Friedel crafts alkylation: Learn the key differences

Learn the key differences, mechanisms, and applications of Friedel-Crafts alkylation and acylation for aromatic compounds. Simple explanations and solved examples for students. Mechanism of Friedel-Crafts Alkylation Reaction of a Benzene The mechanism of the Friedel-Crafts Alkylation Reaction of benzene is discussed in the steps mentioned below: Step 1: The formation of an electrophilic carbocation is the first step. In this step, alkyl halide reacts with the Lewis acid such as anhydrous aluminium chloride or ferric chloride which results in the generation of electrophilic carbocation. A Friedel-Crafts alkylation reaction is an electrophilic aromatic substitution reaction in which a carbocation is attacked by a pi bond from an aromatic ring with the net result that one of the aromatic protons is replaced by an alkyl group. Friedel-Crafts Alkylation 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.