Trifluoromethylphenyl Palladium(II) Complexes
6.7 Hz, 2 H, HAr), 4.69 (m, 2 H, HFc), 4.50 (m, 2 H HFc), 4.16 (m, 2 H, HFc),
3.62 (m, 2H, HFc). 31P{1H} NMR: (162 MHz, CDCl3, 297 K) δ 30.1 (d,
2JPP ϭ 32.4 Hz), 9.6 (d). 19F{1H} NMR: (400 MHz, CDCl3, 300 K) δ
Ϫ62.0 ppm.
Recrystallization from dichloromethane by slow diffusion of n-pen-
tane resulted in the formation of colourless crystals. Yield: 2.96 g
(80 %). Elemental analysis, calcd. for C43H34BrF3P2Pd (856.01): C
60.34, H 4.00; found: C 60.01, H 4.27 %.
1H NMR (400 MHz, CDCl3, 301 K): δ 7.50-7.40 (m, 12 H, H-o), 7.30-7.22
(m, 6 H, H-p), 7.20-7.13 (m, 12 H, H-m), 6.67 (d, 3JH,H ϭ 8.0 Hz, 2 H, H-c),
6.33 ppm (d, 2 H, H-b). 13C{1H} NMR (162 MHz, CDCl3, 297 K): δ 136.4 (t,
JPC ϭ 4.1 Hz, C-b), 135.0 (t, JPC ϭ 5.2 Hz, C-o), 131.7 (t, C-a), 130.5 (s, C-
p), 127.8 (t, JPC ϭ 12.9 Hz, C-m), 123.4 (s, C-c), not detected: C-i, C-d,
C-e. 1P{1H} NMR (162 MHz, CDCl3, 297 K): δ 23.7 ppm. 19F{1H} NMR:
(400 MHz, CDCl3, 301 K) δ Ϫ62.1 ppm.
X-ray structure analyses
Crystal data and refinement parameters are collected in Table 1.
The structures were solved using direct methods (for compound
6 SIR92 [6] and for compound 8 SHELXS-97 [7]), completed by
subsequent difference Fourier syntheses, and refined by full-matrix
least-squares procedures [7]. Semiempirical absorption corrections
from equivalents (Multiscan) were carried out [8]. All non-hydro-
gen atoms were refined with anisotropic displacement parameters.
All hydrogen atoms positions were calculated in ideal positions
(riding model). CCDC-698566 (6) and CCDC-698567 (8) contain
the supplementary crystallographic data for this paper. These data
can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Sketch 1
Table 1 Summary of the crystallographic data and details of data
collection and refinement for compounds 6 and 8.
trans-Fluoro(4-trifluoromethylphenyl)bistriphenylphosphine-
palladium(II) (3F). 1.58 g (2.00 mmol) of 3 and 0.38 g (3.00 mmol)
AgF were suspended in 25 mL of benzene and treated in the dark
in an ultra sonic bath for 6 h. After filtration of the solids, the
solvent was reduced in vacuum to about 4 mL. Slow diffusion of
n-pentane into this solution resulted in the formation of colourless
crystals. Yield: 1.35 g (85 %).
compound
6
8
molecular formula
formula weight
crystal size /mm
crystal system
space group
T /K
C52H42BrF3OP2Pd
988.11
0.15x0.09x0.08
triclinic
P1
150
10.6171(4)
12.7537(5)
17.1476(7)
72.473(4)
83.069(3)
79.131(3)
2169.33(15)
1.513
C41H32BrF3FeP2Pd
885.77
0.23x0.07x0.06
triclinic
P1
150
11.0514(9)
12.0598(11)
14.3538(10)
71.655(7)
88.801(6)
78.200(7)
1775.5(3)
1.657
¯
¯
˚
1H NMR (400 MHz, CDCl3, 301 K): δ 7.70-7.23 (m, 30 H, HAr), 6.73 (d,
a /A
˚
3
3JHH ϭ 8.3 Hz, 2 H), 6.39 ppm (d, JHH ϭ 8.3 Hz, 2H). 13C{1H} NMR
b /A
˚
c /A
(162 MHz, CDCl3, 297 K): δ 136.1 (t, JPC ϭ 4.0 Hz, C-b), 134.2 (t, JPC
12.4 Hz, C-o), 130.6 (t, JPC ϭ 43.4 Hz, C-a), 130.0 (s, C-p), 127.9 (t, JPC
ϭ
ϭ
Ͱ /°
β /°
γ /°
10.2 Hz, C-m), 126.0 (s, C-c), 122.9 (s, C-i), not detected: C-d, C-e. 31P{1H}
NMR (162 MHz, CDCl3, 297 K): δ 19.5 (d, 2JPF ϭ 13.1 Hz). 19F{1H} NMR:
(400 MHz, C6D6, 301 K) δ Ϫ62.1 (CF3), Ϫ274.1 ppm (t).
