Diastereo- and Enantioselective Construction of Oxindole-Fused Spirotetrahydrofuran Scaffolds through Palladium-Catalyzed Asymmetric [3+2] Cycloaddition of Vinyl Cyclopropanes and Isatins

A novel asymmetric formal [3+2] cycloaddition of vinyl cyclopropanes and isatins in the presence of Pd2(dba)3 and the chiral imidazoline-phosphine ligand (aS,R,R)-L3 has been developed, affording the corresponding highly functionalized oxindole-fused spirotetrahydrofuran frameworks in good yields along with good diastereo- and high enantioselectivities under mild conditions.