Article
Organometallics, Vol. 29, No. 23, 2010 6401
NMR (162 MHz, CDCl3, δ): 160.6. Anal. Calcd for C10H15-
P2O2NiCl: C, 37.15; H, 4.68; Cl, 10.97. Found: C, 37.12; H, 4.65;
Cl, 10.89.
Ar, 1H), 6.92 (d, JH-H=8.7 Hz, Ar, 2H), 6.65 (d, JH-H=7.9 Hz,
Ar, 2H), 6.05 (d, JH-H=8.7 Hz, Ar, 2H), 3.58 (s, OCH3, 3H).
13C{1H} NMR (101 MHz, CDCl3, δ): 166.2 (t, JC-P=11.1 Hz),
156.3, 134.9, 133.8 (t, JC-P = 8.6 Hz), 132.8, 132.6, 132.3
(t, JC-P = 7.0 Hz), 131.4, 129.4, 128.5 (t, JC-P = 5.2 Hz),
113.0, 106.2 (t, JC-P =6.6 Hz), 55.0 (OCH3). 31P{1H} NMR
(162 MHz, CDCl3, δ): 149.1. Anal. Calcd for C37H30NiO3P2S:
C, 65.80; H, 4.48. Found: C, 65.40; H, 4.43.
General Procedures for Catalytic Cross-Coupling of Aryl
Iodides and Thiols. To a 10 mL scintillation vial under an argon
atmosphere was added 1.0 mmol of thiol, 1.1 mmol of aryl
iodide, 2.0 mmol of KOH, 0.01 mmol of nickel catalyst, and
6 mL of DMF. When GC yield was desired, 1.0 mmol of
n-decane was also added as an internal standard. The vial was
sealed and then heated at 80 or 130 ꢀC until there was no thiol
left (monitored by withdrawing aliquots and analyzed by
GC-MS). The solvent was removed under vacuum, and the
residue was extracted with CH2Cl2. The combined CH2Cl2 layers
were passed through a short pad of silica gel and concentrated
under vacuum to afford the crude product. The sulfide product
was further purified by flash column chromatography. All the
isolated diaryl sulfide products were characterized by 1H NMR
and 13C{1H} NMR spectroscopy (see the Supporting Informa-
tion), and their NMR data were consistent with the literature
values.
[2,6-(Ph2PO)2C6H3]NiSPh (2a). At -78 ꢀC under an argon
atmosphere, 1a (200 mg, 0.35 mmol) and NaSPh (90%, techni-
cal grade, purchased from Sigma-Aldrich, 51 mg, 0.35 mmol)
were mixed in 20 mL of THF. The resulting mixture was warmed
to room temperature and stirred overnight. The solvent was
then removed under vacuum, and the reddish residue was
triturated with pentane. The material remaining after trituration
was treated with 20 mL of toluene, filtered through a pad of
Celite, and concentrated under vacuum. The product was
further purified via recrystallization from toluene/pentane and
isolated as a red crystalline solid (180 mg, 80% yield). X-ray
quality crystals were grown by allowing a layer of pentane to
slowly diffuse into a saturated toluene solution of 2a. 1H NMR
(400 MHz, CD2Cl2, δ): 7.83-7.78 (m, Ar, 8H), 7.53-7.49 (m,
Ar, 4H), 7.43-7.40 (m, Ar, 8H), 7.08 (t, Ar, JH-H=8.0 Hz, 1H),
6.99 (d, Ar, JH-H=8.0 Hz, 2H), 6.65-6.61 (m, Ar, 3H), 6.49
(t, Ar, JH-H=8.0 Hz, 2H). 13C{1H} NMR (101 MHz, CDCl3, δ):
166.3 (t, JC-P=11.1 Hz), 143.7 (t, JC-P=7.0 Hz), 134.0, 132.8,
Independent Synthesis of [2,6-(Ph2PO)2C6H3]NiP(O)Ph2 (5a).
Ph2P(O)H (202 mg, 1.0 mmol) was dissolved in 30 mL of THF
under an argon atmosphere, and KOH (56 mg, 1.0 mmol) was
added. The mixture was stirred at room temperature for 16 h,
after which the solvent was removed under vacuum. The result-
ing white solid was mixed with 1a (200 mg, 0.35 mmol) in 30 mL
of toluene and refluxed under argon for 6 h. The mixture was
then cooled to room temperature and filtered through a pad of
Celite. Removal of toluene under vacuum afforded a yellow
solid, which was washed with pentane (20 mL ꢀ 3) to produce
5a, showing >95% pure by NMR (110 mg, 43% yield). X-ray
quality crystals of 5a were obtained from evaporating the
benzene-d6 solution of 5a. 1H NMR (400 MHz, C6D6, δ):
8.05-7.95 (m, Ar, 8H), 7.57-7.53 (m, Ar, 4H), 7.10-7.04
(m, Ar, 13H), 6.91-6.79 (m, Ar, 8H). 13C{1H} NMR (101 MHz,
C6D6, δ): 166.2 (t, JC-P=9.3 Hz, Ar), 145.7 (d, JC-P=39.1 Hz),
132.9 (t, JC-P=6.9 Hz), 132.3 (t, JC-P=26.5 Hz), 131.3, 131.2,
130.4 (d, JC-P=11.3 Hz), 128.4 (t, JC-P=5.3 Hz), 127.9, 127.7,
127.3 (d, JC-P=9.4 Hz), 106.4 (t, JC-P=5.9 Hz). 31P{1H} NMR
(162 MHz, C6D6, δ): 152.7 (d, 2JP-P=53.7 Hz, pincer OPPh2,
2P), 64.9 (t, 2JP-P=53.7 Hz, NiP(O)Ph2, 1P). IR (in toluene):
1178 cm-1 (PdO). This complex decomposed rapidly upon
standing, precluding reliable elemental and mass spectral
analyses.
