Palladium catalysed cross-coupling of (fluoroarene)tricarbonyl-chromium(o) complexes

Article abstract of DOI:10.1039/b006576p

(Fluoroarene)tricarbonylchromium(o) complexes were found to undergo Suzuki and Stille cross-coupling reactions to form functionalised biaryl and styrene complexes in up to 87 and 52% yields, respectively. The Suzuki reactions were optimal with dipalladium tris(dibenzylideneacetone)-trimethylphosphine-caesium carbonate in DME at reflux. The Stille reactions were optimal with dipalladium tris(dibenzylideneacetone)-trimethylphosphine-caesium fluoride in DME at reflux and neither was adversely affected by a methoxy group on the complexed ring. The Suzuki reaction tolerated a chloro group on the arylboronic acid ring but not a bromo group. The Royal Society of Chemistry 2000.

Full text of DOI:10.1039/b006576p

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Palladium catalysed cross-coupling of (fluoroarene)tricarbonyl-
chromium(0) complexes
René Wilhelm and David A. Widdowson*
1
Department of Chemistry, Imperial College of Science Technology and Medicine, London,
UK SW7 2AZ. E-mail: d.widdowson@ic.ac.uk
Received (in Cambridge, UK) 11th August 2000, Accepted 29th August 2000
First published as an Advance Article on the web 31st October 2000
(Fluoroarene)tricarbonylchromium(0) complexes were found to undergo Suzuki and Stille cross-coupling reactions to
form functionalised biaryl and styrene complexes in up to 87 and 52% yields, respectively. The Suzuki reactions were
optimal with dipalladium tris(dibenzylideneacetone)–trimethylphosphine–caesium carbonate in DME at reflux. The
Stille reactions were optimal with dipalladium tris(dibenzylideneacetone)–trimethylphosphine–caesium fluoride in
DME at reflux and neither was adversely affected by a methoxy group on the complexed ring. The Suzuki reaction
tolerated a chloro group on the arylboronic acid ring but not a bromo group.
Table
1
Control experiments for Suzuki couplings of (fluoro-
benzene)tricarbonylchromium(0)
Introduction
The Suzuki and Stille reactions are the most widely used and
successful processes for the synthesis of biaryls.1,2 Although
aryl iodides, bromides and triflates are the most commonly used
halide partners in these reactions, in some remarkable recent
developments, aryl chlorides, hitherto regarded as inert to
palladium cross-coupling reactions, have been shown to be
effective participants provided there is an electron withdrawing
group on the aryl ring3 (including the η6-tricarbonylchromium
group)4 and/or a basic phosphine ligand for palladium5–10 is
present. In the latter case, it has been shown that hindered
phosphine ligands are particularly effective, even with electron
rich aryl chlorides.5,6
Added
ligand
Yield
(%)
Run
Pd
Base (equiv.)
1
2
3
4
5
6
7
8
Pd(PPh3)4
Pd2(dba)3
Pd2(dba)3
Pd2(dba)3
Pd2(dba)3
Pd2(dba)3
—
Na2CO3 (2.2)
CsF (4)
CsF (4)
CsF (4)
—
Cs2CO3 (2.2)
Cs2CO3 (2.2)
Cs2CO3 (2.2)
Tracea
PCy3
PMe3
—
PMe3
PMe3
PMe3
—
0
52
0
0b
61
0
—
0
a Toluene as solvent. b 4-Methoxyphenylboronic acid instead of phenyl-
boronic acid.
We now report11 that aryl fluorides, as their tricarbonyl-
chromium(0) complexes 1, will also undergo palladium
catalysed cross-coupling with arylboronic acids 2 (Suzuki coup-
ling, Scheme 1) and with vinyltributylstannane (Stille coupling,
see Scheme 4).
tricarbonylchromium(0) 1, R1 = H, and phenylboronic acid 2,
R2 = H, together with sodium carbonate as base, gave the
coupled complex 3, R3 = H, but only in trace amounts (Table 1,
Run 1). When the reaction was repeated with dipalladium tris-
(dibenzylideneacetone) and caesium fluoride as the base and
with tricyclohexylphosphine (Run 2; conditions reported by
Fu and Littke5), no coupled product was detectable but
dipalladium tris(dibenzylideneacetone)–trimethylphosphine, a
phosphine not previously used for this purpose (Run 3), did
produce biphenyltricarbonylchromium(0) complex in 52%
yield.
The participation of a fluoroarene, albeit as its tricarbonyl-
chromium complex, in a palladium catalysed cross-coupling is
unprecedented12 and required careful evaluation. The ready
displacement of fluoride in these complexes by other nucleo-
philes,13–16 particularly higher halides, which could then under-
go cross-coupling, required that the system be free of any
source of such nucleophiles. Thus no solvent/additive which
might release higher halide was used and initially, either high
purity (99.9%) caesium fluoride or caesium carbonate was
used as the base. In principle, fluoride should be catalytic but
attempts to demonstrate this have so far failed.
Scheme 1 Reagents and conditions: 5 mol% Pd2(dba)3, base, ligand,
DME reflux, 16 h (dba = dibenzylideneacetone).
Control experiments covering the more obvious factors were
carried out and the results are summarised in Table 1. The
ineffectiveness of the normally active tricyclohexylphosphine as
ligand (Run 2)5,17 could be a consequence of steric hindrance
between the bulky tricarbonylchromium unit and the bulky
phosphine, and trimethylphosphine, with its lower cone angle,
was used in all subsequent experiments. In the absence of any
Results and discussion
Suzuki reactions of (fluoroarene)tricarbonylchromium(0)
complexes
Initially, we used standard conditions for Suzuki coupling1 by
which tetrakis(triphenylphosphine)palladium, fluorobenzene-
3808
J. Chem. Soc., Perkin Trans. 1, 2000, 3808–3813
This journal is © The Royal Society of Chemistry 2000
DOI: 10.1039/b006576p

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phosphine, the coupling failed (Run 4). Reaction without a base
(Run 5) also failed but the use of caesium carbonate (Run 6)
increased the yield to 61%. Reactions in the presence of base
and phosphine but without palladium (Run 7) or in the absence
of palladium and phosphine (Run 8) gave no coupled product.
Run 7 suggested that the neutral phosphine was unreactive
towards the fluoro complex but to reinforce this conclusion
a direct reaction between trimethylphosphine (1 equiv.) and
fluorobenzene complex 1, R1 = H, under cross-coupling condi-
tions was attempted. The fluoro complex was recovered
unchanged in 98% yield. This precludes a process of phos-
phonium salt formation and participation of this salt in the
cross-coupling process.18,19
Scheme 3 Reagents and conditions: 5 mol% Pd2(dba)3; 2 equiv. boronic
acid 2; 2.2 equiv. Cs2CO3; 20 mol% PMe3; DME reflux 16 h.
