- Oxidative esterification of renewable furfural on cobalt dispersed on ordered porous nitrogen-doped carbon
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A series of highly dispersed cobalt-based catalysts on N-doped ordered porous carbon (Co-NOPC) were synthesized using the sacrificiallate method. MCM-41, ZSM-5 and SBA-15 were employed as hard templates with 2,2′-bipyridine as the ligand. The physical and
- Yin, Defeng,Zheng, Yanxia,Yang, Lixi,Li, Shuyue,Zhu, Daqing,Guo, Yafei,Zuo, Cuncun,Li, Yuchao,Huang, Haofei,Wang, Ming
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- High-efficiency oxidative esterification of furfural to methylfuroate with a non-precious metal Co-N-C/MgO catalyst
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From both fundamental and practical perspectives, the production of chemicals from biomass resources using high-efficiency non-precious metal catalysts is important. However, many processes require addition of stoichiometric or excess quantities of base,
- Huo, Na,Ma, Hong,Wang, Xinhong,Wang, Tianlong,Wang, Gang,Wang, Ting,Hou, Leilei,Gao, Jin,Xu, Jie
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- On the nature of the active sites in the selective oxidative esterification of furfural on Au/ZrO2 catalysts
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Two catalysts, based on gold on zirconia and prepared in the same way, except for the different thermal treatment in air after the addition of gold (0.4% wt), show a quite different behavior in furfural oxidative esterification, particularly in the select
- Ampelli,Barbera,Centi,Genovese,Papanikolaou,Perathoner,Schouten,van der Waal
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- Study of the oxidative esterification of furfural catalyzed by Au25(glutathione)18 nanocluster deposited on zirconia
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Au/ZrO2 catalyst prepared from Au25(SG)18 nanoclusters (SG stands for glutathione) deposited on ZrO2 has shown to be an efficient system for the oxidative esterification of furfural with methanol. The influence of the supported nanoclusters was studied and showed that partial calcination of the supported nanoclusters at 300 °C was sufficient for a quantitative formation of methyl-2-furoate even in the absence of a base. In the presence of 0.27 mol% of Au, initial activities up to 250 h?1 were obtained at 100 °C under 6 bar of O2. The reactivity was extended to the oxidative esterification of furfuryl alcohol and the formation of various products and intermediates was discussed.
- Shahin, Zahraa,Rataboul, Franck,Demessence, Aude
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- Ultrahigh-Content Nitrogen-doped Carbon Encapsulating Cobalt NPs as Catalyst for Oxidative Esterification of Furfural
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It is an attractive and challenging topic to endow non-noble metal catalysts with high efficiency via a nitrogen-doping approach. In this study, a nitrogen-doped carbon catalyst with high nitrogen content encapsulating cobalt NPs (CoOx@N-C(g))
- Wang, Ting,Ma, Hong,Liu, Xin,Luo, Yang,Zhang, Shujing,Sun, Yuxia,Wang, Xinhong,Gao, Jin,Xu, Jie
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- A tunable process: Catalytic transformation of renewable furfural with aliphatic alcohols in the presence of molecular oxygen
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The tunable transformation of renewable furfural with aliphatic alcohols in the presence of O2 is developed. Based on a nano Au catalyst and potassium carbonate, a 91.8% yield of methyl 2-furoate with 98.7% selectivity is obtained via the oxidative esterification in a furfural-methanol-O2 system; while a 91.4% yield of 3-(furan-2-yl-)-2-methylacrylaldehyde with 97.2% selectivity is attained via the oxidative condensation in a furfural-n-propanol-O2 system. This journal is
- Tong, Xinli,Liu, Zonghui,Yu, Linhao,Li, Yongdan
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- Metal silicotungstate salts as catalysts in furfural oxidation reactions with hydrogen peroxide
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In this work, metal cations exchanged silicotungstic acid salts were synthesized and evaluated as catalysts in furfural oxidative esterification reactions with hydrogen peroxide in alkyl alcohols solution. The protons of silicotungstic acid were totally e
- Rodrigues, Alana A.,da Silva, Márcio J.
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- Oxidation of furfural with H2O2 in the presence of a photogenerated iron catalyst
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Visible irradiation of a methanolic solution of furfural containing dilute aqueous H2O2 and PF6 (1: R=H, Cl or CH3) as catalyst yields methyl 2-furoate quantitatively.After photodecomplexation, the inorganic FeII,III catalyst can b
- Moulines, Francoise,Ruiz, Jaime,Astruc, Didier
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- Oxidative esterification of furfural over Au-Pd/HAP-T and Au-Ag/HAP-T bimetallic catalysts supported on mesoporous hydroxyapatite nanorods
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The conversion of furfural, a lignocellulose biomass, into fuels and value-added fine chemicals has attracted many researchers. In this study, structurally uniform and porous hydroxyapatite nanorods (HAP-T) with the gel composition 1Ca2+:0.66PO
- Radhakrishnan, Ramakrishnan,Kannan, Kathiravan,Kumaravel, Sakthivel,Thiripuranthagan, Sivakumar
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- GPR52 Antagonist Reduces Huntingtin Levels and Ameliorates Huntington's Disease-Related Phenotypes
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GPR52 is an orphan G protein-coupled receptor (GPCR) that has been recently implicated as a potential drug target of Huntington's disease (HD), an incurable monogenic neurodegenerative disorder. In this research, we found that striatal knockdown of GPR52 reduces mHTT levels in adult HdhQ140 mice, validating GPR52 as an HD target. In addition, we discovered a highly potent and specific GPR52 antagonist Comp-43 with an IC50 value of 0.63 μM by a structure-activity relationship (SAR) study. Further studies showed that Comp-43 reduces mHTT levels by targeting GPR52 and promotes survival of mouse primary striatal neurons. Moreover, in vivo study showed that Comp-43 not only reduces mHTT levels but also rescues HD-related phenotypes in HdhQ140 mice. Taken together, our study confirms that inhibition of GPR52 is a promising strategy for HD therapy, and the GPR52 antagonist Comp-43 might serve as a lead compound for further investigation.
