Palladium-Catalyzed Silylcyanation of Ynamides: Regio- and Stereoselective Access to Tetrasubstituted 3-Silyl-2-Aminoacrylonitriles

The palladium-catalyzed silylcyanation of ynamides is described. This reaction is fully regioselective, delivering tetrasubstituted 2-aminoacrylonitriles derivatives exclusively. Unexpectedly, the nature (aryl or alkyl) of the substituent located at the beta-position of the ynamide directly controls the stereoselectivity. The reaction tolerates a number of functional groups and can be considered as the first general access to fully substituted 2-aminoacrylonitriles. Given the singular reactivity observed, a computational study was performed to shed light on the mechanism of this intriguing transformation. Relying on the specific reactivity of the newly installed vinylsilane functionality, the scope of 2-aminoacrylonitriles has been enlarged by postfunctionalization.

Automated summary

The palladium-catalyzed silylcyanation of ynamides is highly selective, producing exclusively tetrasubstituted 2-aminoacrylonitriles derivatives. The stereoselectivity is directly controlled by the nature of the substituent at the beta-position of the ynamide. The reaction is tolerant of various functional groups and provides a general method to access fully substituted 2-aminoacrylonitriles. The mechanism of this intriguing transformation is elucidated by computational study, and the range of 2-aminoacrylonitriles is expanded through postfunctionalization using the newly installed vinylsilane functionality.