Photoinduced Vitamin B-Catalysis for Deprotection of (Allyloxy)arenes.

Vitamin B is a natural cobalt complex that, while reduced to the "supernucleophilic" Co(I) form, can easily react with electrophiles via an S2 mechanism. It is also shown to react via an S2' mechanism with allylic compounds allowing for photochemical deprotection of (allyloxy)arenes. A sustainable alternative to commonly used noble metal-catalyzed deprotection reactions is presented.