5632 J . Org. Chem., Vol. 64, No. 15, 1999
Dell et al.
calcd for C30H27O6PS3 610.0707. Single crystals, suitable for
X-ray analysis, were obtained from DMSO-MeOH.
tracted twice with hot chloroform. The extracts were combined,
the solvent was evaporated, and the residue was chromato-
graphed on silica gel (solvent, 4:1 toluene-hexanes) to yield a
pale yellow oil. Further purification by preparative TLC
(solvent, 1:1 toluene-hexanes) gave a colorless oil (29 mg).
This material exhibited a single component by TLC (solvent,
benzene; Rf 0.37), the mass spectrum showed the correct
molecular ion for 2, but the 1H NMR spectrum clearly indicated
that a mixture was present. This could not be further fraction-
ated by chromatography, but direct crystallization from CHCl3-
EtOH yielded 6 mg of 2 (0.011 mmol, 0.4%) as crystals suitable
for spectroscopic and crystallographic analysis. 1H NMR (CD2-
Cl2) δ 3.71 (s, 6 H), 3.77 (s, 6 H), 7.14 (m, 6 H), 7.16 (s, 3 H),
7.36 (m, 6 H); 19F NMR (CD2Cl2) δ -155.3; MS, m/z 530 (M+,
19), 178 (100); exact mass 530.1018, calcd for C30H27FS3Si
530.1028.
P h osp h a p h a n e 11. 1,3,5-Tris(mercaptoethyl)benzene9 (21,
0.19 g, 0.71 mmol) and compound 16 (0.29 g, 0.71 mmol) were
mixed in 2:1 benzene-ethanol (750 mL), and the solution was
heated to reflux. An argon-saturated solution of KOH (0.19 g,
3.4 mmol) in ethanol (45 mL) was added over 2.5 h. After 39
h, the solution was cooled, and the solvent was evaporated
under reduced pressure to leave a white residue. The residue
was extracted twice with hot chloroform. The combined
extracts were concentrated, and the resulting yellow oil was
chromatographed on silica gel (solvent, 1:1 hexanes-toluene)
to yield 11 as a white solid (201 mg, 0.36 mmol, 51%); mp 226-
1
229 °C. H NMR (CDCl3) δ 2.88 [overlapping t (6 H) and t (6
H)], 3.66 (s, 6 H), 6.55 (dd, J ) 7, 3, 3 H), 7.02 (dd, J ) 7, 7 Hz
3 H), 7.23 (s, 3 H), 7.26 (dd, J ) 7, 7 Hz, 3 H), 7.54 (dd, J ) 7,
7 Hz, 3 H); 13C NMR (CDCl3) δ 33.4, 36.07 (J PC ) 28 Hz), 36.63,
127.3 (J PC ) 10 Hz), 128.1 (J PC ) 14 Hz), 129.2, 129.3, 133.6,
135.6 (J PC ) 16 Hz), 140.6, 142.1 (J PC ) 26 Hz); MS, m/ z 556
(M+, 100); exact mass 556.1494, calcd for C33H33PS3 556.1482.
P h osp h a p h a n e Tr isu lfon e 18. m-Chloroperbenzoic acid
(50-60% by wt) was purified as follows: it was dissolved in
CH2Cl2, washed with phosphate buffer (10 mL) at pH 7.5, dried
over Na2SO4 and concentrated to dryness. To an ice-chilled,
stirred solution of cyclophane 11 (36.9 mg, 0.066 mmol) in CH2-
Cl2 (10 mL), a solution of m-CPBA in CH2Cl2 (10 mL) was
added dropwise. The ice bath was removed, and the reaction
stirred for 1 day under argon. The CH2Cl2 mixture was washed
with a solution of sodium thiosulfate followed by saturated Na2-
CO3, and it was dried over Na2SO4. The solvent was evaporated
to give 18 as a beige solid (42.7 mg, 0.065 mmol, 99%); mp
Tr i(o-tolyl)(m eth yl)sila n e (25). Tri(o-tolyl)silane11 (0.670
g, 2.2 mmol), methyllithium (3.1 mL, 1.4 M in hexanes, 4.4
mmol), and THF (15 mL) were heated to reflux overnight
under argon. The reaction mixture was cooled in an ice bath,
and 1 M HCl was added to quench the reaction. Ether was
added, the layers were separated, and the aqueous layer was
extracted with ether. The combined organics were dried over
Na2SO4 and concentrated under reduced pressure to leave a
reddish-brown semisolid. Chromatography on silica gel (sol-
vent, hexanes) gave compound 25 as a colorless oil that
solidified upon drying under vacuum (0.627 g, 1.98 mmol,
1
89%); mp 83-84 °C [lit.17 87-88 °C]. H NMR (CDCl3) δ 0.99
(s, 3 H), 2.28 (s, 9 H), 7.12 (dd, J ) 7, 7 Hz, 3 H), 7.23 (m 6 H),
7.34 (ddd, J ) 7, 7, 1 Hz, 3 H).
