Catalytic Generation of Borenium Ions by Cooperative B–H Bond Activation: The Elusive Direct Electrophilic Borylation of Nitrogen Heterocycles with Pinacolborane
作者:Timo Stahl、Kristine Müther、Yasuhiro Ohki、Kazuyuki Tatsumi、Martin Oestreich
DOI:10.1021/ja405925w
日期:2013.7.31
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
典型硼烷的 BH 键被束缚的钌 (II) 硫醇盐络合物的极性 Ru-S 键异裂,提供氢化钌 (II) 和硼离子,并与硫原子发生配价相互作用。这些稳定的加合物经过光谱表征,在一种情况下,BH 键激活步骤在晶体学上得到验证,这是 σ 键复分解的快照。源自 9-硼双环 [3.3.1] 壬烷二聚体 [(9-BBN)2]、频哪醇硼烷 (pinBH) 和儿茶酚硼烷 (catBH) 的硼离子允许吲哚的亲电芳香取代。针对各种氮杂环进一步阐述了前所未有的 pinB 阳离子亲电硼酸化。