Diels-Alder and Formal Diels-Alder Cycloaddition Reactions of Ynamines and Ynamides

Nitrogen-substituted alkynes such as ynamines and ynamides are competent partners in [4+2] cycloaddition reactions. This microreview aims to discuss in a historical context the main achievements in the work on this class of reactions that leads to valuable nitrogen-containing heterocycles in a single-step fashion. In the last section, our own work in the field of inverse-electron-demand Diels-Alder reactions between ynamides and pyrimidines is discussed.