Rhodium-Catalyzed Desymmetric Arylation of γ,γ -Disubsituted Cyclohexadienones: Asymmetric Synthesis of Chiral All-Carbon Quaternary Centers.

The desymmetric arylation of prochiral cyclohexadienones with ArZnCl in the presence of an ( R )-segphos-rhodium catalyst gave high yields of the corresponding cyclohexenones, which contain a chiral arylated carbon center at the β -position and a chiral all-carbon quaternary center at the γ -position, with high diastereo- and enantioselectivities. This catalytic system was also applied to the arylation of spirocarbocyclic cyclohexadienones and afforded the corresponding cyclohexenones bearing a chiral spiro quaternary carbon with high dr and ee.