acid–base adduct formation between N-heterocyclic silylenes and silyl arenium ions. They were isolated in high yields as their [B(C6F5)4]− salts. These salts are stable at room temperature and were characterized by NMR spectroscopy supported by the results of density functional computations of molecular structures and NMR chemicalshifts. NICScalculations suggest for the imidazolium ions 7 only a modest
2-硅咪唑鎓N杂环甲硅烷基和甲硅烷基芳烃离子之间的路易斯酸碱加成反应合成了7号离子和2个硅咪唑啉鎓离子8号离子。以[B(C 6 F 5)4 ] -盐的形式高收率分离。这些盐在室温下稳定,并通过NMR光谱进行表征,并由分子结构的密度泛函计算和NMR化学位移的结果所支持。NICS计算表明,对于咪唑鎓离子7而言,其芳香度中等。尽管使用的取代基R 1和R 2庞大,甲硅烷基离子7和8表现为经典的路易斯对,并且没有显示出意外的反应性。
Reaction of Dihalodiboranes(4) with a N‐Heterocyclic Silylene: Facile Construction of 1‐Aryl‐2‐Silyl‐1,2‐Diboraindanes
作者:Holger Braunschweig、Tobias Brückner、Andrea Deißenberger、Rian D. Dewhurst、Annika Gackstatter、Annalena Gärtner、Alexander Hofmann、Thomas Kupfer、Dominic Prieschl、Torsten Thiess、Sunewang Rixin Wang
DOI:10.1002/chem.201702377
日期:2017.7.18
N‐heterocyclic silylene (NHSi) to generate NHSi adducts of 1‐aryl‐2‐silyl‐1,2‐diboraindanes, as was confirmed by X‐ray crystallography, featuring the functionalization of both B−X (X=halogen) bonds and a sp3‐ or sp2‐C−H bond under mild conditions. Coordination of a third NHSi to the proposed 1,1‐diaryl‐2,2‐disilyldiborane(4) intermediates, generated by a twofold B−X insertion, may be crucial for the C−H borylation