RSS-Feed abonnieren
Bitte kopieren Sie die angezeigte URL und fügen sie dann in Ihren RSS-Reader ein.
https://www.thieme-connect.de/rss/thieme/de/10.1055-s-00000131.xml
Synfacts 2010(7): 0759-0759
DOI: 10.1055/s-0029-1220132
DOI: 10.1055/s-0029-1220132
Synthesis of Heterocycles
© Georg Thieme Verlag
Stuttgart ˙ New York
Copper(I)-Catalyzed Synthesis of Benzoxazoles and Benzimidazoles
G. Shen*, W. Bao*
Zhejiang University, Hangzhou, P. R. of China
Weitere Informationen
Publikationsverlauf
Publikationsdatum:
22. Juni 2010 (online)
Significance
Reported is a synthesis of benzoxazoles and benzimidazoles by a ligand-free copper-catalyzed C-N coupling-cyclization reaction of ortho-halophenols with ortho-haloanilines. Among the copper sources, CuI showed the highest catalytic activity. Polar solvents, for example MeCN, were shown to give higher yields of products than unpolar solvent, for example toluene. The N,N-dimethylglycine ligand was shown to afford a slightly higher yield under the same reaction conditions. A mechanism of sequential phenol and aniline addition to carbodiimide followed by intramolecular C-N coupling was proposed without verification.