Ultrafast and Diastereoselective Synthesis of 3-Spirocyclopropyl-2-oxindoles Bearing Three Continuous All-Carbon Quaternary Centers

Synthesis of 3-spirocyclopropyl-2-oxindoles bearing three continuous all-carbon quaternary centers by the domino Michael-alkylation reaction between 3-chlorooxindole and isatylidenemalononitrile is described. Remarkably, the reaction proceeded in exceptionally high efficiency (up to 99% yield within 2 min) and excellent diastereoselectivity (>25:1 dr for all the examples).