Exploring and controlling chemical reactions in compartments opens new platforms for designing bioinspired catalysts and energy-autonomous systems. Aqueous polymer networks or hydrogels serve as a perfect model for biological tissues, allowing systematic investigations of chemical transformations in compartments. Herein, we report the synthesis of a versatile, colloidal microgel catalyst containing covalently bound l-proline as an organocatalyst. The key finding of our work is that the catalytic activity can be tuned by adjusting the distribution of the organocatalyst in the microgel network as well as the properties of the solvent. We demonstrate that l-proline groups integrated into microgels enable the reaction of 4-nitrobenzaldehyde and cyclohexanone in a heterogeneous reaction mixture in which free l-proline is not active. By controlling the localization of the l-proline groups within the microgel network (core or corona), the rate of the aldol reaction in homogenous and heterogeneous reaction mixtures can be modulated. Furthermore, microgels with covalently attached catalysts can be recycled and reused in sequential catalytic runs without deterioration of the catalyst performance in terms of activity and selectivity. The internal structure of the microgel in heterogeneous reaction mixtures was studied by computer simulations.

中文翻译：

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通过隔室化提高的催化剂性能，例如胶态的I-脯氨酸改性的微凝胶催化剂。

探索和控制隔室中的化学反应为设计生物启发的催化剂和能量自主系统提供了新的平台。水性聚合物网络或水凝胶可作为生物组织的理想模型，可以对隔室中的化学转化进行系统的研究。在本文中，我们报道了一种通用的胶体微凝胶催化剂的合成，该催化剂包含共价键合的脯氨酸作为有机催化剂。我们工作的关键发现是，可以通过调节微凝胶网络中有机催化剂的分布以及溶剂的性质来调节催化活性。我们证明，整合到微凝胶中的l-脯氨酸基团使4-硝基苯甲醛和环己酮在异质反应混合物中反应，其中游离的l-脯氨酸没有活性。通过控制微凝胶网络（核或电晕）内l-脯氨酸基团的定位，可以调节均相和异相反应混合物中的羟醛反应速率。此外，具有共价连接的催化剂的微凝胶可以在连续的催化运行中再循环和再利用，而不会在活性和选择性方面降低催化剂的性能。通过计算机模拟研究了异质反应混合物中微凝胶的内部结构。具有共价连接的催化剂的微凝胶可以循环使用，并在连续的催化操作中重复使用，而不会降低催化剂的活性和选择性。通过计算机模拟研究了异质反应混合物中微凝胶的内部结构。具有共价连接的催化剂的微凝胶可以循环使用，并在连续的催化操作中重复使用，而不会降低催化剂的活性和选择性。通过计算机模拟研究了异质反应混合物中微凝胶的内部结构。