pd/Co-B catalysts with different Pd content could be obtained via adjusting the amount of Na2PdCl 4 in reaction mixture. The crystal structure, morphology, and surface electronic state of as-prepared catalysts were characterized by XRD, TEM, XPS, and H2-TPD. During the liquid-phase hydrogenation of 2-ethyl-2-hexenaldehyde, the as-prepared Pd/Co-B catalysts exhibited extremely active and more selectivity to 2-ethyl-1-hexanol than the monometallic Pd and Co-B amorphous alloy, showing potential application in industry. The enhanced performances could be attributed to the highly dispersed Pd on the surface of Co-B prepared by GRR and the synergetic effect between Pd and Co.
- Li, Hui,Ma, Jinqiang,Xu, Liang,Xu, Lei,Wang, Hao,Xu, Sen,Li, Hexing,Xie, Songhai
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p. 985 - 992
(2013/07/25)
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- Aerobic oxidative coupling of alcohols and amines over Au-Pd/resin in water: Au/Pd molar ratios switch the reaction pathways to amides or imines
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A facile switch of the reaction pathways of aerobic oxidative coupling of alcohols and amines from amidation to imination was realized for the first time by tuning the Au/Pd ratios in ion-exchange resin supported Au-Pd alloy catalysts (Au-Pd/resin). Amides were obtained with high yields on Au6Pd/resin while imines were obtained over AuPd4/resin. Various alcohols and amines underwent oxidative coupling smoothly in water to afford the desired products with good to excellent yields. Further investigation on the reaction mechanism suggested the synergistic effect between Au and Pd determined the adsorption strength of the aldehyde intermediate, which in turn dictated the reaction pathways. That is, on Au-rich alloys (e.g., Au6Pd) absorbed aldehyde species was formed, followed by further oxidation to yield amides, while on Pd-rich alloys (e.g., AuPd4), free aldehyde was generated, which then underwent condensation with amines to produce imines. The discovery might provide avenues to develop new efficient catalysts for the green synthesis of special chemicals.
- Zhang, Leilei,Wang, Wentao,Wang, Aiqin,Cui, Yitao,Yang, Xiaofeng,Huang, Yanqiang,Liu, Xiaoyan,Liu, Wengang,Son, Jin-Young,Oji, Hiroshi,Zhang, Tao
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supporting information
p. 2680 - 2684
(2013/10/08)
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- C-alkylation of chiral tropane- and homotropane-derived enamines
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The synthesis and alkylation of chiral, nonracemic tropane- and homotropane-derived enamines is examined as an approach to enantioenriched α-alkylated aldehydes. The two bicyclic N auxiliaries, which differ by a single methylene group, give opposite senses of asymmetric induction on alkylation with EtI and provide modestly enantioenriched 2-ethylhexanal (following hydrolysis of the alkylated iminium). The observed stereoselectivity is supported by density functional studies of ethylation for both enamines.
- Hodgson, David M.,Charlton, Andrew,Paton, Robert S.,Thompson, Amber L.
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p. 1508 - 1518
(2013/05/09)
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- Ugi four-component reaction of alcohols: Stoichiometric and catalytic oxidation/MCR sequences
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A new, simple, and efficient procedure for the one-pot Ugi four-component reaction of alcohols instead of aldehydes is described. Using a stoichiometric amount of IBX or only 1-2% of sodium 2-iodobenzenesulfonate in the presence of Oxone, a wide range of primary alcohols were oxidized to the aldehyde that were directly engaged in the Ugi four-component reaction to afford α-acetamidoamides in good to excellent yields.
- Drouet, Fleur,Masson, Géraldine,Zhu, Jieping
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supporting information
p. 2854 - 2857
(2013/07/26)
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- OXIDATION OF PRIMARY ALIPHATIC ALCOHOLS WITH A NOBLE METAL POLYOXOMETALATE COMPLEX
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A process of oxidizing primary alcohols to their corresponding aldehydes is disclosed. The process is effected in the presence of noble metal polyoxometalate complexes. A novel process for preparing noble metal polyoxometalate complexes, and novel noble metal polyoxometalate complexes are also disclosed.
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Page/Page column 10
(2012/08/08)
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- Coordination studies on supramolecular chiral ligands and application in asymmetric hydroformylation
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In this study we introduce a series of monodentate pyridine-based ligands for which the phosphorus coordination mode to rhodium can be controlled by the binding of ZnII-templates to the pyridyl group. A series of monodentate phosphoroamidite and phosphite ligands have been prepared and studied under hydroformylation conditions by in situ high-pressure NMR and IR techniques. These studies reveal the exclusive formation of rhodium hydride complexes in which the phosphorus atom of the ligand resides in an axial position, trans to the hydride, but only after addition of Zn II-template. In the absence of these templates the usual mono-coordinated rhodium hydrido complexes are formed, with the phosphorus ligated in the equatorial plane, cis to the hydride. The catalytic performance of these complexes is evaluated in asymmetric hydroformylation of unfunctionalised internal alkenes in which the supramolecular change is reflected in higher activity and selectivity.
