3857-25-8Relevant articles and documents
Selective aldehyde reductions in neutral water catalysed by encapsulation in a supramolecular cage
Paul, Avishek,Shipman, Michael A.,Onabule, Dolapo Y.,Sproules, Stephen,Symes, Mark D.
, p. 5082 - 5090 (2021)
The enhancement of reactivity inside supramolecular coordination cages has many analogies to the mode of action of enzymes, and continues to inspire the design of new catalysts for a range of reactions. However, despite being a near-ubiquitous class of reactions in organic chemistry, enhancement of the reduction of carbonyls to their corresponding alcohols remains very much underexplored in supramolecular coordination cages. Herein, we show that encapsulation of small aromatic aldehydes inside a supramolecular coordination cage allows the reduction of these aldehydes with the mild reducing agent sodium cyanoborohydride to proceed with high selectivity (ketones and esters are not reduced) and in good yields. In the absence of the cage, low pH conditions are essential for any appreciable conversion of the aldehydes to the alcohols. In contrast, the specific microenvironment inside the cage allows this reaction to proceed in bulk solution that is pH-neutral, or even basic. We propose that the cage acts to stabilise the protonated oxocarbenium ion reaction intermediates (enhancing aldehyde reactivity) whilst simultaneously favouring the encapsulation and reduction of smaller aldehydes (which fit more easily inside the cage). Such dual action (enhancement of reactivity and size-selectivity) is reminiscent of the mode of operation of natural enzymes and highlights the tremendous promise of cage architectures as selective catalysts.
Investigation of the Hydrogenation of 5-Methylfurfural by Noble Metal Nanoparticles in a Microcapillary Reactor
Gmeiner, Julia,Seibicke, Max,Behrens, Silke,Spliethoff, Bernd,Trapp, Oliver
, p. 583 - 587 (2016)
On-column reaction gas chromatography (ocRGC) was successfully utilized as high-throughput platform for monitoring of the conversion and selectivity of hydrogenation of 5-methylfurfural catalyzed by polymer-stabilized Ru and Pd nanoparticles. We were able to elucidate the effect of various reaction conditions, mainly together with the catalyst loading on the conversion rate and the selectivity of the reaction. Our strategy yields significant improvements in reaction analysis times and cost effectiveness in comparison to standard methods. We are able to demonstrate that ocRGC approach provides valuable information about the reaction system that gives scientists a tool to design suitable catalytic systems for enhanced sustainable chemistry in the future. Capillary catalysis: A high-throughput study of the hydrogenation of 5-methylfurfural catalyzed by polymer-stabilized noble metal nanoparticles employing on-column reaction gas chromatography (ocRGC) as high-throughput platform to monitor several reaction pathways and intermediates is presented. The ocRGC approach is shown to provide valuable information about the reaction system that gives scientists a tool to design sustainable catalytic systems.
Untangling the active sites in the exposed crystal facet of zirconium oxide for selective hydrogenation of bioaldehydes
Devi, Mayanglambam Manolata,Kansal, Sushil Kumar,Kumar, Sahil,Saravanamurugan, Shunmugavel
, p. 7016 - 7026 (2020)
The present study reports the influence of the crystal phase, facets, and active sites of zirconium oxide (ZrO2) on the conversion of bio-aldehydes to their corresponding alcohols in isopropanol under mild reaction conditions. Various ZrO2-based catalysts, having different compositions of monoclinic and tetragonal crystal phases, are successfully prepared in the presence of a base via a solvothermal process. From the detailed characterization through XRD, TEM, CO2-TPD, XPS, AES, BET and poisoning studies, M-ZrO2-U-N, synthesized using zirconium oxynitrate and urea as a precursor and precipitant, respectively, in water, possesses a 100% monoclinic crystal phase with a maximum amount of exposed (-111) facets and surface oxygen concentration along with the highest number of basic sites. The catalytic study on the transformation of furfural (FFA) into furfuryl alcohol (FOH) reveals that M-ZrO2-U-N exhibits the best efficiency with a nearly quantitative yield of FOH. On the other hand, T-ZrO2-U-N, synthesized using zirconium oxynitrate and urea as a precursor and precipitant, respectively, in methanol, is found to have a 94.4% tetragonal phase and a 2.2-fold lower number of basic sites in comparison with M-ZrO2-U-N. The catalytic result with T-ZrO2-U-N displays the lowest activity in terms of the FOH yield (8.1%). According to the comparative and systematic catalytic studies with the various ZrO2 catalysts having different amounts of tetragonal and monoclinic phases, the ZrO2 catalyst having a more monoclinic phase with more exposed (-111) facets, basic sites, surface oxygen species and surface area is found to be crucial for the FFA conversion to FOH with high selectivity. M-ZrO2-U-N is found to be stable and recyclable and also shows excellent activity towards the transformation of other bio-aldehydes and ketones into their corresponding alcohols. This journal is
Cu1-Cu0 bicomponent CuNPs@ZIF-8 for highly selective hydrogenation of biomass derived 5-hydroxymethylfurfural
Feng, Yunchao,Yan, Guihua,Wang, Ting,Jia, Wenlong,Zeng, Xianhai,Sperry, Jonathan,Sun, Yong,Tang, Xing,Lei, Tingzhou,Lin, Lu
, p. 4319 - 4323 (2019)
99% yield of 2,5-dihydroxymethylfuran (DHMF) was achieved from biomass derived 5-hydroxymethylfurfural (HMF) with novel CuNPs@ZIF-8 using a relatively low hydrogen pressure and short reaction time. The activation energy of transformation of HMF to DHMF is only 39 kJ mol-1 and the TOF value reached is 21 h-1. The coexistence of Cu1 and Cu0 in Cu species is demonstrated to contribute to the high activity for the hydrogenation of HMF to DHMF.
