- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Synthesis of 3,4-Biaryl-2,5-Dichlorothiophene through Suzuki Cross-Coupling and Theoretical Exploration of Their Potential Applications as Nonlinear Optical Materials
摘要： We report herein the efficient one-pot synthesis of 3,4-biaryl-2,5-dichlorothiophene derivatives (2a–2i) via a palladium-catalyzed Suzuki cross-coupling reaction. A series of thiophene derivatives were synthesized, starting from 3,4-dibromo-2,5-dichlorothiophene (1) and various arylboronic acids using Pd(PPh3)4 and K3PO4 with moderate to good yields. For further insights about the structure and property relationship, density functional theory (DFT) calculations were performed. A relaxed potential energy surface (PES) scan was performed to locate the minimum energy structure. A frontier molecular orbitals analysis was performed to explain the reactivity of all synthesized derivatives. As the synthesized derivatives had extended conjugations, therefore the first hyperpolarizability (βo) was calculated to investigate their potential as non-linear optical (NLO) materials and significant βo values were found for the 2b and 2g derivatives.
关键词： NLO,Pd (PPh3)4,thiophene,PES,density functional theory,Suzuki cross-coupling reaction
更新于2025-09-23 15:22:29
-
Heterogeneous photocatalyzed C-C cross-coupling reactions under visible-light and near-infrared light irradiation
摘要： With the development of photocatalytic technology and organic synthesis chemistry, the photocatalyzed cross-coupling reaction provides one of the most attractive methodologies for the C-C bond formation and has been booming in recent years. The advantages of the heterogeneous photocatalyzed C-C cross-coupling reaction lie in its environment friendly, easily separated and conveniently recovered catalysts. In this review, we summarized and highlighted recent achievements of heterogeneous photocatalyzed C-C cross-coupling reactions through four aspects: visible light induced C-C cross-coupling reactions catalyzed by Pd supported semiconductor photocatalysts; visible light induced C-C cross-coupling reactions catalyzed by Pd based plasmonic photocatalysts; visible light induced C-C cross-coupling reactions catalyzed by palladium-free photocatalysts; near-infrared light induced C-C cross-coupling reactions.
关键词： Photocatalysis,semiconductor,C-C cross-coupling,localized surface plasmon resonance,Pd
更新于2025-09-23 15:21:21
-
Application of experimental design and multivariate analysis in the on-line reaction monitoring of a Suzuki cross-coupling reaction by Raman spectroscopy and multivariate analysis
摘要： A Suzuki-coupling reaction for the construction of CeC bond was monitored using Raman spectroscopy. The effects of temperature and concentration on the reaction yield were investigated following a central composite design. The percent yield for each data was measured off-line using GCeMS. On-line monitoring reactions using Raman spectroscopy coupled with partial least squares (PLS) were used for building a prediction model. Raman spectra collected from five experiments at different sampling times were used in building the model. The PLS model was then validated and results showed that the yield of reaction can be predicted well with high accuracy by the model, both within and outside the experimental limits. The results presented here have shown that such model is well suited for monitoring Suzuki-coupling reactions that are widely used in chemical and pharmaceutical industries.
关键词： Raman spectroscopy,Multivariate data analysis,Reaction monitoring,Suzuki cross-coupling
更新于2025-09-23 15:21:21
-
Biaryl Crossa??Coupling Enabled by Photoa??Induced Electron Transfer
摘要： We report a protocol for aryl cross-coupling of electron-deficient aryl halides with electron-rich (hetero)arenes that is driven solely by violet light. This process takes advantage of formation of photo-excited state of electron-deficient aryl halides, that are reduced by electron-rich (hetero)arenes to form a pair of aryl anion and cation radicals. The resulting aryl anion radicals of aryl halides undergo mesolysis of the carbon-halogen bond to generate aryl radicals, that are coupled most likely with aryl cation radicals to afford functionalized biaryls.
关键词： Single-electron-transfer,Visible light,Anion radicals,Aryl radicals,Cross-coupling
更新于2025-09-23 15:21:01
-
A Facile Approach to the Synthesis of n-Type π-Conjugated Hyperbranched Polymers
摘要： A facile approach for the synthesis of an n-type π-conjugated hyperbranched polymer, namely hyperbranched polypyridinebenzene, is proposed based on the copolymerization of 1,3,5-tribromobenzene (BeBr3) and 2,5-dibromopyridine via chain-growth condensation polymerization catalyzed by Ni(dppp)Cl2. The use of BeBr3 as a branching unit simplifies the synthesis of n-type π-conjugated hyperbranched polymers, compared with a similar hyperbranched polymer prepared from 2,4,6-tribromopyridine (PyBr3) and 2,5-dibromopyridine requiring a lengthy synthetic route to give the starting material PyBr3. The results of UV-Vis spectroscopy and cyclic voltammetry suggest that our synthesized polymer retains its hyperbranched structure, which is beneficial in electrochemical doping.
