Ynamides: A Modern Functional Group for the New Millennium

Diminishing the electron density by substituting the nitrogen atom and/or the alkyne with electronegative elements would appear to be a logical solution to improve the stability of ynamines and revitalize their synthetic utility. The synthetic eminence of ynamines is well merited because of the predictable regio-selectivity in their transformations, as shown by the generalization below, and, more importantly, because they are inherently highly reactive. However, this latter attribute is also the source of the limitation that has seriously hampered the development of ynamine chemistry, thereby shortening the period of its prominence in synthesis. The field of ynamide chemistry has experienced rapid expansion in the past decade, fueled by the development of efficient means of preparation. Beautiful work has been accomplished showcasing the unique reactivity of ynamides in a plethora of reactions that have delivered a diverse array of novel carbo- and heterocyclic structures.