Conformational studies by dynamic NMR. 100. Enantiomerization process of stereolabile atropisomers in pyridine-substituted adamantane derivatives

Daniele Casarini; Carmine Coluccini; Lodovico Lunazzi; Andrea Mazzanti; Romina Rompietti

doi:10.1021/jo0493471

Conformational studies by dynamic NMR. 100. Enantiomerization process of stereolabile atropisomers in pyridine-substituted adamantane derivatives

J Org Chem. 2004 Aug 20;69(17):5746-8. doi: 10.1021/jo0493471.

Authors

Daniele Casarini¹, Carmine Coluccini, Lodovico Lunazzi, Andrea Mazzanti, Romina Rompietti

Affiliation

¹ Chemistry Department, University of Basilicata, Potenza, Italy.

PMID: 15307749
DOI: 10.1021/jo0493471

Abstract

The barriers for interconverting the conformational enantiomers (stereolabile atropisomers) of pyridine-substituted adamantane derivatives have been determined by dynamic 13C NMR spectroscopy. The trend of these values parallels that anticipated by MM calculations. In at least one case, the computed structure was found to agree with that obtained by single-crystal X-ray diffraction. In addition, it has been possible to achieve a physical separation of a pair of these stereolabile atropisomers at -60 degrees C by means of the enantioselective cryogenic HPLC technique.