- Preparation and Degradation of Rhodium and Iridium Diolefin Catalysts for the Acceptorless and Base-Free Dehydrogenation of Secondary Alcohols
-
Rhodium and iridium diolefin catalysts for the acceptorless and base-free dehydrogenation of secondary alcohols have been prepared, and their degradation has been investigated, during the study of the reactivity of the dimers [M(μ-Cl)(I4-C8H12)]2 (M = Rh (1), Ir (2)) and [M(μ-OH)(I4-C8H12)]2 (M = Rh (3), Ir (4)) with 1,3-bis(6′-methyl-2′-pyridylimino)isoindoline (HBMePHI). Complex 1 reacts with HBMePHI, in dichloromethane, to afford equilibrium mixtures of 1, the mononuclear derivative RhCl(I4-C8H12){κ1-Npy-(HBMePHI)} (5), and the binuclear species [RhCl(I4-C8H12)]2{μ-Npy,Npy-(HBMePHI)} (6). Under the same conditions, complex 2 affords the iridium counterparts IrCl(I4-C8H12){κ1-Npy-(HBMePHI)} (7) and [IrCl(I4-C8H12)]2{μ-Npy,Npy-(HBMePHI)} (8). In contrast to chloride, one of the hydroxide groups of 3 and 4 promotes the deprotonation of HBMePHI to give [M(I4-C8H12)]2(μ-OH){μ-Npy,Niso-(BMePHI)} (M = Rh (9), Ir (10)), which are efficient precatalysts for the acceptorless and base-free dehydrogenation of secondary alcohols. In the presence of KOtBu, the [BMePHI]- ligand undergoes three different degradations: Alcoholysis of an exocyclic isoindoline-N double bond, alcoholysis of a pyridyl-N bond, and opening of the five-membered ring of the isoindoline core.
- Buil, Mariá L.,Collado, Alba,Esteruelas, Miguel A.,G? mez-Gallego, Mar,Izquierdo, Susana,Nicasio, Antonio I.,Onìate, Enrique,Sierra, Miguel A.
-
-
Read Online
- Selective oxidation of alcohols in the presence of an Os/O2-system
-
The osmium-catalyzed oxidation of alcohols with molecular oxygen to give aldehydes in good to excellent yields has been developed. Best results are obtained by using a buffered two-phase system with a constant pH of 10.4. Under optimized reaction conditions a remarkable catalyst productivity (TON up to 16600) is observed.
- D?bler, Christian,Mehltretter, Gerald M,Sundermeier, Uta,Eckert, Markus,Militzer, Hans-Christian,Beller, Matthias
-
-
Read Online
- Comparison of 2-acetylfuran formation between ribose and glucose in the Maillard reaction
-
Sugar type is a major factor regulating the reaction rates and pathways in Maillard reaction. Ribose and glucose were used to compare their reactivities and pathways of 2-acetylfuran formation. A stable isotope labeling method was used to study their reactivity. A 1:1 mixture of [13C 6]glucose and unlabeled ribose (or other unlabeled sugar) was reacted with proline at 145 °C for 40 min. The reactivity of each sugar was revealed by the ratio of isotopomers. The reactivity of sugars in 2-acetylfuran formation decreased in the order ribose, fructose, glucose, rhamnose, and sucrose. This method simplified the reaction system and the calculation process and gave a direct comparison of reactivity as seen via mass spectrum. The difference between glucose and ribose in 2-acetylfuran formation was that glucose could form 2-acetylfuran directly from cyclization of its intact carbon skeleton, whereas ribose first underwent degradation into fragments before forming a six-carbon unit leading to 2-acetylfuran. In the presence of cysteine, ribose could not generate 2-acetylfuran at a detectable level. When ribose was reacted with glycine, formaldehyde generated from glycine combined with ribose to form 2-acetylfuran. In other amino acids, a symmetric structure of the ribose intermediate was formed, making fragmentation more complicated.
- Wang, Yu,Ho, Chi-Tang
-
-
Read Online
- Copper-Catalyzed Stille Cross-Coupling Reaction and Application in the Synthesis of the Spliceostatin Core Structure
-
An efficient palladium-free Stille cross-coupling reaction of allylic bromides and functionalized organostannylfuran using catalytic copper halide has been developed. The coupling reaction was optimized using CuI and low catalyst loading (down to 5 mol %). The reaction was conveniently carried out at ambient temperature in the presence of inorganic base to afford the coupling product in good-to-excellent yields. The utility of this reaction was demonstrated in the synthesis of a furan with sensitive functionalities. A sulfolene moiety was utilized as a masking group for the sensitive diene. Noyori asymmetric reduction, Achmatowicz reaction, and Kishi reduction steps converted sulfolene to a highly substituted tetrahydropyran intermediate used in the synthesis of the highly potent antitumor agents, spliceostatins, and their derivatives.
- Ghosh, Arun K.,Born, Joshua R.,Veitschegger, Anne M.,Jurica, Melissa S.
-
-
Read Online
- Oxidation of alcohols by transfer hydrogenation: driving the equilibrium with an intramolecular trap
-
Levulinic acid and its esters participate in transfer hydrogenation with a range of secondary alcohols. Reduction of the levulinate leads to cyclisation into a γ-lactone, thereby acting as an oxidant for alcohols without the need for a large excess of reagents.
- Wise, Nicola J.,Williams, Jonathan M.J.
-
-
Read Online
- Enantioselective microbial oxidation of 1-arylethanol in an organic solvent
-
Reactivity in enantioselective oxidation of 1-arylethanol by Geotrichum candidum is improved when the microbe is entrapped with a water-adsorbent polymer and the reaction is conducted in hexane. Cyclohexanone as an additive improves the rate of oxidation as well as ee of the remained alcohol.
- Nakamura, Kaoru,Inoue, Yuko,Ohno, Atsuyoshi
-
-
Read Online
- Rearrangements of some furan and benzofuran 1,5,-dienols
-
Isomers of 1-(2-furyl)-methyl-3-buten-ols and their benzofuran analogs were studied for their oxy-Cope and anionic oxy-Cope reactivity.
- Martin,Wurster,Boylan,Borzilleri,Engel,Walsh
-
-
Read Online
- Potassium ferrate on wet alumina: Preparation and reactivity
-
The use of a wet alumina/potassium ferrate system for the oxidation of a range of activated alcohols is described. Studies are presented which delineate the scope and limitation of the procedure and include a new carbon-carbon bond cleavage reaction. (C) 2000 Elsevier Science Ltd.
