Regioselective 1,2-Diamination of Aryl-Substituted 1,3-Dienes via Axial PPh ₃ -Coordinated Dirhodium(II) Catalysis

Axial PPh₃ coordination enables the regioselective 1,2-diamination of aryl-substituted 1,3-dienes using dirhodium catalysis, employing <i>N</i>-fluorobenzenesulfonimide as the oxidant and nitrogen source. This base-free protocol proceeds via a PPh₃-stabilized dirhodium(II,III) species, facilitating efficient nitrogen radical transfer via the <i>trans</i> effect. The method features broad functional group tolerance (35 examples, up to 91% yield) and gram-scale scalability. This work highlights the potential of axial electronic tuning as a general strategy for controlling reactivity in a dirhodium-catalyzed radical reaction.