- Wang, Congcong,Zhang, Yu-Fang,Guo, Shimeng,Zhao, Quan,Zeng, Yanping,Xie, Zhicheng,Xie, Xin,Lu, Boxun,Hu, Youhong
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p. 941 - 957
(2020/11/30)
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- N-acylhydrazones confer inhibitory efficacy against New Delhi metallo-β-lactamase-1
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The expression of β-lactamases, especially metallo-β-lactamases (MβLs) in bacteria is one of the main causes of drug resistance. In this work, an effective N-acylhydrazone scaffold as MβL inhibitor was constructed and characterized. The biological activity assays indicated that the synthesized N-acylhydrazones 1–11 preferentially inhibited MβL NDM-1, and 1 was found to be the most effective inhibitor with an IC50 of 1.2 μM. Analysis of IC50 data revealed a structure–activity relationship, which is that the pyridine and hydroxylbenzene substituents at 2-position improved inhibition of the compounds on NDM-1. ITC and enzyme kinetics assays suggested that it reversibly and competitively inhibited NDM-1 (Ki = 0.29 ± 0.05 μM). The synthesized N-acylhydrazones showed synergistic antibacterial activities with meropenem, reduced 4–16-fold MIC of meropenem on NDM-1- producing E. coli BL21 (DE3), while 1 restored 4-fold activity of meropenem on K. pneumonia expressing NDM-1 (NDM-K. pneumoniae). The mice experiments suggested that 1 combined meropenem to fight against NDM-K. pneumoniae infection in the spleen and liver. Cytotoxicity assays showed that 1 and 2 have low cytotoxicity. This study offered a new framework for the development of NDM-1 inhibitors.
- Gao, Han,Li, Jia-Qi,Kang, Peng-Wei,Chigan, Jia-Zhu,Wang, Huan,Liu, Lu,Xu, Yin-Sui,Zhai, Le,Yang, Ke-Wu
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- Ruthenium-Catalyzed Three-Component Alkylation: A Tandem Approach to the Synthesis of Nonsymmetric N,N-Dialkyl Acyl Hydrazides with Alcohols
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The borrowing hydrogen strategy has been applied in the synthesis of nonsymmetric N,N-dialkylated acyl hydrazides via a tandem three-component reaction catalyzed by a phosphine free diaminocyclopentadienone ruthenium tricarbonyl complex. This strategy represents the first direct one-pot approach to nonsymmetric functionalized acyl hydrazides. Different aromatic acyl hydrazides underwent dialkylation with a variety of primary or secondary alcohols and methanol or ethanol as alkylating agents in mild reaction conditions and good yields. Deuterium labelling experiments suggested that the primary or secondary alcohol was the hydrogen source in this tandem process. DFT calculations show that the combination of the tandem mixed product cannot be perfectly explained neither structurally nor electronically, but might be dependent of the physical state of the aldehyde or ketone intermediate (gaz vs. liquid) at the reaction temperature. (Figure presented.).
- Bettoni, Léo,Joly, Nicolas,Lohier, Jean-Fran?ois,Gaillard, Sylvain,Poater, Albert,Renaud, Jean-Luc
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supporting information
p. 4009 - 4017
(2021/07/02)
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- Method for preparing carboxylic ester compounds by oxidizing and breaking carbon-carbon bonds of secondary alcohol compounds
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The invention discloses a method for preparing carboxylic ester compounds by oxidizing and breaking carbon-carbon bonds of secondary alcohol compounds. The method comprises the following steps: adding a secondary alcohol compound, an additive and a nitrogen-doped mesoporous carbon loaded monatomic catalyst into a fatty primary alcohol solvent, putting into a pressure container, sealing, introducing oxygen source gas with a certain pressure, controlling the pressure of the oxygen source gas to be 0.1-1 MPa and the reaction temperature to be 80-150 DEG C, and obtaining a product after the reaction to be the carboxylic ester compound. The nitrogen-doped mesoporous carbon-loaded monatomic catalyst adopted by the invention is high in activity, the highest separation yield of the carboxylic ester compound as a reaction product reaches 99%, the method is wide in application range, the reaction conditions are easy to control, the catalyst can be recycled, the post-treatment is simple, and the method is suitable for industrial production.
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Paragraph 0078-0079; 0092
(2021/06/02)
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- Phosphine-free ruthenium complex-catalyzed synthesis of mono- Or dialkylated acyl hydrazides via the borrowing hydrogen strategy
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Herein, we report a diaminocyclopentadienone ruthenium tricarbonyl complex-catalyzed synthesis of mono- or dialkylated acyl hydrazide compounds using the borrowing hydrogen strategy in the presence of various substituted primary and secondary alcohols as alkylating reagents. Deuterium labeling experiments confirm that the alcohols were the hydride source in this cascade process. Density functional theory (DFT) calculations unveil the origin and the threshold between the mono- and dialkylation.
- Joly, Nicolas,Bettoni, Léo,Gaillard, Sylvain,Poater, Albert,Renaud, Jean-Luc
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p. 6813 - 6825
(2021/05/29)
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- One-pot synthesis of dimethyl succinate from D-fructose using Amberlyst-70 catalyst
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Dimethyl succinate (DMS), an important building block of bio-based platform chemicals, was produced from D-fructose under one-pot and metal-free conditions for the first time. In the presence of 1.5 mmol D-fructose, 75 mg Amberlyst-70 and 10 bar O2/
- He, Liangtu,Huang, Yuzhang,Len, Christophe,Liu, Lei,Miao, Xinge,Wang, Yantao,Yang, Weiran
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- Mild Copper-Catalyzed Addition of Arylboronic Esters to Di- tert -butyl Dicarbonate: An Easy Access to Methyl Arylcarboxylates
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An efficient copper-catalyzed addition of arylboronic esters to (Boc) 2O was developed. The reaction can be conducted under exceedingly mild conditions and is compatible with a variety of synthetically relevant functional groups. It therefore represents a useful alternative route for the synthesis of methyl arylcarboxylates. A preliminary mechanistic study indicated the involvement of an addition-elimination mechanism.
