Indium/Fe(iii) – mediated regioselective β-cross-coupling aldol type addition reaction of activated alkenes with isatins/isatinimines in aqueous media

Abstract

A highly efficient and regioselective β-cross coupling aldol type addition reaction of activated alkenes with isatin/isatinimine derivatives in the presence of Indium/Fe(III) in THF/H₂O at room temperature is described. Our synthetic protocol explores a broad substrate scope and smoothly proceeds under base-free conditions. The resulting products are obtained in a short reaction time with moderate to high yields. This is the first example of Mannich-type coupling of isatinimines with activated alkenes to afford the alkyl 3-(2-oxo-3-(phenylamino)indolin-3-yl)propanoates and 3-(3-oxoalkyl)-3-(phenylamino)indolin-2-ones.