Design and Application of Novel, Visible-Light Acridinium-type Organophotocatalysts

新型可见光吖啶类有机光催化剂的设计与应用

• 批准号: 286725608
• 负责人: Professorin Dr. Olga Garcia Mancheno
• 金额: --
• 依托单位: Organisch-Chemisches Institut
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/286725608?language=en
• 关键词: Design; Application; Novel; Visible; Light

This project focusses on the design of novel acridinium-based structures as organophotocatalysts with improved oxidative and catalytic properties in their exited state for the development of valuable oxidative photocatalysis. Visible light photoredox catalysis has arisen as a powerful synthetic tool, offering access to unique reactivities. Besides transition-metal photosensitizers, organic dyes have recently been attracted great attention as photoredox catalysts, from which acridinium salts shine as one of the most powerful organophotocatalyst-type oxidants. However, their intrinsic instability and synthetic accessibility limit the structures to C9-aryl substituted species. In this project, new synthetic methods, including novel oxidative C-H functionalization approaches, to acridinium salts bearing C9-amide and amide-isosteric heterocycles will be developed. We have recently demonstrated that related C9-imide acridinium salts present enhanced photoactivities than standard C9-mesityl acridinium salts. However, their substitution pattern is constrained for which the proposed methods and structures will overcome the current tuneability issues. This project also aims at a better understanding of the photophysical properties and performance of the proposed new catalysts in order to identify improved highly active structures. The information obtained will be used to re-design new catalysts, whose activity will be evaluated in challenging visible light photocatalytic reactions, such as hydrofunctionalization of to date still highly demanding olefinic substrates, desilylative coupling reactions involving C(sp2)-Si bonds or selective radical cyclizations towards valuable heterocycles.

本项目致力于设计一种新型结构的有机光催化剂，在其存在状态下具有更好的氧化和催化性能，以开发有价值的氧化光催化。可见光光氧化还原催化作为一种强大的合成工具已经出现，它提供了获得独特反应活性的途径。除了过渡金属光敏剂外，有机染料作为光氧化还原催化剂近年来也引起了人们的极大关注，从这些有机染料中，吖啶盐成为最有效的有机光催化型氧化剂之一。然而，它们的内在不稳定性和合成的可获得性将结构限制在C9-芳基取代物种上。在这个项目中，将开发新的合成方法，包括新的氧化C-H官能化方法，以合成含C9-酰胺和酰胺-异构体杂环的吖啶盐。我们最近已经证明了相关的C9-酰亚胺吖啶盐表现出比标准的C9-甲基吖啶盐更强的光活性。然而，它们的替换模式是受限的，所提出的方法和结构将克服当前的可调性问题。该项目还旨在更好地了解所建议的新催化剂的光物理性质和性能，以便确定改进的高活性结构。所获得的信息将被用于重新设计新的催化剂，其活性将在具有挑战性的可见光催化反应中进行评估，例如迄今仍要求很高的烯烃底物的氢化官能化，涉及C(Sp2)-Si键的脱硅偶联反应，或选择性地向有价值的杂环进行自由基环化。