15994-89-5Relevant academic research and scientific papers
Cyclometallated compounds of manganese(I) with 1-methylphenylimidazoles
Suarez, Antonio,Vila, Jose Manuel,Pereira, Maria Teresa,Gayoso, Eduardo,Gayoso, Miguel
, p. 359 - 364 (1987)
Cyclometallated complexes of manganese(1) with 1-methylphenylimidazoles have been prepared.IR and 1H NMR spectroscopic studies show they are octahedral complexes in which the imidazole ligand is bound to the metal through the nitrogen and phenyl C(6) atom
Nano CuO-catalyzed C-H functionalization of 1,3-azoles with bromoarenes and bromoalkenes
Zhang, Wu,Tian, Yujie,Zhao, Na,Wang, Yuanyuan,Li, Jia,Wang, Zhenghua
, p. 6120 - 6126 (2015/03/30)
Copper oxide catalyzed direct C-H arylation and alkenylation of aromatic heterocycles using aryl and alkenyl bromides have been developed and have been applied to the C-H functionalization of a variety of 1,3-azoles like benzoxazole, benzothiazole, 1-methylbenzimidazole, and 1-methylimidazole, with moderate to excellent yields. The best performance has been achieved in the presence of PPh3 when average size of CuO nanoparticles is 6.5 nm. This catalyst can be recovered and reused without significant decrease in its catalytic activity.
One pot Pd(OAc)2-catalysed 2,5-diarylation of imidazoles derivatives
Takfaoui, Abdelilah,Zhao, Liqin,Touzani, Rachid,Soulé, Jean-Fran?ois,Dixneuf, Pierre H.,Doucet, Henri
, p. 8316 - 8323 (2015/03/04)
The regioselective 2- or 5-arylation of imidazole derivatives with aryl halides using palladium catalysts has been described in recent years; whereas the arylation at both C2 and C5 carbons of imidazoles in high yields has not been performed. We found con
Ambivalent role of metal chlorides in ring opening reactions of 2H-azirines: Synthesis of imidazoles, pyrroles and pyrrolinones
Auricchio, Sergio,Truscello, Ada M.,Lauria, Mirvana,Meille, Stefano V.
experimental part, p. 7441 - 7449 (2012/09/22)
2H-Azirines were found to react with imines, enaminones and enaminoesters in the presence of metal salts. Imidazoles, pyrroles and new pyrrolinones derivatives are isolated in good overall yields. The role of metal salts was investigated as they can act as Lewis acids or electron donors. Mechanisms are proposed suggesting that imidazoles arise from addition of azirine to imines via radical or ionic mechanism; pyrroles and pyrrolinones are obtained from azirines with enamino derivatives when the salt acts as a Lewis acid. In the latter case the properties of the metallic compound influence the reaction regioselectivity.
Direct C5-arylation reaction between imidazoles and aryl chlorides catalyzed by palladium complexes with phosphines and N-heterocyclic carbenes
Kumar, P. Vijaya,Lin, Wu-Shien,Shen, Jiun-Shian,Nandi, Debkumar,Lee, Hon Man
experimental part, p. 5160 - 5169 (2011/11/14)
Palladium(II) acetate complexes bearing phosphines and carbene ligands, Pd(L)(PR3)(OAc)2 (1a, R = Ph; 1b, R = Cy; L = 1,3-dibenzylimidazol-2-ylidene), were prepared by salt metathesis reactions of their chloro complexes with AgOAc in good yields. The electron-rich 1b was efficient in catalyzing C-5 direct arylation of imidazoles with aryl halides. Most significantly, the catalytic system allows a range of aryl chlorides as substrates. Microwave irradiation effectively promotes the reactions, with good yields obtainable in only 2 h. In combination with the classical method of C-C bond formation reactions, novel imidazole derivatives featuring biaryl and styryl subunits were successfully obtained from 1,4-dichlorobenzene and 1-bromo-4-chlorobenzene.
