5395-56-2Relevant academic research and scientific papers
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.
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
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.
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.
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
Nickel-Catalyzed Direct Alkenylation of Methyl Heteroarenes with Primary Alcohols
Baidya, Mahiuddin,Ramakrishna, Isai,Ramalingam, Bose Muthu
, p. 9819 - 9825 (2019/08/26)
An efficient nickel-catalyzed acceptorless dehydrogenative coupling of methyl-substituted heteroarenes with primary alcohols is achieved using an in situ generated complex of inexpensive NiBr2 and readily available 8-aminoquinoline picolinic amide ligand. The protocol is operationally simple and scalable and furnishes a series of high-value 2-alkenylheteroarenes in good yields (up to 88percent) with exclusive E-selectivity. The reaction proceeds with the release of water and molecular hydrogen, which was analyzed through gas chromatography to validate the reaction mechanism. ?
Nickel-catalysed direct α-olefination of alkyl substituted N-heteroarenes with alcohols
Das, Jagadish,Vellakkaran, Mari,Banerjee, Debasis
supporting information, p. 7530 - 7533 (2019/07/04)
Catalytic α-olefination of alkylheteroarenes with primary alcohols via dehydrogenative coupling is presented. A simple nickel catalyst system stabilised by readily available nitrogen ligands enables a series of interesting E-configured vinylarenes (confirmed by X-ray crystal-structure analysis) to be synthesised in good to excellent yields with olefin/alkane selectivity of >20:1. Hydrogen and water are generated as byproducts and quantitative determination of H2 was performed.
