18818-40-1Relevant academic research and scientific papers
N^N^O hydrazone capped pincer type palladium complex catalysed construction of quinazolinones from alcohols
Anandaraj, Pennamuthiriyan,Kamatchi, Thangavel Sathiya,Ramesh, Rengan
, (2022/01/11)
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.
Linear-Organic-Polymer-Supported Iridium Complex as a Recyclable Auto-Tandem Catalyst for the Synthesis of Quinazolinones via Selective Hydration/Acceptorless Dehydrogenative Coupling from o-Aminobenzonitriles
Hao, Shushu,Yang, Jiazhi,Liu, Peng,Xu, Jing,Yang, Chenchen,Li, Feng
supporting information, p. 2553 - 2558 (2021/04/13)
A linear-organic-polymer-supported iridium complex Cp*Ir@P4VP, which is designed and synthesized by the coordinative immobilization of [Cp*IrCl2]2 on poly(4-vinylpyridine), was proven to be an efficient heterogeneous autotandem catalyst for synthesizing quinazolinones via selective hydration/acceptorless dehydrogenative coupling from o-aminobenzonitriles. Furthermore, the synthesized catalyst was recycled five times without an obvious decrease in the catalytic activity.
Palladium-catalyzed one-pot synthesis of 2-substituted quinazolin-4(3H)-ones fromo-nitrobenzamide and alcohols
Wang, Ke,Chen, Hao,Dai, Xinyan,Huang, Xupeng,Feng, Zhiqiang
, p. 13119 - 13123 (2021/04/22)
Palladium-catalyzed 2-substituted quinazolin-4(3H)-one formation from readily availableo-nitrobenzamides and alcohols using hydrogen transfer is described. Various quinazolin-4(3H)-ones were obtained in good to high yields. The cascade reaction including
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.
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.
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
Xie, Zongbo,Lan, Jin,Zhu, Haibo,Lei, Gaoyi,Jiang, Guofang,Le, Zhanggao
supporting information, p. 1427 - 1431 (2020/11/02)
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.
Palladium(II) N^O Chelating Complexes Catalyzed One-Pot Approach for Synthesis of Quinazolin-4(3 H)-ones via Acceptorless Dehydrogenative Coupling of Benzyl Alcohols and 2-Aminobenzamide
Balaji, Sundarraman,Balamurugan, Gunasekaran,Ramesh, Rengan,Semeril, David
, p. 725 - 734 (2021/04/06)
A convenient protocol for the one-pot synthesis of quinazolin-4(3H)-ones using palladium(II) complexes via dehydrogenative coupling of readily available benzyl alcohols and 2-aminobenzamide has been described. New structurally related Pd(II) N^O chelating complexes of general configuration [Pd(L)Cl(PPh3)] (where L = dimethylamino benzoylhydrazone ligands) have been designed and synthesized. The formation of the complexes has been recognized by analytical and spectral methods (FT-IR, NMR, HR-MS). The presence of a square-planar geometry around the palladium(II) ion was confirmed by single crystal X-ray diffraction study. A wide range of substituted quinazolinones have been successfully achieved from a diverse range of benzyl alcohols in good to excellent yields using 1.0 mol % of catalyst loading under aerobic conditions. Furthermore, control experiments reveal that the dehydrogenative coupling reaction involves initially the formation of an aldehyde intermediate and subsequent formation of a cyclic aminal intermediate.
Ruthenium(II)-catalyzed C?C/C?N coupling of 2-arylquinazolinones with vinylene carbonate: Access to fused quinazolinones
Wang, Zhao-Hui,Wang, He,Wang, Hua,Li, Lei,Zhou, Ming-Dong
supporting information, p. 995 - 999 (2021/03/03)
In this work, ruthenium(II)-catalyzed C?C/C?N annulation of 2-arylquinazolinones with vinylene carbonate is reported to synthesize fused quinazolinones. This catalytic system tolerates a wide range of substrates with excellent functional-group compatibility. In this transformation, the vinylene carbonate acts as an ethynol surrogate without any external oxidant involved. Furthermore, preliminary mechanistic studies were conducted, and a plausible catalytic cycle was also proposed.
α-Keto Acids as Triggers and Partners for the Synthesis of Quinazolinones, Quinoxalinones, Benzooxazinones, and Benzothiazoles in Water
Huang, Jian,Chen, Wei,Liang, Jiazhi,Yang, Qin,Fan, Yan,Chen, Mu-Wang,Peng, Yiyuan
, p. 14866 - 14882 (2021/10/25)
A general and efficient method for the synthesis of quinazolinones, quinoxalinones, benzooxazinones, and benzothiazoles from the reactions of α-keto acids with 2-aminobenzamides, benzene-1,2-diamines, 2-aminophenols, and 2-aminobenzenethiols, respectively, is described. The reactions were conducted under catalyst-free conditions, using water as the sole solvent with no additive required, and successfully applied to the synthesis of sildenafil. More importantly, these reactions can be conducted on a mass scale, and the products can be easily purified through filtration and washing with ethanol (or crystallized).
Aerobic primary and secondary amine oxidation cascade by a copper amine oxidase inspired catalyst
Thorve, Pradip Ramdas,Maji, Biplab
, p. 1116 - 1124 (2021/02/26)
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.
