Recent progress in metal catalysis has arisen from dramatic improvements in catalytic performance using multinuclear complexes. There has been great interest in controlling the synergistic and cooperative effects between the metal centers in such complexes; however, the complicated nature and restriction of the ligand framework make it difficult to design tri-, tetra-, and multinuclear complexes.[1] For example, there are excellent reports concerning rhodium-or rutheniumlinked oligomeric complexes for heterogeneous asymmetric hydrogenation; the improvement of catalytic activity and stereoselectivity remains untouched.[2] Therefore, the design of ligand architectures and the demonstration of excellent catalytic activity using multinuclear complexes, including oligomeric complexes, are the next challenge in organic chemistry. We describe herein the dramatic effect of a multinuclear complex, having both copper and zinc centers, upon catalytic performance. The catalytic performance achieved was much higher than that of previous systems in the copper-catalyzed asymmetric conjugate addition of organozinc reagents to acyclic enones. Our working hypothesis is shown in Scheme 1. The deprotonation reaction of the phosphorus ligand 1, which bears a hydroxy moiety, by an organometallic reagent generates metal-linked ligand 2, the phosphorus moieties of which coordinate to transition-metal centers to form the tetranuclear complex 3. Such a pliable ligand scaffold as 1 makes it possible to tune the structural and electronic features.The metal-linked scaffold prompted us to examine the copper-catalyzed asymmetric conjugate addition of organozinc reagents to enones using (R)-3,3'-bis(diphenylphosphino)-[1,1'-binaphthalene]-2,2'-diol (L1).[3] To identify the optimal ligand structure, binol derivatives L1-L3 were examined ( Table 1). The reaction of Et 2 Zn and (E)-chalcone (4 a) was conducted in the presence of CuCl 2 ·2H 2 O and the ligand in THF at either 0 8C or À20 8C. [4,5] The reaction using simple (R)-binol (binol = 1,1'-binaphthol) at 0 8C was examined but it did not proceed at all (Table 1, entry 1). In contrast, the reaction using Et 2 Zn (1.5 equiv) in the presence of L1 was complete in 1 hour at 0 8C to give the product 5 a in 67 % yield with 92 % ee (Table 1, entry 2). The mixture of CuCl 2 ·2 H 2 O and L1 in THF gave a white suspension, and when this was treated with Et 2 Zn a homogeneous solution resulted. How- [b] ee [%] [c]

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Multinuclear Cu/Zn complex-catalyzed efficient asymmetric conjugate addition of organozinc reagents to acyclic and cyclic enones has been developed in the presence of a wide variety of regioisomeric chiral diols bearing phosphorus moieties as ligands. The regioisomeric SPINOL-PHOS ligands based on a SPINOL architecture showed an unexpected inversion of stereoselectivity.