Bridging homogeneous and heterogeneous catalysis with CAN·SiO2 as a solid catalyst for four-component reactions for the synthesis of tetrasubstituted pyrroles†
Abstract
An efficient and expeditious method has been developed for the synthesis of tetrasubstituted pyrroles via a four component, one-pot cyclocondensation reaction of amines, aldehydes, dialkyl acetylenedicarboxylates and nitroalkanes using silica supported ceric ammonium nitrate as a heterogeneous catalyst for the first time. Reusable silica supported ceric ammonium nitrate was found to be a highly efficient and renewable heterogeneous catalyst for the rapid and convenient synthesis of tetrasubstituted pyrrole derivatives. The advantageous features of this novel methodology are high atom-economy, operational simplicity, shorter reaction times, convergence, and facile automation.