Transition metal complexes containing P(C6H5)(C6H4Cl-2)2. The effect of added Lewis bases as a probe for substitution reactions occurring in ambient temperature Suzuki couplings catalyzed by Pd/P(C6H5)(C6H4Cl-2)2

Article abstract of DOI:10.1016/S0020-1693(02)01141-6

The reactivity of the d⁸ transition metal complexes, [NiBr₂(CH₃OCH₂CH₂OCH ₃)] and MCl₂L₂ (M=Pd, Pt; L=CH₃CN; L₂=1,5-cyclooctadiene), towards P(C₆H₅)(C₆H₄Cl-2)₂ (1) was investigated. While treatment of [PdCl₂(cod)] with 2 equiv of 1 resulted in displacement of the weakly coordinating cyclooctadiene and formation of [PdCl₂(P(C₆H₅)(C₆H ₄Cl-2)₂)₂], analogous reactions with [PtCl₂(cod)] afforded the monosubstituted species [PtCl₂(cod)(P(C₆H₅)(C₆H ₄Cl-2)₂)]. The disubstituted complex [PtCl₂(P(C₆H₅)(C₆H ₄Cl-2)₂)₂] was successfully obtained by treatment of [PtCl₂(NCCH₃)₂] with 2 equiv of 1. However, attempts to react 1 with [NiBr₂(CH₃OCH₂CH₂OCH ₃)] were unsuccessful. The chlorinated triphenyl phosphine is quite labile and is readily displaced from [PdCl₂(P(C₆H₅)(C₆H ₄Cl-2)₂)₂] by various Lewis bases including nitrogen containing ligands such as 2,2′-bipyridine. The molecular structure of trans-[PdCl₂(P(C₆H₅)(C₆H ₄Cl-2)₂)₂] was determined by X-ray diffraction and represents the first molecular structure determination of a transition metal complex containing 1. This complex crystallizes in the monoclinic space group P2₁/n with a=10.3928(3) ?, b=16.0102(4) ?, c=13.1884(4) ?, β=90.714(2)°, and Z=4. Key geometric parameters include Pd-Cl(1)=2.309(1) ?, Pd-P(1)=2.334(1) ?; Pd-P(1)-C(7)=118.3(2)°, Pd-P(1)-C(1)=115.3(2)°, C(1)-C(6)-Cl(2)=120.7(4)° and Cl(1)-Pd-P(1)=85.86(4)°.

Full text of DOI:10.1016/S0020-1693(02)01141-6

Inorganica Chimica Acta 342 (2003) 236ꢂ240
/
www.elsevier.com/locate/ica
Transition metal complexes containing P(C6H5)(C6H4Cl-2)2. The
effect of added Lewis bases as a probe for substitution reactions
occurring in ambient temperature Suzuki couplings catalyzed by Pd/
P(C6H5)(C6H4Cl-2)2
Joshua J. Stone a, Robert A. Stockland, Jr. a,ꢀ, Nigam P. Rath b
a Department of Chemistry, Bucknell University, Lewisburg, PA 17837, USA
b Department of Chemistry and Biochemistry, University of Missouri at St. Louis, 8001 Natural Bridge Road, St. Louis, MO 63121, USA
Received 30 March 2002; accepted 21 May 2002
Abstract
The reactivity of the d8 transition metal complexes, [NiBr2(CH3OCH2CH2OCH3)] and MCl2L2 (Mꢁ
/
Pd, Pt; Lꢁ
/
CH3CN; L2ꢁ
/
1,5-cyclooctadiene), towards P(C6H5)(C6H4Cl-2)2 (1) was investigated. While treatment of [PdCl2(cod)] with 2 equiv of 1 resulted in
displacement of the weakly coordinating cyclooctadiene and formation of [PdCl2(P(C6H5)(C6H4Cl-2)2)2], analogous reactions with
[PtCl2(cod)] afforded the monosubstituted species [PtCl2(cod)(P(C6H5)(C6H4Cl-2)2)]. The disubstituted complex
[PtCl2(P(C6H5)(C6H4Cl-2)2)2] was successfully obtained by treatment of [PtCl2(NCCH3)2] with 2 equiv of 1. However, attempts
to react 1 with [NiBr2(CH3OCH2CH2OCH3)] were unsuccessful. The chlorinated triphenyl phosphine is quite labile and is readily
displaced from [PdCl2(P(C6H5)(C6H4Cl-2)2)2] by various Lewis bases including nitrogen containing ligands such as 2,2?-bipyridine.