Table 2 Suzuki couplings of (fluorobenzene)tricarbonylchromium(0)
complexes 1 (Scheme 3)
Boronic acid 2
Product 7
The presence of unchanged starting material from Run 8 also
discounted the possibility that the arylborate anion was dis-
placing the fluoride group from the complex and that the
resultant [Cr(CO)3]phenyl arylborate was the active cross-
coupling partner.
These experiments provide strong evidence for the direct
participation of the fluorobenzene complex in the coupling
process with the implication of an unprecedented oxidative
addition of the C–F bond to the palladium(0) intermediate.20
Whether this is a concerted insertion (Scheme 2: path a) or an
addition–elimination sequence (Scheme 2: path b) via an exo
Run
R2
R1
R2
Yield (%)
1
2
3
4
5
6
7
8
9
H
H
H
H
H
H
H
H
4-MeO
4-MeO
4-MeO
H
61
87
81
78
79
0a
64
76
77
74
4-MeO
4-Me
2-MeO
2-Me
4-Br
4-Cl
H
2-Me
4-Me
4-MeO
4-Me
2-MeO
2-Me
4-Br
4-Cl
H
2-Me
4-Me
10
a Polymeric products derived from boronic acid 2, R2 = Br, were
isolated.
68% yield, was chosen for further study. A solution of this
complex 1, R1 = 4-MeO, the boronic acid 2, caesium
carbonate, 5 mol% Pd2(dba)3 and 20 mol% trimethylphosphine
in deoxygenated DME was stirred under reflux for 16 h
(Scheme 4).
The yields with both the moderately hindered [Table 2, Run
9, R2 = 2-Me, (77%)] and the unhindered [Runs 8, R2 = H (76%)
and 10, R2 = 4-Me (74%)] boronic acids were comparable to
those of the parent complex 1, R1 = H (79, 61 and 81% respect-
ively) despite the expected reduction in reactivity by the
4-methoxy group.
Stille reactions of (fluorobenzene)tricarbonylchromium
complexes
The Stille reaction is generally less facile than the Suzuki
reaction23 and in line with this, aryltributylstannanes failed to
react with the complex 1, R1 = H. However, complex 1, R1 = H
was found to couple with vinyltributylstannane, using the con-
ditions established for the Suzuki reactions, to give the styrene
complex 8, R1 = H, albeit in only 5% yield after 16 h reflux. The
use of DMF at 130 ЊC or dioxane at reflux led to the decom-
plexation of the complex.
Scheme 2
addition21 of palladium to form 4 followed by fluoride loss to
produce 5 cannot be determined at this point. The insertion
product could be active in the catalytic cycle in either neutral 6
or cationic 5 form.12
With suitable conditions established, the (fluorobenzene)-
chromium complex 1, R1 = H, was coupled with a series of
electron rich arylboronic acids 2 (Scheme 3, Table 2). The con-
ditions finally developed were to stir a solution of fluoro-
benzene complex 1, R1 = H, the boronic acid 2, caesium
carbonate, 5 mol% Pd2(dba)3 and 20 mol% trimethylphosphine
in deoxygenated DME under reflux for 16 h. Normal work-up
gave the purified coupled product. Both unhindered (Table 2,
Runs 1, 2, 3) and moderately hindered (Table 2, Runs 4, 5)
boronic acids gave good yields of 7. The polymerisation of
4-bromophenylboronic acid 2, R2 = 4-Br under the reaction
conditions can be attributed to the greater reactivity of the
C–Br bond over the C–F bond. However when 4-chloro-
phenylboronic acid 2, R2 = 4-Cl, was used the coupled product
7, R2 = 4-Cl, was isolated in 64% yield, which suggests that the
reactivity of the C-F bond in the complex 2, R1 = H, is greater
than that of the C–Cl bond under these reaction conditions.
To investigate more fully the scope of this process, the more
electron rich (4-methoxyfluorobenzene)tricarbonylchromium
complex 1, R1 = 4-MeO, prepared as before22 in an improved
Scheme 4 Reagents and conditions: 5 mol% Pd2(dba)3; 2 equiv.
Bu3Sn(CH᎐CH2); 4 equiv. CsF; 20 mol% PMe3; DME reflux 16–40 h.
᎐
On the basis that an ‘ate’ complex of the stannane is the active
coupling partner,9 the caesium carbonate was replaced by
caesium fluoride and gratifyingly, after 16 h reflux, complex 8,
R1 = H, was isolated in 48% yield (Table 3, Run 1).
With Stille coupling established, a series of functionalised
complexes, 1, R1 = 2-MeO, 4-MeO, 3-Me, 4-Me, 4-CHO, was
prepared according to literature methods.22 The yields are
given in Table 3. The previously unknown complex 1, R1 =
4-CH(OCH2)2, was prepared from 2-(4-fluorophenyl)-1,3-
J. Chem. Soc., Perkin Trans. 1, 2000, 3808–3813
3809

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Table 3 Synthesis and Stille couplings of (fluoroarene)tricarbonyl-
chromium(0) complexes 1
North London and are reported as the average of two runs.
Infrared spectra were recorded on a Perkin-Elmer RX FT-IR
System. NMR spectra were performed in CDCl3 at ambient
1
Complex 1
Product 8
temperature on a JEOL GSX 270 (270 MHz H and 68 MHz
13C). Mass spectra were recorded on VG Micromass 7070E and
AutoSpec-Q spectrometers. Melting points were taken on a
Kofler hot stage apparatus and are uncorrected. In spectral
assignments, Ar refers to the complexed ring.
Run
R1
Yield (%)
R1
Yield (%)
a
a
1
2
3
4
5
6
7
8
9
H
H
48
42
40
52
52
37
0c
2-MeO
4-MeO
3-Me
2-MeO
4-MeO
3-Me
4-Me
4-CH(OCH2)2
68
a
General procedure for the synthesis of tricarbonylchromium(0)
complexes
a
4-Me
4-CH(OCH2)2
4-CHO
H
52
92b
4-CHO
Minor variants of the method of Pauson and Mahaffy were
used for the synthesis of complexes,28 by which the arene and
hexacarbonylchromium are refluxed in an ether solvent, under
an atmosphere of nitrogen, for an empirically determined
period. The variations were in the solvent or solvent mixtures
used for the complexation process and are given below as
appropriate.
a
d
13e
6e
f
4-MeO
68
a See ref. 22. b For the acid catalysed hydrolysis of 1, R1 =
4-CH(OCH2)2. c 1, R1 = 4-CHO was unstable to the reaction conditions.
f
d Product: 3, R1 = H. e From phenyltrimethylstannane. Product: 3,
R1 = 4-MeO.
