Dissipative self-assembly of a proline catalyst for temporal regulation of the aldol reaction
Dissipative self-assembly of a proline catalyst for temporal regulation of the aldol reaction
复制标题
脯氨酸催化剂的耗散自组装用于羟醛反应的时间调节
DOI：
10.1039/d2nr03991e
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发表时间：
2022
期刊：
影响因子：
6.7
通讯作者：
Parquette, Jon R.
中科院分区：
文献类型：
--
作者：
Reardon, Thomas J.;Na, Baichuan;Parquette, Jon R.
生物系统中化学反应性的时空调节允许代谢反应网络在相同的细胞环境中发生。反应性的精确控制通常是由非平衡结构介导的，这些结构只有在燃料存在时才能保持功能，以保持更高的能量，活性状态。超分子化学的一个重要目标是开发接近生物机械复杂性的功能性能量耗散系统。挑战在于创建将促进分子达到更高能量、组装状态所需的能量消耗与功能特性（如催化活性）相结合的策略。在这项工作中，我们证明了组装的螺吡喃（SP）二肽（1）瞬时促进脯氨酸催化的羟醛缩合反应在水中时，可见光作为燃料。在光照下，由于单体的O-质子化（1-MCH+）mercury形式光异构化为螺吡喃（1-SP）状态，其迅速组装成能够在水中催化羟醛缩合反应的纳米片，从1中出现瞬时催化活性。当光源被移除时，热异构化为更稳定的MCH+形式导致纳米片解离成无催化活性的单体状态。在这些条件下，通过打开和关闭光源，可以反复激活和失活羟醛缩合反应。
The spatiotemporal regulation of chemical reactivity in biological systems permits a network of metabolic reactions to take place within the same cellular environment. The exquisite control of reactivity is often mediated by out-of-equilibrium structures that remain functional only as long as fuel is present to maintain the higher energy, active state. An important goal in supramolecular chemistry aims to develop functional, energy dissipating systems that approach the sophistication of biological machinery. The challenge is to create strategies that couple the energy consumption needed to promote a molecule to a higher energy, assembled state to a functional property such as catalytic activity. In this work, we demonstrated that the assembly of a spiropyran (SP) dipeptide (1) transiently promoted the proline-catalyzed aldol reaction in water when visible light was present as fuel. The transient catalytic activity emerged from 1 under light illumination due to the photoisomerization of the monomeric, O-protonated (1-MCH+) merocyanine form to the spiropyran (1-SP) state, which rapidly assembled into nanosheets capable of catalyzing the aldol reaction in water. When the light source was removed, thermal isomerization to the more stable MCH+ form caused the nanosheets to dissociate into a catalytically inactive, monomeric state. Under these conditions, the aldol reaction could be repeatedly activated and deactivated by switching the light source on and off.