- Regiodivergent C-H Alkylation of Quinolines with Alkenes by Half-Sandwich Rare-Earth Catalysts
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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
- Lou, Shao-Jie,Zhang, Liang,Luo, Yong,Nishiura, Masayoshi,Luo, Gen,Luo, Yi,Hou, Zhaomin
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- Ruthenium-catalyzed acceptorless dehydrogenative coupling of o-aminobenzyl alcohols with ketones to quinolines in the presence of carbonate salt
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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.
- Xu, Xiangchao,Ai, Yao,Wang, Rongzhou,Liu, Liping,Yang, Jiazhi,Li, Feng
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p. 340 - 349
(2021/02/27)
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- Visible-Light-Mediated Oxidative Cyclization of 2-Aminobenzyl Alcohols and Secondary Alcohols Enabled by an Organic Photocatalyst
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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.
- Xu, Jing-Xiu,Pan, Nan-Lian,Chen, Jia-Xi,Zhao, Jin-Wu
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p. 10747 - 10754
(2021/08/16)
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- Asymmetric Synthesis of Hydroquinolines with α,α-Disubstitution through Organocatalyzed Kinetic Resolution
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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.
- Chen, Yunrong,Zhu, Chaofan,Guo, Zheng,Liu, Wei,Yang, Xiaoyu
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supporting information
p. 5268 - 5272
(2021/02/05)
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- Kinetic Resolution of 2,2-Disubstituted Dihydroquinolines through Chiral Phosphoric Acid-Catalyzed C6-Selective Asymmetric Halogenations
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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.
- Chen, Yunrong,He, Yu-Peng,Liu, Wei,Tao, Houchao,Yang, Xiaoyu,Zhao, Fei,Zhu, Chaofan
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supporting information
p. 4104 - 4108
(2021/06/27)
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- Modular Access to Spiro-dihydroquinolines via Scandium-Catalyzed Dearomative Annulation of Quinolines with Alkynes
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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.
- Lou, Shao-Jie,Luo, Gen,Yamaguchi, Shigeru,An, Kun,Nishiura, Masayoshi,Hou, Zhaomin
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supporting information
p. 20462 - 20471
(2021/12/03)
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- Preparation of 2-Arylquinolines from 2-Arylethyl Bromides and Aromatic Nitriles with Magnesium and N -Iodosuccinimide
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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.
- Naruto, Hiroki,Togo, Hideo
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p. 1122 - 1130
(2020/04/01)
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- Pd-Catalyzed Tandem Reaction of 2-Aminostyryl Nitriles with Arylboronic Acids: Synthesis of 2-Arylquinolines
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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.
- Xu, Tong,Shao, Yinlin,Dai, Ling,Yu, Shulin,Cheng, Tianxing,Chen, Jiuxi
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p. 13604 - 13614
(2019/10/16)
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- Phosphine Ligand-Free Ruthenium Complexes as Efficient Catalysts for the Synthesis of Quinolines and Pyridines by Acceptorless Dehydrogenative Coupling Reactions
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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.
- Guo, Bin,Yu, Tian-Qi,Li, Hong-Xi,Zhang, Shi-Qi,Braunstein, Pierre,Young, David J.,Li, Hai-Yan,Lang, Jian-Ping
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p. 2500 - 2510
(2019/05/10)
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- Ligand-controlled phosphine-free Co(II)-catalysed cross-coupling of secondary and primary alcohols
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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.