- Caddick,Murtagh,Weaving
-
-
Read Online
- Examining of athermal effects in microwave-induced glucose/glycine reaction and degradation of polysaccharide from Porphyra yezoensis
-
Many reports claim the existence of athermal effects in microwave-induced reactions, and this challenge the assumption that the thermal effect (heating) is the sole factor in microwave heating. Therefore, microwave-induced Maillard reaction of d-glucose/g
- Zhou, Cunshan,Yu, Xiaojie,Ma, Haile,Liu, Shulan,Qin, Xiaopei,Yagoub, Abu El-Gasim A.,Owusu, John
-
-
Read Online
- Iron–PNP-Pincer-Catalyzed Transfer Dehydrogenation of Secondary Alcohols
-
The well-defined iron PNP pincer complex catalyst [Fe(H)(BH4)(CO)(HN{CH2CH2P(iPr)2}2] was used for the catalytic dehydrogenation of secondary alcohols to give the corresponding ketones. Using acetone as inexpensive hydrogen acceptor enables the oxidation with good to excellent yields. DFT computations indicate an outer-sphere mechanism and support the importance of an acceptor to achieve this transformation under milder conditions.
- Budweg, Svenja,Wei, Zhihong,Jiao, Haijun,Junge, Kathrin,Beller, Matthias
-
-
Read Online
- Characteristic flavor formation of thermally processed N-(1-deoxy-α-D-ribulos-1-yl)-glycine: Decisive role of additional amino acids and promotional effect of glyoxal
-
The role of amino acids and α-dicarbonyls in the flavor formation of Amadori rearrangement product (ARP) during thermal processing was investigated. Comparisons of the volatile compounds and their concentrations when N-(1-deoxy-α-D-ribulos-1-yl)-glycine r
- Zhan, Huan,Cui, Heping,Yu, Junhe,Hayat, Khizar,Wu, Xian,Zhang, Xiaoming,Ho, Chi-Tang
-
-
- The dehydrogenative oxidation of aryl methanols using an oxygen bridged [Cu-O-Se] bimetallic catalyst
-
Herein, we report a new protocol for the dehydrogenative oxidation of aryl methanols using the cheap and commercially available catalyst CuSeO3·2H2O. Oxygen-bridged [Cu-O-Se] bimetallic catalysts are not only less expensive than other catalysts used for the dehydrogenative oxidation of aryl alcohols, but they are also effective under mild conditions and at low concentrations. The title reaction proceeds with a variety of aromatic and heteroaromatic methanol examples, obtaining the corresponding carbonyls in high yields. This is the first example using an oxygen-bridged copper-based bimetallic catalyst [Cu-O-Se] for dehydrogenative benzylic oxidation. Computational DFT studies reveal simultaneous H-transfer and Cu-O bond breaking, with a transition-state barrier height of 29.3 kcal mol?1
- Choudhury, Prabhupada,Behera, Pradyota Kumar,Bisoyi, Tanmayee,Sahu, Santosh Kumar,Sahu, Rashmi Ranjan,Prusty, Smruti Ranjita,Stitgen, Abigail,Scanlon, Joseph,Kar, Manoranjan,Rout, Laxmidhar
-
supporting information
p. 5775 - 5779
(2021/04/12)
-
- Visible light mediated selective oxidation of alcohols and oxidative dehydrogenation of N-heterocycles using scalable and reusable La-doped NiWO4nanoparticles
-
Visible light-mediated selective and efficient oxidation of various primary/secondary benzyl alcohols to aldehydes/ketones and oxidative dehydrogenation (ODH) of partially saturated heterocycles using a scalable and reusable heterogeneous photoredox catalyst in aqueous medium are described. A systematic study led to a selective synthesis of aldehydes under an argon atmosphere while the ODH of partially saturated heterocycles under an oxygen atmosphere resulted in very good to excellent yields. The methodology is atom economical and exhibits excellent tolerance towards various functional groups, and broad substrate scope. Furthermore, a one-pot procedure was developed for the sequential oxidation of benzyl alcohols and heteroaryl carbinols followed by the Pictet-Spengler cyclization and then aromatization to obtain the β-carbolines in high isolated yields. This methodology was found to be suitable for scale up and reusability. To the best of our knowledge, this is the first report on the oxidation of structurally diverse aryl carbinols and ODH of partially saturated N-heterocycles using a recyclable and heterogeneous photoredox catalyst under environmentally friendly conditions.
- Abinaya, R.,Balasubramaniam, K. K.,Baskar, B.,Divya, P.,Mani Rahulan, K.,Rahman, Abdul,Sridhar, R.,Srinath, S.
-
p. 5990 - 6007
(2021/08/24)
-
- Preparation method of 2-acetylfuran
-
The invention discloses a preparation method of 2-acetylfuran, which comprises the following steps: taking furfural as a raw material, carrying out Grignard reaction to obtain furfuryl alcohol, and carrying out oxidation reaction on furfuryl alcohol in the presence of a catalyst in an oxygen-containing atmosphere to obtain 2-acetylfuran, wherein the catalyst is a 4-hydroxy-2, 2, 6, 6-tetramethylpyridine oxide (Temp) and potassium bromide. The method is simple in process, simple in catalyst and suitable for large-scale industrial production, the stability meets the market requirements of products, the product cost is lower than that of existing industrial production, and the product quality is better.
- -
-
Paragraph 0034; 0037-0039; 0040-0043
(2021/06/23)
-
- CtD strategy to construct stereochemically complex and structurally diverse compounds from griseofulvin
-
The Complexity to Diversity (CtD) strategy, a strategy for the synthesis of stereochemically complex and structurally diverse small molecules from natural products using ring-distortion reactions, was applied in the synthesis of a 47-member compound collection from the natural product griseofulvin. A Tsuji-Trost allylation and oxa-Michael cyclization tandem reaction was used for the first time in the CtD strategy to generate complex ring fused compounds.
- Li, Yu,Liu, Gong-Qing,Zhao, Rui-Han,Zhao, Yu,Zhu, Li
-
supporting information
p. 10755 - 10758
(2021/10/20)
-
- PhSe(O)OH/NHPI-catalyzed oxidative deoximation reaction using air as oxidant
-
A novel oxidative deoximation method was developed in this article. Compared with the reported organoselenium-catalyzed oxidative deoximation reaction, this reaction employed N-hydroxyphthalimide (NHPI) as the co-catalyst, so that the oxidative deoximation reaction could utilize air as oxidant in the green DMC solvent under mild reaction conditions. Control experiments and X-ray photoelectron spectroscopy (XPS) analysis results indicated that NHPI was essential for activating the catalytic organoselenium species. It could accelerate the activation of molecular oxygen in air to promote the reaction process. The reaction can avoid metal residues in product and is of potential application values in pharmaceutical industry due to the transition metal-free process.
