Friedel-Crafts Hydroxyalkylation of Indoles Mediated by Trimethylsilyl Trifluoromethanesulfonate
C Wade Downey1, Christopher D Poff1, Alissa N Nizinski1
1University of Richmond , Gottwald Center for the Sciences, 28 Westhampton Way, Richmond, Virginia 23173, United States.
Abstract:
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.
More Related Videos
Related Concept Videos
Limitations of Friedel–Crafts Reactions
Electrophilic Aromatic Substitution: Friedel–Crafts Alkylation of Benzene
Electrophilic Aromatic Substitution: Friedel–Crafts Acylation of Benzene
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation


