Acyclic Diselenodithioether Ligand With Bulky Substituents 553
prior to use by using an Ultimate Solvent System
(Glass Contour Company) Laguna Beach, CA, USA
[30], and other solvents were used without purifica-
tion. Preparative gel permeation liquid chromatog-
raphy (GPLC) was performed on an LC-908 or LC-
918 instrument with JAI gel 1H+2H columns (Japan
Analytical Industry) using chloroform as an eluent.
Short column chromatography was performed with
Nacalai Tesque Silica Gel 60. The 1H NMR (300
MHz) and 13C NMR (75 MHz) spectra were measured
in CDCl3 with a JEOL AL-300 spectrometer using
CHCl3 (7.25 ppm) as internal standards for 1H NMR
Synthesis of Selenide 5
A mixture of Tbt-substituted diselenide 4 (8.62
g, 6.83 mmol), Cu2O (2.00 g, 14.0 mmol), and
1,2-diiodobenzene (5.0 mg, 15 mmol) in 2,4,6-
trimethylpyridine (60 mL) was refluxed for 6 h. The
reaction mixture was passed through a short col-
umn (SiO2, CHCl3) to remove inorganic salts. All
fractions were collected and washed with a 1.0 M
aqueous solution of HCl four times (100 mL × 4).
The organic layer was passed through a short col-
umn (SiO2, CHCl3) to remove water and inorganic
salts. After the eluate was evaporated, the reprecip-
itation from CH2Cl2/CH3CN gave selenide 5 (7.2 g,
8.6 mmol, 63%) as colorless crystals. 5: mp 180.8–
spectroscopy, and CDCl3 (77.0 ppm) as those for 13
C
NMR spectroscopy. The 77Se NMR (95 MHz) spec-
tra were measured in CDCl3 or C2D2Cl4 with a JEOL
JNM AL-300 spectrometer using diphenyl diselenide
(460 ppm) as an external standard. Mass spectral
data were obtained on a JEOL JMS-700 spectrome-
ter. All melting points were determined on a Yanaco
micro melting point apparatus and are uncorrected.
Elemental analyses were performed at the Micro-
analytical Laboratory of the Institute for Chemical
Research, Kyoto University.
1
182.0˚C. H NMR (300 MHz, CDCl3) δ-0.03 (36H,
s), 0.06 (18H, s), 1.36 (1H, s), 2.71 (2H, brs), 6.42
(1H, brs), 6.55 (1H, brs), 6.79 (1H, ddd, J = 7.8, 7.8,
1.5 Hz), 6.80 (1H, dd, J = 7.8, 1.5 Hz), 7.01 (1H,
ddd, J = 7.8, 7.8, 1.5 Hz), 7.71 (1H, dd, J = 7.8, 1.5
Hz); 13C NMR (75 MHz, CDCl3) δ 0.79 (q), 29.51 (d),
30.56 (d), 98.56 (s), 122.14 (d), 126.88 (d), 128.24 (d),
129.39 (s), 131.09 (d), 139.10 (d), 141.27 (s), 144.67
(s), 150.22 (s); 77Se NMR (57 MHz, CDCl3) δ 354
(s); HRMS (FAB) m/z calcd for C33H63ISeSi6 [M]+:
834.1755. Found: 834.1758.
Synthesis of Diselenide 4
To a THF solution (160 mL) of TbtBr (10.0 g,
15.8 mmol) was gradually added t-BuLi (2.2 M pen-
tane solution, 15.8 mL, 34.8 mmol) at −78◦C. Af-
ter stirring for 1 h at this temperature, Se (1.35 g,
17.1 mmol) was added to the yellow solution. The
reaction mixture was stirred at −78◦C for 1 h and
then at room temperature for 3 h. The resulting dark-
brown solution was added to a THF solution (40 mL)
of LiAlH4 (1.0 g, 26.4 mmol) at 0◦C. The reaction
mixture was stirred for 14 h at room temperature.
After removal of the solvents under reduced pres-
sure, ice water was added to the residue under air.
The mixture was extracted with hexane (250 mL).
After removal of the solvents under vacuum, the
residue was passed through a short column (SiO2,
hexane) to remove the remaining water. The evap-
oration of the eluate gave diselenide 4 (9.75 g, 7.72
mmol, 98%) as purple crystals. 4: mp 242.8–243.8˚C.
1H NMR (300 MHz, CDCl3) δ 0.04 (72H, s), 0.07 (36H,
s), 1.32 (2H, s), 2.77 (2H, brs), 2.85 (2H, brs), 6.36
(2H, brs), 6.49 (2H, brs); 13C NMR (75 MHz, CDCl3)
δ 0.76 (q), 0.81 (q), 1.07 (q), 30.45 (d), 31.36 (d),
31.48 (d), 121.73 (d), 126.67 (d), 128.72 (s), 143.87
(s), 149.73 (s), 149.96 (s); 77Se NMR (57 MHz, CDCl3)
δ 367; HRMS (FAB) m/z calcd for C54H118Se2Si12
[M]+: 1262.4795. Found: 1262.4810. Anal. Calcd for
C54H118Se2Si12: C, 51.37; H, 9.42%. Found: C, 51.49;
H, 9.42%.
Synthesis of Diselenodithioether 3
A mixture of Tbt-substituted selenide 5 (200 mg,
0.240 mmol), Cu2O (34 mg, 0.24 mmol), and
1,2-benzenedithiol (17 mg, 0.12 mmol) in 2,4,6-
trimethylpyridine (15 mL) was refluxed for 6 h.
The reaction mixture was subjected to short column
chromatography (SiO2, CHCl3) to remove inorganic
salts. The mixture was washed with a 1.0 M aque-
ous solution of HCl four times (100 mL × 4).
The organic layer was passed through a short col-
umn (SiO2, CHCl3) to remove water and inor-
ganic salts, and then the eluate was evaporated.
The residue was subjected to GPLC (CHCl3) to
give diselenodithioether 3 (131 mg, 0.084 mmol,
70%) as colorless crystals. 3: mp 107.8–108.5◦C.
1H NMR (300 MHz, CDCl3) δ–0.04 (72H, s), 0.07
(36H, s), 1.37 (2H, s), 2.76 (4H, brs), 6.43 (2H,
brs), 6.57 (2H, brs), 6.80 (2H, m), 6.95–7.14 (8H,
m), 7.24 (2H, m); 13C NMR (75 MHz, CDCl3) δ
0.49 (q), 0.84 (q), 29.23 (d × 2), 30.51 (d), 122.21
(d), 126.16 (d), 126.45 (s), 127.06 (d), 127.54 (d),
128.20 (d), 130.14 (d), 130.48 (d), 132.24 (s), 133.24
(d), 136.95 (s), 139.41 (s), 144.36 (s), 150.60 (s ×
2); 77Se NMR (57 MHz, CDCl3) δ 282 (s); 77Se NMR
(57 MHz, C2D2Cl4, 100◦C) δ 290 (s); HRMS (FAB) m/z
calcd for C72H130S2Se2Si12 [M]+: 1554.5176. Found:
Heteroatom Chemistry DOI 10.1002/hc