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https://www.readbyqxmd.com/read/28212043/cbr4-as-a-halogen-bond-donor-catalyst-for-the-selective-activation-of-benzaldehydes-to-synthesize-%C3%AE-%C3%AE-unsaturated-ketones
#1
Imran Kazi, Somraj Guha, Govindasamy Sekar
CBr4 has been employed as a halogen bond donor catalyst for the selective activation of aldehyde, to achieve an efficient solvent- and metal-free C═C bond forming reaction in the presence of strong acid sensitive groups such as methoxy, cyanide, ester, and ketal for the synthesis of α,β-unsaturated ketones. This unique capability of CBr4 to act as a halogen bond donor has been explored and established using UV-vis as well as IR spectroscopy. Moreover, this unprecedented methodology enables the synthesis of the pharmaceutically important molecule licochalcone A...
February 17, 2017: Organic Letters
https://www.readbyqxmd.com/read/28212014/metal-free-synthesis-of-c-4-substituted-pyridine-derivatives-using-pyridine-boryl-radicals-via-a-radical-addition-coupling-mechanism-a-combined-computational-and-experimental-study
#2
Guoqiang Wang, Jia Cao, Liuzhou Gao, Wenxin Chen, Wenhao Huang, Xu Cheng, Shuhua Li
Density functional theory investigations revealed that the pyridine-boryl radical generated in situ using 4-cyanopyridine and bis(pinacolato)diboron could be used as a bifunctional "reagent", which serves as not only a pyridine precursor but also a boryl radical. With the unique reactivity of such radicals, 4-substituted pyridine derivatives could be synthesized using α, β-unsaturated ketones and 4-cyanopyridine via a novel radical addition/C-C coupling mechanism. Several controlled experiments were conducted to provide supportive evidence for the proposed mechanism...
February 17, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28211692/asymmetric-aziridination-of-n-sulphonyl-ketimines-with-unfunctionalized-ketones-a-one-pot-approach-to-multi-substituted-fused-aziridines
#3
Sheng Zhang, Lijun Li, Lilan Xin, Wenmin Liu, Kun Xu
A highly diastereo- and enantioselective aziridination of N-sulphonyl ketimines with unfunctionalized ketones was reported. In this efficient method, a sequential direct asymmetric Mannich reaction and oxidative C-H amination were involved, which enabled a straightforward route to multisubstituted fused aziridines in one pot. More importantly, two different products could be selectively obtained in the reaction by adding or removing a metal additive.
February 17, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28211231/visible-light-promoted-asymmetric-cross-dehydrogenative-coupling-of-tertiary-amines-to-ketones-by-synergistic-multiple-catalysis
#4
Qi Yang, Long Zhang, Chen Ye, Sanzhong Luo, Li-Zhu Wu, Chen-Ho Tung
Reported herein is an unprecedented photocatalytic asymmetric cross-dehydrogenative coupling reaction between tertiary amines and simple ketones, and it proceeds by synergistic multiple catalysis with substoichiometric amounts of a hydrogen acceptor. This process is enabled by a simple chiral primary amine catalyst through the coupling of a catalytic enamine intermediate and an iminium cation intermediate in situ generated from tetrahydroisoquinoline derivatives by coupled Ru/Co catalysis.
February 17, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28210740/catalyst-free-synthesis-of-%C3%AE-fluoro-%C3%AE-hydroxy-ketones-%C3%AE-fluoro-ynols-via-electrophilic-fluorination-of-tertiary-propargyl-alcohols-using-selectfluor%C3%A2-f-teda-bf4
#5
Naganaboina Naveen, Rengarajan Balamurugan
A facile method for the synthesis of α-fluoro-β-hydroxy ketones/α-fluoro-ynols from tertiary propargyl alcohols under electrophilic fluorination conditions using F-TEDA-BF4 has been presented. The products bear pharmaceutically important α-fluoro ketone, gem-diaryl and fluorohydrin moieties in the same molecule. Interestingly, this catalyst free protocol results in monofluorination.
