Enantioselective Michael Spirocyclization of Palladium Enolates

We report an enantioselective and diastereoselective
Michael spirocyclization
reaction of tetrasubstituted palladium enolates. This allows for the
formation of adjacent all-carbon quaternary and tertiary stereocenters
in good yield, dr, and ee. Various subsequent cyclization reactions
enable access to a diverse range of tricyclic scaffolds. The mechanism
of this transformation and the origins of stereoselectivity are investigated
via quantum mechanics calculations.