Synthesis of (2-X,3-Y-Phenyl)dimethylphosphanes (X, Y = Me2P, H; Me2P, F; Br, F) and their complexes with PdCl2

Full text of DOI:10.1134/S1070428011050204

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2011, Vol. 47, No. 5, pp. 780−782. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © L.I. Goryunov, J. Grobe, V.D. Shteingarts, R. Mews, 2011, published in Zhurnal Organicheskoi Khimii, 2011, Vol. 47, No. 5, pp. 773−775.
SHORT
COMMUNICATIONS
Synthesis of (2-X,3-Y-Phenyl)dimethylphosphanes
(
X, Y = Me P, H; Me P, F; Br, F)
2 2
and Their Complexes with PdCl2
a
b
a
c
L. I. Goryunov , J. Grobe , V. D. Shteingarts , and R. Mews
aVorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch,
Russian Academy of Sciences, Novosibirsk, 630090 Russia
e-mail: shtein@nioch.nsc.ru
b
Institut fur Anorganische und Analytische Chemie der Westfalischen Wilhelms-Universitat,
Corrensstraβe 28/30, D-48149 Munster (Germany)
e-mail: grobe@uni-muenster.de.
Institut fur Anorganische und Physikalische Chemie, Universitat Bremen, Germany
c
Received December 20, 2010
DOI: 10.1134/S1070428011050204
Earlier the trimethylsilyldimethylphosphane Me P-
sodium salts with methyl iodide [7] in 11 and 68% yield
respectively.
2
SiMe (I) was utilized for the substitution of fluorine atom
3
with PMe groups in polyfluoroarenes C F X (X = H, F, Cl,
2
6
5
Phosphane IV obtained formerly by phosphanede-
CF , etc.) and pentafluoropyridine [1, 2], and also in 1,2,3-
3
bromination of 2,6-F C H Br with lithium dimethyl-
2
6
3
and 1,3,5-trifluoro-, 1,2- and 1,3-difluorobenzenes [3, 4].
In this study the reagent was applied to the preparation
of benzene-1,2-diylbis(dimethylphosphane) (II) and its new
analog, 3-fluorobenzene-1,2-diylbis(dimethylphosphane)
phosphide (V) [8] reacted with phosphane I under milder
conditions affording in 96% yield diphosphane III that
was isolated in 57% yield (path a, Scheme 2).
Phosphane I in contrast to phosphide V reacts with
(III), chelating ligands for transition metal complexes as
2
,6-F C H Br to give 92% of (2-bromo-3-fluorophenyl)
2 6 3
had been described for phosphane II [5, 6].
dimethylphosphane (VI) and 7% of phosphane IV
Scheme 2, path b). The main product was isolated in
2% yield. The discovered difference in the results of the
reaction between 2,6-F C H Br and reagents I and V is
The reaction of ortho-difluorobenzene with exess
phosphane I at relatively high temperature led to the
(
6
1
9
31
formation (in keeping with the data of F and P NMR
2
6
3
spectra) a mixture of dimethyl(2-fluorophenyl)phosphane
probably due to the difference in the mechanism of reac-
(
(
32%) [4] and diphosphane II (68%) isolated in 60% yield
Scheme 1). Lately diphosphane II was synthesized from
tions involving nucleophiles I and V: With Me PLi this
2
is the mechanism SRN1 initiated by the electron transfer
from the nucleophile to the substrate (cf. [8]), and in the
process with Me PSiMe it is synchronic mechanism A D
dimethyl-(2-chlorophenyl)phosphane by metallation with
lithium followed by the treatment with dimethylchlorophos-
phane [5] of by alkylation of 1,2-diphosphanobenzene
2
3
N N
apparently observed in its reactions with di- and trifluoro-
benzenes [4]. In this respect it is illustrative that the ratio
Scheme 1.
(VI)–(IV) equal 13:1 indicates a weaker element-effect
compared to reactions S Ar: In the products of reaction
N
between bromofluorobenzenes with sodium methylate in
–
a mixture DMSO–MeOH the Br ions have not been found
even in traces [9]. Probably the relatively low selectivity
with respect to the nature of the substituted halogen is
characteristic of the A D mechanism combining in a cer-
N
N
7
80

SYNTHESIS OF (2-X,3-Y-PHENYL)DIMETHYLPHOSPHANES
781
Scheme 2.
Scheme 3.
R = H (II, VII), F (III, VIII).
tain way the properties of the mechanisms S Ar and S 2.
a mixture of cis- and trans-isomers (cf. [4]).
