Ruthenium‐Catalyzed Cycloaddition of Nitrile Oxides and Alkynes: Practical Synthesis of Isoxazoles

3,4-Disubstituted and 3,4,5-trisubstituted isoxazoles have been formed from alkynes and nitrile oxides in a ruthenium(II)-catalyzed process (see scheme; cod=cycloocta-l,5-diene, Cp*=C5Me5). These reactions are experimentally simple, proceed at room temperature, and produce isoxazoles with excellent regioselectivity in high yield. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z801920_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.