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

Photo-release of triphenylphosphine from a sulfonamide azobenzene ruthenium-arene complex was exploited to activate (PdCl2)-Cl-II into Pd-0 catalyst, for the photo-initiation of Sonogashira cross-coupling. The transformation was initiated on demand - by using simple white LED strip lights - with a high temporal response and the ability to control reaction rate by changing the irradiation time. Various substrates were successfully applied to this photo-initiated cross-coupling, thus illustrating the wide functional-group tolerance of our photo-caged catalyst activator, without any need for sophisticated photochemistry apparatus.

Automated summary

In this study, a sulfonamide azobenzene ruthenium-arene complex was used to release triphenylphosphine, which activated (PdCl2)-Cl-II into Pd-0 catalyst for the photo-initiation of Sonogashira cross-coupling. Simple white LED strip lights were used to initiate the transformation, providing a high temporal response and the ability to control reaction rate by changing the irradiation time. Various substrates were successfully applied to this photo-initiated cross-coupling, demonstrating the wide functional-group tolerance of the photo-caged catalyst activator without the need for sophisticated photochemistry apparatus.