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A Lewis Acidity Scale in Relation to Rate Constants of Lewis Acid Catalyzed Organic Reactions
Author(s) -
Hilt Gerhard,
Pünner Florian,
Möbus Juri,
Naseri Vesal,
Bohn Martin A.
Publication year - 2011
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201101029
Subject(s) - chemistry , lewis acids and bases , catalysis , reaction rate constant , chemical shift , lewis acid catalysis , nuclear magnetic resonance spectroscopy , zinc , organic chemistry , inorganic chemistry , kinetics , quantum mechanics , physics
The quantification of Lewis acidity is accomplished by a deuterated quinolizidine probe utilizing 2 H NMR spectroscopy. The chemical shifts of the 2 H 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 2 H 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.