- Zhang, Shi-Qi,Guo, Bin,Xu, Ze,Li, Hong-Xi,Li, Hai-Yan,Lang, Jian-Ping
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- Cooperative Organocatalysis: A Systematic Investigation of Covalently Linked Organophosphoric Acids for the Stereoselective Transfer Hydrogenation of Quinolines
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A series of covalently linked bis- and trisphosphoric acids was investigated for their application in the stereoselective transfer-hydrogenation of quinolines. In a combined experimental and theoretical study, it was found that the number and relative pos
- Th?lke, Simon,Zhu, Hui,Jansen, Dennis,Octa-Smolin, Frescilia,Thiele, Maike,Kaupmees, Karl,Leito, Ivo,Grimme, Stefan,Niemeyer, Jochen
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p. 5190 - 5195
(2019/06/08)
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- Synthesis of 2-Substituted Quinolines from 2-Aminostyryl Ketones Using Iodide as a Catalyst
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A new protocol for the synthesis of 2-substituted quinolines from 2-aminostyryl ketones has been developed using iodide as a nucleophilic catalyst. Conjugate addition of iodide to 2-aminostyryl ketones yielded the corresponding β-iodoketones, which could have a conformation where the amino and carbonyl groups are proximal through free rotation about the Cα-Cβ single bond. Subsequent condensation between the amino and carbonyl groups followed by elimination of hydrogen iodide provided the corresponding quinolines, with regeneration of the iodide catalyst.
- Lee, So Young,Jeon, Jiye,Cheon, Cheol-Hong
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p. 5177 - 5186
(2018/05/15)
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- Functional Mechanically Interlocked Molecules: Asymmetric Organocatalysis with a Catenated Bifunctional Br?nsted Acid
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Interlocked molecules, such as catenanes, rotaxanes, and molecular knots, have become interesting candidates for the development of sophisticated chemical catalysts. Herein, we report the first application of a catenane-based catalyst in asymmetric organo
- Mitra, Raja,Zhu, Hui,Grimme, Stefan,Niemeyer, Jochen
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supporting information
p. 11456 - 11459
(2017/09/12)
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- An efficient synthesis of quinolines via copper-catalyzed C-N cleavage
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An efficient method to synthesize substituted quinolines from ketones and 2-amino benzylamines is described. Copper-catalyzed C-N cleavage of amines followed by condensation with ketones deliver quinolines in moderate to high yields. The broad scope of su
- Xi, Long-Yi,Zhang, Ruo-Yi,Zhang, Lei,Chen, Shan-Yong,Yu, Xiao-Qi
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p. 3924 - 3930
(2015/03/30)
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- ONO pincer type Pd(II) complexes: Synthesis, crystal structure and catalytic activity towards C-2 arylation of quinoline scaffolds
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Four new palladium(II) complexes featuring ONO pincer type hydrazone ligands were synthesized and characterized by spectroscopic and single-crystal XRD analysis. These complexes showed excellent catalytic activity towards the Suzuki-Miyaura cross coupling reaction of 2-chloroquinoline derivatives with various aryl boronic acids. The main advantages over previous methodologies include low catalyst loading, less problematic reaction media (H2O-DMF (80:20%)) and a lower reaction temperature of 60 °C for optimal performance.
- Arumugam, Vignesh,Kaminsky, Werner,Nallasamy, Dharmaraj
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p. 77948 - 77957
(2015/09/28)
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- Highly enantioselective spinol-derived phosphoric acid catalyzed transfer hydrogenation of diverse C=N-containing heterocycles
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A highly efficient and enantioselective hydrogenation of diversely substituted C=N-containing heterocyclic compounds such as 3-aryl-1,4-benzoxazines and 2-arylquinolines was experimentally explored by using 1,1′-spirobiindane-7,7′-diol-derived chiral phosphoric acids as the catalyst. This method provides straightforward access to the corresponding tetrahydroquinolines and dihydro-2H-1,4-benzothiazines in high yields (85-99%) with excellent enantioselectivities (91-99%). The attractive features of this procedure, which include mild reaction conditions, operational simplicity, relatively low catalyst loading (1 mol-%), and high levels of enantioselectivities, make it a useful approach for the practical synthesis of optically active nitrogen-containing aromatic heterocycles.
