Water, an Essential Element for a Zn -Catalyzed Asymmetric Quinone Diels-Alder Reaction: Multi-Selective Construction of Highly Functionalized cis-Decalins.

A Zn complex of a C -chiral bisamidine-type sp N bidentate ligand (L ) possessing two dioxolane rings at both ends catalyzes a highly efficient quinone asymmetric Diels-Alder reaction (qADA) between o-alkoxy-p-benzoquinones and 1-alkoxy-1,3-butadienes to construct highly functionalized chiral cis-decalins, proceeding in up to a >99:1 enantiomer ratio with a high generality in the presence of H O (H O:Zn =4-6:1). In the absence of water, little reaction occurs. The loading amount of the chiral ligand can be minimized to 0.