3557-61-7Relevant academic research and scientific papers
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
, p. 746 - 756 (2020)
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.
Multi-substituted pyridine derivative and its preparation method
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Paragraph 0076; 0077; 0078; 0079, (2018/01/20)
The invention discloses a polysubstituted pyridine derivative and a preparation method thereof. The derivative has a structure as shown in specification, wherein R1, R2, R3, R4 and R5 all are any one selected from hydrogen atom, halogen atom, alkyl, aryl, substituted aryl, acyl, amino, nitryl and alkoxy; the invention also discloses a preparation method of the polysubstituted pyridine derivative; the preparation method comprises the following steps: by taking acetyenic ketone and 1-arylethylamine as raw materials, and under the action of appropriate alkali, heating to have a reaction in the solvent to obtain the polysubstituted pyridine derivative as shown in the formula at high yield. The preparation method is mild in reaction condition, short in reaction time, wide in substrate range, high in reaction specifity, high in yield and simple in after-treatment.
Synthesis of Highly Substituted Pyridines through Copper-Catalyzed Condensation of Oximes and α,β-Unsaturated Imines
Tan, Wei Wen,Ong, Yew Jin,Yoshikai, Naohiko
supporting information, p. 8240 - 8244 (2017/06/30)
A copper-catalyzed condensation reaction of oxime acetates and α,β-unsaturated ketimines to give pyridine derivatives is reported. The reaction features mild conditions, high functional-group compatibility, and high regioselectivity with respect to unsymmetrical oxime acetates, thus allowing the preparation of a wide range of polysubstituted pyridines, many of which are not readily accessible by conventional condensation methods.
Base-Promoted β-C(sp3)-H Functionalization of Enaminones: An Approach to Polysubstituted Pyridines
Shen, Jinhai,Cai, Dingding,Kuai, Changsheng,Liu, Yunqi,Wei, Ming'E,Cheng, Guolin,Cui, Xiuling
, p. 6584 - 6589 (2015/10/06)
A convenient one-pot base-promoted synthesis of polysubstituted pyridines from 1-arylethylamines and ynones through the direct β-C(sp3)-H functionalization of enaminones under metal-free conditions has been developed. An intermolecular Michael addition reaction and an intramolecular condensation were involved in this procedure, which features high regioselectivity, high efficiency, and environmental friendliness. Various polysubstituted pyridines were provided in up to 92% yield for 34 examples.
2- and 4-(α-Substituted Aryl)pyridines as Leaving Groups in SN2 Reactions and Radicaloid Nucleophilic Displacements.
Katritzky, Alan R.,Elisseou, E. Michael,Bashiardes, George,Patel, Ranjan C.
, p. 301 - 320 (2007/10/02)
Compared with 2,4,6-triphenylpyridine, 2,6-diphenyl-4-(o-substituted phenyl)pyridines as leaving groups in the radicaloid nucleophilic displacement reaction with 2-nitropropanide anion slow down C.T.C. formation. o-Substitution of the 2-phenyl group has little effect on this reaction.The latter modification however decreases SN2 rates of the corresponding pyridiniums with piperidine.