Direct arylation of simple azoles catalyzed by 1,10-phenanthroline containing palladium complexes: An investigation of C4 arylation of azoles and the synthesis of triarylated azoles by sequential arylation
Shibahara, Fumitoshi,Yamaguchi, Eiji,Murai, Toshiaki
experimental part, p. 2680 - 2693 (2011/06/20)
Direct triarylation and sequential triarylation reactions of simple azoles catalyzed by [Pd(phen)2]PF6 are described. Simple azoles, such as N-methylimidazole, thiazole, and oxazole, were observed to undergo triaryaltion reactions even at their C4 positions when treated with aryl iodides in the presence of [Pd(phen)2]PF6 as a catalyst and a stoichiometric amount of Cs2CO3 in DMA at 150 °C. Using excess amounts of azoles, selective C5 monoarylation was achieved by using the same catalytic system. Subsequent efforts demonstrated that C5 arylated azoles undergo exclusive C2 arylation using [Pd(phen)2]PF6 as the catalyst with galvinoxyl as an additive. Finally, unprecedented C4 arylation reactions of 2,5-diaryl-azoles occur by using the new catalytic system to give the corresponding triarylated products in good to excellent yields. The results of mechanistic studies suggest that the C2 arylation process takes place by way of an electrophilic aromatic substitution (SEAr) palladation pathway, while arylation reactions at the C4 position occur via a SEAr palladation and/or radical mechanism. Finally, a concise, three-step synthesis of the Tie-2 Tyrosine Kinase Inhibitor has been executed starting with commercially available N-methylimidazole by a route that employs the new sequential arylation process.
Cyclometalated iridium(III) complexes based on phenyl-imidazole ligand
Baranoff, Etienne,Fantacci, Simona,De Angelis, Filippo,Zhang, Xianxi,Scopelliti, Rosario,Graetzel, Michael,Nazeeruddin, Md. Khaja
, p. 451 - 462 (2011/03/16)
Phenyl-imidazole-based ligands with various substitution patterns have been used as the main ligand for heteroleptic bis-cyclometalated iridium complexes. Two series of complexes have been prepared and their photophysical and electrochemical properties we
Catalyst-controlled regioselective suzuki couplings at both positions of dihaloimidazoles, dihalooxazoles, and dihalothiazoles
Strotman, Neil A.,Chobanian, Harry R.,He, Jiafang,Guo, Yan,Dormer, Peter G.,Jones, Christina M.,Steves, Janelle E.
supporting information; experimental part, p. 1733 - 1739 (2010/05/18)
(Chemical Equation Presentation) Various dihaloazoles can be monoarylated at a single C-X bond with high selectivity via Suzuki coupling. By changing the palladium catalyst employed, the selectivity can be switched for some dihaloazoles, allowing for Suzuki coupling at the other, traditionally less reactive C-X bond. These conditions are applicable to coupling of a wide variety of aryl-, heteroaryl-, cyclopropyl-, and vinylboronic acids with high selectivities and enable the rapid construction of diverse arrays of diarylazoles in a modular fashion.
Palladium-Catalyzed Arylation of Azole Compounds with Aryl Halides in the Presence of Alkali Metal Carbonates and the Use of Copper Iodide in the Reaction
Pivsa-Art, Sommai,Satoh, Tetsuya,Kawamura, Yoshiki,Miura, Masahiro,Nomura, Masakatsu
, p. 467 - 473 (2007/10/03)
The reactions of iodobenzene with azole compounds, 1,2-disubstituted imidazoles and 2-substituted oxazoles and thiazoles, were examined in the presence of catalytic amounts of Pd(OAc)2 and PPh3 in DMF using alkali metal carbonates as bases. It was found that the coupling products, 5-arylazoles, could be selectively produced in good yields by using CS2CO3. In the case that their 2-position is unsubstituted, the site could also be arylated. In reactions using bromobenzene in place of iodobenzene, K2CO3 was also as effective as Cs2CO3- The addition of a stoichiometric amount of Cul appeared to specifically promote the reactions of thiazoles as well as those of thiophene derivatives. The reactions of 2-unsubstituted azole compounds with aryl iodides could be mediated by Cul to some extent without using the palladium species to give 2-arylazoles.