ꢀ6-(4-Methoxyfluorobenzene)tricarbonylchromium(0) 1, R1 ؍
4-OMe. 4-Methoxyfluorobenzene (15 mL, 158 mmol) and
hexacarbonylchromium (14 g, 63 mmol) were refluxed for 60 h
in dibutyl ether–THF (300 mL–10 mL). FCC (eluant: 10%
ether–hexane) furnished the complex 1, R1 = 4-OMe as a bright
yellow crystalline solid (11.12 g, 42.4 mmol, 68%, lit.22 46%),
mp 69–71 ЊC (lit.22 mp 69–70 ЊC) (Found: C, 45.72; H, 2.76.
C10H7CrFO4 requires: C, 45.82; H, 2.69%). The spectral data
were consistent with literature values.31,32
dioxolane24 by refluxing the ligand in a mixture of dibutyl ether
and THF (20:1) with hexacarbonylchromium(0) for 24 h. To
further assess electronic effects in the chromium complex, the
electron deficient formyl analogue 1, R1 = CHO, was prepared
by acid (2 M sulfuric acid) catalysed hydrolysis of the dioxolane
complex 1, R1 = 4-CH(OCH2)2, in THF during 1 h at room
temperature, in 92% yield. However, this complex proved to be
too fragile and was decomposed on attempted cross-coupling
(Table 3, Run 7) as it was by simply heating it for 30 min in
refluxing DME. Using the optimised conditions, the remaining
complexes were coupled with vinyltributylstannane (as in
Scheme 4). The results are shown in Table 3, Runs 2–6.
To address again the potential of the Stille reaction in biaryl
formation, the less hindered phenyltrimethylstannane25 was
prepared from phenyllithium (iodobenzene, BuLi) and tri-
methyltin chloride in 99% yield. Coupling of this under the
above conditions with complex 1, R1 = H, and 1, R1 = 4-MeO,
did give the products 3, R = H and 3, R1 = 4-MeO but in
only 13 and 6% yield respectively (Table 3, Runs 8, 9). The
low yield compared to the vinyltributylstannane can be related
to the known lower reactivity of phenylstannanes compared
with vinylstannanes in Stille couplings.26 The use of phenyl-
ethynyltributylstannane, which is more reactive than vinyl-
stannane26 led only to partial polymerisation and residual
starting material.
ꢀ6-[4-(1,3-Dioxolan-2-yl)fluorobenzene]tricarbonyl-
chromium(0) 1, R1 ؍ 4-CH(OCH2)2. 4-(1,3-Dioxolan-2-yl)-
fluorobenzene24 (5 g, 30 mmol) and hexacarbonylchromium
(7.17 g, 32 mmol) were refluxed for 24 h in dibutyl ether–THF
(200 mL–10 mL). FCC (eluant: 40% ether–hexane) furnished
the complex 1, R1 = 4-CH(OCH2)2 as a bright yellow crystalline
solid (4.83 g, 15.74 mmol, 53%), mp 79–80 ЊC (Found: C, 47.30;
H, 2.88. C12H9CrO5F requires: C, 47.38; H, 2.98%). νmax (KBr)/
cmϪ1 3088m, 2891w, 1968vs, 1885vs, 1480m, 1227s, 1102s, 664s,
624s. δH (270 MHz) 5.71 (2 H, dd, J 2.7, 6.7 Hz, ArC(3,5)H),
5.44 (1 H, s, CH), 5.28 (2 H, t, J 4.9 Hz, ArC(2,6)H), 4.12–3.97
(4 H, s, OCH2CH2O); δC (68 MHz) 231.1 (CO), 143.4 (d, JC–F
731.7 Hz, ArC(1)-F), 101.7 (ArC(4)-C), 100.6 (CH), 91.6 (d,
JC–F 8.0 Hz, ArC(3,5)H), 77.5 (d, JC–F 21.1 Hz, ArC(2,6)H),
65.8 (OCH2CH2O). m/z (FABϩ) 304 (Mϩ, 85%) 290 (19), 248
(Mϩ Ϫ 2 × CO, 100), 220 (Mϩ Ϫ 3 × CO, 36), 167 (Mϩ Ϫ H
Cr(CO)3), 21), 152 (26), 135 (36), 120 (66), 89 (65), 77 (72),
52 (Cr, 26). Found: Mϩ 303.9848. C12H9CrO5F requires:
303.9855.
These results clearly raise intriguing mechanistic questions,
which we continue to address. The couplings demonstrate the
versatility of the (arene)tricarbonylchromium(0) complexes and
add further possibilities to the exploitation of their already
widely established role in synthesis.
ꢀ6-(4-Formylfluorobenzene)tricarbonylchromium(0) 1, R1 ؍
4-CHO. η6-[4-(1,3-Dioxolan-2-yl)fluorobenzene]tricarbonyl-
chromium(0) 1, R1 = 4-CH(OCH2)2, (1.7 g, 5.60 mmol) was dis-
solved in THF (50 mL) and 2 M sulfuric acid (10 mL) was
added and the mixture stirred for 1 h. Ether (100 mL) was
added and the aqueous layer was separated, washed with water
(25 mL) and brine (25 mL) and dried (Mg2SO4). The solvent
was removed and FCC (eluant: 40% ether–hexane) gave the
complex 1, R1 = 4-CHO as a bright orange crystalline solid
(1.34 g, 5.15 mmol, 92%), mp 71–75 ЊC (Found: C, 46.34; H,
1.74. C10H5CrO4F requires: C, 46.17; H, 1.94%); νmax (KBr)/
cmϪ1 3095w, 1985vs, 1915vs, 1884vs, 1681s, 1229s, 1197s, 665s,
613s. δH (270 MHz) 9.35 (1 H, s, CHO), 6.02 (2 H, dd, J 2.7, 6.9
Hz, ArC(3,5)H), 5.41 (2 H, dd, J 4.9, 6.43 Hz, ArC(2,6)H);
δC (68 MHz) 228.4 (CO), 185.9 (CHO), 147.5 (d, JC–F 277.6 Hz,
ArC(1)F), 92.7 (d, J 8.0 Hz, ArC(3,5)H), 91.0 (ArC(4)-CHO),
77.84 (d, J 21.1 Hz, ArC(2,6)H). m/z (FABϩ) 260 (Mϩ,
15%), 204 (Mϩ Ϫ 2 × CO, 10), 176 (Mϩ Ϫ 3 × CO, 8), 152
(28), 135 (30), 124 (Mϩ Ϫ Cr(CO)3, 35), 120 (45), 91 (65), 69
(88), 55 (100). Found: Mϩ 259.9584. C10H5CrO4F requires:
259.9577.
