Copper-catalyzed aerobic oxidative C–O bond formation for the synthesis of 3,5-disubstituted isoxazoles from enone oximes

Abstract

A direct access to 3,5-disubstituted isoxazoles has been accomplished through an intramolecular oxidative coupling reaction of enone oximes using a catalytic quantity of Cu(OAc)₂. This method features an inexpensive metal catalyst, molecular oxygen as a green oxidant, good functional group tolerance and readily available starting materials. This attractive method for the synthesis of isoxazole derivatives is of great significance due to the product's versatile reactivity for further transformations.