Chemistry: A European Journal 2011-07-11

Solvent and TMEDA effects on the configurational stability of chiral lithiated aryloxiranes.

Filippo Maria Perna, Antonio Salomone, Mariangela Dammacco, Saverio Florio, Vito Capriati

Index: Chemistry 17(29) , 8216-25, (2011)

Full Text: HTML

Abstract

The employment of hexane/N,N,N',N'-tetramethylethylenediamine (TMEDA) dramatically hinders the racemization of those lithiated styrene oxides (trifluoromethyl-, chloro-, and phenylthio-substituted) that have been proven to be configurationally unstable in THF on the timescale of their reactions. The barriers to inversion and the activation parameters, calculated (Eyring equation) for reactions performed in THF, THF/TMEDA, and hexane/TMEDA, suggest the intervention of particular enantiomerization mechanisms for each case. The role of TMEDA in both coordinating and noncoordinating solvents has also been questioned and discussed in light of the kinetic data gathered and a model for deprotonation in hexane/TMEDA has also been proposed. The synthetic benefits of our results became apparent on establishing an asymmetric synthesis of an industrially important antifungal agent.Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Related Compounds

  • TMEDA
  • (S)-Styrene oxide
  • (S)-Styrene oxide
  • Styrene oxide

Related Articles:

Aptamer-based polyvalent ligands for regulated cell attachment on the hydrogel surface.

2015-04-13

[Biomacromolecules 16(4) , 1382-9, (2015)]

Polymerization of affinity ligands on a surface for enhanced ligand display and cell binding.

2014-12-08

[Biomacromolecules 15(12) , 4561-9, (2014)]

Kafirin adsorption on ion-exchange resins: isotherm and kinetic studies.

2014-08-22

[J. Chromatogr. A. 1356 , 105-16, (2014)]

Use of an enzyme-assisted method to improve protein extraction from olive leaves.

2015-02-15

[Food Chem. 169 , 28-33, (2014)]

Effects of pentylenetetrazole kindling on mitogen-activated protein kinases levels in neocortex and hippocampus of mice.

2014-12-01

[Neurochem. Res. 39(12) , 2492-500, (2014)]

More Articles...