Abstract:

The pyrrol and indol ring structures are quite common in natural compounds and unnatural derivatives with relevant biological activities. The synthesis of such structural scaffold combined in the same compound is a theme of ongoing interest. Bergman and coworkers reported the two component synthesis of 2-pyrrolo-3’-yloxindoles reacting 3-acetonylindenoxindole and enaminone in toluene under reflux for several hours. More recently, Powell and coworkers described the synthesis of one 2-pyrrolo-3’-yloxindole nucleus via tri-component reaction of 3-acetonylindenoxindole, ethyl acetoacetate and NH4OAc under catalysis of ionic liquids in excellent yield. Multicomponent reaction (MCRs) are excellent strategies due its efficiency "one-pot", atom economy, reduced numbers of steps, with the use of simple molecules in order to obtain compounds with high degrees of complexity. Herein, we describe a tri-component reaction mediated by microwave radiation and without catalysis, which allowed the synthesis of densely substituted 2-pyrrolo-3’-yloxindoles.