Tandem staudinger-aza-Wittig templated reaction: De novo synthesis of sugar-ureido cryptands

Article abstract of DOI:10.1002/ejoc.200900023

A templated Staudinger-aza-Wittig tandem reaction selectively affords in one step a monocellobiosyl[bis(ureido)]di- azacrown cryptand and a bis(cellobiosyl)tetraureido[bis(di- azacrown)] cryptand. Formation of each type of cryptand was under control by Na

Full text of DOI:10.1002/ejoc.200900023

SHORT COMMUNICATION
DOI: 10.1002/ejoc.200900023
Tandem Staudinger–Aza-Wittig Templated Reaction: De Novo Synthesis of
Sugar–Ureido Cryptands
[a]
[a]
Stanislaw Porwanski and Alain Marsura*
Keywords: Cryptands / Template synthesis / Carbohydrates / Crown compounds
A templated Staudinger–aza-Wittig tandem reaction selec-
tively affords in one step a monocellobiosyl[bis(ureido)]di-
azacrown cryptand and a bis(cellobiosyl)tetraureido[bis(di-
azacrown)] cryptand. Formation of each type of cryptand was
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2009)
+
+
under control by Na or Cs template effect.
Introduction
Wittig (SAW) reaction, also known as the “phosphane
[
5]
imide” reaction. In this communication, we report results
obtained by a one-pot, template-directed macrobicycli-
sation between 1,6-diazidocellobiose and a diazacrown ether
macrocycle by using the tandem SAW reaction.
Crown ethers and azacrown ethers are, on the one hand,
important molecular receptors that are currently used in
biological model systems.[ On the other hand, sugars are
well known as versatile chiral entities that are particularly
suitable for the design of chiral receptors. Crown ethers
containing various carbohydrate moieties have received
1]
[
2]
Results and Discussion
much attention in recent years. Usually, the sugar moieties
are mono-, di- or trisaccharides,[
3a,3b]
directly incorporated
Cryptates 4 to 6 were synthesised in one pot and in fairly
good yields (40–47%) from 2,2Ј,3,3Ј,4Ј,6-hexa-O-acetyl-
into the crown macrocycle itself or grafted as pendant
[
3c,3d]
arms.
However, the number of papers related to the
1
1
,6Ј-diazido-1,6Ј-dideoxy-β--cellobiose (2) or 1,6Ј-diazido-
,6Ј-dideoxy-β--cellobiose (3) and tetraoxadiazacycloocta-
synthesis of cryptands containing carbohydrate moieties
and azacrown ethers in their structures is limited.
[4a,4b]
decane 1 by the tandem SAW reaction in anhydrous DMF
by using the alkali cation template effect. Thus, from 2 and
We wish to report an efficient one-step sequence for ac-
cess to a new type of cryptand structure incorporating bi-
functionalised disaccharidyl arms as illustrated in Figure 1.
Very recently, we realised a de novo synthesis of a bis-β-
cyclodextrin pseudocryptand[ by straightforward coup-
ling of a C-chiral diazacrown ether on monoazido peracety-
lated β-cyclodextrin by using a tandem Staudinger–aza-
3
, respectively, in the presence of Na CO monocellobiosyl-
2 3
sodium cryptates 4 and 5 were obtained. Differently, the
same reaction from 2 or 3 in the presence of Cs CO led
2
3
3d]
only to bis(cellobiosyl)cesium cryptate 6 or 7 as shown in
Scheme 1. The reaction performed without the cation tem-
plate effect afforded, as expected, a mixture of the two cryp-
tates (Scheme 1). Analysis of new compounds 2 to 7 by IR
and NMR spectroscopy, MS (ESI) and elemental analysis
revealed data that are in accordance with the proposed
structures. The IR spectra of 2 and 3 show the presence of
–1
strong absorption bands at 2148 and 2118 cm , respec-
tively, which are characteristic of the presence of azido
groups. Concerning the cryptates, the IR spectra of acety-
lated cryptates 4 and 6 show single absorption bands at
1
648 and 1655 cm–1 characteristic of the urea carbonyl
13
bonds, also confirmed by the quaternary carbon C NMR
signals at δ = 158.6 and 157.8 ppm for 4 and two signals at
δ = 156.6 and 160.0 ppm for 6. It is interesting to note that
deacetylated cryptates 5 and 7 show two absorption bands
Figure 1. Conceptual design of expected cryptand structures.
