Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.
Molecules. 2020 Jun 22;25(12):2875. doi: 10.3390/molecules25122875.
The reactions of electron-rich organosilicon compounds 1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene (), 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene (), and 1,1'-bis(trimethylsilyl)-1,1'-dihydro-4,4'-bipyridine () with -amino and -aryl dihaloboranes afforded a series of novel B=N-bond-containing compounds - and . The B=N rotational barriers of (>71.56 kJ/mol), (58.79 kJ/mol), and (58.65 kJ/mol) were determined by variable-temperature H-NMR spectroscopy, thus reflecting different degrees of B=N double bond character in the corresponding compounds. In addition, ring external olefin isomers were obtained by a reaction between and DurBBr. All obtained B=N-containing products were characterized by multinuclear NMR spectroscopy. Compounds , , , , and were also characterized by single-crystal X-ray diffraction analysis.
富电子有机硅化合物 1,4-双(三甲基甲硅烷基)-1,4-二氮杂-2,5-环己二烯 (), 2,3,5,6-四甲基-1,4-双(三甲基甲硅烷基)-1,4-二氮杂-2,5-环己二烯 (), 和 1,1'-双(三甲基甲硅烷基)-1,1'-二氢-4,4'-联吡啶 () 与 -氨基和 -芳基二卤化硼反应，得到了一系列新型的含 B=N 键的化合物 - 和 。通过变温 H-NMR 光谱法测定了 B=N 旋转势垒 (>71.56 kJ/mol)、 (58.79 kJ/mol) 和 (58.65 kJ/mol)，反映了相应化合物中 B=N 双键特征的不同程度。此外，通过与 DurBBr 的反应得到了环外烯烃异构体 。通过多核 NMR 光谱对所有获得的含 B=N 的产物进行了表征。还通过单晶 X 射线衍射分析对化合物,,,,, 和 进行了表征。
