3557-63-9Relevant academic research and scientific papers
Metal-Free Synthesis of 2,4,6-Trisubstituted Pyridines via Iodine-Initiated Reaction of Methyl Aryl Ketones with Amines under Neat Heating
Xu, Hui,Zeng, Ji-Chao,Wang, Fang-Jian,Zhang, Ze
, p. 1879 - 1883 (2017)
A neat heating protocol has been developed for metal-free synthesis of various 2,4,6-trisubstituted pyridines via iodine-initiated (in situ generated HI-catalyzed) condensation of methyl aryl ketones with amines and the following cyclization-aerobic oxidation. Large-scale synthesis and mechanistic investigation were also performed.
Pyridine Skeleton Synthesis Using Acetonitrile as C4N1 Units and Solvent
Bai, Chaolumen,Guo, Huifang,Liu, Xin,Liu, Dan,Sun, Zhaorigetu,Bao, Agula,Baiyin, Menghe,Muschin, Tegshi,Bao, Yong-Sheng
, p. 12664 - 12675 (2021/09/18)
The first [3 + 2 + 1] methodology for pyridine skeleton synthesis via cascade carbopalladation/cyclization of acetonitrile, arylboronic acids, and aldehydes was developed. This reaction proceeds via six step tandem reaction sequences involving the carbopalladation reaction of acetonitrile, a nucleophilic addition, a condensation, an intramolecular Michael addition, cyclization, and aromatization. Delightfully, both palladium acetate and supported palladium nanoparticles catalyzed this reaction with similar catalytic performance. The characterization results of the fresh and used supported palladium nanoparticle catalysts indicated that the reaction might be performed via a Pd(0)/Pd(II) catalytic cycle that began with Pd(0). Furthermore, the products showed good fluorescence characteristics. The green homogeneous/heterogenous catalytic methodologies pave a new way for constructing the pyridine skeleton.
Cyclometalated pt complexes of cnc pincer ligands: Luminescence and cytotoxic evaluation
Garbe, Simon,Krause, Maren,Klimpel, Annika,Neundorf, Ines,Lippmann, Petra,Ott, Ingo,Brünink, Dana,Strassert, Cristian A.,Doltsinis, Nikos L.,Klein, Axel
supporting information, p. 746 - 756 (2020/03/30)
In the framework of our attempts to develop cyclometalated Pt(II) complexes toward bifunctional targeting inhibitors or agents for photodynamic therapy, diagnostics, and bioimaging, a series of bis-cyclometalated Pt(II) complexes [Pt(CNC)(L)] (L = DMSO, MeCN) containing various (CNC)2- ligands based on 2,6-diphenylpyridine were synthesized and characterized analytically and spectroscopically, focusing on their electrochemical, luminescence, and antiproliferative properties. Electrochemical experiments and UV-vis absorption spectroscopy suggest ligand-centered LUMOs and metal-centered HOMOs in line with DFT calculations. Extension of the ancillary phenyl to naphthyl cores and a central 4-phenylpyridine group instead of pyridine results in bathochromic shifts of the long-wavelength absorption bands ranging from 420 to 440 nm, with the latter shift being more pronounced. The complexes of the fused CNC heterocyclic systems dba (H2dba = dibenzo[c,h]acridine), db(ph)a (H2db(ph)a = 7-phenyldibenzo[c,h]acridine), and bzqph (HbzqphH = 2-phenylbenzo[h]quinoline) absorb far more red-shifted in the range 500-530 nm. All complexes show reversible first electrochemical reductions and irreversible oxidations with an electrochemical gap of about 3 V, roughly in line with the absorption energies. While the 2,6-diphenylpyridine complexes [Pt(CNC)(DMSO)] show no luminescence at ambient temperature in solution, the fused dba, db(ph)a, and bzqph derivatives are efficient triplet emitters at ambient temperature with emission wavelengths in the region 575-600 nm and quantum yields ranging from 7 to 23%. Vibrationally resolved emission spectra calculated in the framework of DFT faithfully reproduce the experimental data. TD-DFT calculations at the excited-state T1 geometry reveal intraligand π-π*/MLCT character of the emission for all three investigated complexes. Antiproliferative tests on selected complexes gave very different toxicities, ranging from lower than 1 μM to virtually nontoxic. The data allowed drawing some structure-activity relationships (SAR), even though variations in solubility could also significantly account for the different toxicities.
