Indirect Electrocatalysis for Coupling of Amines to Imines by Robust Polyoxometalate Based Foam

ABSTRACT The application of polyoxometalates (POMs) toward electrocatalysis is a thrilling and very dynamic yet challenging research field owing to their intrinsic fragility and poor processability. For the lacunary POMs (TBA 4 H[PW 11 CuO 39 ], PW 11 Cu) crystals, they have high solubility in polar solvents and very low surface areas, which impede their applications as heterogeneous electrocatalysts. In this study, copper substituted PW 11 Cu have been shaped on the commercial carboxymethylcellulose (CMC) by a facile freeze‐drying strategy, forming the PW 11 Cu‐based CMC foam materials, PW 11 Cu@CMC. Importantly, thus obtained PW 11 Cu@CMC with remarkable catalytic activity and robustness for at least eight cycles can serve as powerful heterogeneous electrocatalyst for coupling of C═N bonds to synthesize a series of imine compounds with excellent yields (99%). We used foam material as electrocatalyst for ease in scale‐up production (∼1 g in a batch experiment) of a series of imine compounds. The reaction operates under room‐temperature and normal pressure in the absence of precious metal catalyst, precious metal electrode, acids and bases. It might inaugurate a new avenue to apply PW 11 Cu‐based foams for electrocatalytic application in organic synthesis.