Decatungstate-mediated solar photooxidative cleavage of C=C bonds using air as an oxidant in water

With the increasing attention for green chemistry and sustainable development, there has been much interest in searching for greener methods and sources in organic synthesis. However, toxic additives or solvents are inevitably involved in most organic transformations. Herein, we first report the combination of direct utilization of solar energy, air as the oxidant and water as the solvent for the selective cleavage of C = C double bonds in aryl olefins. Various alpha-methyl styrenes, diaryl alkenes as well as terminal styrenes are well tolerated in this green and sustainable strategy and furnished the desired carbonyl products in satisfactory yields. Like heterogeneous catalysis, this homogeneous catalytic system could also be reused and it retains good activity even after repeating three times. Mechanism investigations indicated that both O-2(-) and O-1(2) were involved in the reaction. Based on these results, two possible mechanisms, including the electron transfer pathway and the energy transfer pathway, were proposed.

Automated summary

The study presents a green and sustainable strategy for the selective cleavage of C = C double bonds in aryl olefins using solar energy, air as the oxidant, and water as the solvent. Various aryl olefins showed good tolerance in this method and yielded the desired carbonyl products in satisfactory yields. The homogeneous catalytic system used in the reaction could also be reused and retained good activity even after repeating three times, with involvement of O-2(-) and O-1(2) in the reaction and proposed mechanisms involving electron transfer and energy transfer pathways based on mechanism investigations.