38401-67-1Relevant articles and documents
Regioselective double Suzuki couplings of 4,5-dibromothiophene-2-carboxaldehyde
Handy, Scott T.,Mayi, Diyar
, p. 8108 - 8110 (2007)
Conditions have been identified that enable the one-pot double Suzuki coupling of 4,5-dibromothiophene-2-carboxaldehyde to proceed in good yield. The key to success in these reactions is the use of minimal amounts of water to avoid significant amounts of
Beta-amyloid protein targeting fluorescent probe, preparation and application of beta-amyloid protein targeting fluorescent probe in Alzheimer's disease
-
Paragraph 0109; 0253-0257, (2021/06/09)
The invention discloses a beta-amyloid protein targeting fluorescent probe, preparation and application of the beta-amyloid protein targeting fluorescent probe in Alzheimer's disease. The structural formula of the fluorescent probe is as shown in formula I in the specification. The fluorescent probe disclosed by the invention is a compound taking 6-dimethylamino-1-methylquinoline as a parent structure, and the fluorescent probe has the advantages of long emission wavelength, large Stock shift, capability of specifically detecting beta amyloid protein, sensitivity to viscosity in tissue cells, and good response to the viscosity. After the fluorescent probe is combined with beta amyloid protein in the brain of a patient suffering from the Alzheimer's disease, a fluorescence signal is obviously enhanced, and the fluorescent probe can be used for detecting the beta amyloid protein and early diagnosing the Alzheimer's disease and has important guiding significance on development of diagnosis and treatment probes of the Alzheimer's disease.
Air-stable Pd(0) catalyst bearing dual phosphine ligands: a detailed evaluation of air stability and catalytic property in cross-coupling reactions
Sato, Ryota,Kanbara, Takaki,Kuwabara, Junpei
, p. 12814 - 12819 (2020/10/02)
We have synthesised an air-stable Pd(0) catalyst bearing donor and acceptor phosphine ligands (Complex1). This study revealed the long-term air stability and catalytic property of Complex1as a catalyst for cross-coupling reactions, where it was stable in air for eight months. DFT calculations revealed that the acceptor ligands in Complex1decreased the HOMO energy level, which provided the observed air stability. Complex1successfully served as a catalyst for direct C-H arylation reactions and Suzuki-Miyaura cross-coupling reactions, and catalysed the reaction of a relatively inactive substrate, 2-chrolopyridine, which could not be achieved by conventional, air-stable Pd(0) catalysts. Isolating the intermediates of the coupling reactions revealed that each intermediate possessed the donor ligand (PCy3), which was determined to be responsible for imparting the high catalytic activity exhibited by Complex1.
Synthesis of an Air-Stable Pd(0) Catalyst Bearing Donor and Acceptor Phosphine Ligands
Kanbara, Takaki,Kuwabara, Junpei,Sato, Ryota
supporting information, (2020/02/04)
We synthesized a new Pd(0) complex bearing π-acceptor ligands and a σ-donor ligand and confirmed that it exhibits high air stability and catalytic activity in direct arylation reactions. Moreover, stoichiometric reactions of the complex revealed that the σ-donor ligand does not dissociate from the Pd center.
Novel 2-(5-aryl)thiophen-2-yl)benzimidazoles; design, synthesis and in vitro evaluation against cercarial phase of schistosoma mansoni
El Bialy, Serry A.,Mansour, Basem,Bayoumi, Waleed A.,Taman, Amira,Eissa, Hassan M.
, p. 1432 - 1438 (2020/10/06)
Background: Literature survey has pointed out that Benzimidazoles represent an interesting class of anthelmintics, of which several potent members were developed. Objective: Benzimidazoles hybridized with pharmacophoric moieties possessing anthelmintic ac
Design, synthesis and evaluation of phenylthiazole and phenylthiophene pyrimidindiamine derivatives targeting the bacterial membrane
Chen, Yihua,Fan, Tingting,Guo, Weikai,Hu, Pan,Liu, Mingyao,Shao, Ting,Yi, Zhengfang,Zhou, Wenbo
, (2020/02/20)
As the continuous rise in the incidence of antibiotic resistance, it is urgent to develop novel chemical scaffolds with antibacterial activities to control the spread of resistance to conventional antibiotics. In this study, a series of phenylthiazole and
From agriculture residue to catalyst support; A green and sustainable cellulose-based dip catalyst for C–C coupling and direct arylation
Kandathil, Vishal,Kempasiddaiah, Manjunatha,B. S., Sasidhar,Patil, Siddappa A.
