Synthesis of N-(acyloxy)-N-alkynylamides via generation of "C2" from hypervalent alkynyliodane and a weak base.

The first synthesis of N-(acyloxy)ynamides was realized through the coupling of N-(acyloxy)amides and hypervalent alkynyliodane under mild conditions. This reaction probably involves biradical species ("C2") generation and radical processes. Furthermore, we also demonstrated that N-(acyloxy)ynamide could be transformed into a N-sulfonylimidate derivative by a copper catalyst. This study provides new building blocks for synthetic organic chemistry reactions and improves understanding of the chemical reactivity of "C2".