Highly Chemo- and Regioselective Construction of Spirocarbocycles by a Pd(0)-Catalyzed Dearomatization of Phenol-Based Biaryls with 1,3-Dienes

A novel
Pd(0)-catalyzed intermolecular carbocyclization of phenol-derived
biaryls with 1,3-dienes has been implemented through a sequence of
oxidative addition to the C–I bond, regioselective olefin insertion,
and allylative dearomatization. This method provides a broad range
of attractive spirocyclic compounds bearing two contiguous tertiary/quaternary
carbon centers in good yields with excellent chemoselectivity and
regioselectivity. Moreover, preliminary results indicate that asymmetric
control of this process is feasible with chiral ligands.