1945-84-2Relevant articles and documents
Palladium (II) complexes chelated by 1-substituted-4-pyridyl-1H-1,2,3-triazole ligands as catalyst precursors for selective ethylene dimerization
Joseph, Mohammed Cassiem,Swarts, Andrew John,Mapolie, Selwyn Frank
, (2020)
A series of neutral as well as cationic palladium methyl complexes bearing 1-substituted-4-pyridyl-1H-1,2,3-triazole ligands were prepared and fully characterized by a range of analytical techniques. Conventional and 2D NMR spectroscopy as well as single-crystal X-ray diffraction analysis unambiguously determined the molecular structure of the complexes. The neutral complexes activated by methylaluminoxane were found to be effective catalysts in the ethylene dimerization reaction. The catalyst performance of the in-situ-generated active species was compared with the discrete cationic complexes of the same ligand scaffold. Activities and selectivities for the two systems were remarkably similar, pointing to similarities in the nature of the active species. Both catalytic systems showed a strong correlation of activity and selectivity with the nature of the ligand scaffold. Highest activities were attained when electron-withdrawing groups were incorporated into the triazole ring, while increasing steric bulk in the ortho-position on the pyridyl ring of the ligand led to the almost exclusive dimerization of ethylene with selectivities up to 94% observed toward 1-butene.
Synthesis and characterization of 2,5-bis(2-pyridyl)thiophene
Al-Taweel, Samir A.
, p. 1041 - 1045 (2002)
2-[2-(Trimethylsilyl)ethynyl] pyridine (6) was prepared in 95% yield by reaction of 2-bromopyridine with trimethylsilylacetylene in triethylamine in the presence of bis(triphenylphosphine)Palladium(II) chloride and Copper(I) iodide. Desilylation of (6) by refluxing with sodium hydroxide in methanol (yield 95%) of 2-ethynylpyridine (5). Oxidative coupling of (5) in pyridine by oxygen in the presence of Copper(I) chloride gives 70% yield of 1,4-bis(2-pyridyl)1,3-butadiyne (4). Reaction of 4 with sodium sulfide affords 100% of 2,5-bis(2-pyridyl) thiophene (1).
Regio- and stereoselective synthesis of bromoalkenes by homolytic hydrobromination of alkynes with hydrogen bromide
Kumaki, Wataru,Kinoshita, Hidenori,Miura, Katsukiyo
, (2022/03/07)
Homolytic hydrobromination of terminal and internal alkynes with a commercially available solution of hydrogen bromide in acetic acid has been investigated for regio- and stereoselective synthesis of bromoalkenes. Under an aerobic atmosphere at room temperature, the reaction of ethynylarenes with a small excess of HBr efficiently gave (2-bromoethenyl)arenes with good to high E-selectivity. (Alk-1-ynyl)arenes, or internal alkynes bearing both phenyl and alkyl groups at the sp-carbons also underwent the air-initiated hydrobromination to exhibit high Z-selectivity under kinetic conditions using a half equivalent of HBr.
The synthesis of cyclometalated platinum(ii) complexes with benzoaryl-pyridines as C^N ligands for investigating their photophysical, electrochemical and electroluminescent properties
Wang, Dezhi,Chen, Xi,Yang, Hua,Zhong, Daokun,Liu, Boao,Yang, Xiaolong,Yue, Ling,Zhou, Guijiang,Ma, Miaofeng,Wu, Zhaoxin
, p. 15633 - 15645 (2020/11/24)
A series of (C^N)Pt(acac)-type complexes has been successfully synthesized with a benzo[b]furan, benzo[b]thiophene, benzo[b]selenophene, or benzo[b]tellurophene group in the benzoaryl-pyridine ligand. Using X-ray crystallography, the chemical structures o
BTK Inhibitors and uses thereof
-
Paragraph 1600; 1606-1608, (2020/05/02)
The invention discloses a bruton's tyrosine kinase (BTK) inhibitor and use thereof. Specifically, the invention provides heteroaromatic compounds or stereoisomers, geometrical isomers, tautomers, racemates, nitrogen oxides, hydrates, solvates, metabolites and pharmaceutically acceptable salts or prodrugs thereof, and pharmaceutical compositions containing the heteroaromatic compounds; the invention also discloses use of the heteroaromatic compounds or the pharmaceutical compositions containing the heteroaromatic compounds in preparation of medicines; the medicines can be used for treating autoimmune diseases, inflammatory diseases or proliferative diseases.
Design and characterization of a heterocyclic electrophilic fragment library for the discovery of cysteine-targeted covalent inhibitors
Keeley,ábrányi-Balogh,Keseru
supporting information, p. 263 - 267 (2019/03/05)
A fragment library of electrophilic small heterocycles was characterized through cysteine-reactivity and aqueous stability tests that suggested their potential as covalent warheads. The analysis of theoretical and experimental descriptors revealed correlations between the electronic properties of the heterocyclic cores and their reactivity against GSH that are helpful in identifying suitable fragments for cysteines with specific nucleophilicity. The most important advantage of these fragments is that they show only minimal structural differences from non-electrophilic counterparts. Therefore, they could be used effectively in the design of targeted covalent inhibitors with minimal influence on key non-covalent interactions.
