keyword
MENU ▼
Read by QxMD icon Read
search

Ketones

keyword
https://www.readbyqxmd.com/read/28734165/rhodamine-spirolactam-sensors-operated-by-sulfur-cooperated-metal-complexation
#1
Gisuk Heo, Dahye Lee, Chi Gwan Kim, Jung Yun Do
New rhodamine Schiff base sensors were developed to improve selective sensing by introducing sulfide, ester, and dithiocarbonate groups, as well as using ketones coupled to rhodamine-hydrazine. Metal sensing proceeded through the 1:1 complexation of the metal ion for most sensors in the presence of Cu(2+) and Hg(2+). A sensor carrying a dithiocarbonate group responded selectively to Hg(2+) showing a strong colorimetric change and intense fluorescence. The association constants of the sensors were determined from a linear plot performed at micro-molar concentrations to afford values in the range of 10(4)...
July 15, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28731345/asymmetric-%C3%AE-sulfonyl-and-%C3%AE-phosphoryl-oxylation-of-ketones-by-a-chiral-hypervalent-iodine-iii
#2
Guillaume Levitre, Audrey Dumoulin, Pascal Retailleau, Armen Panossian, Frederic R Leroux, Géraldine Masson
An enantioselective direct oxygenation of propiophenone derivatives mediated by a catalytic or stoichiometric amount of new chiral non-C2-symmetric iodoarenes(III) is reported. The reaction gives an easy entry to optically active α-sulfonyl- and α-phosphoryl oxyketones in respectable yields and enantioselectivities.
July 21, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28730822/distributions-of-polycyclic-aromatic-hydrocarbons-aromatic-ketones-carboxylic-acids-and-trace-metals-in-arctic-aerosols-long-range-atmospheric-transport-and-photochemical-degradation-production-at-polar-sunrise
#3
Dharmendra Kumar Singh, Kimitaka Kawamura, Ayako Yanase, Leonard Barrie
The distributions, correlations and source apportionment of aromatic acids, aromatic ketones, polycyclic aromatic hydrocarbons (PAHs) and trace metals were studied in Canadian high Arctic aerosols. 19 PAHs including minor sulphur-containing heterocyclic PAH (dibenzothiophene) and major 6 carcinogenic PAHs were detected with a high proportion of fluoranthene followed by benzo[k]fluoranthene, pyrene and chrysene. However, in the sunlit period of spring, their concentrations significantly declined likely due to photochemical decomposition...
July 21, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28730716/manganese-i-catalyzed-enantioselective-hydrogenation-of-ketones-using-a-defined-chiral-pnp-pincer-ligand
#4
Marcel Garbe, Kathrin Junge, Svenja Walker, Zhihong Wei, Haijun Jiao, Anke Spannenberg, Stephan Bachmann, Michelangelo Scalone, Matthias Beller
A new chiral manganese PNP pincer complex is described. Asymmetric hydrogenation of several prochiral ketones with molecular hydrogen in the presence of this complex proceeds under mild conditions (40 °C, 4 h, 30 bar H₂). Besides high catalytic activity for aromatic substrates, aliphatic ketones are hydrogenated with remarkable selectivities (er up to 92:8). DFT calculations support an outer sphere hydrogenation mechanism as well as the experimentally determined stereochemistry.
July 21, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28730195/copper-catalyzed-stereoconvergent-cis-diastereoselective-borylative-cyclization-of-%C3%AF-mesylate-%C3%AE-%C3%AE-unsaturated-esters-and-ketones
#5
Ya-Jie Zuo, Xiao-Tong Chang, Zhi-Ming Hao, Chong-Min Zhong
The Cu(i)-catalyzed stereoconvergent borylative cyclization of ω-mesylate-α,β-unsaturated compounds is facilitated by a simple Cu-bisphosphine catalyst. This reaction provides a novel route to cis-β-boron-substituted five- and six-membered carbocycle and heterocycle esters. Mechanistic studies indicate that stereoconvergence and cis-substitution likely stem from the rapid enolation of the borylcopper adduct with the substrate double bond and the formation of a five-membered intermediate, respectively.
