Several thieno[2,3-h]-/[3,2-h]- and [2,3-f]quinolines have been synthesised from 2,3-dihalogenated pyridines or -quinolines by site-selective Pd catalysed cross-coupling reactions and Brønsted acid mediated cycloisomerisations as the final key step.

An effective and atom‐economic synthesis of quinolino[3′,4′:4,5]pyrrolo[1,2‐f]phenanthridines has been developed. The protocol involves a site‐selective Sonogashira reaction of 3,4‐dihaloquinoline, followed by a domino C–N coupling/hydroamination/C–H arylation reaction. Quinolino[3′,4′:4,5]pyrrolo[1,2‐f]phenanthridines represent a hitherto unknown class of heterocyclic compounds.

A concise and modular synthesis of pyrrolo[1,2-a][1,6]- and [1,8]naphthyridines by a one-pot two-step reaction consisting of electrophilic acylation followed by an alkyne-carbonyl-metathesis reaction as the final cyclization step is reported. This developed synthetic methodology allows the facile synthesis of these heterocyclic core structures in mainly high overall yields under metal-free conditions. Reaction conditions are carefully optimized and display a novel supplement to access these tricyclic heterocyclic compounds.