Indium(I) iodide mediated efficient synthesis of selenoglycosides

Article abstract of DOI:10.1016/j.tetlet.2006.02.009

A convenient odorless methodology has been developed for the preparation of selenoglycosides through indium(I) iodide mediated cleavage of diselenides and reaction with glycosyl bromides. The yields were excellent in all cases. Retention of the configurat

Full text of DOI:10.1016/j.tetlet.2006.02.009

Tetrahedron Letters 47 (2006) 2345–2348
Indium(I) iodide mediated efficient synthesis of selenoglycosidesq
Pallavi Tiwari and Anup Kumar Misra*
Medicinal and Process Chemistry Division, Central Drug Research Institute, Chattar Manzil Palace, Lucknow 226001, UP, India
Received 22 December 2005; revised 26 January 2006; accepted 1 February 2006
Available online 20 February 2006
Abstract—A convenient odorless methodology has been developed for the preparation of selenoglycosides through indium(I) iodide
mediated cleavage of diselenides and reaction with glycosyl bromides. The yields were excellent in all cases. Retention of the con-
figuration at the anomeric center was observed in each case.
Ó 2006 Elsevier Ltd. All rights reserved.
Selenoglycosides have been used widely in biochemical
and structural investigations of glycosidases due to the
fact that naturally occurring O-glycosides are not
hydrolytically stable to the action of glycohydrolase
enzymes.1,2 Selenoglycosides have found many applica-
tions in the field of carbohydrate chemistry as very
effective and stable glycosyl donors.3–5 Selenoglycosides
can be selectively activated in the presence of thioglyco-
sides, which make them attractive in oligosaccharide
synthesis.6 They are also useful intermediates for the
preparation of functionalized glycals, C-glycosides and
glycoconjugates, etc.5,7–9 The ongoing progress in the
syntheses of complex oligosaccharides has been closely
related with the development of newer glycosylation
methods exploiting selenoglycosides as glycosyl donors.
In general, selenoglycosides are prepared by treating
halides with selenium under sodium borohydride reduc-
tion conditions10,11 or by treating a glycosyl acetate with
an arylselenol derived from the hypophosphorus acid
reduction of diphenyl diselenide in the presence of
BF3ÆOEt2.12–14 In both cases, there are several draw-
backs including the use of obnoxious reagents and
incompatibility of base-labile protecting groups under
sodium borohydride reduction conditions. Therefore,
there is a need to develop an odorless and convenient
protocol for the preparation of selenoglycosides.
and many other useful organic transformations.15 In a
recent report, indium(I) iodide was applied successfully
for the rapid preparation of unsymmetrical diorganyl
selenides via cleavage of diphenyl diselenide.16 We envi-
sioned the use of indium(I) iodide for the cleavage of
diaryl diselenides followed by reaction of the selenide
anions formed in situ with a glycosyl bromide to pro-
duce selenoglycosides, avoiding the use of any malodor-
ous reagent. In this letter, we disclose a very rapid
preparation of selenoglycosides using diaryl diselenides
mediated by indium(I) iodide (Scheme 1).
In a first set of experiments, indium(I) iodide (0.5 equiv)
was added to a mixture of diphenyl diselenide (1.0 equiv)
and acetobromo-D-glucose (2.0 equiv) in CH2Cl2 at
room temperature. To our satisfaction, the reaction
proceeded rapidly to furnish the required phenylseleno-
glycoside. Reducing the quantity of indium(I) iodide
led to an incomplete reaction, even after 24 h. Our results
with a variety of glycosyl bromides for the formation of
selenoglycosides are listed in Table 1. The use of CH3CN
or CHCl3 did not affect the yield of the product. A typical
experimental procedure is as follows: to a solution of
diphenyl diselenide (312 mg, 1.0 mmol) and per-O-acetyl-
ated glycosyl bromide (2.0 mmol) in CH2Cl2 (5.0 ml) was
In the past, indium metal and its salts have been used in
various novel rearrangements, C–C bond formations
OR1
R1O
R1O
O
OR1
R1O
R1O
R1O
O
InI
CH2Cl2/ rt
45-60 min
Br
RSeSeR
IIn(SeR)2
Keywords: Carbohydrate; Cleavage reactions; Selenoglycosides;
Organometallics; Indium(I) iodide.
q CDRI Communication No. 6908.
