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 2007(8): 0800-0800
DOI: 10.1055/s-2007-968788
DOI: 10.1055/s-2007-968788
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York
Cu-Mediated Synthesis of Pyrazoles via 1,3-Dipolar Cycloaddition
X. Qi, J. M. Ready*
University of Texas Southwestern Medical Center at Dallas, USA
Weitere Informationen
Publikationsverlauf
Publikationsdatum:
24. Juli 2007 (online)
Significance
Reported is a one-pot Cu(I)-mediated synthesis of pyrazoles via a 1,3-dipolar cycloaddition reaction of lithium acetylides and α-diazocarbonyl compounds. As expected, the cycloaddition is regioselective, which is consistent with theoretical predictions for cycloadditions involving HOMO-LUMO interactions (e.g., J. Bastide, N. El Ghandour, O. Henri-Rousseau Tetrahedron Lett. 1972, 13, 4225; K. N. Houk Acc. Chem. Res. 1975, 8, 361). Electron-rich and electron-poor acetylenes performed well and the process tolerated many functional groups, for example halides, esters, and nitriles.