X-ray Structure Determinations. Crystal data collection and
refinement parameters are summarized in Table 1. Intensity
data were collected at 150 K on a Bruker SMART6000 CCD
diffractometer using graphite-monochromated Cu KR radia-
˚
tion, λ=1.54178 A. The data frames were processed using the
program SAINT. The data were corrected for decay, Lorentz
and polarization effects, as well as absorption and beam correc-
tions based on the multiscan technique used in SADABS. The
structures were solved by a combination of direct methods in
SHELXTL and the difference Fourier technique and refined by
full-matrix least-squares procedures. Non-hydrogen atoms were
refined with anisotropic displacement parameters. The H-atoms
were either located or calculated and subsequently treated with a
riding model. Compound 1b crystallized as two independent
molecules in the lattice with minimal variation in conformation.
Complex 4a crystallized as both plates and needles showing
different unit cell parameters. Compound 5a cocrystallized with
the solvent molecule (C6D6).
132.6, 132.3 (t, JC-P =7.0 Hz), 131.5, 129.6, 128.6 (t, JC-P
=
6.0 Hz), 127.2, 122.9, 106.2 (t, JC-P=7.0 Hz). 31P{1H} NMR
(162 MHz, CD2Cl2, δ): 149.0. Anal. Calcd for C36H28P2O2NiS:
C, 67.00; H, 4.37. Found: C, 67.04; H, 4.29.
[2,6-(Ph2PO)2C6H3]NiSC6H4CH3 (3a). To a mixture of
sodium hydride (48 mg, 2.0 mmol) and THF (30 mL) was
added 4-methylbenzenethiol (248 mg, 2.0 mmol) at 0 ꢀC under
an argon atmosphere. The resulting mixture was warmed
to room temperature and stirred for 1 h before 1a (572 mg,
1.0 mmol) was added. After stirring at room temperature for
another 2 h, the volatiles were removed under vacuum and the
residue was extracted with toluene and filtered through a pad
of Celite. Removal of toluene under vacuum resulted in a red
solid, which was recrystallized from CH2Cl2/hexanes (1:2) to
produce red crystals of 3a (508 mg, 77% yield). 1H NMR (400
MHz, CDCl3, δ): 7.84-7.80 (m, Ar, 8H), 7.48-7.35 (m, Ar,
12H), 7.07 (t, JH-H=7.9 Hz, Ar, 1H), 6.91 (d, JH-H=7.9 Hz,
Acknowledgment. We thank the National Science
Foundation (CAREER Award CHE-0952083 and
NSF-REU program CHE-0754114) and the donors of
the American Chemical Society Petroleum Research
Fund (49646-DNI3) for support of this research. J.Z.
thanks the University of Cincinnati University Research
Council for a postdoctoral research fellowship. X-ray
data were collected on a Bruker SMART6000 diffractom-
eter that was purchased with funding provided by an
NSF-MRI grant (CHE-0215950).
Ar, 2H), 6.64 (d, JH-H = 7.9 Hz, Ar, 2H), 6.24 (d, JH-H
=
7.9 Hz, Ar, 2H), 2.01 (s, CH3, 3H). 13C{1H} NMR (101 MHz,
CDCl3, δ): 166.2 (t, JC-P=11.1 Hz), 139.7 (t, JC-P=8.0 Hz),
133.9, 132.8, 132.6, 132.5, 132.3 (t, JC-P = 7.2 Hz), 131.3,
129.4, 128.5 (t, JC-P=5.3 Hz), 128.0, 106.1 (t, JC-P=6.7 Hz),
20.8 (CH3). 31P{1H} NMR (162 MHz, CDCl3, δ): 148.5. Anal.
Calcd for C37H30NiO2P2S: C, 67.40; H, 4.59. Found: C, 67.34;
H, 4.49.
[2,6-(Ph2PO)2C6H3]NiSC6H4OCH3 (4a) was prepared in
64% yield by a procedure similar to that used for 3a. X-ray-
quality crystals of 4a were obtained from the recrystallization of
4a in CH2Cl2/hexanes. 1H NMR (400 MHz, CDCl3, δ): 7.86-
7.82 (m, Ar, 8H), 7.50-7.38 (m, Ar, 12H), 7.07 (t, JH-H=7.9 Hz,
Supporting Information Available: NMR spectra of the iso-
lated sulfide compounds and X-ray crystallographic data in CIF
format. This material is available free of charge via the Internet