Alkylation of heteroarenes by using aldehydes is a direct approach to increase molecular complexity, which however often involves the use of stochiometric oxidant, strong acid, and high temperature. This study concerns an energy-efficient electrochemical alkylation of heteroarenes by using aldehydes undermildconditions without mediators. Interestingly, the graphite anode can trigger aldehyde cationic
A bismuth(III) triflate catalyzed three-component synthesis of α-substituted amides starting from amides, aldehydes, and (hetero)arenes is reported. The reaction has a broad substrate scope, encompassing formaldehyde as well as aryl and alkyl aldehydes. Low catalyst loadings are required, and water is formed as the only side product. The scope and limitation of this method will be discussed.
an efficient catalyst for a double Friedel–Crafts reaction of various heteroarenes, i.e. 2-methylfuran, 2-ethylfuran, 2-methylthiophene, pyrrole, N-methylpyrrole and indole, using aldehydes as alkylating agents under “open-flask” conditions with toluene or water as the reaction media. In the presence of 10 mol% iodine in toluene at room temperature, both aliphatic and aromatic aldehydes reacted smoothly