1078-28-0Relevant articles and documents
Aerobic oxidative dehydrogenation of N-heterocycles catalyzed by cobalt porphyrin
Zhou, Weiyou,Chen, Dongwei,Sun, Fu'an,Qian, Junfeng,He, Mingyang,Chen, Qun
, p. 949 - 953 (2018)
An efficient catalytic procedure has been developed for the aerobic oxidative dehydrogenation of N-heterocycles by cobalt porphyrin in the absence of any additives. The catalytic system could tolerate various 1,2,3,4-tetrahydroquinoline derivatives and some other N-heterocycles. The corresponding N-heteroaromatics could be obtained in 59–86% yields. The mechanism investigation suggested that the aerobic oxidative dehydrogenation might proceed with imine intermediate through radical paths.
Continuous Flow Doebner-Miller Reaction and Isolation Using Continuous Stirred Tank Reactors
Yadav, Maruti B.,Kulkarni, Sourabh,Joshi, Ramesh A.,Kulkarni, Amol A.
, p. 1621 - 1625 (2016)
Continuous flow Doebner-Miller synthesis of different quinaldines from respective anilines is demonstrated using sulfuric acid as a homogeneous catalyst. The extent of reaction was monitored for various parameters, namely, temperature, residence time, mole ratio of sulfuric acid to substrate, mole ratio of crotonaldehyde to substrate, and so forth. Continuous stirred reactors in series were used as a preferred configuration for this rection that generates byproduct in the form of sticky solid material. The approach has been extended for six different anilines, and the results are compared with batch reactions. Continuous stirred reactors in series with distributed dosing of crotonaldehyde facilitated a continuous flow reaction with lower byproduct formation, increased yields, and continuous workup and is a scalable approach.
Synthesis and structure elucidation of allyl Pd(II) complexes of NHC ligands derived from substituted imidazo[1,5-a]quinolin-1(2H)-ylidene
Lyapchev, Rumen,Petrov, Petar,Dangalov, Miroslav,Vassilev, Nikolay G.
, p. 194 - 209 (2017)
Nine Pd(II) complexes involving N-heterocyclic carbenes (NHCs) derived from 2-substituted and 2- and 7-substituted imidazo[1,5-a]quinolin-1(2H)-ylidene with auxiliary allylic ligands were synthesized and characterized. The structure and configuration of the complexes were elucidated on the basis of combination of dynamic NMR and DFT studies. Conformational studies in respect of hindered rotation around Pd-C bond and η3-η1-η3 pseudo allyl rotation were performed. The results from dynamic NMR and DFT studies confirmed the mechanism of selective η3-η1-η3 isomerization, whose energy barriers are affected by steric hindrance of substituents at nitrogen atom. Energy barriers of isomerization (16.7–18.8 kcal/mol) are slightly influenced by the electronic nature of substituents at seventh position in imidazo[1,5-a]quinolin-1(2H)-ylidene moiety. The results from DFT calculations were in good agreement with the experimental energy barriers.
A highly selective and easy-to-synthesize Zn(II) fluorescent probe based on 6-methoxyquinolin
Zhao, Hua Yang,Li, Yi Ming,Gong, Tian Jun,Guo, Qing Xiang
, p. 1013 - 1016 (2011)
A novel fluorescent Zn2+ probe based on 6-methoxyquinolin was synthesized in four steps from inexpensive starting materials. It exhibits very strong fluorescence responses and has a remarkably high selectivity to Zn 2+ than other physiological relevant metal ions. This new compound could be used as low-priced yet high-quality Zn2+ probe.
A water soluble ratiometric fluorescent probe for targeting SO2in mitochondria based on conjugated biquinolines
Yang, Jialu,Yin, Caixia,Ma, Kaiqing,Yue, Yongkang,Huo, Fangjun
, p. 20235 - 20240 (2020)
Despite the unprecedented development of SO2 fluorescent probes in the past five years, the water-solubility of these probes is still an important factor related to their practical application. In previous work, we have studied SO2 detection by coupling quinoline and coumarin. Although the water solubility of the probe was improved, SO2 detection in a 100% aqueous medium was not fully achieved. Therefore, based on the previous system, we conjugated two quinolines to realize a 100% water-soluble sulfur dioxide fluorescent probe. The Probe showed a large Stokes shift (170 nm). Besides, the Probe could respond to SO2 within 1.5 min with high selectivity and sensitivity (LOD = 0.29 μM). In addition, fluorescence co-localization studies suggested that the Probe could be used for monitoring SO2 in the mitochondria of HeLa cells and living mice. It is believed that such an excellent probe will have a wide application prospect in the future. This journal is
High throughput one pot synthesis of 2-methylquinolines
Chandrashekarappa, Kiran Kumar H.,Mahadevan, Kittappa M.,Manjappa, Kiran B.
, p. 1368 - 1370 (2013)
Various 2-methylquinolines have been successfully synthesized by using anilines and ethyl vinyl ether in 1:3 mole ratios in the presence of acetic acid. Stirring at rt for 3-4 h followed by reflux for 3.5-4 h resulted in the corresponding 2-methylquinolines in good yield. Copyright
Miceller-mediated phosphomolybdic acid: Highly effective reusable catalyst for synthesis of quinoline and its derivatives
Chaskar, Atul,Padalkar, Vikas,Phatangare, Kiran,Langi, Bhushan,Shah, Chetan
, p. 2336 - 2340 (2010)
A simple, efficient, and ecofriendly procedure has been developed for the synthesis of quinoline and its derivatives in a one-pot reaction of aniline with crotonaldehyde or methyl vinyl ketone using phosphomolybdic acid as solid acid catalyst in miceller media. The catalyst was easily recycled and reused. Copyrigh
Magnetically separable palladium-graphene nanocomposite as heterogeneous catalyst for the synthesis of 2-alkylquinolines via one pot reaction of anilines with alkenyl ethers
Verma, Sanny,Verma, Deepak,Jain, Suman L.
