Photothermal Catalysis: Using light to thermally generate reactive intermediates with temporal and spatial control

光热催化：利用光热生成具有时间和空间控制的反应中间体

基本信息

批准号：
10713733
负责人：
Erin Stache
金额：
$ 40.58万
依托单位：
PRINCETON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2028-08-31
项目状态：
未结题

项目摘要

Project Summary Photon-driven processes have emerged as a powerful tool for achieving challenging bond cleavage and bond formation. Photocatalysis offers the benefit of temporal and spatial control with low energy light, which has been widely advantageous for efficiently building molecular complexity from simple starting materials. The judicious choice of photocatalysts enables the precision of reactivity that is rarely achieved with other forms of catalysis and heating. An underused area of photocatalysis is photothermal conversion. Irradiation of specific nanoparticles or dyes with visible light creates intense thermal gradients in a photothermal conversion process. In contrast to bulk heating, where the temperature remains uniform across a reaction medium, substrates would only experience thermal energy within a few nanometers of excitation under temporal heating. Consequently, this process would use irradiation to drive chemical processes at high temperatures with temporal and spatial control. Spatial control enables the selective formation of highly reactive species without competing bimolecular side reactions. The proposed research comprises three fundamental projects exploring the use of photothermal catalysis to enable the synthesis of complex molecules using visible light irradiation. First, high-temperature thermal rearrangements will be achieved using carbon-based nanoparticles and visible light irradiation under mild conditions. This strategy will enable the synthesis of complex products without thermal decomposition generally associated with bulk thermolysis. Additionally, the identification of various photothermal agents and synthetic elaborations will generate more efficient catalysts. In the second project, photothermal heating will generate carbon-centered radicals through C–C bond homolysis. Intercepting these highly reactive intermediates will forge new C–C bonds in ring expansion reactions, in intramolecular cyclizations. Specific photothermal agent design will enable intermolecular ring expansions to build molecular complexity. In a third project, the C–C bond homolysis reactions identified in project two will be used in dynamic kinetic resolutions for atom economical synthesis of enantioenriched pharmaceutical compounds. Emulsions will confine thermal gradients to within micelles enabling the coupling of thermal epimerization reactions with highly selective enzymatic reactions. Combined, these three projects will develop an understanding of photothermal catalysis and the effect of light and intensity on generation of thermal gradients. A thorough understanding of how these thermal gradients can be leveraged for high temperature reactions with the spatial and temporal control of visible light will enable new synthetic bond disconnections previously unrealized.

项目摘要光子驱动的过程已成为实现挑战债券裂解和的强大工具债券形成。光催化提供了具有低能光的临时和空间控制的好处，对于简单的起始材料的有效构建分子复杂性是广泛有利的。这明智的光催化剂选择可以使反应性的精度很少获得催化和加热。光催化的未充分利用区域是光热转化。特定的辐照具有可见光的纳米颗粒或染料会在光热转化过程中产生强烈的热梯度。与散装加热相反，在反应介质中温度保持均匀，底物将仅在临时加热下的几种兴奋剂中体验热能。最后，此过程将使用辐照以暂时和空间的高温驱动化学过程控制。空间控制能够选择性形成高反应性物种，而无需竞争双重分子侧面反应。拟议的研究组成了三个基本项目，探索了光热催化的使用使用可见光照射能够合成复杂分子。首先，高温热将使用基于碳的纳米颗粒和中间的可见光照射来重新排列状况。该策略将使复杂产物的合成无热分解与散装热解有关。此外，鉴定各种光热剂和合成阐述将产生更有效的催化剂。在第二个项目中，光热加热将产生通过C-C键同伊分析以碳为中心的自由基。拦截这些高度反应性的中间体将锻造环内循环中的环膨胀反应中的新C – C键。特定的光热剂设计将实现分子间环的扩展以构建分子复杂性。在第三个项目中，C -C债券项目第二个项目中确定的均解反应将用于原子经济的动态动力学分辨率映射药物化合物的合成。乳液会将热梯度局限于内部胶束可以使热发作反应与高选择性酶促反应偶联。结合在一起，这三个项目将对光热催化和光的影响有所了解和热梯度产生的强度。对这些热梯度的透彻了解通过对可见光的空间和临时控制，可以利用高温反应来实现新的合成键断开以前未实现。