Circular dichroism spectroscopy of 2‐aminotetralins

Abstract

The circular dichroism (CD) spectra of a series of oxygenated 2-(dipropylamino)tetralin derivatives are reported. On the basis of known absolute configurations and conformational preferences of the compounds, the validity of published correlations between the sign of the ' Lb Cotton effect and the three-dimensional structure was examined. Contrary to predictions, substitution in position 6 or 7 of the tetralin moiety did not change the sign of the ' L,, Cotton effect. An unexpected sign inversion was, however, observed in some of the compounds containing methyl substituents in the nonaromatic ring. The Occurrence of this inversion was not correlated with a change in conformational behaviour and varied depending on the position and nature of the aromatic substituent. No correlations were obvious between the sign of the ' Lb Cotton effect and the absolute configuration and conformatiod preferences of the compounds. Therefore, at present, CD spectroscopy does not appear to be useful in assignments of the absolute configurations of 2-(dipropylamino)tetralin derivatives.0 1995 Wiley-Liss. Inc.

Vibrational and electronic circular dichroism spectroscopies and DFT calculations for the assignment of the absolute configuration of hydroxy-substituted 2-tetralols

“…11 However, failures of the rules have been encountered in some instances. 12 A powerful non-empirical method to determine the AC of molecules in solution has emerged in recent years, i.e. measuring vibrational circular dichroism (VCD) 13 and/or electronic circular dichroism (ECD) and comparing the experimental spectra with those predicted by density functional theory (DFT) and timedependent DFT (TDDFT) calculations.…”