LETTER
Ligand-Free C–S Bond Formation
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(10) General Experimental Procedure
All reagents and solvents were pure analytical-grade
materials purchased from commercial sources and were used
without further purification. The 1H NMR and 13C NMR
spectra were recorded in CDCl3 on a 300 MHz instrument
with TMS as internal standard. High-resolution mass spectra
(HRMS) were determined on a Micromass GCT-MS mass
spectrometer. Thin-layer chromatography was carried out
with 0.2 mm thick SiO2 plates (GF254). The columns were
hand packed with silica gel 60 (200–300). All reactions were
carried out in a Schlenk tube equipped with a magnetic stir
bar under Ar atmosphere. A Schlenk tube was charged with
Cu2O (0.05 mmol), KOH (2 mmol) and solid substrate, if
present. Then, liquid reagents (aryl or heteroaryl halide, 1
mmol; thiol, 1.1 mmol), solvent (1 mL) were added under
Ar. The reaction vessel was closed and placed under stirring
in a preheated oil bath at 80 °C. The reaction mixture was
stirred for 24 h. The resulting suspension was cooled to r.t.
and filtered through a pad of filter paper with the help of
EtOAc (10 mL). The filtrate was concentrated and the
residue was purified by silica gel chromatography.
(4-Methoxyphenyl)phenylsulfane (Entry 2, Table 1)
1H NMR (300 MHz, CDCl3): d = 3.78 (s, 3 H), 6.98 (d,
J = 8.7 Hz, 2 H), 7.17–7.21 (m, 5 H), 7.40 (d, J = 9.0 Hz,
2 H) ppm. 13C NMR (75 MHz, CDCl3): d = 55.2, 115.0,
124.2, 125.7, 128.2, 128.9, 135.3, 138.6, 159.8 ppm. HRMS:
m/z calcd for C13H12OS: 216.0609; found: 216.0613.
Phenyl(p-tolyl)sulfane (entry 20, Table 1)
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1H NMR (300 MHz, CDCl3): d = 2.31 (s, 3 H), 7.09–7.29 (m,
9 H) ppm. 13C NMR (75 MHz, CDCl3): d = 21.1, 126.4,
129.0, 129.8, 130.1, 131.4, 132.3, 137.2, 137.5 ppm. HRMS:
m/z calcd for C13H12S: 200.0660; found: 200.0652.
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(11) No Cu was found in pure diphenylsulfane (entry 4, Table 1)
with X-radial fluorescence-spectrum determining.
Synlett 2008, No. 19, 3063–3067 © Thieme Stuttgart · New York