A phosphine-catalyzed γ/γ-addition of oxindoles with allenoates has been developed that enables the efficientsynthesis of highly functionalized symmetrical 3,3-disubstituted oxindoles. This protocol features mild reaction conditions and wide functional group tolerance and affording corresponding addition products in good to excellent yields. Besides, we have also investigated the biological utility
[3 + 2] annulations of spirocyclopropyl oxindoles with ynamides to offer biologically important spirocyclopenteneoxindoles in high yields with good diastereoselectivities were developed.