Ruthenium(II)-Catalyzed (4+2) Annulative Difunctionalization of Non-conjugated Alkenyl Amides with Hydroxamic Acid Esters.

Ru(II)-catalyzed C-H bond activation strategy has been capitalized through a (4+2) annulative difunctionalization of non-conjugated alkenyl amides. Under mild conditions, a broad range of (hetero)aromatic amides embedded with NH-OMe unit as an internal oxidant produced high-value dihydroisoquinolinone scaffolds in good to excellent yields. This heteroannulation is also effective with acrylamides to dispense dihydro-2-pyridones and accommodates bioactive scaffolds such as tocopherol, estrone, and amino acids.