Substrate-Controlled Three-Component Synthesis of Diverse Fused Heterocycles.

A chemoselective strategy toward a variety of fused heterocyclic scaffolds relying on a three-component condensation of heterocyclic ketene aminals (HKAs) or corresponding thioaminals with aryl glyoxals and cyclic 1,3-dicarbonyl compounds has been developed and explored. Depending on the applied combination of substrates, the strategy can be tuned to provide straightforward access to imidazo[1,2-]quinoline, pyrrolo[1,2-]imidazole, and pyrrolo[2,1-]thiazole frameworks.