Abstract An easy one-step synthesis of 3,4-diarylsydnones from 3-arylsydnones and arylboronic acids by Pd-catalyzed C–H bond activation is described. An easy one-step synthesis of 3,4-diarylsydnones from 3-arylsydnones and arylboronic acids by Pd-catalyzed C–H bond activation is described.