Merrifield resin-supported quinone as an efficient biomimetic catalyst for metal-free, base-free, chemoselective synthesis of 2,4,6-trisubstituted pyridines
Yang, Qing,Zhang, Yilin,Zeng, Wei,Duan, Zheng-Chao,Sang, Xinxin,Wang, Dawei
supporting information, p. 5683 - 5690 (2019/10/22)
Metal-free, base-free, biomimetic and chemoselective synthesis of 2,4,6-trisubstituted pyridines was developed under mild conditions for the first time. The heterogeneous biomimetic catalyst-recoverable Merrifield resin-supported quinone-was fully characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometry (XPS) and energy dispersive X-ray spectroscopy (EDX). This supported quinone catalyst exhibited excellent catalytic reactivity for chemoselective synthesis of 2,4,6-trisubstituted pyridines, providing an efficient and green method for the synthesis of pyridine derivatives under mild conditions. Mechanistic investigations were conducted to gain insights into the heterogeneous biomimetic catalyst as well as the resulting transformation. The successful capture of intermediates offered direct and clear evidence for the proposed mechanism.
One-Pot Synthesis of Benzene and Pyridine Derivatives via Copper-Catalyzed Coupling Reactions
Han, Jianwei,Guo, Xin,Liu, Yafeng,Fu, Yajie,Yan, Rulong,Chen, Baohua
supporting information, p. 2676 - 2681 (2017/08/16)
A highly efficient one-pot synthesis of polysubstituted pyridine has been achieved through copper-catalyzed oxidative sp3 C?H coupling of acetophenones with toluene derivatives. Besides, the polysubstituted benzene was obtained through copper-catalyzed coupling of acetophenones. Both of the reactions exhibited a good functional group tolerance to produce a 2,4,6-triphenylpyridine or 1,3,5-triarylbenzene in high yields. Compared with previous methods, these transformations allow a highly flexible and efficient preparation of substituted pyridines and benzenes. (Figure presented.).
Acid-catalyzed tandem reaction for the synthesis of pyridine derivatives via C=C/C(sp3)-N bond cleavage of enones and primary amines
Mao, Zhong-Yuan,Liao, Xiao-Yun,Wang, Heng-Shan,Wang, Chun-Gu,Huang, Ke-Bin,Pan, Ying-Ming
, p. 13123 - 13129 (2017/03/11)
A one-pot acid-catalyzed tandem reaction has been developed without any metallic reagents or extra oxidants. This reaction involves a C=C bond cleavage of enones via a “masked” reverse Aldol reaction, and C(sp3)-N bond cleavage of primary amines to provide nitrogen sources for the assembly of pyridine derivatives in high yields with excellent functional group tolerance.
Synthesis of symmetrical pyridines by iron-catalyzed cyclization of ketoxime acetates and aldehydes
Yi, Yukun,Zhao, Mi-Na,Ren, Zhi-Hui,Wang, Yao-Yu,Guan, Zheng-Hui
, p. 1023 - 1027 (2017/08/18)
A novel and facile iron-catalyzed cyclization of ketoxime acetates and aldehydes for the green synthesis of substituted pyridines has been developed. In the presence of a FeCl3 catalyst, this reaction exhibited a good functional group tolerance to produce 2,4,6-triarylsubstituted symmetrical pyridines in high yields in the absence of any additive. A gram-scale reaction sequence was performed to demonstrate the scaled-up applicability of this synthetic method.
Copper-catalyzed formal C-N bond cleavage of aromatic methylamines: Assembly of pyridine derivatives
Huang, Huawen,Ji, Xiaochen,Wu, Wanqing,Huang, Liangbin,Jiang, Huanfeng
, p. 3774 - 3782 (2013/06/05)
An efficient copper-catalyzed C-N bond cleavage of aromatic methylamines was developed to construct pyridine derivatives. With neat conditions and facile operation, the fragment-assembling strategy affords a broad range of 2,4,6-trisubstituted pyridines in up to 95% yield from simple and readily available starting materials. Interestingly, when pyridin-2-yl methylamine was employed as the substrate, α-alkylation reaction of ketones readily occurred to give β-(pyridin-2-yl) ketones instead of the 2,4,6-trisubstituted pyridines.
Copper-Catalyzed coupling of oxime acetates with aldehydes: A new strategy for synthesis of pyridines
Ren, Zhi-Hui,Zhang, Zhi-Yuan,Yang, Bing-Qin,Wang, Yao-Yu,Guan, Zheng-Hui
, p. 5394 - 5397 (2011/12/02)
Copper-catalyzed coupling of oxime acetates with aldehydes offers a new strategy for the synthesis of highly substituted pyridines. This novel method tolerates a wide range of functionality and allows for rapid elaboration of the oxime acetates into a variety of substituted pyridines.
