A Lewis Acidity Scale in Relation to Rate Constants of Lewis Acid Catalyzed Organic Reactions
A Lewis Acidity Scale in Relation to Rate Constants of Lewis Acid Catalyzed Organic Reactions
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DOI：
10.1002/ejoc.201101029
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发表时间：
2011-10-01
影响因子：
2.8
通讯作者：
Bohn, Martin A.
中科院分区：
文献类型：
--
作者：
Hilt, Gerhard;Puenner, Florian;Bohn, Martin A.
刘易斯酸度的定量是通过氘代喹里嗪探针利用H-2 NMR光谱完成的。报道了铝、硼、钛和锌卤化物的H-2NMR信号的化学位移。在准一级反应条件下，利用紫外/维斯光谱法测定了刘易斯酸催化的Diels-Alder反应和Povarov反应的速率常数。的H-2 NMR化学位移的幅度与许多刘易斯酸在同一顺序调查的有机转化的速率常数相关，而一些偏差被确定。
The quantification of Lewis acidity is accomplished by a deuterated quinolizidine probe utilizing H-2 NMR spectroscopy. The chemical shifts of the H-2 NMR signals for aluminum, boron, titanium, and zinc halides are reported. The rate constants for Lewis acid catalyzed reactions were determined by utilizing UV/Vis spectroscopy for Diels-Alder and Povarov reactions under pseudo-first-order conditions. The magnitude of the H-2 NMR chemical shifts correlates with the rate constants of the organic transformations for many Lewis acids investigated in the same order, whereas some deviations are identified.