Pentaborane(9) derivatives. II. Synthesis of di- and trisubstituted methyl-, methylchloro-, and methylbromopentaboranes. Detailed nuclear magnetic resonance studies
Pentaborane(9) derivatives. II. Synthesis of di- and trisubstituted methyl-, methylchloro-, and methylbromopentaboranes. Detailed nuclear magnetic resonance studies
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五硼烷(9)衍生物。
DOI：
10.1021/ic50088a028
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发表时间：
1970
影响因子：
4.6
通讯作者：
J. B. Leach
中科院分区：
文献类型：
--
作者：
P. M. Tucker;T. Onak;J. B. Leach
CHaBsHr，2-Cl-3-CH3BsH7，2-Cl-4-CH3BsH7，1，2，3-（CH3）3B，-，He，2，3，4-（CH，）。波黑，2-Cl-1，3-（CH3）2B5H6，2-Cl-1，4-（CH3）2-B5H6，2-Cl-3，4-（CH3）2B5H6，3-Cl-2，4-（CH3）2B.; H6和1-C1-2，3-（CH 3）2B 5 H5。这些和一些以前报道的戊硼烷衍生物的和“B核磁共振谱完全指定。测定了取代基对邻位、邻位和反式硼的化学位移的影响，发现对多取代戊硼烷有加和作用。桥氢的化学位移在不同的环境中也存在加和关系。远程耦合（ca. 6-7 Hz）之间的顶点硼和1-甲基衍生物的连接的甲基氢似乎是一个普遍存在。2-甲基戊硼烷的Friedel-Crafts烷基化除了产生预期的1，2-二甲基戊硼烷之外还产生戊硼烷的氯化衍生物。多取代五硼烷的碱催化重排研究为“最小原子运动”机制提供了实验支持。
CHaBsHr, 2-Cl-3-CHsBsH7, 2-C1-4-CH3BsH7, l, 2, 3-(CHa) 3B,-, He, 2, 3, 4-(CH,). BiH., 2-Cl-l, 3-(CH3) 2B5H6, 2-Cl-l, 4-(CH3) 2-B5H6, 2-Cl-3, 4-(CH3) 2B5H6, 3-Cl-2, 4-(CH3) 2B.; H6, and 1-C1-2, 3-(CH3) 2B5Hs. The and “B nmr spectra of these and of some previously reported pentaborane derivatives are totally assigned. Substituent effects on the chemical shifts of con-tiguous, neighboring, and trans borons havebeen determined and are found to be additive for polysubstituted pentaboranes. An additivity relationship has also been found for the chemical shifts of bridge hydrogens in differing environments. Long-range coupling (ca. 6-7 Hz) between the apex boron and the attached methyl hydrogen of 1-methyl derivatives appears to be a general occurrence. A Friedel-Crafts alkylation of 2-methylpentaborane produces chlorinated derivatives of pentaborane in addition to the expected 1, 2-dimethylpentaborane. Base-catalyzed rearrangement studies on polysubstituted penta-boranes lend experimental support to a “minimum atomic motion’’mechanism.