Anodically Triggered Aldehyde Cation Autocatalysis for Alkylation of Heteroarenes.

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 under mild conditions without mediators. Interestingly, the graphite anode can trigger aldehyde cationic species, which act as the effective autocatalysts to react with a range of heteroarenes to produce the corresponding products with excellent regioselectivity and in high yields. Compared to the traditional electro-synthesis approaches, this electro-triggered reaction provides an electricity-saving and eco-friendly route to high-value chemicals.