- Aerobic oxidative dehydrogenation of N-heterocycles catalyzed by cobalt porphyrin
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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.
- Zhou, Weiyou,Chen, Dongwei,Sun, Fu'an,Qian, Junfeng,He, Mingyang,Chen, Qun
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- Catalytic Asymmetric Cascade Using Spiro-Pyrrolidine Organocatalyst: Efficient Construction of Hydrophenanthridine Derivatives
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A newly developed SPD (spiro-pyrrolidine) organocatalyst has been demonstrated to enable an asymmetric aza-Michael/Michael/aldol cyclization cascade, in which two six-membered rings (B/C) and three stereocenters have been constructed in a catalytic one-step process. It is so far the most efficient method for construction of hydrophenanthridine derivatives featuring high enantioselectivity. The trans- or cis-fused B/C-rings can be selectively assembled in a substrate-controlled manner. Moreover, this cascade could magnify to gram scale without loss of enanioselectivity.
- Tian, Jin-Miao,Yuan, Yong-Hai,Xie, Yu-Yang,Zhang, Shu-Yu,Ma, Wen-Qiang,Zhang, Fu-Min,Wang, Shao-Hua,Zhang, Xiao-Ming,Tu, Yong-Qiang
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- Continuous Flow Doebner-Miller Reaction and Isolation Using Continuous Stirred Tank Reactors
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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.
- Yadav, Maruti B.,Kulkarni, Sourabh,Joshi, Ramesh A.,Kulkarni, Amol A.
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- Discovery of fused heterocyclic carboxamide derivatives as novel α7-nAChR agonists: Synthesis, preliminary SAR and biological evaluation
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The α7 nicotinic acetylcholine receptor (α7 nAChR) has emerged as a promising therapeutic target for schizophrenia. In our previous work, a novel series of α7-nAChR agonists bearing scaffold of indolizine were discovered. To explore the effect of aromaticity on the activity and find more active agents, herein, fused heterocyclic carboxamide derivatives were designed and synthesized in this study. Based on the evaluation by two-electrode voltage clamp in Xenopus oocytes, 27 of the synthesized compounds showed obvious agonism of α7 nAChR. Particularly, compounds 10a and 10e showed significantly higher Emax than EVP-6124. The result illustrated the importance of aromaticity to the activity of agonism. Compound 10a, which showed EC50 of 1.88 μM and Emax of 72.4%, was further characterized comprehensively, including co-application with type II positive allosteric modulator PNU-120596, selectivity with other closely related ligand-gated ion channel, etc. The results showed that 10a showed moderate selectivity over other subtypes such as α4β2 and α3β4 nAChR. 10a evoked α7-like currents that were inhibited by MLA and enhanced in the presence of the α7 PAM PNU-120596. The analysis of binding mode and understanding of structure-activity relationship provided insights to develop more potent novel α7-nAChR agonists.
- Xue, Yu,He, Xiaomeng,Yang, Taoyi,Wang, Yuxi,Liu, Zhenming,Zhang, Guisen,Wang, Yanxing,Wang, Kewei,Zhang, Liangren,Zhang, Lihe
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- Synthesis and structure elucidation of allyl Pd(II) complexes of NHC ligands derived from substituted imidazo[1,5-a]quinolin-1(2H)-ylidene
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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.
- Lyapchev, Rumen,Petrov, Petar,Dangalov, Miroslav,Vassilev, Nikolay G.
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- Synthesis of 2,3-disubstituted quinolines from in situ generated imines and its enamine tautomer under radical cation induced conditions
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A tandem cyclization/aromatization of anilines and aldehydes was achieved under catalytic radical cation salt induced conditions, producing a series of 2,3-disubstituted quinolines in good yields. In this reaction, the in situ generated imine tautomerizes to enamine, which acts as a dienophile to participate in the tandem cyclization, and further elimination of the anilino group triggers the aromatization of tetrahydroquinolines, avoiding harsh conditions.
- Jia, Xiaodong,Peng, Fangfang,Qing, Chang,Huo, Congde,Wang, Yaxin,Wang, Xicun
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- A highly selective and easy-to-synthesize Zn(II) fluorescent probe based on 6-methoxyquinolin
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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.
- Zhao, Hua Yang,Li, Yi Ming,Gong, Tian Jun,Guo, Qing Xiang
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- Deracemization of Phenyl-Substituted 2-Methyl-1,2,3,4-Tetrahydroquinolines by a Recombinant Monoamine Oxidase from Pseudomonas monteilii ZMU-T01
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A monoamine oxidase (MAO5) from Pseudomonas monteilii ZMU-T01 was first heterologously expressed in Escherichia coli BL21(DE3) and then used as a biocatalyst for the deracemization of racemic 2-methyl-1,2,3,4-tetrahdroquinoline derivatives to yield the unreacted R enantiomer with up to >99 % ee. Sequence alignment revealed that MAO5 shared 14.7 % identity toward the well-studied monoamine oxidase (MAO-N).