- Xu, Jin-Di,Su, Xiao-Bo,Wang, Cai,Yao, Li-Wei,Liu, Jing-Hui,Hu, Guo-Qin
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supporting information
p. 833 - 837
(2021/02/26)
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- Ultrafine Copper Oxide Particles Dispersed on Nitrogen-Doped Hollow Carbon Nanospheres for Oxidative Esterification of Biomass-Derived 5-Hydroxymethylfurfural
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One-pot synthesis of furan-2,5-dimethylcarboxylate (FDMC) from 5-hydroxymethylfurfural (HMF) is highly demanding for the commercial production of polyethylene furanoate (PEF). Herein, a direct synthesis of FDMC is reported from oxidative esterification of HMF using ultrafine CuO particles dispersed on nitrogen-doped hollow carbon nanospheres (CuO/N?C?HNSs) as a catalyst and tert-butyl hydroperoxide (TBHP) as an oxidizing and methylating reagent. The CuO/N?C?HNSs was prepared through a template protection-sacrifice strategy using SiO2 as a sacrificial template and histidine as the precursor for N and C. N-doping facilitated a strong interaction between the support and copper species, affording formation of CuO nanoparticles of less than 10 nm in size. By virtue of the highly dispersed CuO nanoparticles and a high BET surface area 373 m2/g, the CuO/N?C?HNSsshows excellent catalytic performance in the selective conversion of HMF into FDMC affording 93 % yield of the desired product with a TON value of 49. Furthermore, the oxidative esterification involving SP3C?H bond functionalization is also demonstrated using the same catalyst.
- Gupta, Shyam Sunder R.,Vinu, Ajayan,Kantam, Mannepalli Lakshmi
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p. 259 - 269
(2021/03/01)
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- Oxidative esterification of alcohols by a single-side organically decorated Anderson-type chrome-based catalyst
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The direct esterification of alcohols with non-noble metal-based catalytic systems faces great challenges. Here, we report a new chrome-based catalyst stabilized by a single pentaerythritol decorated Anderson-type polyoxometalate, [N(C4H9)4]3[CrMo6O18(OH)3C{(OCH2)3CH2OH}], which can realize the efficient transformation from alcohols to esters by H2O2oxidation in good yields and high selectivity without extra organic ligands. A variety of alcohols with different functionalities including some natural products and pharmaceutical intermediates are tolerated in this system. The chrome-based catalyst can be recycled several times and still keep the original configuration and catalytic activity. We also propose a reasonable catalytic mechanism and prove the potential for industrial applications.
- Wang, Jingjing,Jiang, Feng,Tao, Chaofu,Yu, Han,Ruhlmann, Laurent,Wei, Yongge
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supporting information
p. 2652 - 2657
(2021/04/21)
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- Process for Preparing Furan-2,5-diakylcarboxylate
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The present invention (i) provides II a process for the preparation of a (oxidation) compound represented by III the following formula, (ii) comprising reacting III a compound N- represented (N-bromosuccinimide, NBS) by the above IV formula with an alcohol; in (iii) the presence IV of a catalyst, in the presence of a catalyst to obtain a (alkoxy carbonylation) compound represented by the general I formula 2,5- (FDAC) and then reacting. the compound of the formula with an alcohol and carbon monoxide in the presence of a catalyst and a base to obtain the compound represented by the general formula (I). (by machine translation)
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Paragraph 0075-0082; 0094-0104
(2020/05/07)
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- Preparation method of furfuryl ester (by machine translation)
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The preparation method comprises the following steps: uniformly mixing furfural, an oxidation esterification catalyst, a cocatalyst and a solvent, and reacting under the condition of an oxygen source for a period of time under a certain temperature and pressure to obtain the furfuryl ester. The method is high in selectivity, few in byproducts and mild in reaction condition, and has a certain industrial application prospect. (by machine translation)
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Paragraph 0023-0056
(2020/06/22)
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- Synthesis, antifungal and antibacterial activity of calix[4]arene-based 1,3,4-oxadiazole derivatives
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We describe the synthesis of some novel p-tert-butylcalix[4]arene-based (5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate derivatives (4a–e). These compounds were synthesized by the reaction of tetra-tert-butyl calix[4]arene (1) with (5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate (3a–e) in the presence of potassium carbonate as a weak base and dry acetone as the solvent. All the newly synthesized calix[4]arene derivatives were characterized by elemental analysis and various spectroscopic methods such as FT-IR, 1H NMR,13C NMR, DEPT, and ESI-MS. The synthesized compounds were tested in vitro for their antibacterial and antifungal activities against Escherichia coli and Aspergillus fumigates in comparison with enrofloxacin and amphotericin as reference drugs, which are normally used for treating such infections. The synthesized compounds showed different inhibition zones against the tested bacteria and fungi. Compound 4c was found to be most effective against A. fumigates, whereas compound 4e was found to be equally effective against E. coli and A. fumigates.
- Dono Gezelbash, Zahra,Akbari Dilmaghani, Karim
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p. 1446 - 1452
(2020/03/11)
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- Tridentate Nickel(II)-Catalyzed Chemodivergent C-H Functionalization and Cyclopropanation: Regioselective and Diastereoselective Access to Substituted Aromatic Heterocycles
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A Schiff-base nickel(II)-phosphene-catalyzed chemodivergent C-H functionalization and cyclopropanation of aromatic heterocycles is reported in moderate to excellent yields and very good regioselectivity and diastereoselectivity. The weak, noncovalent interaction between the phosphene ligand and Ni center facilitates the ligand dissociation, generating the electronically and coordinatively unsaturated active catalyst. The proposed mechanisms for the reported reactions are in good accord with the experimental results and theoretical calculations, providing a suitable model of stereocontrol for the cyclopropanation reaction.
- Nag, Ekta,Gorantla, Sai Manoj N. V. T.,Arumugam, Selvakumar,Kulkarni, Aditya,Mondal, Kartik Chandra,Roy, Sudipta
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supporting information
p. 6313 - 6318
(2020/09/02)
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- Methoxylation of Acyl Fluorides with Tris(2,4,6-trimethoxyphenyl)phosphine via C-OMe Bond Cleavage under Metal-Free Conditions
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Acyl fluorides are subjected to methoxylation with tris(2,4,6-trimethoxyphenyl)phosphine (TMPP) to afford the corresponding methyl esters in good to excellent yields. This transformation is featured by C(sp2)-OMe bond cleavage under metal-free conditions. Unprecedented utilization of TMPP as a methoxylating agent realized the installation of an OMe group into the desired products.
