Quantitative Stereochemical Analysis of a Reagent That Exhibits Asymmetric Amplification, B-Chlorodiisopinocampheylborane (Dip-Cl)
Quantitative Stereochemical Analysis of a Reagent That Exhibits Asymmetric Amplification, B-Chlorodiisopinocampheylborane (Dip-Cl)
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对具有不对称扩增的试剂 B-氯二异松蒎基硼烷 (Dip-Cl) 进行定量立体化学分析
DOI：
10.1021/ja000158j
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发表时间：
2000
影响因子：
15
通讯作者：
J. Sowa
中科院分区：
文献类型：
--
作者：
C. Moeder;and Mark A. Whitener;J. Sowa
我们发现b -氯二异戊二苯硼烷（Dip-Cl）与8-羟基喹啉的络合产生了一个空气和水分稳定的配合物。采用对映体纯(+)-α-蒎烯，分离得到(+,+)-浸喹啉配合物[(+)-C10H17]2B(η2-N,O-C10H6NO)，并用光谱和晶体学方法对其进行了表征。从对映异构不纯的(+)-α-蒎烯制备Dip-Cl时，形成了杂手性(+,−)-Dip-Cl和同手性(+,+)-Dip-Cl和(−,−)-Dip-Cl的混合物，形成了立体异构体。我们建立了8-羟基喹啉络合方法，用手性高效液相色谱法对这些立体异构体进行定量。由于这是第一次对一种表现出不对称扩增的试剂进行定量分析，它使我们能够验证卡根对这种现象的部分模型，并评估用于测量立体异构体相对数量的β和K项。分析表明，杂手性(+,−)-Dip-Cl异构体倾向于形成；因此，立体异构体是…
We show that complexation of B-chlorodiisopinocampheylborane (Dip-Cl) with 8-hydroxyquinoline results in an air- and moisture-stable complex. Using enantiomerically pure (+)-α-pinene, the (+,+)-Dip-quinoline complex, [(+)-C10H17]2B(η2-N,O-C10H6NO), was isolated and characterized by spectroscopic and crystallographic methods. When Dip-Cl is prepared from enantiomerically impure (+)-α-pinene a mixture of heterochiral, (+,−)-Dip-Cl, and homochiral, (+,+)-Dip-Cl and (−,−)-Dip-Cl, stereoisomers are formed. We have developed the 8-hydroxyquinoline complexation method for quantification of these stereoisomers by chiral HPLC. Since this is the first quantitative analysis of a reagent that exhibits asymmetric amplification, it enables us to verify part of Kagan's model for this phenomenon and evaluate the terms β and K which are measures of the relative amounts of stereoisomers. Our analysis shows that there is a preference for the formation of the heterochiral (+,−)-Dip-Cl isomer; therefore, the stereoisomers are...