- Shi, Yaocheng,Wang, Feng,Yang, Chenggen,Yu, Lei
-
-
- Selective oxidation of alkenes to carbonyls under mild conditions
-
Herein, a practical and sustainable method for the synthesis of aldehydes, ketones, and carboxylic acids from an inexpensive olefinic feedstock is described. This transformation features very sustainable and mild conditions and utilizes commercially available and inexpensive tetrahydrofuran as the additive, molecular oxygen as the sole oxidant and water as the solvent. A wide range of substituted alkenes were found to be compatible, providing the corresponding carbonyl compounds in moderate-to-good yields. The control experiments demonstrated that a radical mechanism is responsible for the oxidation reaction.
- Huo, Jie,Xiong, Daokai,Xu, Jun,Yue, Xiaoguang,Zhang, Pengfei,Zhang, Yilan
-
supporting information
p. 5549 - 5555
(2021/08/16)
-
- Aryl aldiketone and synthesis method thereof
-
The invention discloses an aryl aldehyde ketone and a synthesis method thereof, wherein an aryl aldehyde is synthesized from cheap olefin as a raw material. A commercially available inexpensive olefin is used as a raw material, ether is used as an additive, molecular oxygen serves as a sole oxidizing agent, water is used as a solvent, and the aldehyde and ketone are synthesized by column chromatography under a photocatalytic condition. The invention has the advantages of mild reaction conditions, green and environmental protection, simple experimental operation, good reaction selectivity, high product yield and the like.
- -
-
Paragraph 0026
(2021/09/26)
-
- Iron-catalyzed domino decarboxylation-oxidation of α,β-unsaturated carboxylic acids enabled aldehyde C-H methylation
-
A practical and general iron-catalyzed domino decarboxylation-oxidation of α,β-unsaturated carboxylic acids enabling aldehyde C-H methylation for the synthesis of methyl ketones has been developed. This mild, operationally simple method uses ambient air as the sole oxidant and tolerates sensitive functional groups for the late-stage functionalization of complex natural-product-derived and polyfunctionalized molecules.
- Gong, Pei-Xue,Xu, Fangning,Cheng, Lu,Gong, Xu,Zhang, Jie,Gu, Wei-Jin,Han, Wei
-
supporting information
p. 5905 - 5908
(2021/06/18)
-
- Visible-light photocatalytic selective oxidation of C(sp3)-H bonds by anion-cation dual-metal-site nanoscale localized carbon nitride
-
Selective oxidation of C(sp3)-H bonds to carbonyl groups by abstracting H with a photoinduced highly active oxygen radical is an effective method used to give high value products. Here, we report a heterogeneous photocatalytic alkanes C-H bonds oxidation method under the irradiation of visible light (λ= 425 nm) at ambient temperature using an anion-cation dual-metal-site modulated carbon nitride. The optimized cation (C) of Fe3+or Ni2+, with an anion (A) of phosphotungstate (PW123?) constitutes the nanoscale dual-metal-site (DMS). With a Fe-PW12dual-metal-site as a model (FePW), we demonstrate a A-C DMS nanoscale localized carbon nitride (A-C/g-C3N4) exhibiting a highly enhanced photocatalytic activity with a high product yield (86% conversion), selectivity (up to 99%), and a wide functional group tolerance (52 examples). The carbon nitride performs the roles of both the visible light response, and improves the selectivity for the oxidation of C(sp3)-H bonds to carbonyl groups, along with the function of A-C DMS in promoting product yield. Mechanistic studies indicate that this reaction follows a radical pathway catalyzed by a photogenerated electron and hole on A-C/g-C3N4that is mediated by thetBuO˙ andtBuOO˙ radicals. Notably, a 10 g scale reaction was successfully achieved for alkane photocatalytic oxidation to the corresponding product with a good yield (80% conversion), and high selectivity (95%) under natural sunlight at ambient temperature. In addition, this A-C/g-C3N4photocatalyst is highly robust and can be reused at least six times and the activity is maintained.
- Duan, Limei,Li, Peihe,Li, Wanfei,Liu, Jinghai,Liu, Ying,Liu, Zhifei,Lu, Ye,Sarina, Sarina,Wang, Jinghui,Wang, Yin,Wang, Yingying,Zhu, Huaiyong
-
p. 4429 - 4438
(2021/07/12)
-
- Hydration of Alkynes to Ketones with an Efficient and Practical Polyoxomolybdate-based Cobalt Catalyst
-
Hydration of alkynes to ketones is one of the most atom economical and universal methods for the synthesis of carbonyl compounds. However, the basic reaction usually requires organic ligand catalysts or harsh reaction conditions to insert oxygen into the C≡C bond. Here, we report an inorganic ligand supported cobalt (III) catalyst, (NH4)3[CoMo6O18(OH)6], which is supported by a central cobalt (III) mononucleus and a ring-shaped pure inorganic ligand composed of six MoVIO6 octahedrons to avoid the disadvantages of expensive and unrecyclable organic ligand catalysts or noble metal catalysts. Under mild conditions, the cobalt (III) catalyst can be used for the hydration of alkynes to ketones. The catalyst is non-toxic, green, and environment friendly. The catalyst can be recycled at least six times with high activity. According to control experiments, a reasonable mechanism is provided.
- Xie, Ya,Wang, Jingjing,Wang, Yunyun,Han, Sheng,Yu, Han
-
p. 4985 - 4989
(2021/10/12)
-
- Base-free oxidation of alcohols enabled by nickel(ii)-catalyzed transfer dehydrogenation
-
An efficient nickel(ii)-catalyzed transfer dehydrogenation oxidation of alcohols is reported that relies on cyclohexanone as the formal oxidant and does not require the use of an external base. The synthetic utility of this protocol is demonstratedviathe facile oxidation of structurally complicated natural products.
- Ye, Danfeng,Liu, Zhiyuan,Sessler, Jonathan L.,Lei, Chuanhu
-
supporting information
p. 11811 - 11814
(2020/10/13)
-
- Rapid access to 3-acyl indoles using ethyl acetate/triflic acid couple as the acylium donor and Cu(OAc)2catalysed aerial oxidation of indole benzoins
-
Esters are potential acyl donors but are relatively unexplored for that purpose. A facile installation of acyl groups at the C-3 position of indoles under triflic acid catalysed conditions with easily available and cheap esters as new acylating agents is described herein. Furthermore, heterocycles like N-protected pyrrole, furan and thiophene were also suitable substrates for similar C-2 acylation. Analogous C-3 benzoylated products of indole were obtained, albeit in lower yields, by using methyl benzoate as a benzoyl donor. The benzoylated products were synthesised in much better yields via a copper(ii) catalysed aerial oxidation of indole containing benzoins. This journal is
- Talukdar, Ranadeep
-
supporting information
p. 8876 - 8880
(2020/11/23)
-
- Synthesis, structures and catalytic activity of Pd(II) saccharinate complexes with monophosphines in direct arylation of five-membered heteroarenes with aryl bromides
-
A number of new Pd(II) saccharinate (sac) complexes bearing a range of phenyl (Ph), cyclohexyl (Cy) and alkyl (Me and Et) substituted tertiary phosphine ligands with systematically changing electronic and steric properties, namely trans-[PdCl(sac)(L)2] (L = PPh3 (1); PPh2Cy (3)), trans-[Pd(sac)2(H2O)(L)] (L = PPh3 (2); PPh2Cy (5)), trans-[Pd(sac)2(L)2] (L = PPh2Cy (4); PPhCy2 (6); PCy3 (8)), [PdCl(sac)(PCy3)(DMSO)] (7), trans-[Pd(sac)2(PPh2Me)(DMSO)] (9) and cis-[M(sac)2(L)2] (L = PPhMe2 (10); PPh2Et (11); PPhEt2 (12)), were synthesized and structurally characterized. The Pd(II) complexes were applied for direct C2/C5 arylation of five-membered heteroarenes such as furan, thiophene and thiazole derivatives with aryl bromides. Notably, arylation products up to 99% yields were obtained in the presence of the Pd(II) complexes. The catalytic mechanism of the direct arylation was proposed to proceed via a Pd(0)/Pd(II) pathway, due to elimination of the sac ligand in the Pd(II) complexes during catalysis.
