期刊
CHEMISTRY-A EUROPEAN JOURNAL
卷 17, 期 42, 页码 11919-11929出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/chem.201101274
关键词
ab initio calculations; acid catalysis; computer chemistry; hydration; hydrolysis; twisted amides
资金
- National Science Foundation of China [20733002, 20873105]
- Ministry of Science and Technology [2011CB808504]
The acid-catalyzed reactions of twisted amides in water solution were investigated by using cluster-continuum model calculations. In contrast to the previous widely suggested concerted hydration of the C=O group, our calculations show that the reaction proceeds in a practically stepwise manner, and that the hydration and hydrolysis channels of the C-N bond compete. The Eigen ion (H3O+) is the key species involved in the reaction, and it modulates the hydration and hydrolysis reaction pathways. The phenyl substitution in the twisted amide not only activates the N-CO bond, but also stabilizes the hydrolysis product through n(N)->pi(phenyl) delocalization, leading exclusively to the hydrolysis product of the ring-opened carboxylic acid. Generally, the twisted amides are more active than the planar amides, and such a rate acceleration results mainly from the increase in exothermicity in the first N-protonation step; the second step of the nucleophilic attack is less affected by the twisting of the amide bond. The present results show good agreement with the available experimental observations.
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