3432 Bull. Korean Chem. Soc. 2012, Vol. 33, No. 10
Notes
couplings of 4,6-dichloropyrimidine with aryl boronic acids
also gave excellent yields (entries 10-11).
Science Foundation of China (No. 20902043) and Luoyang
Tackle Key Problem of Science and Technology (No.
1001060A) for financial support of this work.
In conclusion, we have prepared and characterized a new
NHC-phosphine palladium(II) complex 2. Its catalytic activity
was evaluated in the Suzuki reaction. 2 was found to be very
efficient catalyst for this reaction of aryl chlorides.
References
1. Suzuki, A. J. Organomet. Chem. 2002, 653, 83.
2. Phan, N. T. S.; Sluys, M. V. D.; Jones, C. W. Adv. Synth. Catal.
2006, 348, 609.
Experimental Section
3. Littke, A. F.; Fu, G. C. Angew. Chem. Int. Ed. 2002, 41, 6338.
4. Altman, R. A.; Buchwald, S. L. Nature Protocols 2007, 2, 3115.
5. Fu, G. C. Acc. Chem. Res. 2008, 41, 1555.
Materials and Measurement. The dimer 1 was prepared
according to published procedures.16 All other chemicals
were used as purchased. Elemental analyses were determin-
ed with a Thermo Flash EA 1112 elemental analyzer. IR
spectra were collected on a Bruker VECTOR22 spectro-
photometer using KBr pellets. 1H NMR spectra were record-
ed on a Bruker DPX-400 spectrometer in CDCl3 with TMS
as an internal standard. Crystallographic data were collected
on a Bruker SMART APEX-II CCD diffractometer. CCDC
reference number 886745 for 2. The data can be obtained
free of charge from The Cambridge Crystallographic Data
6. Scott, N. M.; Nolan, S. P. N-Heterocyclic Carbenes in Synthesis;
Wiley-VCH: Weinheim, 2006.
7. Fortman, G. C.; Nolan, S. P. Chem. Soc. Rev. 2011, 40, 5151.
8. Herrmann, W. A.; Böhm, V. P. W.; Gstöttmayt, C. W. K.; Grosche,
M.; Reisinger, C. P.; Weskamp, T. J. Organomet. Chem. 2001,
617-618, 616.
9. Touré, B. B.; Lane, B. S.; Sames, D. Org. Lett. 2006, 8, 1979.
10. Baker, M. V.; Brown, D. H.; Hesler, V. J.; Skelton, B. W.; White,
A. H. Organometallics 2007, 26, 250.
11. Magill, A. M.; Yates, B. F.; Cavell, K. J.; Skelton, B. W.; White,
A. H. Dalton Trans. 2007, 3398.
12. Liao, C. Y.; Chan, K. T.; Tu, C. Y.; Chang, Y. W.; Hu, C. H.; Lee,
H. M. Chem. Eur. J. 2009, 15, 405.
Pd[(C3N2H2)-(C6H4-OCH3)2]PCy3I2 (2): A solution of 1
(0.1 mmol) and ligand PCy3 (0.22 mmol) in CH2Cl2 (10 mL)
was stirred at room temperature for 1 hour. The product was
separated by passing through a short silica gel column with
CH2Cl2 as eluent. The second band was collected and
13. Mesnager, J.; Lammel, P.; Jeanneau, E.; Pinel, C. Appl. Catal. A:
Gen. 2009, 368, 22.
14. Fantasia, S.; Egbert, J. D.; Jurèík, V.; Cazin, C. S. J.; Jacobsen, H.;
Cavallo, L.; Heinekey, D. M.; Nolan, S. P. Angew. Chem. Int. Ed.
2009, 48, 5182.
