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ketones aerobic

Chieh-Kai Chan, Yu-Lin Tsai, Yi-Ling Chan, Meng-Yang Chang
A new, four-step synthetic route for substituted 2,3-benzodiazepines 1, starting from aldehyde 4, was developed with excellent overall yields. This route was carried out by the 1,2-addition of 4 with various aromatic Grignard reagents, PCC-oxidation, and aerobic Wacker-type oxidation of the olefinic group of 6, followed by condensation of the resulting 1,5-dicarbonyl 7 with N2H4. Isoquinolones 9 were obtained when an aldehyde group was used instead of a ketone. The key structures were confirmed by X-ray single crystal diffraction analysis...
October 7, 2016: Journal of Organic Chemistry
Qing-Bao Zhang, Yong-Liang Ban, Da-Gang Zhou, Pan-Pan Zhou, Li-Zhu Wu, Qiang Liu
We developed a visible-light driven oxo-acyloxylation of aryl alkenes with carboxylic acids and molecular oxygen. A metal-free photoredox system, consisting of an acridinium photocatalyst, an organic base, and molecular sieve (MS) 4 Å, promotes chemoselective aerobic photooxidation of aryl alkenes. This approach may provide a green, practical, and metal-free protocol for a wide range of α-acyloxy ketones.
September 29, 2016: Organic Letters
Jian Luo, Jian Zhang
A metal-free protocol to generate phthalimide-N-oxyl (PINO) radicals from N-hydroxyphthalimide (NHPI) via a photoinduced proton-coupled electron transfer process is reported. Using donor-substituted aromatic ketones, such as 4,4'-bis(diphenylamino)benzophenone (DPA-BP), PINO radicals are efficiently produced and subsequently utilized to functionalize olefins to afford a new class of alkyl hydroperoxides. The DPA-BP/NHPI/O2 photocatalytic system exhibits high efficiency toward the aerobic oxidation of β-O-4 lignin models...
October 7, 2016: Journal of Organic Chemistry
Q H Zhang, P K Jin, H H Ngo, X Shi, W S Guo, S J Yang, X C Wang, X Wang, M Dzakpasu, W N Yang, L Yang
This study examined the distribution of carbon sources in two anaerobic anoxic oxic (AAO) sewage treatment plants in Xi'an and investigated the transformation characteristics and utilization potential of slowly biodegradable organic matters (SBOM). Results indicated under anaerobic and aerobic conditions, SBOM could be transformed at a rate of 65% in 8h into more readily biologically utilizable substrates such as volatile fatty acids (VFAs), polysaccharides and proteins. Additionally, non-biodegradable humus-type substances which are difficult to biodegrade and readily accumulate, were also generated...
October 2016: Bioresource Technology
Gianluca Catucci, Ivan Zgrablic, Francesco Lanciani, Francesca Valetti, Daniela Minerdi, David P Ballou, Gianfranco Gilardi, Sheila J Sadeghi
BACKGROUND: Ar-BVMO is a recently discovered Baeyer-Villiger monooxygenase from the genome of Acinetobacter radioresistens S13 closely related to medically relevant ethionamide monooxygenase EtaA (prodrug activator) and capable of inactivating the imipenem antibiotic. METHODS: The co-substrate preference as well as steady-state and rapid kinetics studies of the recombinant purified protein were carried out using stopped-flow spectroscopy under anaerobic and aerobic conditions...
September 2016: Biochimica et Biophysica Acta
Lijun Gu, Cheng Jin, Hongtao Zhang, Jiyan Liu, Ganpeng Li, Zhi Yang
A Cu-mediated cyanation of aryl methyl ketones using cyanide anions as the nitrogen source was achieved to provide aromatic nitriles in moderate to good yields. The reaction tolerates a variety of synthetically important functional groups.
July 12, 2016: Organic & Biomolecular Chemistry
Paloma Navarro, Maria J Bueno, Ivana Zagorac, Tamara Mondejar, Jesus Sanchez, Silvana Mourón, Javier Muñoz, Gonzalo Gómez-López, Veronica Jimenez-Renard, Francisca Mulero, Navdeep S Chandel, Miguel Quintela-Fandino
Epithelial malignancies are effectively treated by antiangiogenics; however, acquired resistance is a major problem in cancer therapeutics. Epithelial tumors commonly have mutations in the MAPK/Pi3K-AKT pathways, which leads to high-rate aerobic glycolysis. Here, we show how multikinase inhibitor antiangiogenics (TKIs) induce hypoxia correction in spontaneous breast and lung tumor models. When this happens, the tumors downregulate glycolysis and switch to long-term reliance on mitochondrial respiration. A transcriptomic, metabolomic, and phosphoproteomic study revealed that this metabolic switch is mediated by downregulation of HIF1α and AKT and upregulation of AMPK, allowing uptake and degradation of fatty acids and ketone bodies...