[
a] UMR 7565 SRSMC, CNRS, Nancy-Université,
5
rue A. lebrun, BP 80403, 54001 Nancy Cedex France
Fax: +33-383682345
–1
at 1701, 1637 and 1699, 1635 cm , respectively, and allow
E-mail: Alain.Marsura@pharma.uhp-nancy.fr
Supporting information for this article is available on the
WWW under http://www.eurjoc.org or from the author.
distinction between the anomeric urea carbonyl bond and
6Ј-urea carbonyl bond. This feature was confirmed by the
Eur. J. Org. Chem. 2009, 2047–2050
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2047

S. Porwanski, A. Marsura
SHORT COMMUNICATION
quaternary carbon 13C NMR signals at 161.0, 156.3 ppm reaction can produce two different macrocycles: one with
for 5 and 157.7, 157.4, 152.6 ppm for 7. However, these re- the two disaccharides in a parallel direction (i.e., 7Ј)
sults prove that coupling between the disaccharide and the (Scheme 2) and the other one with the two disaccharides in
diazacrown was effective and that a conformational equilib- an antiparallel direction (i.e., 6 and 7). Unfortunately, at
rium operates in the most flexible cryptates 6 and 7.
this point, the lack of X-ray structural data does not allow
us to conclude definitively. Anyway, it could be suggested,
on the basis of the best geometry adopted around a tem-
plating sphere, that the antiparallel arrangement is closer to
a spherical spatial organisation and should be preferred
over the parallel arrangement, which is more like a cone-
shaped spatial organisation.
3 2
Scheme 1. i = P(Ph) /CO /DMF.
Furthermore, positive ESI high-resolution mass spectra
of 4 to 7 were recorded and show the presence of mono-
charged species [M + Na] at m/z = 929.3464 for compound dem reaction. C may lead to antiparallel 7 or parallel cone-shaped
Scheme 2. Proposed reaction pathway for the templated SAW tan-
+
+
+
4
and [M + Na] and [M + H] at m/z = 677.2 and 655.2, 7Ј macrocycle.
respectively, for the corresponding deacetylated compound
. The mass spectrum of 6 is more complex, as it also shows
5
3
+
tricharged and dicharged species [M+ Na + 2Cs] at m/z
2100.9 and [M + 2Cs] at m/z = 2077.8 and mono-
charged species [M + Cs] at m/z = 1945.8, [M + Na] at m/z
Conclusions
2
+
=
+
+
In conclusion, an efficient, selective and rapid method
+
=
1835.7 and [M + H] at m/z = 1813.7. These data for the preparation of a new family of macrobicyclic and
strengthen the proposed structures for compounds 4 to 7. macrotricyclic molecular receptors has been presented. It
Considering the reaction pathway (Scheme 2) and the was demonstrated that high selectivity occurs in the reac-
mechanism of the SAW tandem reaction (with CO as the tion in the presence of sodium or cesium alkali cations and
2
[
6a–6c]
electrophile),
1,6-diazidocellobiose first affords 1,6-di- confirms that the macrocyclisation step was under the con-
isocyanatocellobiose intermediate A (as predicted by the trol of cations size. Presently, attempts to crystallise these
mechanism of the SAW reaction),[
6a–6c]
and then two nucle- compounds are being pursued. Nevertheless, we have now
ophilic additions take place simultaneously on the diisocya- started a step-by-step selective synthesis of the parallel
nate by the preorganised sodium B or cesium C diazacoron- cone-shaped macrocycle that will be achieved in the near
ates, which are in the proper conformation so as to favour future. Finally, the synthesis of new compounds incorporat-
macrocyclisation to the final cryptates. Considering the syn- ing other disaccharidyl moieties and the study of their over-
thesis of 6 and 7, it should be noted that the cyclisation all complexation properties are in progress.
