Substrate-Controlled Three-Component Synthesis of Diverse Fused Heterocycles

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

Automated summary

A chemoselective strategy for the synthesis of various fused heterocycles was developed using a three-component condensation reaction of heterocyclic ketene aminals (HKAs) or corresponding thioaminals with aryl glyoxals and cyclic 1,3-dicarbonyl compounds. Depending on the combination of substrates, this strategy allows the straightforward access to imidazo[1,2-a]quinoline, pyrrolo[1,2-a]imidazole, and pyrrolo[2,1-b]thiazole frameworks.