Organometallics
Article
acetone (40 mL) resulted in precipitation of a pale yellow solid, which
was separated by filtration and dried under vacuum for 1 h. The solid
was recrystallized by dissolution in methanol and precipitated by slow
diffusion of diethyl ether into the methanol solution (1 day). The
yellow powder thus obtained was filtered and dried overnight under
NHC catalysts in the Suzuki−Miyaura reaction requires further
attention.
EXPERIMENTAL SECTION
■
1
vacuum at 60 °C (36.5 mg, 62%). H NMR (300 MHz, dmso-d6): δ
Reagents and General Techniques. All reactions were carried
out under an argon atmosphere using sealed ampules or standard
Schlenk techniques. Unless otherwise stated, reagents and solvents
were used as received from commercial sources. Solvents (synthesis
grade) were deoxygenated before use. Dimethyl sulfoxide (dmso) was
stirred over calcium hydride for 24 h and distilled under vacuum under
an argon atmosphere. Deionized water (type II quality) was obtained
using a Millipore Elix 10 UV water purification system. The
monosodium salt of 1,3-(4-sulfonate-2,6-diisopropylphenyl)-
imidazolium (HIPr-SO3−) was prepared as described in the
literature.15 1H, 13C, and 31P NMR spectra were recorded with a
Varian Mercury 300, Unity 300, or Unity 500 Plus spectrometer.
Chemical shifts (δ, ppm) are quoted relative to SiMe4 (1H, 13C) or
85% H3PO4 (31P) and were measured by internal referencing to the
7.75 (d, 2H, 5JP−H = 1, Imz), 7.61 (s, 4H, Ar), 7.26−7.36 (m, 9H, Ph),
7.21−7.18 (m, 6H, Ph), 3.10 (sept, 3J = 6.7, 4H, CHMe2), 1.19 (d, 3J =
3
1
6.6, 12H, CHMe2), 1.0 (d, J = 6.9, 12H, CHMe2). H NMR (300
5
MHz, D2O): δ 7.66 (s, 4H, Ar), 7.45 (d, 2H, JP−H = 1.4, Imz), 7.24
(m, 3H, Ph), 7.15−7.06 (m, 12H, Ph), 2.85 (sept, 3J = 6.7, 4H,
3
3
CHMe2), 1.09 (d, J = 6.7, 12H, CHMe2), 0.90 (d, J = 6.7, 12H,
CHMe2). 13C{1H} NMR (75 MHz, dmso-d6): δ 167.8 (d, JC−P
=
2
198.6, Imz C2), 148.6 (s, Ar C4), 145.1 (s, Ar C2), 134.9 (s, Ar C1),
134.0 (d, 2JC−P = 10.7, Ph C2), 129.5 (s, Ph C4), 129.3 (d, 1JC−P = 44,
Ph C1), 127.3 (d, JC−P = 9.7, Ph C3), 125.1 (d, J = 5.5, Imz C4−5),
120.3 (s, Ar C3), 27.7 (s, CHMe2), 25.4 (s, CHMe2), 22.2 (s, CHMe2).
31P{1H} NMR (121 MHz, dmso-d6): δ 20.2 (s). 31P{1H} NMR (121
MHz, D2O): δ 20.9 (s). ESI-MS (negative ion, H2O) m/z: 1007.1100
[M − Na]− (calcd 1007.1085) 3%; 985.1268 [M − 2Na + H]− (calcd
985.1265) 76%; [M − 2Na − PPh3 + H]− 723.0352 (calcd 723.0354)
100%.
3
4
1
13C or residual H resonances of the deuterated solvent or by the
substitution method in the case of 31P. Coupling constants (J) are
given in hertz. When required, two-dimensional H−13C HSQC and
1
Na3[(IPr-SO3)PdCl2{P(C6H5)2(C6H4-m-SO3)}] (3). This compound
was prepared starting from 1 (10.3 mg, 12.4 μmol) and PPh2(C6H4-
m-SO3Na) (4.5 mg, 12.4 μmol) by a similar method to that described
above for 2. The yellow crystals thus obtained were filtered and dried
HMBC experiments were carried out for the unequivocal assignment
of H and 13C resonances. The Analytical Services of the Universidad
1
́
de Alcala performed the C, H, N, and S analyses using a LECO
CHNSO-932 microanalyzer and the ESI mass spectra using an Agilent
G3250AA LC/MSD TOF Multi mass spectrometer. Some ESI mass
spectra were recorded by the SIDI Service of the Universidad
1
overnight under vacuum at 60 °C (4.90 mg, 35%). H NMR (300
MHz, dmso-d6): δ 7.75 (d, 2H, 5JP−H = 1.3, Imz), 7.62 (s, 4H, Ar H3),
7.56 (ddd, 3JH−H = 7.7, 4JH−H = 1.6, 1H, C6H3SO3− H4), 7.47 (dt, 3JP−H
́
Autonoma de Madrid using an Applied Biosystems QSTAR mass
spectrometer. GC-MS analyses were performed using an Agilent
7820/5975C system.