- Yilmaz, Veysel T.,Icsel, Ceyda,Turgut, Omer R.,Aygun, Muhittin,Evren, Enes,Ozdemir, Ismail
-
-
- Selective Oxidation of Benzylic C-H Bonds Catalyzed by Cu(II)/{PMo12}
-
Precise catalytic regulation of carbon radical generation by a highly active oxygen radical to abstract the H atom in a C-H bond is an effective method for the selective activation of C-H synthetic chemistry. Herein, we report a facile catalyst system with commercially available copper(II)/{PMo12} to form a tert-butanol radical intermediate for the selective oxidation of benzylic C-H bonds. The reaction shows a broad range of substrates (benzyl methylene, benzyl alcohols) with good functional group tolerance and chemical selectivity. The corresponding carbonyl compounds were synthesized with good yields under mild conditions. DFT calculations and experimental analysis further demonstrated a reasonable carbon radical mechanism for this type of organic transformation reaction.
- Li, Peihe,Wang, Yingying,Wang, Xia,Wang, Yin,Liu, Ying,Huang, Keke,Hu, Jing,Duan, Limei,Hu, Changwen,Liu, Jinghai
-
p. 3101 - 3109
(2020/03/23)
-
- Preparation method of carbonyl compound
-
The invention provides a preparation method of a carbonyl compound, and relates to the technical field of organic synthesis. The preparation method of the carbonyl compound provided by the invention comprises the following steps of: mixing a compound A, an oxidizing agent, a catalyst and a polar solvent, and carrying out a photocatalytic oxidation reaction to obtain a carbonyl compound, wherein the catalyst is iron-phosphorus-tungsten loaded carbon nitride; wherein the compound A has a structure shown as a formula I, and in the formula I, R1 comprises hydrogen, a halogen group, a linear alkylgroup, an aryl group, an acyl group or an alkoxy group; R2 comprises hydrogen, a cycloalkenyl group, a cycloalkyl group, an aryl group or a heterocyclic group; R3 comprises hydrogen or hydroxyl; whenR1 is hydrogen or a halogen group, R2 and R3 are not hydrogen at the same time; and when R1 is hydrogen or a halogen group and R2 is hydrogen, R3 is not a hydroxyl group. The iron-phosphorus-tungstenloaded carbon nitride adopted by the invention belongs to a heterogeneous catalyst, the catalytic activity is high, the cyclic utilization rate is high, additives such as a ligand, acid or alkali arenot required to be added during use, the product yield is high, and the process is simple.
- -
-
Paragraph 0093-0094
(2020/11/12)
-
- Light and oxygen-enabled sodium trifluoromethanesulfinate-mediated selective oxidation of C-H bonds
-
Visible light-induced organic reactions are important chemical transformations in organic chemistry, and their efficiency highly depends on suitable photocatalysts. However, the commonly used photocatalysts are precious transition-metal complexes and elaborate organic dyes, which hamper large-scale production due to high cost. Here, for the first time, we report a novel strategy: light and oxygen-enabled sodium trifluoromethanesulfinate-mediated selective oxidation of C-H bonds, allowing high-value-added aromatic ketones and carboxylic acids to be easily prepared in high-to-excellent yields using readily available alkyl arenes, methyl arenes and aldehydes as materials. The mechanistic investigations showed that the treatment of inexpensive and readily available sodium trifluoromethanesulfinate with oxygen under irradiation of light could in situ form a pentacoordinate sulfide intermediate as an efficient photosensitizer. The method represents a highly efficient, economical and environmentally friendly strategy, and the light and oxygen-enabled sodium trifluoromethanesulfinate photocatalytic system represents a breakthrough in photochemistry. This journal is
- Fu, Hua,Liu, Can,Liu, Yong,Yang, Haijun,Zhu, Xianjin
-
supporting information
p. 4357 - 4363
(2020/07/14)
-
- Synthesis method of 2-acetylfuran
-
The invention discloses a synthesis method of 2-acetyl furan, which is characterized in that palladium salt and heteropolyacid are used as catalysts, 2-vinyl furan is used as a raw material, and oxygen-containing gas is used as an oxidizing agent to carry out an oxidation reaction to obtain the 2-acetyl furan. In the synthesis reaction process, use of organic solvents with strong irritation such as acetic anhydride and acetyl chloride is avoided, the reaction is carried out in a water phase system, and no pungent smell of the organic solvents exists in a production field. The product conversion rate is high, and a high-purity 2-acetyl furan product can be obtained.
- -
-
Paragraph 0025-0037
(2020/12/15)
-
- Electronic Asymmetry of an Annelated Pyridyl-Mesoionic Carbene Scaffold: Application in Pd(II)-Catalyzed Wacker-Type Oxidation of Olefins
-
The two donor modules of an annelated pyridyl-mesoionic carbene ligand (aPmic) have different σ- and π-bonding characteristics leading to its electronic asymmetry. A Pd(II) complex 1 featuring aPmic catalyzes the oxidation of a wide range of terminal olefins to the corresponding methyl ketones in good to excellent yields in acetonitrile. The catalytic reaction is proposed to proceed via syn-peroxypalladation and a subsequent rate-limiting 1,2-hydride shift, which is supported by kinetic studies. The electronic asymmetry of aPmic renders a well-defined coordination sphere at Pd. The favored arrangement of reactants on the metal center features an olefin trans to the pyridyl module and a tbutylperoxide trans to the carbene. This arrangement gains added stability by the π-delocalization paved by the compatible orbitals on Pd, the pyridyl module, and the olefin that is perpendicular to the Pd(aPmic) plane. The π-interactions are absent in an alternate arrangement wherein the olefin is trans to the carbene. Density functional theory studies reveal the matching orbital overlaps responsible for the preferred arrangement over the other. This work provides an orbital description for the electronic asymmetry of aPmic.
