LETTER
Suzuki–Miyaura Cross-Couplings of Arenediazonium Salts
2413
Table 3 Cross-Couplings of Arenediazonium Tetrafluoroborate Salts and Arylboronic Acids Catalyzed by the Polystyrene-Supported NHC–
a
Pd Catalyst (continued)
catalyst 1 (2 mol% Pd)
Ar1 N2 BF4 + Ar2 B(OH)2
Ar1 Ar2
EtOH, r.t., 8–12 h
Entry Ar1
Ar2
4-MeC H
Product
Time (h)
10
Yield (%)b
80
Mp (°C)
1
1
2
3
4-MeOC H4
108–10914
6
6
4
MeO
O2N
Me
3-NO C H
4-MeOC H
8
91
79–8012
2
6
4
6
4
OMe
1
1
4
5
4-MeC H4
4-MeOC H
10
10
87
87
108–10914
89–9014
6
6
4
4
MeO
Me
Ph
Ph
4-MeOC H
6
OMe
O2N
O2N
1
6
7
3-NO C H
4
12
12
82
82
59–6011,12
79–8012
2
6
1
4-MeOC H4
3-NO C H
2 6 4
6
OMe
a
Reaction conditions: arenediazonium tetrafluoroborate (0.5 mmol), arylboronic acid (1 mmol), catalyst (100 mg, 10 mmol Pd), EtOH (5 mL),
r.t.
b
c
Isolated by silica gel column chromatography and based on arenediazonium tetrafluoroborate.
Self-coupling byproduct of phenylboronic acid in parenthesis was detected by GC-MS. In this case the self-coupling byproduct could not be
separated from cross-coupling product by silica gel column chromatography.
In conclusion, we have disclosed for the first time that the
Suzuki–Miyaura cross-couplings of arenediazonium
tetrafluoroborate salts and arylboronic acids could be
catalyzed by a recyclable polystyrene-supported NHC–Pd
(
H.; Chan, A. S. C. Chem. Commun. 2004, 2336.
c) Kwong, F. Y.; Lam, W. H.; Yeung, C. H.; Chan, K. S.;
Chan, A. S. C. Chem. Commun. 2004, 1922.
4) Venturello, C.; D’Aloisio, R. Synthesis 1979, 283.
5) (a) Darses, S.; Jeffery, T.; Genêt, J. P.; Brayer, J. L.;
Demoute, J. P. Tetrahedron Lett. 1996, 37, 3857.
(
(
catalyst. The supported catalyst manifests its high stability
and recyclability, and can be reused ten times while still
retaining high activity. Other advantages of this method
include good substrate generality, mild reaction condi-
tions without the need of inert-gas protection, and experi-
mentally operational ease.
(b) Sengupta, S.; Bhattacharyya, S. J. Org. Chem. 1997, 62,
3405. (c) Darses, S.; Genêt, J. P.; Brayer, J. L.; Demoute, J.
P. Tetrahedron Lett. 1997, 38, 4393. (d) Darses, S.;
Michaud, G.; Genêt, J. P. Eur. J. Org. Chem. 1999, 1875.
(e) Andrus, M. B.; Song, C. Org. Lett. 2001, 3, 3761.
(
f) Selvakumar, K.; Zapf, A.; Spannenberg, A.; Beller, M.
Chem. Eur. J. 2002, 8, 3901. (g) Dai, M.; Liang, B.; Wang,
C.; Chen, J.; Yang, Z. Org. Lett. 2004, 6, 221.
6) For a recent review on diazonium salts as substrates in
palladium-catalyzed cross-coupling reactions, see: Roglans,
A.; Pla-Quintana, A.; Moreno-Mañas, M. Chem. Rev. 2006,
106, 4622; and references cited therein.
Acknowledgment
(
We are grateful to the National Natural Science Foundation of
China (No. 20372049) and Chengdu Key Technologies R&D Pro-
gram (No. 06GGYB888GX). We also thank Analytical & Testing
Center of Sichuan University for support in NMR and ICP–MS
analyses.
(7) Gallo, V.; Mastrorilli, P.; Nobile, C. F.; Paolillo, R.;
Taccardi, N. Eur. J. Inorg. Chem. 2005, 582.
(
8) (a) Lebel, H.; Janes, M. K.; Charette, A. B.; Nolan, S. P. J.
Am. Chem. Soc. 2004, 126, 5046. (b) Gstöttmayr, C. W. K.;
Böhm, V. P. W.; Herdtweck, E.; Grosche, M.; Herrmann, W.
A. Angew. Chem. Int. Ed. 2002, 41, 1363.
References and Notes
(
(
(
1) (a) Hassan, J.; Sévignon, M.; Gozzi, C.; Schulz, E.; Lemaire,
M. Chem. Rev. 2002, 102, 1359. (b) Kohta, S.; Lahiri, K.;
Kashinath, D. Tetrahedron 2002, 58, 9633.
(
9) For silica- and polymer-supported NHC–Rh complexes for
the addition of arylboronic acids to aldehydes, see:
(
a) Özdemir, I.; Gürbüz, N.; Seçkin, T.; Çetinkaya, B. Appl.
2) For recent reviews, see: (a) Miyaura, N. Top. Curr. Chem.
Organomet. Chem. 2005, 19, 633. (b) Yan, C.; Zeng, X.;
Zhang, W.; Luo, M. J. Organomet. Chem. 2006, 691, 3391.
For supported NHC–Ru complexes in ring-closing
2002, 219, 11. (b) Miyaura, N. J. Organomet. Chem. 2002,
653, 54.
3) (a) Navarro, O.; Kelly, R. A.; Nolan, S. P. J. Am. Chem. Soc.
003, 125, 16194. (b) Kwong, F. Y.; Chan, K. S.; Yeung, C.
metathesis, see: (c) Herrmann, W. A. Angew. Chem. Int. Ed.
2
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