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EXPERIMENTAL
All imidazol(in)ium-2-carboxylates used in this
study were prepared according to the procedure de-
scribed earlier in the literature from appropriate
commercially available imidazol(in)ium chlorides,
potassium tert-butoxide (1 M solution in toluene),
and CO2 using toluene as a reaction solvent [19a].
Their structures were unambiguously confirmed by
standard spectroscopic techniques, and the obtained
data were in agreement with the literature reports:
IPrCO2 [19b], IMesCO2 [19b], SIPrCO2 [22], and
SIMesCO2 [22].
[2] (a) Diez-Gonzalez, S.; Stevens, E. D.; Scott, N. M.;
Petersen, J. L.; Nolan, S. P. Chem Eur J 2008, 14,
158; (b) D´ıez-Gonza´lez, S.; Scott, N. M.; Nolan, S. P.
Organometallics 2006, 25, 2355; (c) Diez-Gonzalez,
S.; Kaur, H.; Zinn, F. K.; Stevens, E. D.; Nolan, S. P.
J Org Chem 2005, 70, 4784.
General Protocol for the Preparation of
[CuCl(NHC)] and [AgCl(NHC)] Complexes from
Imidazol(in)ium-2-carboxylates
[3] (a) Diez-Gonzalez, S.; Nolan, S. P. Acc Chem Res
2008, 41, 349; (b) Kaur, H.; Zinn, F. K.; Stevens, E.
D.; Nolan, S. P. Organometallics 2004, 23, 1157.
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Gunnoe, T. B. Organometallics 2007, 26, 1483;
(b) Delp, S. A.; Munro-Leighton, C.; Goj, L. A.;
Ramirez, M. A.; Gunnoe, T. B.; Petersen, J. L.; Boyle,
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C.; Blue, E. D.; Gunnoe, T. B. J Am Chem Soc 2006,
128, 1446.
[5] Diez-Gonzalez, S.; Correa, A.; Cavallo, L.; Nolan, S.
P. Chem Eur J 2006, 12, 7558.
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2007, 72, 5587; (b) Trost, B. M.; Dong, G. J Am Chem
Soc 2006, 128, 6054.
A 50-mL two-necked round-bottom flask equipped
with a magnetic stirring bar, a condenser, and a
three-way stopcock was charged with appropriate
imidazol(in)ium-2-carboxylate (1.1 mmol) and CuCl
or AgCl (1.32 mmol). The flask was purged with
argon prior to addition of degassed, dry toluene
(15 mL), and the resulting reaction mixture was
stirred at 110◦C for 12 h. Shorter reaction times re-
sulted in the formation of the desired NHC metal
complexes, albeit in lower yields. Experiments with
AgCl were carried out in the absence of light. After
that time, the reaction mixture was cooled down to
room temperature and filtered through a filter pa-
per. The filtrate was diluted with CH2Cl2 (25 mL)
and washed with H2O (2 × 15 mL). The organic
phase was dried over anhydrous MgSO4 and evapo-
rated to dryness under vacuum. The resulting crude
was dissolved in a little amount of CH2Cl2, and Et2O
was added to precipitate the product. The precipi-
tated [CuCl(NHC)] and [AgCl(NHC)] complexes as
white solids were collected by filtration and dried on
vacuum. The NMR spectra obtained for the isolated
complexes were consistent with the literature re-
ports: IPrCuCl [3b], IMesCuCl [15b], SIPrCuCl [23],
SIMesCuCl [2b], and IPrAgCl, IMesAgCl, SIPrAgCl,
and SIMesAgCl [15b],[21].
[7] Fructos, M. R.; Belderrain, T. R.; Nicasio, M. C.;
Nolan, S. P.; Kaur, H.; Diaz-Requejo, M. M.; Perez,
P. J. J Am Chem Soc 2004, 126, 10846.
[8] Lebel, H.; Davi, M.; Diez-Gonzalez, S.; Nolan, S. P. J
Org Chem 2007, 72, 144.
[9] (a) Brown, M. K.; May, T. L.; Baxter, C. A.; Hoveyda,
A. H. Angew. Chem. Int. Ed. 2007, 46, 1097; (b) Lee,
K. S.; Brown, M. K.; Hird, A. W.; Hoveyda, A. H.
J Am Chem Soc 2006, 128, 7182; (c) Martin, D.;
Kehrli, S.; d’Augustin, M.; Clavier, H.; Mauduit, M.;
Alexakis, A. J Am Chem Soc 2006, 128, 8416;
(d) Winn, C. L.; Guillen, F.; Pytkowicz, J.; Roland, S.;
Mangeney, P.; Alexakis, A. J Organomet Chem 2005,
690, 5672; (e) Van Veldhuizen, J. J.; Campbell, J. E.;
Giudici, R. E.; Hoveyda, A. H. J Am Chem Soc 2005,
127, 6877; (f) Tominaga, S.; Oi, Y.; Kato, T.; An,
D. K.; Okamoto, S. Tetrahedron Lett 2004, 45, 5585.
[10] (a) Teyssot, M. L.; Jarousse, A. S.; Chevry, A.; De
Haze, A.; Beaudoin, C.; Manin, M.; Nolan, S. P.; Diez-
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ACKNOWLEDGMENT
Apeiron Synthesis acknowledges the Operation Pro-
gramme Innovative Economy (PO IG) for financial
support within the PO IG 1.4-4.1. Programme.
[11] For a recent example of silver–NHC complex as trans-
fer agent on Rh, Pd, and Au, see: Boronat, M.; Corma,
A.; Gonzalez-Arellano, C.; Iglesias, M.; Sanchez, F.
Organometallics 2010, 29, 134.
[12] Hindi, K. M.; Panzner, M. J.; Tessier, C. A.; Cannon,
C. L.; Youngs, W. J. Chem Rev 2009, 109, 3859.
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A.; Angelici, R. J. Inorg. Chim. Acta 2006, 359, 4549;
(b) Schneider, N.; Cesar, V.; Bellemin-Laponnaz, S.;
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