Carbenium ion formation by fragmentation of electrochemically generated oxonium ions ; Friedel–Crafts Alkylation with Carbenium Ions Generated by Electrochemical Oxidation of Stannylmethyl Ethers ; Intramolecular Friedel‒Crafts alkylation by electrochemical carbenium ion generation ; Torii-Type Electrosynthesis of α,β-Unsaturated Esters from Furfurylated Ethylene Glycols and Amino Alcohols.