M. J. McGlinchey et al.
FULL PAPER
9-[(p-Tolyl)ethynyl]-9H-fluorene (2b) and Spiro Compound 3b: To a
solution of 9-(p-tolyl)ethynyl-9H-fluoren-9-ol (1b) (300 mg,
1.01 mmol) in dry dichloromethane (10 mL), cooled to 0 °C, trieth-
ylsilane (242 µL, 1.51 mmol) was added slowly. Boron trifluoride-
etherate (124 µL, 1.01 mmol) was added dropwise. After stirring
for 15 min at 0 °C, the reaction was quenched with distilled water,
and the mixture was extracted with diethyl ether several times. The
organic layers were combined, washed with brine, dried with
MgSO4, filtered and concentrated to give a brown oil that was
chromatographed on silica gel using dichloromethane/pentane (1:9)
as eluent. Fluorene 2b was isolated as a pale yellow solid (186 mg,
0.66 mmol; 66%). A second product, identified as 3b, was also ob-
tained (39 mg, 0.1 mmol; 10%).
ane/ethyl acetate (90:9:1) as eluent. The cyclobutane derivative 8b
(297 mg, 0.53 mmol; 74%), m.p. 156–160 °C, was isolated as a
major product. A sample suitable for an X-ray diffraction struc-
tural determination was obtained by recrystallisation from diethyl
ether/pentane. NMR examination of the second fraction (100 mg,
0.18 mmol) indicated a 3:1 ratio of the red dimer 6b and the orange
dimer 7b. The mixture of 6b and 7b was triturated in acetonitrile
to give 7b (20 mg, 0.04 mmol; 5%) as a pure orange solid, m.p.
208–211 °C.
1
Data for 7b: H NMR (400 MHz, CDCl3): δ = 7.74 (d, 1 H, J =
7.6 Hz), 7.71 (d, 2 H, J = 7.6 Hz), 7.65 (d, 1 H, J = 8.0 Hz), 7.62
(d, 1 H, J = 7.6 Hz), 7.39 (d, 1 H, J = 7.6 Hz), 7.32–7.26 (m, 4 H),
7.24 (td, 2 H, J = 0.8 Hz, J = 7.6 Hz), 7.12 (td, 1 H, J = 0.8 Hz, J
= 7.6 Hz), 7.07 (td, 1 H, J = 1.2 Hz, J = 7.6 Hz), 7.05 (s, brd), 7.03
(td, 1 H, J = 1.2 Hz, J = 7.6 Hz), 6.90 (d, 1 H, J = 7.6 Hz), 6.85
(td, 1 H, J = 0.8 Hz, J = 7.6 Hz), 6.85 (s brd), 6.77 (td, 1 H, J =
1.2 Hz, J = 7.6 Hz), 6.27 (s, brd), 6.04 (s, brd), 5.32 (d, 1 H, J =
7.6 Hz), 5.23 (d, 1 H, J = 7.6 Hz), 2.18 (s, 3 H), 2.12 (s, 3 H). 13C
NMR (100 MHz, CDCl3): δ = 145.3, 141.0, 139.5, 139.2, 139.2,
139.1, 137.8, 136.6, 136.5, 135.3, 135.0, 135.0, 134.0, 133.2, 128.6,
128.3, 127.7, 127.6, 127.4, 126.9, 126.6, 126.6, 126.3, 126.1, 125.5,
125.4, 124.8, 124.5, 119.2, 118.7, 118.7, 118.6, 58.2, 56.4, 30.6, 22.1,
22.1, 2.4.
1
Data for 2b: H NMR (300 MHz, CDCl3): δ = 7.82 (d, 2 H, J =
7.0 Hz, 4-H, 5-H), 7.81 (d, 2 H, J = 7.0 Hz, 1-H, 8-H), 7.48 (t, 2
H, J = 7.5 Hz, 3-H, 6-H), 7.43 (t, 2 H, J = 7.5 Hz, 2-H, 7-H), 7.38
(d, 2 H, J = 8.5 Hz, phenyl o-H), 7.14 (d, 2 H, J = 8.0 Hz, phenyl
m-H), 5.08 (s, 1 H, 9-H), 2.38 (s, 3 H, CH3). 13C NMR (125 MHz,
CDCl3): δ = 144.4 (C-8a, C-9a), 140.5 (C-4a, C-4b), 138.1 (phenyl
p-C), 131.8 (phenyl o-C), 129.1 (phenyl m-C), 128.0 (C-3, C-6),
127.7 (C-2, C-7), 125.2 (C-1, C-8), 120.5 (phenyl ipso-C), 120.1 (C-
4, C-5), 86.4 (C-10), 82.3 (C-11), 40.0 (C-9), 21.5 (CH3). IR (liquid,
CH Cl ): ν = 2225 cm–1 (CϵC).
