Article ID Journal Published Year Pages File Type
5419028 Journal of Molecular Structure: THEOCHEM 2006 6 Pages PDF
Abstract
Acid-promoted E/Z isomerization of oximes in water is studied by means of theoretical calculations at the B3LYP/6-31G(d,p) level. We have considered a simple derivative, acetaldoxime, as a model to discuss the isomerization mechanism in more complex systems. The solvent is represented by a continuum or by a discrete-continuum model. Our calculations suggest that E/Z isomerization in water occurs through the formation of a protonated oxime-water adduct that involves the creation of a C(oxime)-O(water) bond and lies 14.2 kcal/mol above the separated reactants. In this intermediate, there is a single CN bond and rotation around this bond is free. The previously proposed mechanism assumed water addition to the CN double bond of the oxime with formation of a tetrahedral intermediate To. We predict this mechanism to be significantly less favorable than the one proposed in the present work.
Related Topics
Physical Sciences and Engineering Chemistry Physical and Theoretical Chemistry
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