- Deng, Guozhong,Wan, Nanwei,Qin, Lei,Cui, Baodong,An, Miao,Han, Wenyong,Chen, Yongzheng
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- A water soluble ratiometric fluorescent probe for targeting SO2in mitochondria based on conjugated biquinolines
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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
- Yang, Jialu,Yin, Caixia,Ma, Kaiqing,Yue, Yongkang,Huo, Fangjun
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- Limitations of the two-phase doebner-miller reaction for the synthesis of quinolines
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The Doebner-Miller synthesis of quinolines under modified biphasic conditions was investigated. Crotonaldehyde, reacted readily with aniline to produce 2-methylquinoline. However, cinnamaldehyde and other γ-substituted α,β-unsaturated aldehydes yielded complex mixtures with substituted anilines to provide only trace quantities of quinolines. The Doebner-Miller reaction under these conditions is only suitable for sterically accessible α,β-unsaturated aldehydes.
- Reynolds, Kristie A.,Young, David J.,Loughlin, Wendy A.
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- High throughput one pot synthesis of 2-methylquinolines
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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
- Chandrashekarappa, Kiran Kumar H.,Mahadevan, Kittappa M.,Manjappa, Kiran B.
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- Miceller-mediated phosphomolybdic acid: Highly effective reusable catalyst for synthesis of quinoline and its derivatives
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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
- Chaskar, Atul,Padalkar, Vikas,Phatangare, Kiran,Langi, Bhushan,Shah, Chetan
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- Synthesis of Quinolines via Intramolecular Cyclization of Benzylacetone Oxime Derivatives Catalyzed with Tetrabutylammonium Perrhenate(VII) and Trifluoromethanesulfonic Acid
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Intramolecular cyclization reaction on the nitrogen atom of benzylacetone oxime derivatives, which have electron donating group(s) on the phenyl group, proceeds by treatment with tetrabutylammonium perrhenate, trifluoromethanesulfonic acid, and 4-chloranil in refluxing 1,2-dichloroethane to afford quinoline derivatives in good yield.
- Kusama, Hiroyuki,Yamashita, Yuko,Narasaka, Koichi
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- Magnetically separable palladium-graphene nanocomposite as heterogeneous catalyst for the synthesis of 2-alkylquinolines via one pot reaction of anilines with alkenyl ethers
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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.
- Verma, Sanny,Verma, Deepak,Jain, Suman L.
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- Synthesis of Azaspirodienones via Intramolecular Cyclization of p-Hydroxybenzylacetone Oximes and Their Transformation into Quinolines
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Intramolecular cyclization reaction on the nitrogen atom of oximes of p-hydroxybenzylacetone derivatives proceeds by the treatment with tetrabutylammonium perrhenate and trifluoromethanesulfonic acid in refluxing 1,2-dichloroethane to afford azaspirodienones in good yield.The azaspirodienones are transformed into quinolines via dienone-phenol rearrangement.
- Kusama, Hiroyuki,Uchiyama, Katsuya,Yamashita, Yuko,Narasaka, Koichi
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- The Rhodium Complex-catalyzed Synthesis of Quinolines from Aminoarenes and Aliphatic Aldehydes
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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.
- Watanabe, Yoshihisa,Shim, Sang Chul,Mitsudo, Take-aki
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- Doebner-miller synthesis in a two-phase system: Practical preparation of quinolines
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Doebner-Miller cyclization was carried out in a two-phase solvent system. The method has shown to be advantageous to the yield and to the ease of the work-up process. (C) 2000 Elsevier Science Ltd.
- Matsugi,Tabusa,Minamikawa
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- Quinoline Synthesis by the Reaction of Anilines with 1,2-diols Catalyzed by Iron Compounds
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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.
- Khusnutdinov, Ravil,Bayguzina, Alfiya,Aminov, Rishat,Dzhemilev, Usein
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- Tris(pentafluorophenyl)borane-Catalyzed Acceptorless Dehydrogenation of N-Heterocycles
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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.
- Kojima, Masahiro,Kanai, Motomu
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- Synthesis of quinaldines and lepidines by a Doebner-Miller reaction under thermal and microwave irradiation conditions using phosphotungstic acid
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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.
- Sivaprasad, Ganesabaskaran,Rajesh, Rengasamy,Perumal, Paramasivan T.
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- Novel quinoline-based fluorescent bioimaging probe, KSNP117, for sentinel lymph node mapping
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Fluorescent imaging agents with biocompatibility and high sensitivity are urgently required for the accurate detection of sentinel lymph nodes (SLNs). Herein, we report the design of a novel quinoline-based fluorescent probe, designated KSNP117, which can be applied as a biomedical imaging agent in the sensitive and quantitative detection of SLNs. KSNP117 exerted no adverse effects on the proliferation of ovary and immune cells and also showed excellent serum stability with photo-brightening effects.In vivofluorescent imaging revealed the accumulation of KSNP117 in the SLNs of nude mice within 10 min post injection, withoutin vivotoxicity, which was consistent with the findings ofex vivoimaging. These results support the potential of KSNP117 as a promising lymphatic tracer for biomedical imaging applications.