Tr is[o-(br om om eth yl)p h en yl](m eth yl)sila n e (26). A so-
lution of compound 25 (0.61 g, 1.9 mmol) and NBS (1.10 g, 6.3
mmol) in CCl4 (15 mL) was illuminated with a tungsten lamp
for 1 day. After the solution cooled, the succinimide was filtered
off, and the filtrate was concentrated to leave a yellow oil.
Chromatography on silica gel (solvent, 16:1 hexanes-toluene)
gave 26 as a white semisolid (685 mg, 1.3 mmol, 65%). 1H NMR
(CDCl3) δ 1.23 (s, 3 H), 4.39 (s, 6 H), 7.24 (d, J ) 4 Hz, 6 H),
7.4 (m, 3H), 7.59 (d, J ) 8 Hz, 3 H); 13C NMR (CDCl3) δ 1.5,
34.7, 128.3, 131.1, 132.1, 134.6, 136.7, 144.3; MS m/z 537 (M+
[79Br281Br], 6), 457 (M - HBr, 23), 179 (100).
1
>400 °C. H NMR (CDCl3) δ 3.22 (t, J ) 5 Hz, 6 H), 3.57 (t, J
) 5 Hz, 6 H), 4.29 (s, 6 H), 6.55 (ddd, J ) 7, 4, 1 Hz, 3 H), 7.15
(s, 3 H), 7.21 (dd, J ) 7, 7 Hz, 3 H), 7.38 (dd, J ) 7, 7 Hz, 3 H),
7.61 (dd, J ) 7, 7 Hz, 3 H); MS, m/z 652 (M+, 100); exact mass
652.1190, calcd for C33H33O6PS3 652.1177. Single crystals,
suitable for X-ray analysis, were obtained from CH2Cl2-
MeOH.
Tr i(o-tolyl)flu or osila n e (23). Tri(o-tolyl)silane11 (22, 4.11
g, 13.6 mmol), silver fluoride (5.15 g, 40.6 mmol), and THF
(100 mL) were heated at reflux for 4 days under argon. After
cooling, the reaction mixture was filtered through neutral
alumina, and concentration of the filtrate yielded a yellow-
green oil. Chromatography on silica gel (solvent, hexanes) gave
23 as a colorless oil which solidified upon drying under vacuum
(3.04 g, 9.50 mmol, 70%); mp 83-84 °C. Crystals from the solid
mass proved suitable for X-ray analysis. 1H NMR (CDCl3) δ
2.36 (d, J HF ) 2 Hz, 9 H), 7.12 (dd, J ) 7, 7 Hz, 3 H), 7.24 (m,
6 H), 7.36 (ddd, J ) 7, 7, 1 Hz, 3 H); 13C NMR (CDCl3) δ 23.2
(d, J FC ) 2 Hz), 125.3, 130.3, 131.1, 132.2, (d, J FC ) 16 Hz),
136.3, (d, J FC ) 4 Hz), 145.0; 19F NMR (CD2Cl2, CFCl3
reference) δ -160.6; MS, m/z 320 (M+, 17), 228 (M - C7H8,
100), 213 (M - C7H8 - CH3, 57); exact mass 320.1391, calcd
for C21H21FSi, 320.1397.
