Search Within
83253
Applied Filters:
Keyword:'83253'
Showing 1-27 of 27 results for "83253" within Papers
Capillary electrophoresis determinative and GC-MS confirmatory method for water-soluble organic acids in airborne particulate matter and vehicle emission.
Dabek-Zlotorzynska E, et al.
Journal of Separation Science, 28(13), 1520-1528 (2005)
Casey R Wade et al.
Chemical communications (Cambridge, England), 46(34), 6380-6381 (2010-08-07)
The presence of a proximal cationic group in zwitterionic aryltrifluoroborates such as o-(Ph(2)MeP)C(6)H(4)(BF(3)) stabilizes these compounds against hydrolysis.
Ramanathan Rajaganesh et al.
Carbohydrate research, 345(12), 1649-1657 (2010-06-29)
BF(3).Et(2)O-catalysed O-glycosylation of 1,2,3-tri-O-acetyl-4,6-O-butylidene- and ethylidene-beta-d-glucopyranose with different aliphatic and aromatic alcohols proceeds for the most part with complete retention of anomeric configuration. Antioxidant activity of O-glycosides shows significant inhibition (IC(50) approximately 77%). 1,3-Dipolar cycloaddition of terminal alkyne derivatives of
Bandna et al.
Natural product research, 23(15), 1445-1450 (2009-10-08)
Acylation of beta-caryophyllene, a sesquiterpene hydrocarbon with acetic anhydride, was carried out under mild catalytic conditions using Lewis acids such as BF3.Et2O, ZnCl2, FeCl3, I2 and AlCl3 as catalysts. Among these, BF3.Et2O was found to catalyse the reaction most efficiently
Joanna E Rode et al.
Chirality, 24(1), 5-16 (2011-12-06)
Stabilization energies of the electron donor-acceptor sulfinimine···BF(3) complexes calculated at either the B3LYP/aug-cc-pVTZ or the MP2/aug-cc-pVTZ level do not allow to judge, whether the N- or O-atom in sulfinimine is stronger electron-donor to BF(3) . The problem seems to be
Joseph J Topczewski et al.
The Journal of organic chemistry, 74(18), 6965-6972 (2009-08-25)
The first total synthesis of (+)-schweinfurthin B, a potent and differentially active cytotoxic agent, has been accomplished. Completion of the synthesis required just 16 steps in the longest linear sequence from commercially available vanillin. Key synthetic transformations included a Shi
T Mizuno et al.
The Journal of chemical physics, 136(7), 074305-074305 (2012-03-01)
Recoil frame photoelectron angular distributions (RFPADs) of BF(3) molecules are presented over the energy region of the shape resonance in the F 1s continuum. Time-dependent density functional theory calculations are also given to understand the shape resonance dynamics. The RFPADs
Wenhe Zhong et al.
The Journal of organic chemistry, 76(24), 9997-10004 (2011-11-19)
Selective syn and anti diacetoxylations of alkenes have been achieved using a PhI(OAc)(2)/BF(3)·OEt(2) system in the presence and absence of water, respectively. A broad range of substrates including electron-deficient alkenes (such as α,β-unsaturated esters) could be elaborated efficiently at room
The influence of the acidity of ionic liquids on catalysis.
Xinjiang Cui et al.
ChemSusChem, 3(9), 1043-1047 (2010-08-18)
Linan Yang et al.
Journal of the American Society for Mass Spectrometry, 24(4), 563-572 (2013-03-21)
A negatively charged biradical intermediate was successfully generated in the gas phase via cyclization of the deprotonated bicyclo[8.3.0]trideca-12-ene-2,7-diyn-1-one precursor. The inherent negative charge of this biradical allows its characterization via collision-activated dissociation and reactions with a variety of neutral substrates
Karsten Müller et al.
Journal of chromatography. A, 1260, 9-15 (2012-09-11)
A method for the ultra trace analysis of 21 fluorobenzoic acids (FBAs) via GC-MS based on solid-phase extraction (SPE) and derivatization with BF3·MeOH is described. All fluorobenzoic acids were enriched and determined simultaneously. Solid-phase extraction on hydrophilic-lipophilic-balanced reversed-phase cartridges containing
Ahmad Makahleh et al.
Talanta, 81(1-2), 20-24 (2010-03-02)
A reversed-phase high-performance liquid chromatographic method with capacitively coupled contactless conductivity detector (C(4)D) has been developed for the separation and the simultaneous determination of five underivatized long chain fatty acids (FAs), namely myristic, palmitic, stearic, oleic, and linoleic acids. An
Brieuc Guillerm et al.
Macromolecular rapid communications, 33(19), 1600-1612 (2012-07-05)
Polyoxazolines (POx) are increasingly being studied as polymeric building blocks due to the possibility of affording tunable properties. Additionally, as the biocompatibility and stealth behavior of POx are similar to that of poly(ethylene glycol) (PEG), it has become challenging to
G K Surya Prakash et al.