2048
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© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2009, 2047–2050

Tandem Staudinger–Aza-Wittig Templated Reaction
by the addition of cyclohexane or ether, filtered and washed three
times with the same solvents. The pure product was dried in vacuo.
Experimental Section
General: All new compounds gave satisfactory spectroscopic data.
1
13
Sodium Cryptate 4: According to the general procedure, addition
of 2 (0.2 mmol, 0.129 g) to 1 (0.2 mmol, 0.052 g) in the presence of
H and C NMR spectra were recorded with a Bruker DRX-400
spectrometer, and all FTIR spectra were obtained with a Bruker
Vector22 spectrometer. HRMS (ESI) spectra in the positive ion
mode were obtained with a Bruker microTOF-Q98. Elemental
analyses were determined with a Thermofinnigan Flash EA1112
Na
2
3 F
CO afforded 4 (0.087 g, 47%) as a pure white powder. R =
0
1
.62 (AcOEt/methanol, 3:2). IR (KBr): ν˜ = 3337, 2921, 1753, 1648,
238, 1045 cm . H NMR (400 MHz, CDCl , 25 °C):δ = 6.68 (d,
3
–
1 1
J = 9.8 Hz, 1 H, NH), 6.57 (d, J = 5.6 Hz, 1 H, NH), 5.91 (br. s,
analyzer. In all experiments DMF was dried with CaSO
4
, filtered
1
3
9
H, NH), 5.79 (br. s, 1 H, NH), 5.19 (br. t, J = 9.3, 9.8 Hz, 2 H,
Ј-HAB), 5.15 (br. t, J = 9.8, 9.3 Hz, 2 H, 3-HAB), 5.06 (br. t, J =
.6, 9.8 Hz, 2 H, 4Ј-HAB), 4.99–4.86 (m, 4 H, 2Ј-HAB, 2-HAB), 4.54
off, distilled from CaH and flushed with argon to eliminate di-
methylamine. Other reagents was purchased from Sigma–Aldrich
and used as received.
2
(
br. d, J = 10.0 Hz, 2 H, 1-HAB), 4.49 (br. d, J = 8.6 Hz, 2 H, 1Ј-
H), 4.47 (br. d, J = 12.0 Hz, 2 H, 6a-HAB), 4.14–406 (m, 2 H, 6b-
AB), 3.97 (t large, J = 9.6, 9.8 Hz, 1 H, 4-H ), 3.95 (br. t, J =
.6 Hz, 1 H, 4-H ), 3.85–2.90 (m, 56 H, 5-HAB, 5Ј-HAB, 6Ј-HAB
, crown ether), 2.11–1.99 (s, 36 H, CH , acetates) ppm.
, 25 °C): δ = 170.8–169.5 (m, C=O,
2
,2Ј,3,3Ј,4Ј,6-Hexa-O-acetyl-1,6Ј-diazido-1,6Ј-dideoxy-β-
D-cellobiose
(
2
(
8
2): Sodium azide (0.276 g, 4.30 mmol) was added to a solution of
H
A
,2Ј,3,3Ј,4Ј,6-hexa-O-acetyl-6Ј-O-tosyl-1-azido-β--cellobiose[
0.329 g, 0.43 mmol) in DMF (10mL). The mixture was stirred at
0 °C for 24 h. After cooling, ethyl acetate (50 mL) was added, and
7]
9
2
B
,
4 H, CH
2
3
13
C NMR (100 MHz, CDCl
3
the mixture was washed with distilled water (2ϫ50 mL). The or-
ganic phase was dried with anhydrous sodium sulfate, and then
purified by column chromatography (silica gel; AcOEt/hexane,
acetates), 158.6, 157.8 (C=O, ureas), 100.7, 100.3 (C-1ЈAB), 80.9,
8
7
0.7 (C-1AB), 75.9, 75.8, 75.2, 74.8, 74.7, 74.6, 74.3, 74.1, 73.9, 73.3,
2.3 (C-4AB, C-5AB, C-5ЈAB, C-3AB, C-3ЈAB, C-2AB, C-2ЈAB), 70.3
6
0:40) to afford 2 (0.255 g, 92%). R
F
= 0.50 (AcOEt/hexane, 60:40).