−1
afforded complex 2. Yield 70%. IR (KBr, cm ): 2922, 2847,
15. Ellul, C. E.; Reed, G.; Mahon, M. F.; Pascu, S. I.; Whittlesey, M.
K. Organometallics 2010, 29, 4097.
1614, 1513, 1459, 1441, 1343, 1287, 1251, 1174, 1089,
1028, 941, 915, 835, 736, 688. 1H NMR (400 MHz, CDCl3)
δ 7.93 (d, J = 8.4 Hz, 4H, Ar-H), 7.30 (s, 2H, NCHCHN),
6.98 (d, J = 8.4 Hz, 4H, Ar-H), 3.84 (s, 6H, -OCH3), 2.48 (m,
3H, P(CHC5H10)3), 1.75 (m, 15H, P(C6H11)3), 1.42 (m, 6H,
P(C6H11)3), 1.21 (m, 9H, P(C6H11)3). Anal. Calc. for
C35H49I2N2O2PPd: C, 45.64; H, 5.36; N, 3.04. Found: C,
45.89; H, 5.17; N, 3.23.
16. Cai, X.; Majumdar, S.; Fortman, G. C.; Cazin, C. S. J.; Slawin, A.
M. Z.; Lhermitte, C.; Prabhakar, R.; Germain, M. E.; Palluccio, T.;
Nolan, S. P.; Rybak-Akimova, E. V.; Temprado, M.; Captain, B.;
Hoff, C. D. J. Am. Chem. Soc. 2011, 133, 1290.
17. Xu, C.; Wang, Z. Q.; Fu, W. J.; Lou, X. H.; Li, Y. F.; Cen, F. F.;
Ma, H. J.; Ji, B. M. Organometallics 2009, 28, 1909.
18. Xu, C.; Zhang, Y. P.; Wang, Z. Q.; Fu, W. J.; Hao, X. Q.; Xu, Y.;
Ji, B. M. Chem. Commun. 2010, 6852.
19. Xu, C.; Wang, Z. Q.; Li, Z.; Wang, W. Z.; Hao, X. Q.; Fu, W. J.;
Gong, J. F.; Ji, B. M.; Song, M. P. Organometallics 2012, 31, 798.
20. Xu, C.; Duan, L. M.; Li, Z.; Li, H. M.; Lou, X. H.; Wang, Z. Q.;
Fan, Y. T. Bull. Korean. Chem. Soc. 2012, 33, 1794.
21. Xu, C.; Hao, X. Q.; Li, Z.; Dong, X. M.; Duan, L. M.; Wang, Z.
Q.;Ji, B. M.; Song, M. P. Inorg. Chem. Commun. 2012, 17, 34.
22. Brammer, L.; Bruton, E. A.; Sherwood, P. Cryst. Growth Des.
2001, 1, 277.
General Procedure for the Coupling Reaction of Aryl
Chlorides. In a Schlenk tube, a mixture of the prescribed
amount of catalyst, aryl chloride (1.0 mmol), aryl boronic
acid (1.5-3.0 mmol) and the selected Cs2CO3 (1.5-3.0 mmol)
in solvent (5 mL) was evacuated and charged with nitrogen.
The reaction mixture was then placed in an oil bath and
o
heated at 110 C for 12 h. After being cooled, the mixture
23. Nangia, A. CrystEngComm 2002, 4, 93.
24. Janiak, C. Dalton Trans. 2000, 3885.
was extracted with dry diethyl ether and evaporated, the pure
products were isolated by flash chromatography on silica gel
25. Kotha, S.; Lahiri, K.; Kashinath, D. Tetrahedron 2002, 58, 9633.
26. Rossi, R.; Bellina, F.; Lessi, M. Adv. Synth. Catal. 2012, 354,
1181.
1
and identified by comparing melting points or H NMR
spectra.
27. Handy, S. T.; Wilson, T.; Muth, A. J. Org. Chem. 2007, 72, 8496.
28. Qing, F. L.; Wang, R. W.; Li, B. H.; Zheng, X.; Meng, W. D. J.
Fluorine Chem. 2003, 120, 21.
Acknowledgments. We are grateful to the National Natural