591-81-1Relevant academic research and scientific papers
Platinum(II) Catalysed Selective Remote Oxidation of Unactivated C-H Bonds in Aliphatic Carboxylic Acids
Kao, Lien-Chung,Sen, Ayusman
, p. 1242 - 1243 (1991)
Platinum(II) ion, in the presence of platinum(IV), is found to catalyse the hydroxylation of unactivated C-H bonds of aliphatic carboxylic acids in water with the following order of reactivity: α-C-H δ-C-H ca. ε-C-H.
Nicotinamide Adenine Dinucleotide-Dependent Redox-Neutral Convergent Cascade for Lactonizations with Type II Flavin-Containing Monooxygenase
Huang, Lei,Romero, Elvira,Ressmann, Anna K.,Rudroff, Florian,Hollmann, Frank,Fraaije, Marco W.,Kara, Selin
, p. 2142 - 2148 (2017)
A nicotinamide adenine dinucleotide (NADH)-dependent redox-neutral convergent cascade composed of a recently discovered type II flavin-containing monooxygenase (FMO?E) and horse liver alcohol dehydrogenase (HLADH) has been established. Two model reaction cascades were analyzed for the synthesis of γ-butyrolactone and chiral bicyclic lactones. In the former cascade, all substrates were converted into one single product γ-butyrolactone with high atom efficiency. More than 130 mM γ-butyrolactone were obtained when applying 100 mM cyclobutanone and 50 mM 1,4-butanediol in this cascade. In the second cascade where bicyclo[4.2.0]octan-7-one and cis-1,2-cyclohexanedimethanol were coupled, the ketone substrate was converted to the corresponding normal lactone with an ee value of 89–74% (3aS, 7aS) by FMO?E alone and the abnormal lactone with an ee value of >99% (3aR, 7aS) was formed by both HLADH and FMO?E. (Figure presented.).
Di-(benzimidazole)-1, 2, 3-triazole derivative as well as preparation and application thereof in inflammatory dermatosis
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Paragraph 0058-0060; 0075-0077, (2021/06/23)
The invention belongs to the technical field of drug small molecules, and particularly discloses a brand-new di-(benzimidazole)-1, 2, 3-triazole derivative as well as preparation and application of the brand-new di-(benzimidazole)-1, 2, 3-triazole derivative. The research finds that the brand new compound has an excellent drug effect and low toxic and side effects on the aspect of inflammatory dermatosis, and has a good application prospect in the aspect of drug development of the inflammatory dermatosis.
PtII-Catalyzed Hydroxylation of Terminal Aliphatic C(sp3)?H Bonds with Molecular Oxygen
Janssen, Michiel,De Vos, Dirk E.
supporting information, p. 10724 - 10734 (2019/07/15)
The practical application of Shilov-type Pt catalysis to the selective hydroxylation of terminal aliphatic C?H bonds remains a formidable challenge, due to difficulties in replacing PtIV with a more economically viable oxidant, particularly O2. We report the potential of employing FeCl2 as a suitable redox mediator to overcome the kinetic hurdles related to the direct use of O2 in the Pt reoxidation. For the selective conversion of butyric acid to γ-hydroxybutyric acid (GHB), a significantly enhanced catalyst activity and stability (turnover numbers (TON)>30) were achieved under 20 bar O2 in comparison to current state-of-the-art systems (TON0 was prevented by the addition of monodentate pyridine derivatives, such as 2-fluoropyridine, but also by introducing varying partial pressures of N2 in the gaseous atmosphere. Finally, stability tests revealed the involvement of PtII and FeCl2 in catalyzing the non-selective overoxidation of GHB. Accordingly, in situ esterification with boric acid proved to be a suitable strategy to maintain enhanced selectivities at much higher conversions (TON>60). Altogether, a useful catalytic system for the selective hydroxylation of primary aliphatic C?H bonds with O2 is presented.
