Cl-2(center dot-) Mediates Direct and Selective Conversion of Inert C(sp(3))-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!H2O2!*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 *.

Automated summary

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!H2O2!*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 *.