- Ishida, Takumi,Nishihara, Yasushi,Wang, Xiu,Wang, Zhenhua
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p. 7526 - 7533
(2020/06/27)
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- Ni-catalyzed direct alcoholysis of N-acylpyrrole-type tertiary amides under mild conditions
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N-Acylpyrrole-type amides are a class of versatile building blocks in asymmetric synthesis. We report that by employing Ni(COD)2/2,2′-bipyridine (5 mol%) catalytic system, the direct, catalytic alcoholysis of N-acylpyrrole-type aromatic and aliphatic amides with both primary and secondary alcohols can be achieved efficiently under very mild conditions (rt, 1 h) even at gram scale. By increasing the catalyst loading to 10 mol%, prolonging reaction time (18 h), and/or elevating reaction temperature to 50 °C/80 °C, the reaction could be extended to both complex and hindered N-acylpyrroles as well as to N-acylpyrazoles, Nacylindoles, and to other (functionalized) primary and secondary alcohols. In all cases, only 1.5 equiv. of alcohol were used. The value of the method has been demonstrated by the racemization-free, catalytic alcoholysis of chiral amides yielded from other asymmetric methodologies.
- Chen, Hang,Chen, Dong-Huang,Huang, Pei-Qiang
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p. 370 - 376
(2020/03/03)
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- Catalytic conversion of ketones to esters: Via C(O)-C bond cleavage under transition-metal free conditions
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The catalytic conversion of ketones to esters via C(O)-C bond cleavage under transition-metal free conditions is reported. This catalytic process proceeds under solvent-free conditions and offers an easy operational procedure, broad substrate scope with excellent selectivity, and reaction scalability. This journal is
- Subaramanian, Murugan,Ramar, Palmurukan M.,Rana, Jagannath,Gupta, Virendra Kumar,Balaraman, Ekambaram
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supporting information
p. 8143 - 8146
(2020/09/09)
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- Ruthenium-catalyzed hydrogenation of CO2as a route to methyl esters for use as biofuels or fine chemicals
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A novel robust diphosphine-ruthenium(ii) complex has been developed that can efficiently catalyze both the hydrogenation of CO2 to methanol and its in situ condensation with carboxylic acids to form methyl esters; a TON of up to 3260 is achievable for the CO2 to methanol step. Both aromatic and aliphatic carboxylic acids can be transformed to their corresponding methyl esters with high conversion and selectivity (17 aliphatic and 18 aromatic examples). On the basis of a series of experiments, a mechanism has been proposed to account for the various steps involved in the catalytic pathway. More importantly, this approach provides a promising route for using CO2 as a C1 source for the production of biofuels, fine chemicals and methanol.
- Li, Yong,Liu, Qingbin,Ma, Yanping,Solan, Gregory A.,Sun, Wen-Hua,Wang, Zheng,Zhang, Qiuyue,Zhao, Ziwei,Zhong, Yanxia
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p. 6766 - 6774
(2020/08/25)
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- Copper-catalyzed oxidative methyl-esterification of 5-hydroxymethylfurfural using TBHP as an oxidizing and methylating reagent: A new approach for the synthesis of furan-2,5-dimethylcarboxylate
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Catalytic conversion of 5-hydroxymethylfurfural (HMF) into furan-2,5-dimethylcarboxylate (FDMC) is of great significance in the production of polyethylene furanoate (PEF), a renewable biomass-derived polymer that can replace the fossil dependent polyethylene terephthalate (PET). Herein, for the first time, we report the synthesis of FDMC from oxidative methyl-esterification of HMF using tert-butyl hydroperoxide (TBHP) as an oxidizing and methylating reagent catalyzed by mesoporous alumina nanospheres-embedded with CuO nanoparticles (CuO/m-Al2O3). The CuO/m-Al2O3 catalysts with different copper contents were prepared by evaporation-induced self-assembly of a structure-directing agent (Pluronic P-123). The decomposition of P-123 during calcination in air results into the formation of a mesoporous structure with highly dispersed CuO nanoparticles. The as-prepared 6-CuO/m-Al2O3 exhibits excellent catalytic activity towards oxidative methyl-esterification of HMF into FDMC with 92% yield and turnover frequency (TOF) of 0.56 h?1. Furthermore, oxidative methyl-esterification of a range of substrates through SP3 C[sbnd]H bond functionalization has also been demonstrated using the same catalyst.
- Gupta, Shyam Sunder R.,Kantam, Mannepalli Lakshmi,Vinu, Ajayan
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p. 259 - 269
(2020/06/27)
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- A selective oxidative valorization of biomass-derived furfural and ethanol with the supported gold catalysts
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The oxidative upgrading of renewable furfural (FUR) and ethanol is an important way to produce high-quality liquid fuel and value-added furanic derivatives. In this work, a series of supported Au catalysts were prepared using the colloid-immobilization technique, and further employed for catalytic oxidative condensation of FUR with ethanol in the presence of molecular oxygen. It is found that, with Au@CaO as the catalyst, 85.9% conversion of FUR and 81.8% selectivity of the product furan-2-acrolein were achieved in the absence of any homogeneous basic additive. The effects of different reactions such as reaction time, temperature and catalyst amount were explored in detail. Also, the influences of calcination temperature and amount of protective agent during the preparation of catalyst were investigated. According to the characterization results of catalyst, it is concluded that the synergistic effect of metallic Au and basic site of CaO support plays a significant role on the selective oxidative condensation. At last, a possible reaction mechanism is proposed based on the catalytic principle and experimental results.
- Gao, Yiqi,Tong, Xinli,Zhang, Haigang
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p. 238 - 245
(2019/06/18)
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- Facile synthesis of a highly efficient Co/Cu@NC catalyst for base-free oxidation of alcohols to esters
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The direct oxidation of alcohols to esters is an environmentally benign and cost-effective organic synthetic strategy, but it is still a great challenge to discover an economic, highly active, and long-term stable catalyst for efficient transformation of alcohols to esters under milder conditions. Herein, we developed cobalt and copper nanoparticle -co-decorated nitrogen-doped carbon catalysts (CoCu@NCn) through two steps of ball milling and calcination. It was found that CoCu@NCn could catalyze the oxidation of alcohols to esters effectively in the absence of basic additives. The catalytic activity was much higher than those of monometallic Co@NC2 and Cu@NC2 samples, and the catalyst can be conveniently recovered and quite steadily reused. Through a series of control experiments and characterizations, it is concluded that the remarkable catalytic performance of CoCu@NC2 was associated with the synergistic effect between the two metal components, the enhanced basic active sites and the active surface area.
