1514933-73-3

Upstream product

• 2142-69-0 2-bromophenyl methyl ketone 
• 4001-73-4 2-Bromobenzamide 
• 3959-05-5 2-bromobenzylamine 
• 26767-16-8 2-(2-bromophenyl)-2-oxoacetic acid 
• 4403-69-4 2-amino-1-benzylamine 
• 5344-90-1 2-Aminobenzyl alcohol 
• 18982-54-2 o-bromobenzyl alcohol 
• 6630-33-7 ortho-bromobenzaldehyde 
• 3433-80-5 1-Bromo-2-bromomethyl-benzene 
• 1514933-77-7 2-(2-bromophenyl)-1,2,3,4-tetrahydroquinazoline 

Relevant academic research and scientific papers

Copper (II) complex supported on the surface of magnetic nanoparticles modified with S-benzylisothiourea (Fe3O4@SiO2-SMTU-Cu): A new and efficient nanomagnetic catalyst for the synthesis of quinazolines and amides

A novel magnetically recoverable copper catalyst was successfully fabricated through the immobilization of Cu(NO3)2 on the surface of silica-coated magnetic Fe3O4 nanoparticles (Fe3O4@SiO2) functionalized with S-benzylisothiourea ligand. The Fe3O4@SiO2-SMTU-Cu nanocomposite was fully characterized by FT-IR spectroscopy, SEM, EDX, TGA, XRD, VSM, ASS and ICP-OES techniques. The Fe3O4@SiO2-SMTU-Cu nanocomposite exhibited high catalytic activity in the synthesis of biologically active quinazolines and amides. According to our research on the literature, this is the first report in the use of magnetic copper nanocatalyst for the synthesis of quinazolines. In this paper, we also presented tentative mechanisms for the synthesis of quinazolines and amides in the presence of catalytic amount of Fe3O4@SiO2-SMTU-Cu nanocomposite. This method gives notable advantages such as easy separation of the catalyst by external magnetic field; excellent yields, short reaction times, nontoxic metal catalyst, and simplicity of operation make this method a facile tool for the synthesis of quinazolines and amides.

Zinc Stabilized Azo-anion Radical in Dehydrogenative Synthesis of N-Heterocycles. An Exclusively Ligand Centered Redox Controlled Approach

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.

Possible competitive modes of decarboxylation in the annulation reactions ofortho-substituted anilines and arylglyoxylates

Annulation reactions ofortho-substituted anilines and arylglyoxylates in the presence of K2S2O8at 80 °C under metal-free neutral conditions have been investigated, which extended a platform for the tandem synthesis of nitrogen heterocycles. While arylglyoxylic acids are known to undergo decarboxylation to form an acyl radical in the presence of K2S2O8and used in the Minisci acylation of electron-deficient (hetero)aromatics, their reactions with electron-richortho-substituted anilines to form nitrogen heterocycles have recently been studied. Depending upon the experimental conditions used in the reactions, the mechanism of the formation of heterocycles involving reactions of an acyl radical or aryl iminocarboxylic acids has been postulated. Given the subtle understanding of the mechanisms of annulation reactions of 2-substituted anilines and arylglyoxylates in the presence of K2S2O8, an extensive mechanistic investigation was undertaken. In the current study, the various mechanistic pathways including the generation of acyl, imidoyl, aminal, and N,O-hemiketal radicals have been postulated based on different possible decarboxylation modes. Some of the proposed intermediates are supported based on the available analytical data. The protocol uses a single, inexpensive reagent K2S2O8, which offers not only transition-metal-free conditions but also serves as the reagent for the key decarboxylation step. Taken together, this study complements the current development of the annulation reactions of 2-substituted anilines and arylglyoxylates in terms of synthesis and mechanistic understanding.

