4
Tetrahedron
by intramolecular nucleophilic substitution in the cyclization.
Trichloroisocyanuric acid (0.82 g, 4.4 mmol) was dissolved in 7
mL of dry DMF. Alcohol 3 (0.30 g, 0.44 mmol) was added and
the reaction was stirred overnight. Water (100 mL) and ether
(100 mL) were added. The organic phase thus separated was
dried (MgSO4) and evaporated. The obtained residue was
dissolved in CH2Cl2 and passed through a short silica gel column.
The solvent was evaporated and the residue was washed with
hexane several times. A pale yellow sticky substance (0.16 g,
Even under mild conditions, small amounts of 2,11,20-
trithia[33](1,3,5)cyclophane were isolated as a byproduct. By
crystallographic analysis, the structure of 1 in the solid state was
not symmetrical but in a collapsed shape. However, in solution,
the 1H and 13C NMR spectra showed two or three sharp singlets,
respectively, which suggest its symmetrical cage structure. Thus,
the inclusion space is satisfyingly retained. Attempted inclusion
experiments with various cations were not well achieved because
there was little of the obtained sample 1 and adequate solvents
that dissolved both 1 and metal salts could not be found.
Ga(GaBr4) was soluble in C6D6 and inclusion was expected, but a
determinative result was not obtained in this case. Further studies
to obtain complex crystals of Ga+ 1 are now in progress.
1
45.7%) was obtained. H NMR (CDCl3, 300.4 MHz): δ 3.55 (s,
6H, CH2), 3.56 (s, 6H, CH2), 4.54 (s, 12H, CH2), 7.15-7.36 (m,
12H, ArH). 13C NMR (CDCl3, 75.6 MHz): δ 35.1, 45.6, 53.4,
127.3, 128.2, 129.1, 138.2. MALDI-TOF MS: No parent peak
was detected.
Melting point and Spectroscopic data of 5
o
Mp. > 310 C (dec.). 1H NMR (CDCl3, 300.4 MHz): δ 3.84 (s,
12H, CH2), 6.89 (s, 6H, ArH). 13C NMR (CDCl3, 75.6 MHz): δ
38.5, 130.2, 137.0.
4. EXPERIMENTAL SECTION
Synthesis of cage compound C36H36S6 1
General Procedure
In a 500 mL three-necked flask, hexachloride 4 (0.15 g, 0.19
mmol) was dissolved in a mixture of 200 mL of CH3CN and 50
mL of CH2Cl2. With stirring, an ethanol solution (100 mL) of
Na2S·9H2O (0.18 g, 0.77 mmol) was added dropwise and the
reaction was stirred at room temperature for 3 days. The solid
material was removed by suction filtration and the solution was
evaporated. The mixture thus obtained was separated by
preparative TLC and pale yellow crystals were isolated (0.010 g,
Melting points were obtained on a Yanaco MP-500D apparatus
in Ar sealed tubes, and are uncorrected. NMR spectra were
collected on a JEOL AL-300 spectrometer (300.4 MHz for H,
1
75.6 MHz for 13C) with TMS or solvents as internal references.
FAB MS data were collected on a JEOL JMS-SX/SX102A.
MALDI-TOF MS data were collected on a Bruker Daltonics,
autoflex speed TOF/TOF. Chromatography was performed on a
medium-pressure liquid chromatography system, YAMAZEN
YFLC-254-GRII. Silica gel PTLC was performed with PF256
(Aldrich). Liquid-phase separation filter paper was purchased
from ADVANTEC Co., Ltd.
1
8.3%). Mp. > 313 °C (dec). H NMR (CDCl3, 300.4 MHz): δ
3.49 (s, 24H, CH2), 6.83 (s, 12H, ArH), 13C NMR (CDCl3, 75.6
MHz): δ 36.0, 127.7, 138.1. HRMS (addition of CF3SO3Ag):
calcd for C36H36S6Ag+ 767.0192; found 767.0203.
Synthesis of hexaester 2
In dry THF (100 mL), tris(mercaptomethyl)benzene (2.51 g,
0.011 mol) and Cs2CO3 (11.35 g, 0.034 mol) were added and the
mixture was stirred for
(bromomethyl)isophthalic acid diethyl ester (11.0 g, 0.034 mol)
was added and the reaction was heated under reflux overnight.
