26059-85-8

Upstream product

• 3437-95-4 2-Iodothiophene 
• 201230-82-2 carbon monoxide 
• 28144-70-9 anthranilic acid amide 
• 27757-85-3 2-Aminomethylthiophene 
• 21403-24-7 N-(thiophen-2-ylmethyl)acetamide 
• 527-72-0 2-thiophenylcarboxylic acid 
• 1918-77-0 Thiophene-2-acetic acid 
• 1003-09-4 2-bromothiophene 
• 636-72-6 2-thiophenemethanol 
• 98-03-3 thiophene-2-carbaldehyde 

Downstream Products

• 1264533-94-9 2-(thiophen-2-yl)-4-(1-tosylpiperidin-4-yl)quinazoline 
• 59455-95-7 4-chloro-2-(thien-2-yl)quinazoline 

Relevant academic research and scientific papers

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.

Novel phosphorescent iridium(III) complexes containing 2-thienyl quinazoline ligands: Synthesis, photophysical properties and theoretical calculations

The easy tailoring of organic ligands of iridium(iii) complexes provides a facile way to tune their opto-electronic properties for applications in high efficiency phosphorescent light emitting diodes. Herein, a series of yellow and red emitting phosphorescent iridium complexes based on 2-thienyl quinazoline derivatives are successfully synthesized and systematically characterized with various opto-electronic properties. The X-ray crystal structures demonstrate that the iridium centers in the complexes with bulky substituents on the 4-position of quinazolyl rings prefer to chelate with the N atoms in the 1-position of quinazolyl rings. Both experiment and theoretical studies indicate that the steric hindrance along with the electron-donating effect of substituents on the C^N ligands enhances the emission quantum yields, accompanied by significant emission shifts. Two yellow phosphorescent iridium complexes (Ir2 and Ir3) are successfully designed and exhibit moderate emission efficiencies, through the incorporation of bulky ligands with strong electron-donating abilities (piperidine for Ir2 and 2,6-dimethyl-phenoxy for Ir3, respectively). The synergistic effect of electron structure and hindrance of ligand is believed to be a promising strategy for tuning the opto-electronic properties of iridium complexes.

N^N^O hydrazone capped pincer type palladium complex catalysed construction of quinazolinones from alcohols

New Pincer type Pd(II) complex [Pd(NNO)(PPh3)] (1) prompted synthesis of quinazolinones via dehydrogenative coupling of readily accessible alcohols, and o-aminobenzamide is described. A diverse range of quinazolinones has been synthesized efficiently with good to excellent yields employing low catalyst loading (0.5 mol%) under the aerobic condition without any additives/oxidants. A plausible mechanism for the construction of quinazolinones has been proposed via cyclic aminal intermediate. Large-scale synthesis attests to the productiveness of the current strategy.

Aerobic primary and secondary amine oxidation cascade by a copper amine oxidase inspired catalyst

Herein, we report a bioinspired catalytic system for the one-pot cascade oxidation of a native primary amine and anin situgenerated non-native secondary amine. The catalyst consists of ano-quinone cofactor phd (1,10-phenanthroline-5,6-dione) and a copper ion and operates under ambient air conditions. Quinazolin-4(3H)-ones, which are common pharmacophores present in numerous pharmaceuticals and bioactive compounds, were synthesized in high yields. A detailed kinetic and mechanistic study elucidates the role of the catalyst in the multi-step oxidative cascade reaction.

Visible light induced tandem reactions: An efficient one pot strategy for constructing quinazolinones using in-situ formed aldehydes under photocatalyst-free and room-temperature conditions

A facile tandem route has been developed for constructing quinazolinones from various aminobenzamides and in-situ generated aldehydes. Visible light was found to play a dual role: first oxidizes the alcohol to the aldehyde and then facilitates its cyclization with o-substituted aniline. Furthermore, alcohols are perfect alternatives to aldehydes because they are greener, more available, more economical, more stable, and less toxic than aldehydes. The first reaction step continuously provides material for the second step, which effectively reduces loss through volatilization, oxidation, and polymerization of the aldehyde, while avoiding its toxicity. A variety of quinazolinones can be prepared in the presence of visible light without any additional photocatalyst. The developed synthesis protocol proceeds with the merits of mild conditions, broad substrate scope, operational simplicity, and high atom efficiency, with an eco-energy source under metal-free, photocatalyst-free, and ambient conditions.

Electrochemical synthesis of quinazolinone: via I2-catalyzed tandem oxidation in aqueous solution

The development of protocols for synthesizing quinazolinones using biocompatible catalysts in aqueous medium will help to resolve the difficulties of using green and sustainable chemistry for their synthesis. Herein, using I2 in coordination with electrochemical synthesis induced a C-H oxidation reaction which is reported when using water as the environmentally friendly solvent to access a broad range of quinazolinones at room temperature. The reaction mechanism strongly showed that I2 cooperates electrochemically promoted the oxidation of alcohols, then effectively cyclizing amides to various quinazolinones.

Iron catalyzed metal-ligand cooperative approaches towards sustainable synthesis of quinolines and quinazolin-4(3H)-ones

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.

Metal-free catalyst for the visible-light-induced photocatalytic synthesis of quinazolinones

In the present work, we have developed a novel and environmentally friendly method for the synthesis of quinazolinones using fluorescein as a photocatalyst via a condensation reaction of o-aminobenzamides and aldehydes under visible light irradiation. In this protocol, neither toxic oxidants nor transition-metal catalysts were needed, and a series of quinazolinones could be obtained in high efficiencies. In addition, this reaction can be extended to gram levels and has a large potential of wide application in future industrialization.

Catalyst-free synthesis of quinazolinones by oxidative cyclization under visible light in the absence of additives

A general metal-free oxidative cyclization route was developed to synthesize quinazolinones under visible light. A series of substituted 2-aminobenzamides were reacted with aldehydes or ketones to produce the desired quinazolinones in good yields. Most importantly, the reaction did not require excess oxidant or high temperatures.

Design, synthesis, characterization, enzymatic inhibition evaluations, and docking study of novel quinazolinone derivatives

In this study, novel quinazolinone derivatives 7a-n were synthesized and evaluated against metabolic enzymes including α-glycosidase, acetylcholinesterase, butyrylcholinesterase, human carbonic anhydrase I, and II. These compounds exhibited high inhibitory activities in comparison to used standard inhibitors with Ki values in the range of 19.28–135.88 nM for α-glycosidase (Ki value for standard inhibitor = 187.71 nM), 0.68–23.01 nM for acetylcholinesterase (Ki value for standard inhibitor = 53.31 nM), 1.01–29.56 nM for butyrylcholinesterase (Ki value for standard inhibitor = 58.16 nM), 10.25–126.05 nM for human carbonic anhydrase I (Ki value for standard inhibitor = 248.18 nM), and 13.46–178.35 nM for human carbonic anhydrase II (Ki value for standard inhibitor = 323.72). Furthermore, the most potent compounds against each enzyme were selected in order to evaluate interaction modes of these compounds in the active site of the target enzyme. Cytotoxicity assay of the title compounds 7a-n against cancer cell lines MCF-7 and LNCaP demonstrated that these compounds do not show significant cytotoxic effects.