Remote N‑Substituent‑Tuned Dichotomous Diradical Scission Enables Photocatalytic Divergent Rearrangement of Allylic Aminophosphines

Abstract Organophosphorus compounds are widely prevalent in pharmaceuticals, agrochemicals, and functional materials, and phosphoranyl radicals represent a versatile platform for the construction of these valuable molecules. Although the selectivity of α- and β-scission dictates the reaction outcomes of phosphoranyl radical transformations, established strategies for tuning such fragmentation are confined to monoradical systems and rely on local structural modification at the phosphorus center. Herein, we realize remote N-substituent-controlled switching between α- and β-scission pathways of phosphorus–carbon triplet diradicals and apply this concept in a visible-light energy transfer photocatalytic divergent rearrangement of allylic aminophosphines to access two structurally significant organophosphorus skeletons. Computational studies reveal that the electronic properties of N-substituents govern the geometries of phosphoranyl radicals: N-alkoxy substituents favour α-scission, whereas N-sulfonyl substituents promote β-scission. This work provides new mechanistic insights into heteroatom diradical reactivity and broadens the available tools for divergent synthesis of organophosphorus compounds.