Catalytic Asymmetric Construction of Spirocyclopentaneoxindoles by a Combined Ru-Catalyzed Cross-Metathesis/Double Michael Addition Sequence

Biologically important and synthetically challenging spirocyclopentaneoxindoles with four contiguous stereocenters including one spiroquaternary stereocenter have been constructed In good yields (72-87%) with excellent dlastereoselectIvity (16:1-30:1 dr) and enantloselectivity (93 -> 99% ee) by a combined Ru-catalyzed cross-metathesis/organocatalyzed asymmetric double-Michael addition sequence.