Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, 60438, Frankfurt am Main, Germany.
Angew Chem Int Ed Engl. 2017 Jun 19;56(26):7546-7550. doi: 10.1002/anie.201702393. Epub 2017 May 22.
Deprotonation of the doubly arylene-bridged diborane(6) derivative 1H with (Me Si) CLi or (Me Si) NK gives the B-B σ-bonded species M[1H] in essentially quantitative yields (THF, room temperature; M=Li, K, arylene=4,4'-di-tert-butyl-2,2'-biphenylylene). With nBuLi as the base, the yield of Li[1H] drops to 20 % and the 1,1-bis(9-borafluorenyl)butane Li[2H] is formed as a side product (30 %). In addition to the 1,1-butanediyl fragment, the two boron atoms of Li[2H] are linked by a μ-H bridge. In the closely related molecule Li[3H], the corresponding μ-H atom can be abstracted with (Me Si) CLi to afford the B-B-bonded conjugated base Li [3] (THF, 150 °C; 15 %). Li[1H] and Li[2H] were characterized by NMR spectroscopy and X-ray crystallography.
用(Me Si) CLi 或(Me Si) NK 将双芳基桥联二硼烷(6)衍生物 1H 去质子化，可在定量收率下（THF，室温；M=Li，K，芳基=4,4'-二叔丁基-2,2'-联苯）得到基本上为 B-B σ键合的物种 M[1H]。用 nBuLi 作为碱，Li[1H]的产率降至 20%，并且形成了 1,1-双(9-硼杂芴基)丁烷 Li[2H]作为副产物（30%）。除了 1,1-丁二基片段外，Li[2H]的两个硼原子通过μ-H 桥连接。在密切相关的分子 Li[3H]中，可以用(Me Si) CLi 提取相应的μ-H 原子，得到 B-B 键合的共轭碱 Li[3]（THF，150°C；15%）。Li[1H]和 Li[2H]通过 NMR 光谱和 X 射线晶体学进行了表征。
