Department of Materials Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 1, 52-8552, Japan.
Laboratorium für Organische Chemie, ETH Zurich, Vladimir-Prelog-Weg 3, 8093, Zurich, Switzerland.
Angew Chem Int Ed Engl. 2018 Mar 26;57(14):3552-3577. doi: 10.1002/anie.201711605. Epub 2018 Feb 22.
The [2+2] cycloaddition-retroelectrocyclization (CA-RE) reaction between electron-rich alkynes and electron-deficient alkenes is an efficient procedure to create nonplanar donor-acceptor (D-A) chromophores in both molecular and polymeric platforms. They feature attractive properties including intramolecular charge-transfer (ICT) bands, nonlinear optical properties, and redox activities for use in next-generation electronic and optoelectronic devices. This Review summarizes the development of the CA-RE reaction, starting from the initial reports with organometallic compounds to the extension to purely organic systems. The structural requirements for rapid, high-yielding transformations with true click chemistry character are illustrated by examples that include the broad alkyne and alkene substitution modes. The CA-RE click reaction has been successfully applied to polymer synthesis, with the resulting polymeric push-pull chromophores finding many interesting applications.
[2+2]环加成-反电环化（CA-RE）反应是一种有效的方法，可在分子和聚合物平台中创建非平面给体-受体（D-A）发色团，其中电子富炔和亲电烯烃反应。它们具有吸引人的性质，包括分子内电荷转移（ICT）带、非线性光学性质和氧化还原活性，可用于下一代电子和光电子设备。这篇综述总结了 CA-RE 反应的发展，从最初的有机金属化合物报告到扩展到纯有机体系。通过包括广泛的炔烃和烯烃取代模式在内的实例说明了具有真正点击化学反应特征的快速、高产转化的结构要求。CA-RE 点击反应已成功应用于聚合物合成，所得的聚合物推-拉发色团具有许多有趣的应用。
