Synthesis of N -(acyloxy)- N -alkynylamides via generation of "C 2 " 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 ("C 2 ") 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 "C 2 ".