Russian Journal of Bioorganic Chemistry, Vol. 31, No. 3, 2005, pp. 300–301. Translated from Bioorganicheskaya Khimiya, Vol. 31, No. 3, 2005, pp. 335–336.
Original Russian Text Copyright © 2005 by Kur’yanov, Priskoka, Chupakhina, Chirva.
LETTERS
TO THE EDITOR
A Phase-Transfer Glucosamination of Phenols Catalyzed
by Polyethylene Glycol
1
V. O. Kur’yanov, U. S. Priskoka, T. A. Chupakhina, and V. Ya. Chirva
Tauric National University, pr. Vernadskogo 4, Simferopol, 95007 Ukraine
Received November 12, 2004; in final form, January 11, 2005
Abstract—Glycosylation of phenols with α-D-glucosaminyl chloride peracetate catalyzed by polyethylene
glycol (PEG) was carried out in a solid–liquid phase transfer system at room temperature. The results were
compared with those previously obtained for the catalysis with various crown ethers. The catalytic activity of
PEG in this reaction was found to be comparable with those of 15-crown-5 and aromatic crown ethers.
Key words: aryl glycosides, crown ethers, glycosylation, poly(ethylene glycol)
1
It is known that, along with crown ethers, linear
polyethers, oligo- and polyethylene glycols, are known
to be phase-transfer catalysts for a variety of organic
reactions, in particular, for nucleophylic substitution
The General Glycosylation Procedure
A mixture of (I) (500 mg, 1.37 mmol) [6], or of
anhydrous finely powdered potassium carbonate
2
(
189 mg, 1.37 mmol or 851 mg, 6.17 mmol), the corre-
and oxidation [1]. We have previously demonstrated a
sponding phenol (1.378 mmol), and the corresponding
amount of PEG (Fluka) (see table) was stirred in 15 ml
of anhydrous acetonitrile at 20 ± 0.5°ë until the com-
plete conversion of substrate (according to TLC on
Sorbfil-AFV-UF, Sorbpolimer, Russia). The solid phase
was separated by filtration, the filtrate was evaporated
at a reduced pressure, and glycosides (V)–(VII) were
isolated by crystallization from isopropanol.
high efficiency of various CEs for the use in the inter-
phase catalytic processes of glycosylation of aromatic
compounds in the solid phase–liquid phase system [2–
5
]. A closeness of the chemical nature of oligoethylene
glycols and CEs allows one to expect their catalytic
activity would be comparable with that of macrocyclic
polyethers.
The special features of the reaction of β-glycosyla-
tion of phenol (II), 4-methoxyphenol (III), and 4-nitro-
Phenyl 2-acetamido-2-deoxy-3,4,6-tri-O-acetyl-
phenol (IV) with α-D-glucosaminyl chloride peracetate b-D-glucopyranoside (V); mp 204–206°C; [α]
5
46
(
I) in the solid phase–liquid phase system using PEG −14° (c 1.0, chloroform) (lit. [7]: yield 73%; mp 203–
(
M 4000) as a phase transfer catalyst (see Scheme 1) 204°C; [α] –14.5° (c 0.9, chloroform).
r
D
are discussed below.
p-Methoxyphenyl
2-acetamido-2-deoxy-3,4,6-
The reaction was carried out in anhydrous acetoni-
trile as described in [2]. It is evident from the informa-
tion given in the table that the highest yields were
obtained with a 4.5-fold excess of potassium carbonate
and 0.05 or 0.01 mol of PEG per mol of substrate. How-
ever, we suggest the use of 5 mol % of the catalyst,
because these synthetic conditions provide for a shorter
reaction time.
tri-O-acetyl-b-D-glucopyranoside (VI); mp 192–
1
8
94°C; [α] –13° (c 1.0, chloroform) (lit. [8]: yield
5
46
5%; mp 195.8–196.4°C; [α] –11° (chloroform).
D
The reaction conditions for glucosamination of phenols. The
time of 100% conversion of substrate (I) and yields of glyco-
sides (V)–(VII)* are given
Only β-glycosides result from the reaction, which
1
Potassium car- PEG, Reaction Yield,
Glycoside
was confirmed by the H NMR spectra of the resulting
bonate, mol
mol
time, h
%
compounds identical to those reported in [2].
(
V)
1
0.05
0.01
0.10
0.05
0.05
0.05
8
11
3.5
4.5
3
35
50
42
46
60
45
The results reported herein are comparable with
those obtained previously for 15-crown-5 [5] and aro-
matic CEs [5], which allows us to conclude that PEG is
also an effective catalyst of β-glucosamination of phe-
nols.
(V)
4.5
4.5
4.5
4.5
4.5
(
(
(
(
V)
V)
VI)
VII)
1
Corresponding author; phone: (0652) 23-3885; fax: (0652) 23-
4
2
310; e-mail: vladimir@tnu.crimea.ua
2
Abbreviations: CE, crown ether; PEG, polyethylene glycol.
* Chloride (I)–phenol (II)–(IV) molar ratio was 1 : 1.
1
068-1620/05/3103-0300 © 2005 Pleiades Publishing, Inc.
Kur'yanov
