Enantioselective separation of enantiomeric amides on three amylose-based chiral stationary phases: Effects of backbone and carbamate side chain chiralities

Separation of Chiral Compounds on Polysaccharide Columns

“…In a series of papers, Booth et al developed a series of relationships with the goal of being able to predict the enantioselective behavior of many types of compounds on amylosic chiral stationary phases [71][72][73]. A goal of these studies was to develop a quantitiative structure-enantioselective retention relationship (QSERR) which takes into account hydrogen bonding and aromaticity of the solutes [71].…”

“…In the ensuing years, many studies were performed to understand how the coated polysaccharide esters and carbamates actually worked [60][61][62][63][64][65][66][67][68][69][70][71][72][73]. Most of the these studies were concerned with the effects of substituents on the benzoate ester or phenylcarbamate rings, the effect of size and shape of various alcohol mobile-phase modifiers, and the systematic variation of solute structure to determine the effects that various structural elements had on the type of interactions between chiral stationary phase and solvent.…”

“…The authors then postulate that the mechanism process is "conformationally driven" rather than proceeding through the traditional "three-point" interaction model [71]. Later these studies were expanded to examine the retention of 17 amide compounds on ADMPC, ASMBC, and ARMBC, in which ARMBC is the amylose tris[(R)-α-methylbenzylcarbamate] [72]. It was concluded that this chirality of the side chain has almost no effect on the chiral selectivity of the CSP.…”

“…Once again, structure-retention relationships were developed to describe the results. For all compounds, the elution order was determined by the chirality of the amylosic backbone, while the magnitude of the enantiomeric separations was affected by the chirality of the carbamate side chain [72].…”

Direct reductive coupling of indoles to nitrostyrenes en route to (indol-3-yl)acetamides

“…16 Colorless crystals, mp 109-110 C; physical and spectral properties of this compound were identical to those of commercially available authentic sample. 0, 143.7, 142.9, 139.4, 132.6, 128.9 (2C), 128.8 (2C), 127.3, 121.9, 117.8, 117.6, 64.4 (2C), 58.1; FT-IR (NaCl, cm À1 ): 3428,3193,1659,1590,1497,1284,1256,1070; HRMS (TOF-ES): calcd for C 16 H 15 NNaO 3 (M + Na) + : 392.0944, found 392.0942 (0.5 ppm).…”