86844-02-2Relevant academic research and scientific papers
PROCESS FOR PRODUCING N-(HETERO)ARYLAZOLES
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Page/Page column 47; 48, (2013/03/28)
The present invention provides a process for effectively producing an N-(hetero)arylazole with high yield, which is useful as a medical or agrochemical product, an organic photoconductor material, an organic electroluminescent element material, or the like. The present invention relates to a process for producing an N-(hetero)arylazole, which includes reacting a (hetero)aryl (pseudo)halide with an NH-azole in the presence of: a catalyst including a palladium compound and a coordination compound; and a basic magnesium compound.
Modular synthesis of indoles from imines and o-dihaloarenes or o-chlorosulfonates by a Pd-catalyzed cascade process
Barluenga, Jose,Jimenez-Aquino, Agustin,Aznar, Fernando,Valdes, Carlos
supporting information; experimental part, p. 4031 - 4041 (2009/09/04)
A detailed study of the scope of a new Pd-catalyzed synthesis of indolesfrom 1,2-dihaloarenes and o-halobenzene sulfonates and imines is descri bed. The cascade reaction comprises an imine a-arylation ollowed by an intramolecular C-N bond-forming reaction promoted by the same Pd catalyst. The reaction with 1,2-dibromobenzene shows wide scope and allows the introduction of aryl, alkyl, and vinyl substituents at different positions of the five-membered ring of the indole. The regioselective synthesis of indoles substituted in the six-membered ring can be carried out by employing o-dihalobenzene derivatives with two different halogens, taking advantage of the different reactivities of I, Br, and Cl in oxidative addition reactions. This paper also introduces a method for the efficient cleavage of the N-t-butyl group, thus allowing for the preparation of N-H indoles through the same methodology. Finally, the reaction with o-halosulfonates has been studied. The best substrates are o-chlorononaflates, which lead to indoles in very high yield. The reaction is particularlyappropriate for the synthesis of the challenging 6-substituted indoles. In view of the availability of o-chlorophenols, which are direct precur sors of the chlorononaflates, this reaction represents an efficient entry into indoles substituted in the six-membered ring. The concept is illustrated by the preparation of a 4,6-disubstituted indole from naturally occurring anethole.
An efficient, mild, and selective Ullmann-type N-arylation of indoles catalyzed by copper(I) complex
Rao, R. Koteshwar,Naidu, Ajay B.,Jaseer,Sekar, Govindasamy
experimental part, p. 4619 - 4624 (2009/10/09)
A wide range of N-arylated indoles are selectively synthesized through intermolecular C(aryl)-N bond formation from the corresponding aryl iodides and indoles through Ullmann-type coupling reactions in the presence of a catalytic amount of easily availabl
Highly practical "ligand-free-like" copper-catalyzed N-arylation of azoles in lower nitrile solvents
Zhu, Rui,Xing, Lixin,Wang, Xinyan,Cheng, Chuanjie,Su, Deyong,Hu, Yuefei
supporting information; experimental part, p. 1253 - 1257 (2009/06/18)
In lower nitrile solvents, the N-arylation of azoles with aryl halides was achieved efficiently in the presence of copper powder without any additional ligands. Thus, the first nitrile type of monodentate ligand-mediated, "ligand-free-like" copper-catalyzed N-arylation procedure was established.
The azaallylic anion as a synthon for Pd-catalyzed synthesis of heterocycles: domino two- and three-component synthesis of indoles
Barluenga, Jose,Jimenez-Aquino, Agustin,Valdes, Carlos,Aznar, Fernando
, p. 1529 - 1532 (2008/04/05)
(Chemical Equation Presented) Piecing it all together with palladium: Two- and three-component cascade processes that are promoted by a multifunctional Pd catalyst lead to indoles in a highly efficient manner (see scheme). The key step is the Pd-catalyzed α-arylation of imines with o-dihalobenzene derivatives.