The molecular structure of trans-[PdCl2(P(C6H5)(C6H4Cl-2)2)2] was determined by X-ray diffraction and represents the first
molecular structure determination of a transition metal complex containing 1. This complex crystallizes in the monoclinic space
˚
˚
˚
group P21/n with aꢁ
include PdꢀCl(1)ꢁ 2.309(1) A, Pdꢀ
120.7(4)8 and Cl(1)ꢀPdꢀP(1)ꢁ85.86(4)8.
# 2002 Elsevier Science B.V. All rights reserved.
/
10.3928(3) A, bꢁ
/
16.0102(4) A, cꢁ
/
13.1884(4) A, bꢁ
/
90.714(2)8, and Zꢁ
/
4. Key geometric parameters
˚
˚
/
/
/
P(1)ꢁ
/
2.334(1) A; Pdꢀ
/
P(1)ꢀC(7)ꢁ118.3(2)8, Pdꢀ
/
/
/
P(1)ꢀC(1)ꢁ115.3(2)8, C(1)ꢀ
/
/
/
C(6)ꢀCl(2)ꢁ
/
/
/
/
/
Keywords: Nickel; Palladium; Platinum; Phosphine; Substitution reactions
1. Introduction
arylꢂ
/
aryl exchange between PPh3 and Pdꢀ
/Ar and
homocoupling of the aryl boronic acid were suppressed
when 1 was used. To gain a greater understanding of the
interaction between this ligand and transition metals, we
have investigated the complexes formed between Group
10 metals and 1. Furthermore, we have investigated the
reaction of [PdCl2(P(C6H5)(C6H4Cl-2)2)2] with various
Lewis bases in order to study the coordinating ability of
1.
Recently we observed that the chlorinated triphenyl-
phosphine, P(C6H5)(C6H4Cl-2)2 (1), is superior to PPh3
when used as a supporting ligand in the palladium
mediated Suzuki coupling of aryl bromides and chlor-
ides with aryl boronic acids (Eq. (1)) [1]. Aryl bromides
are successfully coupled at room temperature, while aryl
chlorides required slight heating. Secondary reactions
that plague Pd/PPh3 catalyzed Suzuki couplings such as
ꢀ Corresponding author. Tel.: ꢃ
1739
E-mail address: rstockla@bucknell.edu (R.A. Stockland, Jr.).
/
1-570-577 1665; fax: ꢃ1-570-577
/
ð1Þ
0020-1693/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 0 - 1 6 9 3 ( 0 2 ) 0 1 1 4 1 - 6

J.J. Stone et al. / Inorganica Chimica Acta 342 (2003) 236ꢂ
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237
2. Experimental
7.78 (broad m, 9H, Arꢀ
6.65ꢂ6.68 (m, 2H, ArꢀH), 5.05 (m, 4H, ꢁ
2.10ꢂ2.16 (m, 8H, ꢀCH2ꢀ
), 31P{1H} NMR (CDCl3,
25 8C): d 19.2 (br s, JPtP nr).
/
H). 7.08ꢂ
/
7.13 (m, 2H, Arꢀ
/
H),
/
/
/
CHCH2ꢀ
/),
2.1. General considerations
/
/
/
1
ꢁ
/
All reactions were performed under a nitrogen atmo-
sphere on a vacuum line or in a nitrogen-filled drybox.
