Cu(I)-Catalyzed Oxidative Cyclization of Enynamides: Regioselective Access to Cyclopentadiene Frameworks and 2-Aminofurans.

An efficient Cu(I)-catalyzed oxidative cyclization of alkynyl-tethered enynamides for the construction of fused bicyclic cyclopentadiene derivatives is disclosed. The cascade proceeds through alkyne oxidation, carbene/alkyne metathesis, and formal (3 + 2) cycloaddition. Employing aryl-tethered enynamides as starting materials, substituted 2-aminofurans can be exclusively formed.