Construction of dispirocyclopentanebisoxindoles via self-domino Michael-aldol reactions of 3-phenacylideneoxindoles.

A simple protocol for the construction of novel dispirocyclopentanebisoxindoles is accomplished by the base promoted domino reactions between two molecules of 3-phenacylideneoxindoles with the participation of solvents, alcohol, or other added nucleophiles such as amines or thiophenols. Significantly, this domino reaction results in the complex dispiro compounds with high yields and diastereoselectivity, which would allow construction of dispirocyclopentanebisoxindole with four and five diastereoisomeric centers using simple materials.