- Cho, Sung Jin,Elbatrawy, Ahmed A.,Han, Ye Ri,Jeon, Hui-Jeon,Jeon, Yong Hyun,Kang, Kyung-Ku,Kim, Dong-Su,Kim, Kil Soo,Lee, Da Sol,Lee, Sang Bong,Lee, Sijoon,Nam, Ghilsoo,Sung, Soo-Eun
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supporting information
p. 4857 - 4862
(2021/07/01)
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- NOVEL COMPOUNDS USEFUL AS NEAR-INFRARED FLUORESCENT PROBES SELECTIVELY BINDING TO TAU AGGREGATES AND METHOD OF PREPARING THE SAME
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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.
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Paragraph 0161-0163
(2021/08/20)
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- Copper-Catalyzed Methoxylation of Aryl Bromides with 9-BBN-OMe
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A Cu-catalyzed cross-coupling reaction between aryl bromides and 9-BBN-OMe to provide aryl methyl ethers under mild conditions is reported. The oxalamide ligand BHMPO plays a key role in the transformation. Various functional groups on bromobenzenes are well tolerated, providing the desired anisole products in moderate to high yields.
- Li, Chen,Song, Zhi-Qiang,Wang, Dong-Hui,Wang, Jing-Ru
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supporting information
p. 8450 - 8454
(2021/11/17)
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- ZnMe2-Mediated, Direct Alkylation of Electron-Deficient N-Heteroarenes with 1,1-Diborylalkanes: Scope and Mechanism
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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.
- Jo, Woohyun,Baek, Seung-Yeol,Hwang, Chiwon,Heo, Joon,Baik, Mu-Hyun,Cho, Seung Hwan
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supporting information
p. 13235 - 13245
(2020/09/01)
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- A ortho position alkylation method of organic compound containg pyridine
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A process for introducing alkyl at ortho positions of organic compounds containing pyridine. The method is not affected by the kind of substituent bonded to the pyridine and can be alkylated with high positional selectivity and high yield at N-based ortho-position of pyridine without being affected by the kind of substituent introduced to pyridine ortho position (pyridine N-based) can be advantageously used for the preparation of a compound containing an alkyl-introduced pyridine structure.
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Paragraph 0108-0116
(2020/12/05)
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- C2-Selective C-H methylation of heterocyclic N-oxides with sulfonium ylides
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A redox-neutral C2-selective methylation of heterocyclic N-oxides with sulfonium ylides is described herein. This report presents unprecedented findings for the utility of sulfonium ylides as the methylation source of N-heterocycles beyond the Corey-Chaykovsky reaction. Intriguingly, pyrrolidine plays a significant role in minimizing the reductive C2-methylation process. This method is characterized by its mild conditions, simplicity, and excellent site selectivity. The applicability of the developed protocol is showcased by the late-stage methylation and sequential transformations of complex drug molecules.
- An, Won,Choi, Su Bin,Kim, Namhoon,Kwon, Na Yeon,Ghosh, Prithwish,Han, Sang Hoon,Mishra, Neeraj Kumar,Han, Sangil,Hong, Sungwoo,Kim, In Su
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supporting information
p. 9004 - 9009
(2020/11/30)
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- Method for synthesizing quinoline compounds in mode that oxidative dehydrogenation of tetrahydroquinoline compounds is synergistically catalyzed by visible light
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The invention relates to a method for synthesizing quinoline compounds in the mode that oxidative dehydrogenation of tetrahydroquinoline compounds is synergistically catalyzed by visible light. The method comprises the specific steps that in an air atmosphere, the multi-substituted tetrahydroquinoline compounds shown in the formula I, an organic photocatalyst DPZ and an auxiliary catalyst Cl4-NHPIare dissolved into an organic solvent, stirred and reacted for at least 2 hours at the temperature of 20-30 DEG C under the irradiation of the visible light, separation and purification are conducted, and the quinoline compounds shown in the formula II are obtained, wherein in the formula I and the formula II (the formulas are shown in the description), R is representative for any one of hydrogen, halogen, alkyl, phenyl and alkoxy, R1 is representative for any one of hydrogen, methyl, n-propyl and phenyl, alkyl is representative for methyl or ethyl or normal-butyl or benzyl, and aryl is representative for substituted phenyl. According to the method, reaction conditions are mild, the method is environmentally friendly, the usage amount of the catalyst is low, the product conversion ratio is high, the selectivity is good and no metal participates in a reaction.
