6829-12-5Relevant academic research and scientific papers
Modular Synthesis of Stereodefined Benzocyclobutene Derivatives via Sequential Cu- And Pd-Catalysis
Talbot, Fabien J. T.,Zhang, Shibo,Satpathi, Bishnupada,Howell, Gareth P.,Perry, Gregory J. P.,Crisenza, Giacomo E. M.,Procter, David J.
, p. 14448 - 14455 (2021/12/01)
Benzocyclobutenes (BCBs) are of growing interest in materials and medicinal chemistry, although general routes for their provision remain underexplored. A modular, divergent, and stereoselective Cu- and Pd-catalyzed assembly/cyclization sequence allows the synthesis of densely functionalized BCBs, from readily accessible imine, allene, and diboron precursors. Preliminary results have identified enantioselective conditions for our protocol and highlighted, for example, its applicability to the synthesis of BCB-containing peptides. By simple variation of experimental conditions or substrate modification, our strategy was expanded to deliver indoline and quinoline derivatives, suitable for further manipulations.
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.
Metal- and Protection-Free [4 + 2] Cycloadditions of Alkynes with Azadienes: Assembly of Functionalized Quinolines
Saunthwal, Rakesh K.,Patel, Monika,Verma, Akhilesh K.
supporting information, p. 2200 - 2203 (2016/06/01)
A base promoted, protection-free, and regioselective synthesis of highly functionalized quinolines via [4 + 2] cycloaddition of azadienes (generated in situ from o-aminobenzyl alcohol) with internal alkynes has been discovered. The reaction tolerates a wide variety of functional groups which has been successfully extended with diynes, (2-aminopyridin-3-yl)methanol, and 1,4-bis(phenylethynyl)benzene to afford (Z)-phenyl-2-styrylquinolines, phenylnaphthyridine, and alkyne-substituted quinolines, respectively. The proposed mechanism and significant role of the solvent were well supported by isolating the azadiene intermediate and deuterium-labeling studies.
Metal free carboamination of internal alkynes - An easy access to polysubstituted quinolines
Stopka,Niggemann
, p. 5761 - 5764 (2016/05/19)
A metal free carboamination of unactivated alkynes towards highly substituted quinolines was realized in the presence of a synergistic Br?nsted acid catalyst system. Supported by mechanistic probes, the reaction proceeds via a highly reactive vinyl cation in a C-C bond formation - Schmidt reaction sequence. The irreversible extrusion of N2, as a powerful driving force, allows for a general conversion of poorly nucleophilic aliphatic alkynes.
Palladium-catalyzed synthesis of polysubstituted quinolines from 2-amino aromatic ketones and alkynes
Zhou, Wang,Lei, Jianhua
supporting information, p. 5583 - 5585 (2014/05/20)
A palladium-catalyzed one-pot method for the synthesis of quinolines from commercial or readily available 2-amino aromatic ketones and alkynes is reported for the first time. This transformation offers an alternative method for the synthesis of polysubstituted quinoline. the Partner Organisations 2014.
Homoleptic vs. heteroleptic orange light-emitting iridium complexes chelated with benzothiazole derivatives
Lee, Hye Joo,Ha, Yunkyoung
, p. 53 - 59 (2014/01/23)
The homoleptic and heteroleptic iridium(III) complexes exhibiting orange phosphorescence were investigated to compare their emission colors, luminance efficiency, and stability. The homoleptic iridium complexes, Ir(pbt-R) 3, were prepared from
Introduction of new ancillary ligands to the iridium complexes having 2,3-diphenylquinolinato ligands for OLED
Lee, Hyun Shin,Ahn, So Youn,Huh, Hyun Sue,Ha, Yunkyoung
experimental part, p. 3325 - 3330 (2010/01/11)
We investigated the effect of an ancillary ligand (AL) on the emission color and luminous efficiencies of its complex, Ir(4-Me-2,3-dpq)2(AL), where 4-Me-2,3-dpq represents 4-methyl-2,3-diphenylquinolinato ligand. We expected that ancillary ligand modification by introduction of the bulky substituent to the complexes might allow luminous efficiency increase by reduction of T-T annihilation. Furthermore, some ancillary ligands may contribute to fine-tuning of their complex emission colors by influencing the energy level of Ir d-orbitals upon the orbital mixing. As new ancillary ligands substituting for acac which is a typical AL in the iridium complexes, pyrazolone-based ligands, 4-R-5-methyl-2-phenyl-2,4-dihydro-pyrazol-3-one series (przl-R), were prepared, where R represents C6H5, C6H4CH3 and C6H4Cl. These ligands were chelated to the iridium center to yield a new series of the iridium complexes, Ir(4-Me-2,3-dpq)2(przl-R). The X-ray crystal structure of Ir(4-Me-2,3-dpq)2(przl-C6H4Cl) was determined. The electrochemical and luminescence properties of the iridium complexes were investigated. The effect of the przl-substituents on the emission colors of the complexes was not significant. On the other hand, the luminous efficiencies of Ir(4-Me-2,3-dpq)2(przl-C6H5) and Ir(4-Me-2,3-dpq)2(przl-C6H4CH3) were higher than that of Ir(4-Me-2,3-dpq)2(acac).
