162
J. Pytkowicz et al. / Journal of Organometallic Chemistry 631 (2001) 157–163
(aqueous solution) was added. The suspension was
stirred until decoloration and appearance of a white
precipitate in the organic phase. The solution was
filtered and the precipitate was washed with Et2O and
dried to afford 290 mg (58%) of the expected com-
pound as a white solid.
4.3.4. (4R,5R)-1,3-bis-[(S)-1-Phenylethyl]-4,5-di-tert-
butylimidazolin-2-ylidene sil6er(I) acetate (5d)
[h]2D0= −71 (c 0.5, CH2Cl2). Anal. Calc. for
C29H41AgN2O2 (MW=557.5): C, 62.48; H, 7.41; N,
1
5.02. Found: C, 61.35; H, 7.88; N, 4.94%. H-NMR
(CDCl3) l 0.60 (s, 18H, C(CH3)3), 2.17 (d, 6H, J 7 Hz,
t
1H-NMR (CDCl3): l 0.60 (s, 18H, C(CH3)3), 2.28 (d,
CH3–CH), 2.18 (s, 3H, CH3CO2Ag), 3.15 (s, 2H, Bu–
t
6H, J 7.4 Hz, CH3–CH), 3.35 (s, 2H, Bu–CH–N),
CH–N), 4.65 (q, 2H, J 7 Hz, CH–CH3), 7.22–7.61 (m,
10H, Ph). 13C-NMR l 22.1, 22.2 (CH3–CH–Ph), 23.2,
26.6, 35.1, 59.6 (tBu–CH–N), 72.6, 72.9 (Ph–CH–N),
127.9, 128.2, 128.7, 140.8, 178.7, 194.6 (d+d, J 232
and 268 Hz, N–C–N).
4.64 (q, 2H, J 7.4 Hz, CH–CH3), 7.25–7.77 (m, 10H,
Ph), 10.21 (s, 1H, N–CHꢀN+).
4.3. Typical procedure for the synthesis of 5a–e
To a solution of imidazolinium salt 3a–e (1 mmol) in
CH2Cl2 (15 ml) was added Ag2O (0.5 mmol). The
mixture was stirred at 20 °C until complete consump-
tion of the precipitate (4–20 h), filtered through Celite
and concentrated to give quantitatively the expected
compounds as crystalline solids.
4.3.5. (4R,5R)-1,3-bis-[(S)-1-Phenylethyl]-4,5-di-tert-
butylimidazolin-2-ylidene sil6er(I) iodide (5e)
1H-NMR (CDCl3): l 0.61 (s, 18H, C(CH3)3), 2.15 (d,
t
6H, J 7.4 Hz, CH3–CH–N), 2.02 (s, 2H, Bu–CH–N),
4.66 (q, 2H, J 7.4 Hz, CH3–CH–N), 7.23–7.72 (m,
10H). 13C-NMR (DMSO-D6) l 22.1, 26, 34.9, 58.2,
72.1, 127.9, 128.4, 141.3. The carbene carbon was not
observed.
4.3.1. (4R,5R)-1,3-Dimethyl-4,5-di-tert-
butylimidazolin-2-ylidene sil6er(I) iodide (5a)
[h]2D0= −93 (c 1, CHCl3). Anal. Calc. for
C13H26AgIN2 (MW=445.1): C, 35.08; H, 5.89; N, 6.29.
5. Supplementary material
1
Found: C, 36.89; H, 6.60; N, 6.37%. H–NMR (400
MHz, DMSO-d6) l 0.87 (s, 18H, C(CH3)3), 3.21 (s, 6H,
CH3–N), 3.34 (s, 2H, CH–N). 13C-NMR (DMSO-d6) l
32.9, 41.7, 45.8, 80.5, 213.7 (N–C–N). The single crys-
tals of 5a suitable for X-ray diffraction analysis were
obtained by recrystallisation from CH2Cl2, Et2O and
pentane mixture.
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC Nos. 160043 for compound 5a and
160044 for 5b. Copies of this information may be
obtained free of charge from The Director, CCDC, 12
Union Road, Cambridge CB2 1EZ, UK (fax: +44-
1233-336-033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
4.3.2. (4R,5R)-1,3-Dibenzyl-4,5-di-tert-
butylimidazolin-2-ylidene sil6er(I) bromide (5b)
[h]2D0= −57 (c 0.68, CH2Cl2). Anal. Calc. for
C25H34AgBrN2 (MW=550.3): C, 54.56; H, 6.23; N,
Acknowledgements
1
5.09. Found: C, 55.24; H, 6.42; N, 4.89%. H-NMR
(200 MHz, CDCl3) l 0.68 (s, 18H, C(CH3)3), 3.24 (s,
2H, CH–N), 4.50 (d, 2H, J 14.5 Hz, Ph–C(H%)H–N),
5.12 (d, 2H, J 14.5 Hz, Ph–C(H)H%–N) 7.3–7.42 (m,
10H, Ph). 13C-NMR (CDCl3) l 27.3, 35.7, 56.5, 71.2,
128.8, 129.2, 129.7, 135.4, 206 (N–C–N).
J. Pytkowicz thanks the MESR for a grant. We
thank C. Guyard-Duhayon (Centre de Resolution de
Structures, Laboratoire de Chimie Inorganique et Ma-
te´riaux Mole´culaires, Universite´ P. et M. Curie) for
X-ray structures.
The single crystals of 5b suitable for X-ray diffrac-
tion analysis were obtained by recrystallisation from
CH2Cl2 and hexane mixture.
References
[1] (a) For recent reviews, see: W.A. Herrmann, C. Ko¨cher, Angew.
Chem. Int. Ed. Engl. 36 (1997) 2162;
(b) D. Bourrissou, O. Guerret, F.P. Gabba¨ı, G. Bertrand, Chem.
Rev. 100 (2000) 39.
[2] (a) W.A. Herrmann, C.-P. Reisinger, M. Spiegler, J. Organomet.
Chem. 557 (1998) 93;
4.3.3. (4R,5R)-1,3-Dipicolyl-4,5-di-tert-
butylimidazolin-2-ylidene sil6er(I) chloride (5c)
[h]2D0= −17 (c 0.9, CH2Cl2). Anal. Calc. for
C23H32AgClN4 (MW=507.8): C, 54.40; H, 6.35; N,
1
11.03. Found: C, 55.39; H, 6.71; N, 11.09%. H-NMR
(b) C. Zhang, J. Huang, M.L. Trudell, S.P. Nolan, J. Org.
Chem. 64 (1999) 3804;
(c) V. Calo`, R. Del Sole, A. Nacci, E. Schingaro, F. Scordari,
Eur. J. Org. Chem. (2000) 869;
(d) V. Calo`, A. Nacci, L. Lopez, N. Mannarini, Tetrahedron
Lett. 41 (2000) 8973;
(CDCl3): l 0.67 (s, 18H, C(CH3)3), 3.54 (s, 2H), 4.65 (d,
2H, J 14.5 Hz, N–CH–Ar), 5.03 (d, 2H, J 14.5 Hz,
N–CH%–Ar), 7.14–8.55 (m, 8H, Ar). 13C-NMR l 27.6,
36.4, 58.6, 72.8, 124.2, 124.8, 138.12, 150.4, 156.9, 197.2
(N–C–N).