R1O
SeR
R = Ph, PhCH2
*
Corresponding author. Tel.: +91 522 2612411 18; fax: +91 522
2623938; e-mail: akmisra69@rediffmail.com
Scheme 1.
0040-4039/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2006.02.009

2346
P. Tiwari, A. K. Misra / Tetrahedron Letters 47 (2006) 2345–2348
Table 1. Indium iodide mediated cleavage of diselenides and their reaction with glycosyl bromides in the formation of selenoglycosides
Entry
1
Dichalconides
PhSeSePh
Glycosyl halides
Products
Time (min)
45
Yielda (%)
92
Ref.
—
OAc
O
OAc
O
AcO
AcO
AcO
AcO
AcO
AcO
Br
SePh
1
7
AcO
AcO
OAc
OAc
AcO
OAc
O
O
2
PhSeSePh
45
90
—
AcO
AcO
SePh
Br
8
2
OAc
O
OAc
AcO
AcO
AcO
AcO
O
3
4
5
PhSeSePh
PhSeSePh
PhSeSePh
40
45
40
90
88
85
4
7
7
AcO
AcO
Br
SePh
9
3
OAc
O
OAc
O
AcO
AcO
AcO
AcO
SePh
Br
NPhth
10
NPhth
4
Br
SePh
H3C
AcO
H3C
AcO
O
O
AcO
AcO
11
OAc
OAc
O
5
OAc
OAc
AcO
AcO
COOMe
Cl
COOMe
SePh
AcO
AcHN
AcO
6
7
8
9
PhSeSePh
BnSeSeBn
BnSeSeBn
BnSeSeBn
BnSeSeBn
O
50
60
60
60
60
58b
80
85
90
88
17
—
—
—
—
AcHN
AcO
AcO
12
OAc
6
OAc
O
O
AcO
AcO
AcO
AcO
AcO
1
AcO
13
Br
SeBn
AcO
AcO
OAc
OAc
OAc
O
O
AcO
AcO
AcO
14
SeBn
Br
2
OAc
OAc
O
AcO
AcO
AcO
O
AcO
AcO
AcO
Br
SeBn
3
15
OAc
O
OAc
O
AcO
AcO
AcO
AcO
10
Br
SeBn
NPhth
NPhth
4
16
a Isolated yield.
b Together with some glycal (ꢀ30%).
added InI (121 mg, 0.5 mmol) and the reaction mixture
was stirred at room temperature for appropriate time
(Table 1). After completion of the reaction (TLC;
hexane–EtOAc 1:1), the reaction mixture was diluted
with CH2Cl2 (20.0 ml). The organic layer was washed
with aq NaHCO3 and water successively, then dried
(Na2SO4) and evaporated to dryness. The crude products
were purified over SiO2 using hexane–EtOAc (8:1) as elu-
ant to furnish pure phenylselenoglycoside, as confirmed
from NMR and mass spectra.18 Known compounds gave

P. Tiwari, A. K. Misra / Tetrahedron Letters 47 (2006) 2345–2348
2347
1H NMR and 13C NMR spectra that matched the data
reported in the cited references. The reaction protocol
is equally effective for the cleavage of dibenzyl diselenide.
It is noteworthy that retention of configuration at the
anomeric center was observed in every case, which may
be due to the fact that the glycosylselenide formation
proceeds through a free radical mechanism as in the case
of samarium mediated C–C bond formation.19 To the
best of our knowledge, exclusive formation of 1,2-cis-
selenoglycosides has not been reported earlier.
