Aqueous Morita–Baylis–Hillman Reaction of Unprotected Isatins with Cyclic Enones

Abstract

The readily available bicyclic imidazolyl alcohol <b>1</b> is a unique catalyst for the aqueous Morita–Baylis–Hillman (MBH) reaction between unprotected isatins and cyclic enones that gives access to a variety of potentially very useful 3-substituted 3-hydroxy-2-oxindoles in an operationally simple, efficient, and environmentally friendly way. The hydroxyl group of the catalyst is believed to stabilize the betaine intermediate formed in the first step of the MBH reaction