The Experts below are selected from a list of 43599 Experts worldwide ranked by ideXlab platform
Decai Fang - One of the best experts on this subject based on the ideXlab platform.
-
catalytic c h activation c c Coupling Reaction dft studies on the mechanism solvent effect and role of additive
Journal of Organic Chemistry, 2013Co-Authors: Lei Zhang, Decai FangAbstract:A series of density functional theory (DFT) experiments, employing the B3LYP+IDSCRF/BS1 and B3LYP+IDSCRF/DZVP methods, have been carried out for the Pd(OAc)2-catalyzed enamide–siloxane C–H activation/C–C Coupling Reactions. The results reveal that there are four processes, namely C–H activation, transmetalation (TM), reductive elimination (RE), and separation of product (SP) and recycling of catalyst (RC), each of which is consist of different steps. In order to fully understand the origin of regiospecific C–H activation/C–C Coupling on the alicyclic ring experimentally observed, the conformational preference, kinetic aspects, and relative stabilities of the competitive products have been explored. In addition, the roles of additive silver salt AgF and solvent dioxane have also been addressed, providing valuable details upon which to rationally optimize experimental conditions.
-
Catalytic C–H Activation/C–C Coupling Reaction: DFT Studies on the Mechanism, Solvent Effect, and Role of Additive
The Journal of organic chemistry, 2013Co-Authors: Lei Zhang, Decai FangAbstract:A series of density functional theory (DFT) experiments, employing the B3LYP+IDSCRF/BS1 and B3LYP+IDSCRF/DZVP methods, have been carried out for the Pd(OAc)2-catalyzed enamide–siloxane C–H activation/C–C Coupling Reactions. The results reveal that there are four processes, namely C–H activation, transmetalation (TM), reductive elimination (RE), and separation of product (SP) and recycling of catalyst (RC), each of which is consist of different steps. In order to fully understand the origin of regiospecific C–H activation/C–C Coupling on the alicyclic ring experimentally observed, the conformational preference, kinetic aspects, and relative stabilities of the competitive products have been explored. In addition, the roles of additive silver salt AgF and solvent dioxane have also been addressed, providing valuable details upon which to rationally optimize experimental conditions.
Zhigang Zou - One of the best experts on this subject based on the ideXlab platform.
-
An in situ simultaneous reduction-hydrolysis technique for fabrication of TiO2-graphene 2D sandwich-like hybrid nanosheets: Graphene-promoted selectivity of photocatalytic-driven hydrogenation and Coupling of CO 2 into methane and ethane
Advanced Functional Materials, 2013Co-Authors: Wenguang Tu, Shanshan Bao, Shicheng Yan, Xiaoyong Wang, Qi Liu, Yong Zhou, Min Xiao, Zhigang ZouAbstract:A novel, in situ simultaneous reduction-hydrolysis technique (SRH) is developed for fabrication of TiO 2 --graphene hybrid nanosheets in a binary ethylenediamine (En)/H 2 O solvent. The SRH technique is based on the mechanism of the simultaneous reduction of graphene oxide (GO) into graphene by En and the formation of TiO 2 nanoparticles through hydrolysis of titanium (IV) (ammonium lactato) dihydroxybis, subsequently in situ loading onto graphene through chemical bonds (Ti–O–C bond) to form 2D sandwich-like nanostructure. The dispersion of TiO 2 hinders the collapse and restacking of exfoliated sheets of graphene during reduction process. In contrast with prevenient G-TiO 2 nanocomposites, abundant Ti 3 + is detected on the surface of TiO 2 of the present hybrid, caused by reducing agent En. The Ti 3 + sites on the surface can serve as sites for trapping photogenerated electrons to prevent recombination of electron–hole pairs. The high photocatalytic activity of G-TiO 2 hybrid is confi rmed by photocatalytic conversion of CO 2 to valuable hydrocarbons (CH 4 and C 2 H 6 ) in the presence of water vapor. The synergistic effect of the surface-Ti 3 + sites and graphene favors the generation of C 2 H 6 , and the yield of the C 2 H 6 increases with the content of incorporated graphene. The work may open a new doorway for new signifi cant application of graphene for selectively catalytic C–C Coupling Reaction
Matthias Wagner - One of the best experts on this subject based on the ideXlab platform.
-
a boron doped helicene as a highly soluble benchtop stable green emitter
Chemical Communications, 2015Co-Authors: Kai Schickedanz, Michael Bolte, Hans-wolfram Lerner, Timo Trageser, Matthias WagnerAbstract:The high-yield synthesis of a boron-doped [4]helicene was achieved through a Ni-mediated Yamamoto C-C-Coupling Reaction; the moderate distortion of the molecular scaffold confers excellent solubility to the air- and water-stable green luminophore.