June 21, 2016: Cell Reports
Theresa Sperger, Italo A Sanhueza, Franziska Schoenebeck
Computational chemistry has become an established tool for the study of the origins of chemical phenomena and examination of molecular properties. Because of major advances in theory, hardware and software, calculations of molecular processes can nowadays be done with reasonable accuracy on a time-scale that is competitive or even faster than experiments. This overview will highlight broad applications of computational chemistry in the study of organic and organometallic reactivities, including catalytic (NHC-, Cu-, Pd-, Ni-catalyzed) and noncatalytic examples of relevance to organic synthesis...
June 21, 2016: Accounts of Chemical Research
Weiping Deng, Jiashu Chen, Jincan Kang, Qinghong Zhang, Ye Wang
Functionalised carbon nanotube (CNT)-supported Au-Pd alloy nanoparticles were highly efficient catalysts for the aerobic oxidation of amines. We achieved the highest turnover frequencies (>1000 h(-1)) for the oxidative homocoupling of benzylamine and the oxidative dehydrogenation of dibenzylamine. We discovered a cooperative effect between Au-Pd nanoparticles and ketone/quinone groups on CNTs.
May 21, 2016: Chemical Communications: Chem Comm
Manikandan Selvaraju, Tzuen-Yang Ye, Chia-Hsin Li, Pei-Heng Ho, Chung-Ming Sun
A highly efficient synthesis of benzoimidazo[1,2-a]imidazolone through a novel oxidative 5-exo-dig cyclization-ketonization cascade of 2-aminobenzimidazole, aldehyde and terminal alkyne has been explored under aerobic conditions. The reaction proceeds through copper-catalyzed addition of terminal alkynes to imines derived from 2-aminobenzimidazole with aldehyde followed by intramolecular cyclization. The atmospheric molecular oxygen acts as an oxygen source for the newly formed carbonyl group in the final product...
May 5, 2016: Chemical Communications: Chem Comm
Amarajothi Dhakshinamoorthy, Abdullah M Asiri, Hermenegildo Garcia
This Concept is aimed at describing the current state of the art in metal-organic frameworks (MOFs) as heterogeneous catalysts for liquid-phase oxidations, focusing on three important substrates, namely, alkenes, alkanes and alcohols. Emphases are on the nature of active sites that have been incorporated within MOFs and on future targets to be set in this area. Thus, selective alkene epoxidation with peroxides or oxygen catalyzed by constitutional metal nodes of MOFs as active sites are still to be developed...
June 6, 2016: Chemistry: a European Journal
Johann Heider, Karola Schühle, Jasmin Frey, Bernhard Schink
Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate...
2016: Journal of Molecular Microbiology and Biotechnology
Danna Lee, Natoiya D R Lloyd, Isak S Pretorius, Anthony R Borneman
BACKGROUND: Raspberry ketone is the primary aroma compound found in raspberries and naturally derived raspberry ketone is a valuable flavoring agent. The economic incentives for the production of raspberry ketone, combined with the very poor yields from plant tissue, therefore make this compound an excellent target for heterologous production in synthetically engineered microbial strains. METHODS: A de novo pathway for the production of raspberry ketone was assembled using four heterologous genes, encoding phenylalanine/tyrosine ammonia lyase, cinnamate-4-hydroxlase, coumarate-CoA ligase and benzalacetone synthase, in an industrial strain of Saccharomyces cerevisiae...
2016: Microbial Cell Factories
Lianyue Wang, SenSen Shang, Guosong Li, Lanhui Ren, Ying Lv, Shuang Gao
We report a new Fe(NO3)3·9H2O/9-azabicyclo[3.3.1]nonan-N-oxyl catalyst system that enables efficient aerobic oxidation of a broad range of primary and secondary alcohols to the corresponding aldehydes and ketones at room temperature with ambient air as the oxidant. The catalyst system exhibits excellent activity and selectivity for primary aliphatic alcohol oxidation. This procedure can also be scaled up. Kinetic analysis demonstrates that C-H bond cleavage is the rate-determining step and that cationic species are involved in the reaction...
