6808-65-7Relevant academic research and scientific papers
A Domino Heck Coupling-Cyclization-Dehydrogenative Strategy for the One-Pot Synthesis of Quinolines
Ghora, Santanu,Sreenivasulu, Chinnabattigalla,Satyanarayana, Gedu
, p. 393 - 402 (2021/10/21)
An efficient, one-pot, domino synthesis of quinolines via the coupling of iodoanilines with allylic alcohols facilitated by palladium catalysis is described. The overall synthetic process involves an intermolecular Heck coupling between 2-iodoanilines and allylic alcohols, intramolecular condensation of in situ generated ketones with an internal amine functional group, and a dehydrogenation sequence. Notably, this protocol occurs in water as a green solvent. Significantly, the method exhibits broad substrate scope and is applied for the synthesis of deuterated quinolines through a deuterium-exchange process.
SmI2-mediated C-alkylation of Ketones with Alcohols under Microwave Conditions: A Novel Route to Alkylated Ketones
Gour, Jitendra,Kar, Swayamsiddha,Mahammad Ghouse, Shaik,Manohar Chelli, Sai,Nanduri, Srinivas,Pawar, Gaurav,Reddy Dannarm, Srinivas,Sonti, Rajesh
, (2022/03/15)
A novel protocol is developed towards the preparation of alkylated ketones from alcohols in presence of catalytic amount of SmI2 and base with the elimination of water as a single by-product under microwave irradiation conditions. Furthermore, applicability of this methodology to the synthesis of Donepezil and late-stage functionalization in Pregnenolone is also reported. Successful application of this methodology in Friedl?nder quinolone synthesis using 2-aminobenzyl alcohol and various acetophenones expand the synthetic utility of this protocol.
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.
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.
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.
NiH-Catalyzed Hydroamination/Cyclization Cascade: Rapid Access to Quinolines
Chen, Qian,Gao, Yang,Hu, Xiao-Qiang,Huo, Yanping,Li, Xianwei,Yang, Simin
, p. 7772 - 7779 (2021/06/30)
Despite the significant success of metal-H-catalyzed hydroamination methodologies, considerable limitations still exist in the selective hydroamination of alkynes, especially for terminal alkynes. Herein, we develop a highly efficient NiH catalytic system that activates readily available alkynes for a cascade hydroamination/cyclization reaction with anthranils. This mild, operationally simple protocol is amenable to a wide array of alkynes including terminal and internal, aryl and alkyl, electron-deficient and electron-rich ones, delivering structurally diverse quinolines in useful to excellent yields (>80 examples, up to 93% yield). The utility of this procedure is exhibited in the late-stage functionalization of several natural products and in the concise synthesis of an antitumor molecule graveolinine and a triplex DNA intercalator. Preliminary mechanistic experiments suggest an alkenylnickel-mediated alkyne hydroamination and an intramolecular cyclization/aromatization of putative enamine intermediates.
Continuous Flow Synthesis of Quinolines via a Scalable Tandem Photoisomerization-Cyclization Process
Di Filippo, Mara,Baumann, Marcus
, p. 6199 - 6211 (2020/08/26)
A continuous photochemical process is presented that renders a series of quinoline products via an alkene isomerization and cyclocondensation cascade. It is demonstrated that a high-power LED lamp generates the desired targets with higher productivity and efficiency than a medium-pressure Hg-lamp. The scope of this tandem process is established and allows for the generation of various substituted quinolines in high yields and with throughputs of greater than one gram per hour. Finally, this effective flow process is coupled with a telescoped hydrogenation reaction to render a series of tetrahydroquinolines including the antimalarial natural product galipinine.
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.
A nanoscale iron catalyst for heterogeneous direct: N - And C -alkylations of anilines and ketones using alcohols under hydrogen autotransfer conditions
Nallagangula, Madhu,Sujatha, Chandragiri,Bhat, Venugopal T.,Namitharan, Kayambu
supporting information, p. 8490 - 8493 (2019/07/22)
Here, we report a commercially available nanoscale Fe catalyst for heterogeneous direct N- and C-alkylation reactions of anilines and methyl ketones with alcohols. A hydrogen autotransfer mechanism has been found to operate in these reactions by deuterium labelling studies. In addition, dehydrogenative quinoline synthesis has been demonstrated from amino benzyl alcohols and acetophenones.