N
N
Benzene-1,2-diylbis(dimethylphosphane) (II) was
obtained from 0.057 g (0.5 mmol) of 1,2-difluoroben-
We prepared from phosphanes II, III, and VI new pal-
ladium complexes: [benzene-1,2-diylbis(dimethylphos-
phane)]palladium(II) chloride (VII), [3-fluorobenzene- zene and 0.148 g (1.1 mmol) of phosphane I in 0.5 ml of
,2-diylbis(dimethylphosphane)]palladium(II) chloride
C H in an evacuated ampule under conditions indicated
VIII), and bis[(2-bromo-3-fluorophenyl)dimethylphos-
1
6
6
(
in Scheme 1. The volatile components were distilled off
in a vacuum (0.08 mm Hg) at 20°C, from the residue by
distillation under the same pressure at heating the bath
to 100°C diphosphane II was isolated. Yield 0.061 g
(60%), colorless fluid. H and P{ H} NMR spectra are
in agreement with those published in [7].
phane)]palladium(II) chloride (IX) in 71–93% yield under
the formerly described conditions [4] (Scheme 3).
The composition and the structure of first obtained
1
19
1
31
1
compounds III, VI–IX were proved using H, F, and
3
1
P NMR spectra, for complexes, the data of high reso-
lution mass spectrometry and elemental analyses. NMR
spectra of phosphanes III and VI are in agreement with
described spectra of their dimethyl- [7, 8] and diphe-
nylphosphanyl [10] analogs. In the NMR spectra of the
Compounds III and VI were similarly obtained.
3
-Fluorobenzene-1,2-diylbis(dimethylphosphane)
(
III) was obtained from 0.056 g (0.32 mmol) of phos-
phane VI and 0.052 g (0.38 mmol) of phosphane I under
the conditions indicated in Scheme 2. Yield 0.039 g
complex VIII solution in DMSO-d alongside the peaks
6
corresponding to proper structure VIII (Scheme 3) sig-
nals are present belonging evidently to the oligomeric
form of this complex (content in the mixture ~15%).
It is analogous to the previously described fact for
poly(diphenylphosphanyl)benzene complexes of PdCl2
1
(
57%), colorless fluid. H NMR spectrum (C D ), δ,
6
6
2
ppm: 1.14 d (6H, CH , J 4.1 Hz), 1.34 d (6H, CH3,
3
PH
2JPH 4.1 Hz), 6.50–7.20 (3H, CH). 19F NMR spectrum,
31
1
δ, ppm: –104.6 br.s. P{ H} NMR spectrum, δ, ppm:
2
4
3
1
and PtCl [11]. Complex IX in the same solvent exists as
–47.3 d.d (C P, JPF 4.2, JPP 165.5 Hz), –52.2 d.d (C P,
2
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 5 2011

7
82
3JPF 9.3, 3JPP 165.5 Hz).
2-Bromo-3-fluorophenyl)dimethylphosphane (VI)
GORYUNOV et al.
17%), 7.60 br.s (cis, 83%). Found, %: C 30.35; H 2.80.
C H Br Cl F P Pd. Calculated, %: C 29.68; H 2.80.
(
16 18
1
2
2 2 2
was obtained from 0.239 g (1.2 mmol) of 2,6-F C H Br
H (200.13 MHz, internal references residual undeu-
2
6
3
1
9
and 0.107 g (0.8 mmol) phosphane I under the conditions
indicated in Scheme 2. The volatile components were
distilled off in a vacuum (0.08 mm Hg) at 20°C, from
the residue by double distillation under the same pressure
terated benzene or DMSO), F (188.31 MHz, external
reference CCl F), and P(81.02 MHz, external reference
31
3
85% H PO ) were registered on a spectrometer Bruker
3
4
AC200. Mass of molecular ions was determined on
a high-resolution mass spectrometer Thermo Scientific
DFS (70 eV). The preparation of Me SiPMe (I) and its
at heating to 150°C phosphane VI was isolated. Yield
1
0
.116 g (62%), colorless fluid. H NMR spectrum (C D ),
6
6
3
2
2
δ, ppm: 0.97 d (6H, CH , J 4.5 Hz), 6.50–6.80 m (3H,
reactions with haloarenes were performed as previously
described [1−4, 8].
3
PH
CH). 19F NMR spectrum, δ, ppm: –105.9 m. P{ H}
31
1
4
NMR spectrum, δ, ppm: –40.8 d ( J 9.2 Hz).