Experimental
Reactions carried out under nitrogen were performed using
standard vacuum line techniques.27 THF and DME were
distilled from sodium benzophenone ketyl. Dibutyl ether
was distilled from sodium. Caesium carbonate, caesium
fluoride, tris(dibenzylideneacetone)dipalladium(0), 4-methoxy-
fluorobenzene, vinyltributylstannane and the boronic acids
were obtained from commercial sources and used without
further purification. Trimethylphosphine was used as
received from the Sigma-Aldrich Company as a 1 M solution
in toluene or THF. The known, fully characterised complexes,
η6-(fluorobenzene)tricarbonylchromium(0),28,29
η6-(2-methyl-
fluorobenzene)tricarbonylchromium(0)28 and η6-(2-methoxy-
fluorobenzene)tricarbonylchromium(0)28 and the acetal 2-(4-
fluorophenyl)-1,3-dioxolane24 were prepared according to the
indicated literature procedures. Flash column chromatography
(FCC)30 was performed on Sorbisil C-60. Elemental analyses
were carried out by Mr Stephen Boyer, SACS, University of
3810
J. Chem. Soc., Perkin Trans. 1, 2000, 3808–3813

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General procedure for the coupling of (fluoroarene)chromium
complexes with arylboronic acids
m/z (EI) 320 (Mϩ, 24%), 264 (Mϩ – 2 × CO, 13), 236
(Mϩ Ϫ 2 × CO, 67), 221 (236 Ϫ Me, 81), 184 (Mϩ Ϫ Cr(CO)3,
6), 169 (221 Ϫ Cr, 8), 52 (Cr, 100). Found: Mϩ 320.0128.
C16H12CrO4 requires: 320.0141.
A solution of the (fluoroarene)tricarbonylchromium(0) com-
plex (1 equiv., 1.29 mmol), arylboronic acid (2 equiv., 2.58
mmol), caesium carbonate (2.2 equiv., 0.925 g, 2.84 mmol),
Pd2(dba)3 (5 mol%, 0.060 g, 0.06 mmol) and trimethyl-
phosphine (20 mol%, 0.26 mL, 1 M solution in toluene, 0.26
mmol) in deoxygenated DME (9 mL) was stirred under reflux
for 16 h. Ether (20 mL) was added and the solution was washed
with 10% NaOH(aq) (10 mL), water (10 mL) and brine (10 mL)
and dried over MgSO4. Concentration in vacuo followed by
column chromatography (FCC) and recrystallisation where
necessary furnished the desired complex.
ꢀ6-[(4-Methylphenyl)benzene]tricarbonylchromium(0)
7,
R1 ؍ H, R2 ؍ 4-Me. From η6-(fluorobenzene)tricarbonyl-
chromium(0) 1, R1 = H (0.300 g, 1.29 mmol) and 4-methyl-
phenylboronic acid (0.350 g, 2.58 mmol). FCC (eluant: 5%
ether–hexane) furnished the title product 7, R1 = H, R2 = 4-Me,
as a yellow crystalline solid (0.329 g, 1.08 mmol, 84%), mp 100–
104 ЊC (Found: C, 63.31; H, 3.94. C16H12CrO3 requires: C,
63.16; H, 3.98%). νmax (KBr)/cmϪ1 3088w, 1958s, 1896s, 1878s,
1458w, 1151m, 1011m, 810m, 659m, 629s, 531m. δH (270 MHz)
7.39 (2 H, d, J 8.2 Hz, Ph(2,6)H), 7.21 (2 H, d, J 7.9 Hz,
Ph(3,5)H), 5.66 (2 H, dd, J 1.0, 6.9 Hz, Ar(2,6)H), 5.48 (2 H, t,
6.7 Hz, Ar(3,5)H), 5.30 (1 H, tt, J 1.0, 6.2 Hz, Ar(4)H), 2.37
(3 H, s, Me); δC (68 MHz) 232.9 (CO), 139.3 (PhC(4)-Me),
133.6 (PhC(1)-Ar), 129.6 (PhC(3,5)H), 127.0 (PhC(2,6)H),
111.0 (ArC(1)-Ph), 92.9 (ArC(2,6)H), 91.9 (ArC(3,5)H), 91.2
(ArC(4)H), 21.2 (OMe). m/z (EI) 304 (Mϩ, 9%), 248 (Mϩ Ϫ
2 × CO, 12), 220 (Mϩ Ϫ 3 × CO, 46), 168 (Mϩ Ϫ Cr(CO)3, 8),
152 (168 Ϫ H Ϫ Me, 5), 80 (19), 52 (Cr, 100). Found: Mϩ
304.0191. C16H12CrO4 requires: 304.0192.
ꢀ6-(Phenylbenzene)tricarbonylchromium(0) 3, R1 ؍ H. From
η6-(fluorobenzene)tricarbonylchromium(0) 1, R1 = H (0.300 g,
1.29 mmol) and phenylboronic acid (0.320 g, 2.58 mmol). FCC
(eluant: 5% ether–hexane) furnished the title product 3, R1 = H,
as a yellow crystalline solid (0.230 g, 0.79 mmol, 61%), mp 84–
86 ЊC (lit.33 84–85 ЊC) (Found: C, 61.86; H, 3.61. C15H10CrO3
requires: C, 62.07; H, 3.47%). νmax (KBr)/cmϪ1 3187w, 3026w,
1976s, 1866s, 1452m, 760m, 698s, 660s, 622m, 533m. δH (270
MHz) 7.51–7.34 (5 H, m, PhH), 5.69 (2 H, dd, J 1.0, 6.7 Hz,
Ar(2,6)H), 5.49 (2 H, t, J 6.5 Hz, Ar(3,5)H), 5.34 (1 H, tt, J 1.0,
6.2 Hz, Ar(4)H); δC (68 MHz) 232.8 (CO), 136.6 (PhC(1)-Ar),
129.1 (PhC(4)H), 128.9 (PhC(3,5)H), 127.2 (PhC(2,6)H), 110.6
(ArC(1)-Ph), 92.6 (ArC(2,6)H), 92.3 (ArC(3,5)H), 91.5
(ArC(4)H). m/z (EI) 290 (Mϩ, 23%), 234 (Mϩ Ϫ 2 × CO, 21),
206 (Mϩ – 3 × CO, 79), 154 (Mϩ Ϫ Cr(CO)3, 30), 77 (Ph, 5), 52
(Cr, 100). Found: Mϩ 290.0030. C15H10CrO3 requires: 290.0035.
The spectral data were consistent with literature values.34
ꢀ6-[(2-Methylphenyl)benzene]tricarbonylchromium(0) 7, R1 ؍
H,
R2 ؍ 2-Me.
