Synthesis of methyl-α-d-glucopyranoside-based azacrown ethers and their application in enantioselective reactions

Attila Makó, Áron Szöllosy, György Keglevich, Dóra K. Menyhárd, Péter Bakó, László Toke

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

New chiral monoaza-15-crown-5 compounds anellated to methyl-4,6-O-(1- naphthyl)methylene-α-d-glucopyranoside (2a-2b), to methyl-4,6-O- isopropylidene-α-d-glucopyranoside (3a-3b) and to methyl-α-d- glucopyranoside (4a-4b) have been synthesized. Several representatives of these crown ethers showed significant asymmetric induction as chiral phase transfer catalysts, among them 2a proved to be the most efficient one inducing 90% ee in the Michael addition of 2-nitropropane to chalcone, 48% ee in the Darzens condensation of phenacyl-chloride with benzaldehyde and 89% ee in the epoxidation of chalcone with tert-butyl hydroperoxide. The catalytic results were compared with those obtained earlier with macrocycles 1a-1b incorporating a 4,6-O- benzylidene protecting moiety. It occurred that the enantioselectivity is influenced to a great extent by the substituents on the C(4) and C(6) atoms of the monosaccharide. Lower enantioselectivities were obtained in the reactions of the chalcone analogues in the presence of catalyst 2a than in the case of the proper chalcone.

Original languageEnglish
Pages (from-to)525-535
Number of pages11
JournalMonatshefte fur Chemie
Volume139
Issue number5
DOIs
Publication statusPublished - May 2008

Fingerprint

Chalcone
Ethers
Enantioselectivity
Crown Ethers
tert-Butylhydroperoxide
Catalysts
Epoxidation
Monosaccharides
Chlorides
Condensation
Atoms

Keywords

  • Asymmetric catalysis
  • Crown ether
  • Michael addition
  • Phase-transfer catalysis

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

@article{3226f493c6b24924b9ea23ebaecaeb0c,
title = "Synthesis of methyl-α-d-glucopyranoside-based azacrown ethers and their application in enantioselective reactions",
abstract = "New chiral monoaza-15-crown-5 compounds anellated to methyl-4,6-O-(1- naphthyl)methylene-α-d-glucopyranoside (2a-2b), to methyl-4,6-O- isopropylidene-α-d-glucopyranoside (3a-3b) and to methyl-α-d- glucopyranoside (4a-4b) have been synthesized. Several representatives of these crown ethers showed significant asymmetric induction as chiral phase transfer catalysts, among them 2a proved to be the most efficient one inducing 90{\%} ee in the Michael addition of 2-nitropropane to chalcone, 48{\%} ee in the Darzens condensation of phenacyl-chloride with benzaldehyde and 89{\%} ee in the epoxidation of chalcone with tert-butyl hydroperoxide. The catalytic results were compared with those obtained earlier with macrocycles 1a-1b incorporating a 4,6-O- benzylidene protecting moiety. It occurred that the enantioselectivity is influenced to a great extent by the substituents on the C(4) and C(6) atoms of the monosaccharide. Lower enantioselectivities were obtained in the reactions of the chalcone analogues in the presence of catalyst 2a than in the case of the proper chalcone.",
keywords = "Asymmetric catalysis, Crown ether, Michael addition, Phase-transfer catalysis",
author = "Attila Mak{\'o} and {\'A}ron Sz{\"o}llosy and Gy{\"o}rgy Keglevich and Menyh{\'a}rd, {D{\'o}ra K.} and P{\'e}ter Bak{\'o} and L{\'a}szl{\'o} Toke",
year = "2008",
month = "5",
doi = "10.1007/s00706-007-0799-7",
language = "English",
volume = "139",
pages = "525--535",
journal = "Monatshefte fur Chemie",
issn = "0026-9247",
publisher = "Springer Wien",
number = "5",

}

TY - JOUR

T1 - Synthesis of methyl-α-d-glucopyranoside-based azacrown ethers and their application in enantioselective reactions

AU - Makó, Attila

AU - Szöllosy, Áron

AU - Keglevich, György

AU - Menyhárd, Dóra K.

AU - Bakó, Péter

AU - Toke, László

PY - 2008/5

Y1 - 2008/5

N2 - New chiral monoaza-15-crown-5 compounds anellated to methyl-4,6-O-(1- naphthyl)methylene-α-d-glucopyranoside (2a-2b), to methyl-4,6-O- isopropylidene-α-d-glucopyranoside (3a-3b) and to methyl-α-d- glucopyranoside (4a-4b) have been synthesized. Several representatives of these crown ethers showed significant asymmetric induction as chiral phase transfer catalysts, among them 2a proved to be the most efficient one inducing 90% ee in the Michael addition of 2-nitropropane to chalcone, 48% ee in the Darzens condensation of phenacyl-chloride with benzaldehyde and 89% ee in the epoxidation of chalcone with tert-butyl hydroperoxide. The catalytic results were compared with those obtained earlier with macrocycles 1a-1b incorporating a 4,6-O- benzylidene protecting moiety. It occurred that the enantioselectivity is influenced to a great extent by the substituents on the C(4) and C(6) atoms of the monosaccharide. Lower enantioselectivities were obtained in the reactions of the chalcone analogues in the presence of catalyst 2a than in the case of the proper chalcone.

AB - New chiral monoaza-15-crown-5 compounds anellated to methyl-4,6-O-(1- naphthyl)methylene-α-d-glucopyranoside (2a-2b), to methyl-4,6-O- isopropylidene-α-d-glucopyranoside (3a-3b) and to methyl-α-d- glucopyranoside (4a-4b) have been synthesized. Several representatives of these crown ethers showed significant asymmetric induction as chiral phase transfer catalysts, among them 2a proved to be the most efficient one inducing 90% ee in the Michael addition of 2-nitropropane to chalcone, 48% ee in the Darzens condensation of phenacyl-chloride with benzaldehyde and 89% ee in the epoxidation of chalcone with tert-butyl hydroperoxide. The catalytic results were compared with those obtained earlier with macrocycles 1a-1b incorporating a 4,6-O- benzylidene protecting moiety. It occurred that the enantioselectivity is influenced to a great extent by the substituents on the C(4) and C(6) atoms of the monosaccharide. Lower enantioselectivities were obtained in the reactions of the chalcone analogues in the presence of catalyst 2a than in the case of the proper chalcone.

KW - Asymmetric catalysis

KW - Crown ether

KW - Michael addition

KW - Phase-transfer catalysis

UR - http://www.scopus.com/inward/record.url?scp=42749087459&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=42749087459&partnerID=8YFLogxK

U2 - 10.1007/s00706-007-0799-7

DO - 10.1007/s00706-007-0799-7

M3 - Article

AN - SCOPUS:42749087459

VL - 139

SP - 525

EP - 535

JO - Monatshefte fur Chemie

JF - Monatshefte fur Chemie

SN - 0026-9247

IS - 5

ER -