Visible‐Light‐Initiated Palladium‐Catalyzed Cross‐coupling by PPh3 Uncaging from an Azobenzene Ruthenium–Arene Complex

Triphenylphosphine photo-release from a sulfonamide azobenzene ruthenium-arene complex was exploited to activate Pd(II)Cl2 into Pd(0) catalyst, for the photo-initiation of Sonogashira cross-couplings. The transformation was initiated on demand – using simple white LED strip lights – with a high-temporal response and the ability to control reaction rate according to irradiation time. Various substrates were successfully applied to this photo-initiated cross-coupling, illustrating the wide functional group tolerance of our photo-caged catalyst activator, without a need for sophisticated photochemistry apparatus.