From
η6-(fluorobenzene)tricarbonyl-
chromium(0) 1, R1 = H (0.300 g, 1.29 mmol) and 2-methyl-
phenylboronic acid (0.350 g, 2.58 mmol). FCC (eluant: 5%
ether–hexane) furnished the title product 7, R1 = H, R2 = 2-Me,
as a yellow crystalline solid (0.311 g, 1.02 mmol, 79%), mp 109–
112 ЊC (Found: C, 63.30; H, 4.14. C16H12CrO3 requires: C,
63.16; H, 3.98%). νmax (KBr)/cmϪ1 2924w, 1966s, 1869vs, 1640w,
1470w, 1044w, 822m, 765m, 659m, 630s, 529m. δH (270 MHz)
7.44–7.39 (2 H, m, PhH), 7.30–7.19 (2 H, m, Ph), 5.51 (2 H, dd,
J 1.0, 6.9 Hz, Ar(2,6)H), 5.45 (1 H, tt, J 1.0, 6.2 Hz, Ar(4)H),
5.33 (2 H, t, J 6.2 Hz, Ar(3,5)H), 2.33 (3 H, s, Me); δC (68
MHz) 232.8 (CO), 136.0 (PhC(2)-Me), 135.9 (PhC(6)H),
131.6 (PhC(4)H), 130.4 (PhC(1)-Ar), 128.7 (PhC(5)H), 126.5
(PhC(3)H), 113.2 (ArC(1)-Ph), 96.7 (ArC(2,6)H), 93.5
(ArC(4)H), 90.1 (ArC(3,5)H), 20.4 (Me). m/z (EI) 304 (Mϩ,
14%), 248 (Mϩ Ϫ 2 × CO, 18), 220 (Mϩ Ϫ 3 × CO, 67), 168
(Mϩ Ϫ Cr(CO)3, 8), 152 (168 Ϫ H Ϫ Me, 9), 80 (23), 77 (Ph, 8),
52 (Cr, 100). Found: Mϩ 304.0194. C16H12CrO4 requires:
304.0192.
ꢀ6-[(4-Methoxyphenyl)benzene]tricarbonylchromium(0)
7,
R1 ؍ H, R2 ؍ 4-MeO. From η6-(fluorobenzene)tricarbonyl-
chromium(0) 1, R1 = H (0.300 g, 1.29 mmol) and 4-methoxy-
phenylboronic acid (0.392 g, 2.58 mmol). FCC (eluant: 5%
ether–hexane) furnished the title product 7, R1 = H, R2 =
4-MeO, as a yellow crystalline solid (0.360 g, 1.12 mmol, 87%),
mp 58–61 ЊC (Found: C, 59.99; H, 3.69. C16H12CrO4 requires:
C, 60.01; H, 3.78%). νmax (KBr)/cmϪ1 2968w, 2838w, 1977s,
1961s, 1887s, 1868s, 1609m, 1508m, 1454m, 1279m, 1249m,
1176m, 1020m, 840m, 819m, 661m, 629s, 535m. δH (270 MHz)
7.43 (2 H, d, J 8.9 Hz, Ph(2,6)H), 6.93 (2 H, d, J 8.9 Hz,
Ph(3,5)H), 5.64 (2 H, dd, J 1.0, 6.7 Hz, Ar(2,6)H), 5.49 (2 H, t,
J 6.4 Hz, Ar(3,5)H), 5.28 (1 H, tt, J 1.0, 6.2 Hz, Ar(4)H), 3.83
(3 H, s, OMe); δC (68 MHz) 233.0 (CO), 160.4 (PhC(4)-OMe),
128.6 (PhC(1)-Ar), 128.3 (PhC(2,6)H), 114.3 (PhC(3,5)H),
111.2 (ArC(1)-Ph), 93.2 (ArC(2,6)H), 91.6 (ArC(3,5)H), 90.9
(ArC(4)H), 55.4 (OMe). m/z (EI) 320 (Mϩ, 43%), 264
(Mϩ Ϫ 2 × CO, 39), 236 (Mϩ Ϫ 3 × CO, 93), 221 (236 Ϫ Me,
11), 205 (236 Ϫ OMe, 5), 184 (Mϩ Ϫ Cr(CO)3, 9), 169 (221 Ϫ
Cr, 4), 52 (Cr, 100). Found: Mϩ 320.0130. C16H12CrO4 requires:
320.0141.
ꢀ6-[(4-Chlorophenyl)benzene]tricarbonylchromium(0) 7, R1 ؍
H, R2 ؍ 4-Cl. From η6-(fluorobenzene)tricarbonylchromium(0)
1, R1 = H (0.300 g, 1.29 mmol) and 4-chlorophenylboronic acid
(1.5 equiv., 0.302 g, 1.94 mmol). FCC (eluant: 10% ether–
hexane) furnished the title product 7, R1 = H, R2 = 4-Cl, as a
yellow crystalline solid (0.312 g, 0.95 mmol, 74%), mp 108–
112 ЊC (Found: C, 55.66; H, 2.73. C15H9CrO3Cl requires: C,
55.49; H, 2.79%). νmax (KBr)/cmϪ1 1949s, 1869s, 805m, 658m,
630s, 536m. δH (270 MHz) 7.42 (2 H, d, J 8.7 Hz, Ph(2,6)H),
7.37 (2 H, d, J 8.7 Hz, Ph(3,5)H), 5.63 (2 H, d, J 6.2 Hz,
Ar(2,6)H), 5.48 (2 H, t, J 6.2 Hz, Ar(3,5)H), 5.34 (1 H, t, J 6.4
Hz, Ar(4)H); δC (68 MHz) 232.5 (CO), 135.2 (PhC(4)-Cl), 129.2
(PhC(3,5)H), 128.4 (PhC(1)-Ar, PhC(2,6)H), 109.1 (ArC(1)-
Ph), 92.5 (ArC(2,6)H), 91.9 (ArC(3,5)H), 91.5 (ArC(4)H). m/z
(EI) 324 (Mϩ, 100%), 268 (Mϩ Ϫ 2 × CO, 11), 240 (Mϩ Ϫ
3 × CO, 26), 188 (Mϩ Ϫ Cr(CO)3, 14), 152 (188 Ϫ Cl, 33), 80
(78), 52 (Cr, 95). Found: Mϩ 323.9650. C15H9CrO3Cl requires:
323.9645.
ꢀ6-[(2-Methoxyphenyl)benzene]tricarbonylchromium(0)
7,
R1 ؍ H, R2 ؍ 2-MeO. From η6-(fluorobenzene)tricarbonyl-
chromium(0) 1, R1 = H (0.300 g, 1.29 mmol) and 2-methoxy-
phenylboronic acid (0.392 g, 2.58 mmol). FCC (eluant: 5%
ether–hexane) furnished the title product 7, R1 = H, R2 =
2-MeO, as a yellow crystalline solid (0.320 g, 1.01 mmol, 78%),
mp 106–108 ЊC (Found: C, 60.23; H, 3.87. C16H12CrO4 requires:
C, 60.01; H, 3.78%). νmax (KBr)/cmϪ1 2937w, 1951s, 1880s,
1856vs, 1496m, 1266m, 1024m, 755m, 660s, 632s, 529m. δH (270
MHz) 7.41–7.30 (2 H, m, PhH), 7.03–6.92 (2 H, m, PhH),
5.74–5.72 (2 H, m, ArH), 5.38–5.31 (3 H, m, ArH), 3.85 (3 H,
s, OMe); δC (68 MHz) 233.2 (CO), 156.9 (PhC(2)-OMe),
131.1 (PhC(6)H), 130.2 (PhC(4)H), 125.1 (PhC(1)-Ar), 120.9
(PhC(5)H), 111.3 (PhC(3)H), 108.3 (ArC(1)-Ph), 96.3
(ArC(2,6)H), 92.5 (ArC(4)H), 91.4 (ArC(3,5)H), 55.6 (OMe).
