Palladium-catalyzed enantiospecific reaction of propargylic carbonates with phenols: Cascade chirality transfer

[GRAPHICS] A cascade chirality transfer process has been achieved by the palladium-catalyzed reaction of substituted propargylic carbonates with phenols. The reaction proceeds in a highly enantiospecific manner to produce chiral cyclic carbonates, which supports the existence of the pi-propargylpalladium intermediate in the reaction mechanism. The (E)- and (Z)-selectivity of the products can be controlled by choice of the phosphine ligand.