J 2002

Enantiodiscrimination in NMR spectra and X-ray structures of diastereomeric salts of trans-4-(4-fluorophenyl)-3-hydroxymethyl-1-methylpiperidine with (S)-Mosher acid

NAVRÁTILOVÁ, Hana, René DE GELDER and Zdeněk KŘÍŽ

Basic information

Original name

Enantiodiscrimination in NMR spectra and X-ray structures of diastereomeric salts of trans-4-(4-fluorophenyl)-3-hydroxymethyl-1-methylpiperidine with (S)-Mosher acid

Authors

NAVRÁTILOVÁ, Hana (203 Czech Republic, guarantor), René DE GELDER (528 Netherlands) and Zdeněk KŘÍŽ (203 Czech Republic)

Edition

J. Chem. Soc. Perkin Trans. 2, Cambridge, U.K. Royal Society of Chemistry, 2002, 1472-779X

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10401 Organic chemistry

Country of publisher

Czech Republic

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 1.911

RIV identification code

RIV/00216224:14310/02:00007020

Organization unit

Faculty of Science

UT WoS

000179653700021

Keywords in English

enantiodiscrimination; (S)-Mosher acid; NMR; diastereomeric salts;free energy;
Změněno: 14/5/2003 14:38, RNDr. Hana Navrátilová, Ph.D.

Abstract

V originále

Signal anisochrony delta in NMR spectra of racemic trans-4-(4-fluorophenyl)-3-hydroxymethyl-1-methylpiperidine 1 induced on the formation of diastereomeric salt complexes with (S)-Mosher acid 2 showed a strong dependence on solvent polarity, concentration, stoichiometric ratio and enantiomeric composition. X-ray structures of the salts, 3a and 3b, revealed that the conformations of the protonated base in ion pairs are very similar with respect to interatomic distances, bond and torsion angles but the mutual orientation of counterions in ion pairs differs significantly. It is suggested that the conformations of transient diastereomeric complexes in solution, responsible for delta;, resemble those in solid state. Furthermore, ab initio calculations performed on the optimized X-ray geometries of both ion pairs showed that the free energy of 3a is lower than that of 3b. This implies that the association constant for the formation of 3a is higher than that of 3b.

Links

MSM 143100011, plan (intention)
Name: Struktura a vazebné poměry, vlastnosti a analýza syntetických a přírodních molekulových ansamblů
Investor: Ministry of Education, Youth and Sports of the CR, Structure and character of bonding, properties and analysis of synthetic and natural molecular ensembles