Selective Photo-oxidation of C(sp ³ )–H Bonds to Aldehydes/Ketones with O ₂

The inert C(sp3)–H bonds and easy overoxidation of aldehydes make the direct oxidation of hydrocarbons to aldehydes by O2 a very difficult task. Herein, we report a photoinduced system for highly selective oxidation of the C(sp3)–H bonds to oxygenate aldehydes and ketones under ambient aerobic conditions. Mediating with 0.25 mol % hydrobromic acid (HBr) in CH3CN, the photoactivated methylarenes C–H bond shows high performance with selectivity up to 95% and a formation rate as high as 175 mmol gHBr–1 h–1 (turnover number (TON) = 29.6) toward aldehydes. The generality is demonstrated by the oxidation of toluene derivatives and aliphatic hydrocarbons. This study provides an effective, economical, and simple solution for selective aerobic oxidation of hydrocarbons to aldehydes under mild conditions with light illumination.