Manganese(I)-Catalyzed Sustainable Synthesis of Quinoxaline and Quinazoline Derivatives with the Liberation of Dihydrogen

Direct synthesis of N-heterocycles via the acceptorless dehydrogenative coupling is very challenging and scarcely reported under 3d transition-metal catalysis. Here, we have developed an efficient Mn(I)-catalyzed sustainable synthesis of various quinoxalines from 1,2-diaminobenzenes and 1,2-diols via the acceptorless dehydrogenative coupling reaction. Further, this strategy was successfully applied for the unprecedented synthesis of quinazolines by the reaction of 2-aminobenzyl alcohol with primary amides. The present protocol provides an atom-economical and sustainable route for the synthesis of various quinoxaline and quinazoline derivatives by employing an earth-abundant manganese salt and simple phosphine-free NNN-tridentate ligand.

Divergent Synthesis of Quinazolines Using Organocatalytic Domino Strategies under Aerobic Conditions

An easy and efficient organocatalytic approach to the synthesis of 2-substituted quinazolines is described based on the reaction between 2-aminobenzylamines and aldehydes or alcohols or amines. Three organocatalytic platforms were investigated, using 3-nitropyridine, pyridine N-oxide, and vitamin B3. Having established the new catalytic systems, the tandem transformations of 2-aminobenzylamines to give substituted quinazolines were achieved in excellent yields and with a broad substrate scope, with no formation of toxic side-products. The investigated conditions are not restricted to the use of aldehydes; the protocol also works well with alcohols or amines as substrates. These are oxidized in situ to the corresponding aldehydes to achieve the successful transformation. A mechanistic proposal has been drawn up based on control experiments. We found that under aerobic conditions, catalytic amounts of H2O2 can be generated; this plays a key role in the efficacy of the described approach. The green chemistry metrics of the developed method are also presented. The E factor of 8.18 mg/1 mg demonstrates that the reported method is an excellent complement to previous protocols.

ABNO-Catalyzed Aerobic Oxidative Synthesis of 2-Substituted 4H-3,1-Benzoxazines and Quinazolines

A new transition-metal-free 9-azabicyclo[3.3.1]nonan-N-oxyl (ABNO) catalyzed aerobic oxidative synthesis of 2-substituted 4H-3,1-benzoxazines and quinazolines has been developed through cascade reaction of aldehydes with 2-aminobenzyl alcohols and 2-amino

Bioinspired aerobic oxidation of secondary amines and nitrogen heterocycles with a bifunctional quinone catalyst

Copper amine oxidases are a family of enzymes with quinone cofactors that oxidize primary amines to aldehydes. The native mechanism proceeds via an iminoquinone intermediate that promotes high selectivity for reactions with primary amines, thereby constraining the scope of potential biomimetic synthetic applications. Here we report a novel bioinspired quinone catalyst system consisting of 1,10-phenanthroline-5,6-dione/ZnI2 that bypasses these constraints via an abiological pathway involving a hemiaminal intermediate. Efficient aerobic dehydrogenation of non-native secondary amine substrates, including pharmaceutically relevant nitrogen heterocycles, is demonstrated. The ZnI2 cocatalyst activates the quinone toward amine oxidation and provides a source of iodide, which plays an important redox-mediator role to promote aerobic catalytic turnover. These findings provide a valuable foundation for broader development of aerobic oxidation reactions employing quinone-based catalysts.

Synthesis of quinazolines and tetrahydroquinazolines: Copper-catalyzed tandem reactions of 2-bromobenzyl bromides with aldehydes and aqueous ammonia or amines

An efficient synthesis of diversely substituted quinazolines and 1,2,3,4-tetrahydroquinazolines through copper-catalyzed tandem reactions of the readily available 2-bromobenzyl bromides, aldehydes, and aqueous ammonia or amines has been developed. By using ammonia and simple aliphatic amines as the nitrogen source, the present method provides a versatile and practical protocol for the synthesis of quinazolines and 1,2,3,4-tetrahydroquinazolines. Copper on the beat: An efficient, simple and economical synthesis of diversely substituted quinazolines and 1,2,3,4-tetrahydroquinazolines has been developed through copper-catalyzed tandem reactions of the readily available 2-bromobenzyl bromides, aldehydes, and aqueous ammonia or simple aliphatic amines. Copyright