Conformational Analysis of a Model Synthetic Prodiginine
Conformational Analysis of a Model Synthetic Prodiginine
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DOI：
10.1021/jo301008c
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发表时间：
2012-08-03
影响因子：
3.6
通讯作者：
Quesada, Roberto
中科院分区：
文献类型：
--
作者：
Garcia-Valverde, Maria;Alfonso, Ignacio;Quesada, Roberto
对合成的模型前地吉宁进行了构象分析。在溶液中，该化合物表现出强烈的β构象偏好，其中所有的杂环相互顺式。当分子质子化时，这种构象提供了三个N-H基团与阴离子相互作用的理想排列。甲磺酸盐在d（6）-DMSO中也检测到不同的构象，归属于a构象，其中C环与OMe基团形成分子内氢键。在中性游离碱形式的该前衍生物的浓CDCl 3溶液中观察到同二聚体的形成。DFT计算和盐酸盐和甲磺酸盐的固态结构与在溶液中观察到的结果吻合得很好。不同的互变异构体，异构体和超分子复合物的相对能量的一个完整的研究支持在水和气相中的β构象的偏好。
A conformational analysis of a synthetic model prodiginine was carried out. In solution this compound showed a strong preference for the beta conformation, in which all the heterocycles are mutually cis. This conformation provided an ideal alignment of the three N-H groups for interacting with anions when the molecule is protonated. A different conformation was also detected in d(6)-DMSO for the mesylate salt, assigned to the a conformation, in which the C ring is engaged in an intramolecular hydrogen bond with the OMe group. The formation of a homodimer was observed in concentrated CDCl3 solutions of the neutral free base form of this prodiginine derivative. DFT calculations and the solid state structures of the hydrochloric and methanesulfonic acid salts were in good agreement with the results observed in solution. A complete study of the relative energies of different tautomers, isomers, and supramolecular complexes supported the preference for the beta conformation both in water and in the gas phase.