Tr is[2-(br om om eth yl)p h en yl]flu or osila n e (24). A solu-
tion of compound 23 (2.9 g, 9.1 mmol) and NBS (5.32 g, 29.9
mmol) in CCl4 (50 mL) at reflux was illuminated with a
tungsten lamp for 2 days. After the mixture cooled, the
succinimide was filtered away, and the filtrate was concen-
trated to leave a yellow oil. The oil was chromatographed on
silica gel (solvent, 12:1 hexanes-toluene) to give 24 as a white
solid (1.73 g, 3.1 mmol, 34%); mp 127-129 °C. 1H NMR (CDCl3)
δ 4.54 (s, 6 H), 7.27 (dd, J ) 7, 7 Hz, 3 H), 7.33 (dd, J ) 7, 1.5
Hz, 3 H), 7.51 (ddd, J ) 7, 7, 1.5 Hz, 3 H), 7.58 (d, J ) 7 Hz,
3 H); 13C NMR (CDCl3) δ 33.7 (d, J FC ) 3 Hz), 128.0, 131.2 (d,
J FC ) 15 Hz), 131.7, 132.3, 136.9 (d, J FC ) 3 Hz), 144.4; MS,
m/z 556 (M+ [79Br281Br], 2), 477 (M - Br, 47), 178 (100); exact
mass 557.8682, calcd for C21H18F79Br81Br2Si 557.8671.
F lu or osila p h a n e 2. A solution of 1,3,5-tris(mercaptometh-
yl)benzene (20, 0.625 g, 2.89 mmol) and compound 24 (1.61 g,
2.89 mmol) in 2:1 benzene-ethanol (1.5 L) was heated to
reflux. An argon-saturated solution of KOH (0.535 g, 9.54
mmol) in ethanol (100 mL) was added over 8 h. After 12 h of
heating, the solution was cooled, and the solvent was evapo-
rated to leave a white precipitate. The precipitate was ex-
Meth ylsila p h a n e 15. Compounds 21 (0.27 g, 1.1 mmol) and
26 (0.58 g, 1.1 mmol) were mixed in 2:1 benzene-ethanol
(1.125 L), and the solution was heated to reflux. An argon-
saturated solution of KOH (0.28 g, 5.0 mmol) in ethanol (75)
mL was added over 6 h. After 21 h, the solution was cooled,
and the solvent was evaporated under reduced pressure to
leave a white precipitate. The precipitate was extracted twice
with hot chloroform. The combined extracts were concentrated,
and the resulting mixture was chromatographed on silica gel
(solvent, toluene) to yield a pale yellow solid. A compound
exhibiting Rf ) 0.38 on silica gel TLC (solvent, 5:1 toluene-
hexanes) was isolated, and it was further purified by prepara-
tive TLC (solvent, 5:1 toluene-hexanes) to give cyclophane 15
1
as a white solid (131 mg, 0.23 mmol, 22%); mp 193° (dec). H
NMR (300 MHz, CDCl3) δ 0.73 (s, 3 H), 2.43 (m, 3 H), 2.85 (m,
9 H), 2.98 (d, J ) 14 Hz, 3 H), 3.30 (d, J ) 14 Hz, 3 H), 6.92
(s, 3 H), 7.20 (ddd, J ) 7, 7, 1.5 Hz, 3 H), 7.33 (m, 6 H), 7.53
(d, 7 Hz, 3 H); 13C NMR (67.9 MHz, CDCl3) δ 4.9 (Si-CH3),
35.2, 37.3, 38.4, 126.4, 128.2, 129.0, 129.7, 136.1, 136.6, 140.9,
145.0; MS, m/z 568 (M+, 19), 149 (100); exact mass 568.1754,
calcd for C34H36S3Si 568.1749. Single crystals, suitable for
X-ray analysis, were obtained from CHCl3-MeOH.
Gen er a l X-r a y Cr ysta llogr a p h ic P r oced u r es. X-ray data
were collected by using graphite monochromated Mo KR
radiation (0.710 73 Å) on either a Siemens P4 diffractometer
(compounds 15, 17, and 18) or a Nonius KappaCCD diffrac-
tometer (compounds 2 and 23). Processing of the diffraction
data was accomplished by using Siemens XSCANS22 for the
former structures, and by using DENZO-SMN23 for the latter.
(22) XSCANS, Release 2.10b; Siemens Analytical X-ray Instru-
ments: Madison, WI, 1994.
(23) Otwinowski, Z.; Minor, W. Methods Enzymol. 1997, 276, 307-
326.