- Jiang, Jiusheng,Li, Xiang,Du, Shengyu,Shi, Langchen,Jiang, Pingping,Zhang, Pingbo,Dong, Yuming,Leng, Yan
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p. 7780 - 7785
(2020/06/09)
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- Aldehydes as potential acylating reagents for oxidative esterification by inorganic ligand-supported iron catalysis
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The oxidative esterification of various aldehydes with alcohols could be achieved by a heterogeneous iron(iii) catalyst supported on a ring-like POM inorganic ligand under mild conditions, affording the corresponding esters, including several drug molecules and natural products, in high yields. ESI-MS and control experiments demonstrated that POM-FeV(O) was the active catalytic species and the plausible mechanism was presented. More importantly, the 6th run of the iron catalyst recycles shows only a slight decrease in the yield.
- Yu, Han,Wang, Jingjing,Wu, Zhikang,Zhao, Qixin,Dan, Demin,Han, Sheng,Tang, Jiangjiang,Wei, Yongge
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supporting information
p. 4550 - 4554
(2019/08/21)
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- A tunable precious metal-free system for selective oxidative esterification of biobased 5-(hydroxymethyl)furfural
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Oxidative esterification of biomass-derived 5-(hydroxymethyl) furfural (HMF) and furfural and their derivatives has been performed using a simple MnO2/NaCN system. The developed method allows the selective one-pot transformation of HMF to dimethyl furan-2,5-dicarboxylate (FDME) in 83% isolated yield without the formation of a free acid. Simplification of FDME production provides the missing link for manufacturing sustainable value-added materials from biomass. Addition of water to the oxidative system allows fine-tuning of reaction selectivity to obtain the previously difficult-to-access pure methyl 5-(hydroxylmethyl)furan-2-carboxylate in one step directly from the unprotected HMF without chromatographic separation.
- Kozlov, Kirill S.,Romashov, Leonid V.,Ananikov, Valentine P.
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supporting information
p. 3464 - 3468
(2019/06/24)
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- Chloride-Induced Highly Active Au Catalyst for Methyl Esterification of Alcohols
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Chloride is generally regarded as a harmful species for the heterogeneous catalysts, especially Au catalysts. In this work, a series of active Au/NiOx catalysts were successfully prepared with co-precipitation method by tracking the concentrations of chloride in the re-dispersed aqueous solutions. For methyl esterification of alcohols, the highest active Au/NiOx catalysts could be prepared from aqueous solutions containing 8-13 ppm chloride, the yield of methyl benzoate of catalyst Au/NiOx-9 was 99%. The catalyst structures and the role of chloride in catalysts were explored by ICP, BET, XPS, TEM and EXAFS characterizations. It was found that the appropriate amount of residual chloride in Au catalysts was beneficial to their catalytic activities. Especially for Au/NiOx-9, the appropriate amount of residual chloride had positive effects on the physicochemical properties of Au/NiOx catalyst, the position of Au nanoparticles (NPs) located on NiOx crystallites and the ratio of Auδ+/Au0 in catalyst, which together resulted in its high reactivity.
- Zhang, Chengming,Wang, Yongzhao
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p. 249 - 254
(2019/02/13)
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- Method of preparing methyl furoate
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The invention discloses a method of preparing methyl furoate. methyl furoate is prepared by catalyzing one-step oxidative esterification of furfural through a homogenous catalyst. The method includesthe steps of dissolving furfural in methanol, adding a c
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Paragraph 0021-0038
(2019/04/17)
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- Synthesizing method of furoate compounds
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The invention discloses a synthesizing method of furoate compounds. The synthesizing method of the furoate compounds comprises the following steps of mixing furfural, solvent and oxidizing agent inside a container at a certain temperature for reaction; after reaction is completed, adding water into the reaction system to dissolving the oxidizing agent, and then performing liquid-liquid separationto collect liquid products containing the furoate compounds. The synthesizing method of the furoate compounds is mild in reaction condition, saves catalysts of strong acids and achieves esterificationof the furfural within one step to obtain the furoate compounds, thereby being simple in operation, low in cost, green and environmentally friendly.
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Paragraph 0021-0022; 0027-0028; 0031-0032
(2019/04/17)
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- Synthesis, characterization, and nonlinear optical properties of some new series of S-(5-aryl-1,3,4-oxadiazol-2-yl) 2-chloroethanethioate derivatives
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In the present investigation, some novel S-(5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate (3a–3e) derivatives were synthesized and their impact on optical properties was studied. They have also been characterized by elemental analysis and various spectroscopic methods including FTIR, 1 H NMR, 13 C NMR, and UV-Vis techniques. The nonlinear refractive indexes of 3a–3e were also measured in dichloromethane via Z-scan method using a continuous wave diode-pumped laser at 532 nm wavelength. The nonlinear refractive coefficient of compounds was obtained from 1011 m2/W order. Regarding the appropriate nonlinearity of these compounds, they could be considered good candidates for biooptical and photonic applications. All the synthesized compounds (3a–3e) have also been evaluated for their antimicrobial and antifungal activities. The bioactive assay showed that the synthetic compounds displayed variable inhibition zones against tested bacterium Escherichia coli and fungus Aspergillus fumigatus in comparison to enrofloxacin and amphotericin as reference drugs, which are normally used for treating such infections.
- Ghezelbash, Zahra Dono,Motiei, Hamideh,Mahmoody, Miri,Dilmaghani, Karim Akbari
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p. 902 - 910
(2019/07/17)
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- Flow hydrodediazoniation of aromatic heterocycles
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Continuous flow processing was applied for the rapid replacement of an aromatic amino group with a hydride. The approach was applied to a range of aromatic heterocycles, confirming the wide scope and substituent-tolerance of the processes. Flow equipment was utilized and the process optimised to overcome the problematically-unstable intermediates that have restricted yields in previous studies relying on batch procedures. Various common organic solvents were investigated as potential hydride sources. The approach has allowed key structures, such as amino-pyrazoles and aminopyridines, to be deaminated in good yield using a purely organic-soluble system.