February 17, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28210401/zygomatic-intraosseous-hemangioma-case-report-and-literature-review
#6
REVIEW
David B Powers, Elda Fisher, Detlev Erdmann
Intraosseous hemangiomas are uncommon intrabony lesions, representing approximately 0.5 to 1% of all intraosseous tumors. Their description varies from "benign vasoformative neoplasms" to true hamartomatous proliferations of endothelial cells forming a vascular network with intermixed fibrous connective tissue stroma. These commonly present as a firm, painless swelling. Intraosseous hemangiomas present more commonly in females than in males and most likely occur in the fourth decade of life. The most common etiology of intraosseous hemangioma is believed to be prior trauma to the area...
March 2017: Craniomaxillofacial Trauma & Reconstruction
https://www.readbyqxmd.com/read/28210213/corrigendum-exogenous-ketone-supplements-reduce-anxiety-related-behavior-in-sprague-dawley-and-wistar-albino-glaxo-rijswijk-rats
#7
Csilla Ari, Zsolt Kovács, Gabor Juhasz, Cem Murdun, Craig R Goldhagen, Andrew P Koutnik, Angela M Poff, Shannon L Kesl, Dominic P D'Agostino
[This corrects the article on p. 137 in vol. 9, PMID: 27999529.].
2017: Frontiers in Molecular Neuroscience
https://www.readbyqxmd.com/read/28208286/derivatization-technique-to-identify-specifically-carbonyl-groups-by-infrared-spectroscopy-characterization-of-photooxidative-aging-products-in-terpenes-and-terpeneous-resins
#8
Stefan Zumbühl, Andreas Brändle, Andreas Hochuli, Nadim C Scherrer, Walter Caseri
Analysis of bioorganic materials by infrared spectroscopy (FT-IR) is frequently limited due to overlapping of diagnostic bands from the various components, which poses a fundamental problem to this analytical technique. The distinction of oxidized di- and triterpenes, for example, is hindered by the superposition of similar absorption bands of carbonyl functional groups summing up to a broad, nondistinctive signal. This study presents a technique for selective fluorination of various carboxylic acids by exposure to gaseous sulfur tetrafluoride...
February 7, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28207859/differential-effects-of-silencing-crustacean-hyperglycemic-hormone-gene-expression-on-the-metabolic-profiles-of-the-muscle-and-hepatopancreas-in-the-crayfish-procambarus-clarkii
#9
Wenfeng Li, Kuo-Hsun Chiu, Yi-Chun Tien, Shih-Fu Tsai, Li-Jane Shih, Chien-Hsun Lee, Jean-Yves Toullec, Chi-Ying Lee
In order to functionally characterize the metabolic roles of crustacean hyperglycemic hormone (CHH), gene expression of CHH in the crayfish (Procambarus clarkii) was knocked down by in vivo injection of CHH double-stranded RNA (dsRNA), followed by metabolomic analysis of 2 CHH target tissues (the muscle and hepatopancreas) using nuclear magnetic resonance spectroscopy. Compared to the levels in untreated and saline-injected (SAI) animals, levels of CHH transcript, but not those of molt-inhibiting hormone (a CHH-family peptide), in the eyestalk ganglia of CHH dsRNA-injected (DSI) animals were significantly decreased at 24, 48, and 72 hour post injection (hpi), with concomitant changes in levels of CHH peptide in the sinus gland (a neurohemal organ) and hemolymph...
2017: PloS One
https://www.readbyqxmd.com/read/28207721/clinical-anatomy-e-cases-a-five-year-follow-up-of-learning-analytics
#10
Geoffrey Braatvedt, Amelia Tekiteki, Holly Britton, John Wallace, Manish Khanolkar
AIMS: To examine the length of stay and need for intensive care of people admitted with diabetic ketoacidosis (DKA) to a single centre between 1988 and 2011. METHODS: Patients aged ≥15 years admitted for the first time with DKA (plasma glucose ≥ 10mmol/L and a bicarbonate concentration ≤15mmol/L and a pH <7.35, and raised plasma or urine ketones or anion gap) to Auckland City Hospital from 1988-2011 were identified retrospectively. The patients were divided into four cohorts (1988-1996; 1997-2001; 2002-2006; 2007-2011)...
