Intramolecular electrophilic hydroarylation via Claisen rearrangement: synthesis of chromenes, heterothiochromenes and heterodihydrothiochromenes

We have designed and synthesized several basic and novel fused ring heterocycles by intramolecular hydroarylation with an efficiency and scope to develop intermediates of potential value. This method demonstrated consistent performance with arene-ene and arene-yne substrates of diverse structural features, including propargyl ethers, allyl thioethers, and propargyl thioethers resulting in 6-endo products. (c) 2006 Elsevier Ltd.. All rights reserved.