T. Wenderski et al. / Tetrahedron Letters 45 (2004) 6851–6853
6853
data for all compounds are available. The supple-
mentary data is available online with the paper in
ScienceDirect. Crystallographic data (excluding struc-
ture factors) for the structures in this paper have been
deposited with the Cambridge Crystallographic Data
Centre as supplementary publication number CCDC
234276. Copies of the data can be obtained, free of
charge, on application to CCDC, 12 Union Road, Cam-
bridge CB2 1EZ, UK (Fax: +44(0) 1223 336033 or
e-mail: deposit@ccdc.cam.ac.uk).
References and notes
1. Hartwig, J. F. Angew. Chem., Int. Ed. 1998, 37,
2046–2067.
2. Wolfe, J. P.; Wagaw, S.; Marcoux, J.-F.; Buchwald, S. L.
Acc. Chem. Res. 1998, 31, 805–818.
3. (a) Viciu, M. S.; Kissling, R. M.; Stevens, E. D.; Nolan,
S. P. Org. Lett. 2002, 4, 2229–2231; (b) Stauffer, S. R.;
Lee, S. W.; Stambuli, J. P.; Hauck, S. I.; Hartwig, J. F.
Org. Lett. 2000, 2, 1423.
Figure 1. ORTEP drawing of azophenine derivative 11c. Selected
˚
bond lengths (A): N(1)–C(1) 1.312(4); N(2)–C(2) 1.339(4); C(1)–C(2)
1.498(4); C(2)–C(3) 1.378(4); C(3)–C(1A) 1.398(4). Selected bond
angles (°): N(1)–C(1)–C(2) 115.2(3); C(1)–C(2)–N(2) 114.6(3); N(2)–
C(2)–C(3) 125.6(3).
4. (a) Clemo, G. R.; Perkin, W. H.; Robinson, R. J. Chem.
Soc. 1924, 1751–1804; (b) Bourson, J. Bull. Soc. Chim. Fr.
1970, 5, 1867–1872; (c) Chakrabarty, M.; Batabyal, A.;
Khasnobis, S. Synth. Commun. 2000, 30, 3651–3668.
5. (a) Olivier Baudoin, O.; Teulade-Fichou, M.-P.; Vigneron,
J.-P.; Lehn, J.-M. J. Org. Chem. 1997, 62, 5458–5470; (b)
Trinks, U.; Buchdunger, E.; Furet, P.; Kump, W.; Mett,
H.; Meyer, T.; Mueller, M.; Regenass, U.; Rihs, G.;
Lydon, N.; Traxler, P. J. Med. Chem. 1994, 37, 1015–1027.
6. The general procedure was as follows: Under an inert
atmosphere, Pd(OAc)2 (4mol%; based on dibromobenz-
ene) and PtBu3 (12mol%) were added to toluene and the
mixture stirred for about 5min until the Pd(OAc)2
dissolved. Dibromobenzene derivative (1equiv), aniline
derivative (2equiv) and sodium tert-butoxide (3equiv)
were then added, in that order, and the reaction mixture
heated for 14h at 110°C. The reaction mixture was cooled
to room temp and aqueous NH4Cl was added immediately
upon opening the reaction to air. The toluene layer was
separated and washed twice with water, dried over
MgSO4, filtered, and concentrated to an oil or a solid
under vacuum. The product was then recovered by
crystallization, the exact conditions of which depended
on the identity of the product. Generally, addition of a
small amount of methanol to the resulting oil or solid
resulted in formation of a powder that was filtered,
washed with cold methanol, and dried under vacuum to
yield a reasonably pure product (>95% by 1HNMR).
Isolated yields (%): 1a 90; 1b 87; 1c 60; 2a 37; 2b 75; 2c 56;
3a 55; 3b 62; 3c 56; 4a 67; 4b 35; 4c 73; 5a 32; 5b 30; 5c 25;
6 33; 7 92; 8 37; 9 73; 10b 26; 10c 9.
A thermal ellipsoid diagram of 11c is shown in Figure
1.ꢀ The crystal contains two independent molecules,
which are essentially equivalent except for slight differ-
ences in bond lengths and angles. The four N atoms
and the central ring are co-planar; the N(2)–C(2) and
N(1)–C(1) bond lengths are 1.339(4) and 1.312(4)A,
˚
respectively. The bond length of 1.498(4)A between
C(1) and C(2) is significantly longer than the C(2)–
C(3) and C(3)–C(1A) bond lengths of 1.378(4) and
˚
1.398(4)A. Thus the molecule may be described as com-
˚
posed of two equivalent, delocalized, 6-electron p sys-
tems, (the N(1)–C(1)–C(3A)–C(2A)–N(2A)unit and the
N(2)–C(2)–C(3)–C(1A)–N(1A)unit), which are not con-
jugated but are joined by C–C bonds.12,13
Acknowledgements
This work was supported by an award from Research
Corporation. X-ray diffraction was performed at the
Robert A. Welch Foundation funded Texas Center for
Crystallography at Rice University. We thank Robert
Michael Gower for help with syntheses.
7. Goodson, F. E.; Hauck, S. I.; Hartwig, J. F. J. Am. Chem.
Soc. 1999, 121, 7527–7539.
Supplementary data
8. Huang, J.; Nolan, S. P. J. Am. Chem. Soc. 1999, 121,
9889–9890.
9. Rumpel, H.; Limbach, H. H. J. Am. Chem. Soc. 1989, 111,
5429–5441.
Supplementary data associated with this article can be
10. Rumpel, H.; Limbach, H. H.; Zachmann, G. J. Phys.
Chem. 1989, 93, 1812–1818.
11. Siri, O.; Braunstein, B. Chem. Commun. 2000, 2223–2224.
12. Siri, O.; Braunstein, P.; Rohmer, M.-M.; Benard, M.;
Welter, R. J. Am. Chem. Soc. 2003, 125, 13793–13803.
13. Braunstein, P.; Siri, O.; Taquet, J.; Rohmer, M.-M.;
ꢀ Crystals of the azophenine 8cÆ0.5CH2Cl2 were grown from slow
evaporation of a methylene chloride solution. The crystals contained
two half molecules and CH2Cl2 in the unit cell. Crystal data for 11b:
˚
55H76Cl2, triclinic, P-1, a = 13.144(3)A, b = 13.519(3)A, c =
˚
´
Benard, M.; Welter, R. J. Am. Chem. Soc. 2003, 125,
12246–12256.
C
˚
15.861(3)A, a = 68.90(3)°, b = 81.97(3)°, c = 8.70(3)°.