Efficient synthesis of indoles using [3,3]-sigmatropic rearrangement of N-trifluoroacetyl enehydrazines
Miyata, Okiko,Takeda, Norihiko,Kimura, Yasuo,Takemoto, Yoshiji,Tohnai, Norimitsu,Miyata, Mikiji,Naito, Takeaki
, p. 3629 - 3647 (2007/10/03)
[3,3]-Sigmatropic rearrangement of N-trifluoroacetyl enehydrazines provides a novel method for the construction of indoles. N-Trifluoroacetyl enehydrazine having a cyclopentene ring smoothly underwent [3,3]-sigmatropic rearrangement followed by cyclizatio
Palladium-catalyzed tandem alkenyl and aryl C-N bond formation: A cascade N-annulation route to 1-functionalized indoles
Willis, Michael C.,Brace, Gareth N.,Holmes, Ian P.
, p. 403 - 406 (2007/10/03)
(Chemical Equation Presented) A single tandem operation allows rapid access to a variety of substituted N-functionalized indoles. The nitrogen atom of the indole nucleus is incorporated through Pd-catalyzed aryl and alkenyl C-N bond-forming reactions (see scheme; dba = dibenzylideneacetone). Amine, aniline, amide, carbamate, and sulfonamide functional groups can be introduced efficiently.
One-pot synthesis of indoles from ketones and hydrazines under mild reaction conditions
Miyata,Kimura,Naito
, p. 1635 - 1638 (2007/10/03)
A facile one-pot method is presented for the synthesis of indoles via condensation of ketone with hydrazine followed by acylation and rearrangement. This convenient synthetic method provides an easy and simple access to indoles.
Thermal cyclization of N-trifluoroacetyl enehydrazines under mild conditions: A novel entry into the Fischer indole synthesis
Miyata, Okiko,Kimura, Yasuo,Muroya, Kanami,Hiramatsu, Hajime,Naito, Takeaki
, p. 3601 - 3604 (2007/10/03)
An efficient thermal cyclization of N-trifluoroacetyl enehydrazines for the synthesis of indoles is described.
Reactions of Diarylnitrenium Ions with Electron Rich Alkenes: An Experimental and Theoretical Study
Moran, Ricardo J.,Cramer, Christopher,Falvey, Daniel E.
, p. 2742 - 2751 (2007/10/03)
Photolysis of N-(diphenylamino)-2,4,6-trimethylpyridinium tetrafluoroborate (1a) and N-[bis(4-methylphenyl)amino]-2,4,6-trimethylpyridinium salt (1b) gives products attributable to diarylnitrenium ion (Ar2N+, 2). The major products of these reactions include products from nucleophilic addition of various π-nucleophiles (e.g. electron rich alkenes) to the ortho and para positions of one of the phenyl rings. Nanosecond and EPR spectroscopy show that radicals also form. These radicals are thought to give rise to the diarylamines isolated as minor products from the photolysis of la and 1b. In addition to the para addition products and Ph2NH, N-phenylindoles and N-phenylindolinones are isolated when silyl enol ethers and silyl ketene acetals are used as trapping agents, respectively. The indoles and indolinones are generated from initial addition of the nucleophile to the ortho position on 2 followed by cyclization of the resulting intermediate. A product resulting from N addition of the nucleophile to 2 is isolated only when silyl ketene acetals are used. A number of electronic sturcture calculations at different levels of molecular orbital and density functional theory were carried out on Ph2N+. There do not seem to be effects associated with either the charge distribution or the LUMO that would strongly influence ortho/para/N selectivity in nucleophilic trapping. Laser flash photolysis on la provides absolute rate constants for the nucleophilic addition of various alkenes to Ph2N+. These fall in the range of 109-1010 M-1 s-1 and correlate with the oxidation potential of the alkene. From these data it is clear that the more easily oxidized the alkene the faster it will react with Ph2N+.
