A Unique 1,2-Acyl Migration for the Construction of Quaternary Carbon by Visible Light Irradiation of Platinum(II) Polypyridyl Complex and Molecular Oxygen

A unique 1,2-acyl migration for the construction of quaternary carbon in a one-pot reaction under visible light is described. By irradiating a platinum(II) polypyridyl complex with visible light, enamine 1 is able to react with alcohol 2 to yield compound 3 featuring a quaternary carbon via 1,2-acyl migration and concurrent esterification. Studies on the mechanism reveal that the platinum(II) complex is able to generate singlet oxygen (O-1(2)) that is responsible for this unprecedented intramolecular 1,2-acyl migration transformation.