Concise and Stereoselective Synthesis of Enamides and Dienamides by a Titanium-Mediated Coupling Method

Ynamide−titanium alkoxide complexes underwent hydrolysis or addition to aldehydes and ketones to give single, stereodefined di- or trisubstituted enamides in good yields. Alternatively, coupling of a variety of alkyne−titanium alkoxide complexes with terminal ynamides generated amino-substituted titanacyclopentadienes, hydrolysis or aldehyde addition of which afforded stereodefined dienamides.