Combinatorial synthesis of spiro[indoline-3,2′-pyrrole] derivatives via a three-component reaction under catalyst-free conditions

Abstract

Reported here is a convenient catalyst-free method for preparing a series of spiro[indoline-3,2′-pyrroles] from a three-component reaction of isatins, α-amino acid and phenylpropiolic acid esters in refluxing isopropanol with high regioselectivity and yields. A plausible mechanism for this process was proposed. In addition, this protocol permitted the facile construction of spiro[indoline-3,2′-pyrroles] through an expanded scope of substrates.