- Zhang, Yiliang,Zhao, Rong,Bao, Robert Li-Yuan,Shi, Lei
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supporting information
p. 3344 - 3351
(2015/05/20)
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- Chiral phosphoric acid catalyzed oxidative kinetic resolution of cyclic secondary amine derivatives including tetrahydroquinolines by hydrogen transfer to imines
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A chiral Bronsted acid catalyzed dehydrogenative kinetic resolution of tetrahydroquinoline derivatives, which are representative of cyclic secondary amines, based on their hydrogen transfer to aromatic imines was efficiently achieved with high enantioselectivities. This hydrogen transfer of tetrahydroquinolines to imines was not driven by their aromatization to quinolines. This dehydrogenative kinetic resolution could be also applied to the asymmetric synthesis of various benzofused heterocycles containing secondary amine cores.
- Saito, Kodai,Miyashita, Hiromitsu,Akiyama, Takahiko
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supporting information
p. 16648 - 16651
(2015/11/25)
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- N-heterocyclic carbene (NHC)-modulated Pd/Cu cocatalyzed three-component synthesis of 2,6-diarylquinolines
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Two new NHC adducts of cyclopalladated ferrocenylpyrazine complexes 1-2 have been prepared and characterized. An efficient NHC-modulated Pd/Cu cocatalyzed three-component coupling reaction for the synthesis of 2,6-diarylquinolines from aminobenzyl alcohol
- Xu, Chen,Li, Hong-Mei,Yuan, Xiao-Er,Xiao, Zhi-Qiang,Wang, Zhi-Qiang,Fu, Wei-Jun,Ji, Bao-Ming,Hao, Xin-Qi,Song, Mao-Ping
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p. 3114 - 3122
(2014/05/06)
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- One-pot synthesis of functionalized p-terphenyl derivatives
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A one-pot synthetic route for preparing functionalized p-terphenyl derivatives 1 and 4 is developed. The route is easily carried from the treatment of cinnamyl aldehydes 2 with substituted allylsulfones 3 in good yields via the tandem intermolecular aldol condensation/intramolecular electrocyclization/ oxidative dehydrogenation.
- Chang, Meng-Yang,Chan, Chieh-Kai,Wu, Ming-Hao
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p. 7916 - 7924
(2013/08/23)
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- Single-operation deracemization of 3H-indolines and tetrahydroquinolines enabled by phase separation
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The single-operation deracemization of 3H indolines and tetrahydroquinolines is described. An asymmetric redox approach was employed, in which a phosphoric acid catalyst, oxidant, and reductant are present in the reaction mixture. The simultaneous presence of both oxidant and reductant was enabled by phase separation and resulted in the isolation of highly enantioenriched starting materials in high yields.
- Lackner, Aaron D.,Samant, Andrew V.,Toste, F. Dean
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supporting information
p. 14090 - 14093
(2013/10/21)
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- Rh(I)-catalyzed direct arylation of azines
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The Rh(I)-catalyzed direct arylation of azines has been developed. Quinolines and 2-substituted pyridines couple with aryl bromides to efficiently afford ortho-arylated azine products using the commercially available and air-stable catalyst [RhCl(CO)2]2. Electron-deficient and electron-rich aromatic bromides couple in good yields, and hydroxyl, chloro, fluoro, trifluoromethyl, ether, and ketone functionalities are compatible with the reaction conditions. Aroyl chlorides also serve as effective azine coupling partners to give ortho-arylation products via a decarbonylation pathway.
- Berman, Ashley M.,Bergman, Robert G.,Ellman, Jonathan A.
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supporting information; experimental part
p. 7863 - 7868
(2011/02/21)
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- Phosphorescent Materials
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Phosphorescent organometallic materials are provided, comprising at least one 3-arylacetylacetone ligand. Processes for making such materials, and to organic light emitting devices comprising the materials, are also provided.
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Page/Page column 3
(2009/10/18)
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- Rh(I)-catalyzed direct arylation of pyridines and quinolines
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A Rh(I)-catalyzed direct arylation of pyridine and quinoline heterocycles has been developed. The method provides rapid entry into an important class of substituted heterocycles employing inexpensive and readily available starting materials. Copyright
- Berman, Ashley M.,Lewis, Jared C.,Bergman, Robert G.,Ellman, Jonathan A.
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supporting information; experimental part
p. 14926 - 14927
(2009/03/12)
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