4485-09-0Relevant articles and documents
Integration of chemical catalysis with extractive fermentation to produce fuels
Anbarasan, Pazhamalai,Baer, Zachary C.,Sreekumar, Sanil,Gross, Elad,Binder, Joseph B.,Blanch, Harvey W.,Clark, Douglas S.,Dean Toste
, p. 235 - 239 (2012)
Nearly one hundred years ago, the fermentative production of acetone by Clostridium acetobutylicum provided a crucial alternative source of this solvent for manufacture of the explosive cordite. Today there is a resurgence of interest in solventogenic Clostridium species to produce n-butanol and ethanol for use as renewable alternative transportation fuels. Acetone, a product of acetone-n-butanol-ethanol (ABE) fermentation, harbours a nucleophilic α-carbon, which is amenable to C-C bond formation with the electrophilic alcohols produced in ABE fermentation. This functionality can be used to form higher-molecular-mass hydrocarbons similar to those found in current jet and diesel fuels. Here we describe the integration of biological and chemocatalytic routes to convert ABE fermentation products efficiently into ketones by a palladium-catalysed alkylation. Tuning of the reaction conditions permits the production of either petrol or jet and diesel precursors. Glyceryl tributyrate was used for the in situ selective extraction of both acetone and alcohols to enable the simple integration of ABE fermentation and chemical catalysis, while reducing the energy demand of the overall process. This process provides a means to selectively produce petrol, jet and diesel blend stocks from lignocellulosic and cane sugars at yields near their theoretical maxima.
Rh-Catalyzed Coupling of Aldehydes with Allylboronates Enables Facile Access to Ketones
Zhang, Kezhuo,Huang, Jiaxin,Zhao, Wanxiang
supporting information, (2022/02/21)
We present herein a novel strategy for the preparation of ketones from aldehydes and allylic boronic esters. This reaction involves the allylation of aldehydes with allylic boronic esters and the Rh-catalyzed chain-walking of homoallylic alcohols. The key to this successful development is the protodeboronation of alkenyl borylether intermediate via a tetravalent borate anion species in the presence of KHF2 and MeOH. This approach features mild reaction conditions, broad substrate scope, and excellent functional group tolerance. Mechanistic studies also supported that the tandem allylation and chain-walking process were involved.
Rhodium-Catalyzed Remote Isomerization of Alkenyl Alcohols to Ketones
Dong, Wenke,Yang, Hongxuan,Yang, Wen,Zhao, Wanxiang
supporting information, (2020/02/28)
We develop herein an efficient rhodium-catalyzed remote isomerization of aromatic and aliphatic alkenyl alcohols into ketones. This catalytic process, with a commercially available catalyst and ligand ([RhCl(cod)]2 and Xantphos), features high efficiency, low catalyst loading, good functional group tolerance, a broad substrate scope, and no (sub)stoichiometric additive. Preliminary mechanistic studies suggest that this transformation involves an iterative dissociative β-hydride elimination-migration insertion process.
Methods to produce fuels
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Page/Page column 54; 55; 56, (2018/02/28)
The present disclosure generally relates to the catalytic conversion of alcohols into hydrocarbon ketones suitable for use as fuels. More specifically, the present disclosure relates to the catalytic conversion of a mixture of isopropanol-butanol-ethanol (IBE) or acetone-butanol-ethanol (ABE), into ketones suitable for use as fuels. The ABE or IBE mixtures may be obtained from the fermentation of biomass or sugars.
ABE Condensation over Monometallic Catalysts: Catalyst Characterization and Kinetics
Goulas, Konstantinos A.,Gunbas, Gorkem,Dietrich, Paul J.,Sreekumar, Sanil,Grippo, Adam,Chen, Justin P.,Gokhale, Amit A.,Toste, F. Dean
, p. 677 - 684 (2017/02/26)
Herein, we present work on the catalyst development and the kinetics of acetone-butanol-ethanol (ABE) condensation. After examining multiple combinations of metal and basic catalysts reported in the literature, Cu supported on calcined hydrotalcites (HT) was found to be the optimal catalyst for the ABE condensation. This catalyst gave a six-fold increase in reaction rates over previously reported catalysts. Kinetic analysis of the reaction over CuHT and HT revealed that the rate-determining step is the C?H bond activation of alkoxides that are formed from alcohols on the Cu surface. This step is followed by the addition of the resulting aldehydes to an acetone enolate formed by deprotonation of the acetone over basic sites on the HT surface. The presence of alcohols reduces aldol condensation rates, as a result of the coverage of catalytic sites by alkoxides.
