Copper(II)-catalyzed oxidation of 4-carboxythiazolines and 4-carboxyoxazolines to 4-carboxythiazoles and 4-carboxyoxazoles
摘要:
A mild copper(II)-catalyzed oxidation of 4-carboxythiazolines and 4-carboxyoxazolines to 4-carboxythiazoles and 4-carboxyoxazoles has been developed. Various substrates with alkyl or aryl substitutions at 2-position on azoline ring could be smoothly oxidized to the desired products in good to excellent yields. Moreover, the hydrolysis of the ester group could be avoided under this method. (C) 2011 Elsevier Ltd. All rights reserved.