8800
A. A. Kiryano6 et al. / Tetrahedron Letters 42 (2001) 8797–8800
Hornung, B.; Schmidt, W.; Winger, R. DE 19907063,
2000; (b) Wingen, R.; Hornung, B.; Schmidt, W. DE
19941653, 2001.
11. Corral, C.; Lasso, A.; Lissavetzky, J.; Alvarez-Insua, A.
S.; Valdeolmillos, A. M. Heterocycles 1985, 23, 1431–
1435.
3. (a) Lagerwall, S. T. Ferroelectric and Antiferroelectric
Liquid Crystals; Wiley-VCH: Weinheim, 1999; (b) Mills,
J. T.; Gleeson, H. F.; Seed, A.; Hird, M.; Styring, P. Mol.
Cryst. Liq. Cryst. 1997, 303, 145–152; (c) Mills, J. T.;
Gleeson, H. F.; Goodby, J. W.; Hird, M.; Seed, A.;
Styring, P. J. Mater. Chem. 1998, 8, 2385–2390.
12. (a) Pearson, D. E.; Pope, H. W.; Hargrove, W. W.;
Stamper, W. E. J. Org. Chem. 1958, 23, 1412–1419; (b)
Conde, S.; Madronero, R.; Fernandez-Tome, M. P.; del
Rio, J. J. Med. Chem. 1978, 21, 978–981; (c) Iriarte, J.;
Martinez, E.; Muchowski, J. M. J. Heterocyclic Chem.
1976, 13, 393–394.
4. (a) Fu¨nfschilling, J.; Schadt, M. Ferroelectrics 1998, 213,
195–208; (b) Seed, A. J.; Toyne, K. J.; Goodby, J. W. J.
Mater. Chem. 1995, 5, 653–661.
13. Fu, M.; Nikolic, D.; Van Breemen, R. B.; Silverman, R.
B. J. Am. Chem. Soc. 1999, 121, 7751–7759.
14. 1H, 13C and 19F NMR data for new fluorothiophene
building blocks 9, 10, 15 and 22 are presented below.
5. This work was presented at the 222nd ACS National
Meeting, August 26–30, 2001, Chicago, IL (P-152).
6. MHDDOPTCOB is a non-fluorinated analog of 1 and 3.
See: Lagerwall, S. T. In Ferroelectric and Antiferroelectric
Liquid Crystals; Wiley-VCH: Weinheim, 1999; p. 370.
7. A convenient but low yielding (30–32%) approach to
3-fluorothiophenes involving Balz–Schiemann fluorina-
tion has recently been reported. See: (a) Kobarfard, F.;
Kaufmann, J. M.; Boyko, W. J. J. Heterocyclic Chem.
1999, 36, 1247–1251. While other approaches to 3- and
4-fluorothiophenes have been developed recently, limita-
tions such as moderate to low yields, lengthy precursor
preparation, limited flexibility and/or the use of expensive
fluorinating agents, restrict their attractiveness for materi-
als synthesis. See: (b) El Kassmi, A.; Fache, F.; Lemaire,
M. Synth. Commun. 1994, 24, 95–101; (c) Taylor, E. C.;
Ping, Z. Org. Prep. Proced. Int. 1997, 29, 221–223; (d)
Sakamoto, Y.; Komatsu, S.; Suzuki, T. J. Am. Chem.
Soc. 2001, 123, 4643–4644; (e) Andres, D. F.; Laurent, E.
G.; Marquet, B. S. Tetrahedron Lett. 1997, 38, 1049–
1052.
1
Compound 9: H NMR l 3.91 (s, 3H), 7.42 (d, JHꢀF=3.9
Hz, 1H); 13C NMR l 52.5, 101.9 (d, JCꢀF=26.2 Hz),
113.2 (d, JCꢀF=10.2 Hz), 127.3 (d, JCꢀF=3.2 Hz), 156.4
(d, JCꢀF=276.9 Hz), 160.1 (d, JCꢀF=4.5 Hz); 19F NMR l
−112.3 (d, J=3.5 Hz, 1F). Compound 10: 1H NMR l
3.89 (s, 3H), 7.42 (d, JHꢀF=1.2 Hz, 1H); 13C NMR l
52.8, 100.3 (d, JCꢀF=24.8 Hz), 122.2 (d, JCꢀF=24.8 Hz),
131.2 (d, JCꢀF=7.0 Hz), 155.7 (d, JCꢀF=263.9 Hz), 161.2
(d, JCꢀF=2.5 Hz); 19F NMR l −124.3 (d, J=1.2 Hz, 1F).
Compound 15: 1H NMR l 3.91 (s, 3H); 13C NMR l
52.7, 106.6 (d, JCꢀF=26.3 Hz), 113.8 (d, JCꢀF=9.8 Hz),
117.9 (d, JCꢀF=4.6 Hz), 155.3 (d, JCꢀF=279.9 Hz), 159.4
(d, JCꢀF=3.8 Hz); 19F NMR l −105.6 (s, 1F). Compound
22: 1H NMR l 3.89 (s, 3H), 6.96 (dd, J=1.8, 0.8 Hz,
1H), 7.50 (dd, J=1.8, 0.9 Hz, 1H); 13C NMR l 52.5,
110.9 (d, JCꢀF=20.3 Hz), 122.5 (d, JCꢀF=25.4 Hz), 132.0
(d, JCꢀF=7.6 Hz), 157.4 (d, JCꢀF=260.0 Hz), 161.9 (d,
J
CꢀF=2.5 Hz); 19F NMR l −126.3 (app t, JFꢀH=0.7 Hz,
3
1F) (it should be noted that JHꢀF is very small between
vicinal H and F substituents at the C(3) and C(4) posi-
tions on the thiophene ring).
8. Robinson, W. K.; Gleeson, H. F.; Hird, M.; Seed, A. J.;
Styring, P. Ferroelectrics 1996, 178, 249–266.
9. Miyaura, N.; Suzuki, A. Chem. Rev. 1995, 95, 2457–2483.
10. Matharu, A. S.; Grover, C.; Komitov, L.; Andersson, G.
J. Mater. Chem. 2000, 10, 1303–1310.
15. Hassner, A.; Alexanian, V. Tetrahedron Lett. 1978, 19,
4475–4478.
16. The lower yield for 1 was due to the extensive purification
required to obtain highly pure material.