Lewis acid-catalyzed [3 + 2] annulations of oxindole based spirocyclic donor–acceptor cyclopropanes with ynamides

Abstract

[3 + 2] annulations of oxindole based spirocyclic donor–acceptor cyclopropanes and ynamides catalyzed by copper triflate have been developed for the synthesis of biologically important spirocyclopenteneoxindoles. These reactions tolerated a wide scope of substrates and provided the desired products in good to high yields (up to 90%) with up to >40 : 1 diastereoselectivities under mild conditions.