Pseudo-cyclic structures of mono- and di-azaderivatives of malondialdehydes. Synthesis and conformational disentanglement by computational analyses
作者:María P. Romero-Fernández、Martín Ávalos、Reyes Babiano、Pedro Cintas、José L. Jiménez、Mark E. Light、Juan C. Palacios
DOI:10.1039/c4ob01507j
日期:——
were performed for all possible neutral tautomers and conformers in the gas phase and compared to those in polar solvents (CHCl3, DMSO, and EtOH) at the M06-2X/6-311++G(d,p) level. Tautomeric equilibria and conformational preferences can be rationalized in terms of structural factors, which can be roughly estimated as summation or subtractions of intramolecular interactions. As expected, a key role is
丙二醛的单-和二氮杂衍生物,即3-烷基(芳基)氨基-2-芳基丙烯醛和1,5-二烷基(芳基)-3-芳基乙烯基am是开链系统,其中可以设想扩展的电子离域和假芳香性。合成了一组功能多样的化合物,并通过光谱数据和X射线衍射法对其进行了表征。对气相中所有可能的中性互变异构体和构象异构体进行了量子化学计算,并与极性溶剂(CHCl 3,DMSO和EtOH)作为M06-2X / 6-311 ++ G(d,p)级别。互变异构平衡和构象偏好可以根据结构因素进行合理化,可以粗略地估计为分子内相互作用的总和或减去。不出所料,分子内氢键起着关键作用,氢键的强度从气相到极性乙醇不等。该问题还涉及共振辅助氢键的概念,其中供体和受体原子通过π共轭体系连接。从HOMA指数和其他离域参数推断,最稳定的构象异构体(结构a和c)具有高度的假芳香性。