Ru(II)-Catalyzed C-H activation and annulation of salicylaldehydes with monosubstituted and disubstituted alkynes

The Ru(II)-catalyzed C-H activation and annulation reaction of salicylaldehydes and disubstituted alkynes affords chromones in high yields. This reaction also works with terminal alkynes and tolerates a wide range of sensitive functional groups. The selectivity pattern of this Ru(II)-catalyzed annulation reaction is different from the known Au(I), Rh(III)-catalyzed annulation reactions of salicylaldehydes and terminal alkynes.