The Virtue of Palladium-Catalyzed Domino Reactions − Diverse Oligocyclizations of Acyclic 2-Bromoenynes and 2-Bromoenediynes

The domino-type combination of consecutive palladium-catalyzed cross-coupling reactions with subsequent pericyclic transformations offers a very fast access to various oligocyclic skeletons. This Account highlights all-intramolecular, intra-intermolecular, and all-intermolecular organopalladation cascades leading to 1,3,5-hexatrienes, which undergo consecutive 6π-electrocyclizations with closure of three, two, or just one ring, respectively. Sequences of cross-coupling reactions and Diels−Alder additions are also discussed, as well as tricyclizations of 2-bromoenediynes giving rise to bisannelated benzene and fulvene derivatives.