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128.5, 151.2, 161.2 (o-, p-, m-F); 11B NMR ([D8]THF, 64.2 MHz):
d 19.0 (w1/2 260 Æ 20 Hz); IR (KBr): nÄ 3063, 1655, 1531 cm 1. The
reaction of 7 with 1 was also directly monitored by NMR spectroscopy. This
led to the detection of the product C6F5H and the intermediate 8. 8:
1H NMR ([D6]benzene, 599.8 MHz): d 6.83 (m, 2H, 6-H, 7-H), 6.64 (d,
3J 7.4 Hz, 1H, 8-H), 6.49 (s, 1H, 4-H), 6.35 (d, 3J 7.3 Hz, 1H, 5-H), 2.90
(s, 2H, 1-H); 13C NMR ([D6]benzene, 150.8 MHz): d 203.4 (C2), 155.0
(C3), 131.0 (C8a), 129.6 (C4a), 128.2 (C6, C7), 128.1 (C8), 127.1 (C5), 125.5
(C4), 29.9 (C1), B(C6F5)3 signals at 148.3 (1JCF 248 Hz), 146.0 (1JCF
248 Hz), 137.6 (1JCF 256 Hz) (o-, p-, m-CF), 113.7 (br, ipso-C of C6F5);
11B NMR ([D6]benzene, 64.2 MHz): d 14.4 (br, w1/2 260 Æ 20 Hz); 19F
NMR ([D6]benzene, 282.4 MHz): d 135.1, 154.4, 162.9 (o-, p-, m-F).
Received: May 25, 1999 [Z13458IE]
Publication delayed at authorsꢁ request
German version: Angew. Chem. 1999, 111, 3561 ± 3565
Keywords: boron
´ hydrozirconations ´ Lewis acids ´
naphthols ´ tautomerism
Scheme 1. Hydrozirconation of 3 and subsequent reactions.
[1] Reviews: H. Hart, Chem. Rev. 1979, 79, 515; B. Capon, B.-Z. Guo,
F. C. Kwok, A. K. Siddhanta, C. Zucco, Acc. Chem. Res. 1988, 21, 135;
selected recent examples: M. Kaftory, D. A. Nugiel, S. E. Biali, Z.
Rappoport, J. Am. Chem. Soc. 1989, 111, 8181; J. Frey, Z. Rappoport,
J. Am. Chem. Soc. 1996, 118, 3994; H. Koyama, T. Kawato, H.
Kanatomi, H. Matsushita, K. Yonetani, J. Chem. Soc. Chem.
Commun. 1994, 579; A. K. Cederstav, B. M. Novak, J. Am. Chem.
Soc. 1994, 116, 4073; P. E. Lindner, R. A. Correa, J. Gino, D. M.
Lemal, J. Am. Chem. Soc. 1996, 118, 2556; P. E. Lindner, D. M. Lemal,
J. Am. Chem. Soc. 1997, 119, 3259; Y. Chiang, A. J. Kresge, Science
1991, 253, 395; J. Andraos, Y. Chiang, A. J. Kresge, V. V. Popik, J. Am.
Chem. Soc. 1997, 119, 8417; Y. Chiang, A. J. Kresge, V. V. Popik, N. P.
Schepp, J. Am. Chem. Soc. 1997, 119, 10203, and references therein.
[2] a) A. J. Birch, K. B. Chamberlain, M. A. Haas, D. J. Thompson, J.
Chem. Soc. Perkin Trans. 1 1973, 1882; K. H. Dötz, Angew. Chem.
1984, 96, 573; Angew. Chem. Int. Ed. Engl. 1984, 23, 587; C. A. Merlic,
D. Xu, J. Am. Chem. Soc. 1991, 113, 7418; M. E. Kopach, W. D.
Harman, J. Am. Chem. Soc. 1994, 116, 6581; W. D. Wulff, B. M. Bax,
T. A. Brandvold, K. S. Chan, A. M. Gilbert, R. P. Hsung, J. Mitchell, J.
Clardy, Organometallics 1994, 13, 102; J. Le Bras, H. Amouri, J.
Vaissermann, J. Organomet. Chem. 1998, 567, 57; J. Le Bras, M. N.
Rager, Y. Besace, H. Amouri, J. Vaissermann, Organometallics 1997,
16, 1765; M. E. Kopach, W. G. Hipple, W. D. Harman, J. Am. Chem.
