Synthesis of Bicyclo[2.2.2]octenols via Ni(0)-Catalyzed Alkylative Cyclization of Multi-functional Aldehydes

Nickel-catalyzed three-component coupling reactions of α,β,γ,δ-unsaturated dienals, alkynes, and alkynyltin reagents to produce more functionalized aldehydes have been achieved. The aldehydes produced were subjected to a Ni(0)-catalyzed alkylative cyclization reaction to provide direct access to highly functionalized bicyclo[2.2.2]octenols. In addition to their existence as substructures of complex natural molecules, these compounds possess interesting stereochemical properties, and can be interesting three-dimensional scaffolds for library design.