Ruthenium-catalyzed cycloaddition of nitrile oxides and alkynes: Practical synthesis of isoxazoles
(Chemical Equation Presented) 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 reaction