-
synthesis of bromo boryl and stannyl functionalized 1 2 bis trimethylsilyl benzenes via diels alder or c h activation Reactions
Journal of Organic Chemistry, 2012Co-Authors: Christian Reus, Michael Bolte, Hans-wolfram Lerner, Matthias WagnerAbstract:1,2-Bis(trimethylsilyl)benzenes are key starting materials for the synthesis of benzyne precursors, Lewis acid catalysts, and certain luminophores. We have developed efficient, high-yield routes to functionalized 4-R-1,2-bis(trimethylsilyl)benzenes, starting from either 1,2-bis(trimethylsilyl)acetylene/5-bromopyran-2-one (2) or 1,2-bis(trimethylsilyl)benzene (1)/bis(pinacolato)diborane. In the first Reaction, 5 (R = Br) is obtained through a cobalt-catalyzed Diels–Alder cycloaddition. The second Reaction proceeds via iridium-mediated C–H activation and provides 8 (R = Bpin). Besides its use as a Suzuki reagent, compound 8 can be converted into 5 with CuBr2 in i-PrOH/MeOH/H2O. Lithium–bromine exchange on 5, followed by the addition of Me3SnCl, gives 10 (R = SnMe3), which we have applied for Stille Coupling Reactions. A Pd-catalyzed C–C Coupling Reaction between 5 and 8 leads to the corresponding tetrasilylbiphenyl derivative. The bromo derivative 5 cleanly undergoes Suzuki Reactions with electron-rich as w...
Rénal Backov - One of the best experts on this subject based on the ideXlab platform.
-
Bulk Photodriven CO 2 Conversion through TiO 2 @Si(HIPE) Monolithic Macrocellular Foams
Advanced Functional Materials, 2019Co-Authors: Sophie Bernadet, Eugénie Tavernier, Renaud Vallée, Serge Ravaine, Antoine Fecant, Rénal BackovAbstract:Operating photo‐induced Reactions exclusively on catalyst surfaces while not exploiting the full catalyst volume generates a major footprint penalty for the photocatalytic reactor and leads to an inefficient use of the catalytic material. Photonic investigations clearly show that the solid foams have a strongly multidiffusive character, with photons being significantly trapped within the sample cores while addressing a photon mean free path lt = 20.1 ± 1.3 µm. This 3D process both greatly limits back‐Reactions and promotes outstanding selectivity toward methane (around 80%) generation, and even ethane (around 18%) through C‐C Coupling Reaction, with residual carbon monoxide and dihydrogen contents (around 2%). Silica–titania TiO2@Si(HIPE) self‐standing macrocellular catalysts lead to optimal efficient thicknesses up to 20 times those of powders, thereby enhancing the way for real 3D‐photodriven catalytic processes above the millimeter scale and up to a 6 mm thickness. A rather simple Langmuir–Hinshelwood based kinetic model is proposed which highlights the strong dependence of photocatalytic Reaction rates on light scattering and the crucial role on oxidation back‐Reactions. In addition, a strong correlation between light attenuation coefficient and photon mean free path and median pore aperture diameter is demonstrated, offering thus a tool for photocatalytic behavior prediction.
Lei Zhang - One of the best experts on this subject based on the ideXlab platform.
-
catalytic c h activation c c Coupling Reaction dft studies on the mechanism solvent effect and role of additive
Journal of Organic Chemistry, 2013Co-Authors: Lei Zhang, Decai FangAbstract:A series of density functional theory (DFT) experiments, employing the B3LYP+IDSCRF/BS1 and B3LYP+IDSCRF/DZVP methods, have been carried out for the Pd(OAc)2-catalyzed enamide–siloxane C–H activation/C–C Coupling Reactions. The results reveal that there are four processes, namely C–H activation, transmetalation (TM), reductive elimination (RE), and separation of product (SP) and recycling of catalyst (RC), each of which is consist of different steps. In order to fully understand the origin of regiospecific C–H activation/C–C Coupling on the alicyclic ring experimentally observed, the conformational preference, kinetic aspects, and relative stabilities of the competitive products have been explored. In addition, the roles of additive silver salt AgF and solvent dioxane have also been addressed, providing valuable details upon which to rationally optimize experimental conditions.
-
Catalytic C–H Activation/C–C Coupling Reaction: DFT Studies on the Mechanism, Solvent Effect, and Role of Additive
The Journal of organic chemistry, 2013Co-Authors: Lei Zhang, Decai FangAbstract:A series of density functional theory (DFT) experiments, employing the B3LYP+IDSCRF/BS1 and B3LYP+IDSCRF/DZVP methods, have been carried out for the Pd(OAc)2-catalyzed enamide–siloxane C–H activation/C–C Coupling Reactions. The results reveal that there are four processes, namely C–H activation, transmetalation (TM), reductive elimination (RE), and separation of product (SP) and recycling of catalyst (RC), each of which is consist of different steps. In order to fully understand the origin of regiospecific C–H activation/C–C Coupling on the alicyclic ring experimentally observed, the conformational preference, kinetic aspects, and relative stabilities of the competitive products have been explored. In addition, the roles of additive silver salt AgF and solvent dioxane have also been addressed, providing valuable details upon which to rationally optimize experimental conditions.