ꢀ6-(1-Phenyl-4-methoxybenzene)tricarbonylchromium(0)
7,
R1 ؍ MeO, R2 ؍ H. From η6-(4-methoxyfluorobenzene)-
tricarbonylchromium(0) 1, R1 = 4-MeO (0.338 g, 1.29 mmol)
and phenylboronic acid (0.320 g, 2.58 mmol). FCC (eluant:
15% ether–hexane) furnished the title product 7, R1 = MeO,
J. Chem. Soc., Perkin Trans. 1, 2000, 3808–3813
3811

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R2 = H, as a yellow crystalline solid (0.312 g, 0.99 mmol, 76%),
mp 123–124 ЊC (Found: C, 60.20; H, 3.88. C16H12CrO4 requires:
C, 60.01; H, 3.78%). νmax (KBr)/cmϪ1 3097w, 1942s, 1879s,
1856vs, 1653m, 1543m, 1478m, 1260m, 1156m, 1020m, 764m,
673s, 634m, 534m. δH (270 MHz) 7.46–7.28 (5 H, m, PhH),
5.90 (2 H, d, J 6.9 Hz, Ar(2,6)H), 5.23 (2 H, d, J 6.9 Hz,
Ar(3,5)H), 3.73 (3 H, s, OMe); δC (68 MHz) 234.0 (CO), 142.7
(ArC(1)-OMe), 136.3 (PhC(1)-Ar), 128.9 (PhC(3,5)H), 128.6
(PhC(4)H), 127.1 (PhC(2,6)H), 103.9 (ArC(1)-Ph), 94.6
(ArC(2,6)H), 77.7 (ArC(3,5)H), 55.8 (OMe). m/z (EI) 320 (Mϩ,
41%), 264 (Mϩ Ϫ 2 × CO, 28), 236 (Mϩ Ϫ 3 × CO, 100), 221
(236 Ϫ Me, 8), 204 (236 Ϫ OMe Ϫ H, 3), 184 (Mϩ Ϫ Cr(CO)3,
11), 169 (221 Ϫ Cr, 7), 80 (37), 52 (Cr, 63). Found: Mϩ
320.0131. C16H12CrO4 requires: 320.0141.
ꢀ6-(Vinylbenzene)tricarbonylchromium(0) 8, R1 ؍ H. From η6-
(fluorobenzene)tricarbonylchromium(0) 1, R1 = H (0.300 g, 1.29
mmol); column chromatography (eluant: 10% ether–hexane)
furnished the title product 8, R1 = H, as a yellow crystalline solid
(0.146 g, 0.61 mmol, 48%), mp 79–80 ЊC (lit.35 78–79 ЊC)
(Found: C, 54.92; H, 3.20. C11H8CrO3 requires: C, 55.01; H,
3.36%). νmax (KBr)/cmϪ1 3080w, 1952vs, 1861vs, 1405m, 821m,
630s. δ (270 MHz) 6.26 (1 H, dd, J 10.6, 17.6 Hz, ᎐CH), 5.65
᎐
H
(1 H, d, J 17.6 Hz, trans ᎐CHH), 5.32 (1 H, d, J 10.6 Hz, cis
᎐
᎐CHH), 5.43–5.24 (5 H, m, ArH); δ (68 MHz) 232.8 (CO),
᎐
C
133.6 (CH), 116.6 (CH2), 105.6 (ArC(1)-C), 92.7 (ArC(2,6)H),
91.3 (ArC(4)H), 90.6 (ArC(3,5)H). m/z (EI) 240 (Mϩ, 44%),
217 (5), 212 (Mϩ Ϫ CO, 6), 204 (37), 184 (Mϩ Ϫ 2 × CO, 15),
156 (Mϩ Ϫ 3 × CO, 75), 128 (30), 104 (Mϩ Ϫ Cr(CO)3, 8),
77 (6), 52 (Cr, 100) Found: Mϩ 239.9875. C11H8CrO3 requires:
239.9879. The spectral data were consistent with the literature
values.35
ꢀ6-1-(2-Methylphenyl)-4-methoxybenzene]tricarbonyl-
chromium(0) 7, R1 ؍ MeO, R2 ؍ 2-Me. From η6-(4-methoxy-
fluorobenzene)tricarbonylchromium(0) 1, R1 = 4-MeO (0.338 g,
1.29 mmol) and 2-methylphenylboronic acid (0.350 g, 2.58
mmol). FCC (eluant: 15% ether–hexane) and recrystallisation
(ether–hexane) furnished the title product 7, R1 = MeO,
R2 = 2-Me, as a yellow crystalline solid (0.326 g, 0.98 mmol,
77%), mp 87–90 ЊC (Found: C, 60.88; H, 4.32. C17H14CrO4
requires: C, 61.08; H, 4.22%). νmax (KBr)/cmϪ1 3014w, 2933w,
2836w, 1959s, 1872s, 1543m, 1471m, 1249s, 1028m, 769m, 670s,
629s, 523m. δH (270 MHz) 7.34–7.16 (4 H, m, PhH), 5.64 (2 H,
d, J 6.9 Hz, Ar(2,6)H), 5.14 (2 H, d, J 6.9 Hz, Ar(3,5)H),
3.75 (3 H, s, OMe), 2.29 (3 H, s, Me); δC (68 MHz) 233.0 (CO),
143.0 (ArC(4)-OMe), 136.1 (PhC(1)-Ar), 135.7 (PhC(2)-Me),
131.9 (PhC(6)H), 130.2 (PhC(4)H), 128.6 (PhC(5)H), 126.5
(PhC(3)H), 107.3 (ArC(1)-Ph), 97.6 (ArC(2,6)H), 76.3 (ArC-
(3,5)H), 55.7 (OMe), 20.4 (Me). m/z (EI) 334 (Mϩ, 56%), 278
(Mϩ Ϫ 2 × CO, 8), 250 (Mϩ Ϫ 3 × CO, 34), 198 (Mϩ Ϫ
Cr(CO)3, 2), 52 (Cr, 100). Found: Mϩ 334.0299. C17H14CrO4
requires: 334.0297.
