24667-94-5Relevant academic research and scientific papers
An open metal site metal-organic framework Cu(BDC) as a promising heterogeneous catalyst for the modified Friedl?nder reaction
Phan, Nam T.S.,Nguyen, Tung T.,Nguyen, Khoa D.,Vo, Anh X.T.
, p. 128 - 135 (2013)
A crystalline porous metal-organic framework Cu(BDC) was synthesized, and characterized by several techniques, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), atomic absorption spectrophotometry (AAS), hydrogen temperature-programmed reduction (H2-TPR), and nitrogen physisorption measurements. The Cu(BDC) exhibited high catalytic activity for the modified Friedl?nder transformation using 2-aminobenzyl alcohol as the starting material, thus offering advantages over the conventional Friedl?nder reaction in terms of avoiding the problems associated with the storage of the highly unstable 2-aminobenzaldehyde. Moreover, the Cu(BDC) could offer significantly higher catalytic activity than that of other Cu-MOFs such as Cu3(BTC) 2, Cu(BPDC), and Cu2(BDC)2(DABCO). The catalyst could be recovered and reused several times without a significant degradation in catalytic activity. The modified Friedl?nder reaction could only occur in the presence of the solid Cu(BDC) with no contribution from leached active species.
Visible-Light-Mediated Oxidative Cyclization of 2-Aminobenzyl Alcohols and Secondary Alcohols Enabled by an Organic Photocatalyst
Xu, Jing-Xiu,Pan, Nan-Lian,Chen, Jia-Xi,Zhao, Jin-Wu
, p. 10747 - 10754 (2021/08/16)
This paper describes a visible-light-mediated oxidative cyclization of 2-aminobenzyl alcohols and secondary alcohols to produce quinolines at room temperature. This photocatalytic method employed anthraquinone as an organic small-molecule catalyst and DMSO as an oxidant. According to this present procedure, a series of quinolines were prepared in satisfactory yields.
Bioinspired Radical-Mediated Transition-Metal-Free Synthesis of N-Heterocycles under Visible Light
K. Bains, Amreen,Ankit, Yadav,Adhikari, Debashis
, p. 324 - 329 (2020/11/30)
A redox-active iminoquinone motif connected with π-delocalized pyrene core has been reported that can perform efficient two-electron oxidation of a class of substrates. The design of the molecule was inspired by the organic redox cofactor topaquinone (TPQ), which executes amine oxidation in the enzyme, copper amine oxidase. Easy oxidation of both primary and secondary alcohols happened in the presence of catalytic KOtBu, which could reduce the ligand backbone to its iminosemiquinonate form under photoinduced conditions. Moreover, this easy oxidation of alcohols under aerobic condition could be elegantly extended to multi-component, one-pot coupling for the synthesis of quinoline and pyrimidine. This organocatalytic approach is very mild (70 °C, 8 h) compared to a multitude of transition-metal catalysts that have been used to prepare these heterocycles. A detailed mechanistic study proves the intermediacy of the iminosemiquinonate-type radical and a critical hydrogen atom transfer step to be involved in the dehydrogenation reaction.
Iron catalyzed metal-ligand cooperative approaches towards sustainable synthesis of quinolines and quinazolin-4(3H)-ones
Mondal, Rakesh,Chakraborty, Gargi,Guin, Amit Kumar,Pal, Subhasree,Paul, Nanda D.
, (2021/10/12)
Herein we report simple, efficient, and economically affordable metal-ligand cooperative strategies for synthesizing quinolines and quinazolin-4(3H)-ones via dehydrogenative functionalization of alcohols. Various polysubstituted quinolines and quinazolin-4(3H)-ones were prepared in good yields via dehydrogenative coupling of readily available alcohols with ketones and 2-aminobenzamides, respectively under air using a well-defined Fe(II)-catalyst, ([FeL1Cl2] (1)) bearing a redox-active azo-aromatic pincer 2-((4-chlorophenyl)diazenyl)-1,10-phenanthroline) (L1). Control experiments and mechanistic investigation disclose that the one-electron reduced mono-anionic species [1]? bearing an iron-stabilized azo-anion radical ligand catalyzes these reactions. Both iron and the redox-active arylazo ligand participate synergistically during the different steps of these catalytic reactions.
Zinc Stabilized Azo-anion Radical in Dehydrogenative Synthesis of N-Heterocycles. An Exclusively Ligand Centered Redox Controlled Approach
Das, Siuli,Mondal, Rakesh,Chakraborty, Gargi,Guin, Amit Kumar,Das, Abhishek,Paul, Nanda D.