- Bellini, Rosalba,Reek, Joost N. H.
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supporting information; experimental part
p. 7091 - 7099
(2012/07/27)
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- Amidation of aldehydes and alcohols through α-iminonitriles and a sequential oxidative three-component strecker reaction/thio-michael addition/alumina-promoted hydrolysis process to access β-mercaptoamides from aldehydes, amines, and thiols
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Mild and general alumina-promoted hydrolysis conditions for converting α-iminonitriles into carboxamides have been developed. In combination with the oxidative three-component Strecker reaction, the one-pot direct amidation of aldehydes and alcohols is reported. Subsequently, an Yb(OTf) 3-catalyzed Michael addition of thiols to α,β-unsaturated α-iminonitriles is reported for the synthesis of β-mercapto-α- iminonitriles. The successful integration of an oxidative Strecker reaction, thio-Michael addition, and neutral-alumina-promoted hydrolysis of β-mercapto-α-iminonitriles into a three-component one-pot process allowed us to develop the direct conversion of amines, aldehydes, and thiols into β-mercaptoamides. All of these procedures were applicable to aromatic and aliphatic amines and aldehydes. First direct: The direct amidation reactions of aldehydes and alcohols were performed in combination with the oxidative three-component synthesis of α-iminonitriles. In addition, β-mercaptoamides were readily accessed from α,β-unsaturated aldehydes, amines, and thiols by a sequential process that involved a three-component Strecker reaction, Yb(OTf)3-catalyzed thio-Michael addition, and hydrolysis of the resulting β-mercapto-α-iminonitriles (see scheme). Copyright
- Gualtierotti, Jean-Baptiste,Schumacher, Xavier,Fontaine, Patrice,Masson, Géraldine,Wang, Qian,Zhu, Jieping
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supporting information
p. 14812 - 14819
(2013/01/15)
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- Conversion of biomass-derived butanal into gasoline-range branched hydrocarbon over Pd-supported catalysts
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For production of gasoline-range branched hydrocarbon from butanal, Pd catalysts supported on different metal oxides were applied. Among the prepared catalysts, Pd/ZrO2 showed the complete butanal conversion with the formation of C7-to-C9 branched hydrocarbon (75% yield). Additionally, the ratios of O/C and straight-chain to branched hydrocarbon (n-C/br-C) were found to be 0.005 and 0.17, respectively. This indicates that an adequate combination of Pd dispersion and amphoteric ZrO2 character promoted hydrodeoxygenation, C-C coupling and isomerization reactions. Consequently, both Pd dispersion and acid-base properties of supports are suggested to play a pivotal role in producing gasoline-range hydrocarbon at a high yield.
- Kim, Sung Min,Lee, Mi Eun,Choi, Jae-Wook,Suh, Dong Jin,Suh, Young-Woong
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scheme or table
p. 108 - 113
(2012/03/10)
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- Green and chemoselective oxidation of alcohols with hydrogen peroxide: A comparative study on Co(II) and Co(III) activity toward oxidation of alcohols
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Two new cobalt (II) and cobalt (III) complexes of a terpyridine based ligand, (4′-(2-thienyl)-2,2′;6′,2″-terpyridine (L)), were synthesized. Each complex has two units of the tridentate ligand. The complexes were fully characterized by spectroscopic methods as well as CHN analysis. Moreover, their solid state structures were determined by single crystal X-ray diffraction. The cobaltous complex has the formula [Co(L) 2](NO3)2·2CH3OH·H 2O (1), whereas the cobaltic complex shows the formula [Co(L) 2](NO3)3·2CH3OH (2). Both complexes were tested as homogenous catalysts for the oxidation of a variety of aliphatic and aromatic alcohols utilizing aqueous hydrogen peroxide in water media. The Co(II) complex showed more activity in comparison with its isostructural Co(III) species. The results show that the aromatic alcohols were oxidized with higher conversions and selectivity compared to the aliphatic substrates, possibly due to their conjugation systems which thermodynamically stabilized the carbonyl products.
- Nemati Kharat, Ali,Bakhoda, Abolghasem,Tamaddoni Jahromi, Bahareh
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scheme or table
p. 2768 - 2775
(2011/12/13)
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