ꢀ6-[(4-Methoxy)vinylbenzene]tricarbonylchromium(0)
8,
R1 ؍ 4-MeO. From η6-(4-methoxyfluorobenzene)tricarbonyl-
chromium(0) 1, R1 = 4-MeO (0.338 g, 1.29 mmol); column
chromatography (eluant: 15% ether–hexane) furnished the title
product 8, R1 = 4-MeO, as a yellow crystalline solid (0.172 g,
0.52 mmol, 40%), mp 60–61 ЊC (Found: C, 53.29; H, 3.52.
C12H10CrO4 requires: C, 53.34; H, 3.73%). νmax (KBr)/cmϪ1
1956vs, 1850vs, 1628m, 1253s, 673s. δH (270 MHz) 6.17 (1 H,
dd, J 10.9, 17.3 Hz, ᎐CH), 5.65 (2 H, d, J 6.7 Hz, Ar(2,6)H),
᎐
5.55 (1 H, d, J 17.6 Hz, trans ᎐CHH), 5.17 (1 H, d, J 11.1 Hz,
᎐
cis ᎐CHH), 5.15 (2 H, d, J 5.4 Hz, Ar(3,5)H), 3.69 (3 H, s,
᎐
OMe); δC (68 MHz) 232.9 (CO), 143.1 (ArC(4)-OMe), 132.7
(CH), 114.8 (CH2), 105.7 (ArC(1)-C), 92.6 (ArC(2,6)H), 77.9
(ArC(3,5)H), 55.8 (OMe). m/z (EI) 270 (Mϩ, 44%), 262 (13),
214 (Mϩ Ϫ 2 × CO, 9), 186 (Mϩ Ϫ 3 × CO, 46), 178 (13), 134
(Mϩ Ϫ Cr(CO)3, 8), 80 (42), 52 (Cr, 100). Found: Mϩ 269.9983.
C12H10CrO4 requires: 269.9984.
ꢀ6-[1-(4-Methylphenyl)-4-methoxybenzene]tricarbonyl-
chromium(0) 7, R1 ؍ MeO, R2 ؍ 4-Me. From η6-(4-methoxy-
fluorobenzene)tricarbonylchromium(0) 1, R1 = 4-MeO (0.338 g,
1.29 mmol) and 4-methylphenylboronic acid (0.350 g, 2.58
mmol). FCC (eluant: 15% ether–hexane) furnished the title
product 7, R1 = MeO, R2 = 4-Me, as a yellow crystalline solid
(0.319 g, 0.95 mmol, 74%), mp 126–128 ЊC (Found: C, 60.80; H,
4.29. C17H14CrO4 requires: C, 61.08; H, 4.22%). νmax (KBr)/
cmϪ1 3089w, 2935w, 2843w, 1953vs, 1858vs, 1519m, 1479m,
1438m, 1253m, 1029m, 823m, 668m, 659m, 623m, 530m.
δH (270 MHz) 7.33 (2 H, d, J 8.2 Hz, Ph(3,5)H), 7.16 (2 H, d,
J 8.2 Hz, Ph(2,6)H), 5.87 (2 H, d, J 6.9 Hz, Ar(2,6)H), 5.22
(2 H, d, J 6.9 Hz, Ar(3,5)H), 3.72 (3 H, s, OMe), 2.35 (3 H,
s, Me); δC (68 MHz) 233.1 (CO), 142.4 (ArC(4)-OMe),
138.6 (PhC(1)-Ar), 133.4 (PhC(4)-Me), 129.5 (PhC(2,6)H),
126.8 (PhC(3,5)H), 110.5 (ArC(1)-Ph), 94.4 (ArC(2,6)H), 77.8
(ArC(3,5)H), 55.8 (OMe), 21.1 (Me). m/z (EI) 334 (Mϩ,
24%), 278 (Mϩ Ϫ 2 × CO, 18), 250 (Mϩ Ϫ 3 × CO, 100), 198
(Mϩ Ϫ Cr(CO)3, 8), 80 (13), 52 (Cr, 79). Found: Mϩ 334.0296.
C17H14CrO4 requires: 334.0297.
ꢀ6-[(2-Methoxy)vinylbenzene]tricarbonylchromium(0) 8, R1 ؍
2-MeO.
From
η6-(2-methoxyfluorobenzene)tricarbonyl-
chromium(0) 1, R1 = 2-MeO (0.140 g, 0.53 mmol); column
chromatography (eluant: 15% ether–hexane) furnished the title
product 8, R1 = 2-MeO, as a yellow crystalline solid (0.061 g,
0.27 mmol, 42%), mp 78–80 ЊC (Found: C, 53.48; H, 3.96.
C12H10CrO4 requires: C, 53.34; H, 3.73%). νmax (KBr)/cmϪ1
1956vs, 1847vs, 1535m, 1247s, 672s. δH (270 MHz) 6.72 (1 H,
dd, J 11.1, 17.6 Hz, ᎐CH), 5.86 (1 H, dd, J 1.5, 6.4 Hz, Ar(6)H),
᎐
5.63 (1 H, d, J 17.6 Hz, trans ᎐CHH), 5.52 (1 H, dt, J 1.5,
᎐
6.2 Hz, Ar(4)H), 5.27 (1H, d, J 11.1 Hz, cis ᎐CHH), 5.09 (1 H,
᎐
d, J 6.9 Hz, Ar(3)H), 4.96 (1 H, t, J 6.2 Hz, Ar(5)H), 3.78 (3 H,
s, OMe); δC (68 MHz) 233.2 (CO), 141.0 (ArC(2)-O), 129.1
(CH), 116.8 (CH2), 107.8 (ArC(1)-C), 93.5 (ArC(6)H), 92.5
(ArC(4)H), 85.5 (ArC(5)H), 74.1 (ArC(3)H), 55.9 (OMe). m/z
(EI) 270 (Mϩ, 51%), 242 (Mϩ Ϫ CO, 6), 214 (Mϩ Ϫ 2 × CO,
26), 186 (Mϩ Ϫ 3 × CO, 12), 135 (Mϩ ϩ H Ϫ Cr(CO)3, 28),
120 (40), 91 (54), 55 (100). Found: Mϩ 269.9996. C12H10CrO4
requires: 269.9984. The 1H NMR was consistent with the
literature values.36
General procedure for the coupling of (fluoroarene)chromium
complexes with vinyltributylstannane
ꢀ6-[(4-Methyl)vinylbenzene]tricarbonylchromium(0) 8, R1 ؍
4-Me. From η6-(4-methylfluorobenzene)tricarbonylchrom-
ium(0) 1, R1 = 4-Me (0.317 g, 1.29 mmol); column chroma-
tography (eluant: 10% ether–hexane) furnished the title product
8, R1 = 4-Me, as a yellow crystalline solid (0.170 g, 0.67 mmol,
52%), mp 68 ЊC (Found: C, 56.94; H, 4.05. C12H10CrO3
requires: C, 56.70; H, 3.97%). νmax (KBr)/cmϪ1 3074w, 1960vs,
1856vs, 1538m, 922s, 624s. δH (270 MHz) 6.22 (1 H, dd, J 10.9,
A solution of a (fluoroarene)tricarbonylchromium(0) complex
(1 equiv., 1.29 mmol), vinyltributylstannane (2 equiv., 0.75 mL,
2.58 mmol), caesium fluoride (4 equiv., 0.780 g, 5.16 mmol),
Pd2(dba)3 (5 mol%, 0.060 g, 0.06 mmol) and trimethyl-
phosphine (20 mol%, 0.26 mL, 1 M solution in THF, 0.26
mmol) in deoxygenated DME (9 mL) was stirred under reflux
for 16–40 h. Ether (20 mL) was added and the solution
was washed with saturated KF(aq) (10 mL), water (10 mL) and
brine (10 mL) and dried over MgSO4. Concentration in vacuo
followed by flash column chromatography (FCC) and recrystal-
lisation were necessary to furnish the desired complex.
