Metal-mediated entry to functionalized 3-substituted 3-hydroxyindolin-2-ones via regiocontrolled carbonylallylation, bromoallylation, 1,3-butadien-2-ylation, propargylation, or allenylation reactions of isatins in aqueous media

Abstract

Reactions of 2,3-indolinediones (isatins) with stabilized organometallic reagents were investigated in aqueous media. Isatins and a variety of stabilized organic halides undergo coupling under Barbier-type conditions in the presence of different metals (indium, tin, zinc) and additives (ammonium chloride, hydrobromic acid, bismuth(III) chloride, hafnium(IV) chloride). The regiochemistry of the processes (carbonylallylation, bromoallylation, 1,3-butadien-2-ylation, propargylation, or allenylation reactions) were generally excellent. On this basis, simple and fast protocols for the synthesis of the potentially bioactive 3-substituted 3-hydroxyoxindole moiety were developed.