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131.
A highly oxygenated, novel pentacyclic bis-oxa-bridged compound 8 was synthesized with remarkable efficiency starting from readily available tetrachloro-5,5-dimethoxyclopentadiene and 1,4-cyclohexadiene in three steps. The ruthenium-catalyzed oxidation of 2:1 bis-adduct 1 followed by a one-pot transformation of the resulting bis-alpha-diketone 3 furnished (after esterification) the title compound in an overall yield of 29.1%. The versatility of this simple method was further demonstrated with other norbornyl alpha-diketones to obtain the corresponding strained oxa-bridged derivatives. 相似文献
132.
The synthesis
of conducting polymers based on m-nitroaniline, m-chloroaniline and m-aminophenol
by aniline initiated ammonium peroxydisulfate oxidation, has been attempted.
The IR spectra of the polymers have been studied. Thermogravimetric analysis
of the conducting polymers has been followed using a computer analysis method
LOTUS PACKAGE, developed by us for assigning the degradation mechanism. A
number of equations have been used to evaluate the kinetic parameters. The
mechanism of degradation of the conducting polymers has been explained on
the basis of their kinetic parameters. 相似文献
133.
Pion mass and its decay constant have been studied in a chiral symmetric potential model of independent quarks. The non-perturbative
multi-gluon interaction which is responsible for quark confinement in a hadron is phenomenologically represented here by an
effective potentialU(r) = 1/2(1 +γ
0)(ar
2 +V
0). The residual interactions due to quark-pion coupling arising out of the chiral symmetry preservation and that due to quark-gluon
coupling arising out of single-gluon exchange are treated as low order perturbations. The centre of mass correction is also
taken into account appropriately. This leads to the
mass in consistency with that of the PCAC-pion and the pion decay constant in reasonable agreement with experiment. 相似文献
134.
Faiz Ahmed Khan Jyotirmayee Dash Rashmirekha Satapathy Sarasij K. Upadhyay 《Tetrahedron letters》2004,45(15):3055-3058
Knoevenagel condensation proceeds efficiently in recyclable [bmim]PF6 and [bmim]BF4 without any catalyst, and hydrotalcites in ionic liquid serve as a safe and recyclable reaction system for both Knoevenagel as well as nitroaldol condensations. 相似文献
135.
Summary The ligand, 4-methylimidazole L, reacts with Copper(II) to yield hexacoordinated and tetragonal complexes, CuL4X2 (X = Cl, Br, NO3, ClO4, NCS or 0.5 SO4) and CuL6(BF4)2; and tetracoordinated square-planar complexes, CuL2(N3)2, (CuL4)H9Cl4) and (Me4N)(CuLCl3). The complexes obtained were characterized on the basis of analytical data, i.r. and electronic spectra, conductance and magnetic susceptibility measurements. T.g.a, d.t.g and d.t.a studies have been made for some of the complexes which were found to decompose with loss of imidazole ligand. The stoichiometry of the thermal decompositions was determined. 相似文献
136.
Sanjay Kumar Saxena Archana Mukherjee Yogendra Kumar Ramu Ram A. S. Tapase Vivek J. Anand Ashutosh Dash 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(3):1237-1243
‘Permanent seed implantation’ using 125I- seeds has emerged as an effective treatment modality for management of prostate cancer. An indigenous technology for the production of 125I brachytherapy sources (‘BARC 125I Ocu-Prosta seed’) has been developed. In this current work, we describe an overview of our experience on large scale production of 125I brachytherapy sources, their quality assessment, in vivo bio-evaluation and initial experience on their journey from bench to bed-side for the treatment of prostate cancer. 相似文献
137.
Oxidation kinetics of benzaldehyde and some of its ortho- and para-monosubstituted derivatives have been studied using cetylpicolinium dichromates, a class of novel phase transfer oxidants, in dichloromethane medium. The rate of reaction is first order with respect to oxidant and fractional order with respect to the substrates. The Michaelis–Menten type oxidation was observed with respect to the substrates. Benzaldehydes are found to be oxidized to their corresponding acids. The mechanism of oxidation reaction has been suggested based on the solvent isotope effect, Hammett plot, and thermodynamic study. The solvent isotope effect (kCHCl3/kCDCl3 = 1.57) indicates the involvement of hydrogen exchange with the medium during oxidation reactions. A strong influence of specific solute–solvent interactions on the rate of the reaction is observed. Both the electron-withdrawing and electron-releasing substituents on the substrates accelerate the rate of reaction. 相似文献
138.
Seema Yadav Ajeet Singh Isha Mishra Sriparna Ray Shaikh M. Mobin Chandrakanta Dash 《应用有机金属化学》2019,33(7)
Well‐defined and air‐stable PEPPSI (Pyridine Enhanced Precatalyst Preparation Stabilization and Initiation) themed palladium bis‐N‐heterocyclic carbene complexes have been developed for the domino Sonogashira coupling/cyclization reaction of 2‐iodophenol with a variety of terminal alkynes and C‐H bond arylation of benzothiazole with aryl iodides. The PEPPSI themed palladium complexes, 2a and 2b were synthesized in good yields from the reaction of corresponding imidazolium salts with PdCl2 and K2CO3 in pyridine. The new air‐stable palladium‐NHC complexes were characterized by NMR spectroscopy, X‐ray crystallography, elemental analysis, and mass spectroscopy studies. The PEPPSI themed palladium(II) bis‐N‐heterocyclic carbene complexes 2a and 2b exhibited excellent catalytic activities for domino Sonogashira coupling/cyclization reaction of 2‐iodophenol with terminal alkynes yielding benzofuran derivatives. In addition, the palladium complexes, 2a and 2b successfully catalyzed the direct C‐H bond arylation of benzothiazole with aryl iodides as coupling partners in presence of CuI as co‐catalyst. 相似文献
139.
Devi Jai Pachwania Sushila Kumar Deepak Jindal Deepak Kumar Jan Suraya Dash Ashutosh K. 《Research on Chemical Intermediates》2022,48(1):267-289
Research on Chemical Intermediates - Organotin(IV) complexes are gaining major attention as drug candidates, accordingly we have synthesized a cluster of novel diorganotin(IV) complexes R2SnClL... 相似文献
140.
Journal of Solid State Electrochemistry - In the present paper, we have reported the standard molar Gibbs energy of formation for Li2CaThF8(s) measured by solid electrolyte galvanic cell technique... 相似文献