Three Hydrogen Bond Donor Catalysts: Oxyanion Hole Mimics and Transition State Analogues

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• 作者：Evgeny V. Beletskiy ; Jacob Schmidt ; Xue-Bin Wang ; Steven R. Kass
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：November 14, 2012
• 年：2012
• 卷：134
• 期：45
• 页码：18534-18537
• 全文大小：236K
• 年卷期：v.134,no.45(November 14, 2012)
• ISSN：1520-5126

文摘

Enzymes and their mimics use hydrogen bonds to catalyze chemical transformations. Small-molecule transition state analogues of oxyanion holes have been characterized by computations, gas-phase IR and photoelectron spectroscopy, and determination of their binding constants in acetonitrile. A new class of hydrogen bond catalysts is proposed (donors that can contribute three hydrogen bonds to a single functional group) and demonstrated in a Friedel鈥揅rafts reaction. The employed catalyst was observed to react 100 times faster than its rotamer that can employ only two hydrogen bonds. The former compound also binds anions more tightly and was found to have a thermodynamic advantage.