- R?der, Liesa,Nicholls, Alexander J.,Baxendale, Ian R.
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- AuPd-Fe3O4 Nanoparticle-Catalyzed Synthesis of Furan-2,5-dimethylcarboxylate from 5-Hydroxymethylfurfural under Mild Conditions
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Efficient one-pot oxidative esterification of 5-hydroxymethylfurfural (HMF) to furan-2,5-dimethylcarboxylate (FDMC) was achieved under extremely mild reaction conditions by using AuPd alloy nanoparticles (NPs) supported on Fe3O4. A high yield of FDMC (92 %) was obtained at room temperature under atmospheric O2. The reaction proceeded through the synergistic effects of the AuPd heterobimetallic catalyst system. The most effective molar ratio of noble metal contents for HMF oxidation was 1.00:1.18. If Au-Fe3O4 NPs were used as the catalyst, selective synthesis of 5-hydroxymethylfuroic acid methyl ester (HMFE) was achieved. Additionally, the AuPd-Fe3O4 catalyst could be successfully reused.
- Cho, Ahra,Byun, Sangmoon,Cho, Jin Hee,Kim, Byeong Moon
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p. 2310 - 2317
(2019/04/30)
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- Method for preparing carboxylic ester by alcohol direct oxidation esterification method
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The invention discloses a method for preparing a carboxylic ester by an alcohol direct oxidation esterification method. The method comprises the following steps: taking an aromatic alcohol compound ora saturated linear aliphatic alcohol as a reaction substrate, taking an Au-Co composite particle carrier as a catalyst, adding a low catalytic amount of alkali, reacting for 0.5-15 h in a methanol solvent at the temperature of 25-150 DEG C in air or oxygen or a mixed atmosphere of the air or the oxygen, and performing aftertreatment to obtain a target product carboxylic ester. According to the preparation method disclosed by the invention, the process steps are reduced, conditions are mild, catalyst consumption is less, atom economy is high, the method is simple to operate, the application range of the substrate is wide, and industrial practicability is achieved.
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Paragraph 0066; 0067
(2019/06/30)
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- Method for synthesizing methyl 2-furoate
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The invention relates to a method for synthesizing methyl 2-furoate by using furfural as a raw material and using a catalytic oxidation esterification method. According to the method, oxygen or air isused as an oxidant, and a cheap metal catalyst is used
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Paragraph 0014; 0016; 0018; 0020; 0022; 0024; 0025; 0026
(2018/07/15)
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- Development of N-Doped Carbon-Supported Cobalt/Copper Bimetallic Nanoparticle Catalysts for Aerobic Oxidative Esterifications Based on Polymer Incarceration Methods
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Heterogeneous nitrogen-doped carbon-incarcerated cobalt/copper bimetallic nanoparticle (NP) catalysts, prepared from nitrogen-containing polymers, were developed, and an efficient catalytic process for aerobic oxidative esterification was achieved in the presence of a low loading (1 mol %) of catalyst that could be reused and easily reactivated. This protocol enabled diverse conditions for the bimetallic NP formation step to be screened, and significant rate acceleration by inclusion of a copper dopant was discovered. The catalytic activity of the bimetallic Co/Cu catalysts is much higher than that for cobalt catalysts reported to date and is even comparable with noble-metal NP catalysts.
- Yasukawa, Tomohiro,Yang, Xi,Kobayashi, Shu
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supporting information
p. 5172 - 5176
(2018/09/12)
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- 1,1,2,2-Tetrahydroperoxy-1,2-Diphenylethane: An efficient and high oxygen content oxidant in various oxidative reactions
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Several oxidative approaches namely thiocyanation of aromatic compounds, epoxidation of alkenes, amidation of aromatic aldehydes, epoxidation of α β-unsaturated ketones, oxidation of sulfides to sulfoxides and sulfones, bayer-villeger reaction, bromination and iodation of aniline and phenol derivatives oxidative esterification, oxidation of pyridines and oxidation of secondary, allylic and benzyllic alcohols were carried out using 1,1,2,2-Tetrahydroperoxy-1,2-Diphenylethane as the potential solid oxidant which can be stored for several months without any loss in its activity. All of the procedures were accomplished via mild reaction conditions and the products were afforded in high yields and short reaction times.
- Khosravi, Kaveh,Naserifar, Shirin
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supporting information
p. 6584 - 6592
(2018/10/05)
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- Synthesis, characterization and catalytic performances of benzimidazolin-2-iminato actinide (IV) complexes in the Tishchenko reactions for symmetrical and unsymmetrical esters
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A new family of benzimdazolin-2-iminato actinide?(IV) complexes [(Bim7-MeDipp/MeN)An(N(SiMe3)2)3] (An = U (3), Th (4)) and [(Bim4-MeDipp/MeN)An(N(SiMe3)2)3] (An = U (5), Th (6)) were synthesized and their solid state structures were established by single-crystal X-ray diffraction analysis. The catalytic performances of complexes 3–6 towards the homo- and cross-coupling of aldehydes (Tishchenko reaction) were studied and the thorium complexes 4 and 6 displayed moderate to high activities for the production of the corresponding symmetric and unsymmetrical esters. Coupling of aldehyde and alcohols, known as the tandem proton-transfer esterification, and the intermolecular coupling reaction between aldehyde and trifluoromethylketones were also investigated by these thorium complexes, indicating a complementary method to obtain unsymmetrical esters selectively. Plausible mechanisms for these reactions are proposed based on stoichiometric studies.
- Liu, Heng,Khononov, Maxim,Fridman, Natalia,Tamm, Matthias,Eisen, Moris S.
