9
036
X. Huang, S.-R. Sheng / Tetrahedron Letters 42 (2001) 9035–9037
(
Table 1). The polymer-supported selenophosphorane 2
ketone 4a was obtained in 74% yield under the same
reaction conditions (second run), and in 70% yield after
the second recycle (i.e. third run). During the course of
these successive runs, the color of the selenenyl bromide
resin gradually changed from deep red to red. It was
shown that recycling 2–3 times led to a gradual deterio-
ration of the resin.
containing 0.96–0.97 mmol P/g was treated with an
aldehyde to form a yellow vinylic selenide resin 3
containing 1.15–1.16 mmol Se per gram (9.1–9.2% Se)
and no phosphorus by microanalysis. The infrared
spectrum of the resin 3 showed strong CꢀC absorptions
at 1600 and 1584 cm . In the IR spectrum of the resin
containing the nitro-group, there were two strong
peaks, for NO , at 1521 and 1452 cm . On treatment
−
1
−
1
In conclusion, we have developed a SPOS route to
ketones and aldehydes in good yields and purities.
Although an excess of the reagents is required, simple
work-up procedures take the place of the time-consum-
ing isolation and purification steps in the solution-
phase synthesis.
2
of the resin 3 with HgCl /CH CN/H O, no cleavage
2
3
2
took place. Cleavage with TFA gave low yields and
purities of the final products. After some screening, we
found that when TFA/CH Cl (1/10) was used, the
2
2
expected ketones were obtained in good yields and high
purities. When R was larger than CH , the yields of
8
1
3
ketones (4f and 4g) were poor.
Acknowledgements
1
The vinylic selenide resin 3, where R was hydrogen,
did not hydrolyze to an aldehyde under the above
transformation conditions. However, hydrolysis could
be easily achieved by reacting the vinlyic selenide resin
We gratefully acknowledge financial support from the
National Science Foundation of China (No. 29932020).
3
with dry hydrogen bromide in DCM, followed by
solvolysis to the corresponding aldehyde in the presence
References
9
of anhydrous DMSO. At the same time, the polymer-
supported selenium bromide could be regenerated.
1
. For recent reviews on SPOS, see: (a) Brown, R. C. D. J.
Chem. Soc., Perkin Trans. 1. 1998, 3293–3320; (b)
Fruchtel, J. S.; Jung, G. Angew. Chem., Int. Ed. 1996, 35,
When the hydrolysis cleavage of resins 3 was used
(
route a), a deep yellow diphenyl diselenide resin 5 was
1
9
7–42; (c) Lorsbach, B. A.; Kurth, M. J. Chem. Rev. 1999,
9, 1549–1581; (d) Guillier, F.; Orain, D.; Bradley, M.
obtained after washing and drying and its infrared
−
1
spectrum included an SeꢁSe absorption at 1260 cm .
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Ottenhijm, H. C. J.; Rees, D. C. Tetrahedron 1997, 53,
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2
3
at room temperature afforded the polymer-bound sele-
nium bromide as red beads, which possessed infrared
spectroscopic data identical to those of the initial sele-
nenyl bromide resin. The loading of the resin 5 was
5643–5678.
2
. (a) Selenium Reagents and Intermediates in Organic Syn-
thesis; Paulmier, C., Ed.; Pergamon Press: Oxford, 1986;
(
b) Reach, H. J. Org. Chem. 1974, 39, 428–429; (c) Nico-
1
.12–1.15 mmol Se/g, which was confirmed by the
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3. Petragnani, N.; Rodrigues, R.; Comasseto, J. V. J.
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a
Table 1. The yield and purity of ketones and aldehydes
1
978, 152, 295–304.
. Dumont, W.; Sevrin, M.; Krief, A. Tetrahedron Lett. 1978,
83–186.
Entry
R1
R2
Yield (%)b
Purity (%)c
5
6
1
4
4
4
4
4
4
4
7
7
7
7
7
7
a
b
c
d
e
f
g
a
b
c
d
e
f
CH3
CH3
CH3
CH3
CH3
C H
80
77
82
78
70
45
40
76
78
75
72
72
73
90
92
93
91
88
—
—
90
91
93
90
91
90
6
5
. (a) Nicolaou, K.-C.; Pastor, J.; Barluenga, S.; Winssinger,
N. Chem. Commun. 1998, 1947–1949. For preparation of
related selenium-based resins, see: (b) Michels, R.; Kato,
M.; Heitz, W. Makromol. Chem. 1976, 177, 2311–2320; (c)
Ruhland, T.; Andersen, K.; Pedersen, H. J. Org. Chem.
1998, 63, 9204–9211; (d) Fujita, K.; Watanabe, K.; Oishi,
A.; Ikeda, Y.; Taguchi, Y. Synlett 1999, 11, 1760–1762.
7. (a) Nicolaou, K. C.; Pfefferkorn, J. A.; Cao, G.-Q. Angew.
Chem., Int. Ed. 2000, 39, 734–739; (b) Nicolaou, K. C.;
Cao, G.-Q.; Pfefferkorn, J. A. Angew. Chem., Int. Ed.
p-CH C H
p-NO C H
4
p-Cl C H
CH (CH )
3
6
4
2
6
6
4
3
2 2
C H
C H
2
5
6
5
5
5
C H
C H
6
5
6
H
H
H
H
H
H
C H
6
p-CH C H
p-NO C H
p-ClC H
p-CH OC H
3
6
4
2
6
4
6
4
3
6
4
2
000, 39, 739–743; (c) Nicolaou, K. C.; Pfefferkorn, J. A.;
CH (CH )
3
2 2
Cao, G.-Q.; Kim, S.; Kessabi, J. Org. Lett. 1999, 1,
807–810; (d) Nicolaou, K. C.; Winssinger, N.; Hughes, R.;
Smethurst, C.; Cho, S. Y. Angew. Chem., Int. Ed. 2000, 39,
1084–1088; (e) Nicolaou, K. C.; Mitchell, H. J.; Fylaktaki-
dou, K. C.; Suzuki, H.; Rodriguez, R. M. Angew. Chem.,
a
All compounds are known and their structures were determined by
H NMR and IR.
1
b
c
Overall yields based on selenenyl bromide resin (1.18 mmol/g).
Determined by 1H NMR of the crude cleavage product.