Soc. 1992, 114, 1736; M. E. Kopach, W. D. Harman, J. Am. Chem. Soc.
1994, 116, 6581; b) for other ways to achieve the hydroxyarene keto
tautomer formation see, for example, H. Baba, T. Takemura, Bull.
Chem. Soc. Jpn. 1964, 37, 1241; C. A. Grob, B. Hofer, Helv. Chim. Acta
1952, 35, 2095; J. F. Grove, J. Chem. Soc. C 1966, 985; additional
examples: ref. [1a] and M. Kimura, S. Morosawa, J. Am. Chem. Soc.
1981, 103, 2433; c) for indications of keto tautomer involvement in
Friedel ± Crafts chemistry of phenols and naphthols see, for example,
V. G. Koptyug, T. P. Andreeva, V. I. Mamatyuk, Zh. Org. Khim. 1970,
6, 1848 (Engl. Transl. 1970, 6, 1859); K. Yu. Koltunov, E. N. Subbotina,
I. B. Repinskaya, Zh. Org. Khim. 1997, 33, 750 (Engl. Transl. 1997, 33,
689); K. Yu. Koltunov, M. M. Shakirov, I. B. Repinskaya, Zh. Org.
Khim. 1998, 34, 630 (Engl. Transl. 1998, 34, 595), and references
therein.
vacuo to yield 3 (1.17 g, 89%) as a slightly green solid, m.p. 1348C.
Elemental analysis (%) calcd for C28H8OBF15 (656.15): C 51.25, H 1.23;
found: C 51.16, H 1.59. Diffusion of pentane vapor into a solution of 3 in
toluene at 408C over 3 d furnished single crystals that were suitable for
X-ray crystal structure analysis.[5a] IR (KBr): nÄ 3587, 1646, 1621 cm 1. The
NMR spectra showed the presence of an equilibrium mixture (2 1 > 3;
25:75) in solution. 3: 1H NMR ([D6]benzene, 599.8 MHz): d 8.43 (d, 3J
8.1 Hz, 1H, 8-H), 6.94 (m, 1H, 6-H), 6.87 (m, 1H, 7-H), 6.78 (d, 3J
3
10.0 Hz, 1H, 2-H), 6.40 (d, J 7.8 Hz, 1H, 5-H), 6.26 (m, 1H, 3-H), 2.31
(br., 2H, 4-H); 13C NMR ([D6]benzene, 150.8 MHz): d 189.9 (C1), 162.4
(C3), 145.4 (C4a), 136.0 (C6), ꢀ129 (C7, C8a), 128.3 (C5), 123.3 (C2), 33.7
(C4), B(C6F5)3 signals at 148.4 (1JCF 247 Hz), 140.7 (1JCF 256 Hz), 137.7
(1JCF 254 Hz) (o-, p-, m-CF); 11B NMR ([D6]benzene, 64.2 MHz): d 0.1
(w1/2 380 Æ 20 Hz); 19F NMR ([D6]benzene, 282.4 MHz): d 128.7,
151.8, 158.6 (o-, p-, m-F).
5 and 6: The reaction of 4 (100 mg, 625mmol) with B(C6F5)3 (320 mg,
625mmol) in pentane (20 mL) was carried out analogously to that of 1 and 2
to yield 5 (400 mg, 95%) as an off-white solid, m.p. 788C. Elemental
analysis (%) calcd for C28H8O2BF15 (672.16): C 50.03, H 1.20; found: C
49.61, H 1.98; IR (KBr): nÄ 3563, 1646, 1609 cm 1. Single crystals were
obtained from toluene/pentane by the diffusion method.[5b] In solution the
NMR signals of a 70:30 mixture of the regioisomers 5 (major product) and 6
(minor product) were observed. 5: 1H NMR ([D6]benzene, 599.8 MHz):
d 8.37 (d, 3J 7.5 Hz, 1H, 8-H), 6.90 (m, 1H, 6-H), 6.88 (m, 1H, 7-H), 6.19
3
(d, J 7.2 Hz, 1H, 5-H), 5.88 (s, 1H, 2-H), 4.98 (s, 1H, OH), 2.18 (s, 2H,
4-H); 13C NMR ([D6]benzene, 150.8 MHz): d 189.4 (C1), 185.9 (C3),
137.8 (C4a), 134.7 (C6), 128.7 (C7), 128.1 (C8), ꢀ128 (C5, C8a), 102.6 (C2),