PF
ACKNOWLEDGMENTS
[
Benzene-1,2-diylbis(dimethylphosphane)]
palladium(II) chloride (VII). A solution of 0.060 g
The study was carried out under the financial support
of the Foundation Deutsche Forschungsgemeinschaft
DFG) and the Russian Foundation for Basic Research
grant no. 09-03-00248a).
(0.3 mmol) of diphosphane II and 0.116 g (0.3 mmol) of
(
PhCN) PdCl in 1 ml of CH Cl was stirred under an
2
2
2
2
(
(
argon atmosphere in conditions indicated in Scheme 3.
The precipitate was filtered off, washed with CH Cl
2
2
(
2 ml), and dried in a vacuum (0.08 mm Hg) at 20°C.
1
REFERENCES
Yield 0.086 g (77%), yellow crystals. H NMR spectrum
(
8
DMSO-d ), δ, ppm: 2.11 s (12H, CH ), 7.90 m (2H, CH),
6 3
31
1
1. Goryunov, L.I., Grobe, J., Shteingarts, V.D., Krebs, B.,
Linde-mann, A., Wurthwein, E.-U., and Muck-
Lichtenfeld, C., Chem. Eur. J., 2000, vol. 6, p. 4612.
.30 m (2H, CH). P{ H} NMR spectrum, δ, ppm:37.5 s.
–
+
35
104
Found [M–Cl ] 336.945. C H ClP2 Pd. Calculated
10
16
–
[
M–Cl ] 336.945.
Compounds III and IX were similarly obtained.
3-Fluorobenzene-1,2-diylbis(dimethylphosphane)]-
palladium(II) chloride (VIII) was obtained from 0.039 g
0.18 mmol)of diphosphane III and 0.069 g (0.18 mmol)
of (PhCN) PdCl . Yield 0.051 g (71%), light-brown
2
. Goryunov, L.I., Shteingarts, V.D., Grobe, J., Krebs, B.,
and Triller, M.U., Z. Anorg. Allg. Chem., 2002, vol. 628,
p. 1770.
[
3
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(
4
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Mews, R., Lork, E., and Wurthwein, E.-U., Eur. J. Org.
Chem., 2010, vol. 6, p. 1111.
2
2
1
crystals. H NMR spectrum (DMSO-d ), δ, ppm: 2.13 m
6
(6H, CH ), 2.22 m (6H, CH ), 7.70 m (1H, CH), 8.0 m
3 3
5
6
. Hart, F.A., J. Chem. Soc., 1960, p. 3324.
19
(1H, CH), 8.20 m (1H, CH). F NMR spectrum, δ, ppm:
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J. Chem. Soc., Dalton, Trans., 1983, p. 133; Champ-
ness, N.R., Levason, W., Preece, S.R., Webster, M., and
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and Wurthwein, E.-U., Zh. Org. Khim., 2009, vol. 45,
p. 1860.
31
1
1
–
102.0 m. P{ H} NMR spectrum, δ, ppm: 40.4 m (C P,
–
2
+
35
105
C P). Found [M–Cl ] 355.936. C H ClFP2 Pd.
Calculated [M–Cl ] 355.937.
1
0
15
–
7
8
Bis[(2-bromo-3-fluorophenyl)dimethylphos-
phane)]-palladium(II) chloride (IX) was obtained
from 0.116 g (0.49 mmol) of phosphane VI and 0.095 g
(
0.247 mmol) of (PhCN) PdCl . Yield 0.148 g (93%),
2 2
1
light-yellow crystals, mp 197–202°C. H NMR spec-
trum (DMSO-d ), δ, ppm: 1.75 t (6H, CH , J
4
9
. Bolton, R. and Sandall, J. P. B., J. Fluorine, Chem., 1982,
vol. 21, p. 459.
2
≈
6
3
PH
2
JPH ≈ 3.5 Hz, trans), 1.82 d (6H, CH , J 10.6 Hz,
3
PH
10. McFarlane, H.C.E. and McFarlane, W., Polyhedron,
1988, vol. 7, p. 1875.
11. McFarlane, H.C.E. and McFarlane, W., Polyhedron,
1999, vol. 18, p. 2117.
cis), 7.28–7.42, 7.45–7.58 (CH; 3H cis and 3H trans).
19
F NMR spectrum, δ, ppm: –104.5 m (cis), –105.60 m
31
1
(trans). P{ H} NMR spectrum, δ, ppm:2.60 br.s (trans,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 5 2011