16888-96-3Relevant academic research and scientific papers
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.
Enantioselective Synthesis of Optically Pure Amino Alcohol Derivatives by Yeast Reduction
Fujisawa, Tamotsu,Hayashi, Hiroki,Kishioka, Yoshino
, p. 129 - 132 (2007/10/02)
Baker's yeast reduction of nitro- and imide-containing ketones gives the corresponding secondary alcohols in good yields with excellent optical purity.Among the imide groups examined, the ketones with saccharin moiety give the products in the best chemical and optical yields.
