2025 Theses Doctoral

Metallaphotoredox Catalysis from Red to Blue: New Methods in C–N and C–C Cross-Coupling

Goldschmid, Samantha Lindsay

Dual transition metal and photoredox catalysis is a powerful tool that harnesses visible light to enable novel chemical transformations. The conferral of open-shell processes facilitated by photoredox catalysis to the modular bond-forming capabilities of transition metal cross-coupling has led to the development of many new synthetic methods that couple unactivated, bench-stable feedstock chemicals to form value-added products. The Rovis group has previously reported the use of deep red and near infrared light in photoredox catalysis.

Herein, we report the use of an osmium-based photosensitizer in combination with deep red light to realize a dual nickel-catalyzed C–N cross-coupling method with batch-scalability, greater functional group tolerance, and decreased deleterious side-reactivity. Additionally, we report the synthesis and characterization of a library of osmium-based photocatalysts to facilitate the adoption of low energy photoredox catalysis. Finally, we leverage the unique properties of copper and iridium-based photoredox catalysis with blue light to enable the cross-coupling of tertiary benzylic radicals to furnish all-carbon diaryl quaternary centers.