603-76-9Relevant articles and documents
Application of SBA-Pr-NH2 as a nanoporous base silica catalyst in the development of 2,2-Bis(1H-indol-3-yl)acenaphthen-1(2H)-ones syntheses
Mohammadi Ziarani,Hajiabbasi,Badiei
, p. 1649 - 1654 (2015)
One-pot reaction for the synthesis of symmetrical 2,2-bis(1H-indol-3-yl)-2H-acenaphthen-1-one is reported by condensing acenaphthenequinone and indoles in the presence of catalytic amount of amino-functionalized silica (SBA-Pr-NH2) under solvent-free conditions at 100°C. (Chemical Equation Presented).
Structure and Reactivity of Indolylmethylium Ions: Scope and Limitations in Synthetic Applications
Follet, Elsa,Berionni, Guillaume,Mayer, Peter,Mayr, Herbert
, p. 8643 - 8656 (2015)
Eight substituted aryl(indol-3-yl)methylium tetrafluoroborates 3(a-h)-BF4 and three bis(indol-3-yl)methylium tetrafluoroborates 3(i-k)-BF4 have been synthesized and characterized by NMR spectroscopy and X-ray crystallography. Their reactions with π-nucleophiles 8(a-j) (silylated enol ethers and ketene acetals) were studied kinetically using photometric monitoring at 20 °C. The resulting second-order rate constants were found to follow the correlation log k(20 °C) = sN(N + E), in which nucleophiles are characterized by the two solvent-dependent parameters N and sN, and electrophiles are characterized by one parameter, E. From the previously reported N and sN parameters of the employed nucleophiles and the measured rate constants, the electrophilicities of the indol-3-ylmethylium ions 3(a-k) were derived and used to predict potential nucleophilic reaction partners. A discrepancy between published rate constants for the reactions of morpholine and piperidine with the (2-methylindol-3-yl)phenylmethylium ion 3h and those calculated from E, N, and sN was analyzed and demonstrated to be due to a mistake of the value reported in the literature.
Potassium tert-Butoxide-Catalyzed Dehydrogenative C-H Silylation of Heteroaromatics: A Combined Experimental and Computational Mechanistic Study
Liu, Wen-Bo,Schuman, David P.,Yang, Yun-Fang,Toutov, Anton A.,Liang, Yong,Klare, Hendrik F. T.,Nesnas, Nasri,Oestreich, Martin,Blackmond, Donna G.,Virgil, Scott C.,Banerjee, Shibdas,Zare, Richard N.,Grubbs, Robert H.,Houk,Stoltz, Brian M.
, p. 6867 - 6879 (2017)
We recently reported a new method for the direct dehydrogenative C-H silylation of heteroaromatics utilizing Earth-abundant potassium tert-butoxide. Herein we report a systematic experimental and computational mechanistic investigation of this transformation. Our experimental results are consistent with a radical chain mechanism. A trialkylsilyl radical may be initially generated by homolytic cleavage of a weakened Si-H bond of a hypercoordinated silicon species as detected by IR, or by traces of oxygen which can generate a reactive peroxide by reaction with [KOt-Bu]4 as indicated by density functional theory (DFT) calculations. Radical clock and kinetic isotope experiments support a mechanism in which the C-Si bond is formed through silyl radical addition to the heterocycle followed by subsequent β-hydrogen scission. DFT calculations reveal a reasonable energy profile for a radical mechanism and support the experimentally observed regioselectivity. The silylation reaction is shown to be reversible, with an equilibrium favoring products due to the generation of H2 gas. In situ NMR experiments with deuterated substrates show that H2 is formed by a cross-dehydrogenative mechanism. The stereochemical course at the silicon center was investigated utilizing a 2H-labeled silolane probe; complete scrambling at the silicon center was observed, consistent with a number of possible radical intermediates or hypercoordinate silicates.
Oxidation of Tryptophan and N-Methylindole by N3*, Br2*-, and (SCN)2*- Radicals in Light- and Heavy-Water Solutions: A Pulse Radiolysis Study
Solar, Sonja,Getoff, Nikola,Surdhar, Parminder S.,Armstrong, David A.,Singh, Ajit
, p. 3639 - 3643 (1991)
Reactions of N3*, Br2*-, and (SCN)2*- with tryptophan (TRPH) and N-methylindole (NMI) have been investigated in H2O and D2O solutions.The main transients produced were the TRP* radical and the TRPH*+ radical cation from TRPH and the NMI*+ radical cation from NMI.Their extinction coefficients (ε) as well as the rate constants for their formation and decay were determined in the pH range 3-10.The pK of the TRPH*+ radical cation was confirmed to be 4.2 +/- 0.1.These rate constants were within experimental error, independent of pH, and the differences between the rate constants in H2O and D2O were small.On the basis of the results, it was concluded that of the two possible reactions - electron or hydrogen atom transfer - the data are more consistent with electron transfer in all cases.However, secondary acid-base reactions have an important effect on the overall redox equilibria, especially with N3*.Experimental data on these effects have also been obtained.
Synthesis of Non-Terminal Alkenyl Ethers, Alkenyl Sulfides, and N-Vinylazoles from Arylaldehydes or Diarylketones, DMSO and O, S, N-Nucleophiles
Nie, Zhiwen,Lv, Huifang,Yang, Tonglin,Su, Miaodong,Luo, Weiping,Liu, Qiang,Guo, Cancheng
supporting information, p. 1473 - 1480 (2022/04/03)
A transition-metal-free protocol for the synthesis of non-terminal alkenyl ethers, alkenyl sulfides, and N-vinylazoles from arylaldehydes or diarylketones, DMSO and O, S, N-nucleophiles has been reported. In this protocol, 24 examples of non-terminal alkenyl ethers and 28 examples of non-terminal alkenyl sulfides in 72–95% yields have been synthesized within 5 min. Moreover, 27 examples of non-terminal N-vinylazoles with 57–88% yields have also been synthesized within 2 hours. The preliminary mechanism investigations revealed that arylaldehydes or diarylketones offered a carbon atom, DMSO provided a methine and O, S, N-nucleophiles contributed one X atom for constructing C=C?X structure. (Figure presented.).
Three-component reactions of 3-arylidene-3h-indolium salts, isocyanides and amines
Nguyen, Hung M.,Golantsov, Nikita E.,Golubenkova, Alexandra S.,Rybakov, Victor B.,Voskressensky, Leonid G.
, (2021/05/26)
A multicomponent reaction of isocyanides with aryl(indol-3-yl)methylium salts and amines has been found. A series of aryl(indol-3-yl)acetimidamides was obtained in up to 96% yields. In the case of ethyl isocyanoacetate, the reaction is followed by cyclization to form 3,5-dihydro-4H-imidazol-4-one derivatives.
