Cross-coupling of organostannanes with organic iodides catalyzed by silica-supported poly[3-(2-cyanoethylsulfanyl)propylsiloxane palladium] complex under aqueous medium

Article abstract of DOI:10.1055/s-1999-2614

The cross-coupling of organostannanes with organic iodides was achieved in the presence of a catalytic amount of a silica-supported sulfur palladium complex (5 mol %) in CH₃CN/H₂O (4:1) at 80 °C for 5 h in 71-89% yields.

Full text of DOI:10.1055/s-1999-2614

LETTER
327
Cross-Coupling of Organostannanes with Organic Iodides Catalyzed by Silica-
Supported Poly[3-(2-cyanoethylsulfanyl)propylsiloxane palladium] Complex
Under Aqueous Medium
Suk-Ku Kang,* Tae-Gon Baik, Si-Young Song
Department of Chemistry and Research Institute for Basic Sciences, Sungkyunkwan University, Natural Science Campus,
Suwon 440-746, Korea
Fax +82 (331) 2907079; E-mail: skkang@chem.skku.ac.kr
Received 18 November 1998
Abstract: The cross-coupling of organostannanes with organic io-
dides was achieved in the presence of a catalytic amount of a silica-
supported sulfur palladium complex (5 mol %) in CH CN/H O (4 :
3
2
o
1
) at 80 C for 5 h in 71-89% yields.
Key words: silica-supported palladium, cross-coupling, organo-
stannanes, Stille coupling, aqueous medium
The palladium-catalyzed cross-coupling of organostan-
nanes with organic halides and triflates is known as the
1
Stille reaction and has become an extremely powerful
Scheme
tool for the formation of carbon-carbon bonds. This cou-
pling reaction has been widely applied in organic synthe-
sis due to the stability of organostannanes and its
tolerance of many functional groups. However, the limita-
tion of the Stille reaction is the forcing conditions typical-
ly at reflux in THF or dioxane and the requirement for dry
environments.
determine the optimum conditions, the coupling of 2-thie-
nylstannane (1a) with p-methoxyphenyl iodide (2b) was
examined and found that CH CN/H O (4 : 1) was the best
3
2
choice as solvent. The use of THF, DMF, and NMP gave
lower yields (20-40%). Running the reaction in CH CN/
3
In palladium-catalyzed processes, palladium catalysts are
recovered by several methods including precipitation and
o
H O (4 : 1) at 80 C for 5 h gave the coupled product 3b
2
in 89% yield. For the same reaction at room temperature
for 5 h gave the coupled product 3b in 35% yield.
2
water-soluble phosphine ligands. As an alternative, poly-
mer-supported palladium complexes having high activity
and selectivity received much attention because they can
The results of the silica-supported palladium-catalyzed
cross-coupling of organostannanes with organic iodides
are summarized in Table 1.12 The poly[3-(2-cyanoethyl-
sulfanyl)propylsiloxane palladium] complex (Si’-S-Pd)
3
be easily separated, recovered, and are reusable. Poly-
mer-supported palladium catalysts have been used for al-
4
5
lylic substitution, the Heck reaction, the Suzuki
9
a
was prepared by the procedure of Huang. The sulfur and
palladium content were 3.72 wt% and 4.63 wt%, respec-
tively. The 2-thienylstannane 1a was slowly added over 1
h to a solution of iodobenzene (2a) in the presence of Si’-
S-Pd catalyst (5 mol %) in CH CN/H O (4 : 1) and stirred
6
7
reaction, and telomerizations, etc. Alternatively, Jiang et
al, introduced the silica-supported sulfur or cyano-con-
8
taining polymeric complexes in the Heck reaction. Re-
9
cently, Huang et al. prepared some silica-supported
3
2
sulfur and cyano-containing palladium complexes and
o
at 80 C for 5 h to afford the coupled product 3a in 80%
9
a
utilized alkoxy-carboxylation and amination of aryl ha-
1
3
yield (entry 1 in Table 1). Filtration and reuse of the cat-
alyst gave the product 3a in 72% yield. The second reuse
of the catalyst gave 3a in 67% yield with 5% decrease in
yield. Under the same conditions the reaction of p-meth-
oxyphenyl iodide (2b) with 1a provided the coupled prod-
9
b
9c
9d
lide, Suzuki-type reaction, carbonyl allylation, Sono-
9
e
9f
gashira reaction, and the Heck reaction. However, to
the best of our knowledge no report for the Stille reaction
has been known using polymer-supported or silica-sup-
ported palladium complexes. In connection with our pro-
grams to carry out the cross-coupling under aqueous
conditions, we have investigated the silica-supported
palladium complex catalyzed cross-coupling of orga-
nostannanes with organic iodides, the results are summa-
rized in the Scheme.
