Efficient α‑Alkylation of Arylacetonitriles with Secondary Alcohols Catalyzed by a Phosphine-Free Air-Stable Iridium(III) Complex

A well-defined and readily available
air-stable dimeric iridium­(III)
complex catalyzed α-alkylation of arylacetonitriles using secondary
alcohols with the liberation of water as the only byproduct is reported.
The α-alkylations were efficiently performed at 120 °C
under solvent-free conditions with very low (0.1–0.01 mol %)
catalyst loading. Various secondary alcohols including cyclic and
acyclic alcohols and a wide variety of arylacetonitriles bearing different
functional groups were converted into the corresponding α-alkylated
products in good yields. Mechanistic study revealed that the reaction
proceeds via alcohol activation by metal–ligand cooperation
with the formation of reactive iridium-hydride species.