Macrocyclization on the fullerene core: Direct regio- and diastereoselective multi-functionalization of [60]fullerene, and synthesis of fullerene-dendrimer derivatives
作者:Jean-François Nierengarten、Tilo Habicher、Roland Kessinger、Francesca Cardullo、François Diederich、Volker Gramlich、Jean-Paul Gisselbrecht、Corinne Boudon、Maurice Gross
DOI:10.1002/hlca.19970800721
日期:1997.11.3
induce dramatic changes in the chiroptical properties of the tether chromophore such as strong enhancement and reversal of sign of the Cotton effects in the circular dichroism (CD) spectra (Figs. 4 and 5). By the same method, the functionafized bis-adducts 50 and 51 (Schemes 10 and 11) were prepared as initiator cores for the synthesis of the fullerene dendrimers 62, 63, and 66 (Schemes 12 and 13) by
双重Bingel反应中的buckminsterfullerene,C 60和双丙二酸酯衍生物之间的大环化为制备具有高区域选择性和非对映选择性的C 60的共价双加合物提供了一种通用而简单的方法。光谱分析,立体化学因素和X射线晶体学的结合(图2)表明,在可能的进,出和出立体异构体中,双丙二酸酯的反应由o-联结,间-或对-亚二甲苯基系链仅提供外链式(方案1)。相反,使用衍生自1,10-菲咯啉的较大束缚物也提供了进出产品的第一个示例(±)-19(方案2)。从光学纯的双丙二酸酯衍生物开始,新的双官能化方法允许光学活性的富勒烯衍生物的非对映选择性制备(方案4和5),并最终实现了光学活性的顺式对映体的对映选择性制备(对映体过量ee> 97%)。3个双加合物,它们的手性完全由加成模式引起(图6)。具有光学活性的9,9'-spirobi [9 H]的双丙二酸酯的大环固定-芴]衍生的系绳至C 60下产生的24和耳鼻喉科-