- Bera, Jitendra K.,Dutta, Indranil,Kunnikuruvan, Sooraj,Reshi, Noor U Din,Saha, Sayantani,Yadav, Suman
-
p. 11385 - 11393
(2020/11/23)
-
- Method for preparing 2-acyl furan
-
The invention relates to a method for preparing 2-acyl furan. The method is characterized by comprising the following steps: (1) controlling the temperature to -10-40 DEG C, and adding 70-98% of a water phase or 10-90% of a mixed liquid of the water phase and an organic phase, 0.0001-2.0% of an osmium compound and 0.001-5.0% of an amine compound into a reaction container so as to obtain a reactionliquid; (2) feeding the reaction liquid into a sealed reactor, and performing gas exchange to provide an aerobic environment for reactions; (3) adding 1-(2-furyl)-1-alkyl methanol into the sealed reactor, and controlling the pressure to 0-20MPa and the temperature to 0-200 DEG C for 1-74 hours; and (4) after the reaction is stopped, performing cooling to the room temperature, performing pressurerelease to the barometric pressure, adding sodium hydrogen sulfate and acetic acid, performing extraction, and performing organic phase vacuum distillation refining, so as to obtain a 2-acyl furan product. The method has the advantages that technical and economical defects of a conventional synthesis route can be avoided, process procedures can be reduced, consumption and emission can be reduced,the energy consumption and the cost can be lowered, and the method is applicable to capacity increase industrial production.
- -
-
Paragraph 0022-0023; 0025-0026; 0028
(2019/12/25)
-
- Highly efficient and practical aerobic oxidation of alcohols by inorganic-ligand supported copper catalysis
-
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
-
supporting information
p. 4069 - 4075
(2019/08/07)
-
- Compartmentalized Nanoreactors for One-Pot Redox-Driven Transformations
-
This contribution introduces poly(2-oxazoline)-based shell cross-linked micelles (SCMs) as nanoreactors to realize one-pot redox-driven deracemizations of secondary alcohols in aqueous media. TEMPO and Rh-TsDPEN moieties are spatially positioned into the hydrophilic corona and the hydrophobic micelle core, respectively. TEMPO catalyzes the oxidation of racemic secondary alcohols into ketones, while Rh-TsDPEN catalyzes the asymmetric transfer hydrogenation (ATH) of these ketones to afford enantioenriched secondary alcohols. Both catalysts, the Rh-TsDPEN complex and TEMPO, are incompatible with each other and the SCMs are designed to provide indispensable catalyst site isolation. Kinetic studies show that the SCMs enhance the reactivity of the immobilized catalysts, in comparison to those for the unsupported analogues under the same reaction conditions. Our nanoreactors can perform deracemizations on a broad range of secondary alcohol substrates and are reusable in a continuous manner while maintaining high activity.
- Qu, Peiyuan,Kuepfert, Michael,Jockusch, Steffen,Weck, Marcus
-
p. 2701 - 2706
(2019/03/08)
-
- Preparation method of 2-acetylfuran
-
The invention relates to a preparation method of 2-acetylfuran. The method is characterized by including the steps of: (1) adding acetic acid, acetic anhydride and a catalyst zinc salt into a reactioncontainer under stirring at a temperature ranging from -10DEG C to 30DEG C, after dissolution of the catalyst, adding furan and acetic anhydride dropwise, with the acetic anhydride, acetic acid, furan and the catalyst zinc salt being in a mass ratio of 1:0.01-5.0:0.1-2.0:0.01-0.2; (2) sealing the reactor, controlling the pressure at 0-1.0MPa, and carrying out reaction at 30-120DEG C for 0.1-12h;(3) then performing cooling to room temperature, conducting reduced pressure distillation, controlling the vacuum degree ranging from -0.10MPa to -0.05MPa and the temperature at 20-80DEG C, and recovering acetic acid; and (4) further conducting reduced pressure distillation, controlling the vacuum degree ranging from -0.10MPa to -0.05MPa and the temperature at 40-90DEG C, and conducting refining to obtain 2-acetylfuran. The method provided by the invention improves the furan utilization and reduces the material loss, directly distills recovered acetic acid to obtain a finished product, lowersthe difficulty of later recovery of the finished product, greatly reduces the process flow, lowers the energy consumption, and eliminates environmental pollution, thus being suitable for industrial production of expanding production capacity.
- -
-
Paragraph 0012-0017
(2019/11/28)
-
- Iron-catalyzed oxidative functionalization of C(sp3)-H bonds under bromide-synergized mild conditions
-
An efficient oxidation and functionalization of C-H bonds with an inorganic-ligand supported iron catalyst and hydrogen peroxide to prepare the corresponding ketones was achieved using the bromide ion as a promoter. Preliminary mechanistic investigations indicated that the bromide ion can bind to FeMo6 to form a supramolecular species (FeMo6·2Br), which can effectively catalyze the reaction.
- Yu, Han,Zhao, Qixin,Wei, Zheyu,Wu, Zhikang,Li, Qi,Han, Sheng,Wei, Yongge
-
supporting information
p. 7840 - 7843
(2019/07/12)
-
- Method for preparing ketone compound through ethylbenzene compound
-
The invention provides a method for preparing a ketone compound through an ethylbenzene compound, and belongs to the field of catalytic chemistry. According to the method, the ethylbenzene compound isadded into a mixed solvent of water and acetonitrile, and then mixed with an oxidizing agent, and then a catalytic oxidation reaction is conducted after copper acetate and phosphomolybdic acid are added to obtain the ketone compound. According to the method, in the preparing process, a Cu/POM green catalytic system is formed to serve as a catalyst, the preparing method is simplified, preparationof polyoxometallate catalysts is not needed, polyoxometalates and metal copper salt are used together to serve as a green catalytic system, the catalytic effect is excellent, the POMs can overcome thecatalysis bottleneck of the metal copper salt, and effective catalysis of a model reaction is achieved.
- -
-
Paragraph 0070-0072
(2019/10/22)
-
- Efficient Palladium(0) supported on reduced graphene oxide for selective oxidation of olefins using graphene oxide as a ‘solid weak acid’
-
Selective oxidation of olefin derivatives to ketones has made innovative development over palladium(0) supported on reduced graphene oxide. Compared to traditional Wacker oxidation, the novel method offers an economical and environment-friendly option by using graphene oxide (GO) as a ‘solid weak acid’ instead of classical homogeneous catalysts like H2SO4 and CF3COOH. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscopy images of Pd0/RGO showed that the nanoscaled Pd particles generated at the flake structure of reduced graphene oxide. Under optimized condition, up to 44 kinds of ketones with different structures can be prepared with excellent yields.