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Paragraph 0008; 0011; 0017-0018
(2018/05/30)
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- Reductive C2-Alkylation of Pyridine and Quinoline N-Oxides Using Wittig Reagents
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The ability to alkylate pyridines and quinolines is important for their further development as pharmaceuticals and agrochemicals, and for other purposes. Herein we describe the unprecedented reductive alkylation of pyridine and quinoline N-oxides using Wittig reagents. A wide range of pyridine and quinoline N-oxides were converted into C2-alkylated pyridines and quinolines with excellent site selectivity and functional-group compatibility. Sequential C?H functionalization reactions of pyridine and quinoline N-oxides highlight the utility of the developed method. Detailed labeling experiments were performed to elucidate the mechanism of this process.
- Han, Sangil,Chakrasali, Prashant,Park, Jihye,Oh, Hyunjung,Kim, Saegun,Kim, Kyuneun,Pandey, Ashok Kumar,Han, Sang Hoon,Han, Soo Bong,Kim, In Su
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supporting information
p. 12737 - 12740
(2018/09/20)
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- Sequential Photoredox Catalysis for Cascade Aerobic Decarboxylative Povarov and Oxidative Dehydrogenation Reactions of N-Aryl α-Amino Acids
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A visible-light-driven sequential photoredox catalysis to allow N-aryl α-amino acids to experience efficient cascade aerobic decarboxylative Povarov and oxidative dehydrogenation (ODH) reactions is described. With a dicyanopyrazine-derived chromophore (DP
- Shao, Tianju,Yin, Yanli,Lee, Richmond,Zhao, Xiaowei,Chai, Guobi,Jiang, Zhiyong
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supporting information
p. 1754 - 1760
(2018/03/21)
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- A dual removable activating group enabled the Povarov reaction of N-arylalanine esters: synthesis of quinoline-4-carboxylate esters
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A dual removable activating group enabled Povarov reaction of N-arylalanine esters was reported. N-Arylalanine ester was utilized as the sole carbon source to generate N-arylimine and its tautomer, enamine, in situ by aerobic oxidation of sp3 C-H bonds, and then the consecutive reaction delivered the desired quinoline-4-carboxylate esters in high yields.
- Jia, Xiaodong,Lü, Shiwei,Yuan, Yu,Zhang, Xuewen,Zhang, Liang,Luo, Liangliang
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p. 2931 - 2937
(2017/04/10)
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- Acceptorless Dehydrogenation of N-Heterocycles by Merging Visible-Light Photoredox Catalysis and Cobalt Catalysis
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Herein, the first acceptorless dehydrogenation of tetrahydroquinolines (THQs), indolines, and other related N-heterocycles, by merging visible-light photoredox catalysis and cobalt catalysis at ambient temperature, is described. The potential applications to organic transformations and hydrogen-storage materials are demonstrated. Primary mechanistic investigations indicate that the catalytic cycle occurs predominantly by an oxidative quenching pathway.
- He, Ke-Han,Tan, Fang-Fang,Zhou, Chao-Zheng,Zhou, Gui-Jiang,Yang, Xiao-Long,Li, Yang
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supporting information
p. 3080 - 3084
(2017/03/14)
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- Method for catalyzing nitrogen heterocyclic ring compound for oxidative dehydrogenation with hydrotalcite-like material
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The invention relates to a method for catalyzing a nitrogen heterocyclic ring compound for oxidative dehydrogenation with a hydrotalcite-like material, and belongs to the application aspect of a hydrotalcite-like component. The hydrotalcite-like component can be expressed as: A-MxM-LDHs (A=OH or CO3; M=Ni, Co, Cu, Mg or Zn; M=Fe, Mn, Al; M/M=(2 to 4)). Under existence of the catalyst and without adding any additives, oxidative dehydrogenation reaction is performed on the heterocyclic ring compound under a mild condition to prepare a corresponding aromatic compound. According to the method provided by the invention, the hydrotalcite-like material is based on non-noble metal, can be synthesized largely, and can be recycled; the method has the advantages of being high in catalytic reaction efficiency, mild in reaction condition, low in cost, easy to industrialize and the like.
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Paragraph 0048; 0049; 0050; 0051; 0053
(2017/10/27)
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- Assembly of Diversely Substituted Quinolines via Aerobic Oxidative Aromatization from Simple Alcohols and Anilines
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An aerobic oxidative aromatization of simple aliphatic alcohols and anilines under the Pd(OAc)2/2,4,6-Collidine/Br?nsted acid catalytic system has been established, providing a direct approach for the preparation of diverse substituted quinoline derivatives in high yields with wide functional group tolerance. Practically, the protocol can be easily scaled up to gram-scale and was utilized in the concise formal synthesis of a promising herbicide candidate.
