This Lewis acid-catalyzed electrophilic aromatic substitution allows the synthesis of alkylated products via the reaction of arenes with alkyl halides or alkenes. Since alkyl substituents activate the arene substrate, polyalkylation may occur. A valuable, two-step alternative is Friedel-Crafts Acylation followed by a carbonyl reduction.
Mechanism of the Friedel-Crafts Alkylation
Using alkenes :
Dramatic Enhancement of Catalytic Activity in an Ionic Liquid: Highly Practical Friedel-Crafts Alkenylation of Arenes with Alkynes Catalyzed by Metal Triflates
C. E. Song, D.-U. Jung, S. Y. Choung, E. J. Roh, S.-G. Lee, Angew. Chem. Int. Ed., 2004, 43, 6183-6185.
MA-Silica Gel Catalyzed Propargylation of Aromatic Compounds with Arylpropargyl Alcohols under Solvent-Free Conditions
P. Srihari, J. S. S. Reddy, S. S. Mandal, K. Satyanarayana, J. S. Yadav, Synthesis, 2008, 1853-1860.
Conversion of 2-Alkylcinnamaldehydes to 2-Alkylindanones via a Catalytic Intramolecular Friedel-Crafts Reaction
G. B. Womack, J. G. Angeles, V. E. Fanelli, C. A. Heyer, J. Org. Chem., 2007, 72, 7046-7049.