March 4, 2016: Journal of Organic Chemistry
Rajib Sarkar, Chhanda Mukhopadhyay
A new general method for the synthesis of acridine-1,8-diones through CDC coupling of enamino-ketones followed by rearrangement has been developed. This is a Cu(i) catalyzed procedure, based on the cross dehydrogenative coupling of the Csp(3)-H bond with the Csp(2)-H bond of enamino-ketones followed by rearrangement to acridine-1,8-diones in the presence of PTSA under an aerobic atmosphere. The synthetic route has been broadly applicable to a wide range of enamino-ketone derivatives derived from different benzyl amines as well as primary aliphatic amines having Cα(sp(3))-H bonds with various cyclic, acyclic 1,3-diketones and also using DEAD...
March 7, 2016: Organic & Biomolecular Chemistry
Lars W Andersen, Katherine M Berg, Sophia Montissol, Christopher Sulmonte, Julia Balkema, Michael N Cocchi, Richard E Wolfe, Ashok Balasubramanyam, Xiaowen Liu, Michael W Donnino
OBJECTIVES: The pyruvate dehydrogenase complex (PDH) is an essential enzyme in aerobic metabolism. Ketones are known to inhibit PDH activity, but the extent of this inhibition is unknown in patients with diabetic ketoacidosis (DKA). METHODS: We enrolled adult patients presenting to the emergency department in hyperglycemic crisis. Patients were classified as DKA or hyperglycemia without ketoacidosis based on laboratory criteria. Healthy controls were also enrolled...
June 2016: Academic Emergency Medicine: Official Journal of the Society for Academic Emergency Medicine
Ran Ma, Liang-Nian He, An-Hua Liu, Qing-Wen Song
A novel Cu(II)-catalyzed aerobic oxidative esterification of simple ketones for the synthesis of esters has been developed with wide functional group tolerance. This process is assumed to go through a tandem sequence consisting of α-oxygenation/esterification/nucleophilic addition/C-C bond cleavage and carbon dioxide is released as the only byproduct.
February 4, 2016: Chemical Communications: Chem Comm
K Ranjitha, D V Sudhakar Rao, K S Shivashankara, Tapas Kumar Roy
Present study was aimed at understanding the effect of pretreatments and modified atmosphere packaging on the quality of fresh-cut green bell pepper (Capsicum annuum L.) during low temperature storage. Dip treatment of freshly cut green bell pepper pieces in 2 % calcium propionate followed by surface drying and subsequent packing in cryovac PD961 film which maintained an equilibrium modified atmosphere of 13-14 % O2 and 7 % CO2 helped to extend the marketability till 9 days storage at 8 °C. The microbiological quality was at the best level up to 6 days of storage, as evidenced by a surge in aerobic plate count, pectinolysers and pseudomonads on subsequent days...
December 2015: Journal of Food Science and Technology
Kun Wu, Zhiliang Huang, Xiaotian Qi, Yingzi Li, Guanghui Zhang, Chao Liu, Hong Yi, Lingkui Meng, Emilio E Bunel, Jeffrey T Miller, Chih-Wen Pao, Jyh-Fu Lee, Yu Lan, Aiwen Lei
Copper-catalyzed aerobic oxidative C-H/N-H coupling between simple ketones and diamines was developed toward the synthesis of a variety of pyrazines. Various substituted ketones were compatible for this transformation. Preliminary mechanistic investigations indicated that radical species were involved. X-ray absorption fine structure experiments elucidated that the Cu(II) species 5 coordinated by two N atoms at a distance of 2.04 Å and two O atoms at a shorter distance of 1.98 Å was a reactive one for this aerobic oxidative coupling reaction...
October 2015: Science Advances
Bernd Mühldorf, Robert Wolf
A mixture of the photocatalyst riboflavin tetraacetate (RFT) and the biomimetic non-heme iron complex [Fe(TPA)(MeCN)2](ClO4)2 (TPA = tris(2-pyridylmethyl)amine) efficiently catalyzes the visible-light-driven aerobic oxidation of alkyl benzenes to ketones and carboxylic acids. An RFT-catalyzed photocycle and the independent action of the iron complex as a catalyst for H2O2 disproportionation and alkyl benzene oxygenation ensure high yields and selectivities.
January 4, 2016: Angewandte Chemie
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