- Li, Jixing,Zhang, Jinlong,Yang, Huameng,Jiang, Gaoxi
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supporting information
p. 3284 - 3290
(2017/03/23)
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- Preparation method of quinoline derivative
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The invention provides a preparation method of a quinoline derivative. The method includes the steps of: in the presence of an oxidizing agent, adding a catalyst, then adding aniline or aromatic amine with different substituents, at the same time adding alcohol for reaction so as to prepare the quinoline derivative by one step. Specifically, the catalyst comprises a metal catalyst, an assistant catalyst I and an assistant catalyst II; the metal catalyst is a transition metal catalyst; the assistant catalyst I is an alkaline nitrogen-containing ligand; and the assistant catalyst II is an acidic compound. The quinoline derivative prepared by the method provided by the invention has stable performance and high purity. And the preparation method of the quinoline derivative can prepare quinoline, 2-methylquinoline, 8-hydroxyquinoline quinoline and other derivatives by one-step reaction, and the preparation method is simple and practicable. The preparation process does not produce new "three wastes", is environment-friendly, and provides a green and environment-friendly synthesis method. The preparation method has the characteristics of few raw material variety, little reaction equipment, few preparation step and low cost, and is more suitable for industrial production.
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Paragraph 0071; 0072
(2017/06/02)
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- Blue-light-promoted carbon-carbon double bond isomerization and its application in the syntheses of quinolines
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A blue-light-promoted carbon-carbon double bond isomerization in the absence of any photoredox catalyst is reported. It provides rapid access to a series of quinolines in good to excellent yields under simple aerobic conditions. The protocol is direct, catalyst-free and operationally convenient.
- Chen, Xinzheng,Qiu, Shuxian,Wang, Sasa,Wang, Huifei,Zhai, Hongbin
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supporting information
p. 6349 - 6352
(2017/08/10)
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- H-phosphonate mediated sulfonylation of 2-substituted quinoline N-oxides: One-pot strategy for the synthesis of 3/4-sulfonylquinoline derivatives
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series of biologically important 3/4-sulfonylquinoline derivatives was synthesized starting from easily available sodium benzenesulfinates, diethyl H-phosphonate and 2-substituted quinoline N-oxides in onepot under metal-free conditions. H-phosphonate plays a decisive role in activating the C3-H, C4-H bonds of the 2-substituted quinoline N-oxides. The isolated 3/4-sulfonylquinolines were characterized by 1H, 13CNMR spectroscopy and HR MS.
- Ma, Huili,Liu, Shuyun,Zhu, Shaohua,Bi, Wenzhu,Chen, Xiaolan,Zhao, Yufen
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supporting information
p. 887 - 895
(2017/08/15)
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- Traceless Directing-Group Strategy in the Ru-Catalyzed, Formal [3 + 3] Annulation of Anilines with Allyl Alcohols: A One-Pot, Domino Approach for the Synthesis of Quinolines
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A unique, ruthenium-catalyzed, [3 + 3] annulation of anilines with allyl alcohols in the synthesis of substituted quinolines is reported. The method employs a traceless directing group strategy in the proximal C-H bond activation and represents a one-pot Domino synthesis of quinolines from anilines.
- Kumar, Gangam Srikanth,Kumar, Pravin,Kapur, Manmohan
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supporting information
p. 2494 - 2497
(2017/05/24)
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- Dual behavior of iodine species in condensation of anilines and vinyl ethers affording 2-methylquinolines
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A metal-free, mild and efficient method for the synthesis of 2-methylquinolines was successfully developed by condensation of anilines with vinyl ethers in the presence of catalytic amount of iodine. Modification of both pyridine and benzene moieties was easily achieved by changing only the vinyl ether and aniline. In this reaction, the iodine species was revealed to show dual behavior; molecular iodine serves as an oxidant, while its reduced form, hydrogen iodide, activates the vinyl ether. The redox reaction between these iodine species enables the use of a catalytic amount of iodine in this synthetic method.
- Le, Song Thi,Yasuoka, Chisa,Asahara, Haruyasu,Nishiwaki, Nagatoshi
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- Transition-Metal-Free Regioselective Alkylation of Pyridine N-Oxides Using 1,1-Diborylalkanes as Alkylating Reagents
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Reported herein is an unprecedented base-promoted deborylative alkylation of pyridine N-oxides using 1,1-diborylalkanes as alkyl sources. The reaction proceeds efficiently for a wide range of pyridine N-oxides and 1,1-diborylalkanes with excellent regioselectivity. The utility of the developed method is demonstrated by the sequential C?H arylation and methylation of pyridine N-oxides. The reaction also can be applied for the direct introduction of a methyl group to 9-O-methylquinine N-oxide, thus it can serve as a powerful method for late-stage functionalization.
- Jo, Woohyun,Kim, Junghoon,Choi, Seoyoung,Cho, Seung Hwan
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supporting information
p. 9690 - 9694
(2016/08/10)
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- A Convenient Procedure for the Oxidative Dehydrogenation of N-Heterocycles Catalyzed by FeCl2/DMSO
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A convenient catalytic procedure has been developed for the oxidative dehydrogenations of N-heterocycles. Combining catalytic FeCl2 with DMSO yields a catalyst that promotes the dehydrogenation of tetrahydroquinolines and related heterocycles under 1 bar of O2, affording the corresponding N-heteroaromatic products in moderate yields.
