25855-20-3Relevant academic research and scientific papers
2-Chloroquinazoline. Synthesis and reactivity of a versatile heterocyclic building block
Henriksen, Signe Teuber,S?rensen, Ulrik Svane
, p. 8251 - 8254 (2006)
Starting from 2,4-dichloroquinazoline, various methods for the selective removal of the 4-chloro substituent were tested, including catalytic hydrogenation, metal-halogen exchange, metal hydride reduction and reduction with tributyltin hydride-the latter
Method for catalyzing nitrogen heterocyclic ring aerobic dehydrogenation based on ionic liquid porous carbon material
-
Paragraph 0057-0060, (2022/01/24)
The invention discloses a method for catalyzing nitrogen heterocycle aerobic dehydrogenation based on an ionic liquid porous carbon material, and is suitable for the field of organic synthesis. A heterogeneous catalysis system takes nitrogen heterocycle and derivatives thereof as substrates, a carbon material as a catalyst, water or ethanol as a solvent and air or oxygen spheres as an oxygen source, and a reaction is carried out at 0-80 DEG C under normal pressure, oxidative dehydrogenation of nitrogen heterocyclic compounds can be realized, and target products such as indole, quinoline, isoquinoline, quinazoline, quinoxaline, benzothiazole, Hanus ester and derivatives thereof and other medical intermediates can be synthesized. The non-metal catalyst is prepared by using the ionic liquid as the precursor, no activating agent or other additives are used in the reaction process, and the method has industrial application prospects.
BTP-Rh@g-C3N4 as an efficient recyclable catalyst for dehydrogenation and borrowing hydrogen reactions
Luo, Lan,Liu, Hongqiang,Zeng, Wei,Hu, Wenkang,Wang, Dawei
, (2021/11/16)
Highly active catalysts play an important role in modern catalysis. A novel and efficient ligand benzotriazole-pyrimidine (BTP) and the corresponding rhodium composite on C3N4 were successfully synthesized. The resulting rhodium composite was fully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), thermogravimetric analysis (TGA), and x-ray photoelectron spectroscopy (XPS). The obtained composite exhibited good catalytic activity and good recovery performance in the synthesis of quinoxaline from 2-aminobenzyl alcohol and benzonitrile, and more than 20 quinoxalines were obtained in good yields. Additionally, it also showed that rhodium composite could achieved good catalytic performance in the synthesis of functionalized ketone through borrowing hydrogen strategy.
Type I ‘Lighted Metal-free’ Photosensitizing Assemblies of Phenazine for Aerobic Oxidative Transformations
Kaur, Lovjot,Kaur, Harpreet,Kumar, Manoj,Bhalla, Vandana
supporting information, p. 4179 - 4186 (2021/11/23)
Highly photostable supramolecular photosensitizing ‘lighted metal-free’ assemblies of DPZ-Th have been developed which show strong absorption in the visible region and excellent electron transportation potential from donor to acceptor units. The as-prepar
Visible-light-mediated organoboron-catalysed metal-free dehydrogenation of N-heterocycles using molecular oxygen
Wei, Lanfeng,Wei, Yu,Xu, Liang,Zhang, Jinli
supporting information, p. 4446 - 4450 (2021/06/30)
The surge of photocatalytic transformation not only provides unprecedented synthetic methods, but also triggers the enthusiasm for more sustainable photocatalysts. On the other hand, oxygen is an ideal oxidant in terms of atom economy and environmental friendliness. However, the poor reactivity of oxygen at the ground state makes its utilization challenging. Herein, a visible-light-induced oxidative dehydrogenative process is disclosed, which uses an organoboron compound as the photocatalyst and molecular oxygen as the sole oxidant.Viathis approach, an array of N-heterocycles have been accessed under metal-free mild conditions, in good to excellent yields.
Method for preparing N - heterocyclic ring through visible light mediated dehydrogenation
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Paragraph 0068-0073, (2021/10/02)
The invention discloses a method for preparing N - heterocyclic rings through visible light mediated dehydrogenation, and the reaction can be carried out under the conditions of room temperature and visible light without heating. The novel tetra-coordination N-N - diaryl chelating borate compound serves as a photocatalyst, so that the use of a noble metal photocatalyst is avoided, precious metal residue in the reaction product can be reduced as much as possible, and the method is more suitable for synthesizing bioactive molecules.
Mixed crystalline phases and catalytic performance of OMS-2 based nanocomposites for one-pot synthesis of quinazolines with O2 as an oxidant
Yao, Nan,Bi, Xiuru,Zhang, Liping,Tao, Luyao,Zhao, Peiqing,Meng, Xu,Liu, Xiang
, (2021/03/03)
In this work, a series of sodium phosphotungstate modified manganese oxide octahedral molecular sieve (OMS-2) catalysts ([PW]-OMS-2) were developed, and their catalytic activities were investigated by one-pot synthesis of quinazolines from benzyl alcohol and 2-aminobenzylamine with O2 as green oxidant in dimethyl carbonate (DMC). TEM, XRD and EDS confirmed that sodium phosphotungstate decomposed into phosphotungstic acid and sodium tungstate in the doping process. Meanwhile, phosphotungstic acid attached and located at the surface of OMS-2 and W ions were successfully doped into the OMS-2 framework. For comparison, phosphotungstic acid/OMS-2 was prepared by simple wet impregnation method. The [PW]-OMS-2 is the most highly selective and effective over than phosphotungstic acid/OMS-2 and OMS-2 itself in the one-pot synthesis of quinazolines. It may be due to the synergetic effect of phosphotungstic acid and OMS-2, and successfully doping W into OMS-2 frameworks. Hence, this work provides a new environmentally-friendly and heterogeneous OMS-2 based nanocomposites and it may be put into practice to synthesize heterocyclic compounds.
Palladium(ii): N, N, O -pincer type complex-mediated dehydrogenative coupling of alcohols to quinazolines
Anandaraj, Pennamuthiriyan,Kumaradhas, Poomani,Ramesh, Rengan
, p. 16572 - 16580 (2021/10/01)
A new palladium(ii) N,N,O-pincer type complex-promoted one-pot cascade synthesis of quinazolines through the dehydrogenative coupling of easily available alcohols and 2-aminobenzylamine is reported. A distinct set of Pd(ii) complexes (1-2) was synthesized
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.
K2S2O8activation by glucose at room temperature for the synthesis and functionalization of heterocycles in water
Hunjan, Mandeep Kaur,Laha, Joydev K.
supporting information, p. 8437 - 8440 (2021/09/02)
While persulfate activation at room temperature using glucose has primarily been focused on kinetic studies of the sulfate radical anion, the utilization of this protocol in organic synthesis is rarely demonstrated. We reinvestigated selected K2S2O8-mediated known organic reactions that invariably require higher temperatures and an organic solvent. A diverse, mild functionalization and synthesis of heterocycles using the inexpensive oxidant K2S2O8 in water at room temperature is reported, demonstrating the sustainability and broad scope of the method. Unlike traditional methods used for persulfate activation, the current method uses naturally abundant glucose as a K2S2O8 activator, avoiding the use of higher temperature, UV light, transition metals or bases.
