5388-47-6Relevant academic research and scientific papers
A Cu-Doped ZIF-8 metal organic framework as a heterogeneous solid catalyst for aerobic oxidation of benzylic hydrocarbons
Nagarjun, Nagarathinam,Dhakshinamoorthy, Amarajothi
supporting information, p. 18702 - 18712 (2019/12/09)
Mixed-metal metal organic frameworks have received considerable attention in recent years and it has been shown that the activity of the parent metal organic framework (MOF) is often enhanced upon doping with external metal ions within the framework. In this context, Cu2+ ions with different loadings were incorporated within the ZIF-8 framework to obtain a series of Cu-doped ZIF-8 materials and their activity was examined in the aerobic oxidation of hydrocarbons. The as-synthesized Cu-doped solids were characterized by powder X-ray diffraction (XRD), ultraviolet diffuse reflectance spectroscopy (UV-DRS), scanning electron microscopy (SEM), Fourier Transform infrared (FT-IR), electron paramagnetic resonance (EPR) and inductively coupled plasma (ICP) analysis. The experimental results revealed that the activity of Cu-doped ZIF-8 is much higher than that of the parent ZIF-8 in all the tested substrates at 120 °C. Furthermore, the activity of the Cu-doped ZIF-8 with the highest Cu loading was eight fold higher than that of the parent ZIF-8 in the aerobic oxidation of cyclooctane (1) at 120 °C with more than 80% selectivity to the corresponding cyclooctanol/cyclooctanone (ol/one) mixture. Cu-doped ZIF-8 was reused two times with no significant drop in its activity under identical conditions. Furthermore, comparison of the two times reused solid with that of the fresh solid by powder XRD and SEM analysis revealed identical structural integrity and morphology, respectively during the oxidation reactions.
Selective oxidation of saturated hydrocarbons using Au-Pd alloy nanoparticles supported on metal-organic frameworks
Long, Jilan,Liu, Hongli,Wu, Shijian,Liao, Shijun,Li, Yingwei
, p. 647 - 654 (2013/05/21)
Gold (Au) and palladium (Pd) nanoparticles dispersed on a zeolite-type metal-organic framework (i.e., MIL-101) were prepared via a simple colloidal method. The catalysts were characterized by powder X-ray diffraction, N 2 physical adsorption, atomic absorption spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Au and Pd were mostly in the form of bimetallic alloys on the MIL-101 support. The Au-Pd/MIL-101 was active and selective in the oxidation of a variety of saturated (including primary, secondary, and tertiary) C-H bonds with molecular oxygen. For the liquid-phase oxidation of cyclohexane, cyclohexane conversion exceeding 40% was achieved (TOF: 19 000 h-1) with >80% selectivity to cyclohexanone and cyclohexanol under mild solvent-free conditions. Moreover, the Au-Pd alloy catalyst exhibited higher reactivity than their pure metal counterparts and an Au + Pd physical mixture. The high activity and selectivity of Au-Pd/MIL-101 in cyclohexane aerobic oxidation may be correlated to the synergistic alloying effect of bimetallic Au-Pd nanoparticles.
Molecular addition compounds. 14. Convenient preparations of representative dialkylborane reagents using the new, highly reactive N- ethyl-N-isopropylaniline-borane reagent (BACH-EI(TM))
Brown, Herbert C.,Kanth, Josyula V. B.,Zaidlewicz, Marek
, p. 5991 - 6000 (2007/10/03)
Convenient procedures for the preparation of representative dialkylborane reagents, diisopinocampheylborane, [1S]-2-diisocaranylborane, 9-borabicyclo[3,3,1]nonane, dicyclohexylborane and disiamylborane, using the new, highly reactive N-ethyl-N-isopropylaniline-borane reagent (BACH-EI(TM)) in dioxane and tetrahydrofuran are described.
Catalytic Reactions of Metalloporphyrins. 3. Catalytic Modification of Hydroboration-Oxidation of Olefin with Rhodium(III) Porphyrin as Catalyst
Aoyama, Yasuhiro,Tanaka, Yasutaka,Fujisawa, Takeshi,Watanabe, Takamichi,Toi, Hiroo,Ogoshi, Hisanobu
, p. 2555 - 2559 (2007/10/02)
(Octaethylporphyrinato)- or (tetraphenylporphyrinato)rhodium(III) chloride catalyzes the anti-Marcovnikov "hydration" of olefin with NaBH4 and O2 in THF. 1,5-Cyclooctadiene gives rise to cyclooctanol and 1,5-cyclooctanediol (in a ratio of approximately 1:2), and acetylenes are converted directly to alcohols under similar conditions.The initial step in the catalytic reaction of olefin is the hydride and borane transfers from BH4- respectively to RhIII porphyrin and olefin to give hydridorhodium (RhH) porphyrin and alkylborane.The RhH species undergoesoxidation with O2 back to RhIII with concomitant oxidation of alkylborane with retention of configuration.This coupled oxidation of alkylborane is in competition with its nonstereospecific autooxidation without assistance of Rh-H.The present system provides a catalytic modification of hydroboration-oxidation of olefin in the presence of oxygen, as illustrated by the one-pot conversion of 1-methylcyclohexene to (E)-2-methylcyclohexanol with 100 percent regioselectivity and up to 97 percent stereoselectivity.
Vinyl Epoxide Hydrolysis Reactions
Ross, Angela M.,Pohl, Terese M.,Piazza, Kathryn,Thomas, Michael,Fox, Bonnie,Whalen, Dale L.
, p. 1658 - 1665 (2007/10/02)
The rates of hydrolysis of cyclopentadiene oxide (3), cyclohexadiene oxide (4), cycloheptadiene oxide (5), cyclooctadiene oxide (6), butadiene oxide (7), and styrene oxide (8) have been determined as a function of pH.Each epoxide exhibited acid-catalyzed hydrolysis at low pH, and 3-5 showed significant rates for "spontaneous" reaction with solvent at intermediate pH values.The hydrolyses of several of the vinyl epoxides (4 and 5) showed kinetic terms in HO- at pH > ca. 13.Specific chloride effects attributed to nucleophilic addition of Cl- to neutral epoxide were observed for those compounds (3, 4, and 8) hydrolyzed in KCl solutions.From kinetic and product studies, mechanisms for hydrolyses of the vinyl epoxides are postulated.Acid-catalyzed hydrolyses of 3, 4, 5, and 6 were found to be A-1 in nature, proceeding via intermediate allyl cations.Product distributions depended on the structure of the cation.Mechanisms and product distributions for the spontaneous hydrolyses of vinyl epoxides were found to be variable, and dependent on the structure of the epoxide.
