Triphenylphosphine oxide promoting visible-light-driven C-C coupling via desulfurization

Triphenylphosphine oxide (TPPO) and triphenylphosphine (TPP) can form a complex in solution, promoting visible light absorption to trigger electron transfer within the complex and generate radicals. Subsequent radical reactions with thiols enable desulfurization to produce carbon radicals that react with aryl alkenes to yield new C-C bonds. Since ambient oxygen can easily oxidize TPP to TPPO, the reported method requires no explicit addition of a photocatalyst. This work highlights the promise of using TPPO as a catalytic photo-redox mediator in organic synthesis.

Automated summary

Triphenylphosphine oxide (TPPO) and triphenylphosphine (TPP) form a complex in solution, allowing visible light absorption to induce electron transfer and generate radicals. These radicals react with thiols to produce carbon radicals, which then react with aryl alkenes to form new C-C bonds. The method reported in this work does not require the explicit addition of a photocatalyst, as TPP can be easily oxidized to TPPO by ambient oxygen. This study highlights the potential of TPPO as a catalytic photo-redox mediator in organic synthesis.