Assembly of 4H-chromenes, imidazobenzothiazines and quinazolines via copper-catalyzed domino reactions using 2-halobenzyl tosylates as substrates
- Publication Type
- Journal contribution (peer reviewed)
- Authors
- Omar, M. A.; Conrad, J.; Beifuss, U.
- Year of publication
- 2014
- Published in
- Tetrahedron
- Band/Volume
- 70/
- DOI
- 10.1016/j.tet.2014.06.071
- Page (from - to)
- 3061-3072
The use of 2-halobenzyl tosylates as substrates in copper-catalyzed domino intermolecular substitution/intramolecular arylation processes for the efficient and selective preparation of heterocycles is reported for the first time. Reaction of 2-halobenzyl tosylates with β-ketoesters delivers 4H-chromenes with yields ranging between 59 and 89%. Imidazobenzothiazines are formed with yields up to 82% upon reaction of 2-halobenzyl tosylates with 2-mercaptoimidazoles. When 2-halobenzyl tosylates are reacted with benzamidines the corresponding quinazolines are obtained.