Cation-Controlled Olefin Isomerization Catalysis with Palladium Pincer Complexes

Palladium(II) pincer complexes with varying amine donor substituents have been prepared and studied in olefin isomerization catalysis. Installing a macrocycle into the pincer ligand enables cation-switchable positional olefin isomerization: no reaction is observed with the catalyst alone, while in the presence of Li + salts isomerization proceeds cleanly. Mechanistic studies implicate a key role of highly electrophilic Pd centers with accessible olefin binding sites.