Asymmetric Synthesis of 3‐Allyloxindoles and 3‐Allenyloxindoles by Scandium(III)‐Catalyzed Claisen Rearrangement Reactions

Scandium‐catalyzed asymmetric Claisen rearrangement reactions of 2‐allyloxyindoles and 2‐propargyloxyindoles provide a novel approach to diverse 3‐allyloxindoles and 3‐allenyloxindoles in excellent yields (up to 99%) and enantioselectivity (up to 99% ee ) under mild reaction conditions. The scandium catalyst was derived from Sc(OTf )₃ and Pybox ligand.