Catalytic Asymmetric Synthesis of Cage-type Organic Compounds by New Stereo-controlled Approach

我报道了在手性锂试剂的作用下，非手性对环芳烃在ANSA链两端以氧原子为导向基团的对映选择性邻位锂化合反应。不可翻转的1，n-二氧杂[n]对环番(n？-11)与仲丁基锂和(-)-雀花碱反应，得到手性单硫化产物。在催化剂中加入仲丁基锂，生成C2对称的二锂化合物。这些锂盐被合适的亲电剂猝灭，得到了各种平面手性的芳环芳烃，它们的ee都很好。用上述方法合成的平面手性单膦和双膦配体被用作过渡金属催化反应的手性配体。

I reported an enantioselective ortho-lithiation of achiral paracyclophanes with oxygen atoms as directed moieties at both ends of ansa-chain using a chiral lithium reagent. The reaction of an unflippable 1,n-dioxa[n]paracyclophane (n?□11) with sec- utyllithium and (-)-sparteine gave the chiral mono-lithiated product. Additional amount of sec-butyllithium gave C_2-symmetric dilithiated product. The quenching of these lithium salts by appropriate electrophiles gave various planar-chiral aracyclophanes with excellent ee. The planar-chiral mono- and diphosphines, which were prepared by the above protocols, were used as chiral ligands in transition metal-catalyzed reactions.