Characterization of carboxylic acid reductases for biocatalytic synthesis of industrial chemicals
Kramer, Levi,Hankore, Erome Daniel,Liu, Yilan,Liu, Kun,Jimenez, Esteban,Guo, Jiantao,Niu, Wei
, p. 1452 - 1460 (2018/10/20)
Carboxylic acid reductases (CARs) catalyze the reduction of a broad range of carboxylic acids into aldehydes, which can serve as common biosynthetic precursors to many industrial chemicals. This work presents the systematic biochemical characterization of five carboxylic acid reductases from different microorganisms, including two known and three new ones, by using a panel of short-chain dicarboxylic acids and hydroxy acids, which are common cellular metabolites. All enzymes displayed broad substrate specificities. Higher catalytic efficiencies were observed when the carbon chain length, either of the dicarboxylates or of the terminal hydroxy acids, was increased from C2 to C6. In addition, when substrates of the same carbon chain length are compared, carboxylic acid reductases favor hydroxy acids over dicarboxylates as their substrates. Whole-cell bioconversions of eleven carboxylic acid substrates into the corresponding alcohols were investigated by coupling the CAR activity with that of an aldehyde reductase in Escherichia coli hosts. Alcohol products were obtained in yields ranging from 0.5 % to 71 %. The de novo stereospecific biosynthesis of propane-1,2-diol enantiomer was successfully demonstrated with use of CARs as the key pathway enzymes. E. coli strains accumulated 7.0 mm (R)-1,2-PDO (1.0 % yield) or 9.6 mm (S)-1,2-PDO (1.4 % yield) from glucose. This study consolidates carboxylic acid reductases as promising enzymes for sustainable synthesis of industrial chemicals.
Fatty acid decarboxylation reaction kinetics and pathway of co-conversion with amino acid on supported iron oxide catalysts
Bian, Junjie,Wang, Yue,Zhang, Qi,Fang, Xudong,Feng, Lijuan,Li, Chunhu
, p. 47279 - 47287 (2017/10/19)
Fe2O3/Al-MCM-41 nanocomposite catalysts were designed and fabricated to upgrade microalgae hydrothermal liquefaction (HTL)-derived biocrude and its model compounds (palmitic acid and glutamic acid) in the absence of hydrogen. The Fe
Hydrogenation of γ-Butyrolactone to 1,4-Butanediol over CuCo/TiO2 Bimetallic Catalysts
Huang, Zhiwei,Barnett, Kevin J.,Chada, Joseph P.,Brentzel, Zachary J.,Xu, Zhuoran,Dumesic, James A.,Huber, George W.
, p. 8429 - 8440 (2017/12/08)
Titania-supported monometallic and bimetallic Cu-Co catalysts were prepared using (co)impregnation and studied for the hydrogenation of γ-butyrolactone (GBL) to 1,4-butanediol (BDO) at temperatures from 100 to 180 °C and a hydrogen pressure of 3.4 MPa. The highest catalytic activity occurred at a Cu:Co atomic ratio of 1:9 (Cu0.1Co0.9/TiO2), and a 95% yield of BDO was obtained. Characterization results showed mainly small nanoparticles (average size 2.6 nm) for pure Cu/TiO2, large particles (~19.8 nm) for pure Co/TiO2, and a bimodal particle size distribution of both small (~2.3 nm) and large (~16.5 nm) particles for the bimetallic catalyst with a Cu:Co ratio of 1:1. The addition of ~10 mol % Cu to Co/TiO2 increased the reducibility of the Co and resulted in the formation of core-shell CuCo bimetallic nanoparticles with a Co-rich core and Cu-rich shell. GBL hydrogenation in liquid ethanol and water produced an ester (ethyl 4-hydroxybutanoate) and a carboxylic acid (4-hydroxybutanoic acid) as the major products, respectively. GBL hydrogenation in 1,4-dioxane likely went through a 2-hydroxytetrahydrofuran (2-HTHF) intermediate. The 2-HTHF underwent facile ring-opening tautomerization to 4-hydroxybutanal (4-HB), followed by rapid hydrogenation to BDO at a reaction rate up to 700 times faster than GBL hydrogenation. The Cu0.1Co0.9/TiO2 catalyst maintained the BDO selectivity and about 80% of initial activity for GBL hydrogenation after 150 h time on stream in a continuous flow reactor.