16. (a) Ranu, B. C.; Mandal, T.; Samanta, S. Org. Lett. 2003,
5, 1439–1441; (b) Ranu, B. C.; Mandal, T. Synlett 2004,
1239–1242.
17. Marra, A.; Sinay, P. Carbohydr. Res. 1989, 187, 35–
¨
42.
18. Spectral data of compounds not previously reported:
Phenyl 2,3,4,6-tetra-O-acetyl-1-seleno-a-D-gluco-pyrano-
25
side (7): Yellow oil; ½aꢁD +28.3 (c 1.0, CHCl3); IR (neat):
2926, 2364, 1750, 1655, 1434, 1369, 1224, 1046, 769 cmꢂ1
;
1H NMR (200 MHz, CDCl3): d 7.53–7.43 (m, 2H,
aromatic protons), 7.23–7.15 (m, 3H, aromatic protons),
6.12 (d, J = 5.6 Hz, 1H, H-1), 5.25 (t, J = 9.5 Hz, 1H,
H-3), 4.99–4.91 (m, 2H, H-2 and H-4), 4.38 (dd, J = 12.2
and 5.0 Hz, 1H, H-6a), 4.20 (dd, J = 12.2 and 5.0 Hz, 1H,
H-6b), 3.89–3.88 (m, 1H, H-5), 2.03, 1.98, 1.96, 1.94 (4s,
12H, 4COCH3); 13C NMR (50 MHz, CDCl3): d 170.6
(2C), 170.2, 169.8, 131.9 (2C), 129.5 (2C), 129.3, 128.0,
81.2, 74.2, 71.2, 70.2, 68.5, 62.3, 21.1 (2C), 21.0 (2C), 20.9;
ESI-MS: m/z = 511 [M+Na]. Anal. Calcd for C20H24O9Se
(488): C, 49.29; H, 4.96. Found: C, 49.05; H, 5.12.
In summary, an odorless methodology has been devel-
oped for the exclusive preparation of a series of 1,2-
cis-selenoglycosides through indium(I) iodide mediated
reduction of diorganyl diselenides followed by reaction
with glycosyl halides. Fast, stereoselective formation of
selenoglycosides without formation of anomerized prod-
ucts, avoiding the use of obnoxious selenols under a
neutral reaction conditions makes this protocol superior
to the existing methodologies in this area.
Phenyl 2,3,4,6-tetra-O-acetyl-1-seleno-a-D-galacto-pyrano-
25
side (8): Yellow oil; ½aꢁD +72.3 (c 1.0, CHCl3); IR (neat):
1
2926, 1748, 1654, 1370, 1225, 1052, 771 cmꢂ1; H NMR
(200 MHz, CDCl3): d 7.56–7.52 (m, 2H, aromatic pro-
tons), 7.24–7.16 (m, 3H, aromatic protons), 5.29 (d,
J = 2.0 Hz, 1H, H-1), 5.14 (t, J = 9.9 Hz, 1H, H-2), 4.90
(dd, J = 9.8 and 3.2 Hz, 1H, H-3), 4.80 (br s, 1H, H-4),
4.06–3.96 (m, 2H, H-6ab), 3.85–3.79 (m, 1H, H-5), 2.01 (s,
6H, 2COCH3), 1.98, 1.97 (2s, 6H, 2COCH3); 13C NMR
(50 MHz, CDCl3): d 170.0 (2C), 169.8, 169.2, 135.5–127.8
(aromatic carbons), 81.9, 75.8, 72.1, 68.4, 67.5, 61.7, 21.1
(2C), 20.8 (2C); ESI-MS: m/z = 511 [M+Na]. Anal. Calcd
for C20H24O9Se (488): C, 49.29; H, 4.96. Found: C, 49.08;
H, 5.15.
