An Expedient Lewis‐Acid‐Catalyzed Microwave‐Assisted Domino Approach to Coumarin‐Fused Pyrroles and Related Heterocycles under Neat Conditions

A superior Lewis acid‐catalyzed and microwave‐assisted, facile, solvent‐free, one‐pot quick access to a novel class of a set of diversely substituted coumarin, dimedone and naphthoquinone‐fused pyrroles via an annulation reaction between different kinds of carbo‐and heterocyclic enaminones and a group of α‐aroyl/heteroaryl/acetylidene malonates, 3‐aroylidene‐2‐oxindoles is reported. This LUMO‐lowering technique involving a powerful Lewis acid relies on the installation of pyrrole rings good to high chemical yields with a wide scope of diversely substituted substances. Furthermore, a direct C(sp 3 )‐H hydroxylation of 3‐pyrrolocoumarinyl‐2‐oxindoles to therapeutically exciting 3‐hydroxy‐3‐pyrrolocoumarinyl‐2‐oxindoles bearing a tetra‐substituted chiral carbon center in high yields was achieved under metal‐free conditions.