Synthesis of thieno[2,3-]-/[3,2-]quinolines and thieno[2,3-] quinolines by Brønsted acid mediated cycloisomerisation.

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. This newly developed synthetic strategy is used in a modular way to synthesize diverse regioisomeric derivatives, tolerates various functional groups, and proceeds with high selectivity, and the desired final products have been isolated in high overall yields.

Synthesis of furo[3,2-b:4,5-b']diindoles and their optical and electrochemical properties.

An efficient two-step palladium catalyzed synthesis of furo[3,2-b:4,5-b']diindoles, a hitherto unknown symmetrical heterocyclic core structure, was developed. The synthesis is based on a regioselective Suzuki-Miyaura cross coupling reaction of tetrabromofuran and subsequent double N-arylation. Selected compounds were studied with regard to their optical and electrochemical properties.

Synthesis of pyrrolo[1,2-a]naphthyridines by Lewis acid mediated cycloisomerization.

Pyrrolo[1,2-a]naphthyridines were synthesized from 3-alkynyl-2-([1H]-pyrrol-1-yl)pyridines and 3-alkynyl-4-([1H]-pyrrol-1-yl)pyridines by cycloisomerization. The reactions are performed by application of the Lewis acids PtCl or Bi(OTf) without the need of further additives. With the described methods a number of derivatives containing a variety of functional groups have been synthesized in up to 78% yield.