July 21, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28727455/electron-deficient-chiral-lactic-acid-based-hypervalent-iodine-reagents
#6
Jihan Qurban, Mohamed Elsherbini, Thomas Wirth
Novel electron-deficient chiral hypervalent iodine reagents were prepared in good overall yields. The reactivity and stereoselectivity of these reagents in oxidative rearrangements of alkenes to α-aryl ketones was investigated. The results show that the new reagents have good reactivity and generate products with high enantiomeric excess.
July 20, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28727431/pd-catalyzed-iodide-promoted-%C3%AE-arylation-of-ketones-for-the-regioselective-synthesis-of-isocoumarins
#7
Alessandra Casnati, Raimondo Maggi, Giovanni Maestri, Nicola Della Ca', Elena Motti
A variety of isocoumarins have been synthesized directly from 2-halobenzoates and ketones through a palladium-catalyzed α-arylation step followed by an intramolecular cyclization process. The addition of iodide anions to the reaction mixture increased yields and selectivities especially when 2-bromobenzoates were employed. This phosphine-free one-pot synthesis features a high functional group tolerance and gives access to richly decorated isocoumarins. This general methodology was successful in the total synthesis of Xyridin A, an important natural product with antibacterial and antifungal activity...
July 20, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28727189/inversion-of-cpadh5-enantiopreference-and-altered-chain-length-specificity-for-methyl-3-hydroxyalkanoates
#8
Yunus Ensari, Gaurao V Dhoke, Mehdi D Davari, Marco Bocola, Anna Joelle Ruff, Ulrich Schwaneberg
Expanding the substrate scope of enzymes opens up new routes for synthesis of valuable chemicals. Ketone-functionalized fatty acid derivatives and corresponding chiral alcohols are valuable building blocks for the synthesis of a variety of chemicals including pharmaceuticals. The alcohol dehydrogenase from Candida parapsilosis (cpADH5) catalyzes the reversible oxidations of chiral alcohols and has a broad substrate range; a challenge for cpADH5 is to convert alcohols with small substituents (methyl or ethyl) next to the oxidized alcohol moiety...
July 20, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28727129/potentialization-of-n-a-tosyl-l-phenylalanine-chloromethyl-ketone-tpck-cytotoxic-activity-by-2-1-adamantylamino-6-methylpyridine-adamp-in-human-ovarian-cancer-cells
#9
Jacek Sieńko, Witold Lasek, Justyna Teliga-Czajkowska, Roman Smolarczyk, Krzysztof Czajkowski
OBJECTIVES: TNF is one of the key cytokines involved in cancer development. TNF signaling can result in both stimulating and inhibitory signals that can result in opposite biological effects in cancerogenesis. 2-(1-adamantylamino)-6-methylpyridine (AdAMP) enhances TNF secretion whereas N-a-tosyl-L-phenylalanine chloromethyl ketone (TPCK) is a NF-κB inhibitor potentially stimulating proapoptotic TNF signals. The aim of the study was to assess the effect of TPCK in combination with AdAMP on human ovarian cells...
2017: Ginekologia Polska
https://www.readbyqxmd.com/read/28726345/enantioselective-construction-of-trifluoromethoxylated-stereogenic-centers-by-nickel-catalyzed-asymmetric-suzuki-miyaura-coupling-of-secondary-benzyl-bromides
#10
Weichen Huang, Xiaolong Wan, Qilong Shen
A method for the construction of trifluoromethoxy-containing stereogenic centers with high enantiometric excess via nickel-catalyzed Suzuki-Miyaura coupling of easily available -bromobenzyl trifluoromethylethers 1a-g with a variety of aryl pinacol boronates was described. The reaction conditions were mild and a variety of common functional groups such as fluoride, chloride, bromide, ester, enolizable ketone, nitro, cyano, amino and vinyl group were well tolerated. Furthermore, the reaction can be easily scaled up to gram quantities without erosion of the enantioselectivity...