Acknowledgements
Instrumentation facilities from SAIF, CDRI are grate-
fully acknowledged. P.T. thanks CSIR, New Delhi, for
providing a senior research fellowship. This project
was funded by the Department of Science and Techno-
logy (DST), New Delhi (Project No. SR/FTP/CSA-10/
2002), India.
Benzyl 2,3,4,6-tetra-O-acetyl-1-seleno-a-D-gluco-pyrano-
25
References and notes
side (13): Yellow oil; ½aꢁD +74.6 (c 1.0, CHCl3); IR (neat):
2930, 1751, 1432, 1370, 1225, 1041, 910, 759 cmꢂ1 1H
;
NMR (200 MHz, CDCl3): d 7.33–7.25 (m, 5H, aromatic
protons), 5.87 (d, J = 5.7 Hz, 1H, H-1), 5.28 (t,
J = 9.5 Hz, 1H, H-3), 5.01 (t, J = 9.5 Hz, 1H, H-2) 4.94
(dd, J = 9.9 and 5.7 Hz, 1H, H-4), 4.34–4.19 (m, 2H, H-5,
H-6a), 3.92–3.86 (m, 1H, H-6b), 3.75 (q, J = 12 Hz, 2H,
SeCH2Ph), 2.08, 2.02 (2s, 6H,2COCH3) 1.99 (s, 6H,
2COCH3); 13C NMR (50 MHz, CDCl3): d 170.1 (2C),
169.9, 169.6, 129.2 (2C), 129.0, 128.9 (3C), 78.8, 76.3, 71.7,
71.2, 69.8, 68.6, 26.6, 21.0 (2C), 20.9 (2C), 20.9; ESI-MS:
m/z = 525 [M+Na]. Anal. Calcd for C21H26O9Se (502): C,
50.31; H, 5.23. Found: C, 50.10; H, 5.50.
1. Mehta, S.; Andrews, J. S.; Johnston, B. D.; Svensson, B.;
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289–292.
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3276.
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hedron 2004, 60, 8411–8419.
Benzyl 2,3,4,6-tetra-O-acetyl-1-seleno-a-D-galacto-pyrano-
25
side (14): Yellow oil; ½aꢁD +92.3 (c 1.0, CHCl3); IR (neat):
2927, 1748, 1454, 1370, 1223, 1060, 913, 766 cmꢂ1 1H
;
NMR (200 MHz, CDCl3): d 7.33–7.22 (m, 5H, aromatic
protons), 5.91 (br s, 1H, H-3), 5.44 (br s, 1H, H-1), 5.17
(br s, 2H, H-2 and H-4), 4.56–4.51 (m, 1H, H-5) 4.15–4.04
(m, 2H, H-6ab), 3.80–3.69 (m, 2H, SeCH2Ph), 2.14, 2.05,
2.00, 1.98 (4s, 12H, 4COCH3); 13C NMR (50 MHz,
CDCl3): d 170.1, 170.0 169.8, (2C), 128.9, 128.8 (2C),
128.6 (2C), 126.9, 78.3, 69.1, 68.3, 68.0, 67.5, 61.6, 25.7,
20.5 (2C), 20.4 (2C); ESI-MS: m/z = 525 [M+Na]. Anal.
Calcd for C21H26O9Se (502): C, 50.31; H, 5.23. Found: C,
50.08; H, 5.52.
8. Bravo, F.; Kassou, M.; Diaz, Y.; Castillon, S. Carbohydr.
Res. 2001, 336, 83–97.
9. Grant, L.; Liu, Y.; Walsh, K. E.; Walter, D. S.; Gallagher,
T. Org. Lett. 2002, 4, 4623–4625.
10. Witczak, Z. J.; Whistler, R. L. Heterocycles 1982, 19,
1719–1734.
11. Crich, D.; Suk, D.-H.; Sun, S. Tetrahedron: Asymmetry
2003, 14, 2861–2864.