- Gao, Xi,Zhou, Jianhao,Peng, Xinhua
-
-
- Base-Free and Acceptorless Dehydrogenation of Alcohols Catalyzed by an Iridium Complex Stabilized by a N, N, N-Osmaligand
-
The preparation of a N,N,N-osmaligand, its coordination to iridium to afford an efficient catalyst precursor, and the catalytic activity of the latter in dehydrogenation reactions of hydrogen carriers based on alcohols are reported. Complex OsH2Cl2(PiPr3)2 (1) reacts with 3-(2-pyridyl)pyrazol to give the osmium(II) complex 2H, which contains an acidic hydrogen atom. Deprotonation of the latter by the bridging methoxy groups of the dimer [Ir(μ-OMe)(n4-COD)]2 (COD = 1,5-cyclooctadiene) leads to Ir(2)( n 4-COD) (3), where osmaligand 2 has a free-nitrogen atom. Iridium complex 3 catalyzes the dehydrogenation of secondary and primary alcohols to ketones and aldehydes or esters, respectively, and the dehydrogenation of diols to lactones. Cyclooctatriene is detected during the catalysis by GC-MS, suggesting that the true catalyst of the reactions is a dihydride IrH2(2)-species with osmaligand 2 acting as N,N,N-pincer. The presence of a phenyl group in the substrates favors the catalytic processes. The dehydrogenative homocoupling of primary alcohols to esters appears to take place via the transitory formation of hemiacetals.
- Alabau, Roberto G.,Esteruelas, Miguel A.,Martínez, Antonio,Oliván, Montserrat,O?ate, Enrique
-
p. 2732 - 2740
(2018/09/10)
-
- Visible-Light-Driven Photocatalytic Oxidation of Organic Chlorides Using Air and an Inorganic-Ligand Supported Nickel-Catalyst Without Photosensitizers
-
Engineering photoredox-triggered chemical transformation via visible light has been an emerging area in organic synthesis. However, most of the well-established photocatalysts are based upon either transition metal complexes involved with noble metals and organic ligands or photosensitive organic dyes, the development of pure inorganic molecular photocatalysts that could provide better stability and durability is greatly retarded. Herein we discover that the Anderson polyoxometalate (POM) Na4[NiMo6O18(OH)6] (1), which consists of pure inorganic framework built from a central NiII core supported by six MoVIO6 inorganic scaffold/ligands, can be used as a powerful photocatalyst. Upon irradiation with visible light (>400 nm), the compound can catalyze, in high efficiency, a wide range of reactions, including the oxidative cross-coupling reaction of chlorides with amines, as well as oxidation of chlorides using molecular oxygen, affording various imines, aldehydes, and ketones, respectively in high selectivity and good yields. Owing to the robust inorganic framework, this catalyst exhibits excellent stability during the catalysis and reusability with little loss of the catalytic activity, thus providing an alternative without use of complicated organic ligands and expensive noble metal-based photosensitizers.
- Yu, Han,Wang, Jingjing,Zhai, Yongyan,Zhang, Mengqi,Ru, Shi,Han, Sheng,Wei, Yongge
-
p. 4274 - 4279
(2018/09/10)
-
- Selective aerobic oxidation of halides and amines with an inorganic-ligand supported zinc catalyst
-
A practical, efficient and environmentally benign catalytic protocol for the oxidative cross-coupling reaction of halides with amines, oxidative self-coupling of amines and oxidation of halides was developed with inorganic-ligand supported ZnPOM (NH4)4[ZnMo6O18(OH)6] using molecular oxygen. This method mainly utilizes an inorganic polymolybdate ligand to support the Zn2+ ion, avoiding the use of complicated organic ligands.
- Wang, Jingjing,Zhai, Yongyan,Wang, Ying,Yu, Han,Zhao, Wenshu,Wei, Yongge
-
supporting information
p. 13323 - 13327
(2018/10/15)
-
- Formation of Reactive Intermediates, Color, and Antioxidant Activity in the Maillard Reaction of Maltose in Comparison to d -Glucose
-
In this study, the Maillard reaction of maltose and d-glucose in the presence of l-alanine was investigated in aqueous solution at 130 °C and pH 5. The reactivity of both carbohydrates was compared in regards of their degradation, browning, and antioxidant activity. In order to identify relevant differences in the reaction pathways, the concentrations of selected intermediates such as 1,2-dicarbonyl compounds, furans, furanones, and pyranones were determined. It was found, that the degradation of maltose predominantly yields 1,2-dicarbonyls that still carry a glucosyl moiety and thus subsequent reactions to HMF, furfural, and 2-acetylfuran are favored due to the elimination of d-glucose, which is an excellent leaving group in aqueous solution. Consequently, higher amounts of these heterocycles are formed from maltose. 3-deoxyglucosone and 3-deoxygalactosone represent the only relevant C6-1,2-dicarbonyls in maltose incubations and are produced in nearly equimolar amounts during the first 60 min of heating as byproducts of the HMF formation.
- Kanzler, Clemens,Schestkowa, Helena,Haase, Paul T.,Kroh, Lothar W.
-
p. 8957 - 8965
(2017/10/17)
-
- Alcohol Oxidations Using Reduced Polyoxovanadates
-
A full account of our recently communicated room temperature alcohol oxidation using reduced polyoxovanadates (r-POVs) is presented. Extensive optimizations revealed optimal conditions employing 0.02 equiv. of r-POV catalyst Cs5(V14As8O42Cl), 5 equiv. tert-butyl hydrogen peroxide (tBuOOH) as the terminal co-oxidant, in an acetone solvent for the quantitative oxidation of aryl-substituted secondary alcohols to their ketone products. The substrate scope tolerates most aryl substituted secondary alcohols in good to quantitative yields while alkyl secondary and primary activated alcohols were sluggish in comparison under similar conditions. Catalyst recyclability was successful on a 1.0?mmol scale of starting alcohol 1-phenylethanol. The oxidation was also successfully promoted by the VIV/VV mixed valent polyoxovanadate (POV) Cs11Na3Cl5(V15O36Cl). Finally, a third POV, Cs2.64(V5O9)(AsO4)2, was investigated for catalytic activity using our established reaction protocol, but proved ineffective as compared to the other two r-POV catalysts. This study expands the field of POM-mediated alcohol oxidations to include underexplored r-POV catalysts. While our catalysts do not supplant the best catalysts known for the transformation, their study may inform the development of other novel oxidative transformations mediated by r-POVs.
- Campbell, McKenzie L.,Sulejmanovic, Dino,Schiller, Jacqueline B.,Turner, Emily M.,Hwu, Shiou-Jyh,Whitehead, Daniel C.