July 20, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28726122/beta-ketothiolase-deficiency-presenting-with-metabolic-stroke-after-a-normal-newborn-screen-in-two-individuals
#11
Monica H Wojcik, Klaas J Wierenga, Lance H Rodan, Inderneel Sahai, Sacha Ferdinandusse, Casie A Genetti, Meghan C Towne, Roy W A Peake, Philip M James, Alan H Beggs, Catherine A Brownstein, Gerard T Berry, Pankaj B Agrawal
Beta-ketothiolase (mitochondrial acetoacetyl-CoA thiolase) deficiency is a genetic disorder characterized by impaired isoleucine catabolism and ketone body utilization that predisposes to episodic ketoacidosis. It results from biallelic pathogenic variants in the ACAT1 gene, encoding mitochondrial beta-ketothiolase. We report two cases of beta-ketothiolase deficiency presenting with acute ketoacidosis and "metabolic stroke." The first patient presented at 28 months of age with metabolic acidosis and pallidal stroke in the setting of a febrile gastrointestinal illness...
July 20, 2017: JIMD Reports
https://www.readbyqxmd.com/read/28724414/effects-of-feeding-drunken-horse-grass-infected-with-epichlo%C3%A3-gansuensis-endophyte-on-animal-performance-clinical-symptoms-and-physiological-parameters-in-sheep
#12
Ying Liang, Hucheng Wang, Chunjie Li, Zhibiao Nan, Fadi Li
BACKGROUND: Many reports showed that grass-endophyte symbiosis induced livestock poisoned. Yet, there is no study evaluating clinical symptoms and physiological parameters in sheep fed Epichloë gansuensis endophyte-infected grass. The objective of the present study was to investigate these indexes by feeding sheep with endophyte-infected A. inebrians (E+ Group) or endophyte-free A. inebrians (E- Group) drunken horse grass or alfalfa hay (Control Group). RESULTS: The Epichloë endophyte caused obvious toxicity symptoms in the sheep fed E+ A...
July 19, 2017: BMC Veterinary Research
https://www.readbyqxmd.com/read/28723160/phosphine-catalyzed-enantioselective-4-2-annulation-of-o-quinone-methides-with-allene-ketones
#13
Zhen Wang, Tianli Wang, Weijun Yao, Yixin Lu
A phosphine-catalyzed highly enantioselective [4 + 2] annulation between ortho-quinone methides and allene ketones has been developed. The reported method led to the formation of chromane derivatives in high yields and excellent enantioselectivity. This is the first time that ortho-quinone methides are employed in phosphine-mediated cyclization reactions.
July 19, 2017: Organic Letters
https://www.readbyqxmd.com/read/28722412/rh-catalyzed-regioselective-ortho-c-h-carbenoid-insertion-of-diarylazines
#14
Yunliang Yu, Changsheng Kuai, Remi Chauvin, Nian Tian, Shuangshuang Ma, Xiuling Cui
Rh-catalyzed ortho-C-H carbenoid insertion reaction of diarylazines with diazo compounds has been developed. A wide range of ortho-substituted diarylazines have been obtained in moderate to high yields with high regioselectivity at room temperature. Hydrolysis of the products could release ketones or aldehydes, giving access to aromatic 1,5-keto-diesters as valuable synthons for further chemical transformations.
July 19, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28722411/pathways-in-the-degradation-of-geminal-diazides
#15
Kristina Holzschneider, Andreas P Häring, Alexander Haack, Daniel J Corey, Thorsten Benter, Stefan F Kirsch
The degradation of geminal diazides is described. We show that diazido acetates are converted into tetrazoles through the treatment with bases. The reaction of dichloro ketones with azide anions provides acyl azides, through in situ formation of diazido ketones. We present experimental and theoretical evidence that both fragmentations may involve the generation of acyl cyanide intermediates. The controlled degradation of terminal alkynes into amides (by loss of one carbon) or ureas (by loss of two carbons) is also shown...
