Photoswitchable phosphines in catalysis

Photoswitchable catalysts based on phosphorus ligands have been overlooked so far, despite the growing current interest for catalysts control through external stimuli. This review surveys the current knowledge in the field, including synthetic approaches to photoswitchable phosphines and their transition metal complexes, and applications in rhodium, palladium, gold, ruthenium and copper catalysis. This survey demonstrates that both regulation of the catalytic activity and tuning of the chemo- and enantioselectivity can be achieved using irradiation as a non-invasive external stimulus. Non-catalytic uses of photoswitchable phosphines in organic synthesis are also mentioned.