Scalable Flow Electrosynthesis of Iminophosphoranes

A scalable electrochemical process to synthesize iminophosphorane ligands is reported. The application of these iminophosphoranes was recently reported in Ni-catalyzed cross-electrophile and C–N cross-couplings. The use of parallel plate flow electrochemical reactors enables the synthesis of these iminophosphorane ligands on a multigram scale, with selected examples reported on up to 0.6 kg scale. Direct crystallization from the end of reaction mixture for selected ligands provides facile isolation processes. This article also details improvements in our electrochemical capabilities across scales, including addressing material compatibility issues, increasing accessible range of flow rates, and integration of process analytical technology tools.