Selective Electrochemical Dibromination of Terpenes and Naturally Derived Olefins

A simple electrochemical protocol is established for the selective alkene dibromination of naturally derived olefins, such as terpenes. The use of hazardous Br-2 or its analogues have been elegantly avoided by employing readily available, inexpensive, and harmless sodium bromide with a dual role as reagent and supporting electrolyte in combination with sustainable carbon-based electrodes. This electrochemical protocol provides the desired products with good to excellent yields up to 82% with 10 examples. Scalability has been proved by a 5-fold scale-up. Notably, higher yields and selectivity were achieved in comparison to conventional bromination by Br-2 and DMSO/HBr system and the dibrominated compound was eligible for further functionalization, such as cyanation according to the Kolbe nitrile synthesis protocol.