, p. 7498 - 7512 (2021/06/30)
Herein we report an exclusively ligand-centered redox controlled approach for the dehydrogenation of a variety of N-heterocycles using a Zn(II)-stabilized azo-anion radical complex as the catalyst. A simple, easy-to-prepare, and bench-stable Zn(II)-complex (1b) featuring the tridentate arylazo pincer, 2-((4-chlorophenyl)diazenyl)-1,10-phenanthroline, in the presence of zinc-dust, undergoes reduction to form the azo-anion radical species [1b]- which efficiently dehydrogenates various saturated N-heterocycles such as 1,2,3,4-tetrahydro-2-methylquinoline, 1,2,3,4-tetrahydro-isoquinoline, indoline, 2-phenyl-2,3-dihydro-1H-benzoimidazole, 2,3-dihydro-2-phenylquinazolin-4(1H)-one, and 1,2,3,4-tetrahydro-2-phenylquinazolines, among others, under air. The catalyst has further been found to be compatible with the cascade synthesis of these N-heterocycles via dehydrogenative coupling of alcohols with other suitable coupling partners under air. Mechanistic investigation reveals that the dehydrogenation reactions proceed via a one-electron hydrogen atom transfer (HAT) pathway where the zinc-stabilized azo-anion radical ligand abstracts the hydrogen atom from the organic substrate(s), and the whole catalytic cycle proceeds via the exclusive involvement of the ligand-centered redox events where the zinc acts only as the template.
Ruthenium complex and preparation method thereof and catalytic application
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Paragraph 0104-0106; 0109-0110, (2021/01/24)
The invention discloses a ruthenium complex and a preparation method thereof and catalytic application. The ruthenium complex is reported for the first time. Research finds that the ruthenium complexhas the activity of catalytically synthesizing quinazoline and derivatives thereof or catalytically synthesizing quinoline and derivatives thereof. When the ruthenium complex provided by the inventionis used for catalytic synthesis of quinazoline and derivatives thereof or quinoline and derivatives thereof, the ruthenium complex has the advantages of mild reaction conditions, wide substrate range, high catalytic product yield and good functional group tolerance, and is significantly superior to the prior art.
Method for synthesizing quinoline derivatives by copper catalysis
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Paragraph 0026-0031, (2021/03/24)
The invention relates to a method for synthesizing quinoline derivatives by copper catalysis. The method comprises the following steps: mixing 2-aminobenzyl alcohol, acetophenone derivatives, an alkaline reagent, a copper catalyst and a nitrogen-containing ligand in an organic solvent, and reacting at room temperature for 6-12h; and after the reaction is finished, sequentially carrying out concentration and column chromatography separation on the obtained reaction solution to obtain the corresponding quinoline derivative. Compared with the prior art, the method has the advantages that 2-aminobenzyl alcohol and acetophenone derivatives which are cheap and easy to obtain are used as raw materials, cuprous iodide CuI or cuprous bromide CuBr with stable properties is used as a catalyst, the quinoline skeleton-containing derivatives are directly constructed, use of toxic reagents is avoided, and the method conforms to the development concept of green chemistry; and the method has the advantages of simple operation, mild reaction conditions, good substrate universality and the like, and has huge application potential in the aspect of drug intermediate synthesis.
Designed pincer ligand supported Co(ii)-based catalysts for dehydrogenative activation of alcohols: Studies onN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines
Singh, Anshu,Maji, Ankur,Joshi, Mayank,Choudhury, Angshuman R.,Ghosh, Kaushik
, p. 8567 - 8587 (2021/06/30)
Base-metal catalystsCo1,Co2andCo3were synthesized from designed pincer ligandsL1,L2andL3having NNN donor atoms respectively.Co1,Co2andCo3were characterized by IR, UV-Vis. and ESI-MS spectroscopic studies. Single crystal X-ray diffraction studies were investigated to authenticate the molecular structures ofCo1andCo3. CatalystsCo1,Co2andCo3were utilized to study the dehydrogenative activation of alcohols forN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines. Under optimized reaction conditions, a broad range of substrates including alcohols, anilines and ketones were exploited. A series of control experiments forN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines were examined to understand the reaction pathway. ESI-MS spectral studies were investigated to characterize cobalt-alkoxide and cobalt-hydride intermediates. Reduction of styrene by evolved hydrogen gas during the reaction was investigated to authenticate the dehydrogenative nature of the catalysts. Probable reaction pathways were proposed forN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines on the basis of control experiments and detection of reaction intermediates.
A cobalt-catalyzed method for synthesizing quinoline and quinazoline compounds
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Paragraph 0011; 0036, (2022/01/10)
The present invention discloses a cobalt-catalyzed synthesis of quinoline and quinazoline compounds, by a benzene compound with amino and hydroxyl groups or benzonitrile compounds as raw materials, in the presence of a catalyst and a base by a receptor-fr
The preparation of a Co@C3N4catalyst and applications in the synthesis of quinolines from 2-aminobenzyl alcohols with ketones
Cao, Fei,Mao, Anruo,Yang, Bobin,Ge, Chenyang,Wang, Dawei
supporting information, p. 6768 - 6772 (2021/04/22)
An unsymmetrical diphenylphosphino-pyridinyl-triazole ligand was synthesized and characterized through IR, NMR and MS and the corresponding earth-abundant metal complex (cobalt) was prepared. Considering energy consumption and environmental friendliness, it is necessary to turn this diphenylphosphino-pyridinyl-triazole cobalt complex into a recyclable catalyst, which could easily be reused. Therefore, a heterogeneous catalyst was synthesized through Co-doping of C3N4, and the Co-nanoparticles on C3N4revealed high catalytic activity for the synthesis of quinolines with good recovery performance.