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p. 123 - 137
(2017/10/25)
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- A regulatable oxidative valorization of furfural with aliphatic alcohols catalyzed by functionalized metal-organic frameworks-supported Au nanoparticles
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The oxidative upgrading of furfural (FUR) and aliphatic alcohols is an important way to produce desirable precursor of jet fuel or value-added furanic compound. Therein, developing a highly active catalytic system with switchable product selectivity still remains a challenge. In this work, we report a novel strategy on regulating the oxidative condensation and oxidative esterification of FUR with aliphatic alcohol in the presence of molecular oxygen. Firstly, Au@UiO-66 is prepared using different methods and employed as the catalyst for the oxidative valorization of FUR with methanol. It is found that the impregnation-reduction-H2 (I-H) method is the best where a 100% selectivity of methyl-2-furoate with a complete conversion was obtained using Au@UiO-66 as catalyst. Then, a series of metal-organic frameworks (MOFs) supported Au nanoparticles (Au@UiO-66-X) such as Au@UiO-66, Au@UiO-66-NH2, Au@UiO-66-NO2, Au@UiO-66-COOH and Au@UiO-66-NH3Cl have been prepared with I-H method and employed for oxidative valorization of furfural with ethanol. Experimental results showed that, in “FUR-ethanol-O2” system, the Au@UiO-66-X can efficiently regulate the oxidative condensation and oxidative esterification as two competitive reaction pathways. With Au@UiO-66-COOH as the catalyst, the oxidative condensation process is dominant in which 84.1% selectivity of furan-2-acrolein is attained; Meanwhile, the Au@UiO-66 is beneficial to the occurrence of oxidative esterification and generation of ethyl-2-furoate. At last, based on the catalyst characterization and the numerous control experiments, a possible catalytic reaction mechanism for conversion of FUR is proposed.
- Ning, Liangmin,Liao, Shengyun,Liu, Xuguang,Guo, Pengfei,Zhang, Zhenya,Zhang, Haigang,Tong, Xinli
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- Method for preparing methyl furoate from furfuraldehyde through oxidation and esterification
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The invention relates to a method for preparing methyl furoate from furfuraldehyde through catalyzed oxidation and esterification. According to the method, the efficient catalyzed synthesis of the methyl furoate from the furfuraldehyde through catalyzed o
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Paragraph 0011; 0012; 0014; 0016; 0018; 0020; 0022; 0024
(2018/07/15)
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- Preparation method of 5-methyl hydroxyvalerate
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The invention discloses a preparation method of 5-methyl hydroxyvalerate. According to the preparation method, a Cu-La-Al2O3 catalyst is taken as a catalyst for replacing heavy metals of Rh and Au, and the two-step reaction for preparing furfural hemimeth
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Paragraph 0036-0037
(2018/12/02)
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- Efficient synthesis of esters through oxone-catalyzed dehydrogenation of carboxylic acids and alcohols
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Since esters are important organic synthesis intermediates, an environmentally friendly oxone catalyzed-esterification of carboxylic acids with alcohols has been developed. A series of carboxylic acid esters are obtained in high yield. This strategy requires mild reaction conditions, providing an attractive alternative for the construction of valuable carbonyl esters. Electron-rich and electron-deficient groups are compatible with the standard conditions and a variety of substrates are demonstrated. Moreover, the reaction could easily be adapted to typical prodrugs, drugs and gram-scale synthesis.
- Hou, Fei,Wang, Xi-Cun,Quan, Zheng-Jun
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supporting information
p. 9472 - 9476
(2019/01/03)
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- A biocatalytic method for the chemoselective aerobic oxidation of aldehydes to carboxylic acids
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Herein, we present a study on the oxidation of aldehydes to carboxylic acids using three recombinant aldehyde dehydrogenases (ALDHs). The ALDHs were used in purified form with a nicotinamide oxidase (NOx), which recycles the catalytic NAD+ at the expense of dioxygen (air at atmospheric pressure). The reaction was studied also with lyophilised whole cell as well as resting cell biocatalysts for more convenient practical application. The optimised biocatalytic oxidation runs in phosphate buffer at pH 8.5 and at 40 °C. From a set of sixty-one aliphatic, aryl-Aliphatic, benzylic, hetero-Aromatic and bicyclic aldehydes, fifty were converted with elevated yield (up to >99%). The exceptions were a few ortho-substituted benzaldehydes, bicyclic heteroaromatic aldehydes and 2-phenylpropanal. In all cases, the expected carboxylic acid was shown to be the only product (>99% chemoselectivity). Other oxidisable functionalities within the same molecule (e.g. hydroxyl, alkene, and heteroaromatic nitrogen or sulphur atoms) remained untouched. The reaction was scaled for the oxidation of 5-(hydroxymethyl)furfural (2 g), a bio-based starting material, to afford 5-(hydroxymethyl)furoic acid in 61% isolated yield. The new biocatalytic method avoids the use of toxic or unsafe oxidants, strong acids or bases, or undesired solvents. It shows applicability across a wide range of substrates, and retains perfect chemoselectivity. Alternative oxidisable groups were not converted, and other classical side-reactions (e.g. halogenation of unsaturated functionalities, Dakin-Type oxidation) did not occur. In comparison to other established enzymatic methods such as the use of oxidases (where the concomitant oxidation of alcohols and aldehydes is common), ALDHs offer greatly improved selectivity.
- Knaus, Tanja,Tseliou, Vasilis,Humphreys, Luke D.,Scrutton, Nigel S.,Mutti, Francesco G.
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supporting information
p. 3931 - 3943
(2018/09/11)
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- Ni-Catalyzed chemoselective alcoholysis of: N -acyloxazolidinones
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Although N-acyloxazolidinone-based (catalytic) asymmetric synthetic methodologies occupy an important position in modern organic synthesis, the catalytic cleavage of a chiral auxiliary remains underdeveloped. We report the Ni(cod)2/bipyr.-catalyzed alcoholysis of N-acyloxazolidinones to deliver esters. The reaction is broad in scope for both N-acyloxazolidinone substrates and alcohol nucleophiles, and displays good functional group tolerance and excellent chemoselectivity. A gram-scale methanolysis allowed the enantioselective synthesis of the C22-C26 segment of a close analogue of the potent immunosuppressant agent FK506.
