Natural reaction cascades control the movement of biomolecules between cellular compartments. Inspired by these systems, we report a synthetic reaction cascade employing post-assembly modification reactions to direct the partitioning of supramolecular complexes between phases. The system is composed of a self-assembled tetrazine-edged Fe^II₈L₁₂ cube and a maleimide-functionalized Fe^II₄L₆ tetrahedron. Norbornadiene (NBD) functions as the stimulus that triggers the cascade, beginning with the inverse-electron-demand Diels–Alder reaction of NBD with the tetrazine moieties of the cube. This reaction generates cyclopentadiene as a transient by-product, acting as a relay signal that subsequently undergoes a Diels–Alder reaction with the maleimide-functionalized tetrahedron. Cyclooctyne can selectively inhibit the cascade by outcompeting NBD as the initial trigger. Initiating the cascade with 2-octadecyl NBD leads to selective alkylation of the tetrahedron upon cascade completion. The increased lipophilicity of the C₁₈-tagged tetrahedron drives this complex into a non-polar phase, allowing its isolation from the initially inseparable mixture of complexes.

中文翻译：

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共价后组装修饰级联中的信号转导

自然反应级联控制生物分子在细胞区室之间的运动。受这些系统的启发，我们报告了一种合成反应级联，该级联采用组装后修饰反应来指导相间超分子复合物的分配。该系统由自组装的四嗪边缘Fe ^II ₈ L ₁₂立方体和马来酰亚胺官能化的Fe ^II ₄ L _6组成。四面体。降冰片二烯（NBD）作为触发级联反应的刺激物，从NBD的逆电子需求Diels-Alder反应与立方体的四嗪部分开始。该反应产生环戊二烯作为瞬时副产物，充当中继信号，随后与马来酰亚胺官能化的四面体进行狄尔斯-阿尔德反应。环辛炔可以通过胜过NBD作为初始触发来选择性抑制级联反应。用2-十八烷基NBD引发级联反应导致级联反应完成时四面体的选择性烷基化。C ₁₈标记的四面体的增加的亲脂性使该配合物进入非极性相，从而使其与最初不可分割的配合物混合物分离。