1
4
uct 3b in 89% yield (entry 2). For the 1,4-diiodobenzene
2
c with 1a, bis-2-thienyl-substituted benzene 3c15 was
1
0
readily obtained in 78% yield (entry 3). Treatment of 2-fu-
rylstannane 1b with iodobenzene (2a) gave the coupled
product 3d in 83% yield (entry 4). Coupling of 1b with 2b
and 2c furnished the compounds 3e16 and 3f in 83 and
17
As a suitable catalyst for the Stille coupling reaction, sili-
ca-supported poly[3-(2-cyanoethylsulfanyl)propylsilox-
8
3% yields, respectively (entries 5 and 6). For the p-meth-
oxyphenylstannane 1c, iodobenzene (2a) and 1,4-diiodo-
9
a
11
ane palladium] complex was chosen. Initially, to
Synlett 1999, No. 3, 327–329 ISSN 0936-5214 © Thieme Stuttgart · New York

3
28
S.-K. Kang et al.
LETTER
benzene (2c) was successfully coupled to give 3g and 3h18 Reference and Notes
in 78 and 71% yields, respectively (entries 7 and 8). This
(
1) (a) Stille, T. K. Angew. Chem. Int. Ed. Engl. 1986, 25, 508-
24. (b) Mitchell, T. N. Synthesis 1992, 803-815. (c) Farina,
V. Pure Appl. Chem. 1996, 68, 73-38.
coupling was also applied to alkenyl- and alkynyl-substi-
tuted stannanes 1d and 1e. The alkenylstannane 1d was
reacted with iodobenzene (2a) and p-methoxyiodoben-
5
(2) Tsuji, J. Palladium Reagents and Catalysis, Wiley, Chiche-
ster, 1995, p.5 and references cited.
1
9
zene (2b) to give the substituted alkenes 3i and 3j in 73
and 75% yields (entries 9 and 10). Finally the alkynylstan-
nane 1e was smoothly coupled with 2a and 2b to afford
the coupled alkynes 3k and 3l (entries 11 and 12).
(
3) Shuttleworth, S. J.; Allin, S. M.; Sharma, P. K. Synthesis
997, 1217-1239.
4) (a) Uozumi, Y.; Danjo, H.; Hayashi, T. Tetrahedron Lett.
997, 38, 3557-3560 and reference therein. (b) Trost, B. M.;
Warner, R. W. J. Am. Chem. Soc. 1982, 104, 6112-6114.
1
(
1
(
(
c) Trost, B. M.; Runge, T. A. ibid. 1981, 103, 2485-2487.
d) Trost, B. M.; Keindn, E. ibid. 1978, 100, 7779-7781.
(
(
5) (a) Wang, P-W.; Fox, M. A. J. Org. Chem. 1994, 59, 5358-
364. (b) Andersson, C-M.; Karabelas, K.; Hallberg, A. J.
5
Org. Chem. 1985, 50, 3891-3895. (c) Jang, S-B. Tetrahedron
Lett. 1997, 38, 4421-4424. (d) Zhuangyu, Z.; Yi, P.; Honwen,
H; Tsi-yu, K. Synthesis 1991, 539-542.
6) (a) Jang, S-B. Tetrahedron Lett. 1997, 38, 1793-1796.
(
4
b) Fenger, I.; Drian, C. L. Tetrahedron Lett. 1998, 39, 4287-
290.
(
(
7) Kaneda, K.; Kurosaki, H.; Terasawa, M.; Imanaka, T.; Tera-
nishi, S. J. Org. Chem. 1981, 41, 2356-2362.
8) (a) Zhou, Y-Z.; Jiang, Y-Y. J. Organomet. Chem. 1983, 251,
3
1-37. (b) Li, X.; Liu, H.; Jiang, Y. J. Organomet. Chem.
1987, 39, 55-62.