Catalytic in-situ hydrogenation of 5-hydroxymethylfurfural to 2,5-dimethylfuran over Cu-based catalysts with methanol as a hydrogen donor
Zhang, Zihao,Wang, Changxue,Gou, Xin,Chen, Hao,Chen, Kequan,Lu, Xiuyang,Ouyang, Pingkai,Fu, Jie
, p. 245 - 250 (2019)
A series of Cu-based catalysts with different supports were synthesized and studied for the in situ hydrogenation of 5-hydroxymethylfurfural (5-HMF) to dimethylfuran (DMF) using methanol as an economical hydrogen donor. The structures and properties of the four catalysts (Cu/Al2O3, Cu/ZnO, Cu/ZrO2, and Cu/CeO2) were characterized using X-ray diffraction (XRD), temperature-programmed reduction (H2-TPR), and temperature-programmed desorption of ammonia (NH3-TPD). The experimental results showed that the use of different supports for the Cu-based catalysts significantly influenced their activity for both H2 production from methanol and hydrogenation of 5-HMF. The catalyst Cu/Al2O3 showed the best catalytic activity, which can be attributed to the highest activity for the in situ H2 production from methanol, smallest Cu crystallite size, and strongest acidity. The effects of the substrate concentration, catalyst loading, and reaction temperature and time on the in situ hydrogenation of 5-HMF were systematically investigated to determine the optimum reaction conditions.
Addressing the Metabolic Stability of Antituberculars through Machine Learning
Stratton, Thomas P.,Perryman, Alexander L.,Vilchèze, Catherine,Russo, Riccardo,Li, Shao-Gang,Patel, Jimmy S.,Singleton, Eric,Ekins, Sean,Connell, Nancy,Jacobs, William R.,Freundlich, Joel S.
, p. 1099 - 1104 (2017)
We present the first prospective application of our mouse liver microsomal (MLM) stability Bayesian model. CD117, an antitubercular thienopyrimidine tool compound that suffers from metabolic instability (MLM t1/2 1/2 values greater than or equal to 60 min. It is noteworthy that whole-cell efficacy and lack of relative mammalian cell cytotoxicity could not be predicted simultaneously. These results support the utility of our new MLM stability model in chemical tool and drug discovery optimization efforts.
Metal Catalyst and Hydrogen Gas-Free Selective Reduction of Biomass-Derived Substituted Furfuraldehyde to Alkyl Furan as a Key Biofuel Additive
Chauhan, Arvind Singh,Kumar, Ajay,Das, Pralay
, p. 892 - 899 (2021)
A metal catalyst and a hydrogen gas-free approach has been developed for selective reduction of aldehyde to an alkyl group of different substituted furan compounds. In this process, hydrazine hydrate under basic conditions at reflux temperature selectively participated in the reduction of the aldehyde moiety to the corresponding alkyl group of highly reactive furan compounds in a selective manner. The developed protocol was applied for selective and scalable reduction of 5-hydroxymethylfurfural (5-HMF) up to 250 g to 5-methylfurfuryl alcohol (MFA) in a 70% yield. Under the same process, furfuraldehyde was also tested in a 250 g reaction for 2-methylfuran (MF) synthesis in a highly selective manner and the product was distilled out from a single-pot reaction with gas chromatography (GC) purity ≥90%. The scope of the process was further extended for different substituted furfuraldehydes successfully. In addition, the protocol is found to be efficient for scalable production and easy separation of the product.
METAL CATALYST AND HYDROGEN GAS FREE APPROACHES FOR SELECTIVE REDUCTION OF ALDEHYDE TO METHYL GROUP OF DIFFERENT SUBSTITUTED FURANS
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Page/Page column 15-16, (2021/08/27)
The present invention relates to 5-methyl substituted furan compounds of general formula (I) and process for the preparation thereof: OR1R2 R3CH3(I) Particularly, the present invention relates to a metal catalyst and hydrogen gas free, atom-economy, highly selective and low-cost process for the preparation of methyl substituted furan compounds from different aldehyde substituted furan compounds.
Magnetic gold-cobalt composite catalyst as well as preparation method and application thereof
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Paragraph 0101-0106, (2021/08/25)
The invention provides a magnetic gold-cobalt composite catalyst and a preparation method and application thereof, and belongs to the technical field of catalysts. The magnetic cobalt-cobalt composite catalyst comprises a magnetic cobalt oxide carrier and a gold-cobalt alloy loaded on the surface of the magnetic cobalt oxide carrier. The chemical composition of the magnetic cobalt oxide carrier is CoO. x , 1 _AOMARKENCODTX0AOA x _AOMARKENCODELTA AOA 1.5. In the catalyst provided by the invention, a metal synergistic effect is generated between gold and cobalt in the gold-cobalt alloy. CoOx A large number of surface defects are found in the invention, and a large number of reaction active sites are provided. The catalytic activity of the catalyst for 5 -hydroxymethylfurfural hydrogenation preparation 2, 5 -dimethylfuran is improved, the conversion rate 5 - hydroxymethylfurfural is high, 2,5 -dimethylfuran is high in yield and selectivity.