, (2019/07/31)
The core characteristics of a perfect catalyst include good activity, simple design, excellent stability, easy recovery from reaction mixture, recyclability, and have the provision for easy scale up. The ease in synthesis, recyclability and scale up makes the dip catalyst a major contender in this regard which possess most of the aforementioned characteristics. In this work, we report a dip catalyst made of cellulose, isolated from agriculture residue (sugarcane bagasse), in which biogenically synthesized palladium nanoparticles were dispersed. The prepared dip catalyst was characterized by FESEM, EDS, XRD, ATR-IR, TGA, TEM, XPS and ICP-OES analysis. Also, the activity of the dip catalyst was studied in the Suzuki-Miyaura cross-coupling reaction and was found to give excellent conversion with 15 recycles. Further, the activity of dip catalyst in C5-arylation of 2-substituted thiophenes was evaluated for which promising yields were obtained.
Catalytic Deprotonative α-Formylation of Heteroarenes by an Amide Base Generated in Situ from Tetramethylammonium Fluoride and Tris(trimethylsilyl)amine
Shigeno, Masanori,Fujii, Yuki,Kajima, Akihisa,Nozawa-Kumada, Kanako,Kondo, Yoshinori
, p. 443 - 451 (2019/04/30)
Heteroarene formylations in DMF solution proceed in the presence of an amide base catalyst generated in situ from tetramethylammonium fluoride (TMAF) and tris(trimethylsilyl)amine (N(TMS)3). The reaction proceeds at room temperature and has an operationally simple procedure. Various heteroarenes, including benzothiophene, thiophene, benzothiazole, oxazole, and indole derivatives, can be formylated with high functional group tolerance.
Role of pyridine nitrogen in palladium-catalyzed imine hydrolysis: A Case Study of (E)-1-(3-bromothiophen-2-yl)-N-(4-methylpyridin-2-yl)methanimine
Ahmad, Gulraiz,Rasool, Nasir,Rizwan, Komal,Altaf, Ataf Ali,Rashid, Umer,Hussein, Mohd Zobir,Mahmood, Tariq,Ayub, Khurshid
, (2019/08/01)
In the present study, 4-methylpyridin-2-amine was reacted with 3-bromothiophene-2-carbaldehyde and the Schiff base (E)-1-(3-bromothiophen-2-yl)-N-(4-methylpyridin-2-yl) methanimine was obtained in a 79% yield. Coupling of the Schiff base with aryl/het-aryl boronic acids under Suzuki coupling reaction conditions, using Pd(PPh3)4 as catalyst, yielded products with the hydrolysis of the imine linkages (5a–5k, 6a–6h) in good to moderate yields. To gain mechanistic insight into the transition metal-catalyzed hydrolysis of the compounds, density functional theory (DFT) calculations were performed. The theoretical calculations strongly supported the experiment and provided an insight into the transition metal-catalyzed hydrolysis of imines.
Metal-Free Aerobic Oxidative Selective C-C Bond Cleavage in Heteroaryl-Containing Primary and Secondary Alcohols
Xia, Anjie,Qi, Xueyu,Mao, Xin,Wu, Xiaoai,Yang, Xin,Zhang, Rong,Xiang, Zhiyu,Lian, Zhong,Chen, Yingchun,Yang, Shengyong
supporting information, (2019/05/07)
A transition-metal-free aerobic oxidative selective C-C bond-cleavage reaction in primary and secondary heteroaryl alcohols is reported. This reaction was highly efficient and tolerated various heteroaryl alcohols, generating a carboxylic acid derivative and a neutral heteroaromatic compound. Experimental studies combined with density functional theory calculations revealed the mechanism underlying the selective C-C bond cleavage. This strategy also provides an alternative simple approach to carboxylation reaction.