February 17, 2017: New Zealand Medical Journal
https://www.readbyqxmd.com/read/28206968/intratumoral-lactate-metabolism-in-barrett-s-esophagus-and-adenocarcinoma
#11
Heikki Huhta, Olli Helminen, Sami Palomäki, Joonas H Kauppila, Juha Saarnio, Petri P Lehenkari, Tuomo J Karttunen
BACKGROUND: Monocarboxylate transporters (MCTs) are cell membrane proteins which transport pyruvate, lactate and ketone bodies across the plasma membrane. MCTs are activated in various cancers, but their expression in esophageal adenocarcinoma is not known. The present study was conducted to elucidate the expression of MCTs in esophageal adenocarcinoma and its precursor lesions. RESULTS: Cytoplasmic MCT1, MCT4 and MTCO1 expression linearly increased from normal epithelium to Barrett's mucosa to dysplasia and cancer...
February 11, 2017: Oncotarget
https://www.readbyqxmd.com/read/28206766/copper-assisted-direct-nitration-of-cyclic-ketones-with-ceric-ammonium-nitrate-for-the-synthesis-of-tertiary-%C3%AE-nitro-%C3%AE-substituted-scaffolds
#12
Zhi-Qiang Zhang, Tao Chen, Fu-Min Zhang
An efficient and direct Cu-assisted nitrating approach to create synthetically valuable and challenging tertiary α-nitro-α-substituted moieties has been developed using ceric ammonium nitrate as a nitrating reagent, oxidant, and Lewis acid. Notably, the commonly used clinical drug ketamine was smoothly synthesized in four steps.
February 16, 2017: Organic Letters
https://www.readbyqxmd.com/read/28206690/template-assisted-meta-c-h-alkylation-and-alkenylation-of-arenes
#13
Sukdev Bag, Ramasamy Jayarajan, Rahul Mondal, Debabrata Maiti
To expand the scope of meta-functionalization, a pyrimidine-based template effective for the formation of β-aryl aldehydes and ketones, using allyl alcohols, by meta-C-H activation of benzylsulfonyl esters is described. In addition, α,β-unsaturated aldehydes were generated by in situ olefination and deprotection of allyl benzyl ethers. These new functionalizations at the meta-position of an arene have also been successfully implemented in benzylphosphonate, phenethyl carbonyl, and phenethylsulfonyl ester scaffolds...
February 16, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28203360/blood-versus-urine-ketone-monitoring-in-a-pediatric-cohort-of-patients-with-type-1-diabetes-a-crossover-study
#14
Line Goffinet, Thierry Barrea, Véronique Beauloye, Philippe A Lysy
BACKGROUND: The aim of our study was to determine the influence of routine ketone monitoring on hyperglycemic events (HE) and ketosis in youngsters with type 1 diabetes (T1D). METHODS: Our single-site, controlled and randomized study was conducted on children and adolescents with T1D outside of remission phase. During two crossover periods of 6 months, patients (n = 22) experiencing HE tested ketones alternatively with a blood ketone meter or urine ketone test strips and gave their opinion on screening methods after completion of clinical trial...
January 2017: Therapeutic Advances in Endocrinology and Metabolism
https://www.readbyqxmd.com/read/28199890/gc-ms-gc-ms-ms-and-gc-ir-differentiation-of-desoxy-cathinone-derivatives-cyclic-tertiary-amines-related-to-mdpv
#15
Younis Abiedalla, Jack DeRuiter, C Randall Clark
The desoxy phenethylamine analogues in this study represent a combination of alkyl side-chain and cyclic amines (azetidine, pyrrolidine, piperidine and azepane) to yield a set of molecules of identical elemental composition as well as major mass spectral fragment ions (base peaks) of identical elemental composition. These desoxy phenethylamine analogues of the aminoketone designer drug, 3,4-methylenedioxy-pyrrovalerone (MDPV) related to the natural product cathinone were prepared from piperonal (3,4-methylenedioxybenzaldehyde) via the intermediate precursor ketones...
