Photocatalyzed Dicyanation of Alkenes Enabled by Phosphorus Radical Cation Addition.

While notable progress has been made in alkene cyanation for the synthesis of alkyl nitriles, catalytic strategies enabling the direct dicyanation of simple alkenes remain relatively under-explored. In this study, we introduce a synergistic phosphine-photoredox catalytic system that facilitates the direct dicyanation of styrenes using TMSCN in the presence of oxidant. This approach utilizes a phosphorus radical cation to initiate an oxidative radical-polar crossover with alkenes, followed by sequential nucleophilic cyanation. This protocol allows for the efficient synthesis of alkyl 1,2-dinitriles from alkenes under mild conditions. Notably, the method exhibits broad substrate scope and commendable efficiency, serving as a valuable complement to existing cyanation methodologies. The synthetic utility of the dinitrile products is further demonstrated through diverse derivatization reactions, highlighting their applicability in constructing nitrogen-rich molecular architectures. Mechanistic studies provide further insight into the reaction pathway and underscore the potential of phosphorus radical cations in alkene functionalization.