2.2.3. Synthesis of [PtCl2(P(C6H5)(C6H4Cl-2)2)2] (4)
A flask was charged with 1 (95 mg, 0.2 mmol),
[PtCl2(NCCH3)2] (50 mg, 0.14 mmol), and THF (10
ml). This solution was refluxed for 24 h during which
time a fine precipitate formed. After filtration a yellow
powder was obtained (67.8 mg, 52%). Anal. Calc. for
THF was distilled from sodiumꢂbenzophenone. Diethyl
/
ether was purified using a Grubbs-type solvent purifica-
tion system. Dichloromethane was dried over CaH2 and
distilled. Nitrogen was purified by passage through
purification columns (oxygen and moisture) from
Chromatography Research Supplies. [PdCl2(cod)]
C36H26Cl6P2Pt: C, 46.58; H, 2.82. Found: C, 46.19; H
1
(codꢁ/1,5-cyclooctadiene) [2], [PdCl2(NCCH3)2] [3]
2.93%. H NMR (CDCl3, 25 8C): d 7.22ꢂ
/
7.45 (broad,
H), 6.66ꢂ6.69
H). 31P{1H} NMR (CDCl3, 25 8C): d
2832).
and [PtCl2(NCCH3)2] [4] were prepared as described
previously. P(C6H5)(C6H4Cl-2)2 (1) was prepared from
2-bromochlorobenzene in a manner similar to that
described in the literature [5]. [PtCl2(cod)] and
m, 18H, Arꢀ
/
H), 7.11ꢂ
/
7.13 (m, 4H, Arꢀ
/
/
(m, 4H, Arꢀ
/
1
19.14 (s, JPtP
ꢁ
/
[NiBr2(DME)] (DMEꢁ
/
CH3OCH2CH2OCH3), 2,2?-bi-
2.2.4. Reaction of [NiBr2(DME)] with 1
pyridine, 1,10-phenanthroline, and 2,9-dimethyl-1,10-
phenanthroline were obtained from Aldrich and used
as received. Elemental analyses were performed by
A flask was charged with [NiBr2(DME)] (50 mg, 0.162
mmol), 1 (107.3 mg, 0.325 mmol), and THF (10 ml). The
reaction was refluxed for 24 h. Upon removing the
solvent, a green solid was obtained. Analysis of the H
and 31P NMR spectra of the material revealed that no
uptake of 1 had occurred.
1
1
Midwest Microlabs. H (300 MHz) and 31P (121 MHz)
NMR spectra were taken using a Bruker ARX-300
instrument and referenced to Me4Si (0 ppm) and H3PO4
(85% aq. solution, 0 ppm), respectively. Quantitative
31P{1H} NMR spectra were obtained by turning off the
decoupler during the pulse and delay and setting d1 to
30 s. Coupling constants are in given in Hertz.
2.2.5. Treatment of 2 with Lewis bases
An NMR tube was charged with [PdCl2(cod)] (3 mg,
10 mmol), 1 (6.9 mg, 20 mmol), P(O)Ph3 (2.9 mg, 10.4
mmol; internal standard), Lewis base (20.8 mmol for
monodentate ligands; 10.4 mmol for bidentate ligands),
and CDCl3 (0.5 ml). The sample was heated to 90 8C
for 10 min in the sealed NMR tube. Due to the
insolubility of many of the products, the progress of
the reaction was monitored by the integration of the
internal standard P(O)Ph3 versus free 1. The results of
these experiments are summarized in Tables 3 and 4.
