Li2[(1–4)3Ti]. The equilibrium is studied by 1H NMR. CD spectroscopy indicates that the configuration at the complex units of the enantiomerically pure dimeric α-chiral derivatives Li[Li3(1–3)6Ti2] is opposite to the configuration of the monomers Li2[(1–3)3Ti]. For the γ-chiral complex Li2[(4)3Ti] only a de of 25% is observed and in this case no interpretation of the mechanism of stereocontrol is possible
萜烯醇L(-)-
冰片醇,(1 S 2 S 3 S 5 R)-3-品醇,(-)薄荷醇和(-)-
美登醇是易于获得的手性醇,用于制备对映体纯的
儿茶酚酯1 –4 -H 2。这些
配体用于三
锂桥联双核
钛(IV)三
儿茶酚酯螺旋Li [Li 3(1-4)6 Ti 2 ]的分级组装。在溶液中,二聚体与单体Li 2 [(1-4)3处于溶剂依赖性平衡状态Ti]。通过1 H NMR研究平衡。CD光谱表明对映体纯的二聚α-手性衍
生物Li [Li 3(1-3)6 Ti 2 ]的复杂单元的构型与单体Li 2 [(1-3)3 Ti的构型相反]。对于γ-手性配合物Li 2 [(4)3 Ti],仅观察到de为25%,在这种情况下,无法解释立体控制机理。