Improvement of the reactivity of the acyl azides to synthesize the cyclic acyl amidines

초록

Our previous work has been focused on the development of strategies for the synthesis of cyclic amidines present in a variety of natural and pharmacological molecules. We have reported the synthesis of 6-membered cyclic amidine by utilizing the [3+2] cycloaddition of sulfonyl azide to an enamine intermediate from borane-catalyzed dearomatization of N-heteroarene.In our previous investigations, it was reported that the reaction between the enamine intermediate and the acyl azide did not proceed because acyl azide was less reactive than sulfonyl azide. Although the benzoyl azide and enamine intermediates have shown low reactivity, it was possible to improve the reactivity by attaching functional groups to the benzoyl azide. Herein, we report synthesis of various cyclic acyl amidines from electron withdrawing acyl azides.