Selective Synthesis of Stannoles by 1,1‐Carboboration of Bis(trimethylsilylethynyl)tin Compounds Using Weakly and Strongly Electrophilic Triorganoboranes: Characterization of a Zwitterionic Intermediate
作者:Bernd Wrackmeyer、Peter Thoma、Simone Marx、Tobias Bauer、Rhett Kempe
DOI:10.1002/ejic.201400028
日期:2014.4
one case, using the strongly electrophilic B(C6F5)3, a zwitterionic intermediate was isolated and structurally characterized by X-ray diffraction analysis. The question of reversibility of the 1,1-carboboration is addressed. Multinuclear magnetic resonance spectroscopy (1H, 11B, 13C, 19F, 29Si, 119Sn NMR) was used to characterize the intermediates and the stannoles as the final products. Some of the NMR
三有机硼烷 BEt3、BPh3 和 B(C6F5)3 可以与双(三甲基甲硅烷基乙炔基)二有机锡化合物 [R12Sn(C≡C–SiMe3)2; R12 = –(CH2)5– (a), R1 = nBu (b), nOct (c), Ph (d)] 以选择性和定量地给出锡醇。反应在两个连续步骤(分子间和分子内)中通过 1,1-碳硼化进行,中间体通过 NMR 光谱检测。在一种情况下,使用强亲电性 B(C6F5)3,分离出两性离子中间体,并通过 X 射线衍射分析对其进行结构表征。解决了 1,1-碳硼化的可逆性问题。多核磁共振波谱(1H、11B、13C、19F、29Si、119Sn NMR)用于表征中间体和作为最终产物的锡醇。一些核磁共振参数(11B、13C、