= 12.5, 3JH−H = 7.8, 4JH−H = 1.6, 1H, C6H3SO3− H6), 7.37 (td, 4JP−H
=
2.5, 3JH−H = 7.5, 1H, C6H3SO3− H5), 7.33−7.27 (m, 6H, Ph), 7.25 (dt,
4
−
3JP−H = 8.8, JH−H= 1.7, 1H, C6H3SO3 H2), 7.16−7.10 (m, 4H, Ph),
Na3[(IPr-SO3)PdCl3] (1). The monosodium salt of 1,3-(4-sulfonate-
2,6-diisopropylphenyl)imidazolium (0.4109 g, 0.720 mmol), palladium
dichloride (0.1550 g, 0.874 mmol), sodium hydrogen carbonate
(0.0890 g, 1.06 mmol), and sodium chloride (0.0600 g, 1.03 mmol)
were introduced into a 100 mL Schlenk. Dry dmso (15 mL) was then
added using a syringe, and the mixture was stirred vigorously for 2 days
at 90 °C. The dmso solution was subsequently concentrated to 8−10
mL, and tert-butanol was slowly added to form a double layer. Slow
crystallization from the double layer (1 day) afforded yellowish
crystals, which were separated by filtration and dissolved again in dry
dmso. The solution was filtered through diatomaceous earth to remove
any traces of metallic palladium. Complex 1 precipitated from this
solution as a yellow solid by addition of tert-butanol and was dried
under vacuum overnight at 160 °C (0.390 g, 54% based on Pd). A
reasonable agreement between the number of solvent molecules
3
3
3.10 (sept, JH−H = 6.6, 4H, CHMe2), 1.20 (d, JH−H = 6.6, 12H,
3
1
CHMe2), 1.04 (d, JH−H = 6.9, 12H, CHMe2). H NMR (300 MHz,
D2O): δ 7.67 (s, 4H, Ar H3), 7.47 (d, 2H, 5JP−H = 1.4, Imz), 7.31−7.12
−
(m, 14H, Ph + C6H3SO3 ), 2.86 (sept, 3J = 6.7, 4H, CHMe2), 1.11 (d,
3J = 6.7, 12H, CHMe2), 0.91 (d, J = 6.7, 12H, CHMe2). 13C{1H}
3
NMR (75 MHz, dmso-d6): δ 167.7 (d, 2JC−P = 198, Imz C2), 148.5 (s,
Ar C4), 147,0 (d, J = 6.2, C6H3SO3− C3), 145.1 (s, Ar C2), 136.5 (d, J
−
2
= 20.3, C6H3SO3 C6), 134.9 (s, Ar C1), 133.9 (d, JC−P = 10.5, Ph
C2), 129.5 (s), 129.1 (d, 1JC−P = 42.5, Ph C1), 128.9 (s, Ph C4), 128.4
3
−
(s), 127.3 (d, JC−P = 9.8 Hz, Ph C3), 127.0 (s), 126.9 (s, C6H3SO3
C4), 125.2 (d, 4J = 5.5, Imz C4−5), 120.3 (s, Ar C3), 27.7 (s, CHMe2),
25.4 (s, CHMe2), 22.2 (s, CHMe2). 31P{1H} NMR (121 MHz, dmso-
d6): δ 20.7 (s). 31P{1H} NMR (121 MHz, D2O): δ 21.2 (s). ESI-MS
(negative ion, H2O) m/z: 1109.0474 [M − Na]− (calcd 1109.0472)
8%; 1087.0652 [M − 2Na + H]− (calcd 1087.0653) 4%; 1065.0838
[M − 3Na + 2H]− (calcd 1065.0833) 5%; 723.0355 [M − TPPMS −
2Na + H]− (calcd 723.0354) 100%; [M − TPPMS − Na]− 745.0191
(calcd 745.0173) 56%.