(
9) (a) Cai, M-Z.; Song, C-S.; Huang, X. J. Chem. Soc. Perkin
Trans. I 1997, 2273-2274. (b) Cai, M-Z.; Song, C-S.; Huang,
X. Synth. Commun. 1997, 27, 361-366. (c) Cai, M-Z.; Song,
C-S.; Hung, X. Synth. Commun. 1998, 28, 693-700. (d) Cai,
M-Z.; Song, C-S.; Huang, X. Synth. Commun. 1997, 27, 3087-
3093. (e) Cai, M-Z.; Song, C-S.; Huang, X. Synth. Commun.
1997, 27, 1935-1942. (f) Cai, M-Z.; Song, C-S.; Huang, X.
Synthesis 1997, 521-523.
(
(
10) Stille coupling of water-soluble halides with the substituted
trichlorostannanes(RSnCl ) in the presence of PdCl and KOH
3
2
was effected in aqueous conditions. See, (a) Rai, R.; Aubrecht,
K. B.; Collum, D. B. Tetrahedron Lett. 1995, 36, 3111-3114.
(b) Roshchin, A. I.; Bumagin, N. A.; Beletskaya. ibid. 1995,
36, 125-128.
11) The preparation of the catalyst is as follows. Synthesis of Si-
S: To a stirred solution of fused silica (5.0 g) in toluene (120
mL) for 10 min, was added (EtO) SiC H SC H CN (5.0 g)
3
3
6
2
4
and the mixture was stirred at reflux for 48 h. To the reaction
mixture distilled water (30 mL) was added and stirred at reflux
for another 48 h and allowed to cool, then filtered and dried at
o
1
60 C in vacuo. The resulting white powder was washed with
acetone (3 x 20 mL) and dried. The sulfur content was deter-
mined to be 5.95 wt% by elemental analysis. Synthesis of Si-
S-Pd: A mixture of Si-S (2.0 g) and PdCl (0.22 g, 1.20 mmol)
2
In summary, the cross-coupling of organostannanes with
organic iodides in the presence of the silica-supported
poly[3-(2-cyanoethylsulfanyl)propylsiloxane palladium]
complex as catalyst was accomplished in aqueous medi-
um. This polymeric catalyst can be reused without much
loss of activity. This method has the advantages in separa-
tion of the product and reuse of the catalyst.
in acetone (50 mL) was heated to reflux under nitrogen for 72
h. The product was allowed to cool, then filtered. The resul-
ting gray powder was washed with distilled water (3 x 10 mL)
and acetone (3 x 10 mL) and then dried in vacuo to afford 2.04
g of Si-S-Pd. The sulfur and palladium content were 3.72 wt%
and 4.63 wt% by elemental analysis.
(
12) Satisfactory physical and spectral data were obtained in ac-
cord with the structure. Selected physical and spectral data are
as follows. 3a: TLC, SiO , EtOAc / hexanes 1 : 10, R = 0.40.
2
f
1
H NMR (400 MHz, CDCl ), δ 7.09 (dd, 1 H, J = 5.1, 3.5 Hz),
Acknowledgement
3
7
.27 (m, 2 H), 7.32 (dd, 1 H, J = 3.5, 1.1 Hz), 7.38 (m, 2 H),
-1
The generous financial support from Nondirected Research Fund of
Korea Research Foundation (1997-001-D00241) is gratefully ack-
nowledged.
7.62 (m, 2 H). IR (KBr) 3070, 1608, 1477, 832, 708 cm . MS
(m/e, relative intensity) = 162 (4), 161 (10), 160 (100), 128
(13), 116 (8), 115 (34).
1
3
b: TLC, SiO , hexanes, R = 0.21. H NMR (400 MHz,
2
f
CDCl ), δ 3.84 (s, 3 H), 6.94 (m, 2 H), 7.08 (m, 1 H), 7.28 (m,
3
2
H), 7.57 (m, 2 H). IR (KBr) 3102, 1603, 1433, 1218, 1019
Synlett 1999, No. 3, 327–329 ISSN 0936-5214 © Thieme Stuttgart · New York

LETTER
Cross-Coupling of Organostannanes with Organic Iodides
329
-
1
cm . MS (m/e, relative intensity) = 191 (12), 190 (100), 175
80), 147 (29).
