Visible-Light-Mediated Three-Component Decarboxylative Coupling Reactions for the Synthesis of 4‑Alkylpyridines

4-Alkylation of pyridines has been achieved by a photocatalyzed
three-component reaction of an olefin, an aryloxyacetic acid, and
cyanopyridine using Ir[dF(CF3)ppy]2(dtbbpy)PF6 as a photocatalyst. In this way, a new type of 4-alkylpyridines
bearing aryl and aryloxy substituents on the phenyl was accessed with
potential pharmaceutical value. In addition to mild reaction conditions,
the method has several other advantages, including a multicomponent
one-pot protocol, good functional group tolerance, and easy amplification
of the reaction scale. The reaction mechanism has been clarified by
control experiments and computation of the reaction energy profile.