2.2. Reaction of MX2L2 with 1
2.2.1. Synthesis of trans-[PdCl2(P(C6H5)(C6H4Cl-
2)2)2] (2)
A flask was charged with [PdCl2(NCCH3)2] (100 mg,
0.39 mmol), 1 (260 mg, 0.79 mmol), CH2Cl2 (15 ml). The
reaction was stirred at 25 8C, and a cloudy yellowꢂ
/
orange solution was evident after 30 min. After 24 h a
fine yellow powder was obtained. After filtration and
washing with diethyl ether, the residue was dried under
vacuum to afford 300 mg (93%) of 2. Anal. Calc. for
2.2.6. Molecular structure determination of 2×
/
2CDCl3
A crystal suitable for X-ray diffraction studies was
grown by slow evaporation of a CDCl3 solution. The
data collection was performed using a Bruker SMART
C36H26Cl6P2Pd: C, 51.50; H, 3.12. Found: C, 52.20; H,
1
˚
diffractometer (Mo radiation, 0.71073 A) equipped with
3.68%. H NMR (CDCl3, 25 8C): d 7.10ꢂ
/
7.78 (broad
H). 31P{1H}
m, 22H, Arꢀ
/
H), 6.68ꢂ
/
6.70 (m, 4H, Arꢀ
/
a CCD detector at 218 K Preliminary cell determination
was done using a set of 45 narrow frames (0.38, 15 s
exposure). The data sets consisted of 4790 independent
reflections. Crystal data and structure refinement para-
meters are listed in Table 1. Structure solution and
refinement were carried out using the SHELXTL-PLUS
NMR (CDCl3, 25 8C): d 21.6. Similar results were
obtained using [PdCl2(cod)] (100 mg, 0.350 mmol) and 1
(232 mg, 0.700 mmol). A yellow solid was obtained from
this reaction (280 mg, 96%).
2.2.2. Synthesis of [PtCl2(cod)(P(C6H5)(C6H4Cl-
2)2)] (3)
A flask was charged with [PtCl2(cod)] (50.0 mg, 0.134
mmol), 1 (88.5 mg, 0.268 mmol), and THF (10 ml). The
reaction was refluxed for 24 h. After filtration and
drying under vacuum, a yellow solid was obtained.
software package [6]. The Cꢀ
/
Cl bond distances were
restrained to be within 0.05 deviation, while the thermal
parameters of the chlorines were restrained to be similar.
Due to partially twinned crystals, it was not possible to
obtain a reasonable solution from SMART. The triclinic
cell suggested by SMART resulted in extremely poor data
reduction parameters and no chemically reasonable
solution could be obtained based on this cell. Therefore,
Anal. Calc. for C26H25Cl4PPt: C, 44.27; H, 3.54. Found:
1
C, 44.30; H, 3.68%. H NMR (CDCl3, 25 8C): d 7.22ꢂ
/

238
J.J. Stone et al. / Inorganica Chimica Acta 342 (2003) 236ꢂ240
/
Table 1
Crystal data and structure refinement for 2×2CDCl3
Empirical formula
Formula weight (g molꢄ1
Crystal system
Pd0.5PCl6H13DC19
540.17
)
monoclinic
P21/n
Space group
˚
a (A)
˚
10.3928(3)
16.0102(4)
13.1884(4)
90.714(2)
2194.3(1)
4
b (A)
˚
c (A)
b (8)
3
V (A )
˚
Z
Dcalc (mg mꢄ3
)
1.632
1.255
Absorption coefficient (mmꢄ1
F(000)
Crystal size (mm)
)
1072
0.36ꢅ0.33ꢅ0.28
Fig. 1. Molecular structure (ORTEP) of 2×2CDCl3. Thermal ellipsoids
/
shown at 50% probability. The solvent of crystallization (CDCl3) has
been omitted for clarity.
