5278-58-0Relevant articles and documents
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.
Synthesis of quinolines through copper-catalyzed intermolecular cyclization reaction from anilines and terminal acetylene esters
Zheng, Zhilei,Deng, Guobo,Liang, Yun
, p. 103478 - 103481 (2016/11/13)
A simple and convenient copper-catalyzed intermolecular cyclization reaction for the synthesis of quinolines from anilines and terminal acetylene esters has been developed. This methodology constructs the C-N and C-C bonds successively via a cascade process, and provides the desired products in moderate to good yields.
Iron-catalyzed direct C-H arylation of heterocycles and quinones with arylboronic acids
Deb, Arghya,Manna, Srimanta,Maji, Arun,Dutta, Uttam,Maiti, Debabrata
supporting information, p. 5251 - 5256 (2013/09/02)
The arylation of C-H bonds to generate heteroaryl-aryl (Het-Ar) and arylated quinone (Quin-Ar) compounds has received great attention to achieve sustainable goals in synthetic chemistry. Despite significant advances, arylation of a broad range of Het-Ar and Quin-Ar derivatives remains a challenging task. Herein, a variety of heterocycles are arylated by using arylboronic acids in the presence of catalytic amounts of inexpensive Fe(NO 3)3. The C-arylated quinone compounds can be prepared by reacting arylboronic acids with either quinone or hydroquinone. The present method is operationally simple, scalable, does not require prefunctionalization of the heterocycle or quinone, and can tolerate a wide variety of functional groups in the coupling partners. These qualities are expected to render this method attractive for academic and industrial use. Direct C-H arylation of a variety of heterocycles and quinones with arylboronic acids has been developed. An inexpensive iron catalyst, Fe(NO3)3, and a co-oxidant, persulfate, were used in air. The protocol is applicable for large-scale synthesis and is expected to find application as a result of its operational simplicity. Copyright