Catalytic alkylation of acetone with ethanol over Pd/carbon catalysts in flow-through system via borrowing hydrogen route
Novodárszki, Gyula,Onyestyák, Gy?rgy,Wellisch, ágnes Farkas,Pilbáth, Aranka
, p. 251 - 257 (2016/07/06)
Consecutive alkylation of acetone with ethanol as model reactants was studied in order to obtain biomass based fuels by continuous processing of acetone-butanol-ethanol (ABE) mixture. Butanol, which can inevitably form as Guerbet side product in a self-aldol reaction of ethanol was not applied in our study as an initial component, in order to follow the complexity of the reaction mechanism. A flow-through reactor was applied with inert He or reducing H2 stream in the temperature range of 150-350°C. Efficient catalysts containing Pd and base (K3PO4 or CsOH) crystallites were prepared applying commercial activated carbon (AC) support. The catalyst beds were pre-treated in H2 flow at 350°C. Mono- or dialkylated ketones were formed with high yields and these products could be reduced only to alcohols over palladium.
Highly Efficient Oxidation of Secondary Alcohols to Ketones Catalyzed by Manganese Complexes of N4 Ligands with H2O2
Shen, Duyi,Miao, Chengxia,Xu, Daqian,Xia, Chungu,Sun, Wei
supporting information, p. 54 - 57 (2015/07/28)
The manganese complex Mn(S-PMB)(CF3SO3)2 was proven to be highly efficient in the catalytic oxidation of several benzylic and aliphatic secondary alcohols with H2O2 as the oxidant and acetic acid as the additive. A maximum turnover number of 4700 was achieved in the alcohol oxidation. In addition, the Hammett analysis unveiled the electrophilic nature of this manganese catalyst with N4 ligand. (Chemical Equation Presented).
4-CH3CONH-TEMPO/Peracetic Acid System for a Shortened Electron-Transfer-Cycle-Controlled Oxidation of Secondary Alcohols
Zhang, Shufang,Miao, Chengxia,Xia, Chungu,Sun, Wei
, p. 1865 - 1870 (2015/06/23)
We have developed a 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) derivative catalyzed oxidation of secondary alcohols with peracetic acid as the oxidant, which was generated from H2O2 and acetic acid catalyzed by strongly acidic resins. The oxidation of alcohols proceeded well through a shortened electron-transfer cycle under metal-free conditions, avoiding the use of any other electron-transfer mediators such as halides. In addition, we demonstrated that the present system exhibited excellent efficiency under mild conditions for the oxidation of aromatic, aliphatic, and allylic secondary alcohols. Shortcut to ketones: The 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-derivative-catalyzed oxidation of secondary alcohols employing peracetic acid generated from H2O2 and acetic acid with strongly acidic resins proceeds through a shortened electron-transfer cycle without halide additives. The system not only exhibits excellent efficiency at room temperature but also has a wide substrate scope.
Acetone alkylation with ethanol over multifunctional catalysts by a borrowing hydrogen strategy
Onyestyák, Gy.,Novodárszki, Gy.,Barthos,Klébert, Sz.,Wellisch, á. Farkas,Pilbáth
, p. 99502 - 99509 (2015/12/04)
Step by step alkylation of acetone (A) with ethanol (E) in a ratio of 1: 2 was investigated. A fixed bed flow-through reactor system was used at a total pressure of 21 bar and in the temperature range of 150-350 °C in inert He or a reducing H2 medium. Following the hydrogen borrowing methodology, two types of catalysts were prepared; using neutral activated carbon (AC) and alkaline hydrotalcite (HT) supports, namely 5 wt% Pd/AC in the presence of alkaline additives (10, 20 and 30 wt% KOH or 20% K3PO4); 9 wt% Cu/HT and 5 wt% Pd/HT. The catalysts were activated in a H2 flow at 350 °C. Different yields of mono- or dialkylated ketones were observed. In a hydrogen medium over the same catalyst systems the ketone products could be reduced to alcohols. In this study the Pd/HT catalyst seems to be the most promising for fuel production based on biomass fermentation.
Aerobic oxidation of secondary alcohols using NHPI and iron salt as catalysts at room temperature
Zhao, Hanqing,Sun, Wei,Miao, Chengxia,Zhao, Quanyi
, p. 62 - 67 (2014/07/08)
Aerobic oxidation of various alcohols has been accomplished by using a novel catalytic system, N-hydroxyphthalimide (NHPI) combined with Fe(NO 3)3·9H2O. Secondary alcohols, especially benzylic and aliphatic alcohols, were smoothly transformed into corresponding ketones with up to 92% yields at room temperature under one atmosphere pressure of oxygen. The influences of reaction conditions such as solvent, different metal catalyst, catalyst loading and the structure of alcohols on the promotion effect were studied. And a possible radical mechanism for the oxidation of secondary alcohols in Fe(NO3)3·9H 2O/NHPI/O2 system was proposed.
