- Tetrabutylammonium Bromide-Catalyzed Transfer Hydrogenation of Quinoxaline with HBpin as a Hydrogen Source
-
A metal-free environmentally benign, simple, and efficient transfer hydrogenation process of quinoxaline has been developed using the HBpin reagent as a hydrogen source. This reaction is compatible with a variety of quinoxalines offering the desired tetrahydroquinoxalines in moderate-to-excellent yields with Bu4NBr as a noncorrosive and low-cost catalyst.
- Guo, Qi,Chen, Jingchao,Shen, Guoli,Lu, Guangfu,Yang, Xuemei,Tang, Yan,Zhu, Yuanbin,Wu, Shiyuan,Fan, Baomin
-
p. 540 - 546
(2021/12/27)
-
- Water-involving transfer hydrogenation and dehydrogenation of N-heterocycles over a bifunctional MoNi4 electrode
-
A room-temperature electrochemical strategy for hydrogenation (deuteration) and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi4 electrode is developed, which includes the hydrogenation of quinoxaline using H2O as the hydrogen source with 80% Faradaic efficiency and the reverse dehydrogenation of hydrogen-rich 1,2,3,4-tetrahydroquinoxaline with up to 99% yield and selectivity. The in situ generated active hydrogen atom (H*) is plausibly involved in the hydrogenation of quinoxaline, where a consecutive hydrogen radical coupled electron transfer pathway is proposed. Notably, the MoNi4 alloy exhibits efficient quinoxaline hydrogenation at an overpotential of only 50 mV, owing to its superior water dissociation ability to provide H* in alkaline media. In situ Raman tests indicate that the NiII/NiIII redox couple can promote the dehydrogenation process, representing a promising anodic alternative to low-value oxygen evolution. Impressively, electrocatalytic deuteration is easily achieved with up to 99% deuteration ratios using D2O. This method is capable of producing a series of functionalized hydrogenated and deuterated quinoxalines.
- Han, Shuyan,Huang, Yi,Li, Mengyang,Liu, Cuibo,Zhang, Bin
-
p. 1983 - 1991
(2021/09/02)
-
- New V1a receptor antagonist. Part 1. Synthesis and SAR development of urea derivatives
-
Solid preclinical evidence links vasopressin to social behavior in animals, so, extensive work has been initiated to find new vasopressin V1a receptor antagonists which can improve deteriorated social behavior in humans and can treat the core symptoms of
- Baska, Ferenc,Bata, Imre,Bozó, éva,Cselenyák, Attila,Domány-Kovács, Katalin,Kordás, Krisztina Szondiné,Kurkó, Dalma,Makó, Attila,Mohácsi, Réka,Szántó, Gábor
-
-
- Preparation method of tetrahydroquinoxaline compound
-
The invention relates to the field of preparation methods of organic compounds, in particular to a preparation method of a tetrahydroquinoxaline compound. According to the method, a quinoxaline compound is used as a reaction substrate; the preparation method comprises the following steps: dissolving a rhodium metal catalyst, zinc powder, an additive or a ligand into a dry solvent in an environmentwhich is not in contact with air, namely a nitrogen or argon environment, then adding the quinoxaline reaction substrate, adding water, reacting the mixture at 40-80 DEG C, monitoring the reaction byusing TLC until the substrate is completely consumed, and purifying residues to obtain a target product. The method has the advantages of cheap and easily available reagents, simple process, convenient operation, strong atom economy, and suitableness for routine preparation.
