Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany.
J Am Chem Soc. 2013 Jul 31;135(30):10978-81. doi: 10.1021/ja405925w. Epub 2013 Jul 17.
The B-H bond of typical boranes is heterolytically split by the polar Ru-S bond of a tethered ruthenium(II) thiolate complex, affording a ruthenium(II) hydride and borenium ions with a dative interaction with the sulfur atom. These stable adducts were spectroscopically characterized, and in one case, the B-H bond activation step was crystallographically verified, a snapshot of the σ-bond metathesis. The borenium ions derived from 9-borabicyclo[3.3.1]nonane dimer [(9-BBN)2], pinacolborane (pinBH), and catecholborane (catBH) allowed for electrophilic aromatic substitution of indoles. The unprecedented electrophilic borylation with the pinB cation was further elaborated for various nitrogen heterocycles.
典型的硼烷的 B-H 键被桥连的钌(II)硫醇配合物的极性 Ru-S 键异裂，生成一个钌(II)氢化物和带 d 键的硼翁离子，与硫原子配位。这些稳定的加合物通过光谱学进行了表征，在一种情况下，B-H 键活化步骤通过晶体学得到了验证，这是 σ-键交换反应的一个快照。衍生自 9-硼双环[3.3.1]壬烷二聚体[(9-BBN)2]、频哪醇硼烷(pinBH)和邻苯二硼烷(catBH)的硼翁离子允许吲哚进行亲电芳香取代反应。带有 pinB 阳离子的前所未有的亲电硼化反应进一步用于各种氮杂环。