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2
2
1
Data for 3b: H NMR (500 MHz, CDCl3): δ = 7.79 (d, 2 H, J =
7.5 Hz, 4-H, 5-H), 7.35 (td, 2 H, J = 7.5 Hz, J = 1.0 Hz, 3-H, 6-
H), 7.32 (s, 1 H, 3Ј-H), 7.29 (d, 1 H, J = 7.5 Hz, 4Ј-H), 7.12 (td, 2
H, J = 7.5 Hz, J = 1.0 Hz, 2-H, 7-H), 7.03 (dd, 1 H, J = 7.5 Hz, J
= 1.0 Hz, 5Ј-H), 6.83 (d, 2 H, J = 7.5 Hz, 1-H, 8-H), 6.39 (d, 1 H,
J = 0.5 Hz, 7Ј-H), 2.15 (s, 3 H, phenyl-CH3), 0.65 (t, 9 H, J =
8.0 Hz, CH3), 0.08 (q, 6 H, J = 8.0 Hz, CH2). 13C NMR (125 MHz,
CDCl3): δ = 152.3 (C-7aЈ), 150.5 (C-2Ј), 146.5 (C-8a, C-9a), 143.9
(C-3Ј), 142.7 (C-3aЈ), 142.3 (C-4a, C-4b), 136.0 (C-6aЈ), 127.9 (C-
5Ј), 127.7 (C-3, C-6), 127.4 (C-2, C-7), 124.2 (C-1, C-8), 123.1 (C-
7Ј), 120.4 (C-4Ј), 120.1 (C-4, C-5), 72.2 (C-9), 21.5 (phenyl-CH3),
7.2 (CH3), 3.0 (CH2). C27H28Si (380.60): calcd. C 85.21, H 7.41;
found C 85.13, H 7.70.
1
Data for 8b: H NMR (500 MHz, CDCl3) numbering is in agree-
ment with the crystal structure: δ = 7.76 (d, 2 H, J = 7.0 Hz, 10-
H, 26-H), 7.75 (d, 2 H, J = 6.5 Hz, 13-H, 23-H), 7.55 (d, 2 H, J =
8.0 Hz, 7-H, 29-H), 7.39 (d, 4 H, J = 8.0 Hz, phenyl o-H), 7.34 (d,
2 H, J = 7.5 Hz, 16-H, 20-H), 7.33 (td, 2 H, J = 7.5 Hz, J = 1.0 Hz,
9-H, 27-H), 7.30 (td, 2 H, J = 8.0 Hz, J = 1.0 Hz, 14-H, 22-H),
7.14 (d, 4 H, J = 7.5 Hz, phenyl m-H), 7.09 (td, 2 H, J = 7.5 Hz,
J = 0.5 Hz, 15-H, 21-H), 7.04 (td, 2 H, J = 7.5 Hz, J = 1.0 Hz, 8-
H, 28-H), 4.77 (s, 2 H, 3-H, 4-H), 2.33 (s, 6 H, CH3). 13C NMR
(125 MHz, CDCl3): δ = 143.4 (C-1, C-2), 140.5 (C-12, C-24), 140.2
(C-11, C-25), 138.9 (C-31, C-37), 138.6 (C-17, C-19), 136.7 (C-6,
C-30), 136.7 (phenyl p-C), 134.5 (C-5, C-18), 130.0 (phenyl m-C),
128.6 (C-9, C-27), 128.3 (C-14, C-22), 128.2 (C-8, C-28), 127.5 (C-
15, C-21), 127.4 (phenyl o-C), 126.2 (C-7, C-29), 124.8 (C-16, C-
20), 120.0 (C-13, C-23), 119.5 (C-10, C-26), 62.2 (C-3, C-4), 21.2
(CH3). C42H28·0.5Et2O (569.74): calcd. C 92.76, H 5.84; found C
92.26, H 6.20.
1-(9H-Fluorenylidene)-4-(p-tolyl)-2-[(p-tolyl)methylene]spiro[cyclo-
butane-3,9Ј-[9H]fluorene] (5b): To 9-[(p-tolyl)ethynyl]-9H-fluorene
(2b) (1.06 g, 3.79 mmol) suspended in pentane (20 mL) and cooled
to 0 °C, was added triethylamine (11 µL, 0.08 mmol). The suspen-
sion was stirred overnight in a cold water bath. The precipitate was
filtered, washed with cold pentane and dried to give 5b (981 mg,
1.75 mmol; 92%) as an orange solid.
