A palladium-catalyzed, syn-selective aminoalkynylation of mono-, di- and trisubstituted olefins to afford pyrrolidines is developed. The combination of iodoalkynes and a picolinamide as nucleophile is shown to be essential for the observed reactivity. Furthermore, the picolinamide enables the rapid synthesis of cyclization substrates through a C−H activation approach.
Palladium-catalyzed aminoalkynylation of electronically unbiased olefins with iodoalkynes is reported. The picolinamide auxiliary enables for the first time the syn-selective aminoalkynylation of mono-, di- and trisubstituted alkenes to afford the corresponding pyrrolidines in up to 97 % yield and as single diastereomers. Furthermore, through a C−H activation approach, the picolinamide allows the rapid synthesis of functionalized olefins, which are suitable cyclization precursors. Facile and orthogonal deprotection of the amides and Si
Pr3-acetylenes in the products, and a subsequent Pictet–Spengler reaction is demonstrated.Zum Volltext