Xi:Irritant;
83-34-1Relevant articles and documents
Vapor phase methylation of indole over nanocrystalline Cd1-xCrxFe2O4 (x = 0, 0.25, 0.5, 0.75 and 1.0) ferrospinels
Kadian,Siwach,Gupta,Duhan
, p. 1474 - 1478 (2016)
Vapor phase methylation of indole has been carried out over nanocrystalline Cd1-xCrxFe2O4 (x = 0, 0.25, 0.5, 0.75 and 1.0) ferrospinels in a fixed bed down-flow reactor. Catalyst characterization was performed by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy with EDX, BET surface area and temperature programmed ammonia-desorption method. Product selectivity is shown to be strongly influenced by acidic properties of the catalyst. A maximum yield of 64.29 % of 3-methyl indole with 91.46 % selectivity at 70.3 % indole conversion was obtained under optimized reaction conditions.
A remarkable mechanistic dichotomy in the acid-catalysed decomposition of the N- And C-adducts of indolide anions with 1,3,5-trinitrobenzene
Sepulcri, Patricia,Goumont, Regis,Terrier, Francois,Buncel, Erwin
, p. 2241 - 2243 (1996)
Decomposition of the N- and C-adducts of indolide anions with 1,3,5-trinitrobenzene is subject to specific acid-catalysis in the former case and general-acid-catalysis in the latter through an SEAr process.
Catalytic signal amplification using a heck reaction. An example in the fluorescence sensing of Cu(II)
Wu, Qiaoyin,Anslyn, Eric V.
, p. 14682 - 14683 (2004)
Catalytic signal enhancement using an organometallic reaction is demonstrated. The reactivity of a Heck cross-coupling reaction that creates a fluorophore is modulated by the addition of a polyazacyclam inhibitor. The inhibitor will complex with Cu(II), which restores the activity of the Pd(II). The addition of Cu(II) therefore leads to the generation of fluorescence, thereby creating a very sensitive assay for Cu(II). The rate of the Heck reaction is followed by monitoring emission as a function of time. The rate is proportional to the Cu(II) concentration and correlates to the affinity of the inhibitor to various metals. This strategy represents a general technique that can be exploited with other catalytic organometallic reactions. Copyright
Ring-methylation of pyrrole and indole using supercritical methanol
Kishida, Nobuhiro,Kamitanaka, Takashi,Fusayasu, Masafumi,Sunamura, Takashi,Matsuda, Tomoko,Osawa, Tsutomu,Harada, Tadao
, p. 5059 - 5064 (2010)
The ring-methylation of pyrrole or indole using supercritical methanol proceeded at 623 K without the further addition of catalysts. Pyrrole produced a mixture of unreacted pyrrole and mono-, di-, tri-, and tetra-methylpyrroles at the reaction time of 8 h. On the other hand, indole was selectively methylated at the C3 position to afford 3-methylindole in 79% yield at the reaction time of 5 h. The ring-methylation of indole using supercritical methanol was claimed to proceed via (1H-indol-3-yl)methanol. The conversion of indole to (1H-indol-3-yl)methanol would be achieved by the electrophilic aromatic substitution between the indol-1-ide (indole anion) and H2C +-OH. The (1H-indol-3-yl)methanol must be reduced to 3-methylindole in the presence of supercritical methanol.
Efficient synthesis of 3-methylindole using biomass-derived glycerol and aniline over ZnO and CeO2 modified Ag/SBA-15 catalysts
Gao, Yining,Lin, Shuyi,Qu, Yi,Shi, Lei
, (2020)
An efficient mesoporous catalyst of Ag/SBA-15 modified with ZnO and CeO2 was successfully constructed with the purpose of efficiently synthesizing 3-methylindole by biomass-derived glycerol and aniline, which up to 62% yield and 75% selectivity for 3-methylindole were achieved when Ag loading was 1.00 mmol/g?1, ZnO or CeO2 content was 1.00 or 0.05 mmol/g?1, respectively. And only 3% yield decreased when the catalyst was circulated five times. The characterizations researches on N2 physical adsorption, Fourier transform infrared (FT-IR), scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDX), temperature programmed reduction of hydrogen (H2-TPR), X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature programmed desorption (TPD) of NH3 and CO2, thermogravimetric and differential thermal analysis (TG-DTA) indicated that adding the promoter of ZnO to Ag/SBA-15 increased the dispersion of the silver particles significantly and controlled the aggregation of Ag nanoparticles during the reaction remarkably because doping ZnO greatly increased the polarity of the composite carrier SBA–15–ZnO and brought about the interaction between Ag and carrier enhanced. CeO2 could promote the reduction of Ag2O and suppress the formation of carbon deposition effectively. In addition, doping ZnO and CeO2 increased the number of the weak-acid centers of the SBA-15 supported Ag-based catalyst observably, thereby the catalyst of Ag/SBA-15-ZnO-–ZnO–CeO2 acquired a good selectivity. Moreover, the reaction pathway for 3-methylindole synthesis by biomass-derived glycerol and aniline was probed in depth and a reasonable route was proposed.
