741709-22-8Relevant academic research and scientific papers
CNT-CuO catalyzed C–N bond formation for N-arylation of 2-phenylindoles
Lim, Jeongah,Kim, Ji Dang,Choi, Hyun Chul,Lee, Sunwoo
supporting information, (2019/10/14)
Carbon nanotube–copper oxide (CNT–CuO) nanocomposites were prepared by depositing CuO nanoparticles onto functionalized CNT surfaces. The structure and elemental content of CNT–CuO were characterized using transmission electron microscopy, X-ray diffraction, and Auger electron spectroscopy. The prepared CNT-CuO was subsequently employed as a catalyst for the coupling reaction of 2-phenylindole with aryl iodides to provide the desired N-aryl 2-phenylindoles in good yields.
Palladium-catalyzed annulation of diarylamines with olefins through C-H activation: Direct access to N-arylindoles
Sharma, Upendra,Kancherla, Rajesh,Naveen, Togati,Agasti, Soumitra,Maiti, Debabrata
supporting information, p. 11895 - 11899 (2015/01/09)
A palladium-catalyzed dehydrogenative coupling between diarylamines and olefins has been discovered for the synthesis of substituted indoles. This intermolecular annulation approach incorporates readily available olefins for the first time and obviates the need of any additional directing group. An ortho palladation, olefin coordination, and β-migratory insertion sequence has been proposed for the generation of olefinated intermediate, which is found to produce the expected indole moiety.
Indium-catalyzed annulation of 2-aryl- and 2-heteroarylindoles with propargyl ethers: Concise synthesis and photophysical properties of diverse aryl- and heteroaryl-annulated[a]carbazoles
Tsuchimoto, Teruhisa,Matsubayashi, Hiromichi,Kaneko, Masayoshi,Nagase, Yuta,Miyamura, Takuhiro,Shirakawa, Eiji
supporting information; experimental part, p. 15823 - 15835 (2009/05/16)
Treatment of 2-aryl- and 2-heteroarylindoles with propargyl ethers in the presence of a catalytic amount of indium nonafluorobutanesulfonate [In(ONf) 3] gave aryl- and heteroaryl-annulated[a]carbazoles in good yields. The synthetically attractive feature is reflected by its applicability to a wide range of 2-aryl-and 2-heteroarylindoles. In the annulation reaction, propargyl ethers act as C3 sources (HC≡C-CH2OR). Among these, two carbon atoms are incorporated into the product as members of a newly constructed aromatic ring and the remaining carbon atom forms a methyl group on the aromatic ring, where the methyl group is always located next to the C3 position of the indole nucleus. The methyl group can be easily removed through SeO2 oxidation followed by decarbonylation with RhCl(CO)(PPh3) 2-Ph2P(CH2)3PPh2 as a catalyst. The new annulation strategy is applicable also to symmetrical dimers such as bithiophene and bifuran derivatives. Mechanistic studies suggest that the first step is addition reaction initiated by regioselective nucleophilic attack of the C3 of 2-aryl- and 2-heteroarylindoles to the internal carbon atom of the C≡C bond in propargyl ethers. The next stage is ring-closing S N2 process kicking out the alkoxy group and then aromatization via a 1,3-hydrogen shift is the final step. The two carbon-carbon bond-forming reactions achieved in one-pot contribute largely to the reduction in the number of steps for the synthesis of aryl- and heteroaryl-annulated[a]carbazoles. Furthermore, utilization of the Fischer indole synthesis for efficient supply of the substrates, 2-aryl- and 2-heteroarylindoles, is another important factor shortening the overall process. The development of the annulation with a wide substrate scope provided a unique opportunity to evaluate photophysical properties of a series of aryl- and heteroaryl-annulated[a]-carbazoles. Almost all the compounds evaluated in this study were found to emit purple to green light in the visible region. Some interesting structure-property correlations are also described.
Direct C-H bond arylation: Selective palladium-catalyzed C2-arylation of N-substituted indoles
Lane, Benjamin S.,Sames, Dalibor
, p. 2897 - 2900 (2007/10/03)
(Equation Presented) We present a new, practical method by which N-substituted indoles may be selectively arylated in the C2-position with good yields, low catalyst loadings, and a high degree of functional group tolerance. Our investigation found that two competitive processes, namely, the desired cross-coupling and biphenyl formation, were operative in this reaction. A simple kinetic model was formulated that proved to be instructive and provided useful guidelines for reaction optimization; the approach described within may prove to be useful in other catalytic cross-coupling processes.
