Diastereodivergent synthesis of bispirooxindoles via asymmetric Friedel-Crafts/aldol cascade reaction: co-catalyst effects on diastereoselective outcomes.

A combination of metal- and organo-catalysts sequentially catalyzing the Friedel-Crafts/aldol tandem reaction between 3-pyrrolyl-oxindoles and isatin-derived ß,γ-unsaturated α-ketoesters has been reported, which leads to two types of diastereomeric enantio-enriched bispirooxindoles with three quaternary stereocentres and synthetically valuable functional groups in high yields with excellent enantioselectivity and diastereoselectivity.