Regiocontrolled cobalt-catalyzed Diels-Alder reactions of silicon-functionalized, terminal, and internal alkynes.

The efficient control of the regiochemistry of the Diels-Alder adducts which are formed in excellent yields from 1,3-dienes and alkynylsilanes can be realized utilizing cobalt complexes with a pyridine-imine ligand or a dppe ligand, respectively. The application of 2-trimethylsilyloxy-1,3-butadiene leads to a very interesting cyclohexenone derivative suitable for further transformations.