Yeguas Violeta, Díaz Natalia, Campomanes Pablo, López Ramón
Departamento de Química Física y Analítica, Universidad de Oviedo, C/Julián Clavería, 8, 33006, Oviedo, Spain.
Dalton Trans. 2008 Dec 7(45):6427-34. doi: 10.1039/b810868d. Epub 2008 Oct 8.
Computations on the reaction of azetidin-2-one, N-sulfonate azetidin-2-one, and 3-formylamine-N-sulfonate azetidin-2-one with [Mo(OH)(eta3-C3H5)(CO)2(N2C2H4)] were performed at the B3LYP/6-31+G(d,p) (LANL2DZ for Mo augmented by f polarization functions with exponents 1.043) taking into account solvent effects by means of the PCM-UAHF model. According to our calculations, the rate-determining energy barrier for the azetidin-2-one case, 38.0 kcal mol(-1), becomes 28.8 and 26.1 kcal mol(-1) for the N-sulfonate azetidin-2-one and 3-formylamine-N-sulfonate azetidin-2-one ones, respectively. The presence of the sulfonate group is crucial to cleave the beta-lactam N1-C2 bond by the Mo complex thanks to the interaction of the sulfonate group with the hydroxyl and bidentate ligands of the complex. This could be of interest for the synthesis of beta-amino acids and their derivatives from beta-lactams in mild conditions and low polarity solvents promoted by organometallic complexes.
采用B3LYP/6 - 31 + G(d,p)（Mo采用LANL2DZ并通过指数为1.043的f极化函数增强）方法，借助PCM - UAHF模型考虑溶剂效应，对氮杂环丁烷 - 2 - 酮、N - 磺酸盐氮杂环丁烷 - 2 - 酮和3 - 甲酰胺 - N - 磺酸盐氮杂环丁烷 - 2 - 酮与[Mo(OH)(η3 - C3H5)(CO)2(N2C2H4)]的反应进行了计算。根据我们的计算，氮杂环丁烷 - 2 - 酮情况的速率决定能垒为38.0 kcal mol⁻¹，对于N - 磺酸盐氮杂环丁烷 - 2 - 酮和3 - 甲酰胺 - N - 磺酸盐氮杂环丁烷 - 2 - 酮，该能垒分别变为28.8 kcal mol⁻¹和26.1 kcal mol⁻¹。由于磺酸盐基团与配合物的羟基和双齿配体相互作用，磺酸盐基团的存在对于通过钼配合物裂解β - 内酰胺的N1 - C2键至关重要。这对于在有机金属配合物促进的温和条件和低极性溶剂中由β - 内酰胺合成β - 氨基酸及其衍生物可能具有重要意义。
