Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, 60438, Frankfurt am Main, Germany.
Angew Chem Int Ed Engl. 2017 May 8;56(20):5588-5592. doi: 10.1002/anie.201701591. Epub 2017 Apr 12.
Ten examples of unsymmetrically benzannulated, boron-doped polycyclic aromatic hydrocarbons (B-PAHs) were prepared by a one-pot protocol using 4,5-dichloro-1,2-bis(trimethylsilyl)benzene (1), BBr , and selected PAHs-among them anthracene, benzo[a]pyrene, biphenylene, and fluoranthene. After mesitylation at the boron centers, the resulting air- and water-stable products were investigated by H/ B{ H}/ C{ H} NMR spectroscopy, X-ray crystallography, cyclic voltammetry, and UV/Vis absorption/emission spectroscopy. The experiments were augmented by DFT calculations. Most of the B-PAHs are brightly luminescent (Φ up to 90 %) and undergo reversible reduction at moderate half-wave potentials. The two chloro substituents of 1 are not only mandatory for accomplishing efficient diborylation, but can subsequently be used for Stille-type coupling reactions to introduce 2-thienyl moieties. Alternatively, Cl/H exchange is achievable with HSiEt in a quantitative, Pd-catalyzed transformation.
通过一锅法使用 4,5-二氯-1,2-双（三甲基甲硅烷基）苯（1）、BBr 和选定的多环芳烃（包括蒽、苯并[a]芘、联苯和荧蒽）制备了十个不对称苯并环化的硼掺杂多环芳烃（B-PAHs）。在硼中心进行甲硅烷基化后，通过 1 H/{ 1} H、 13 C/{ 1} H、X 射线晶体学、循环伏安法和紫外/可见吸收/发射光谱法研究了所得空气和水稳定的产物。实验通过 DFT 计算得到了补充。大多数 B-PAHs 具有很高的发光效率（Φ高达 90%），并在适度的半波电位下发生可逆还原。1 的两个氯取代基不仅是实现高效双硼化所必需的，而且可以随后用于 Stille 型偶联反应以引入 2-噻吩基部分。或者，可以通过 HSiEt3 在定量、Pd 催化的转化中进行 Cl/H 交换。
