Enantioselective Construction of Spirocyclic Oxindolic Cyclopentanes by Palladium-Catalyzed Trimethylenemethane-[3+2]-Cycloaddition

The palladium catalyzed [3+2] trimethylenemethane (TMM) cycloaddition is an efficient method for the construction of cyclopentanes. Herein, we report a catalytic asymmetric protocol for the synthesis of spirocyclic oxindolic cyclopentanes in excellent yields and enantioselectivities, allowing for the first time the construction of up to three adjacent stereogenic centers. In this process, the chiral ligand controls the diastereo- as well as enantioselectivity.