Rémy Marine, Nierengarten Iwona, Park Boram, Holler Michel, Hahn Uwe, Nierengarten Jean-François
Laboratoire de Chimie des Matériaux Moléculaires, Université de Strasbourg et CNRS (UMR 7402 LIMA) Ecole Européenne de Chimie, Polymères et Matériaux, 25 rue Becquerel, 67087, Strasbourg Cedex 2, France.
Chemistry. 2021 Jun 10;27(33):8492-8499. doi: 10.1002/chem.202100943. Epub 2021 May 13.
Stable pillar[5]arene-containing [2]rotaxane building blocks with pentafluorophenyl ester stoppers have been efficiently prepared on a multi-gram scale. Reaction of these building blocks with various nucleophiles gave access to a wide range of [2]rotaxanes with amide, ester or thioester stoppers in good to excellent yields. The rotaxane structure is fully preserved during these chemical transformations. Actually, the addition-elimination mechanism at work during these transformations totally prevents the unthreading of the axle moiety of the mechanically interlocked system. The stopper exchange reactions were optimized both in solution and under mechanochemical solvent-free conditions. While amide formation is more efficient in solution, the solvent-free conditions are more powerful for the transesterification reactions. Starting from a fullerene-functionalized pillar[5]arene derivative, this new strategy gave easy access to a photoactive [2]rotaxane incorporating a C moiety and two Bodipy stoppers. Despite the absence of covalent connectivity between the Bodipy and the fullerene moieties in this photoactive molecular device, efficient through-space excited state interactions have been evidenced in this rotaxane.
已在多克规模上高效制备了带有五氟苯基酯封端基的含稳定柱[5]芳烃的[2]轮烷结构单元。这些结构单元与各种亲核试剂反应，能够以良好至优异的产率得到多种带有酰胺、酯或硫酯封端基的[2]轮烷。在这些化学转化过程中，轮烷结构得以完全保留。实际上，这些转化过程中起作用的加成-消除机制完全防止了机械互锁体系中轴部分的解扣。封端基交换反应在溶液中和机械化学无溶剂条件下均得到了优化。虽然酰胺形成在溶液中更高效，但无溶剂条件对酯交换反应更有利。从富勒烯功能化的柱[5]芳烃衍生物出发，这种新策略使得能够轻松得到一种包含一个C部分和两个Bodipy封端基的光活性[2]轮烷。尽管在这种光活性分子器件中Bodipy与富勒烯部分之间不存在共价连接，但在该轮烷中已证实存在有效的空间激发态相互作用。
