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 diastereoselectivity (16:1→30:1 dr) and enantioselectivity (93→99% ee) by a combined Ru-catalyzed cross-metathesis/organocatalyzed asymmetric double-Michael addition sequence.

Highly enantioselective one-pot synthesis of spirocyclopentaneoxindoles containing the oxime group by organocatalyzed Michael addition/ISOC/fragmentation sequence.

A highly diastereo- and enantioselective organocatalytic protocol for the synthesis of biologically important spirocyclopentaneoxindoles containing the oxime functional group from easily accessible 3-allyl-substituted oxindoles and nitroolefins has been developed by a one-pot Michael addition/ISOC/fragmentation sequence.