Metal-free halonium mediated acetate shifts of ynamides to access a-halo acrylamides/acrylimides
Abstract
A metal-free acetate shift of 3-acetoxy ynamides to access a-iodo, bromo, and chloro acrylamides/acrylimides under very mild conditions is demonstrated. The inherent alkyne activation of ynamides is sufficient to ensure the a-halo acrylamides/acrylimides in high yields without the addition of a catalyst. In all cases high Z-stereoselectivity is observed. © 2011 American Chemical Society.