14251-81-1Relevant articles and documents
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
, p. 18128 - 18137 (2020)
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
Visible-Light-Mediated Oxidative Cyclization of 2-Aminobenzyl Alcohols and Secondary Alcohols Enabled by an Organic Photocatalyst
Xu, Jing-Xiu,Pan, Nan-Lian,Chen, Jia-Xi,Zhao, Jin-Wu
, p. 10747 - 10754 (2021/08/16)
This paper describes a visible-light-mediated oxidative cyclization of 2-aminobenzyl alcohols and secondary alcohols to produce quinolines at room temperature. This photocatalytic method employed anthraquinone as an organic small-molecule catalyst and DMSO as an oxidant. According to this present procedure, a series of quinolines were prepared in satisfactory yields.
Ruthenium-catalyzed acceptorless dehydrogenative coupling of o-aminobenzyl alcohols with ketones to quinolines in the presence of carbonate salt
Xu, Xiangchao,Ai, Yao,Wang, Rongzhou,Liu, Liping,Yang, Jiazhi,Li, Feng
, p. 340 - 349 (2021/02/27)
A ruthenium complex bearing a functional 2,2′-bibenzimidazole ligand [(p-cymene)Ru(BiBzImH2)Cl][Cl] was designed, synthesized and found to be a general and highly efficient catalyst for the synthesis of quinolines via acceptorless dehydrogenative coupling of o-aminobenzyl alcohols with ketones in the presence of carbonate salt. It was confirmed that NH units in the ligand are crucial for catalytic activity. The application of this catalytic system for the scale-gram synthesis of biologically active molecular was also undertaken. Notably, this research exhibits new potential of metal–ligand bifuctional catalysts for acceptorless dehydrogenative reactions.
Asymmetric Synthesis of Hydroquinolines with α,α-Disubstitution through Organocatalyzed Kinetic Resolution
Chen, Yunrong,Zhu, Chaofan,Guo, Zheng,Liu, Wei,Yang, Xiaoyu
supporting information, p. 5268 - 5272 (2021/02/05)
The first kinetic resolution of hydroquinoline derivatives with α,α-disubstitution has been achieved through asymmetric remote aminations with azodicarboxylates enabled by chiral phosphoric acid catalysis. Mechanistic studies suggest a monomeric catalyst pathway proceeding through rate- and enantio-determining electrophilic attack promoted by a network of attractive non-covalent interactions between the substrate and catalyst. Facile subsequent removal and transformations of the newly introduced hydrazine moiety enable these protocols to serve as powerful tools for asymmetric synthesis of N-heterocycles with α,α-disubstitution.
Kinetic Resolution of 2,2-Disubstituted Dihydroquinolines through Chiral Phosphoric Acid-Catalyzed C6-Selective Asymmetric Halogenations
Chen, Yunrong,He, Yu-Peng,Liu, Wei,Tao, Houchao,Yang, Xiaoyu,Zhao, Fei,Zhu, Chaofan
supporting information, p. 4104 - 4108 (2021/06/27)
A novel kinetic resolution of 2,2-disubstituted dihydroquinolines was achieved by regioselective asymmetric halogenations enabled by chiral phosphoric acid catalysis. A series of dihydroquinolines bearing 2,2-disubstitutions were well-tolerated in these reactions, generating both the recovered dihydroquinolines and C-6-brominated products with high enantioselectivities, with s-factors up to 149. In addition, this kinetic resolution protocol is also applicable for 2,2-disubstituted tetrahydroquinoline and asymmetric iodonation reaction.
Modular Access to Spiro-dihydroquinolines via Scandium-Catalyzed Dearomative Annulation of Quinolines with Alkynes
Lou, Shao-Jie,Luo, Gen,Yamaguchi, Shigeru,An, Kun,Nishiura, Masayoshi,Hou, Zhaomin
supporting information, p. 20462 - 20471 (2021/12/03)
The catalytic enantioselective construction of three-dimensional molecular architectures from planar aromatics such as quinolines is of great interest and importance from the viewpoint of both organic synthesis and drug discovery, but there still exist many challenges. Here, we report the scandium-catalyzed asymmetric dearomative spiro-annulation of quinolines with alkynes. This protocol offers an efficient and selective route for the synthesis of spiro-dihydroquinoline derivatives containing a quaternary carbon stereocenter with an unprotected N-H group from readily accessible quinolines and diverse alkynes, featuring high yields, high enantioselectivity, 100% atom-efficiency, and broad substrate scope. Experimental and density functional theory studies revealed that the reaction proceeded through the C-H activation of the 2-aryl substituent in a quinoline substrate by a scandium alkyl (or amido) species followed by alkyne insertion into the Sc-aryl bond and the subsequent dearomative 1,2-addition of the resulting scandium alkenyl species to the C=N unit in the quinoline moiety. This work opens a new avenue for the dearomatization of quinolines, leading to efficient and selective construction of spiro molecular architectures that were previously difficult to access by other means.
