Cl ⋅ Mediates Direct and Selective Conversion of Inert C(sp )-H Bonds into Aldehydes/Ketones.

Developing new reactive pathway to activate inert C(sp )-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 O →H O →⋅OH→Cl⋅→Cl ⋅ . Experiment results showed Cl ⋅ could successively activate C(sp )-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 Cl ⋅ 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(sp )-H bonds using Cl ⋅ .