Synthesis of Quasi-Linear and Segmented Bis- to Penta-2,2‘-bipyridine Polytopic Ligands Built via a Convergent Approach
作者:Abderrahim Khatyr、Raymond Ziessel
DOI:10.1021/jo000836k
日期:2000.11.1
are presented. The first series of ligands bears a single alkyne function as a bridge and has been built by Pd(0)-catalyzed cross-coupling reactions between ethynylated and bromo-substituted derivatives of 2,2'-bipyridine (bipy). These new ligands provide access to numerous hexameric, octameric, and decameric pyridine-based materials. Optimum conditions were found with [Pd(PPh(3))(4)] (6 mol %) in benzene
提出了一种可靠而实用的方法,用于制备具有刚性和共轭间隔基的分段低聚2,2'-联吡啶基配体。第一组配体具有单个炔烃作为桥的作用,并且已通过Pd(0)催化的2,2'-联吡啶(联吡啶)的乙炔基和溴取代衍生物之间的交叉偶联反应构建。这些新的配体使人们可以使用多种基于六聚,八聚和十聚吡啶的材料。发现了最佳条件,条件是[Pd(PPh(3))(4)](6 mol%)在含苯的二异丙胺中,在80摄氏度下进行。第二系列可溶性配体是围绕1,4-二乙炔基-2,5合成的-二十二烷基氧基苯桥联单元。综合过程需要保护/脱保护方法,以及化学选择性钯催化的Sonogashira-Hagihara交叉偶联方案以获得目标多位配体。在该策略中,需要带有一个或两个联吡啶和苯基单元的关键性15b,17和19b中间体,并且此类实体已以极高的产率分离出来。该产品具有高度溶解性和光稳定性。在每种情况下,最后一步都涉及适当成分之间的双重交叉