Production of martite nanoparticles with high energy planetary ball milling for heterogeneous Fenton-like process
Rahmani, Amir,Khataee, Alireza,Kaymak, Baris,Vahid, Behrouz,Fathinia, Mehrangiz,Dindarsafa, Mahsa
, p. 81219 - 81230 (2016/09/09)
Natural martite microparticles (NMMs) were prepared with a high energy planetary ball mill to form a nanocatalyst for a Fenton-like process. Martite nanoparticles (MNs) of different scales are formed when the milling time ranges from 1 to 5 h at the milling speed of 300 rpm. The catalytic performances of MNs are higher than the NMMs for the degradation of acid blue 5 (AB5) in a heterogeneous Fenton-like process. The NMMs and the MNs were characterized by SEM, EDX, BET, XRD and FT-IR analyses. The size distribution of the 5 h milled martite nanoparticles (MN3) is in the range of 20 nm to 100 nm, and these have the highest surface area (19.23 m2 g-1). The influence of the main operational parameters, including initial pH, MN3 dosage, H2O2 and initial dye concentration, were investigated on the AB5 degradation. The treatment process obeys pseudo first order kinetics and some of the degradation intermediates were recognized by the GC-MS method. The environmentally-friendly production of the MNs, low amount of leached iron and repeated catalyst usage are the significant advantages of this research. Finally, an artificial neural network (ANN) is expanded to estimate the degradation efficiency of AB5 on the basis of the experimental results, which indicates the appropriate performance (R2 = 0.955).
PdPb-Catalyzed decarboxylation of proline to pyrrolidine: Highly selective formation of a biobased amine in water
Verduyckt, Jasper,Van Hoof, Maarten,De Schouwer, Free,Wolberg, Marike,Kurttepeli, Mert,Eloy, Pierre,Gaigneaux, Eric M.,Bals, Sara,Kirschhock, Christine E.A.,De Vos, Dirk E.
, p. 7303 - 7310 (2018/05/23)
Amino acids have huge potential as platform chemicals in the biobased industry. Pd-catalyzed decarboxylation is a very promising route for the valorization of these natural compounds derived from protein waste or fermentation. We report that the highly abundant and nonessential amino acid L-proline is very reactive in the Pd-catalyzed decarboxylation. Full conversions are obtained with Pd/C and different Pd/MeOx catalysts; this allowed the identification of the different side reactions and the mapping of the reaction network. Due to the high reactivity of pyrrolidine, the selectivity for pyrrolidine was initially low. By carefully modifying Pd/ZrO2 with Pb in a controlled mannervia two incipient wetness impregnation stepsthe selectivity increased remarkably. Finally, a thorough investigation of the reaction parameters resulted in an increased activity of this modified catalyst and an even further enhanced selectivity under a low H2 pressure of 4 bar at 235 °C in water. This results in a very selective and sustainable production route for the highly interesting pyrrolidine.
Catalytic pyrolysis of cellulose in ionic liquid [bmim]OTf
Qu, Guangfei,He, Weiwei,Cai, Yingying,Huang, Xi,Ning, Ping
, p. 390 - 396 (2016/05/19)
This study discussed the catalytic cracking process of cellulose in ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim]OTF) under 180 °C, 240 °C and 340 °C, found that [bmim]OTF is an effective catalyst which can effectively reduce the pyrolysis temperature(nearly 200 °C) of the cellulose. FRIR, XRD and SEM were used to analyze the structure characterization of fiber before and after the cracking; GC-MS was used for liquid phase products analysis; GC was used to analyze gas phase products. The results showed that the cellulose pyrolysis in [bmim]OTf mainly generated CO2, CO and H2, also generated 2-furfuryl alcohol, 2,5-dimethyl-1,5-diallyl-3-alcohol, 1,4-butyrolactone, 5-methyl furfural, 4-hydroxy butyric acid, vinyl propionate, 1-acetoxyl group-2-butanone, furan formate tetrahydrofuran methyl ester liquid product, and thus simulated the evolution mechanism of cellulose pyrolysis products based on the basic model of cellulose monomer.
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