Direct Multicomponent Synthesis of C3-Arylated Pyrroles under Catalyst-Free Conditions

Abstract

An operationally simple catalyst-free protocol for the direct regiospecific synthesis of C3-arylated/alkenylated pyrrole has been developed. The enamine-intermediate, in situ generated from succinaldehyde and a primary amine, was trapped with activated carbonyls before the Paal-Knorr reaction in a direct multicomponent “just-mix” protocol to furnish pyrroles in good yields. Several C3-substituted N-alkyl pyrroles have been produced under open-flask conditions, avoiding protection-deprotection chemistry.