Cl₂ ⋅^- Mediates Direct and Selective Conversion of Inert C(sp³ )-H Bonds into Aldehydes/Ketones

Developing new reactive pathway to activate inert C(sp³ )-H bonds for valuable oxygenated products remains a challenge. We prepared a series of triazine conjugated organic polymers to photoactivate C-H into aldehyde/ketone via O₂ →H₂ O₂ →⋅OH→Cl⋅→Cl₂ ⋅^- . Experiment results showed Cl₂ ⋅^- could successively activate C(sp³ )-H more effectively than Cl⋅ to generate unstable dichlorinated intermediates, increasing the kinetic rate ratio of dichlorination to monochlorination by a factor of 2,000 and thus breaking traditional dichlorination kinetic constraints. These active intermediates were hydrolyzed into aldehydes or ketones easily, when compared with typical stable dichlorinated complexes, avoiding chlorinated by-product generation. Moreover, an integrated two-phase system in an acid solution strengthened the Cl₂ ⋅^- mediated process and inhibited product overoxidation, where the conversion rate of toluene reached 16.94 mmol/g/h and the selectivity of benzaldehyde was 99.5 %. This work presents a facile and efficient approach for selective conversion of inert C(sp³ )-H bonds using Cl₂ ⋅^- .