A General Protocol for the Aqueous Morita‐Baylis‐Hillman Reaction between Cyclic Enones and 1,2‐Dicarbonyl Compounds

In this report, we present an extensive methodological study of the aqueous Morita–Baylis–Hillman (MBH) reaction of a range of cycloenones with di‐ and tricarbonyl compounds, such as glyoxal derivatives, aliphatic and aromatic α‐keto esters, 1,2‐diketones, diethyl ketomalonate, ninhydrin, acenaphthenequinone, and phenanthrene‐9,10‐dione, through mediation of a bicyclic imidazolyl alcohol (BIA) as catalyst in aqueous medium. The desired MBH adducts were obtained in up to 98 % yield. The synthetic applicability of the MBH adducts was demonstrated by the preparation of an acenaphtho[1,2‐b]indole derivative. A general methodology for the Morita‐Baylis‐Hillman reaction of cycloenones and a variety of di‐ and tricarbonyl compounds. The methodology involves the use of a bifunctional Lewis base as catalyst in aqueous medium at room temperature. The synthetic applicability of the polyfunctionalized MBH adducts is demonstrated by the preparation of an acenaphtho[1,2‐b]indole derivative.