38101-69-8Relevant articles and documents
Ru(II)–NNO pincer-type complexes catalysed E-olefination of alkyl-substituted quinolines/pyrazines utilizing primary alcohols
Balamurugan, Gunasekaran,Malecki, Jan Grzegorz,Ramesh, Rengan,Tamilthendral, Veerappan
, (2022/01/08)
An efficient and selective E-olefination of alkyl-substituted quinolines and pyrazines through acceptorless dehydrogenative coupling of alcohols catalysed by Ru(II)–N^N^O pincer-type complexes encompassing carbonyl and triphenylarsines as co-ligands is de
Nickel(II)-Catalyzed Selective (E)-Olefination of Methyl Heteroarenes Using Benzyl Alcohols via Acceptorless Dehydrogenative Coupling Reaction
Balamurugan, Gunasekaran,Ramesh, Rengan
, (2021/11/30)
An efficient catalytic protocol for the synthesis of selective (E)-olefins by the newly synthesized nickel complexes via greener acceptorless dehydrogenative coupling methodology is presented. Two nickel(II) N, S chelating complexes were structurally characterized with the aid of spectral and single crystal X-ray diffraction methods. Olefination of 2-methylheteroarenes with benzyl alcohols via acceptorless dehydrogenative coupling is achieved by inexpensive nickel(II) catalysts. The present olefination protocol is simple and furnishes the desired 2-alkenylheteroarenes in 35 h and yields in the range of 40–93 %. The dehydrogenative coupling reaction proceeds via the generation of an aldehyde intermediate and produces water and hydrogen as sole by-products. The wide substrate scope of this catalytic reaction covered the synthesis of drug intermediates.
Deaminative Olefination of Methyl N-Heteroarenes by an Amine Oxidase Inspired Catalyst
Thorve, Pradip Ramdas,Maji, Biplab
supporting information, p. 542 - 547 (2021/01/26)
We explored the bioinspired o-quinone cofactor catalyzed aerobic primary amine dehydrogenation for a cascade olefination reaction with nine different methyl N-heteroarenes, including pyrimidines, pyrazines, pyridines, quinolines, quinoxolines, benzimidazoles, benzoxazoles, benzthiazoles, and triazines. An o-quinone catalyst phd (1,10-phenanthroline-5,6-dione) combined with a Br?nsted acid catalyzed the reaction. N-Heteroaryl stilbenoids were synthesized in high yields and (E)-selectivities under mild conditions using oxygen (1 atm) as the sole oxidant without needing transition-metal salt, ligand, stoichiometric base, or oxidant.
NH4I-mediated sp3 C-H cross-dehydrogenative coupling of benzylamines with 2-methylquinoline for the synthesis of E-2-styrylquinolines
Huang, Bin,Li, Xue,Liao, WeiBo,Wang, JiangWei,Zhang, YuanYuan
, p. 903 - 910 (2021/07/17)
Without any metal catalyst, a simple and efficient method for the synthesis of E-2-styrylquinolines through sp3 C-H cross-dehydrogenative coupling of benzylamines with 2-methylquinolines mediated by NH4I under air is successfully developed. The oxidative olefination proceeded through deamination and sp3 C–H bond activation. A plausible mechanism is proposed for the construction of E-2-styrylquinolines.
Method for alkenylation of methyl heterocyclic compound
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Paragraph 0099-0102, (2021/02/10)
The invention discloses a method for alkenylation of methyl heterocyclic compound, which is a green method for synthesizing an alkenyl heterocyclic compound by carrying out alkenylation reaction on methyl under the condition that the methyl heterocyclic compound and alcohol do not need to participate in a transition metal catalyst. According to the method, alcohol which is cheap, easy to obtain, wide in source, stable and low in toxicity is used as an alkenylation reagent, no transition metal catalyst or ligand is needed, air can be directly used as a convenient, mild and efficient oxidizing agent under the action of common water-soluble inorganic base, and the method is suitable for industrial production. The alkenyl heterocyclic compound is directly synthesized by carrying out a Cenylation reaction with a methyl heterocyclic compound through processes such as oxidative condensation and the like. The method has the advantages of simple reaction conditions, no need of inert gas protection, low requirements on equipment, easiness in operation, water as a byproduct, easiness in removal of water-soluble inorganic base, no metal residue in the product, easiness in purification, suitability for heterocyclic systems such as quinoline, quinoxaline, pyridine, benzothiazole and the like, and wide application range, thereby having certain research significance and potential application prospect.
