Theoretical study of the asymmetric phase-transfer mediated epoxidation of chalcone catalyzed by chiral crown ethers derived from monosaccharides

Attila Makó, Dóra K. Menyhárd, P. Bakó, G. Keglevich, L. Tőke

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

The synthesis of a novel, optically active crown ether derived from α-d-altropyranoside is described. A significantly different asymmetric induction was generated by the α-d-glucopyranoside-, α-d-mannopyranoside- and α-d-altropyranoside-based chiral crown catalysts in the epoxidation of trans-chalcone with tert-butyl hydroperoxide under phase-transfer catalytic conditions. It was shown that absolute configuration of the crown-ring fused carbon atoms of the monosaccharides has a great impact on the enantioselectivity. The asymmetric induction could be well explained by considering the possible mechanistic pathway. Molecular modeling (MCMM) and subsequent DFT calculations - in accordance with the experimental results - indicate that the use of glucopyranoside-based catalyst 1 and that of mannopyranoside-based crown ether 2 results in the preferred formation of the opposite antipodes (2R,3S and 2S,3R, respectively) of the corresponding epoxyketone. At the same time, practically no asymmetric induction was proved if altropyranoside-based crown 3 is applied as the catalyst. The computational results are in qualitative agreement with the experimental data.

Original languageEnglish
Pages (from-to)336-342
Number of pages7
JournalJournal of Molecular Structure
Volume892
Issue number1-3
DOIs
Publication statusPublished - Dec 15 2008

Fingerprint

Crown Ethers
Chalcone
Epoxidation
Monosaccharides
Mannose
Catalysts
tert-Butylhydroperoxide
Molecular modeling
Enantioselectivity
Discrete Fourier transforms
Carbon
Atoms

Keywords

  • Asymmetric epoxidation
  • Chiral crown ether
  • Enantioselective synthesis
  • Theoretical calculations

ASJC Scopus subject areas

  • Spectroscopy
  • Analytical Chemistry
  • Inorganic Chemistry
  • Organic Chemistry

Cite this

@article{455bd1e997774ce792c694488e660c0d,
title = "Theoretical study of the asymmetric phase-transfer mediated epoxidation of chalcone catalyzed by chiral crown ethers derived from monosaccharides",
abstract = "The synthesis of a novel, optically active crown ether derived from α-d-altropyranoside is described. A significantly different asymmetric induction was generated by the α-d-glucopyranoside-, α-d-mannopyranoside- and α-d-altropyranoside-based chiral crown catalysts in the epoxidation of trans-chalcone with tert-butyl hydroperoxide under phase-transfer catalytic conditions. It was shown that absolute configuration of the crown-ring fused carbon atoms of the monosaccharides has a great impact on the enantioselectivity. The asymmetric induction could be well explained by considering the possible mechanistic pathway. Molecular modeling (MCMM) and subsequent DFT calculations - in accordance with the experimental results - indicate that the use of glucopyranoside-based catalyst 1 and that of mannopyranoside-based crown ether 2 results in the preferred formation of the opposite antipodes (2R,3S and 2S,3R, respectively) of the corresponding epoxyketone. At the same time, practically no asymmetric induction was proved if altropyranoside-based crown 3 is applied as the catalyst. The computational results are in qualitative agreement with the experimental data.",
keywords = "Asymmetric epoxidation, Chiral crown ether, Enantioselective synthesis, Theoretical calculations",
author = "Attila Mak{\'o} and Menyh{\'a}rd, {D{\'o}ra K.} and P. Bak{\'o} and G. Keglevich and L. Tőke",
year = "2008",
month = "12",
day = "15",
doi = "10.1016/j.molstruc.2008.05.057",
language = "English",
volume = "892",
pages = "336--342",
journal = "Journal of Molecular Structure",
issn = "0022-2860",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - Theoretical study of the asymmetric phase-transfer mediated epoxidation of chalcone catalyzed by chiral crown ethers derived from monosaccharides

AU - Makó, Attila

AU - Menyhárd, Dóra K.

AU - Bakó, P.

AU - Keglevich, G.

AU - Tőke, L.

PY - 2008/12/15

Y1 - 2008/12/15

N2 - The synthesis of a novel, optically active crown ether derived from α-d-altropyranoside is described. A significantly different asymmetric induction was generated by the α-d-glucopyranoside-, α-d-mannopyranoside- and α-d-altropyranoside-based chiral crown catalysts in the epoxidation of trans-chalcone with tert-butyl hydroperoxide under phase-transfer catalytic conditions. It was shown that absolute configuration of the crown-ring fused carbon atoms of the monosaccharides has a great impact on the enantioselectivity. The asymmetric induction could be well explained by considering the possible mechanistic pathway. Molecular modeling (MCMM) and subsequent DFT calculations - in accordance with the experimental results - indicate that the use of glucopyranoside-based catalyst 1 and that of mannopyranoside-based crown ether 2 results in the preferred formation of the opposite antipodes (2R,3S and 2S,3R, respectively) of the corresponding epoxyketone. At the same time, practically no asymmetric induction was proved if altropyranoside-based crown 3 is applied as the catalyst. The computational results are in qualitative agreement with the experimental data.

AB - The synthesis of a novel, optically active crown ether derived from α-d-altropyranoside is described. A significantly different asymmetric induction was generated by the α-d-glucopyranoside-, α-d-mannopyranoside- and α-d-altropyranoside-based chiral crown catalysts in the epoxidation of trans-chalcone with tert-butyl hydroperoxide under phase-transfer catalytic conditions. It was shown that absolute configuration of the crown-ring fused carbon atoms of the monosaccharides has a great impact on the enantioselectivity. The asymmetric induction could be well explained by considering the possible mechanistic pathway. Molecular modeling (MCMM) and subsequent DFT calculations - in accordance with the experimental results - indicate that the use of glucopyranoside-based catalyst 1 and that of mannopyranoside-based crown ether 2 results in the preferred formation of the opposite antipodes (2R,3S and 2S,3R, respectively) of the corresponding epoxyketone. At the same time, practically no asymmetric induction was proved if altropyranoside-based crown 3 is applied as the catalyst. The computational results are in qualitative agreement with the experimental data.

KW - Asymmetric epoxidation

KW - Chiral crown ether

KW - Enantioselective synthesis

KW - Theoretical calculations

UR - http://www.scopus.com/inward/record.url?scp=55749085636&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=55749085636&partnerID=8YFLogxK

U2 - 10.1016/j.molstruc.2008.05.057

DO - 10.1016/j.molstruc.2008.05.057

M3 - Article

AN - SCOPUS:55749085636

VL - 892

SP - 336

EP - 342

JO - Journal of Molecular Structure

JF - Journal of Molecular Structure

SN - 0022-2860

IS - 1-3

ER -