(A) catalytic route to cyclic amidines with aminoalkyne and electron deficient azide

Abstract

A Catalytic Route to Cyclic Amidines with Aminoalkyne and Electron Deficient Azide The synthesis of cyclic amidines turned out to have different mechanism with the synthesis of amidines by Cu-catalyzed three-component coupling of sulfonyl azide, alkyne and amine. It is also the type of multicomponent reaction. However, instead of three components it has two components in one molecule as aminoalkyne and the other component as electron deficient azide. It proceeds via sequential pathway which is hydroamination, addition of azide and rearrangement with three components in two molecules. The reactions of intramolecular hydroamination of aminoalkyne usually need high temperature. In contrast to it, the synthesis of cyclic amidine, the later reaction accelerates the former reaction, hydroamination. Therefore, the condition of reaction is much milder than that of normal hydroamination. We proposed the plausible mechanism from various experiments and we have demonstrated that the reaction has broad azide scope which makes cyclic amidine moiety more useful.