- Zhou, Weiyou,Taboonpong, Piyada,Aboo, Ahmed Hamdoon,Zhang, Lingjuan,Jiang, Jun,Xiao, Jianliang
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supporting information
p. 1806 - 1809
(2016/07/16)
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- Nickel-Catalyzed Alkoxy–Alkyl Interconversion with Alkylborane Reagents through C?O Bond Activation of Aryl and Enol Ethers
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A nickel-catalyzed alkylation of polycyclic aromatic methyl ethers as well as methyl enol ethers with B-alkyl 9-BBN and trialkylborane reagents that involves the cleavage of stable C(sp2)?OMe bonds is described. The transformation has a wide substrate scope and good chemoselectivity profile while proceeding under mild reaction conditions; it provides a versatile way to form C(sp2)?C(sp3) bonds that does not suffer from β-hydride elimination. Furthermore, a selective and sequential alkylation process by cleavage of inert C?O bonds is presented to demonstrate the advantage of this method.
- Guo, Lin,Liu, Xiangqian,Baumann, Christoph,Rueping, Magnus
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supporting information
p. 15415 - 15419
(2016/12/03)
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- Quinolines synthesis by reacting 1,3-butanediol with anilines in the presence of iron catalysts
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2-, 4-, 6-, 7-, and 8-substituted quinolines were synthesized in 78–95% yield by the reaction of 1,3- butanediol with anilines in the presence of iron catalysts in carbon tetrachloride.
- Khusnutdinov,Bayguzina,Aminov
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p. 1613 - 1618
(2016/08/26)
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- Synthesis and Characterization of Iron-Nitrogen-Doped Graphene/Core-Shell Catalysts: Efficient Oxidative Dehydrogenation of N-Heterocycles
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An important goal for nanocatalysis is the development of flexible and efficient methods for preparing active and stable core-shell catalysts. In this respect, we present the synthesis and characterization of iron oxides surrounded by nitrogen-doped-graphene shells immobilized on carbon support (labeled FeOx@NGr-C). Active catalytic materials are obtained in a simple, scalable and two-step method via pyrolysis of iron acetate and phenanthroline and subsequent selective leaching. The optimized FeOx@NGr-C catalyst showed high activity in oxidative dehydrogenations of several N-heterocycles. The utility of this benign methodology is demonstrated by the synthesis of pharmaceutically relevant quinolines. In addition, mechanistic studies prove that the reaction progresses via superoxide radical anions (·O2-).
- Cui, Xinjiang,Li, Yuehui,Bachmann, Stephan,Scalone, Michelangelo,Surkus, Annette-Enrica,Junge, Kathrin,Topf, Christoph,Beller, Matthias
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supporting information
p. 10652 - 10658
(2015/09/28)
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- Discovery and efficient synthesis of a biologically active alkaloid inspired by thiostrepton biosynthesis
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Thiostrepton, a natural peptide macrocycle, is of great interest due to its structural complexity and numerous biological activities, including anti-bacterial, anti-tumor, and anti-plasmodial activities. The quinaldic acid (QA) moiety-containing side ring (loop 2) was proven to play an important role in carrying out these functions. Previously, we proposed biosynthetic logic for thiostrepton loop 2 and demonstrated the formation mechanism of QA. Herein, we report the discovery and efficient synthesis of a biologically active alkaloid, that is, a key intermediate involved in the thiostrepton biosynthetic pathway. A chemo-enzymatic method was performed to synthesize the molecule, and a series of analogs were prepared for bioassays, which included the examination of anti-bacterial and anti-tumor activities.
- Zheng, Qingfei,Wang, Shoufeng,Liu, Wen
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p. 7686 - 7690
(2014/12/10)
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- Mild and general palladium-catalyzed synthesis of methyl aryl ethers enabled by the use of a palladacycle precatalyst
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A general method for the Pd-catalyzed coupling of methanol with (hetero)aryl halides is described. The reactions proceed under mild conditions with a wide range of aryl and heteroaryl halides to give methyl aryl ethers in high yield.
- Cheung, Chi Wai,Buchwald, Stephen L.
