γ-CF₃-Allenamides versus 3-CF₃-Cyclopentenylamines: Substituent-Controlled Divergent Reaction of β-CF₃-1,3-Enynamides with β-Dicarbonyl Compounds

Abstract

A distinctive N-substituent-controlled regioselective 1,4-hydrocarbonation or 1,4-hydrocarbonation/5-endo-trig cyclization cascade reaction of β-CF 3 -1,3enynamides with β-dicarbonyl compounds in the presence of a simple base is reported. β-CF 3 -1,3-enynamides having a Ts group N-substituent produce γ-CF 3 -allenamides via a 1,4-hydrocarbonation process, whereas β-CF 3 -1,3-enynamides bearing a Ms group Nsubstituent lead to 3-CF 3 -cyclopentenylamines through a 1,4-hydrocarbonation/5-endotrig cyclization cascade process.