Photoelectrochemical Iron-Catalyzed Fluoroalkylative Azidation of Alkenes with Fluoroalkyl Carboxylic Acids

Vicinal fluoroalkylated amines represent a privileged scaffold in bioactive molecules and therapeutic agents. The development of a general and practical strategy for the fluoroalkylative amination of alkenes using readily available fluoroalkylating reagents has remained a significant challenge. Here, we describe an earth-abundant iron-catalyzed protocol for the fluoroalkylative azidation of unactivated alkenes, employing inexpensive commercial fluoroalkyl carboxylic acids directly as fluoroalkyl sources. This method operates without external chemical oxidants or pre-functionalization steps. A wide range of simple alkenes and fluoroalkyl carboxylic acids are compatible, affording synthetically versatile fluoroalkylated azides in good efficiency. Notably, the difluoromethylative azidation was demonstrated on a multi-gram scale using a catalytic amount of electrolyte and minimized solvent, overcoming previous limitations in scope, scalability, and practicality. The obtained products can be smoothly transformed into diverse fluoroalkylated amines and other nitrogen-containing compounds. Mechanistic investigations, including cyclic voltammetry and control experiments, reveal that the mild anodic potential combined with the acidic conditions is crucial for the success of this protocol.