Highly selective synthesis of 3-methylindole from glycerol and aniline over Cu/NaY modified by K2O
Cui, Yan-Xi,Sun, Li-Dong,Sun, Qi,Shi, Lei
, p. 1127 - 1129 (2013)
The vapor-phase synthesis of 3-methylindole from glycerol and aniline over Cu/NaY modified by K2O was investigated. The catalysts were characterized by X-ray diffraction (XRD) and the temperature-programmed desorption of ammonia (NH3-TPD). The effect of the reaction temperature on the activity and selectivity of Cu/NaY-K2O catalyst was also investigated. The results indicated that the addition of K2O to Cu/NaY increased the selectivity of the catalyst remarkably because the amount of middle-strong acid sites decreased clearly. The decrease of the reaction temperature was beneficial for the increase of 3-methylindole selectivity. Over Cu/NaY-K2O, the selectivity of 3-methylindole reached 75% and the yield of the target product was up to 47% at 220 C. A probable catalytic mechanism for the synthesis of 3-methylindole from glycerol and aniline was proposed.
Interrupted Intramolecular Hydroaminomethylation of N-Protected-2-vinyl Anilines: Novel Access to 3-Substitued Indoles or Indoline-2-ols
Daran, Jean-Claude,García-Ríos, Perla H.,Gouygou, Maryse,Hochberger-Roa, Frank,López-Cortés, José G.,Ortega-Alfaro, M. Carmen,Urrutigo?ty, Martine
, (2022/02/11)
A new synthetic alternative to the synthesis of 3-methyl indoles and 3-methyl indoline-2-ols with an excellent atomic economy is presented in this study. It is demonstrated that the intramolecular interrupted hydroaminomethylation (HAM) reaction is a powerful tool for the formation of these compounds, which exhibit wide-ranging biological activity. Several N-Protected-2-vinyl anilines were synthesized and involved in the reaction producing the corresponding 3-methylindole or 3-methyl indoline-2-ol depending on the nature of the N-protecting groups.
Metal-Organic Framework-Confined Single-Site Base-Metal Catalyst for Chemoselective Hydrodeoxygenation of Carbonyls and Alcohols
Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Manna, Kuntal
supporting information, p. 9029 - 9039 (2021/06/28)
Chemoselective deoxygenation of carbonyls and alcohols using hydrogen by heterogeneous base-metal catalysts is crucial for the sustainable production of fine chemicals and biofuels. We report an aluminum metal-organic framework (DUT-5) node support cobalt(II) hydride, which is a highly chemoselective and recyclable heterogeneous catalyst for deoxygenation of a range of aromatic and aliphatic ketones, aldehydes, and primary and secondary alcohols, including biomass-derived substrates under 1 bar H2. The single-site cobalt catalyst (DUT-5-CoH) was easily prepared by postsynthetic metalation of the secondary building units (SBUs) of DUT-5 with CoCl2 followed by the reaction of NaEt3BH. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy (XANES) indicated the presence of CoII and AlIII centers in DUT-5-CoH and DUT-5-Co after catalysis. The coordination environment of the cobalt center of DUT-5-Co before and after catalysis was established by extended X-ray fine structure spectroscopy (EXAFS) and density functional theory. The kinetic and computational data suggest reversible carbonyl coordination to cobalt preceding the turnover-limiting step, which involves 1,2-insertion of the coordinated carbonyl into the cobalt-hydride bond. The unique coordination environment of the cobalt ion ligated by oxo-nodes within the porous framework and the rate independency on the pressure of H2 allow the deoxygenation reactions chemoselectively under ambient hydrogen pressure.
Ir(iii)-Catalysed electrooxidative intramolecular dehydrogenative C-H/N-H coupling for the synthesis of N-H indoles
Chang, Sukbok,Kim, Dongwook,Kim, Youyoung
supporting information, p. 12309 - 12312 (2021/12/07)
Herein, an iridium(iii)-catalysed electrooxidative intramolecular dehydrogenative C-H/N-H coupling of unprotected 2-alkenyl anilines is described. The developed method allows the synthesis of a variety of 3-substituted N-H indole scaffolds under undivided electrolytic conditions. Mechanistic studies suggest that the reaction proceeds through the electro-oxidation induced reductive elimination pathway.