February 7, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28199884/three-dimensional-growth-of-human-endothelial-cells-in-an-automated-cell-culture-experiment-container-during-the-spacex-crs-8-iss-space-mission-the-spheroids-project
#16
Jessica Pietsch, Samuel Gass, Stefano Nebuloni, David Echegoyen, Stefan Riwaldt, Christin Baake, Johann Bauer, Thomas J Corydon, Marcel Egli, Manfred Infanger, Daniela Grimm
Human endothelial cells (ECs) were sent to the International Space Station (ISS) to determine the impact of microgravity on the formation of three-dimensional structures. For this project, an automatic experiment unit (EU) was designed allowing cell culture in space. In order to enable a safe cell culture, cell nourishment and fixation after a pre-programmed timeframe, the materials used for construction of the EUs were tested in regard to their biocompatibility. These tests revealed a high biocompatibility for all parts of the EUs, which were in contact with the cells or the medium used...
February 7, 2017: Biomaterials
https://www.readbyqxmd.com/read/28199064/systematic-molecular-design-of-ketone-derivatives-of-aromatic-molecules-for-lithium-ion-batteries-first-principles-density-functional-theory-modelling
#17
Jong Hoo Park, Tianyuan Liu, Ki Chul Kim, Seung Woo Lee, Seung Soon Jang
The thermodynamic and electrochemical redox properties for a set of ketones derivatives of phenalenyl and anthracene are investigated to assess their potential application for positive electrode materials in rechargeable lithium-ion batteries. Using the first-principles density functional theory (DFT) method, we find that 1) the thermodynamic stabilities of ketone derivatives are strongly dependent on the distribution of the carbonyl groups and 2) the redox potential is increased with increasing the number of the incorporated carbonyl groups: the highest values are 3...
February 15, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28195381/mild-aqueous-%C3%AE-arylation-of-ketones-towards-new-diversification-tools-for-halogenated-metabolites-and-drug-molecules
#18
Enrico Marelli, Yohann Renault, Sunil V Sharma, Steven P Nolan, Rebecca Jane Miriam Goss
The palladium-catalyzed aqueous α-arylation of ketones was developed and tested for a large variety of reaction partners. These mild conditions enabled the coupling of aryl/ alkyl-ketones with N-protected halotryptophans, heterocyclic haloarenes, and challenging base-sensitive compounds. The synthetic potential of this new methodology for the diversification of complex bioactive molecules was exemplified by derivatising prochlorperazine. The methodology is mild, aqueous and flexible, representing a means of functionalizing a wide range of halo-aromatics and therefore has the potential to be extended to complex molecule diversification...
February 14, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28195283/generation-of-cycloalkynes-through-deprotonation-of-cyclic-enol-triflates-with-magnesium-bisamides
#19
Yuto Hioki, Kentaro Okano, Atsunori Mori
Deprotonative generation of cyclohexynes, cycloheptynes, and cyclooctynes was achieved by controlling the reactivities of transient anionic species from the corresponding enol triflates with magnesium bis(2,2,6,6-tetramethylpiperidide) as a base. The starting enol triflates are readily obtained through triflation of the corresponding ketones, allowing direct access to the cycloalkynes.
February 14, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28193410/determination-of-phospholipids-in-soybean-lecithin-samples-via-the-phosphorus-monoxide-molecule-by-high-resolution-continuum-source-graphite-furnace-molecular-absorption-spectrometry
#20
Laís N Pires, Geovani C Brandão, Leonardo S G Teixeira
This paper presents a method for determining phospholipids in soybean lecithin samples by phosphorus determination using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) via molecular absorption of phosphorus monoxide. Samples were diluted in methyl isobutyl ketone. The best conditions were found to be 213.561nm with a pyrolysis temperature of 1300°C, a volatilization temperature of 2300°C and Mg as a chemical modifier. To increase the analytical sensitivity, measurement of the absorbance signal was obtained by summing molecular transition lines for PO surrounding 213nm: 213...
June 15, 2017: Food Chemistry
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