1421960-34-0Relevant academic research and scientific papers
Friedel-Crafts Hydroxyalkylation of Indoles Mediated by Trimethylsilyl Trifluoromethanesulfonate
Downey, C. Wade,Poff, Christopher D.,Nizinski, Alissa N.
, p. 10364 - 10369 (2015)
Indoles and N-alkylindoles undergo Friedel-Crafts addition to aldehydes in the presence of trimethylsilyl trifluoromethanesulfonate and a trialkylamine to produce 3-(1-silyloxyalkyl)indoles. Neutralization of the reaction mixture with pyridine followed by deprotection under basic conditions with tetrabutylammonium fluoride provides the 1:1 adduct as the free alcohol. This method prevents spontaneous conversion of the desired products to the thermodynamically favored bisindolyl(aryl)methanes, a process typically observed when indoles are reacted with aldehydes under acidic conditions.
Mechanism of the solvent-free reactions between indole derivatives and 4-nitrobenzaldehyde studied by solid-state NMR and DFT calculations
Chierotti, Michele R.,Gaglioti, Katia,Gobetto, Roberto,Barbero, Margherita,Nervi, Carlo
, p. 6732 - 6737,6 (2020/08/24)
In an effort to determine the details of the solid-state reaction mechanism of the Friedel-Crafts hydroxyalkylation between indole derivatives (indole, 1A, and N-methylindole, 1B) and an aromatic aldehyde (4-nitrobenzaldehyde), a series of solid-state NMR experiments have been performed. The reaction proceeds through a melted phase. By means of the DE pulse sequence the hydroxylic intermediate species (1H-indol-3-yl)(4- nitrophenyl)methanol (3A) and (1-methyl-1H-indol-3-yl)(4-nitrophenyl) methanol (3B) in the melt could be observed and characterized, providing evidence for elucidating the reaction mechanism. To support the experimental results, DFT calculations have been carried out showing that the first step of the reaction involving indole and nitrobenzaldehyde to give the intermediate 3A is energetically favored by 24.7 kJ mol-1, whereas the final product 3,3′-((4-nitrophenyl)methylene)bis(3a,7a- dihydro-1H-indole) (5A) is 54.8 kJ mol-1 lower in energy than the reactants. The calculated and experimental chemical shifts are also in good agreement providing further support to the proposed mechanism. This journal is
