Development of the Catalytic Asymmetric Tandem Reactions

我们发现了镍催化的烯酮、炔烃、二甲基锌和氯三甲基硅烷的不对称多组分偶联反应。有趣的是，含有简单的单齿手性恶唑类化合物的催化体系在得到光学活性偶联产物方面非常有效，这些化合物以前一直被用作有价值的手性助剂。相反，在不对称催化中被广泛用作过渡金属配体的一些具有光学活性的有机磷配体和双齿恶唑啉却没有给出对映体选择性。此外，我们还发现在镍和铝的催化体系中，烯酮和炔烃发生了不对称的环三聚反应。手性单恶唑啉配体在反应中也是有效的。

We have found a nickel-catalyzed asymmetric multiple-component coupling of enones, alkynes, dimethylzinc, and chlorotrimethylsilane. Interestingly, catalytic systems involving simple monodentate chiral oxazolines, which have been previously used as valuable chiral auxiliaries, were very effective in giving optically active coupling products. In contrast some optically active organophosphorus ligands and bidentate oxazolines, which have been extensively used as ligands for transition metals in asymmetric catalysis, did not give enantioselection. Moreover, we have found an asymmetric cyclotrimerization of enones and alkynes in the presence of a catalytic system of nickel and aluminum. The chiral monooxazoline ligands were also effective in the reaction.