Preparation of 2-Arylquinolines from 2-Arylethyl Bromides and Aromatic Nitriles with Magnesium and N -Iodosuccinimide
Naruto, Hiroki,Togo, Hideo
, p. 1122 - 1130 (2020/04/01)
Treatment of 2-arylethylmagnesium bromides, prepared from 2-arylethyl bromides and magnesium, with aromatic nitriles, followed by reaction with water and then with N -iodosuccinimide under irradiation with a tungsten lamp, gave the corresponding 2-arylquinolines in good to moderate yields under transition-metal-free conditions. 2-Alkylquinolines could be also obtained in moderate yields by the same procedure with 2-arylethyl bromides, magnesium, aliphatic nitriles bearing a secondary alkyl group, and N -iodosuccinimide.
Phosphine Ligand-Free Ruthenium Complexes as Efficient Catalysts for the Synthesis of Quinolines and Pyridines by Acceptorless Dehydrogenative Coupling Reactions
Guo, Bin,Yu, Tian-Qi,Li, Hong-Xi,Zhang, Shi-Qi,Braunstein, Pierre,Young, David J.,Li, Hai-Yan,Lang, Jian-Ping
, p. 2500 - 2510 (2019/05/10)
A series of phosphine-free Ru(III)/Ru(II) complexes of NH functionalized N?N?N pincer ligands exhibit excellent activity for acceptorless dehydrogenative coupling (ADC) of secondary alcohols with 2-aminobenzyl or γ-amino alcohols to quinolines and pyridines. Ru(III) complexes [LRuCl3] (L=6-(3-R1,5-R2-1H-pyrazol-1-yl)-N-(pyridin-2-yl)pyridin-2-amine; 1 a: R1=R2=H (L1); 1 b: R1=R2=Me (L2); 1 c: R1=H, R2=CF3 (L3); 1 d: R1=H, R2=Ph (L4); 1bMe: L=6-(3,5-dimethyl-1H-pyrazol-1-yl)-N-methyl-N-(pyridin-2-yl)pyridin-2-amine (L2Me)) were obtained by refluxing RuCl3 ? xH2O with the corresponding ligand in EtOH. Five Ru(II) complexes [LRu(DMSO-κS)Cl2] (2 a: L=L1; 2 b: L=L2; 2 c: L=L3; 2 d: L=L4; 2bMe: L=L2Me) were formed by reducing the corresponding Ru(III) complex in refluxing EtOH. The latter complexes could also be prepared directly by refluxing Ru(DMSO)4Cl2 with the corresponding ligand in EtOH. These Ru(III) and Ru(II) complexes, especially 1 b/2 b, exhibited high catalytic efficiency and broad functional group tolerance in ADC reactions of secondary alcohols with 2-aminobenzyl or γ-amino alcohols to quinolines and pyridines. A detail mechanistic study indicated the Ru(III) complex was reduced into the Ru(II) species, which is the active catalytic center for ADC via a Ru?H/N?H bifunctional outer-sphere mechanism. This protocol provides a reliable, atom-economical and environmentally benign procedure for C?N and C?C bond formation.
Ligand-controlled phosphine-free Co(II)-catalysed cross-coupling of secondary and primary alcohols
Zhang, Shi-Qi,Guo, Bin,Xu, Ze,Li, Hong-Xi,Li, Hai-Yan,Lang, Jian-Ping
, (2019/10/28)
Cobalt(II) complexes (5 mol% Co) bearing phosphine-free N?N?N pincer ligands efficiently catalyze C–C coupling of secondary and primary alcohols to selectively form α-alkylated ketones with a good functional group compatibility using NaOH (20 mol%) as a base at 120 °C. The NH group on the N?N?N–Co(II) precatalyst controls the activity and selectivity. This simple catalytic system is involved in the synthesis of quinolones via the dehydrogenative annulation of 2-aminobenzyl alcohols with secondary alcohols.
Pd-Catalyzed Tandem Reaction of 2-Aminostyryl Nitriles with Arylboronic Acids: Synthesis of 2-Arylquinolines
Xu, Tong,Shao, Yinlin,Dai, Ling,Yu, Shulin,Cheng, Tianxing,Chen, Jiuxi
, p. 13604 - 13614 (2019/10/16)
A novel palladium-catalyzed protocol for the synthesis of 2-arylquinolines via tandem reaction of 2-aminostyryl nitriles with arylboronic acids has been developed with good functional group tolerance. The presented approach offers a new synthetic pathway toward the core structures of 2-arylquinolines compared to classical condensation reaction of (E)-2-aminostyryl aryl ketones. Moreover, the present synthetic route could be readily scaled up to gram quantity without difficulty. Preliminary mechanistic experiments showed that this transformation involves a nucleophilic addition of aryl palladium species to the nitrile to generate an aryl ketone intermediate followed by an intramolecular cyclization and dehydration to quinoline ring.