(
2
C
C-4ЈAB), 62.9, 62.5 (C-6,6ЈAB), 50.8–42.2 (CH
0.9 (CH3AB,
2
crown ether), 21.4–
acetates) ppm. HRMS (ES): calcd. for
NaO21 [M + Na]+ 929.3486; found 929.3464.
–1
1
IR (thin film): ν˜ = 2148, 1754, 1217, 1045 cm . H NMR
(400 MHz, CDCl
3
, 25 °C): δ = 5.21 (t, J3Ј,2Ј = 9.3 Hz, J3Ј,4Ј
=
38
H
58
N
4
9
4
9
8
.6 Hz, 1 H, 3Ј-H), 5.16 (t, J3,2 = 9.3 Hz, J3,4 = 9.6 Hz, 1 H, 3-H),
.98 (t, J4Ј,3Ј = 9.6 Hz, J4Ј,5Ј = 9.6 Hz, 1 H, 4Ј-H), 4.90 (t, J2Ј,3Ј
.3 Hz, J2Ј,1Ј = 8.0 Hz, 1 H, 2Ј-H), 4.87 (t, J2,3 = 9.3 Hz, J2,1
=
=
Sodium Cryptate 5: According to the general procedure, addition
of 3 (0.2 mmol, 0.078 g) to 1 (0.2 mmol, 0.052 g) in the presence of
.8 Hz, 1 H, 2-H), 4.73 (d, J1,2 = 8.8 Hz, 1 H, 1-H), 4.57 (d, J1Ј,2Ј
8.0 Hz, 1 H, 1Ј-H), 4.55 (dd, J6a,6b = 12 Hz, J6a,5 = 1.8 Hz, 1 H, (KBr): ν˜ = 3383, 2912, 1701, 1637, 1238, 1102 cm . H NMR
a-H), 4.13 (dd, J6b,6a = 12 Hz, J6b,5 = 4.8 Hz, 1 H, 6b-H), 3.86 (t, (400 MHz, CH OD): δ = 4.70–4.66 (m, 2 H, NH), 4.51 (d, J =
2 3
Na CO afforded 5 (0.062 g, 46%) as a pure white powder. IR
–
1
1
=
6
J
J
3
3
4,3 = 9.6 Hz, J4,5 = 9.3 Hz, 1 H, 4-H), 3.70 (ddd, J5,4 = 9.3 Hz,
5,6a = 1.8 Hz, J5,6b = 4.8 Hz, 1 H, 5-H), 3.63–3.58 (m, 1 H, 5Ј-H),
.44–3.35 (m, 2 H, 6Ј-H), 2.15, 2.09, 2.07, 2.06, 2.04, 2.00 (6 s, 18
7.8 Hz, 1 H, 1Ј-H), 3.81–3.75 (m, 2 H), 3.68–3.21 (m, 24 H), 3.21
(s large, 6 H, OH), 3.15 (t, J = 10.0, 10.3 Hz, 1 H), 2.72 (br. s, 8
1
3
2 3
H, CH , crown ether) ppm. C NMR (100 MHz, CH OD): δ =
H, 6 CH
1
8
3
, Ac) ppm. 13C NMR (100 MHz, CDCl
3
, 25 °C): δ = 161.0 (C=O), 156.3 (C=O), 105.1 (C-1Ј), 83.8 (C-1), 80.6, 80.1,
70.7, 170.6, 170.1, 169.8, 169.7, 169.4 (6 C=O, Ac), 100.6 (C-1Ј),
78.2, 77.6, 75.3, 74.8, 74.2, 66.2 (C-2,2Ј, C-3,3Ј, C-4,4Ј, C-5,5Ј),
8.2 (C-1), 75.7 (C-4), 75.23 (C-5), 73.25 (C-5Ј), 73.0 (C-3), 72.6 62.2, 61.9 (C6,6Ј), 50.7–44.4 (CH crown ether) ppm. MS (ES): m/z
2
+
+
(
C-3Ј), 72.0 (C-2), 71.4 (C-2Ј), 69.2 (C-4Ј), 62.0 (C-6), 51.3 (C-6Ј), = 677.2 [M + Na ], 655.2 [M + H] . C26
1.2–20.9 (6 CH , Ac) ppm. C24
15 (644.19): calcd. C 44.72, calcd. C 43.79, H 6.50, N 7.86; found C 43.37, H 6.46, N 7.54.