Organic letters, 13(15), 4128-4131 (2011-07-14)
The one-pot synthesis of 1,1,1-trifluoro- and 1,1-difluoro-2,2-diarylethanes from arenes and fluorinated hemiacetals in the BF(3)-H(2)O system is described. The reaction is simple, clean, and convenient, eliminating the use of organic solvents and other expensive acid systems. BF(3)-H(2)O is economic, is
Gewu Lu et al.
ACS nano, 2(11), 2342-2348 (2009-02-12)
Polythiophene (Pth) films with aligned nanotubule arrays were adhered strongly on various smooth surfaces such as glass, mica, and GaAs after drying from their wet states under ambient condition. The normal and shear dry adhesion forces of the films on
David Chivall et al.
Rapid communications in mass spectrometry : RCM, 26(10), 1232-1240 (2012-04-14)
Compound-specific stable hydrogen isotope analysis of fatty acids is being used increasingly as a means of deriving information from a diverse range of materials of archaeological, geological and environmental interest. Preparative steps required prior to isotope ratio mass spectrometry (IRMS)
Diego dos Santos Pisoni et al.
European journal of medicinal chemistry, 45(2), 526-535 (2009-12-04)
This work describes the enantioselective synthesis of a new series of terpenic chiral 9-aminotetrahydroacridine analogues. Several chiral ketones were synthesized from natural monoterpenes in an optically active form and subjected to the cyclodehydration reactions with anthranilonitrile in the presence of
Nolan R Mente et al.
The Journal of organic chemistry, 73(20), 7963-7970 (2008-09-18)
The total synthesis of the natural stilbene (+)-schweinfurthin G (8) has been accomplished through a sequence based on an efficient cationic cascade cyclization. This cascade process is initiated by Lewis acid promoted ring opening of an epoxide and terminated through
Panayiotis V Ioannou et al.
Chemistry and physics of lipids, 163(1), 51-55 (2009-11-11)
The crucial step in the preparation of the title arsonolipids starting from the dichloromethane-soluble dithioarsonite CH(2)(OH)CH(OH)CH(2)-As(SPh)(2) is to avoid an internal cyclization during the acylation which protects the primary -OH group from being acylated. This was to a large extent
Michael P Maier et al.
Analytical and bioanalytical chemistry, 405(9), 2825-2831 (2013-02-05)
Assessing the environmental fate of chiral micropollutants such as herbicides is challenging. The complexity of aquatic systems often makes it difficult to obtain hydraulic mass balances, which is a prerequisite when assessing degradation based on concentration data. Elegant alternatives are
G K Surya Prakash et al.
The Journal of organic chemistry, 74(22), 8659-8668 (2009-10-30)
BF(3)-monohydrate is found to be an efficient and strong acid catalyst as well as an effective protosolvating medium suitable for the hydroxyalkylation of arenes with aromatic aldehydes. This reaction has been extended to aromatic dialdehydes, such as terephthalic dicarboxaldehyde and
Adriano S Vieira et al.
Organic letters, 10(22), 5215-5218 (2008-10-24)
A convenient, mild and highly stereoselective method for C-glycosidation (alkynylation) of D-glucal with various potassium alkynyltrifluoroborates, mediated by BF3x OEt2 and involving oxonium intermediates, preferentially provides the alpha-acetylene glycoside products with good yields.
Masahiko Maekawa et al.
Dalton transactions (Cambridge, England : 2003), (3)(3), 415-417 (2009-01-06)
Three novel Cu(I)-C2H4 adducts bearing 4-(2-pyridyl)pyrimidine were self-assembled, and the roles of anion and solvent were proved in the formation process.
Dongling Wu et al.
The journal of physical chemistry. A, 114(43), 11738-11745 (2010-10-07)
The reactivity of 2,6-lutidine/BR₃ and pyridine/BR₃ Lewis pairs (R = F, Me, C₆F₅) is investigated in detail by quantum chemical calculations. The observed reactivity difference of these pairs is interpreted in terms of the existence of a "frustrated complex" on
Karol Jackowski et al.
Magnetic resonance in chemistry : MRC, 47(10), 857-861 (2009-07-29)
The (1)J((11)B(19)F) spin-spin coupling of gaseous BF(3) was observed in (11)B NMR spectra as a function of density in a wide range of temperatures. Following the extrapolation of the measured values to the zero-density limit, the coupling constant free from
Sanath Kumar et al.
Journal of radiation research, 51(5), 621-626 (2010-10-06)
Boron Neutron Capture Therapy (BNCT) effectiveness depends on the preferential sequestration of boron in cancer cells relative to normal tissue cells. We present a novel strategy for sequestering boron using an adenovirus expressing the sodium iodide symporter (NIS). Human glioma
Dong Ho Park et al.
Bioorganic & medicinal chemistry letters, 22(20), 6362-6367 (2012-09-22)
The biological importance of antioxidants influenced to synthesize some curcumin-related compounds as potential antioxidants. Accordingly, a series of 2,4-diaryl-3-azabicyco[3.3.1]nonan-9-ones were synthesized with polyphenolic and/or polymethoxyphenyl groups by modified Mannich condensations. The yield was significantly improved using BF(3)·SiO(2) as heterogeneous catalyst
Page 1 of 1