Jaiswal Amit K, Saha Priya, Jiang Julong, Suzuki Kimichi, Jasny Anna, Schmidt Bernd M, Maeda Satoshi, Hecht Stefan, Huang Chung-Yang Dennis
Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Kita 21, Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0021, Japan.
Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-8628, Japan.
J Am Chem Soc. 2024 Aug 7;146(31):21367-21376. doi: 10.1021/jacs.4c03543. Epub 2024 Jul 26.
The ability to correlate the structure of a molecule with its properties is the key to the rational and accelerated design of new functional compounds and materials. Taking photoswitches as an example, the thermal stability of the metastable state is a crucial property that dictates their application in molecular systems. Indigos have recently emerged as an attractive motif for designing photoswitchable molecules due to their red-light addressability, which can be advantageous in biomedical and material applications. The lack of synthetic techniques to derivatize the abundant parent dye and a thorough understanding of the impact of structural factors on the photochemical and thermal properties hinder broad applications of this emerging photoswitch class. Herein, we report an efficient copper-catalyzed indigo -arylation that enables the installation of a wide variety of aryl moieties carrying useful functional groups. The exclusive selectivity for monoarylation likely originates from a bimetallic cooperative mechanism through a binuclear copper-indigo intermediate. Functional -aryl--alkylindigos were prepared and shown to photoisomerize efficiently under red light. Moreover, this design allows for the modulation of thermal half-lives through -aryl substituents, while the -alkyl groups enable the independent attachment of functional moieties without affecting the photochromic properties. A strong correlation between the structure of the -aryl moiety and the thermal stability of the photogenerated -isomers was achieved by multivariate linear regression models obtained through a data-science workflow. This work thus builds an avenue leading to versatile red-light photoswitches and a general method for structure-property correlation that is expected to be broadly applicable to the design of photoresponsive molecules.
将分子结构与其性质相关联的能力是合理且加速设计新型功能化合物和材料的关键。以光开关为例，亚稳态的热稳定性是决定其在分子系统中应用的关键性质。由于靛蓝具有红光可寻址性，最近它已成为设计光开关分子的一个有吸引力的基序，这在生物医学和材料应用中可能具有优势。缺乏对丰富的母体染料进行衍生化的合成技术以及对结构因素对光化学和热性质影响的全面理解，阻碍了这类新兴光开关的广泛应用。在此，我们报道了一种高效的铜催化靛蓝芳基化反应，该反应能够引入各种带有有用官能团的芳基部分。单芳基化的专一选择性可能源于通过双核铜 - 靛蓝中间体的双金属协同机制。制备了功能化的芳基 - 烷基靛蓝，并证明其在红光下能有效地进行光异构化。此外，这种设计允许通过芳基取代基调节热半衰期，而烷基能够独立连接功能部分而不影响光致变色性质。通过数据科学工作流程获得的多元线性回归模型实现了芳基部分的结构与光生异构体的热稳定性之间的强相关性。因此，这项工作开辟了一条通往通用红光光开关的途径以及一种结构 - 性质相关性的通用方法，有望广泛应用于光响应分子的设计。
