Bio-inspired creation of heterogeneous reaction vessels via polymerization of supramolecular ion pair

Abstract

Precise control of the outer-sphere environment around the active sites of heterogeneous catalysts to modulate the catalytic outcomes has long been a challenge. Here, we demonstrate how this can be fulfilled by encapsulating catalytic components into supramolecular capsules, used as building blocks for materials synthesis, whereby the microenvironment of each active site is tuned by the assembled wall. Specifically, using a cationic template equipped with a polymerizable functionality, anionic ligands can be encapsulated by ion pair-directed supramolecular assembly, followed by construction into porous frameworks. The hydrophilic ionic wall enables reactions to be achieved in water that usually requires organic solvents and also facilitates the enrichment of the substrate into the hydrophobic pocket, leading to superior catalytic performances as demonstrated by the industrially relevant hydroformylation. Remarkably, the formation of the supramolecular assembly and catalyst encapsulation further engenders reaction selectivity, which reaches an even greater extent after construction of the porous framework.

Reusable Catalysts for Hydroformylation‐Based Reactions

“…Dong et al [113] described a supramolecular assembly as a building unit in the creation of catalytically active porous frameworks (Figure 19). The quaternary phosphonium moiety was chosen as cationic template, given its chemical stability, amenable synthesis, along with easy-to-get properties of anionic ligands and construct the resulting supramolecular assemblies into porous frameworks.…”

Progress in Application of Organic Polymers Supported Rhodium Catalysts in Hydroformylation

“…在 Rh/CPOL- 2018 年, 丁云杰和严丽课题组 [37] 将乙烯基 Biphenphos 和乙烯基的三苯基亚磷酸酯配体聚合得到 CPOL-BP&P(OPh) 3 [39] . 首先合成了以联萘为骨架的乙 烯基亚磷酸酰胺单体, 并与乙烯基三苯基膦聚合得到 POL-BINAPa&PPh 3 (Scheme 23) [40] ; 该聚合物与 Rh-(acac)(CO) [41] 发展的离 子型多空聚合物, 可以有效地解决该类问题. 首先将阳 离子的 4-乙烯基苄基乙烯基三苯基膦与阴离子的磺酸 基膦配体结合; 进一步在 AIBN 的催化下聚合乙烯基官 能团得到离子型多孔有机膦配体聚合物.…”

“…首先将阳 离子的 4-乙烯基苄基乙烯基三苯基膦与阴离子的磺酸 基膦配体结合; 进一步在 AIBN 的催化下聚合乙烯基官 能团得到离子型多孔有机膦配体聚合物. 通过嵌入不同 的阴离子配体可以分别得到 PSA-PPh 3 和 PSA-Xantphos, 再负载铑金属后得到相应的催化剂(Scheme 26) [41] . 该 类催化剂具有两亲性, 不仅具有亲水性, 而且与烯烃也 具 有 很 好 的 相 容 性 .…”

Exploration of Porous Organic Polymers as a Platform for Biomimetic Catalysis

“…借鉴酶的分子环境, 利用离子对组装的方法 将乙烯基功能化的阳离子模板(季鏻盐)和阴离子配体 (Xantphos)组装, 得到外层亲水、 内层疏水的限域反应腔 的超分子结构基元(图 6). 这种设计可显著提高醛的区 域选择性, 所得到的多孔超分子聚合物负载 Rh 之后, 在 1-辛烯氢甲酰化反应中直链醛与支链醛的比例较未 修饰的配体体系提升了 16 倍, 产物壬醛的正异构之比 达到 40 [14] . 这种策略不仅解决了配体固载后活性降低的问题, 还能有效提高催化中心的稳定性.…”