The Use of Benzamide Derivatives of Secondary Amines for Stereochemical Studies by Circular Dichroism
作者:Jacek Gawroński、Halina Kołbon、Marcin Kwit
DOI:10.1080/10242430212196
日期:2002.3
The benzamide chromophore is widely used as a Cottonogenic derivative of primary amines for stereochemical studies by circular dichroism. The assignments based on the exciton chirality method are reliable since the benzamide group has well-defined geometry and conformation. A recent report (J.D. Chisholm, J. Golik, B. Krishnan, J.A. Matson, D.L. Van Vranken, J. Am. Chem. Soc. 1999, 121: 3801-3802)
苯甲酰胺发色团广泛用作伯胺的产棉衍生物,用于通过圆二色性进行立体化学研究。由于苯甲酰胺基团具有明确定义的几何构型,因此基于激子手性方法的分配是可靠的。最近的一份报告(JD Chisholm,J。Golik,B。Krishnan,JA Matson,DL Van Vranken,J。Am。Chem。Soc。1999,121:3801-3802)要求将激子手性方法应用于衍生自仲胺的苯甲酰胺。通过使用已知绝对构型的氨基醇(1-4)和二胺(5、6)的苯甲酰基衍生物,我们证明了由于仲和叔苯甲酰胺引起的250-210 nm范围激子棉花效应通常相反。如半经验分子模型和NMR数据所示,这种差异的根源可追溯到仲,叔苯甲酰胺中酰胺CN键的不同构象平衡。由于叔苯甲酰胺的激子偶合,该特征可用于通过分析CD光谱确定绝对构型。