Regioselective Synthesis of Enones via a Titanium-Promoted Coupling of Unsymmetrical Alkynes with Weinreb Amides

A modular titanium-promoted coupling of unsymmetrical internal alkynes with Weinreb amides is described. The coupling reaction takes place at room temperature and affords E-trisubstituted enones in moderate to good yields with high levels of regioselectivity. The system shows moderate chemoselectivity.