Recyclable and reusable<i>n</i>-Bu<sub>4</sub>NBF<sub>4</sub>/PEG-400/H<sub>2</sub>O system for electrochemical C-3 formylation of indoles with Me<sub>3</sub>N as a carbonyl source
A safe, practical and eco-friendly electrochemical methodology for the synthesis of 3-formylated indoles has been developed by the utilization of Me3N as a novel formylating reagent. Stoichiometric oxidants, metal catalysts, and activating agents were avoided in this method, and an aqueous biphasic system of n-Bu4NBF4/PEG-400/H2O was used as a recyclable and reusable reaction medium, which made this