Water (100 mL) and CH2Cl2 (100 mL) were added and the
organic phase was separated using liquid-phase separation filter
paper. Organic solvents were evaporated and a pale yellow sticky
Crystallographic analysis data of compound 1:
C37H37Cl3S6, Mr = 780.38 g mo1-1, prisms (grown from CHCl3),
size 0.19 0.17 0.15 mm, monoclinic, space group P21/n, a =
8.8903 (10) Å, b = 16.3097 (19) Å, c = 24.855 (3) Å, =
90.1394(18)°, V =3604.0 (7) Å3, Z = 4, calcd. = 1.438 gcm-3,
(Mo K) = 0.630 mm-1, F(000) = 1624, T = 123(2) K using the
-2 scan technique to a maximum 2 value of 55.0°. A total of
28248 reflections were collected. The final cycle of the full-
matrix least-squares refinement was based on 8195 observed
reflections (I > 2 (I)) and 581 variable parameters and
converged with unweighted and weighted agreement factors of R
= 0.0428, Rw = 0.1072 and GOF = 1.029. The maximum and
minimum peaks on the final difference Fourier map corresponded
to 1.045 and –1.023 e–/Å3, respectively. Crystallographic data
(excluding structure factor) for the structures reported in this
paper have been deposited with the Cambridge Crystallographic
Data Centre as supplementary publication no. CCDC-1515174.
Copies of the data can be obtained free of charge on application
to CCDC, 12 Union Road, Cambridge CB21EZ, UK (fax:
1
h. To this mixture, 5-
1
substance (5.48 g, 74.1%) was obtained. H NMR (CDCl3, 300.4
MHz): 1.41 (t,18H, J = 7.0 Hz, CH3), 3.60 (s, 6H, CH2), 3.67
(s, 6H, CH2), 4.39 (q, 12H, J = 7.0 Hz, CH2), 7.08 (s, 3H, ArH),
8.12 (d, 6H, J = 1.5 Hz, ArH), 8.54 (d, 3H, J = 1.5 Hz, ArH). 13
C
NMR (CDCl3, 75.6 MHz): 14.0, 34.7, 35.2, 61.1, 128.17,
128.18, 128.9, 130.8, 133.8, 138.2, 139.0, 165.2. HRMS
(addition of CF3SO3Ag): calcd for C48H54S3O12109Ag+ 1027.1828;
found 1027.4070.
Synthesis of hexa alcohol 3
To a 100 mL round-bottomed flask equipped with a drying
tube were added dry THF (30 mL) and LiAlH4 (0.82 g, 0.021
mol) in an ice-salt bath. Below 0 °C, a solution of the ester 2
(2.02 g, 2.1 mmol) in 10 mL of dry THF was added dropwise and
the reaction was stirred overnight. The mixture was then heated
under reflux for 1 h and cooled. After the usual work up, a pale
Crystallographic analysis data of compound 5:17c
C18H18S3, Mr = 330.50 g mo1-1, prisms (grown from toluene),
size 0.33 0.24 0.05 mm, monoclinic, space group Pbca, a =
7.7587(14) Å, b = 16.005(3) Å, c = 25.029(5) Å,V =3108.0(10)
Å3, Z = 8, calcd. = 1.413 g cm-3, (Mo K) = 0.467 mm-1, F(000)
= 1392, T = 123(2) K using the -2 scan technique to a
maximum 2 value of 55.0°. A total of 15658 reflections were
collected. The final cycle of the full-matrix least-squares
refinement was based on 3550 observed reflections (I > 2 (I))
and 262 variable parameters and converged with unweighted and
weighted agreement factors of R = 0.0511, Rw = 0.1087 and
GOF = 1.128. The maximum and minimum peaks on the final
1
yellow sticky substance (1.00 g, 70%) was obtained. H NMR
(DMSO-d6, 300.4 MHz): δ 3.62 (s, 6H, CH2), 3.64 (s, 6H, CH2),
4.45 (d, 12H, J = 6.0 Hz, CH2), 5.14 (t, 6H, J = 6.0 Hz, OH), 7.07
(s, 3H, ArH), 7.09 (s, 3H, ArH), 7.11 (s, 3H, ArH), 7.14 (s, 3H,
ArH). 13C NMR (DMSO-d6, 75.6 MHz): δ 25.4, 63.1, 67.3,
123.4, 125.5, 128.2, 137.8, 138.8, 142.8. HRMS (addition of
CF3SO3Ag): calcd for C36H36S6Ag+ 773.1197; found 767.3600.
Synthesis of hexachloride 4