, p. 2406 - 2409 (2014)
The present Letter describes the use of magnetically separable palladium-graphene nanocomposite, a complete magnetically separable catalyst for the synthesis of 2-alkyl quinolines via reaction of anilines with alkenyl ethers. Because of the uniform decoration of the Pd nanoparticles on support, the catalyst exhibited higher catalytic efficiency and it remains unaltered even after six repeated cycles.
The Rhodium Complex-catalyzed Synthesis of Quinolines from Aminoarenes and Aliphatic Aldehydes
Watanabe, Yoshihisa,Shim, Sang Chul,Mitsudo, Take-aki
, p. 3460 - 3465 (1981)
A variety of aminoarenes react with aliphatic aldehydes in the presence of a catalytic amount of a rhodium complex and an excess amount of the corresponding nitroarenes at 180 deg C to give 2-alkyl- and 2,3-dialkyl-substituted quinolines in excellent yields.Among the rhodium complexes examined, 2 exhibits the highest activity as a catalyst.Thus, 2-methyl-, 2-ethyl-3-methyl-, 2-propyl-3-ethyl-, 2-butyl-3-propylquinoline derivatives are readily obtained from aminoarenes and ethanal, propanal, butanal, and pentanal respectively.
Quinoline Synthesis by the Reaction of Anilines with 1,2-diols Catalyzed by Iron Compounds
Khusnutdinov, Ravil,Bayguzina, Alfiya,Aminov, Rishat,Dzhemilev, Usein
, p. 1022 - 1029 (2016)
The synthesis of quinoline derivatives by cyclocondensation of anilines with 1,2-ethanediol, 1,2-propanediol, and 1,2-butanediol in the presence of iron-containing catalysts was performed for the first time.
Tris(pentafluorophenyl)borane-Catalyzed Acceptorless Dehydrogenation of N-Heterocycles
Kojima, Masahiro,Kanai, Motomu
, p. 12224 - 12227 (2016)
Catalytic acceptorless dehydrogenation is an environmentally benign way to desaturate organic compounds. This process is traditionally accomplished with transition-metal-based catalysts. Herein, a borane-catalyzed, metal-free acceptorless dehydrogenation of saturated N-heterocycles is disclosed. Tris(pentafluorophenyl)borane was identified as a versatile catalyst, which afforded several synthetically important N-heteroarenes in up to quantitative yield. Specifically, the present metal-free catalytic system exhibited a uniquely high tolerance toward sulfur functionalities, and demonstrated superior reactivity in the synthesis of benzothiazoles compared to conventional metal-catalyzed systems. This protocol can thus be regarded as the first example of metal-free acceptorless dehydrogenation in synthetic organic chemistry.
Synthesis of quinaldines and lepidines by a Doebner-Miller reaction under thermal and microwave irradiation conditions using phosphotungstic acid
Sivaprasad, Ganesabaskaran,Rajesh, Rengasamy,Perumal, Paramasivan T.
, p. 1783 - 1785 (2006)
A simple and efficient method has been developed for the synthesis of quinaldines and lepidines by a one-pot reaction of anilines with crotonaldehyde or methyl vinyl ketone using phosphotungstic acid, a Keggins-type heteropoly acid, under both thermal and microwave irradiation conditions.
NOVEL COMPOUNDS USEFUL AS NEAR-INFRARED FLUORESCENT PROBES SELECTIVELY BINDING TO TAU AGGREGATES AND METHOD OF PREPARING THE SAME
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Paragraph 0161-0163, (2021/08/20)
Disclosed are a compound with near-infrared fluorescence that selectively binds to tau aggregates, a method for preparing the same, a tau-targeting near-infrared fluorescent probe including the compound, a composition for detecting a tau fiber protein containing the near-infrared fluorescent probe as an active ingredient, and the use of the composition for the diagnosis of tauopathy. In particular, the compound does not bind to an amyloid beta protein and has high selectivity to a tau aggregate, specifically reported as an etiology of the initial state of tauopathy, thus being useful as a near-infrared fluorescent detector for detecting a tau fiber protein for early diagnosis of a tauopathy including Alzheimer's disease.
ZnMe2-Mediated, Direct Alkylation of Electron-Deficient N-Heteroarenes with 1,1-Diborylalkanes: Scope and Mechanism
Jo, Woohyun,Baek, Seung-Yeol,Hwang, Chiwon,Heo, Joon,Baik, Mu-Hyun,Cho, Seung Hwan
supporting information, p. 13235 - 13245 (2020/09/01)
The regioselective, direct alkylation of electron-deficient N-heteroarenes is, in principle, a powerful and efficient way of accessing alkylated N-heteroarenes that are important core structures of many biologically active compounds and pharmaceutical agents. Herein, we report a ZnMe2-promoted, direct C2- or C4-selective primary and secondary alkylation of pyridines and quinolines using 1,1-diborylalkanes as alkylation sources. While substituted pyridines and quinolines exclusively afford C2-alkylated products, simple pyridine delivers C4-alkylated pyridine with excellent regioselectivity. The reaction scope is remarkably broad, and a range of C2- or C4-alkylated electron-deficient N-heteroarenes are obtained in good yields. Experimental and computational mechanistic studies imply that ZnMe2 serves not only as an activator of 1,1-diborylalkanes to generate (α-borylalkyl)methylalkoxy zincate, which acts as a Lewis acid to bind to the nitrogen atom of the heterocycles and controls the regioselectivity, but also as an oxidant for rearomatizing the dihydro-N-heteroarene intermediates to release the product.
