Körte Leif A, Warner Robin, Vishnevskiy Yury V, Neumann Beate, Stammler Hans-Georg, Mitzel Norbert W
Bielefeld University, Faculty of Chemistry, Chair of Inorganic and Structural Chemistry, Centre for Molecular Materials CM2, Universitätsstraße 25, 33615 Bielefeld, Germany.
Dalton Trans. 2015 Jun 7;44(21):9992-10002. doi: 10.1039/c5dt01068c.
Deprotonation of the methylpyridines 2,6-lutidine, 2-picoline, 4-dimethylamino-2,6-dimethylpyridine as well as 2,6-dimethyl-4-(piperidine-1-yl)pyridine with n-butyllithium or n-butyllithium/KO-t-Bu at the methyl positions led to the corresponding organolithium or -potassium compounds. Treatment with ClB(C6F5)2 resulted in formation of the 2-borylmethylpyridines py-CH2-B(C6F5)2. They are monomeric and form intramolecular B-N bonds and four-membered rings. A short intramolecular B-N distance was observed in the crystal structure of the dimethylamino-functionalized derivative and proposed to be responsible for the low reactivity of the products towards hydrogen, thf, acetonitrile and CO2. Hydroboration of 6-tert-butyl-2-but-4'-enylpyridine with HB(C6F5)2 led to the corresponding hydroboration product t-Bu-py-(CH2)4-B(C6F5)2 which shows no intramolecular B-N bond formation due to steric crowding. H/D-scrambling experiments with a H2/D2 mixture revealed its reactivity towards hydrogen.
用正丁基锂或正丁基锂/叔丁醇钾在甲基吡啶（2,6 - 二甲基吡啶、2 - 甲基吡啶、4 - 二甲基氨基 - 2,6 - 二甲基吡啶以及2,6 - 二甲基 - 4 -（哌啶 - 1 - 基）吡啶）的甲基位置进行去质子化反应，生成了相应的有机锂或有机钾化合物。用ClB(C6F5)2处理后得到了2 - 硼甲基吡啶py - CH2 - B(C6F5)2。它们是单体，形成分子内B - N键和四元环。在二甲基氨基官能化衍生物的晶体结构中观察到较短的分子内B - N距离，这被认为是产物对氢气、四氢呋喃、乙腈和二氧化碳反应活性较低的原因。用HB(C6F5)2对6 - 叔丁基 - 2 - 丁 - 4'- 烯基吡啶进行硼氢化反应，得到了相应的硼氢化产物t - Bu - py - (CH2)4 - B(C6F5)2，由于空间位阻，该产物未形成分子内B - N键。用H2/D2混合物进行H/D交换实验揭示了其对氢气的反应活性。
