نتایج جستجو برای: recyclable heterogeneous catalyst

تعداد نتایج: 168535  

Journal: :Nanoscale 2014
Man-Bo Li Shi-Kai Tian Zhikun Wu

An active, recoverable, and recyclable nanocluster catalyst, Au25(SR)18(-), has been developed to catalyze the formation of α,β-unsaturated ketones or aldehydes from propargylic acetates. The catalytic process has been proposed to be initialized by an SN2' addition of OH(-). Moreover, a dramatic solvent effect was observed, for which a rational explanation was provided.

Journal: :Chemical communications 2014
R Gangadhara Chary G Dhananjaya K Vara Prasad S Vaishaly Y S S Ganesh Balakrishna Dulla K Shiva Kumar Manojit Pal

A ligand/additive/Pd-free Cu-mediated coupling/cyclization strategy afforded the first practical, one-pot and general approach towards synthesis of N-(un)substituted isoquinolin-1(2H)-ones. Both the catalyst and the solvent used are recyclable. The use of the Cu reagent in excess led to the unusual formation of regioisomeric and uncommon isoquinolin-1(4H)-ones.

2015

The selective oxidation of hydrocarbons offers convenient synthetic routes for specialty chemicals, but also for widely used basic chemicals such as alcohols, aldehydes, ketones, epoxides or organic acids. Currently, the oxidation of alcohols is performed by metal oxides, which are hardly recyclable, or by organic oxidizing agents, which produce byproducts that are toxic or must be recycled.[1]...

Journal: :Molecules 2010
Ahmed Aouissi Zeid Abdullah Al-Othman Holeil Al-Anezi

The two heteropolyacids H(3)PW(12)O(40) and H(3)PMo(12)O(40), and their homologous salts (NH(4))(3)PW(12)O(40), and (NH(4))(3)PMo(12)O(40) were prepared and tested in the cationic polymerization of styrene. The results showed that the heteropolytungstates were more reactive than the heteropolymolybdates. It has been found that the yield and the viscosity average molecular weight (M(v)) of polys...

Journal: :Chemical communications 2009
Sung Hun Youk Sang Ho Oh Ho Sik Rho Je Eun Lee Ji Woong Lee Choong Eui Song

The design, synthesis, and catalytic application of a highly enantioselective and indefinitely stable polymer-supported Cinchona-based bifunctional sulfonamide is reported.

Abolghsem Davoodnia Ahmad Izadyar Hakimeh Mirzaee Hoseyn Eshghi

An efficient, recyclable and environmental-friendly synthetic route to polyhdroquinoline derivatives have been developed via multi-component one-pot Hantzsch reaction of various aromatic aldehyde, 2 equivalents of 5,5-dimethyl-1,3-cyclohexanedione (dimedone), ethyl acetoacetate and ammonium acetate using nano magnesium oxide as a catalyst in ethanol under reflux condition. Reaction with 4-chlor...

Journal: :Chemical communications 2014
Gil A B Gonçalves Sónia M G Pires Mário M Q Simões M Graça P M S Neves Paula A A P Marques

Three-dimensional graphene oxide foam (3DGO) was found to be a highly efficient and recyclable catalyst for the oxidation of thioanisole. We found that 3DGO is more efficient than 2DGO, and that the efficiency increases with the number of cycles for 3DGO, in contrast to the 2D counterpart.

Journal: :Chemical communications 2012
Amarajothi Dhakshinamoorthy Mercedes Alvaro Patricia Concepción Vicente Fornés Hermenegildo Garcia

The minute amount of hydrogen sulfate groups introduced into the graphene oxide (GO) obtained by Hummers oxidation of graphite renders this material as a highly efficient, recyclable acid catalyst for the ring opening of epoxides with methanol and other primary alcohols as nucleophile and solvent.

Journal: :Chemical communications 2007
Wing-Leung Wong Kwong-Chak Cheung Pak-Ho Chan Zhong-Yuan Zhou Kam-Han Lee Kwok-Yin Wong

A novel Re(I) complex covalently anchored with a pyrrolidinium moiety was successfully synthesized and used as an efficient and recyclable catalyst in the cycloaddition of CO2 with epoxides under mild reaction conditions to give excellent isolated yield and selectivity of cyclic carbonates in pyrrolidinium ionic liquid.

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