b Range for data collection (8)
Reflections collected
2.00ꢂ
29786
4790 (0.041)
/
27.00
Independent reflections (Rint
Completeness to uꢁ278
Max/min transmission
Refinement method
)
selected bond distances and angles are listed in Table
2. The molecule exhibits crystallographically imposed
99.70%
0.7201/0.6607
full-matrix least-squares on F2
4790/21/269
1.302
inversion symmetry about the Pd center. The Pdꢀ
/
P(1)
bond distance was determined to be 2.334(1) A, while
the PdꢀCl(1) bond distance was measured to be 2.309(1)
A. Both of these bond distances are within the normal
range for such complexes [7]. The bond angles of Pdꢀ
P(1)ꢀC(1), PdꢀP(1)ꢀC(7) and PdꢀP(1)ꢀC(13) were all
found to be within normal ranges as well. The angle
P(1) was found to be 94.14(4)8 while
Data/restraints/parameters
Goodness-of-it on F2
˚
/
Final R indices [I ꢀ2s(I)]
R indices (all data)
R1ꢁ0.0646, wR2ꢁ0.1165
R1ꢁ0.0740, wR2ꢁ0.1197
0.625/ꢄ0.693
˚
ꢄ3
˚
Drmax/Drmin, (e A
)
/
/
/
/
/
/
between Cl(1)ꢀ
/
Pdꢀ
/
G
EMINI (Bruker-AXS, 2000) program was used to find
the complementary angle was 85.86(4)8. The compres-
sion of the bond angle is attributed to a steric interaction
out all possible cell choices of which a monoclinic cell
was chosen to be the correct cell choice for this
compound. The structure was solved and refined in
the monoclinic space group P21/n.
The compound crystallizes with a molecule of CDCl3
as solvent of crystallization. The solvent molecule is
disordered around the C atom. The disorder was
resolved with two sets of Cl atoms in 48:52% ratio.
between chlorines on palladium and the Arꢀ
/Cl groups.
While treatment of [PdCl2(cod)] with 2 equiv. of 1
rapidly formed 2, analogous reactions with [PtCl2(cod)]
did not form [PtCl2(P(C6H5)(C6H4Cl-2)2)2]. Monitoring
the reaction by 1H NMR spectroscopy (CDCl3) revealed
that free cyclooctadiene was not produced upon addi-
1
tion of 2 equiv. of 1. The H NMR spectrum of the
reaction contained peaks at d 5.05 and 2.10ꢂ2.16 ppm
/
(free cyclooctadiene d 5.52 and 2.31 ppm), suggesting
incomplete displacement of the cyclooctadiene and
formation of [PtCl2(cod)(P(C6H5)(C6H4Cl-2)2)] (3, Eq.
(2)). The 31P{1H} NMR spectrum contained peaks in a
3. Results and discussion
3.1. Treatment of L2MCl2 with P(C6H5)(C6H4Cl-2)2
Treatment of [PdCl2(cod)] or [PdCl2(CH3CN)2] with 2
equiv. of 1 resulted in the displacement of the weakly
coordinating cyclooctadiene or acetonitrile and forma-
tion of trans-[PdCl2(P(C6H5)(C6H4Cl-2)2)2] (2). This
reaction was complete within seconds at room tempera-
ture and prolonged stirring resulted in the formation of
a fine yellow powder. Complex 2 was quite stable to air
and moisture, but exhibited poor solubility in most
common organic solvents. The 31P{1H} NMR spectrum
(CDCl3, 25 8C) of 2 contained a singlet, consistent with
rapid rotamer interconversion.
Table 2
˚
Selected bond lengths (A) and angles (8) for 2×2CDCl3
Bond lengths
PdꢀCl(1)
PdꢀP(1)
P(1)ꢀC(1)
P(1)ꢀC(7)
2.309(1)
2.334(1)
1.818(5)
1.830(4)
Bond angles
PdꢀP(1)ꢀC(1)
PdꢀP(1)ꢀC(7)
PdꢀP(1)ꢀC(13)
Cl(1)ꢀPd(1)ꢀP(1)
Cl(1)?ꢀPd(1)ꢀP(1)
115.3(2)
118.5(2)
110.5(1)
85.86(4)
94.14(4)
Single crystals of 2×/2CDCl3 were grown by slow
evaporation of CDCl3 solution. The molecular structure
was determined by X-ray diffraction (Fig. 1) and

J.J. Stone et al. / Inorganica Chimica Acta 342 (2003) 236ꢂ
/240
239
1:1 ratio at d 19.1 and ꢄ
analysis was also consistent with this.
