1613-41-8Relevant academic research and scientific papers
Manganese catalyzed C-alkylation of methylN-heteroarenes with primary alcohols
Jana, Akash,Kumar, Amol,Maji, Biplab
supporting information, p. 3026 - 3029 (2021/03/29)
C-Alkylations of nine different classes of methyl-substitutedN-heteroarenes, including quinolines, quinoxalines, benzimidazoles, benzoxazoles, pyrazines, pyrimidines, pyridazines, pyridines, and triazines are disclosed. A bench stable earth-abundant Mn(i)-complex catalyzed the chemoselective hydrogen-transfer reaction utilizing a diverse range of primary alcohols as the non-fossil fuel-derived carbon source. The diversifiedN-heteroarenes (41 examples) were isolated in high yields and selectivities. Water is produced as the sole byproduct, making the protocol environmentally benign.
Iron-catalysed alkylation of 2-methyl and 4-methyl azaarenes with alcoholsviaC-H bond activation
Banerjee, Debasis,Bera, Sourajit,Kabadwal, Lalit Mohan
, p. 4777 - 4780 (2020/05/13)
The first Fe-catalysed alkylation of 2-methyl and 4-methyl-azaarenes with a series of alkyl and hetero-aryl alcohols is reported (>39 examples and up to 95% yield). Multi-functionalisation of pyrazines and synthesis of anti-malarial drug (±) Angustureine significantly broaden the scope of this methodology. Preliminary mechanistic investigation, deuterium labeling and kinetic experiments including trapping of the enamine intermediate1a'are of special importance.
Nickel-Catalyzed Dehydrogenation of N-Heterocycles Using Molecular Oxygen
Banerjee, Debasis,Bera, Atanu,Bera, Sourajit
, (2020/09/02)
Herein, an efficient and selective nickel-catalyzed dehydrogenation of five- and six-membered N-heterocycles is presented. The transformation occurs in the presence of alkyl, alkoxy, chloro, free hydroxyl and primary amine, internal and terminal olefin, trifluoromethyl, and ester functional groups. Synthesis of an important ligand and the antimalarial drug quinine is demonstrated. Mechanistic studies revealed that the cyclic imine serves as the key intermediate for this stepwise transformation.
Regiodivergent C-H Alkylation of Quinolines with Alkenes by Half-Sandwich Rare-Earth Catalysts
Lou, Shao-Jie,Zhang, Liang,Luo, Yong,Nishiura, Masayoshi,Luo, Gen,Luo, Yi,Hou, Zhaomin
supporting information, p. 18128 - 18137 (2020/12/02)
The regiodivergent catalysis of C-H alkylation with alkenes is of great interest and importance but has remained hardly explored to date. We report herein the first regiodivergent C-H alkylation of quinolines with alkenes by half-sandwich rare-earth catal
Zirconium-Catalyzed Atom-Economical Synthesis of 1,1-Diborylalkanes from Terminal and Internal Alkenes
Cui, Xin,Jiao, Haijun,Li, Sida,Wang, Xianjin,Wang, Yue,Wu, Lipeng,Xia, Chungu
, p. 13608 - 13612 (2020/06/02)
A general and atom-economical synthesis of 1,1-diborylalkanes from alkenes and a borane without the need for an additional H2 acceptor is reported for the first time. The key to our success is the use of an earth-abundant zirconium-based catalyst, which allows a balance of self-contradictory reactivities (dehydrogenative boration and hydroboration) to be achieved. Our method avoids using an excess amount of another alkene as an H2 acceptor, which was required in other reported systems. Furthermore, substrates such as simple long-chain aliphatic alkenes that did not react before also underwent 1,1-diboration in our system. Significantly, the unprecedented 1,1-diboration of internal alkenes enabled the preparation of 1,1-diborylalkanes.
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.
Alkenylation or alkylation reaction method of alkyl-substituted aza-aromatic hydrocarbon
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Paragraph 0024-0035; 0037-0040, (2020/07/02)
The invention discloses an alkenylation or alkylation reaction method of alkyl-substituted aza-aromatic hydrocarbon. According to the method, alkyl-substituted aza-aromatic hydrocarbon is used as a starting raw material, alcohol is used as an alkenylation or alkylation reagent, alkali is used as an accelerant, a nitrogen-containing or phosphine-containing ligand is used as an auxiliary agent, andan alkenylation or alkylation product is obtained under a heating condition. The method avoids the use of a transition metal catalyst, and has the advantages of easily available raw materials, simpleoperation, mild synthesis reaction conditions, high reaction efficiency, functional group diversity and the like.
Iridium-Catalyzed C-Alkylation of Methyl Group on N-Heteroaromatic Compounds using Alcohols
Onoda, Mitsuki,Fujita, Ken-Ichi
supporting information, p. 7295 - 7299 (2020/10/02)
In this study, we developed a catalytic system for the C-alkylation of a methyl group on N-heteroaromatic compounds, including pyridine, pyrimidine, pyrazine, quinoline, quinoxaline, and isoquinoline, using alcohols based on a hydrogen-borrowing process with [Cp*IrCl2]2 (Cp*: η5-pentamethylcyclopentadienyl) combined with potassium t-butoxide and 18-crown-6-ether as the catalyst precursor.
Sustainable synthesis of N-heterocycles in water using alcohols following the double dehydrogenation strategy
Maji, Milan,Chakrabarti, Kaushik,Panja, Dibyajyoti,Kundu, Sabuj
, p. 93 - 102 (2019/04/05)
The present study describes the first example of synthesis of pharmaceutically relevant N-heterocycles like substituted quinolines, acridines and 1,8-naphthyridines in water under air using alcohols in presence of a new water soluble Ir-complex. The viability and efficiency of this approach was demonstrated by the efficient synthesis of biologically active natural product (±)-galipinine and gram scale synthesis of various N-heteroaromatics. Several kinetic experiments and DFT calculations were carried out to support the plausible reaction mechanism which disclosed that this system followed a concerted outer sphere mechanism for the dehydrogenation of alcohols.
Cobalt-catalyzed alkylation of methyl-substituted N-heteroarenes with primary alcohols: Direct access to functionalized N-heteroaromatics
Mishra, Anju,Dwivedi, Ambikesh D.,Shee, Sujan,Kundu, Sabuj
supporting information, p. 249 - 252 (2019/12/30)
Phosphine free, air and moisture stable Co(NNN) complex catalyzed alkylation of various methyl-substituted N-heteroarenes with alcohols is reported. Following the borrowing hydrogen methodology, a variety of methyl-substituted N-heteroarenes can be functionalized efficiently. To understand the mechanism of this reaction various kinetic and control experiments were carried out.
