The Palladium-Catalyzed Intramolecular Alder-Ene Reactions of <i>O</i>- and <i>N</i>‑Linked 1,6-Enynes Incorporating Triethylsilyl Capping Groups

A series of <i>O</i>- and <i>N</i>-linked 1,6-enynes (e.g., <b>11</b>) have been prepared with each subjected to a palladium-catalyzed intramolecular Alder-ene (IMAE) reaction, thus producing the isomeric and cyclic 1,4-diene (e.g., <b>12</b>). These processes proceed most effectively when a triethylsilyl group is attached to the alkyne moiety and so generating alkenylsilanes that can be manipulated in various useful ways, including via iododesilylation (to give, for example, iodoalkene <b>62</b>).