H 5.00, N 13.04; found C 44.83, H 4.91, N 12.80.
4
H46ClN NaO15 (713.11):
2
3
32 6
H N O
Cesium Cryptate 6: According to the general procedure, addition
of 2 (0.2 mmol, 0.129 g) to 1 (0.2 mmol, 0.052 g) in the presence of
1,6Ј-Diazido-1,6Ј-dideoxy-β-D-cellobiose (3): Compound 2 (0.255 g,
0
.39 mmol) was added to a solution of MeONa/methanol (100 mL)
Cs
(KBr): ν˜ = 3406, 2872, 1753, 1655, 1234, 1041 cm . H NMR
(400 MHz, CDCl , 25 °C): δ = 5.32–4.81 (m, 5 H, 3-H, 3Ј-H, 4Ј-
H, 2Ј-H, 2-H), 4.55–4.40 (m, 3 H, 1-H, 1Ј-H), 3.83–3.41 (m, 30 H,
2 3
CO afforded 6 (0.171 g, 40%) as a pure white powder. IR
–
1
1
and stirred 3 h at room temperature. The mixture was then filtered
through a short column of Amberlite IRN 77 resin. The filtrate
was evaporated, and the resulting product was obtained as a white
powder (0.145 g, 95%) and used without purification. IR (KBr): ν˜
3
CH
CH
2
crown ether, 6b-H, 6Ј-H, 5-H, 5Ј-H, 4-H), 2.14–1.94 (s, 18 H,
, acetates) ppm. C NMR (100 MHz, CDCl , 25 °C): δ =
3
–1
1
13
=
J
(
3416, 2117 cm . H NMR (200 MHz, D
1,2 = 8.8 Hz, 1 H, 1-H), 4.46 (d, J1,2Ј = 7.6 Hz, 1 H, 1Ј-H), 3.93
d, J6Јa6Јb = 12.6 Hz,1 H, 6Јa-H), 3.79–3.21 (m, 11 H, 6Јb-H, 6a-
2
O, 25 °C): δ = 4.70 (d,
3
170.8–169.7 (C=O, acetates), 156.6, 160.0 (C=O, ureas), 101.3 (C-
1), 80.5 (C-1Ј), 75.4, 74.5, 74, 73.7, 73.5, 73.0, 72.0, 68.0 (C-4, C-
5, C-5Ј, C-3, C-3Ј, C-2, C-2Ј, C-4Ј), 62.9, 62.8 (C-6,6Ј), 51.1–41.1
1
3
H, 6b-H, 5-H, 5Ј-H, 4-H, 4Ј-H, 3-H, 3Ј-H, 2-H, 2Ј-H) ppm.
C
NMR (100 MHz, D
7
2
2
O): δ = 104.5 (C-1Ј), 92.0 (C-1), 79.9 (C-4),
8.7, 77.2 (C-5, C-5Ј), 76.2, 76.1 (C-3, C-3Ј), 75.1, 74.6 (C-2, C-
Ј), 72.1 (C-4Ј), 61.8 (C-6), 52.8 (C-6Ј) ppm. C12 ·0.5H
(CH
2 3
crown ether), 21.5–20.6, (CH , acetates) ppm. MS (ES): m/z
= 2100.9 [M + Na + 2Cs] +, 2077.8 [M + 2Cs] , 1968.3 [M + Na
3
2+
2
+
+
+
+
H
20
N
6
O
9
2
O
+ Cs] , 1945.8 [M + Cs] , 1835.7 [M + Na] , 1813.7 [M + H] .
HRMS (ES): calcd. for C76
found 1835.7085.
116 8
H N
NaO42 [M + Na]+ 1835.7079;
(401.32): calcd. C 35.88, H 5.23, N 20.93; found C 36.05, H 5.18,
N 20.01.
