Metal-free Photocatalytic Aerobic Oxidative Cleavage of C−C Bonds in 1,2-Diols

Graphical Oxidative cleavage : A heterogeneous metal-free photocatalytic system is developed for oxidative cleavage of C−C bonds in 1,2-diols at mild conditions (visible light, room temperature, no base, O 2 balloon). The reaction mechanism is studied through a series of control experiments and DFT calculations. In addition, the catalytic system has a broad substrate scope, including aliphatic, benzylic, alkenyl 1,2-diols, and α-hydroxy acids such as lactic acid. The preparation of carbonyl compounds by the aerobic oxidative cleavage of C−C bonds in 1,2-diols under mild reaction conditions is a very significant reaction and is widely employed in various scenarios. Avoiding the use of harmful stoichiometric oxidants and adopting a greener chemical process remain a challenge for this reaction to date. In this manuscript, a heterogeneous metal-free photocatalytic strategy without any additive was developed for aerobic oxidative cleavage of C−C bonds in 1,2-diols at ambient conditions with visible light. The reaction mechanism was further studied through a series of control experiments and density functional theory (DFT) calculations. In addition, the catalytic system showed a broad substrates scope, including aliphatic (linear or cyclic) 1,2-diols, benzylic, alkenyl 1,2-diols, and α-hydroxy acids (such as lactic acid). Thus, this strategy could serve as a method for the transformation of 1,2-diols to corresponding carbonyl compounds by the aerobic oxidative cleavage of C−C bonds.