Selective Synthesis of ( Z )- and ( E )-β-Fluoro-α,β-Unsaturated Amides Using Palladium-Catalyzed Aminocarbonylation.

The selective synthesis of ( Z )- and ( E )-β-fluoro-α,β-unsaturated amides via the palladium-catalyzed aminocarbonylation of 1-fluoro-2,2-diiodovinylarenes is described in the present study. Using {Pd(allyl)Cl} 2 as a catalyst and DBU as a base in DMF, the primary product is ( Z )-isomers. Conversely, the use of a Xantphos ligand along with {Pd(allyl)Cl} 2 and Et 3 N as the bases in 1,4-dioxane leads to the selective formation of ( E )-isomers. Notably, 1-fluoro-2,2-diiodovinylarenes with various substituents on the phenyl ring react with various secondary amines, producing the corresponding ( Z )-isomeric amides with a high yield and selectivity. In contrast, ( E )-isomeric amides exhibit lower yields and restricted applicability.