5395-56-2Relevant 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.
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.
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.
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.
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.
Push–Pull (Iso)quinoline Chromophores: Synthesis, Photophysical Properties, and Use for White-Light Emission
Ibrahim Mohamed Allaoui, Zaina,le Gall, Estelle,Fihey, Arnaud,Plaza-Pedroche, Rodrigo,Katan, Claudine,Robin-le Guen, Fran?oise,Rodríguez-López, Julián,Achelle, Sylvain
, p. 8153 - 8161 (2020/06/02)
The photophysical properties of a series of conjugated push–pull (iso)quinolines were studied. The compounds were synthesized by well-established and straightforward methodologies. The materials exhibited not only emission solvatochromism in a variety of
MnO2 mediated sequential oxidation/olefination of alkyl-substituted heteroarenes with alcohols
Zhang, Chunyan,Li, Zehua,Fang, Yanchen,Jiang, Shaohua,Wang, Maorong,Zhang, Guoying
supporting information, (2020/02/15)
A practical and efficient ligand-free MnO2 mediated sequential oxidation and olefination has been developed for the facile synthesis of a broad range of unsaturated N-heteroazaarenes from simple alkyl-substituted heteroarenes and alcohols. The procedure tolerates a series of functional groups, such as methoxyl, chloro, bromo, iodo, vinyl, phenolic and hetero groups, providing the olefination products in moderate to good yields.The protocol could be conducted at mild conditions and used environmentally friendly air as the clear oxidant.
Direct Alkenylation of 2-Methylquinolines with Aldehydes through Synergistic Catalysis of 1,3-Dimethylbarbituric Acid and HOAc
Liang, En,Wang, Junqi,Wu, Yinrong,Huang, Liangbin,Yao, Xingang,Tang, Xiaodong
supporting information, p. 3619 - 3623 (2019/07/10)
An efficient and practical direct alkenylation of 2-methylquinolines with aldehydes has been achieved through a novel synergistic organocatalysis. The HOAc- activated 2-methylquiolines undergo a Michael addition to 1,3-dimethylbarbituric acid-activated aldehydes, followed by a retro-Michael addition to release 1,3-dimethylbarbituric acid and the target products. The transformation produced various 2-alkenylquinolines with good to excellent yields and featured mild reaction conditions, atom- and step-economy, good functional group tolerance, and operational simplicity. (Figure presented.).
Iron-Catalyzed Coupling of Methyl N-Heteroarenes with Primary Alcohols: Direct Access to E-Selective Olefins
Das, Jagadish,Vellakkaran, Mari,Sk, Motahar,Banerjee, Debasis
supporting information, p. 7514 - 7518 (2019/10/02)
An efficient Fe-catalyzed system is reported for direct α-olefination of methyl-substituted N-heteroarenes with primary alcohols. The catalytic dehydrogenative coupling enables a series of functionalized E-olefinated N-heteroaromatics with excellent selectivity (>99%). Initial mechanistic studies including deuterium-labeling experiments provide evidence for the participation of the benzylic C-H/D bond of alcohols.