-
-
- Production of p-Methylstyrene and p-Divinylbenzene from Furanic Compounds
-
A four-step catalytic process was developed to produce p-methylstyrene from methylfuran, a biomass-derived species. First, methylfuran was acylated over zeolite H-Beta with acetic anhydride. Second, the acetyl group was reduced to an ethyl group with hydrogen over copper chromite. Third, p-ethyltoluene was formed through Diels–Alder cycloaddition and dehydration of 2-ethyl-5-methyl-furan with ethylene over zeolite H-Beta. Dehydrogenation of p-ethyltoluene to yield p-methylstyrene completes the synthesis but was not investigated because it is a known process. The first two steps were accomplished in high yield (>88 %) and the Diels–Alder step resulted in a 67 % yield of p-ethyltoluene with a 99.5 % selectivity to the para isomer (final yield of 53.5 %). The methodology was also used for the preparation of p-divinylbenzene. It is shown that acylation of furans over H-Beta zeolites is a highly selective and high-yield reaction that could be used to produce other valuable molecules from biomass-derived furans.
- Koehle, Maura,Sara?i, Erisa,Dauenhauer, Paul,Lobo, Raul F.
-
-
- A Novel Consecutive Approach for the Preparation of Cu–MgO Catalysts with High Activity for Hydrogenation of Furfural to Furfuryl Alcohol
-
Abstract: A consecutive approach is introduced and tested for the first time to synthesize copper-magnesia catalysts with different (Cr, Ca, and Co) promoters for the catalytic hydrogenation of furfural. The comparison of the activity of these catalysts with that prepared via conventional co-precipitation indicated the superior activity of the former. A stable conversion of furfural (up to 91%) to furfuryl alcohol was achieved over the thus-prepared Cu–MgO and CaCu–MgO catalysts. However, both CoCu–MgO and CaCu–MgO demonstrated higher selectivities (about 99%) than the other two samples (Cu–MgO and CrCu–MgO). No direct interconnection was established between the catalytic activity and structural features of the catalysts, however. Graphical Abstract: [Figure not available: see fulltext.]
- Ghashghaee, Mohammad,Sadjadi, Samahe,Shirvani, Samira,Farzaneh, Vahid
-
p. 318 - 327
(2017/02/18)
-
- Acceptorless dehydrogenation and aerobic oxidation of alcohols with a reusable binuclear rhodium(II) catalyst in water
-
A water-soluble binuclear rhodium(ii) complex was found to be an efficient catalyst for both acceptorless dehydrogenation and aerobic oxidation of alcohols under air to produce carboxylic acids or ketones in water. The catalyst is highly efficient with substrate/catalyst ratios up to 5 × 103 being feasible, and could be recycled 19 times without significant loss of activity.
- Wang, Xuewei,Wang, Chao,Liu, Yuxuan,Xiao, Jianliang
-
supporting information
p. 4605 - 4610
(2016/09/04)
-
- Room-temperature catalytic oxidation of alcohols with the polyoxovanadate salt Cs5(V14As8O42Cl)
-
While many known methods for oxidation mediated by polyoxometalates (POMs) employ environmentally friendly co-oxidants, they tend to employ large catalyst loadings (e.g. 40 mol%) and costly high reaction temperatures (~90-135 °C) that potentially contribute to the degradation of the catalyst and reduce their effectiveness. Herein, we present some initial results demonstrating a room temperature catalytic oxidation using the reduced salt-inclusion polyoxometalate, Cs5(V14As8O42Cl), that contains polyoxovanadate (POV) clusters as an efficient catalyst (e.g., 2 mol%) in the transformation of secondary alcohols to their corresponding ketones in very good to quantitative yields. Further, the catalyst can be suspended on celite and recycled.
- Campbell, McKenzie L.,Sulejmanovic, Dino,Schiller, Jacqueline B.,Turner, Emily M.,Hwu, Shiou-Jyh,Whitehead, Daniel C.
-
p. 3208 - 3213
(2016/05/24)
-
- Methods to delay deactivation of zeolites on furan acylation: Continuous liquid-phase technology and solvent effects
-
The continuous liquid-phase Friedel-Crafts acylation of furan with acetic anhydride was first carried out in a fixed-bed reactor over an H-beta zeolite. A three-level, four-variable Box-Behnken design combined with response surface methodology was employed to determine the optimal acylation conditions, and the accuracy of the model was verified by validation experiments. In this study, it was found that lower liquid velocity and stronger polarity of the solvent were conducive to enhancing the catalytic activity and stability of the H-beta zeolite. The reaction was limited by the acid sites being poisoned due to the adsorption of the by-product and pore blockage. Moreover, the carbon deposit was proved to be the main reason for the deactivation of the H-beta zeolite by using GC-MS, 13C NMR MAS, 27Al NMR MAS, TG/DTG and NH3-TPD.
- Xiong, Yuannan,Chen, Wenqi,Ma, Jianjun,Chen, Zhihua,Zeng, Aiwu
-
p. 103695 - 103702
(2015/12/23)
-
- Synthesis of industrially important aromatic and heterocyclic ketones using hierarchical ZSM-5 and Beta zeolites
-
Hierarchical ZSM-5 and Beta zeolites were investigated in the synthesis of wide range of industrially important aromatic/heterocyclic ketones by Friedel-Crafts acylation and benzoylation reactions. For comparative study, conventional ZSM-5 and Beta, and amorphous mesoporous Al-MCM-41 were investigated. Hierarchical zeolites were prepared by multi-ammonium structure directing agents whereas conventional zeolites were prepared by mono-ammonium structure directing agents. Among the catalysts investigated in this study, hierarchical Beta exhibited the highest reactant conversion in the acylation and benzoylation reactions. In this study, the systematic assessment of the catalytic activity of acid catalysts for wide range of aromatic and heterocyclic compounds is shown under one umbrella. To the best of our knowledge, these reactions over hierarchical zeolites (ZSM-5 and Beta) are reported here for the first time. Structure activity relationship is explained based on the physico-chemical properties, molecular size, reactivity of reactants, and reaction mechanism. Catalysts can be easily recovered and reused with negligible loss in the catalytic activity.
- Kore, Rajkumar,Srivastava, Rajendra,Satpati, Biswarup
-
p. 129 - 141
(2015/09/28)
-
- Highly practical oxidation of benzylic alcohol in continuous-flow system with metal-free catalyst
-
Oxidation of benzylic alcohol to ketone or aldehyde is one of the most challenging reactions in terms of green chemistry. We report herein that employing H2O2, catalytic amount of Br- and acid in continuous-flow system to realize oxidation of benzylic alcohols with broad substrate scope and high selectivity. More importantly, no over oxidation to acid was obtained and it showed higher selectivity to 2° hydroxyl groups rather than 1°.