- -
-
Paragraph 0079-0081
(2019/12/02)
-
- Rhodium-catalyzed transfer hydrogenation of quinoxalines with water as a hydrogen source
-
Rhodium-catalyzed transfer hydrogenation of quinoxalines with water as a hydrogen source was reported. The reaction allowed the simple preparation of tetrahydroquinoxalines under mild conditions. The deuterium-labelling experiment confirmed that water is
- Zhang, Xia,Chen, Jingchao,Khan, Ruhima,Shen, Guoli,He, Zhenxiu,Zhou, Yongyun,Fan, Baomin
-
p. 10142 - 10147
(2019/12/26)
-
- B(C6F5)3-Catalyzed Deoxygenative Reduction of Amides to Amines with Ammonia Borane
-
The first B(C6F5)3-catalyzed deoxygenative reduction of amides into the corresponding amines with readily accessible and stable ammonia borane (AB) as a reducing agent under mild reaction conditions is reported. This metal-free protocol provides facile access to a wide range of structurally diverse amine products in good to excellent yields, and various functional groups including those that are reduction-sensitive were well tolerated. This new method is also applicable to chiral amide substrates without erosion of the enantiomeric purity. The role of BF3 ? OEt2 co-catalyst in this reaction is to activate the amide carbonyl group via the in situ formation of an amide-boron adduct. (Figure presented.).
- Pan, Yixiao,Luo, Zhenli,Han, Jiahong,Xu, Xin,Chen, Changjun,Zhao, Haoqiang,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
-
supporting information
p. 2301 - 2308
(2019/01/30)
-
- B(C6F5)3-Promoted hydrogenations of N-heterocycles with ammonia borane
-
A transition-metal-free method for the B(C6F5)3-promoted hydrogenations of N-heterocycles using ammonia borane under mild reaction conditions has been developed. The reaction affords a broad range of hydrogenated products in moderate to good yields. The enantioselective versions for the corresponding products were also investigated via our approach, showing good feasibility.
- Ding, Fangwei,Zhang, Yiliang,Zhao, Rong,Jiang, Yanqiu,Bao, Robert Li-Yuan,Lin, Kaifeng,Shi, Lei
-
supporting information
p. 9262 - 9264
(2017/08/21)
-
- Versatile (Pentamethylcyclopentadienyl)rhodium-2,2′-Bipyridine (Cp?Rh-bpy) Catalyst for Transfer Hydrogenation of N-Heterocycles in Water
-
An investigation employing the catalytic system consisting of (pentamethylcyclopentadienyl)rhodium dichloride dimer [Cp?RhCl2]2 and 2,2′-bipyridine (bpy) for transfer hydrogenation of a variety of quinoxalines, quinoxalinones, quinolines and indoles under aqueous conditions with formate as the hydrogen source is reported. This approach provides various tetrahydroquinoxalines, dihydroquinoxalinones, tetrahydroquinolines and indolines in good to excellent yields. The activity of the catalyst towards quinoxalines and quinoxalinones is excellent, with a substrate to catalyst ratio (S/C) of 10000 being feasible. The choice of ligand is critical to the catalysis, and the aqueous phase reduction is shown to be highly pH-dependent, with acidic pH values needed for optimal reduction. The catalyst is easy to access, and the reaction is operationally simple without requiring an inert atmosphere.
- Zhang, Lingjuan,Qiu, Ruiying,Xue, Xiao,Pan, Yixiao,Xu, Conghui,Li, Huanrong,Xu, Lijin
-
supporting information
p. 3529 - 3537
(2016/01/25)
-
- Synthesis and single crystal structure of novel 1,4-Bis (Dichloroacetyl)-1,2,3,4-tetrahydroquinoxaline Derivatives
-
A series of 1,4-bis (dichloroacetyl)-1,2,3,4-tetrahydroquinoxalines (4) were synthesized by cyclization and acylation reactions with o-phenylenediamine and 1,2- dibromoalkanes as the starting materials in the presence of NaHCO3 as attaching acid agent. The structures of all the compounds were characterized by IR, 1H NMR, 13C NMR, MS and elemental analysis. The single crystal of 3a, 4d and 6 were determined by X-ray crystallography.
- Ye, Fei,Liu, Xin-Ying,Qu, Li-Hua,Fu, Ying,Zhao, Li-Xia,Qu, Hai-Hao
-
p. 167 - 174
(2019/01/21)
-