Construction of fused, bridged, and spiro bicyclic skeletons via nickel-catalyzed intramolecular cyclization of cyclic 1,3-dienes and a tethered aldehyde

Nickel-catalyzed intramolecular cyclization of cyclohexa-1,3-dienes and an aldehyde in a chain produced fused, bridged or spiro bicyclic skeletons depending on the length of the tether. This chemistry can be extended to cyclohepta-1,3-dienes and cyclohepta-1,3,5-trienes having an aldehyde moiety on the side chain.