/
16.5 (free 1). The elemental
Table 3
Treatment of 2 with phosphine ligands
[PtCl2(cod)]ꢃ2 equiv: 1
0 [PtCl2(cod)(P(C6H5)(C6H4Cl2)2)]ꢃ1 equiv: 1 (2)
a
Although 1 was unsuccessful in completely displacing
cyclooctadiene from [PtCl2(cod)], treatment of trans-
PR3
% conversion
b
1
2
3
4
5
1,2-bis(diphenylphosphino)ethane
triphenyl phosphine
97
98
98
97
95
[PtCl2(NCCH3)2] with
2
equiv. of
1
afforded
[PtCl2(P(C6H5)(C6H4Cl-2)2)2]. The 31P{1H} NMR spec-
trum of the reaction mixture revealed the presence of
two peaks (d 19.14 and 26.46 ppm) during the early
stages of the reaction. This observation was consistent
with the initial formation of both cis and the trans
isomers (4a, 4b) of [PtCl2(P(C6H5)(C6H4Cl-2)2)]. Upon
standing, the conversion to a single product was
complete after 24 h (Scheme 1). This species exhibited
a peak at d 29.1 ppm in the 31P NMR spectrum
(DMSO-d6), and was assigned to 4b.
tris(4-fluorophenyl)phosphine
tris(4-chlorophenyl)phosphine
tris(2,4,6-trimethoxyphenyl)phosphine
a
CDCl3 solutions at 90 8C for 1 h in a sealed NMR tube using
P(O)Ph3 as an internal standard.
b
1 equivalent of 1,2-bis(diphenylphosphino) ethane was used.
and 4. In these cases, triarylphosphines containing the
halogen in the fourth-position completely displaced 1
from 2. Since all of the phosphine donors investigated
were successful, we examined nitrogen-based ligands
(Table 4). Treatment of a solution (CDCl3) of 2 with
nitrogen donors such as 2,2?-bipyridine and 1,10-phe-
nanthroline completely displaced 1 from 2. Only the
sterically hindered a-diimine and 2,9-dimethyl-1,10-
phenanthroline were unsuccessful in this reaction. These
results suggested that displacement of 1 from palladium
by pyridyl containing aryl halides in ambient tempera-
ture Suzuki couplings of these substrates with aryl
boronic acids could occur in significant amounts.
Substitution reactions of four-coordinate square-pla-
nar complexes have been studied extensively [10]. These
reactions proceed by associative attack of an incoming
ligand to afford a square-pyramidal intermediate fol-
lowed by rearrangement to a trigonal-bipyramidal
intermediate. Reversal of this process accompanied by
loss of the leaving ligand generates the new four-
coordinate square-planar complex. For Ni(II) it is
believed that the mechanism proceeds via a tetrahedral
intermediate [11]. These processes are repeated twice
when disubstitution occurs.
Treatment of NiCl2×/6H2O in boiling propanol with
PPh3 is a successful method for the preparation of
[NiCl2(PPh3)2] [8]. However, analogous reactions car-
ried out using 1 were unsuccessful in generating
[NiCl2(P(C6H5)(C6H4Cl-2)2)]. Upon standing, these so-
lutions afforded crystals of 1. Since the treatment of
[NiBr2(DME)] (DMEꢁCH3OCH2CH2OCH3) with
/
various Lewis bases has been shown to be successful in
displacing the DME [9], 2 equiv. of 1 was added to
solutions (CDCl3) of [NiBr2(DME)]. Upon addition of
1, free DME was not observed in the 1H NMR
spectrum. Heating this solution (70 8C, 24 h) was also
unsuccessful in displacing the DME.
3.2. Addition of Lewis bases to 2
The inability of 1 to displace cyclooctadiene from
[PtCl2(cod)] or DME from [NiBr2(DME)] prompted us
to investigate the relative lability of 1 from Group 10
metal centers. Additionally, the ease of displacement of
1 from palladium is a critical concern in the Suzuki
coupling of aryl halides with aryl boronic acids cata-
lyzed by Pd/1. These reactions were carried out by the
addition of the Lewis base to a solution (CDCl3) of 2.
