Boronated enynes as versatile sources of stereodefined and skeletally diverse molecules.

[reaction: see text] The application of a one-pot palladium-catalyzed cycloisomerization of enynes 1/Diels-Alder cycloaddition/allylboration sequence efficiently generates tricyclic structures with complete control of the four stereogenic centers. Ruthenium and platinum catalysts perform distinct transformations providing other isomeric boron-substituted cyclic compounds.