3,3-(Biphenyl-2,2Ј-diyl)-1-chloro-1-phenylallene (12): To a cooled
solution of 1a (300 mg, 1.06 mmol) in acetic acid (10 mL) was
added dropwise a 2 solution of hydrochloric acid (1.0 mL). Upon
stirring for 15 min with cooling, the precipitate was filtered and
washed with water. To the cooled filtrate was added dropwise a 2
solution of hydrochloric acid (1.0 mL). After stirring for 10 min,
the new precipitate was filtered, washed with water, combined with
the first one and dried to give 12 (267 mg, 0.89 mmol; 84%) as
a pale yellow powder. A sample suitable for an X-ray diffraction
structural determination was obtained by recrystallisation from di-
ethyl ether/pentane.
1
Data for 5b: H NMR (500 MHz, CDCl3): δ = 8.65 (d, 1 H, J =
8.00 Hz), 7.86 (d, 1 H, J = 8.0 Hz), 7.81 (d, 1 H, J = 7.5 Hz), 7.78
(d, 1 H, J = 7.5 Hz), 7.70 (d, 1 H, J = 7.5 Hz), 7.69 (d, 1 H, J =
7.0 Hz), 7.65 (s, 1 H), 7.43 (t, 1 H, J = 7.5 Hz), 7.40 (t, 1 H, J =
7.5 Hz), 7.36 (t, 1 H, J = 7.5 Hz), 7.27 (t, 1 H, J = 8.0 Hz), 7.26
(t, 1 H, J = 7.0 Hz), 7.22 (d, 1 H, J = 8.0 Hz), 7.12 (t, 1 H, J =
7.5 Hz), 7.00 (t, 1 H, J = 7.5 Hz), 6.90–6.80 (s, brd), 6.62 (d, 2 H,
J = 8.0 Hz), 6.58 (t, 1 H, J = 7.5 Hz), 6.45 (d, 2 H, J = 8.0 Hz),
6.42–6.30 (s, brd), 6.17 (d, 1 H, J = 7.5 Hz), 5.12 (s, 1 H), 2.24 (s,
3 H), 2.11 (s, 3 H). 13C NMR (125 MHz, CDCl3): δ = 150.2, 144.7,
143.3, 142.1, 141.4, 140.5, 139.8, 139.8, 138.5, 137.9, 137.6, 136.5,
134.9, 131.9, 131.0, 128.9, 128.2, 128.1, 128.0, 127.7, 127.6, 127.4,
127.2, 127.1, 126.7, 126.1, 125.3, 124.0, 122.9, 120.0, 119.8, 119.7,
119.3, 65.6, 61.6, 21.3, 21.2.
1
Data for 12: H NMR (500 MHz, CDCl3): δ = 7.75 (dt, 2 H, J =
7.0 Hz, J = 1.0 Hz, 4-H,5-H), 7.66 (dt, 2 H, J = 7.0 Hz, J = 1.5 Hz,
phenyl o-H), 7.63 (dt, 2 H, J = 7.5 Hz, J = 1.0 Hz, 1-H, 8-H), 7.42
(td, 2 H, J = 7.5 Hz, J = 1.5 Hz, 3-H, 6-H), 7.40–7.33 (m, 3 H,
phenyl m-H, p-H), 7.31 (td, 2 H, J = 7.5 Hz, J = 1.0 Hz, 2-H, 7-
H). 13C NMR (125 MHz, CDCl3): δ = 200.6 (C-10), 140.2 (C-4a,
C-4b), 136.4 (C-8a, C-9a), 133.0 (phenyl ipso-C), 129.6 (C-3, C-6),
129.1 (phenyl p-C), 128.8 (phenyl m-C), 127.7 (C-2, C-7), 126.8
(phenyl o-C), 124.3 (C-1, C-8), 120.5 (C-4, C-5), 114.3, 111.7 (C-9,
cis-1,2-Di(fluorenylidene)-3,4-di(p-tolyl)cyclobutane (7b) and trans-
1,2-Di(fluorenylidene)-3,4-di(p-tolyl)cyclobutane (8b): Spiro com-
pound 5b (400 mg, 0.71 mmol) was dissolved in toluene (8 mL) and
heated at reflux overnight. The solvent was removed and the resi-
due was purified on silica column using cyclohexane/dichlorometh-
C-11). IR (liquid, CHCl3):
ν
=
1936 cm–1 (C=C=C).
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2618
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Eur. J. Org. Chem. 2007, 2611–2622