Vinylazaarenes as dienophiles in Lewis acid-promoted Diels-Alder reactions.

Described are the first examples of Lewis acid-promoted Diels-Alder reactions of vinylpyridines and other vinylazaarenes with unactivated dienes. Cyclohexyl-appended azaarenes constitute a class of substructures of rising prominence in drug discovery. Despite this, thermal variants of the vinylazaarene Diels-Alder reaction are rare and have not been adopted for synthesis, and Lewis acid-promoted variants are virtually unexplored.