July 19, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28722252/efficient-access-to-all-carbon-quaternary-and-tertiary-%C3%AE-functionalized-homoallyl-aldehydes-from-ketones
#16
Vittorio Pace, Laura Castoldi, Eugenia Mazzeo, Marta Rui, Thierry Langer, Wolfgang Holzer
Widely substituted all-carbon quaternary and tertiary α-homoallyl aldehydes are rapidly assembled through a unique synthetic operation from ketones consisting in: 1) C1-homologation; 2) epoxide-aldehyde Lewis acid mediated isomerization and, 3) electrophilic trapping. The synthetic equivalence between a vinyl oxirane and a β,γ-unsaturated aldehyde is the key concept for introducing such a previously undisclosed tactic. Mechanistic studies and labeled experiments suggest the intervention of an aldehyde enolate as the crucial intermediate...
July 19, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28719218/palladium-copper-catalyzed-oxidative-coupling-of-arylboronic-acids-with-isocyanides-selective-routes-to-amides-and-diaryl-ketones
#17
Fangling Lu, Ziyue Chen, Zhen Li, Xiaoyan Wang, Xinyue Peng, Cong Li, Lingtong Fang, Dong Liu, Meng Gao, Aiwen Lei
An efficient and alternative oxidative cross-coupling strategy starting from arylboronic acids and isocyanides for the selective synthesis of amides and diaryl ketones with palladium/copper catalysis is developed. Various substituted benzamides and benzophenones could be obtained in good yields. The reaction represents an efficient and alternative strategy for the synthesis of carbonyl compounds.
July 18, 2017: Organic Letters
https://www.readbyqxmd.com/read/28718645/fourfold-interpenetrated-mof-ni-pybz-2-as-coating-material-in-gas-chromatographic-capillary-column-for-separation
#18
Yan Zhang, Li Wang, Ru-Xin Yao, Xian-Ming Zhang
A fourfold interpenetrated diamond-like topological metal-organic framework (MOF), Ni(pybz)2 [pybz = 4-(4-pyridyl)benzoate] was successfully synthesized and fully characterized. This MOF can serve as coating material in gas chromatographic capillary column for the separation of some low boiling point essential oils. The prepared columns have good recognition ability and excellent selectivity toward a series of organic compounds, including alcohols, aldehydes, ketones, carboxylic acid, ethers, ester, and amines...
July 18, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28717894/determination-of-ketones-and-ethyl-acetate-a-preliminary-study-for-the-discrimination-of-patients-with-lung-cancer
#19
Patricia Martín Santos, Miguel Del Nogal Sánchez, Ángel Pedro Crisolino Pozas, José Luis Pérez Pavón, Bernardo Moreno Cordero
In this work, ten possible volatile biomarkers of lung cancer (acetone, 2-butanone, ethyl acetate, 2-pentanone, 4-methyl-2-pentanone, 2-hexanone, 3-heptanone, 2-heptanone, 3-octanone, and 2-nonanone) have been analyzed to evaluate their different concentration levels in urine samples from lung cancer patients (n = 12) and healthy controls (n = 12). The volatile compounds were generated with a headspace autosampler and analyzed with a gas chromatograph equipped with a programmed temperature vaporizer and mass spectrometry detector (HS-PTV-GC-MS)...
July 17, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28717256/ketone-catalyzed-photochemical-c-sp-3-h-chlorination
#20
Lei Han, Jibao Xia, Lin You, Chuo Chen
Photoexcited arylketones catalyze the direct chlorination of C(sp(3))-H groups by N-chlorosuccinimide. Acetophenone is the most effective catalyst for functionalization of unactivated C-H groups while benzophenone provides better yields for benzylic C-H functionalization. Activation of both acetophenone and benzophenone can be achieved by irradiation with a household compact fluorescent lamp. This light-dependent reaction provides a better control of the reaction as compared to the traditional chlorination methods that proceed through a free radical chain propagation mechanism...
June 29, 2017: Tetrahedron
keyword
keyword
15159
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"