Due to the low solubility of 2, it was prepared in situ
(CDCl3) from [PdCl2(cod)] and 2 equiv. of 1. The results
of this study are listed in Table 3. In all cases, a
monodentate or bidentate phosphine donor completely
displaced 1 from 2. Of particular interest are entries 3
Table 4
Treatment of 2 with nitrogen ligands
a
NS
N
% conversion
1
2
3
4
5
2,2-bipyridine
4,4-dimethyl-2,2-bipridine
1,10-phenanthroline
{(C6H3 iPr2-2,6)NꢁC(Me)}2
2,9-dimethyl-1,10-phenanthroline
99
94
97
0
0
a
CDCl3 solutions at 90 8C for 1 h in a sealed NMR tube with
P(O)Ph3 as an internal standard.
Scheme 1.

240
J.J. Stone et al. / Inorganica Chimica Acta 342 (2003) 236ꢂ240
/
4. Summary
References
Upon reacting our ligand with each of the three d8
metals under investigation it was determined that
substitution of the acetonitrile or cyclooctadiene ligands
on the Pd complex occurred with relative ease, leading
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[3] L. Hegedus, in: M. Schlosser (Ed.), Organometallics in Synthesis,
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to
2 as the sole product. Substitution of the
[4] (a) F.P. Fanizzi, F.P. Intini, L. Maresca, G. Natile, J. Chem. Soc.,
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[PtCl2(NCCH3)2] complex resulted in a mixture of cis
and trans isomers, while treatment of [PtCl2(cod)] with 1
afforded the monosubstituted species 3. Compound 1
was insufficiently basic to displace DME from
[NiBr2(DME)], even under rigorous conditions. The
displacement of 1 from 2 by added Lewis bases was
successful for numerous phosphorus and nitrogen based
ligands. The results of this investigation suggest that
displacement of 1 from palladium could occur in
significant amounts in the ambient temperature Suzuki
coupling of heteroatom containing aryl halides with aryl
boronic acids catalyzed by Pd/1.
(b) D. Fraccarollo, R. Bertani, M. Mozzon, Inorg. Chim. Acta
201 (1992) 15.
[5] (a) The procedure followed was that of Davis and Mann. M.
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(1985) 145;
(c) M.C.J.M. Van Hooijdonk, G. Gerritsen, L. Brandsma,
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[6] G.M. Sheldrick, Bruker AXS, Bruker Analytical X-ray Division,
Madison, WI, (1998).
[7] (a) N.D. Kolosova, A.N. Sobolev, T.E. Kron, E.S. Petrov, V.K.
Bel’skii, Koord. Him. 12 (1986) 393;
(b) G. Ferguson, R. McCrindle, A.J. McAlees, M. Parvez, Acta
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(c) M. Weigelt, D. Becher, E. Poetsch, C. Bruhn, D. Steinborn, Z.
Anorg. Allg. Chem. 625 (1999) 1542.
5. Supplementary material
[8] I.P. Parkin, in: J.D. Woolins (Ed.), Inorganic Experiments, VCH,
New York, 1994, p. 101.
The molecular structure information for 2 including
atomic coordinates, anisotropic displacement para-
meters, and geometrical parameters have been deposited
in the Cambridge Structural Database. Copies of the
data can be obtained free of charge on application to
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax:
[9] C.M. Killian, L.K. Johnson, M. Brookhart, Organometallics 16
(1997) 2005.
[10] A. Yamamoto, Organotransition Metal Chemistry, Wiley, New
York, 1986, pp. 199ꢂ206.
/
[11] (a) C.G. Grimes, R.G. Pearson, Inorg. Chem. 13 (1974)
970;
ꢃ
/
44-1223-336-033, e-mail: deposit@ccdc.cam.ac.uk or
(b) P. Favre, C.W. Schlaepfer, Chem. Phys. Lett. 139 (1987)
http://www.ccdc.cam.ac.uk).
250.