Palladium-mediated Formation of N-Acyl-2-hydroxyindolines: A New Entry into N-Acylindoles

Abstract

N-Acyl-2-iodoanilines were reacted with vinylene carbonate in the presence of palladium(l1) acetate to give N-acyl-2-hydroxyindolines, in good yields, which on acid treatment afforded the corresponding Nacylindoles.Recently, Torii and co-workers' have reported an efficient palladium-mediated tandem three-component coupling process to construct the prostaglandin analogues (Scheme 1).Thus, the reaction allowed the coupling of norhomene with a halo olefin and cyanide to give stereoselectively a 2.3-substitutednorbomane in a satisfactory yield.Since we were interested in using an aromatic halide carrying a nucleophilic center in the same molecule in this reaction, we examined the reaction between vinylene carbonate (1) and an o-iodoaniline derivative (2) under the same palladium-mediated conditions.We expected that the iodoaniline (2) would behave as the two components in the Toni's precedents1 to add to 043 + Pd(OAc), (cat.)