Preparation of [ closo -CB 11 H 12 ] - by Dichlorocarbene Insertion Into [ nido -B 11 H 14 ] -
Preparation of [ closo -CB 11 H 12 ] - by Dichlorocarbene Insertion Into [ nido -B 11 H 14 ] -
复制标题
[ closo -CB 11 H 12 ] - 通过将二氯卡宾插入到 [ nido -B 11 H 14 ] - 中制备
DOI：
10.1135/cccc20011238
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发表时间：
2001
影响因子：
--
通讯作者：
J. Michl
中科院分区：
文献类型：
--
作者：
A. Franken;B. T. King;J. Rudolph;P. Rao;B. Noll;J. Michl
在强碱介质中，[nido-B11H14]-阴离子与卤仿物发生反应。脱氢生成[close - b11h11]2-是唯一观察到的与碘仿的反应。用氯仿和溴仿，通过插入二卤碳烯使笼膨胀。主要产物分别是[closo-CB11H12]-和[2-Br-closo-CB11H12]-阴离子。主要副产物是[closo-B11H11]2-阴离子，这是由原料脱氢产生的。经11B核磁共振鉴定，并经酸性水分解分离得到[nido-7-OH-B11H13]-阴离子。由于[nido-B11H14]-阴离子可以从NaBH4和BF3·Et2O中以50%的产率得到，它与氯仿和碱以40%的产率转化为[closo-CB11H12]-代表了一条有用的实验室途径，可以得到许多已知的但以前非常昂贵的[closo-CB11H12]-衍生物，这些衍生物因其极低的亲核性而受到高度重视。
In strongly basic media, the [nido-B11H14]- anion reacts with the haloforms. Dehydrogenation to [closo-B11H11]2- is the only reaction observed with iodoform. With chloroform and bromoform, the cage is expanded by dihalocarbene insertion. The dominant products are the [closo-CB11H12]- and the [2-Br-closo-CB11H12]- anion, respectively. The chief side product is the [closo-B11H11]2- anion, which results from dehydrogenation of the starting material. It was identified by 11B NMR spectroscopy and isolated after acidic aqueous workup in the form of the [nido-7-OH-B11H13]- anion. Since the starting [nido-B11H14]- anion is available from NaBH4 and BF3·Et2O in 50% yield, its conversion to [closo-CB11H12]- with chloroform and base in a 40% yield represents a useful laboratory route to the numerous known but previously very expensive derivatives of [closo-CB11H12]-, highly prized for their very low nucleophilicity.