Ti Catalyzed Hydroamination: A Direct Functionalization of Cu Acetylide

In the presence of a bis-amidate-bis-amido Ti pre-catalyst, an NHC supported Cu acetylide was reacted with p-toluidine to generate a new Cu containing species almost quantitatively. The product was analyzed by NMR spectroscopy and X-ray single crystal diffraction to be a Cu enamide. Preliminary mechanistic studies suggest the reaction follows well accepted [2+2] cycloaddition mechanism for early transition metal catalyzed hydroamination. Furthermore, the reaction is likely to be a direct functionalization of the alkyne moiety of the Cu acetylide.