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supporting information
p. 3998 - 4001
(2013/09/02)
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- Acceptorless dehydrogenation of nitrogen heterocycles with a versatile iridium catalyst
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Gas up: A cyclometalated iridium complex is found to catalyze the dehydrogenation of various benzofused N-heterocycles, thus releasing H 2. Driven by as low as 0.1 mol % catalyst, the reaction affords quinolines, indoles, quinoxalines, isoquinolines, and β-carbolines in high yields. Copyright
- Wu, Jianjun,Talwar, Dinesh,Johnston, Steven,Yan, Ming,Xiao, Jianliang
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supporting information
p. 6983 - 6987
(2013/07/26)
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- Platinum-catalyzed assembly of quinaldine from aniline and ethylene
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The selectivity of the catalytic reaction between aniline and ethylene in the presence of the Brunet catalyst (PtBr2/Br-) shifts from the hydroamination product N-ethylaniline to the heterocyclization product 2-methylquinoline (quinaldine) when conducted in the presence of PPh3 (1 equiv per Pt atom). Condition optimization revealed that this process works best in the absence of any halide salt additive, that it is essentially insensitive to the nature of the halide in PtX2, that the best promoter in the PMexPh3-x series is PPh3 when used in strictly stoichiometric amounts, and that the 4-RC6H 5NH2 (R = nBu, Cl, OMe, NMe2) substrates are equally converted albeit less efficiently. Slight dilution of the system with THF or toluene slightly improves the activity, and a kinetic profile shows the presence of an induction phase and a deactivating step, which however does not involve reduction to metallic platinum contrary to the PPh3-free Brunet catalyst. Mechanistic considerations are presented.
- Bethegnies, Aurelien,Dub, Pavel A.,Poli, Rinaldo
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p. 1882 - 1891
(2013/05/21)
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- Synthesis of substituted quinolines by the reaction of anilines with alcohols and CCl4 in the presence of Fe-containing catalysts
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Substituted quinolines were synthesized by the reaction of aniline derivatives with aliphatic alcohols and CCl4 upon the action of the FeCl3·6H2O catalyst.
- Khusnutdinov,Bayguzina,Aminov
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p. 133 - 137
(2013/11/19)
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- Facile synthesis of 2-methylquinolines from anilines on mesoporous N-doped TiO2 under UV and visible light
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Nitrogen-doped TiO2 was synthesized by a simple wet method using a nitrogen precursor hydrazine hydrate and nano TiO2. This photocatalyst was characterized by X-ray diffraction, highresolution transmission electron microscopy, diffused reflectance spectra, photoluminescence, and X-ray photoelectron spectroscopy. XPS analysis indicates the incorporation of anionic nitrogen in TiO2 lattice as O-Ti-N linkage. N2 adsorption-desorpion isotherm indicates the mesoporous nature of N-TiO2 with the surface area 130.0 m2/g. Sizes of N-TiO2 particles are found to be in the range of 5-30 nm by HRTEM images. DRS spectra reveal the extended absorption to the visible range. N-TiO2 is found to be more efficient than Ag-TiO2, Au-TiO2, and Pt-TiO2 in quinaldine synthesis under visible light. Copyright Taylor & Francis Group, LLC.
- Selvam,Swaminathan
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p. 500 - 508
(2013/05/21)
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- Design, synthesis and biological evaluation of 2-substituted quinolines as potential antileishmanial agents
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An analogous library of 2-substituted quinoline compounds was synthesized with the aim to identify a potential drug candidate to treat visceral leishmaniasis. These molecules were tested for their in vitro and in vivo biological activity against Leishmania donovani. Metabolic stability of these compounds was also improved through the introduction of halogen substituents. Compound (26g), found to be the most active; exhibited an IC50 value of 0.2 μM and >180 fold selectivity. The hydrochloride salt of (26g) showed 84.26 ± 4.44 percent inhibition at 50 mg/kg × 5 days (twice daily, oral route) dose in L. donovani/hamster model. The efficacy was well correlated with the PK data observed which indicating that the compound is well distributed.
- Gopinath, Vadiraj S.,Pinjari, Jakir,Dere, Ravindra T.,Verma, Aditya,Vishwakarma, Preeti,Shivahare, Rahul,Moger, Manjunath,Kumar Goud, Palusa Sanath,Ramanathan, Vikram,Bose, Prosenjit,Rao,Gupta, Suman,Puri, Sunil K.,Launay, Delphine,Martin, Denis
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p. 527 - 536
(2013/10/22)
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- Mesoporous nitrogen doped nano titania - A green photocatalyst for the effective reductive cleavage of azoxybenzenes to amines or 2-phenyl indazoles in methanol
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A new nitrogen precursor, hydrazine hydrate was used in the synthesis of nano-sized, N-doped TiO2 photocatalyst by a simple wet impregnation method. This photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), High resolution transmission electron microscope (HR-TEM), UV-vis diffuses reflectance spectra (DRS), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). XRD patterns show that the crystal structure of N-TiO2 resembles anatase phase of TiO2. The UV-vis spectra indicate an increase in absorption of visible light when compared to TiO2. Furthermore XPS analysis reveals the presence of the N atom as O-Ti-N linkage substituting the O atom in the TiO2 lattice and this causes a decrease in oxygen vacancies. N-TiO2 nanoparticles were used as a green and recyclable heterogeneous photocatalyst for rapid and efficient reductive cleavage of azoxybenzene into their corresponding amines or 2-phenylindazoles with methanol at room temperature under N2 atmosphere. Azoxybenzenes in neat methanol afforded anilines, while in aqueous methanol (20% water-80% methanol) they formed corresponding 2-phenyl indazoles. In both reductive cleavages, nano N-TiO2 is more effective than prepared TiO2, showing that the nitrogen doping could be an excellent choice to improve the photoactivity of TiO2.
