N-Functionalized 1-Alkynylamides: New Building Blocks for Transition Metal Mediated Inter- and Intramolecular [2+2+1] Cycloadditions

A conceptually new, stereoselective approach to compounds such as 1 and 2 is expected from the so far unknown class of N-functionalized 1-alkynylamides. Building blocks of the type I and II can be applied to inter- and intramolecular, regio- and stereoselective Co₂(CO)₈]-mediated 2+2+1] cycloadditions.