화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.130, No.51, 17334-17341, 2008
Structures of beta-Amino Ester Enolates: New Strategies Using the Method of Continuous Variation
The solution structures of four enolates derived from beta-amino esters are investigated using Li-6 NMR spectroscopy in conjunction with the method of continuous variation (method of Job). Ensembles of homo- and heteroaggregated enolates are generated by mixing enantiomers of a single enolate (R/S mixtures), opposite antipodes of two different enolates (R/S' mixtures), and the same antipodes of two different enolates (R/R' mixtures). The numbers of observable aggregates and their dependence on the mole fraction of the two enolates confirm the hexamer assignments. Inherent symmetries observable in the Li-6 NMR spectra show the stereochemistry of chelation about the hexagonal drum.