A divergent mechanistic course of Pd(0)-catalyzed aza-Claisen rearrangement and aza-Rautenstrauch-type cyclization of N-allyl ynamides.

A fascinating mechanistic study of ynamido-palladium-pi-allyl complexes is described that features isolation of a unique silyl ketenimine via aza-Claisen rearrangement, which can be accompanied by an unusual thermal N-to-C 1,3-Ts shift in the formation of tertiary nitriles and a novel cyclopentenimine formation via a palladium-catalyzed aza-Rautenstrauch-type cyclization pathway.