3
˚
V /A
Dcalc /(g cmϪ3
Z
)
2
2
trans-Bromo(4-trifluoromethylphenyl)(Xantphos)palladium(II) (6).
1.15 g (2.00 mmol) of Pd(dba)2 (4) and 1.16 mg of Xantphos
(2.10 mmol) were dissolved in 60 mL of benzene in a Schlenk tube
and treated with 1.12 mL (8.00 mmol) of 1. The mixture was stirred
for 4 h at 80 °C. After cooling to room temperature, the solution
was filtered over Celite® and the solvent was reduced to about
5 mL in vacuum. Slow diffusion of n-pentane into this solution
resulted in the formation of yellow crystals. Yield: 1.35 g (80 %).
Elemental analysis, calcd. for C46H36BrF3OP2Pd·(C6H6) (988.17):
C 63.20, H 4.28; found: C 62.79, H 3.99 %.
μcalc /mmϪ1
5.648
9.908
diffractometer
Oxford Diffraction
Gemini S Ultra
Ω-scan
Oxford Diffraction
Gemini S Ultra
Ω-scan
scan type
radiation
° range /°
CuKα
4.25-62.66
18227
6817
543
0.0355
0.0286
0.0807
0.0786
CuKα
3.95-62.78
16166
5597
442
0.0263
0.0222
0.0538
0.0529
reflexions measd.
independent refl.
refined parameters
Ra) (all data)
Ra) (I>2σ(I))
b)
ωR2b) (all data)
3
1H NMR (400 MHz, CDCl3, 300 K): δ 7.62 (dd, JHH ϭ 7.6, 1.6 Hz, 2 H,
ωR2 (I>2σ(I))
GOFc)
1.029
0.390/Ϫ1.116
0.963
0.302/Ϫ0.488
3
HAr), 7.34-7.10 (m, 24 H, HAr), 6.66 (brs, 2 H, HAr), 6.29 (brs, JHH
ϭ
3
˚
3
res. el. dens. (e/A )
7.2 Hz, 1 H, HAr), 6.10 (t, JHH ϭ 7.3 Hz, 2 H, HAr), 1.70 (s, 6 H, CH3).
13C{1H} NMR (400 MHz, CDCl3, 300 K): δ 165.5 (s), 155.5 (s), (t, JPC
ϭ
2 1/2
a) R
ϭ ϭ ] . ϭ
ΣʈFoΗϪΗFcʈ/ΣΗFoΗ. b) ωR2 [Σω(Fo2ϪFc2)2/ΣωFo c) GOF
5.5 Hz), 134. 8 (brs), 131.9 (s), 131.0 (t, JPC ϭ22.0 Hz), 129.8 (s), 129.0 (s),
128.3 (t, JPC ϭ 4.6 Hz), 128.0 (s), 126.3 (s), 124.4 (s), 123.5 (s), 122.1 (s) (t,
JPC ϭ 21.1 Hz), 121.6 (s), 36.2 (s), 28.5 (s), not detected: C-CF3. 31P{1H}
NMR (162 MHz, CD2Cl2, 297 K): δ 8.3 (s). 19F{1H} NMR (400 MHz,
CDCl3, 300 K): δ Ϫ62.0 ppm.
[Σω(Fo2ϪFc2)2/(n-p)]1/2
.
Results and Discussion
cis-(1,1Ј-Bisdiphenylphosphinoferrocene)bromo(4-trifluoromethyl-
phenyl)palladium(II) (8). 0.61 g (0.75 mmol) of 3 were suspended in
10 mL of THF and treated with 0.44 g (0.80 mmol) 1,1Ј-bisdiphen-
ylphosphinoferrocene (dppf, 7). The solution was stirred for 1 h at
room temperature. The product was precipitated by the addition
of n-pentane. Yield: 0.59 g (83 %). Elemental analysis, calcd. for
C41H32BrF3FeP2Pd (885.82): C 55.59, H 3.64; found: C 55.54, H
3.63 %.
Functionalization of arylhalides by electron withdrawing
groups generally enhances the reactivity of these substrates
against attack of nucleophiles [9]. Therefore 4-bromotri-
fluoromethylbenzene undergoes rapid oxidative addition to
palladium(0). Depending on the phosphine ligand applied,
these transformations may lead to mono- or dinuclear prod-
ucts via electron deficient palladium(0) intermediates [9f,
10].
1HNMR (400 MHz, CDCl3, 300 K) δ 8.06-8.03 (m, 6 H, HAr), 7.50-7.47 (m,
4 H, HAr), 7.36-7.30 (m, 6 H, HAr), 7.13-7.10 (m, 6 H, HAr), 6.77 (d, 3JHH ϭ
Z. Anorg. Allg. Chem. 2008, 2380Ϫ2384
© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
2381