Di-(R,R)-1-[10-(1-hydroxy-2,2,2-trifluoroethyl)-9-anthryl]-2,2,2-trifluoroethyl Muconate:  A Highly Chiral Cavity for Enantiodiscrimination by NMR

Abstract

A new chiral molecular tweezer, di-(R,R)-1-[10-(1-hydroxy-2,2,2-trifluoroethyl)-9-anthryl]-2,2,2-trifluoroethyl muconate 2, was synthesized in enantiopure form, and its geometry was studied using NMR and molecular mechanics. The effectiveness of 2 as a chiral solvating agent for determining the enantiomeric composition of chiral compounds using NMR was demonstrated, improving the results obtained with other methods. The stoichiometry and the association constant of the resulting diastereomeric complexes were studied, and their geometry was analyzed by NOE and 1H NMR.

Evidence of Enantiomers of Spiroglycol. Distinction by Using α,α′-Bis(trifluoromethyl)-9,10-anthracenedimethanol as a Chiral Solvating Agent and by Derivatization with Chiral Acids

“…The corresponding enantiomeric composition can be easily determined by the direct integration of the split signals if there is enough chemical shift difference. Pure shift NMR spectroscopy and/or 13 C­{ 1 H}-NMR experiments could be some good strategies to overcome the overcrowded spectrum troubles.…”

A New Chirally Organized Trifluoromethylanthrylmethanol Derivative and Its Application as Chiral Solvating Agent

“…[13] Herein, we report on the synthesis and the enantiodifferentiation behaviour of 1,1'-(((10,10'-(1,1'-binaphthalene)-2,2'-diylbis(oxy))bis(methylene))bis (anthracene-10,9-diyl))bis(2,2,2-trifluoroethanol), 4, a new CSA which incorporates both, axial and central chirality, and additionally presents a remarkable increase of its aromatic surface. This new compound contains two anthracene subunits [14][15][16][17] and a (1,1'-binaphtalene)-2,2'-diol (BINOL) moiety, which has also been used previously as a CSA itself. [18][19][20]…”

Molecular tweezers for enantiodiscrimination in NMR: Di‐(R,R)‐1‐[10‐(1‐hydroxy‐2,2,2‐trifluoroethyl)‐9‐anthryl]‐2,2,2‐trifluoroethyl benzenedicarboxylates

“…[12][13][14][15][16] Recently, we have developed a chiral molecular tweezers which could be used as a chiral solvating agent and shows a high performance with several enantiomeric mixtures. 17 The muconate of di-a,a 0 -(bistrifluoromethyl)-9,10-anthracenedimethanol (ABTE) 18 1 features two anthracene rings separated by a spacer which defines a chiral cavity. The geometry, volume, and general characteristics of this cavity depend on the nature of spacer (the dicarboxylic acid), the relative position of the ABTE groups, their dimensions and the presence and/or position of the two hydroxyl functions, which allow the formation of internal hydrogen bonds.…”