1208
LETTERS
SYNLETT
phthalonitriles. Contrary to the Rosenmund-von Braun reaction,
formation of phthalocyanines as side products is avoided.
and triethylamine (23 mmol) in dichloromethane (10 ml). After
complete addition the mixture was allowed to warm to room
temperature and stirred overnight. Extractive workup and
chromatographic purification on silica gel using hexane-ethyl
acetate (2:1) gave the bistriflates in 72 to 89% yield.
Representative data for 2d: 1H-NMR (250 MHz, CDCl3) δ (ppm):
7.30 (m, 3H), 3.60 (s, 3H), 2.76 (t, 2H), 2.30 (t, 2H), 1.65 (m, 4H);
13C-NMR (62.9 MHz, CDCl3) δ (ppm): 173.5, 141.0, 138.8,
138.1, 130.3, 129.1, 120.7, 118.4 (q, JCF=314.5 Hz), 51.3, 33.3,
29.8, 28.9, 24.3; MS (EI) 489.0 (M++1); Anal. Calcd. for
References and Notes
(1) Lever, A. B. P.; Leznoff, C. C., Eds., Phthalocyanines, Properties
and Applications, Vol. 1-4, VCH Publishers, New York 1989-
1996.
(2) Ellis, G. P.; Romney-Alexander, T. M. Chem. Rev. 1987, 87, 779.
(3) Hanack, M.; Lang, M. Adv. Mater. 1994, 6, 819. Drechsler, U.;
Hanack, M. In Comprehensive Supramolecular Chemistry, Vol. 9;
Atwood, J. L.; Davies, J. E. D.; MacNicol, D. D.; Vögtle, F., Eds.;
Pergamon, 1996; p 283. Hanack, M.; Heckmann, H.; Polley, R. In
Houben-Weyl, 4th ed., Vol. E9d; Schaumann, E., Ed.; Thieme,
Stuttgart, 1997; p 717.
C14H14F6S2O8 (488.37): C, 34.43; H, 2.89; F, 23.34; S, 13.13;
Found: C, 34.66; H, 2.82; F, 24.04; S, 13.11.
(12) Typical Procedure for Phthalonitriles (3a-g). To a solution of
Pd2(dba)3 (0.4 mmol) and dppf (1.6 mmol) in DMF (20 ml) was
added at room temperature the aryl bistriflate 2a-g (10 mmol) in
DMF (5 ml) under a nitrogen atmosphere. After adjusting the final
reaction temperature (see Table 1), zinc(II) cyanide (in total
12 mmol) was added in 15 to 20 equal portions over a 2 h period.
Extractive workup and chromatographic purification on normal
grade silica gel using hexane-ethyl acetate (2:1) as eluent afforded
the corresponding phthalonitriles in 75 to 98% yield.
Representative data for 3d: 1H-NMR (250 MHz, CDCl3) δ (ppm):
7.60 (m, 3H), 3.64 (s, 3H), 2.89 (t, 2H), 2.34 (t, 2H), 1.68 (m, 4H);
13C-NMR (62.9 MHz, CDCl3) δ (ppm): 173.6, 148.2, 133.7,
132.9, 131.2, 116.4, 115.7, 115.6, 114.6, 51.6, 34.4, 33.5, 29.9,
24.3; MS (EI) 242.2 (M+); Anal. Calcd. for C14H14N2O2
(242.28): C, 69.41; H, 5.82; N, 11.56; Found: C, 69.73; H, 5.69;
N, 11.67.
(4) Stang, P. J.; Hanack, M.; Subramanian, L. R. Synthesis 1982, 85.
(5) Takagi, K.; Sakakibara, Y. Chem. Lett. 1989, 1957. Piers, E.;
Fleming, F. F. J. Chem. Soc., Chem. Commun. 1989, 756.
(6) Takagi, K.; Sasaki, K.; Sakakibara, Y. Bull. Chem. Soc. Jpn. 1991,
64, 1118.
(7) Negishi, E.; Okukado, N.; King, A. O.; Van Horn, D. E.; Spiegal,
B. I. J. Am. Chem. Soc. 1978, 100, 2254. Scott, W. J.; McMurry, J.
E. Acc. Chem. Res. 1988, 21, 47.
(8) Cabri, W.; Candiani, I.; DeBernadinis, S.; Francalanci, F.; Penco,
S.; Santi, R. J. Org. Chem. 1991, 56, 5796.
(9) Sakakibara, Y.; Okuda, F.; Shimobayashi, A.; Kirino, K.; Sakai,
M.; Uchino, N.; Takagi, K. Bull. Chem. Soc. Jpn. 1988, 61, 1985.
(10) Tschaen, D. M.; Desmond, R.; King, A. O.; Fortin, M. C.; Pipik,
(13) All other new compounds gave satisfactory elemental analysis and
the spectroscopic data are in good agreement with the proposed
structures.
B.; King, S.; Verhoeven, T. R. Synth. Commun. 1994, 24, 887.
(11) Typical Procedure for Aryl Bistriflates (2a-g). To a solution of
trifluoromethanesulfonic
anhydride
(23 mmol)
in
dry
(14) Chambers, M. R. I.; Widdowson, D. A. J. Chem. Soc., Perkin
Trans. I, 1989, 1365.
dichloromethane (15 ml) was added dropwise at -20°C under a
nitrogen atmosphere a solution of the catechol 1a-g (10 mmol)