- Huang, Pei-Qiang,Geng, Hui
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supporting information
p. 593 - 599
(2018/02/14)
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- Aerobic oxidative esterification of 5-hydroxymethylfurfural to dimethyl furan-2,5-dicarboxylate by using homogeneous and heterogeneous PdCoBi/C catalysts under atmospheric oxygen
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The conversion of platform molecule 5-hydroxymethylfurfural (HMF) into many value-added derivatives has attracted significant interest. FDCA and its esters are important derivatives of HMF, which can be used as polyester monomers and pharmaceutical intermediates. In this paper, oxidative esterification of 5-HMF has been carried out by using homogeneous and heterogeneous PdCoBi/C catalysts under atmospheric oxygen. The effect of reaction conditions on product distribution has been studied under both homogeneous and heterogeneous catalytic conditions. The highest yields of oxidative esterification products are obtained at 93% and 96% by using homogeneous and heterogeneous PdCoBi/C catalysts, respectively. The catalysts are characterized by X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (XRD). The catalytic system has better compatibility according to the expansion of the substrate. A reaction mechanism is proposed, and recycle experiments are also conducted.
- Li, Feng,Li, Xing-Long,Li, Chuang,Shi, Jing,Fu, Yao
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p. 3050 - 3058
(2018/07/13)
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- Photocatalytic C–H activation and oxidative esterification using Pd@g-C3N4
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Graphitic carbon nitride supported palladium nanoparticles, Pd@g-C3N4, have been synthesized and utilized for the direct oxidative esterification of alcohols using atmospheric oxygen as a co-oxidant via photocatalytic C–H activation.
- Verma, Sanny,Nasir Baig,Nadagouda, Mallikarjuna N.,Varma, Rajender S.
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p. 248 - 252
(2017/10/05)
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- Cobalt-entrenched N-, O-, and S-tridoped carbons as efficient multifunctional sustainable catalysts for base-free selective oxidative esterification of alcohols
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We report the synthesis of sustainable and reusable non-noble transition-metal (cobalt) nanocatalysts containing N-, O-, and S-tridoped carbon nanotube (Co@NOSC) composites. The expensive and benign carrageenan served as the source of carbon, oxygen, and sulfur, whereas urea served as the nitrogen source. The material was prepared via direct mixing of precursors and freeze-drying followed by carbonization under nitrogen at 900 °C. Co@NOSC catalysts comprising a Co inner core and outer electron-rich heteroatom-doped carbon shell were thoroughly characterized using various techniques, namely, TEM, HRTEM, STEM elemental mapping, XPS, BET, and ICP-MS. The utility of the Co@NOSC catalyst was explored for base-free selective oxidative esterification of alcohols to the corresponding esters under mild reaction conditions; excellent conversions (up to 97%) and selectivities (up to 99%) were discerned. Furthermore, the substrate scope was explored for the cross-esterification of benzyl alcohol with long-chain alcohols (up to 98%) and lactonization of diols (up to 68%). The heterogeneous nature and stability of the catalyst facilitated by its ease of separation for long-term performance and recycling studies showed that the catalyst was robust and remained active even after six recycling experiments. EPR measurements were performed to deduce the reaction mechanism in the presence of POBN (α-(4-pyridyl-1-oxide)-N-tert-butylnitrone) as a spin-trapping agent, which confirmed the formation of CH2OH radicals and H radicals, wherein the solvent plays an active role in a nonconventional manner. A plausible mechanism was proposed for the oxidative esterification of alcohols on the basis of EPR findings. The presence of a cobalt core along with cobalt oxide and the electron-rich N-, O-, and S-doped carbon shell displayed synergistic effects to afford good to excellent yields of products.
- Nandan, Devaki,Zoppellaro, Giorgio,Med?ík, Ivo,Aparicio, Claudia,Kumar, Pawan,Petr, Martin,Tomanec, Ond?ej,Gawande, Manoj B.,Varma, Rajender S.,Zbo?il, Radek
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p. 3542 - 3556
(2018/08/07)
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- Amberlyst-15 catalysed oxidative esterification of aldehydes using a H2O2 trapped oxidant as a terminal oxidant
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A simple and efficient method has been developed for the selective oxidative esterification of aldehydes using commercially available Amberlyst-15 as a catalyst. H2O2 released from a clathrate structured 4Na2SO4·2H2O2·NaCl oxidant serves as an efficient source of terminal oxidants. Various aromatic, heteroaromatic, and aliphatic aldehydes undergo selective esterification to give good to excellent yield. The heterogeneous catalyst, Amberlyst-15, exhibits high reactivity and can be recycled over several runs. The 4Na2SO4·2H2O2·NaCl oxidant was found to be superior to commonly used oxidizing agents providing an anhydrous, easy to handle and stable form of H2O2
- Gayakwad, Eknath M.,Patil, Vilas V.,Shankarling, Ganapati S.
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p. 2695 - 2701
(2017/04/03)
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- Direct oxidation of aldehydes to methyl esters with urea hydrogen peroxide and p-toluenesulfonyl chloride
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Combination of urea hydrogen peroxide and p-toluenesulfonyl chloride in methanol was proved to be facile and highly efficient for the oxidative methyl esterification of various aldehydes to the corresponding carboxylic methyl esters.
- Jeong, Deuk Jun,Lee, Su Bin,Lee, Jong Chan
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p. 725 - 728
(2017/12/28)
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- Solvent- and Metal-free Oxidative Esterification of Aromatic Aldehydes Using Urea-2,2-dihydroperoxypropane as a New Solid Oxidant
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Urea-2,2-dihydroperoxypropane as a noble and solid gem-dihydroperoxide derivative was used to transform various aromatic aldehydes to their corresponding benzoate derivatives in the presence of HBr under mild conditions at room temperature in high yields and short reaction times.
- Khosravi, Kaveh,Khalaji, Kobra,Naserifar, Shirin
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p. 303 - 309
(2017/03/27)
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- Facile Coupling of Aldehydes with Alcohols: An Evolved Tishchenko Process for the Preparation of Unsymmetrical Esters
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A facile coupling process between aldehydes and alcohols to afford unsymmetrical esters is presented herein. This transformation is complementary to the Tishchenko reaction and provides access to unsymmetrical esters under very mild conditions. Various aldehydes and alcohols are suitable in this reaction, and the addition of a sacrificial trifluoromethyl ketone allows the process to take place in a highly selective manner. A plausible mechanism based on details obtained by monitoring the reaction progress and deuterium-labeling studies has been proposed.
- Liu, Heng,Eisen, Moris S.
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p. 4852 - 4858
(2017/09/07)
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