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A highly efficient direct asymmetric allylic substitution (AAS) reaction of 4-hydroxycoumarin derivatives with branched allylic alcohols was realized by combining a chiral iridium complex catalyst with a Lewis acid under mild reaction conditions, delivering various chiral allylation products in remarkably high yields and excellent enantioselectivities. The salient features of this transformation include mild reaction conditions, general substrate scope, good functional group tolerance, high yields, excellent selectivities and easy scale-up. Furthermore, the obtained products can be readily transformed into several kinds of bioactive compounds. [ABSTRACT FROM AUTHOR]

The combination of a transition-metal catalyst and organocatalyst was designed to achieve a highly enantioselective system for the allylic dearomatization reaction of naphthols with racemic secondary allylic alcohols. The desired β-naphthalenones, bearing an all-carbon quaternary center, were obtained in good yields with high chemo- and enantioselectivities. The cooperative catalytic system, involving a chiral iridium complex and phosphoric acid, provided measurable improvements in yields, and chemo- and enantioselectivities relative to single-catalyst systems. Control experiments indicated that the chiral iridium complex functions as a key species in the control of the absolute configuration, thus enabling the formation of both β-naphthalenone enantiomers by simply employing opposite enantiomeric ligands. [ABSTRACT FROM AUTHOR]