Multi-Component Reaction of Amines, Alkyl Propiolates, and Ninhydrin: An Efficient Protocol for the Synthesis of Tetrahydro-dihydroxy-oxoindeno[1,2-b]pyrrole Derivatives

A new protocol for the synthesis of a series of tetrahydro-dihydroxy-oxoindeno[1,2-b]pyrrole from simple primary amines, alkyl propiolates, and ninhydrin was developed. The key step in the synthesis is an efficient three-component reaction of an amine with an alkyl propiolate to give a 3-amino acrylate derivative, which then reacts with ninhydrin.