593284-20-9Relevant academic research and scientific papers
Fine-tuning the structures of chiral diamine ligands in the catalytic asymmetric aldol reactions of trifluoromethyl aromatic ketones with linear aliphatic ketones
Zong, Hua,Huang, Huayin,Bian, Guangling,Song, Ling
, p. 11768 - 11773 (2014)
In this work, we thoroughly investigated the effect of structural differentiation of a series of N,N-disubstituted chiral diamine ligands on the catalytic asymmetric aldol reactions between trifluoromethyl ketones and linear aliphatic ketones for the cons
The use of benzamide derivatives of secondary amines for stereochemical studies by circular dichroism
Gawronski, Jacek,Kolbon, Halina,Kwit, Marcin
, p. 85 - 92 (2007/10/03)
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 U.D. Chisholm, J. Golik, B. Krishnan, J.A. Matson, D.L. Van Vranken, J. Am. Chem. Soc. 1999, 121: 3801-3802) claimed a caveat in the application of the exciton chirality method to benzamides derived from secondary amines. By the use of benzoyl derivatives of amino alcohols (1-4) and diamines (5, 6) of known absolute configuration we demonstrate that the 250-210 nm range exciton Cotton effects due to secondary and tertiary benzamides are generally of opposite sign. The origin of such disparity is traced to different conformational equilibria of the amide C-N bond in secondary and tertiary benzamides, as shown by semiempirical molecular modelling and NMR data. This feature can be useful in the determination of absolute configuration by analysis of the CD spectra due to exciton coupling of tertiary benzamides.