Synthesis and structural studies of 1,4-di(2-pyridyl)-1,2,3-triazole dpt and its transition metal complexes; A versatile and subtly unsymmetric ligand
McCarney, Eoin P.,Hawes, Chris S.,Blasco, Salvador,Gunnlaugsson, Thorfinnur
, p. 10209 - 10221 (2016/07/06)
The synthesis of the 'click' derived 1,4-di(2-pyridyl)-1,2,3-triazole (dpt) chelator/ligand from 2-azidopyridine and 2-ethynylpyridine using Cu(i) and TBTA by microwave assisted synthesis is presented. The complexes of the subtly unsymmetric dpt ligand with Cu(i), Pt(ii), Co(ii), and Ag(i) were structurally characterised by using conventional methods, as well as using single crystal and powder diffraction analysis. The results of the studies showed formation of discrete molecules displaying preferential binding of the d-metal cations through the pyridyl nitrogen N1 and the proximal triazolyl nitrogen N2 i.e. the 2-(1H-1,2,3-triazol-4-yl)pyridine or 'regular' chelate moiety despite the presence of a second potential binding pocket i.e. the 2-(1H-1,2,3-triazol-1-yl)pyridine chelate or 'inverse' moiety. This binding selectivity was corroborated through the study of the self-assembly of dpt with Cu(i) and Ag(i) using 1H NMR titration in CD3CN solution, as well as using UV-Vis absorption titrations; the former showing a broadening of the proton peaks associated with that chelate pocket.
A dramatic enhancing effect of InBr3 towards the oxidative Sonogashira cross-coupling reaction of 2-ethynylanilines
Ikeda,Omote,Kusumoto,Komori,Tarui,Sato,Ando
supporting information, p. 2127 - 2133 (2016/02/18)
The addition of InBr3 to the oxidative Sonogashira cross-coupling reaction of 2-ethynylaniline with (E)-trimethyl(3,3,3-trifluoroprop-1-enyl)silane led to a dramatic increase in the reactivity to afford the corresponding 1,3-enynes bearing a trifluoromethyl group on their terminal sp2 carbon. The subsequent cyclization of these 1,3-enynes under palladium catalysis provides access to the corresponding indoles bearing a 3,3,3-trifluoroprop-1-enyl group at their 2-position.
Metal cation binding to acetylenic tetrathiafulvalene–pyridine conjugates: affinity tuned by preorganization and cavity size
Broman, S?ren Lindb?k,Andersen, Cecilie Lindholm,Jevric, Martyn,Tortzen, Christian Gregers,Hammerich, Ole,Nielsen, Mogens Br?ndsted
, p. 5831 - 5842 (2016/09/07)
A series of three structurally related mono-, bidentate and macrocyclic TTF-pyridine hosts were prepared and titrated with several metal cations including Ag+and Pb2+and studied using NMR- and UV–vis spectroscopy and cyclic voltammetry. For Ag+, we found an eightfold increase in binding affinity between the bidentate and macrocyclic host and conversely, for Pb2+, a 100-fold drop. Density functional theory (DFT) calculations support the increased binding affinity for Ag+is due to an N?N distance for the uncomplexed macrocycle very much suited for binding of Ag+but being too small for Pb2+. The bidentate host, on the other hand, is of a suitable size for Pb2+.
The Role of Substituent Effects in Tuning Metallophilic Interactions and Emission Energy of Bis-4-(2-pyridyl)-1,2,3-triazolatoplatinum(II) Complexes
Prabhath, M. R. Ranga,Romanova, Julia,Curry, Richard J.,Silva, S. Ravi P.,Jarowski, Peter D.
, p. 7949 - 7953 (2015/06/30)
The photoluminescence spectra of a series of 5-substituted pyridyl-1,2,3-triazolato PtII homoleptic complexes show weak emission tunability (ranging from λ=397-408 nm) in dilute (10-6 M) ethanolic solutions at the monomer level and strong tunability in concentrated solutions (10-4 M) and thin films (ranging from λ=487-625 nm) from dimeric excited states (excimers). The results of density functional calculations (PBE0) attribute this "turn-on" sensitivity and intensity in the excimer to strong Pt-Pt metallophilic interactions and a change in the excited-state character from singlet metal-to-ligand charge transfer (1MLCT) to singlet metal-metal-to-ligand charge transfer (1MMLCT) emissions in agreement with lifetime measurements. Turn-on tunability: A series of bis-4-(2-pyridyl)-1,2,3-triazolatoplatinum(II) complexes display variable emission tunability. At low concentration, the emission can be tuned only slightly by changing the nature of the substituent but at higher concentrations tunability is enhanced. This "turn-on" sensitivity in the excimeric emission is attributed to strong Pt-Pt metallophilic interactions and a change in the excited-state character.
