Chiral tetrafluorobenzobarrelenes as highly efficient ligands for the rhodium-catalyzed asymmetric 1,4-addition of arylboronic acids

New C-2-symmetric chiral diene ligands hearing a tetrafluorobenzobarrelene framework and (-)-menthyl groups as chiral auxiliaries were prepared through 14 + 21 cycloaddition of 1,4-bis((-)-menthoxymethyl)benzene with tetrafluorobenzyne. The diene ligands realized the rhodium-catalyzed asymmetric addition of arylboronic acids to alpha,beta-unsaturated carbonyl compounds giving beta-arylcarbonyl compounds in high yields with high enantioselectivity.