Trapping of N-Acyliminium Ions with Enamides: An Approach to Medium-Sized Diaza-Heterocycles.

Enamides equipped with N-acyliminium ion precursors were obtained through reduction of ynamides tethered to N-imides. Intramolecular TMSOTf-mediated trapping of N-acyliminium ions provided a variety of polyfunctionalized medium-sized diaza-heterocycles of putative pharmacological interest.