Room-TemperatureLigationof Iminophosphoranes with <i>gem</i>-Difluoroalkenes

Ligation reactions that proceed at room temperature under aqueous conditions and without catalysts are in high demand, including bioorthogonal reactions. We report a mild amide-ligation reaction of iminophosphoranes with <i>gem</i>-difluoroalkenes. Through experimental and theoretical analyses of intermolecular and intramolecular amidation reactions, we found that the Staudinger–Bertozzi ligation-type reaction of iminophosphoranes with <i>gem</i>-difluoroalkenes is an excellent reaction that proceeds rapidly at room temperature in an aqueous solvent.