Photocatalytic Aerobic Oxysulfonylation of Alkynes to Access β-Keto Sulfones Catalyzed by OVs-N-Nb2O5

Herein, we report a novel heterogeneous photocatalyst for radical-mediated oxidative oxysulfonylation of alkynes to beta-keto sulfones under environmentally benign conditions. The oxygen vacancy-rich semiconductor Nb2O5 (labeled as OVs-N-Nb2O5) could efficiently catalyze a wide range of alkynes, especially for those bearing electron-deficient substituents or internal alkynes, to their corresponding beta-keto sulfones in good to high yields with good tolerance of diverse functional groups under visible-light illumination. The late-stage modification of steroidal compounds and synthesis of bioactive molecules were also achieved via this procedure, highlighting its potential for practical applications. Meanwhile, the photocatalyst OVs-N-Nb2O5 showed outstanding catalytic stability for successive recycles without appreciable loss in activity and selectivity. The critical role of oxygen vacancies on improving reaction activity and selectivity was clearly disclosed via control experiments and theoretical calculation.