122957-63-5Relevant academic research and scientific papers
Dimetallic Palladium-NHC Complexes: Synthesis, Characterization, and Catalytic Application for Direct C?H Arylation Reaction of Heteroaromatics with Aryl Chlorides
Lee, Jhen-Yi,Ghosh, Debalina,Kuo, Ya-Ting,Lee, Hon Man
, p. 648 - 658 (2020/01/02)
A series of dimetallic palladium(II)-NHC complexes comprised of 1,4-naphthalenyl or 9,10-anthracenyl spacer sandwiched between two imidazole rings was successfully synthesized. These complexes were characterized by 1H and 13C{1H} NMR spectroscopy and elemental analysis. The structures of two dimetallic palladium complexes and a related mononuclear palladium complex to be used for comparative studies were further characterized by X-ray diffraction. The dimetallic palladium complex with the 9,10-anthracenyl linker was very efficient in catalyzing direct C?H arylation reactions of heteroaromatic compounds (imidazoles, imidazo[1,2-a]pyridine, and thioazole) with a broad range of aryl chlorides, employing a mild monopalladium loading of 1.5 mol%.It allows for the effective use of aryl chlorides to prepare arylated heterocycles, previously only accessible with the more reactive bromide counterparts. Importantly, the catalytic activity of the dimetallic precatalyst was found to be higher than that of an analogous mononuclear complex. (Figure presented.).
Highly regioselective CH bond functionalization of imidazo[1,2-a]pyridines with aryl halides catalyzed by Ru-arene complex
Yang, Hai,Yang, Liping,Li, Yuan,Zhang, Fan,Liu, Huajie,Yi, Bing
experimental part, p. 11 - 14 (2012/08/28)
An effective Ru-catalyzed coupling reaction of imidazo[1,2-a]pyridines and aryl halides is reported for the synthesis of polysubstituted imidazo[1,2-a]pyridines through CH bond cleavages. The current study presents a convenient strategy to synthesize poly
Direct arylation of imidazo[1,2-a ]pyridine at C-3 with aryl iodides, bromides, and triflates via copper(I)-catalyzed C-H bond functionalization
Cao, Hua,Zhan, Haiying,Lin, Yuanguang,Lin, Xiulian,Du, Zuodong,Jiang, Huanfeng
supporting information; experimental part, p. 1688 - 1691 (2012/06/18)
A convenient method for the copper(I)-catalyzed arylation of substituted imidazo[1,2-a]pyridine has been developed. This method is applicable to a variety of aryl electrophiles, including bromides, iodides, and triflates. It represents the first general p
1,4-Dihydropyridines as Antagonists of Platelet Activating Factor. 1. Synthesis and Structure-Activity Relationships of 2-(4-Heterocyclyl)phenyl Derivatives
Cooper, Kelvin,Fray, M. Jonathan,Parry, M. John,Richardson, Kenneth,Steele, John
, p. 3115 - 3129 (2007/10/02)
A novel class of 2-(4-heterocyclylphenyl)-1,4-dihydropyridines (2-38) possessing antagonist activity against platelet activating factor (PAF) was prepared by the Hantzsch synthesis from a variety of ethyl 4'-heterocyclic-substituted benzoylacetates, aryl or heteroaryl aldehydes, and substituted 3-aminocrotonamides or 3-aminocrotonate esters.Structure-activity relationships were evaluated where PAF antagonist activity was measured in vitro by determining the concentration of compound (IC50) required to inhibit the PAF-induced aggregation of rabbit washed platelets,and in vivo by determining the oral dose (ED50) which protected mice from a lethal injection of PAF.The nature of the substituent at the dihydropyridine 2-position was found to be important for both in vitro and in vivo activity, whereas there was greater flexibility for structural variation at the 4- and 5-positions.The most potent compound was 4-(2-chlorophenyl)-1,4-dihydro-3-(ethoxycarbonyl)-6-methyl-2-pyrid-1-yl)phenyl>-5-pyridine (17, UK-74,505), IC50 = 4.3 nM, ED50 = 0.26 mg/kg po, which was found to be approximately 33 times more potent in vitro (rabbit platelet aggregation) and about 8 times more potent in vivo (murine lethality) than WEB2086.Compound 17 also exhibited a long duration of action in the dog (inhibition of PAF-induced whole blood aggregation ex vivo was maintained for > 24 h following a single oral dose of 75 μg/kg) and was highly selective as a PAF antagonist, showing only weak affinity (IC50 = 6600 nM) for the nitrendipine binding site.As a result of its high oral potency, selectivity, and duration of action, UK-74,505 has been selected for clinical evaluation.
