Practical syntheses of a series of novel ynamides and allenamides are described here. While a base-induced isomerization protocol of propargyl amides leads to an array of chiral and achiral allenamides, ynamides are prepared from enamides via bromination followed by base-induced elimination of the Z-bromoenamides. These ynamides and allenamides possess improved thermal stability compared to ynamines and allenamines. They can be isolated, purified, and handled with ease, and thus, should be synthetically more useful than traditional ynamines and allenamines.
Bibliographical noteFunding Information:
R. P. H. thanks the American Cancer Society for an institutional grant [IRG-58-001-40-IRG-26]. R. P. H. also thanks R. W. Johnson Pharmaceutical Institute for a generous grant from the Focused Giving Program. C. J. D. thanks Pharmacia-Upjohn and UMN Department of Chemistry Lando/NSF Program for Summer Research Fellowships.