关键词： Cross-coupling,Doping,Polypyridine,Chain-growth condensation
更新于2025-09-23 15:21:01
-
Plasmonic heating using an easily recyclable Pda??functionalized Fe <sub/>3</sub> O <sub/>4</sub> /Au corea??shell nanoparticle catalyst for the Suzuki and Sonogashira reaction
摘要： Palladium functionalized gold nanoparticles were used in the past as a catalyst system in light induced cross-coupling reactions, but with a main limitation of the recuperation. To overcome this problem, a palladium functionalized Fe3O4/Au core-shell nanoparticle was successfully synthesized with a peak wavelength of 680 nm from the plasmon resonance of the gold shell. By the presence of the magnetite core, the nanoparticle catalyst can easily be removed using magnetic precipitation. This is accompanied with the advantage of having less valuable gold present in the system. The gold shell makes it possible to induce local heating using plasmon resonance. By this combination, it is possible to recuperate the catalyst system using magnetic precipitation and increase the control and safety of the reaction due to the presence of the light-induced plasmonic heating. It was possible to perform light-induced Suzuki cross-coupling reactions using this catalyst system, but with a dependency of the substrate. It was found that an anionic substrate is repulsed from the negatively charged core-shell nanoparticle. The catalyst was examined on its recuperation abilities and could be reused up to 5 cycles. At the catalytic site a temperature was reached between 40 °C and 45 °C. Despite the promising results of the Suzuki reaction, it was not possible to perform light-induced Sonogashira reactions due to the insufficient heat generation at the catalytic site. Nevertheless, these results are promising in the development of an easily recyclable catalyst together with an alternative heating source, resulting in an increase of control and safety.
关键词： cross-coupling reaction,magnetically separable,plasmonic heating,immobilized catalyst
更新于2025-09-23 15:19:57
-
Growth of single crystalline GePb film on Ge substrate by magnetron sputtering epitaxy
摘要： A novel direct synthesis of 1,3-dioxo-substituted allenes was developed by copper(I)-catalyzed coupling of a-oxo-alkynes and a-oxo-diazos. It was a sequence of adding substrates-controlled method and the desired products were synthesized chemoselectively by adding a-oxo-alkyne terminally.
关键词： Alkynes,Cross-coupling,Allenes,Copper catalyst,Diazo compounds
更新于2025-09-19 17:15:36
-
A four-state fluorescent molecular switch
摘要： Cross-coupling reactions are among the most powerful C–C and C–X bond forming tools in organic chemistry. Traditionally, cross-coupling methods rely on the use of aryl halides or pseudohalides as electrophiles. In the past three years, decarbonylative cross-couplings of amides have emerged as an attractive method for the construction of a wide variety of carbon–carbon and carbon–heteroatom bonds, allowing for the synthetically-valuable functional group inter-conversion of the amide bond. These previously elusive reactions hinge upon selective activation of the N–C(O) acyl amide bond, followed by CO extrusion, in a formal double N–C/C–C bond activation, to generate a versatile aryl–metal intermediate as an attractive alternative to traditional cross-couplings of aryl halides and pseudohalides. In this perspective review, we present recent advances and key developments in the field of decarbonylative cross-coupling reactions of amides as well as discuss future challenges and potential applications for this exciting field.
关键词： amides,transition-metal catalysis,C–C bond formation,decarbonylative cross-coupling,C–X bond formation
更新于2025-09-19 17:15:36
-
Diarylpyrazine-based position isomers: A detailed study of optical properties and structure-property relationship
摘要： A versatile and expeditious synthetic route to pyrazine-based symmetric and asymmetric chromophores decorated with donor-acceptor (D-A) has been designed to study their structural effects on optical properties. Suzuki-Miyaura coupling of dihalopyrazine with various aryl boronic acids was synthesized under microwave condition. Pyrazine functionalized at C-2, C-5 and C-6 serve as acceptor to construct linear and angular push-pull chromophores. The photophysical, electrochemical and thermal properties of all the target chromophores were systematically investigated and the results were correlated theoretically by density functional theory computations. The emission wavelength was significantly red-shifted by introduction of strong electron withdrawing group (CN). The permutation of terminal donor acceptor units tunes the optoelectronic properties in a predictable way, aiding in the rational design of small molecule for luminescent materials. These chromophores displayed multicolor change in different solvents, exhibiting good solvatochromism with a large Stokes shift.
关键词： solvatochromism.,cross-coupling,Diarylpyrazine,intramolecular charge transfer
更新于2025-09-19 17:13:59
-
Fluorescent 2-(pyridin-2-yl)vinyl pyridine dyes and their thermo-controlled release
摘要： The generation of unique thermosensitive fluorescent dyes via heteroaromatic Heck cross-coupling and N-pyridin-2-yl nucleophilic substitution was described. To demonstrate thermosensitive properties, the precursor was converted into carbonate or phosphate and heating at various temperatures and times of heating. Significant changes in fluorescence intensity and emission wavelengths, between carbonates and the cyclic product, were observed and proved that dyes may serve as removable fluorescent labels with large Stokes shifts (>80 nm). Application of thermosensitive fluorescent dyes in oligonucleotide labelling has been demonstrated.
关键词： Heck cross-coupling,large Stokes shifts,N-pyridin-2-yl nucleophilic substitution,thermosensitive fluorescent dyes,oligonucleotide labelling
更新于2025-09-16 10:30:52