Ruthenium-catalyzed (spiro)annulation of N-aryl-2,3-dihydrophthalazine-1,4-diones with quinones to access pentacyclic spiro-indazolones and fused-cinnolines

The concise syntheses of spiro-indazolones and fused-cinnolines by Ru( ii )-catalyzed [4 + 1] and [4 + 2] oxidative coupling between N -aryl-2,3-dihydrophthalazine-1,4-diones and 1,4-benzoquinones.