New chiral fluoroanthryl derivatives: Resolution of the enantiomers by chromatography on cellulose esters and their evaluation as chiral solvating agents in NMR spectroscopy

Abstract

Abstract2,2,2‐Trifluoro‐1‐(9‐anthryl)ethanol (TFAE) has now been widely used as a powerful chiral solvating agent for NMR spectroscopy. In connection with the development of a new general synthesis of halogenoalkylalkanols, starting from the corresponding ketone or aldehyde, we synthesized some halogenoalkyl‐1‐(9‐anthryl)methanol derivatives liable to work as chiral solvating agents. The racemic anthryl derivatives were preparatively resolved into their corresponding enantiomers by chromatography on triacetyl cellulose (CTA I) or on meta‐methylbenzoyl cellulose beads as chiral stationary phases. Their effectiveness as chiral solvating agents was measured as the magnitude of the splitting induced in the 1H‐NMR spectra of 1‐phenylethylamine and of (1‐phenylethyl)methyl ether in comparison with splitting caused by TFAE. While TFAE induced the largest splitting for 1‐phenylethylamine, 2,2,3,3,3‐pentafluoro‐1‐(9‐anthryl)propanol 2 was more effective in the case of (1‐phenylethyl)methyl ether, pointing out that depending on the substrate, other derivatives of the TFAE type can be very useful as chiral solvating agents.