Bioinspired selective heterogeneous organic photoredox catalysis

项目摘要PI：Deria，Pravas 光氧化还原反应为开发新药合成路线提供了独特的机会 通过SP3、C-H和C-X(X)形成C-C键而无法获得的发现 =卤素)激活。然而，目前使用金属(如Ru)的方法 或显式有机光敏剂(PS)需要两个关键挑战 与实现原子经济立体选择性有关(对生物医学活动至关重要) 以及易分离和可回收(大规模合成所需)。异质 具有类似酶的选择性的光催化剂是必需的，但仍然难以捉摸--主要是因为 与扩散相关的挑战，与热激活转化不同，反应物， 底物和手性诱导基团需要在短时间内接近(通常是纳米到... 微秒)时间刻度。我们建议用多孔性晶体解决当前的挑战 分子骨架作为光敏剂在其明确定义的范围内驱动选择性催化 孔洞。 讨论了与扩散相关的挑战和相关的光物理要求 在某些晶体金属有机骨架(MOF)中，数十个光活性连接体 作为捕光天线。光激发能量转移(也被视为分子 激子迁移)，沿着分子扩散的优选方向，可以被调谐并 准备好了。高效的优先激子迁移率可以利用PS扩散所需的需求 刺激底物。因此，这一领域的提议将开创新的财政部组成，包括： (I)控制光电性能作为框架结构的函数，这是 多相光催化氧化还原--(II)阐明MOF光催化的共性 反应和产品可获得性，以及(Iii)揭示 立体选择性变换。具有分子尺度的孔隙率和可调性的MOF 为基础光化学提供可扩展、定义良好的模块化异构平台 事态的发展。结合分子组装收获光驱动的方法 在其受限的、但选择性的多孔洞内的光化学转化将提供 可转让和潜在变革性的基础知识，用于开发可回收和 用于发现救命药物的选择性多相光催化剂。 项目摘要/摘要

Project Summary PI: Deria, Pravas Photoredox reactions offer unique opportunities to develop synthetic routes for new drug discoveries that are otherwise unattainable via C-C bond formation through sp3 C-H and C-X (X = halogen) activations. However, current methodologies that employ metallic (such as ruthenium and iridium) complexes or explicit organic photosensitizer (PS) entail two critical challenges relevant to the implementation of atom-economic stereoselectivity (critical for biomedical activity) and easy separability and recyclability (required for large-scale syntheses). Heterogeneous photocatalysts with enzyme-like selectivity are required but remained elusive –mainly due to diffusion-related challenges where, unlike thermally activated transformations, the reactants, substrates, and chirality-inducing groups need to come close within a short (typically nano-to- microsecond) timescale. We propose to address the incumbent challenges with porous crystalline molecular frameworks as a photosensitizer to drive selective catalysis within their well-defined pore cavities. The diffusion-related challenge and relevant photophysical requirements are addressed within certain crystalline metal–organic frameworks (MOFs) where tens of photoactive linkers serve as light-harvesting antennas. The photoexcited energy transfer (also treated as molecular exciton migration), along the preferred direction of the molecular diffusion, can be tuned and primed. Efficient preferential exciton mobility can leverage the need for PS diffusion required to excite the substrates. Therefore, this AREA proposal will pioneer novel MOF compositions that: (i) control optoelectronic properties as a function of framework structure critically required for heterogeneous photoredox catalysis, (ii) elucidate the generality of the MOF photocatalytic reaction and products accessibility, and (iii) unveil the critical microenvironment needed for stereoselective transformations. Endowed with molecular-scale porosity and tunability, MOFs provide scalable, well-defined, modular heterogeneous platforms for fundamental photochemical developments. The methods, combining molecular assemblies to harvest light driving photochemical transformations within its confined, yet selective porous cavity, will provide transferrable and potentially transformative fundamental knowledge for developing recyclable and selective heterogeneous photocatalysts for the discovery of life-saving drugs. Project Summary/Abstract