Michael Initiated Ring Closure Reactions in Aqueous Medium for the Synthesis of Spiro Cyclopropyl Oxindoles.

Oxindole ring is a privileged scaffold which is present in a number of natural products and molecules with a wide spectrum of pharmacological activities. Spiro oxindoles have attracted great interest as drug candidates and in recent years many synthetic methods for the construction of structurally and functionally diverse systems have appeared in the literature. In this field, we herein report a new general access to spiro cyclopropyl oxindoles with three-point of diversity: the substitution at the cyclopropane ring, at the aromatic ring and at the nitrogen atom. The synthetic method is based on a domino Michael Initiated Ring Closure strategy which employs variously substituted vinyl selenones and oxindoles as starting materials. In considerations of the growing interest in green and environmentally benign procedures, the use of water as alternative to standard organic solvents has been investigated.