1
detected by H NMR spectroscopy and the elemental analysis results
was obtained as follows. The solid was dissolved in dmso and
crystallized by slow diffusion of tert-butanol. The crystals were crushed
and dried for 12 h at 160 °C under high vacuum. Anal. Calcd (%) for
C35H58Cl3N2Na3O10PdS6 (1·4dmso, 1140.98): C, 36.84; H, 5.12; N,
Na2[(IPr-SO3)PdCl2(NC6H4-4-CH3)] (4). A mixture of compound 1
(50.5 mg, 61.0 μmol) and 4-picoline (5.7 mg, 61 μmol) was stirred for
5 min in dmso (0.5 mL) at room temperature under an argon
atmosphere. Addition of cold diethyl ether (20 mL, −15 °C) resulted
in precipitation of an orange solid, which was separated by filtration
1
2.46; S, 16.86. Found: C, 36.55; H, 5.19; N, 2.55; S, 15.02. H NMR
(500 MHz, D2O): δ 7.65 (s, 2H, Ar), 7.47 (s, 1H, Imz), 2.74 (sept, J =
6.6, 2H, CHMe2), 1.26 (d, 3J = 6.6, 6H, CHMe2), 0.93 (d, 3J = 6.9, 6H,
CHMe2). 1H NMR (300 MHz, dmso-d6): δ 7.78 (s, 1H, Imz), 7.57 (s,
3
1
2H, Ar), 2.96 (sept J = 6.9, 2H, CHMe2), 1.31 (d, J = 6.6, 6H,
and dried for 1 h under vacuum at 40 °C (40 mg, 76%). H NMR
3
CHMe2), 1.03 (d, J = 6.9, 6H, CHMe2). 13C{1H} NMR (125 MHz,
3
(300 MHz, dmso-d6): δ 8.21 (d, J = 6.6, 2H, py-4-Me H2), 7.76 (s,
D2O): δ 148.3 (s, Ar C2), 144.6 (s, Ar C4), 136.9 (s, Ar C1), 127.2 (s,
Imz C4,5), 121.6 (s, Ar C3), 29.3 (s, CHMe2), 25,2 (s, CHMe2), 22.5 (s,
CHMe2). 13C{1H} NMR (75 MHz, dmso-d6): δ 148.8 (s, Ar C4),
145.3 (s, Ar C2), 134.3 (s, Ar C1), 126.2 (s, Imz C4,5), 120.4 (s, Ar C3),
27.7 (s, CHMe2), 25.4 (s, CHMe2), 22.4 (s, CHMe2). ESI-MS
(negative ion, MeOH) m/z: 802.9760 [M − Na]− (calcd 802.9760)
10%; 389.9942 [M − 2Na]2− (calcd 389.9934) 3%; 723.0361 [M −
3Na − Cl + H]− (calcd 723.0354) 5%; 745.0197 [M − 2Na − Cl]−
(7%) (calcd 745.0173).
2H, Imz), 7.57 (s, 4H, Ar H3), 7.16 (d, 3J = 6.3, 2H, py-4-Me H3), 3.06
3
3
(sept, J = 6.3, 4H, CHMe2), 2.23 (s, 3H, py-4-Me), 1.33 (d, J = 6.3,
12H, CHMe2), 1.05 (d, J = 6.6, 12H, CHMe2). 13C{1H} NMR (50
3
MHz, dmso-d6): δ 152.7 (s, Imz C2), 149.5 (s, py-4-Me C2), 149.3 (s,
py-4-Me C4), 148.6 (s, Ar C4), 145.2 (s, Ar C2), 134.6 (s, Ar C1), 125.2
(s, Imz C4−5), 124.6 (s, py-4-Me C3), 120.4 (s, Ar C3), 27.7 (s,
CHMe2), 25.4 (s, CHMe2), 22.5 (s, CHMe2), 19.9 (s, py-4-Me Me).
ESI-MS (negative ion, H2O) m/z: 816.0933 [M − 2Na + H]− (calcd
816.0932) 29%; 780.1178 [M − 2Na − Cl]− (calcd 780.1166) 13%;
723.0360 [M − C6H7N − 2Na + H]− (calcd 723.0354) 100%.
General Procedure for the Suzuki−Miyaura Cross-Coupling
Reactions. All operations were performed under an argon
atmosphere using deoxygenated solvents. The catalyst was added in
Na2[(IPr-SO3)PdCl2(PPh3)] (2). A solution of compound 1 (47.2 mg,
57.0 μmol) and PPh3 (15.0 mg, 57.0 μmol) in dmso (1 mL) was
stirred for 5 min at room temperature. The solvent was then
evaporated under vacuum at 80 °C to almost dryness. The addition of
G
Organometallics XXXX, XXX, XXX−XXX