- Liu, Chengkou,Fang, Zheng,Yang, Zhao,Li, Qingwen,Guo, Shiyu,Zhang, Kai,Ouyang, Pingkai,Guo, Kai
-
p. 5973 - 5976
(2015/10/28)
-
- Highly practical sodium(i)/azobenzene catalyst system for aerobic oxidation of benzylic alcohols
-
An economic, environmental and practical aerobic oxidation of benzylic alcohols and hetero aryl alcohols to the corresponding carbonyl compounds with good substrate scope is disclosed for the first time. Good to excellent yields were obtained by employing economic and commercially available sodium bromide and a catalytic amount of azobenzene under metal-free and ligand-free conditions. Moreover, aldehydes and acids, the oxidation products of benzylic 1° alcohols, could be obtained using sodium bromide and sodium hydroxide as the co-catalyst respectively in high yields.
- Liu, Chengkou,Fang, Zheng,Yang, Zhao,Li, Qingwen,Guo, Shiyu,Guo, Kai
-
p. 79699 - 79702
(2015/10/06)
-
- N-Functionalized Amino Acids Promoted Aerobic Copper-Catalyzed Oxidation of Benzylic Alcohols in Water
-
Instead of traditional N,N-bidentate ligands, N-functionlized amino acids were used as powerful N,O-bidentate ligands in aerobic copper/TEMPO-catalyzed system for promoting oxidation of benzylic alcohols. Under the optimized reaction conditions, a wide range of primary and secondary benzylic alcohols have been efficiently converted into aldehydes and ketones with good to excellent yields in water.
- Zhang, Guofu,Lei, Jie,Han, Xingwang,Luan, Yuxin,Ding, Chengrong,Shan, Shang
-
p. 779 - 784
(2015/03/30)
-
- SYNTHESIS OF FUELS AND CHEMICALS FROM SUGARS
-
Methods to synthesize useful alcohol and aromatic hydrocarbon products from sorbitol derived from sugars are described. Sorbitol is dehydrated to form furans such as 2-acetylfuran which is hydrogenated to form hexanols, ethyl tetrahydrofuran, etc useful as fuels and chemicals for industry and commerce. Sorbitol may also be heated over a dehydrating catalyst to form aromatic hydrocarbons useful as fuels.
- -
-
-
- Silver-containing microemulsion as a high-efficient and recyclable catalytic system for hydration of alkynes
-
A silver-catalyzed highly efficient and regioselective synthesis of ketones from a wide range of alkynes is described. The reaction is dramatically accelerated by its performance in aqueous emulsion, which is self-assembled by the addition of silver perfluorooctanesulfonate (1) and perfluorooctanesulfonic acid (PFOS) to water. The reaction is conducted under convenient conditions with broad substrate scope, including a variety of aromatic and aliphatic terminal alkynes and internal alkynes. Furthermore, the air- and light-stable silver catalytic microemulsion can be reused for 4 times with minimal change in catalytic efficiency.
- Dong, Qizhi,Li, Ningbo,Qiu, Renhua,Wang, Jinying,Guo, Cancheng,Xu, Xinhua
-
p. 122 - 127
(2015/10/12)
-
- Heterocycle-substituted tetrazole ligands for copper-catalysed aerobic oxidation of alcohols
-
An efficient copper-catalysed aerobic oxidation of alcohols has been established, which employed heterocycle-substituted tetrazoles as ligands. The commercially available (S)-5-(pyrrolidin-2-yl)-1H-tetrazole proved as the best ligand for this oxidation. Under optimized conditions, the substrate scope was broadened. A plausible mechanism was also proposed.
- Liu, Yangyang,Xie, Aming,Li, Junjian,Xu, Xiao,Dong, Wei,Wang, Boliang
-
p. 9791 - 9796
(2015/01/09)
-
- Nanostructured RuO2 on MWCNTs: Efficient catalyst for transfer hydrogenation of carbonyl compounds and aerial oxidation of alcohols
-
Multiwall carbon nanotubes (MWCNTs)/ruthenium dioxide nanoparticles (RuO2NPs) composite was prepared by a straightforward 'dry synthesis' method. After being well characterized, the prepared composite was used as a nanocatalyst (RuO2/MWCNT) for the transfer hydrogenation of carbonyl compounds. The excellent adhesion of RuO2NPs on the anchoring sites of MWCNTs was confirmed by TEM and Raman analyses. The weight percentage (7.97 wt%) and the chemical state (+4) of Ru in RuO2/MWCNT was confirmed by EDS and XPS analyses, respectively. It was found that the RuO2/MWCNT has a higher specific surface area of 189.3 m2 g-1. Initially the reaction conditions were optimized and then the scope of the catalytic system was extended with a wide range of carbonyl compounds. The influence of the size of RuO2NPs on the transfer hydrogenation of carbonyl compounds was also studied. The RuO2/MWCNT is highly chemoselective, heterogeneous in nature, reusable and highly stable. Owing to the high stability of the used catalyst (u-RuO2/MWCNT), it was further calcinated at high temperature to obtain RuO2 nanorods (NRs) hybrid MWCNTs. Then the hybrid material was used as a catalyst (r-RuO 2/MWCNT) for the aerial oxidation of alcohols and the result was found to be good.
- Gopiraman,Babu, S. Ganesh,Karvembu,Kim
-
-
- Highly efficient dehydrogenation of secondary alcohols catalyzed by iridium-CNP complexes
-
A new highly practical method is presented for dehydrogenation of secondary alcohols to the corresponding ketones catalyzed by the iridium-CNP complexes. The reactions are compatible with substrates bearing diverse functional groups and proceed efficiently under mild conditions.
- Wang, Dawei,Zhao, Keyan,Yang, Shuyan,Ding, Yuqiang
-
p. 2016 - 2020
(2015/02/19)
-
- IMPROVED METHOD OF MAKING INTERNAL DEHYDRATION PRODUCTS OF SUGAR ALCOHOLS
-
A process is provided for making isohexides such as isosorbide with reduced color and/or improved color stability on storage, wherein ionic species in the crude dehydration product mixture are chromatographically substantially separated from the remainder of the crude product mixture, then the remainder is refined to yield a finished product for further use or sale.
- -
-
Paragraph 0086
(2014/05/24)
-
- L-Proline: An efficient N,O-bidentate ligand for copper-catalyzed aerobic oxidation of primary and secondary benzylic alcohols at room temperature
-
A novel and highly practical copper-catalyzed aerobic alcohol oxidation system with l-proline as the ligand at room temperature has been developed. A wide range of primary and secondary benzylic alcohols tested have been smoothly transformed into corresponding aldehydes and ketones with high yields and selectivities.
- Zhang, Guofu,Han, Xingwang,Luan, Yuxin,Wang, Yong,Wen, Xin,Ding, Chengrong
-
supporting information
p. 7908 - 7910
(2013/09/02)
-