Metal-Free Synthesis of Alkenylazaarenes and 2-Aminoquinolines through Base-Mediated Aerobic Oxidative Dehydrogenation of Benzyl Alcohols
Batra, Sanjay,Dahatonde, Dipak J.,Ghosh, Aritra
, p. 2746 - 2751 (2021/06/25)
A metal-free, base-mediated, and atom-efficient oxidative dehydrogenative coupling of substituted phenylmethanols (benzyl alcohols) with methyl azaarenes or phenylacetonitriles to afford substituted alkenylazaarenes or 2-aminoquinolines, respectively is described. CsOH.H2O was discovered to be the base of choice for obtaining optimal yields of the title compounds, although the reaction could proceed with KOH as well. The protocol that works efficiently in the presence of air is amenable over broad range of substrates.
Waste-minimized synthesis of C2 functionalized quinolines exploiting iron-catalysed C-H activation
Ferlin, Francesco,Zangarelli, Agnese,Lilli, Simone,Santoro, Stefano,Vaccaro, Luigi
, p. 490 - 495 (2021/01/28)
Herein we present an efficient and regioselective iron-catalyzed methodology for the external oxidant-free functionalization of quinoline-N-oxides. The protocol, based on the use of inexpensive and easily accessible FeSO4, showed broad applicability to a wide range of substrates. An additional green feature of this synthetic methodology is H2O being the only by-product. Experimental and computational investigations provide support to a mechanism based on a facile C-H activation event. The green efficiency of the process has also been carefully assessed using: (i) metrics related to the synthetic process (AE, Yield, 1/SF, MRP and RME); (ii) safety/hazard metrics (SHZI and SHI); and (iii) metrics related to the metal used as the catalyst (Abundance, OEL and ADP). In addition to the many advantages of this protocol related to the green iron catalyst used and the safety/hazard features of the process, an E-factor value of ca. 0.92 (84 to >99% reduction compared to known protocols) evidently confirms the sustainable efficiency of the procedure presented. Practical utility has also been demonstrated by performing the reaction efficiently on a multi-gram scale. This journal is
Malononitrile-activated synthesis and anti-cholinesterase activity of styrylquinoxalin-2(1: H)-ones
Bharate, Sandip B.,Kapoor, Kamal K.,Mahajan, Sheena,Nuthakki, Vijay K.,Slathia, Nancy
, p. 15966 - 15975 (2020/05/13)
Herein, we report a base-free malononitrile activated condensation of 3-methylquinoxaline-2(1H)-one (3MQ) 1 with aryl aldehydes 3a-3ad for synthesis of styrylquinoxalin-2(1H)-ones (SQs) 4a-4ad with excellent yields. In this reaction, malononitrile activates the aldehyde via Knoevenagel condensation towards reaction with 3MQ 1 and gets liberated during the course of reaction to yield the desired SQs 4a-4ad. The SQs were evaluated for in vitro cholinesterase inhibition and 4n was found to display a mixed type of inhibition of AChE, which was supported by molecular modelling studies. This study has led to the discovery of a new chemotype for cholinesterase inhibition which might be useful in finding a remedy for Alzheimer's disease.
NaCl as Catalyst and Water as Solvent: Highly E-Selective Olefination of Methyl Substituted N-Heteroarenes with Benzyl Amines and Alcohols
Hazra, Susanta,Tiwari, Vikas,Verma, Ashutosh,Dolui, Pritam,Elias, Anil J.
supporting information, p. 5496 - 5501 (2020/07/14)
Oxidative coupling of benzylamines and alcohols with methyl substituted N-heteroarenes such as quinolines and quinoxalines has been achieved using chloride, a sea abundant anion as the catalyst for practical synthesis of a wide range of E-disubstituted olefins in aqueous medium. Detailed mechanistic studies and control experiments were carried out to deduce the reaction mechanism which indicated that in situ formed ClO2- is the active form of the catalyst. We have successfully carried out a 1 g scale reaction using this methodology, and five pharmaceutically relevant conjugated olefins were also synthesized by this method in moderate to good yields.
Aryl-Nickel-Catalyzed Benzylic Dehydrogenation of Electron-Deficient Heteroarenes
Zhang, Pengpeng,Huang, David,Newhouse, Timothy R.
supporting information, p. 1757 - 1762 (2020/02/04)
This manuscript describes the first practical benzylic dehydrogenation of electron-deficient heteroarenes, including pyridines, pyrazines, pyrimidines, pyridazines, and triazines. This transformation allows for the efficient benzylic oxidation of heteroarenes to afford heterocyclic styrenes by the action of nickel catalysis paired with an unconventional bromothiophene oxidant.