33.6 (C4), B(C6F5)3 signals at 148.5 (1JCF 241 Hz), 140.5 (1JCF 246 Hz),
137.7 (1JCF 248 Hz), 118.8 (br) (o-, p-, m-, ipso-C of C6F5); 19F NMR
([D6]benzene, 282.4 MHz): d 133.6, 157.0, 163.8 (o-, p-, m-F); 11B
NMR ([D6]benzene, 64.2 MHz): d 0.6 (w1/2 400 Æ 20 Hz). 6: 1H NMR
([D6]benzene, 599.8 MHz); d 7.21 (d, 3J 8.1 Hz, 1H, 8-H), 6.81 (m, 1H,
3
6-H), 6.68 (m, 1H, 7-H), 6.31 (d, J 8.0 Hz, 1H, 5-H), 5.52 (s, 1H, 2-H),
5.36 (s, 1H, OH), 3.31 (s, 2H, 4-H); 13C NMR ([D6]benzene, 150.8 MHz):
d 199.6 (C3), 179.5 (C1), 139.1 (C4a), 134.2 (C6), 128.1 (C5), 127.9 (C7),
125.8 (C8), 123.6 (C8a), 101.7 (C2), 39.6 (C4); B(C6F5)3 signals are
undistinguishable from those of 5.
[3] For examples of h6-phenol complexes, see C. White, S. J. Thompson,
P. M. Maitlis, J. Organomet. Chem. 1977, 127, 415.
9: A mixture of 7 (160 mg, 1.00 mmol) and 1 (512 mg, 1.00 mmol) was
dissolved in toluene (15 mL) at 08C. The solution was warmed to room
temperature and then allowed to stand at that temperature for 2 d. The
supernatant solution was decanted from the precipitated green product.
The solid was washed with pentane (5 mL) and dried in vacuo to give 9
(104 mg, 31%), m.p. 2618C. Elemental analysis (%) calcd for C16H6O2BF5
(336.02): C 57.19, H 1.80; found: C 56.93, H 2.04. Single crystals of 9 were
obtained from a solution in benzene after 2 d at room temperature.[5c]
1H NMR ([D8]THF, 599.8 MHz): d 7.69 (dd, 3J 6.2 Hz, 4J 3.3 Hz, 2H,
6-H, 7-H), 7.34 (s, 2H, 1-H, 4-H), 7.26 (dd, 3J 6.2 Hz, 4J 3.3 Hz, 2H, 5-H,
6-H); 13C NMR ([D8]THF, 150.8 MHz): d 150.8 (C2, C3), 131.5 (C4a,
C8a), 127.8 (C6, C7), 124.4 (C5, C8), 106.9 (C1, C4), B(C6F5)3 signals at
150.0 (1JCF 252 Hz), 142.8 (1JCF 255 Hz), 138.3 (1JCF 252 Hz) (o-, p-, m-
C of C6F5; ipso-C not observed); 19F NMR ([D8]THF, 282.4 MHz): d
[4] A. G. Massey, A. J. Park, F. G. A. Stone, Proceedings Chem. Soc. 1963,
212; A. G. Massey, A. J. Park, J. Organomet. Chem. 1964, 2, 245; A. G.
Massey, A. J. Park in Organometallic Synthesis, Vol. 3 (Eds.: R. B.
King, J. J. Eisch), Elsevier, New York, 1986, p. 461.
[5] a) X-ray crystal structure analysis of 3:[5d] C28H8OBF15, Mr 656.15,
colorless crystal, 0.40 Â 0.30 Â 0.30 mm, a 12.560(1), b 10.444(1),
3
c 19.857(1) , b 102.88(1)8, V 2539.2(3) 3, 1calcd 1.716 g cm
,
F(000) 1296 e, m 16.29 cm 1, absorption correction with y scan
data (0.562 ꢁ Tꢁ 0.641), Z 4, monoclinic, space group P21/n
(no. 14), l 1.54178 , T 223 K, w/2q scans; of 4533 reflections
collected ( h, k, Æl), [(sinq)/l]max 0.55 1, 4319 were independ-
ent and 3787 observed [I ꢂ 2s(I)]; 407 refined parameters, R 0.065,
3
wR2 0.176, max./min. residual electron density 0.49/ 0.47 e
;
3364
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Angew. Chem. Int. Ed. 1999, 38, No. 22