611-63-2Relevant articles and documents
Fabrication of CuCr2O4 spinel nanoparticles: A potential catalyst for the selective oxidation of cycloalkanes via activation of Csp3-H bond
Acharyya, Shankha S.,Ghosh, Shilpi,Adak, Shubhadeep,Tripathi, Deependra,Bal, Rajaram
, p. 145 - 150 (2015/01/09)
We report here preparation of CuCr2O4 spinel nanoparticle catalyst, mediated by cationic surfactant CTAB in hydrothermal route. XRD revealed the formation of CuCr2O4 spinel phase and TEM showed the particle size of 30-60 nm. The catalyst was speculated to be highly active for selective oxidation of cyclohexane to cyclohexanone with H2O2. A cyclohexane conversion of 70% with 85% cyclohexanone selectivity was achieved over this catalyst at 50 °C temperature. Moreover, the catalyst did not show any significant activity loss even after 8 reuses and proved its efficacy in the oxidation of other cycloalkanes also.
Copper-catalyzed benzylic oxidation of C(sp3)-H bonds
Zhang, Bo,Zhu, Shou-Fei,Zhou, Qi-Lin
supporting information, p. 2033 - 2037 (2013/03/13)
A selective oxidation of benzylic C(sp3)-H bonds to C(sp 3)-O bonds catalyzed by copper complexes of quinoline-imine ligands was developed with peresters as oxidants under mild reaction conditions, which converted benzylic methylenes directly into benzylic alcohols and esters by means of direct C-H bond functionalization.
Protonated benzofuran, anthracene, naphthalene, benzene, ethene, and ethyne: Measurements and estimates of pKa and pKR
McCormack, Aoife C.,McDonnell, Claire M.,More O'Ferrall, Rory A.,O'Donoghue, AnnMarie C.,Rao, S. Nagaraja
, p. 8575 - 8583 (2007/10/03)
Aqueous solvolyses of acyl derivatives of hydrates (water adducts) of anthracene and benzofuran yield carbocations which undergo competitive deprotonation to form the aromatic molecules and nucleophilic reaction with water to give the aromatic hydrates. Trapping experiments with azide ions yield rate constants kp for the deprotonation and kH2O for the nucleophilic reaction based on the azide clock . Combining these with rate constants for (a) the H+-catalyzed reaction of the hydrate to form the carbocation and (b) hydrogen isotope exchange of the aromatic molecule (from the literature) yields pKR = -6.0 and -9.4 and pKa = -13.5 and -16.3 for the protonated anthracene and protonated benzofuran, respectively. These pK values may be compared with pKR = -6.7 for naphthalene hydrate (1-hydroxy-1,2-dihydronaphthalene), extrapolated to water from measurements by Pirinccioglu and Thibblin for acetonitrile-water mixtures, and pKa = -20.4 for the 2-protonated naphthalene from combining kp with an exchange rate constant. The differences between pKR and pKa correspond to pKH2O, the equilibrium constant for hydration of the aromatic molecule (pKH2O = pKR - pka). For naphthalene and anthracene values of pKH2O = +13.7 and +7.5 compare with independent estimates of +14.2 and +7.4. For benzene, pKa = -24.3 is derived from an exchange rate constant and an assigned value for the reverse rate constant close to the limit for solvent relaxation. Combining this pKa with calculated values of pKH2O gives pKR = -2.4 and -2.1 for protonated benzenes forming 1,2- and 1,4-hydrates, respectively. Coincidentally, the rate constant for protonation of benzene is similar to those for protonation of ethylene and acetylene (Lucchini, V.; Modena, G. J. Am. Chem Soc. 1990, 112, 6291). Values of pKa for the ethyl and vinyl cations (-24.8) may thus be derived in the same way as that for the benzenonium ion. Combining these with appropriate values of pKH2O then yields pKR = -39.8 and -29.6 for the vinyl and ethyl cations, respectively.