- Selvam,Balachandran,Velmurugan,Swaminathan
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experimental part
p. 213 - 222
(2012/03/26)
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- Nano Pt-TiO2 for an efficient one-pot photocatalytic synthesis of quinaldines from anilines and ethanol
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Nanosized platinum particles loaded on the TiO2 nanoparticles were prepared to assess its photocatalytic activity in simple one-pot synthesis of quinaldines from anilines in ethanol using UV light. The catalyst was characterized by X-ray diffra
- Selvam, Kaliyamoorthy,Sreedhar, Bojja,Swaminathan, Meenakshisundaram
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experimental part
p. 761 - 773
(2012/08/07)
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- One-pot photocatalytic synthesis of quinaldines from nitroarenes with Au loaded TiO2 nanoparticles
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One-pot photocatalytic synthesis of quinaldines from nitroarenes using Au-TiO2 nanoparticles is reported. Au-TiO2 on irradiation induces a combined redox reaction with nitroarene and alcohol and the products undergo condensation-cyclization process to give quinaldines.
- Selvam,Swaminathan
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scheme or table
p. 389 - 393
(2011/12/15)
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- A catalyst-free benzylic C-H bond olefination of azaarenes for direct mannich-like reactions
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A highly efficient synthesis of trans-alkenylazaarene under catalyst-free conditions was developed via the addition of methylazaarenes to N-sulfonyl aldimines and a subsequent C-N elimination in situ. A one-pot procedure for this addition-elimination was also developed. The reaction could tolerate a broad substrate scope and give the corresponding alkenylazaarenes in high yields.
- Yan, Yizhe,Xu, Kun,Fang, Yang,Wang, Zhiyong
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experimental part
p. 6849 - 6855
(2011/10/04)
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- Novel redox photocatalyst Pt-TiO2 for the synthesis of 2-Methylquinolines from nitroarenes
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An eco-friendly and efficient procedure for synthesis of 2-methylquinoline derivatives from nitroarenes has been developed by a simple one-pot reaction on the surface of platinum-loaded TiO2 with neat ethanol under UV irradiation without any harsh reagent according to green chemistry. TiO 2 catalysts with various amounts of Pt loadings were prepared by photodeposition using chloroplatinic acid solution and characterized by XRD, BET, AFM, HR-TEM, XPS, and DRS. XRD patterns showed that the crystal structure of Pt-TiO2 still remained as anatase phase. The UV-vis spectra indicated that Pt promoted the absorption of visible light. The XPS measurements reveal that platinum particles are present mainly in metallic form. AFM and HR-TEM analysis revealed the presence of nonspherical shaped platinum nanoparticles of the diameter 312 nm. Pt-TiO2 on irradiation induces a combined redox reaction with nitroarene and alcohol and this is followed by condensationcyclization of aniline and oxidation products to give 2-methylquinolines
- Selvam, Kaliyamoorthy,Swaminathan, Meenakshisundaram
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experimental part
p. 953 - 959
(2011/10/18)
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- Assembly of substituted 2-alkylquinolines by a sequential palladium-catalyzed Ci-N and Ci-C bond formation
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Diversity: A range of substituted 2-alkylquinolines can be prepared in a general and efficient synthetic approach that employs mild reaction conditions (see scheme). The synthesis is based on a sequential palladium-catalyzed Ci-N and Ci-C bond formation, followed by palladium-catalyzed aromatization, and results in the formation of the desired compounds in one step. Copyright
- Matsubara, Yoshio,Hirakawa, Saori,Yamaguchi, Yoshihiro,Yoshida, Zen-Ichi
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experimental part
p. 7670 - 7673
(2011/10/05)
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- Ruthenium-catalysed synthesis of 2- and 3-substituted quinolines from anilines and 1,3-diols
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A straightforward synthesis of substituted quinolines is described by cyclocondensation of anilines with 1,3-diols. The reaction proceeds in mesitylene solution with catalytic amounts of RuCl3·xH 2O, PBu3 and MgBr2·OEt2. The transformation does not require any stoichiometric additives and only produces water and dihydrogen as byproducts. Anilines containing methyl, methoxy and chloro substituents as well as naphthylamines were shown to participate in the heterocyclisation. In the 1,3-diol a substituent was allowed in the 1- or the 2-position giving rise to 2- and 3-substituted quinolines, respectively. The best results were obtained with 2-alkyl substituted 1,3-diols to afford 3-alkylquinolines. The mechanism is believed to involve dehydrogenation of the 1,3-diol to the 3-hydroxyaldehyde which eliminates water to the corresponding α,β-unsaturated aldehyde. The latter then reacts with anilines in a similar fashion as observed in the Doebner-von Miller quinoline synthesis.
- Monrad, Rune Nygaard,Madsen, Robert
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experimental part
p. 610 - 615
(2011/02/28)
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