12. Mehta, S.; Pinto, B. M. Tetrahedron Lett. 1991, 32, 4435–
4438.
Benzyl 2,3,4,6-tetra-O-acetyl-1-seleno-a-D-manno-pyrano-
13. Aloui, M.; Chambers, D. J.; Cumpstey, I.; Fairbanks, A.
J.; Redgrave, A. J.; Seward, C. M. P. Chem. Eur. J. 2002,
8, 2608–2621.
14. Gerz, M.; Matter, H.; Kessler, H. Angew. Chem., Int. Ed.
Engl. 1993, 32, 269–271.
15. (a) Li, C.-J.; Chan, T. H. Tetrahedron 1999, 55, 11149–
11176; (b) Ranu, B. C. Eur. J. Org. Chem. 2000, 2347–
2356.
25
side (15): Oil; ½aꢁD +126.8 (c 1.0, CHCl3); IR (neat):
2972, 2362, 1742, 1598, 1373, 1246, 1107, 1050, 977,
1
756 cmꢂ1; H NMR (200 MHz, CDCl3): d 7.28–7.09 (m,
5H, aromatic protons), 5.35 (br s, 1H, H-2), 5.24 (br s, 1H,
H-1), 5.20–5.16 (m, 2H, H-3 and H-4), 4.24–4.20 (m, 2H,
H-6ab), 3.91–3.85 (m, 1H, H-5) 3.75 (q, J = 12.0 Hz, 2H,
SeCH2Ph), 2.07, 2.03, 1.98, 1.90 (4s, 12H, 4COCH3); 13C

2348
P. Tiwari, A. K. Misra / Tetrahedron Letters 47 (2006) 2345–2348
NMR (50 MHz, CDCl3): d 170.2, 169.4 (2C), 169.3, 137.6,
4.50 (t, J = 10.5 Hz, 1H, H-3), 4.30 (dd, J = 12.3 and
4.8 Hz, 1H, H-6a), 4.12 (dd, J = 12.3 and 2.1 Hz, 1H, H-
6b) 3.95 (q, J = 11.6 Hz, 2H, SeCH2Ph), 3.75–3.72 (m, 1H,
H-5), 2.12, 2.05, 1.87 (3s, 9H, 3 COCH3); 13C NMR
(50 MHz, CDCl3): d 170.7, 170.1, 169.5, 166.5 (2C), 136.9,
134.3, 132.5, 130.9, 129.8, 129.0 (2C), 128.5 (2C), 126.7,
123.7 (2C), 77.2, 75.8, 71.3, 68.8, 62.2, 54.4, 26.9, 20.8,
20.6, 20.4; ESI-MS: m/z = 612 [M+Na]. Anal. Calcd for
C27H27NO9Se (589): C, 55.11; H, 4.62. Found: C, 54.90;
H, 4.75.
128.6 (2C), 128.3 (2C), 126.8, 77.3, 70.8, 70.3, 69.7, 65.8,
61.8, 27.4, 20.5, 20.4, 20.3, 20.2; ESI-MS: m/z = 525
[M+Na]. Anal. Calcd for C21H26O9Se (502): C, 50.31; H,
5.23. Found: C, 50.10; H, 5.50.
Benzyl 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-1-seleno-
25
b-D-glucopyranoside (16): Yellow oil; ½aꢁD +4.6 (c 1.0,
CHCl3); IR (neat): 2929, 1724, 1378, 1218, 1077,
1
767 cmꢂ1; H NMR (200 MHz, CDCl3): d 7.86–7.72 (m,
4H, aromatic protons), 7.36–7.23 (m, 5H, aromatic
protons), 5.79 (t, J = 9.9 Hz, 1H, H-3), 5.55 (d,
J = 10.8 Hz, 1H, H-1), 5.18 (t, J = 9.9 Hz, 1H, H-4),
19. Du, Y.; Linhardt, R. J. Tetrahedron 1998, 54, 9913–
9959.