d: TLC, SiO , hexanes, R = 0.44. H NMR (400 MHz,
(13) The typical procedure is as follows. To a stirred solution of io-
(
3
dobenzene (2a) (173 mg, 0.85 mmol) in CH CN/H O (4 : 1)
3
2
1
(5 mL) was added silica-supported palladium (Si-S-Pd) (10.6
2
f
o
CDCl ), δ 6.53 (m, 1 H), 6.73 (m, 1 H), 7.34 (m, 1 H), 7.45 (m,
mg, 5 mol %) and heated to 80 C and then 2-(tributylstan-
3
2
1
1
3
H), 7.53 (m, 1 H), 7.77 (m, 2 H). IR (KBr) 3075, 1600, 1463,
nyl)thiophene (1a) (317 mg, 0.85 mmol) in CH CN/H O (4 :
3
2
-1
093 cm . MS (m/e, relative intensity) = 145 (10), 144 (54),
16 (13), 115 (100), 89 (6), 63 (13), 51 (16).
1) (5 mL) was added slowly for an hour via a syringe pump.
o
The reaction mixture was stirred at 80 C for 5 h and cooled to
1
g: TLC, SiO , hexanes, R = 0.17. H NMR (400 MHz,
room temperature and saturated NaCl solution was added. The
Si-S-Pd was separated from the mixture by filtration, washed
with distilled water (2 x 10 mL), ethanol (2 x 10 mL), and
diethyl ether (2 x 10 mL). The reaction mixture was extracted
with ether and the organic layer was dried over anhydrous
2
f
CDCl ), δ 3.87 (s, 3 H), 7.01 (m, 1 H), 7.34 (m, 1 H), 7.45 (m,
3
-1
2
H), 7.58 (m, 4 H). IR (KBr) 3055, 1265 cm . MS (m/e, re-
lative intensity) = 185 (13), 184 (100), 169 (43), 141 (44), 115
34).
i: TLC, SiO , hexanes, R = 0.45. H NMR (400 MHz,
(
3
1
MgSO and evaporated in vacuo. The product was separated
2
f
4
CDCl ), δ 7.12 (s, 2 H), 7.21 (m, 2 H), 7.34 (m, 4 H), 7.48 (m,
by SiO column chromatography (EtOAc / hexanes 1 : 10, R
= 0.40) to afford the coupled product 3a (113 mg, 83%).
3
2
f
-1
4
H). IR (KBr) 3019, 1597, 1496, 1072, 962, 909, 693 cm .
MS (m/e, relative intensity) = 180 (88), 179 (100), 178 (72),
(14 Baldwin, L. J.; Pakray, S.; Castle, R.; Lee, M. L. J. Hetero-
cyclic Chem. 1985, 22, 1667-1669.
1
65 (45), 89 (32), 76(24).
1
3j: TLC, SiO , hexanes, R = 0.20. H NMR (400 MHz,
(15) (a) Reynolds, J. R.; Ruiz, J. P.; Child, A. D.; Noyak, K.; Ma-
rynick, D. S. Macromolecules 1991, 24, 678-687.
(b) Gronowitz, S.; Peters, D. Heterocycles 1990, 30, 645-658.
(16) Pelter, A.; Rowlands, M.; Clemment, G. Synthesis 1987,
51-53.
(17) Reynolds, J. R.; Child, A. D.; Ruiz, J. P.; Hong, S. Y.;
Marynick, A. D. Macromolecules 1993, 26, 2095-2103.
(18) Hart, H.; Harada, K.; Franck Du, C-J. J. Org. Chem. 1985, 50,
3104-3110.
2
f
CDCl ), δ 3.84 (s, 3 H), 6.90 (d, 2 H), 6.97 (d, 1 H), 7.07 (d, 1
3
H), 7.21 (s, 1 H), 7.35 (m, 2 H), 7.47 (m, 4 H). MS (m/e, rela-
tive intensity) = 210 (100), 195 (16), 167 (25), 165 (40), 152
(
3
23).
1
k: TLC, SiO , hexanes, R = 0.49. H NMR (400 MHz,
2
f
CDCl ), δ 7.31 (m, 6 H), 7.53 (m, 4 H). IR (KBr) 3062, 1599,
3
-1
1
499, 1071, 918, 756, 689, 535, 509 cm . MS (m/e, relative
intensity) = 179 (14), 178 (100), 176 (20), 152 (10), 89 (11),
6 (12).
7
(19) Tsukamoto, M.; Schlosser, M. Synlett 1990, 605-608.
Synlett 1999, No. 3, 327–329 ISSN 0936-5214 © Thieme Stuttgart · New York