Palladium-catalyzed asymmetric [3+2] cycloaddition to construct 1,3-indandione and oxindole-fused spiropyrazolidine scaffolds†
Abstract
Palladium-catalyzed asymmetric [3+2] cycloaddition of 3-diazooxindoles with 2-vinylspiro[cyclopropane-1,2′-indene]-1′,3′-dione proceeded smoothly in the presence of chiral imidazoline–phosphine ligands to give the corresponding highly functionalized spiropyrazolidine derivatives in good to excellent yields (52–99%) along with good enantioselectivities (48–82% ee) under mild conditions.