Intramolecular 1,3-cycloadditions of aryl azides with alkynyl substituents: a kinetic investigation
Abstract
The formation of 4H-v-triazolo[5,1-c][1,4]benzoxazines (IIa–c) by thermal reaction of 2-(2-alkynyloxy)phenyl azides (Ia–c) has been studied kinetically in toluene and 3-methylbutan-1-ol at different temperatures. The solvent effect on the rate is small; activation enthalpies are of the order of 22–23 kcal mol–1; activation entropies range from –8 to –14 cal mol–1 K–1.