General Procedure for the Synthesis of Glycocryptands: To a flask
Cesium Cryptate 7: According to the general procedure, addition
of 3 (0.2 mmol, 0.078 g) to 1 (0.2 mmol, 0.052 g) in the presence of
(0.2 mmol) containing diazidocellobiose 2 or 3 was added a solu-
tion of triphenylphosphane (1.2 mmol) in anhydrous DMF (5 mL),
and the mixture was stirred for 1 h at room temperature. In a sec-
Cs
(KBr): ν˜ = 3384, 2916, 1699, 1635, 1101 cm . H NMR (400 MHz,
CH OD): δ = 4.64–4.66 (m, 2 H, NH), 4.63 (d, J = 8.8 Hz, 1 H,
1-H), 4.56 (d, J = 7.8 Hz, 1 H, 1Ј-H), 3.76–3.64 (m, 2 H), 3.68–
3.21 (m, 40 H) ppm. C NMR (100 MHz, CH OD): δ = 157.7,
3
157.4, 152.6 (C=O), 107.4 (C-1Ј), 84.7 (C-1), 79.5, 77.8, 77.6, 75.6,
74.8, 74.0, 73.8, 69.9 (C-2,2Ј, C-3,3Ј, C-4,4Ј, C-5,5Ј), 64.6, 63.3 (C-
2 3
CO afforded 7 (0.074 g, 22.6%) as a pure white powder. IR
–
1 1
ond flask, the diazacrown ether (0.2 mmol) and solid Na
2
CO
3
or
3
Cs CO (0.1 g) in anhydrous DMF (5 mL) were mixed, and the
2
3
1
3
mixture was stirred for 30 min. The two mixtures were combined,
and the resulting solution was stirred for 24 h at room temperature
under anhydrous CO bubbling. The final product was precipitated
2
Eur. J. Org. Chem. 2009, 2047–2050
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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2049

S. Porwanski, A. Marsura
SHORT COMMUNICATION
6
,6Ј), 50.7–44.4 (CH
2
crown ether) ppm. MS (ES): m/z = 1441.5
Stoddardt, Carbohydr. Res. 1977, 55, C1–C4; c) P. Bako, L.
Fenichel, L. Toke, B. E. Davison, J. Chem. Soc. Perkin Trans.
+
[
M + Cs] .
1
1989, 2514–2516; d) S. Menuel, J. P. Joly, B. Courcot, J.
Elysée, N. E. Ghermani, A. Marsura, Tetrahedron 2007, 63,
706–1714.
4] a) M. Pietraszkiewicz, P. Salanski, J. Jurczak, Tetrahedron 1984,
0, 2971–2973; b) M. Pietraszkiewicz, P. Salanski, J. Jurczak,
Supporting Information (see footnote on the first page of this arti-
cle): Synthesis and spectroscopic data for the precursors of 2.
1
[
[
4
Acknowledgments
J. Chem. Commun. 1983, 1184.
5] This reaction presently named the “tandem Staudinger–aza-
Wittig” reaction was early developed in collaboration with
Hungarian colleagues in the sugar and cyclodextrin series from
monoazidosaccharides and azidocyclodextrins and was initially
named the “phosphane imide” reaction with respect to the first
key reaction intermediate of the Staudinger reaction. See
ref.[
Financial support from the CNRS and the French Ministère de
l’Enseignement Supérieur et de la Recherche are gratefully ac-
knowledged. Mrs. S. Adache for elemental analyses and Mr. F. Du-
pire for ESI mass spectra and NMR spectroscopic data acquisition
are also acknowledged. The authors wish to thank Dr. J. P. Joly for
correcting the manuscript.
3d,6a–6c]
[
6] a) I. Pinter, J. Kovacs, G. Toth, Carbohydr. Res. 1995, 273, 99–
1
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1] G. W. Gokel, W. L. Leevy, M. E. Weber, Chem. Rev. 2004, 104,
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K. Pál, S. Bodor, A. Makó, L. Tóke, Tetrahedron: Asymmetry
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2
004, 15, 1589–1595; M. Ménand, J.-C. Blais, J.-M. Valéry, J.
[7] This product was synthesised by a known literature procedure;
see compound 15 and ref. 2 in the Supporting Information.
Received: January 9, 2009
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Published Online: March 12, 2009
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