17.6 Hz, ᎐CH), 5.61 (1 H, d, J 17.3 Hz, trans ᎐CHH), 5.51 (2 H,
᎐
᎐
d, J 6.7 Hz, Ar(3,5)H), 5.24 (1 H, d, J 11.1 Hz, cis =CHH), 5.21
(2 H, d, J 7.4 Hz, Ar(2,6)H), 2.17 (3 H, s, Me); δC (68 MHz)
233.2 (CO), 133.2 (CH), 115.6 (CH2), 108.5 (ArC(4)-Me), 102.9
(ArC(1)-C), 92.8 (ArC(2,6)H), 92.1 (ArC(3,5)H), 20.5 (Me).
3812
J. Chem. Soc., Perkin Trans. 1, 2000, 3808–3813

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m/z (EI) 254 (Mϩ, 30%), 198 (Mϩ Ϫ 2 × CO, 16), 170
(Mϩ Ϫ 3 × CO, 93), 118 (Mϩ Ϫ Cr(CO)3, 6), 91 (6), 52 (100).
Found: Mϩ 254.0042. C12H10CrO3 requires: 254.0035.
R1 = MeO, as a yellow crystalline solid (0.020 g, 0.06 mmol, 6%)
with spectral data identical to those of the Suzuki reaction
product.
ꢀ6-[(3-Methyl)vinylbenzene]tricarbonylchromium(0) 8, R1 ؍
3-Me. From η6-(3-methylfluorobenzene)tricarbonylchrom-
ium(0) 1, R1 = 3-Me (0.317 g, 1.29 mmol); column chrom-
atography (eluant: 10% ether–hexane) and recrystallisation
(ether–hexane) furnished the title product 8, R1 = 3-Me, as a yel-
low crystalline solid (0.173 g, 0.67 mmol, 52%), mp 62–64 ЊC
(Found: C, 57.06; H, 3.99. C12H10CrO3 requires: C, 56.70; H,
3.97%). νmax (KBr)/cmϪ1 1948s, 1871s, 1032w, 926w, 838w,
663m, 631m, 536w. δH (270 MHz) 6.28 (1H, dd, J 10.6, 17.3 Hz,
᎐CH), 5.66 (1 H, d, J 17.6 Hz, trans ᎐CHH), 5.46 (1 H, t, J 6.4
References
1 A. Suzuki, in Metal catalysed cross coupling reactions, ed.
F. Diederich and P. J. Stang, Weinheim, 1998.
2 J. K. Stille, Pure Appl. Chem., 1985, 57, 1771.
3 K.-I. Gouda, E. Hagiwara, Y. Hatanaka and T. Hiyama, J. Org.
Chem., 1996, 61, 7232.
4 W. J. Scott, J. Chem. Soc., Chem. Commun., 1987, 1755.
5 A. F. Littke and G. C. Fu, Angew. Chem., Int. Ed., 1998, 37, 3387.
6 D. W. Old, J. P. Wolfe and S. L. Buchwald, J. Am. Chem. Soc., 1998,
120, 9722.
7 F. Firooznia, C. Gude, K. Chan and Y. Satoh, Tetrahedron Lett.,
1998, 39, 3985.
8 C. Zhang, J. Huang, M. L. Trudell and S. P. Nolan, J. Org. Chem.,
1999, 64, 3804.
9 A. F. Littke and G. C. Fu, Angew. Chem., Int. Ed., 1999, 38, 2411.
10 J. P. Wolfe and S. L. Buchwald, Angew. Chem., Int. Ed., 1999, 38,
2413.
11 D. A. Widdowson and R. Wilhelm, Chem. Commun., 1999, 2211.
12 E.-I. Negishi and F. Liu, in Metal catalysed cross coupling reactions,
ed. F. Diederich and P. J. Stang, Weinheim, 1998.
13 K. Kirschke, J. Deutsch and H. J. Niclas, Phosphorus Sulfur Silicon
Relat. Elem., 1996, 117, 293.
14 F. Rose-Munch, E. Rose, A. Semra, L. Mignon, J. Garcia-Oricain
and C. Knobler, J. Organomet. Chem., 1989, 363, 297.
15 M. F. Semmelhack, G. Hilt and J. H. Colley, Tetrahedron Lett.,
1998, 39, 7683.
᎐
᎐
Hz, Ar(5)H), 5.38 (1 H, d, J 10.9 Hz, cis ᎐CHH), 5.25 (1 H, s,
᎐
Ar(2)H), 5.23 (1 H, d, J 6.4 Hz, Ar(4)H), 5.09 (1 H, d, J 6.5 Hz,
Ar(6)H), 2.22 (3 H, s, Me); δC (68 MHz) 233.3 (CO), 133.8
(CH), 116.9 (CH2), 109.3 (ArC(3)-Me), 106.7 (ArC(1)-C), 94.1,
91.6, 91.1, 87.9 (ArCH), 20.9 (Me). m/z (EI) 254 (Mϩ, 25%),
198 (Mϩ Ϫ 2 × CO, 11), 170 (Mϩ Ϫ 3 × CO, 83), 118 (Mϩ Ϫ
Cr(CO)3, 4), 91 (5), 52 (100). Found: Mϩ 254.0028. C12H10CrO3
requires: 254.0035.
ꢀ6-[4-(1,3-Dioxolan-2-yl)vinylbenzene]tricarbonylchromium(0)
8, R1 ؍ 4-CH(OCH2)2. From η6-[4-fluoro(1,3-dioxolan-2-yl)-
benzene]tricarbonylchromium(0) 1, R1 = 4-CH(OCH2)2 (0.392
g, 1.29 mmol); column chromatography (eluant: 20% ether–
hexane) furnished the title product 8, R1 = 4-CH(OCH2)2, as a
yellow crystalline solid (0.149 g, 0.48 mmol, 37%), mp 56–
58 ЊC. (Found: C, 53.87; H, 3.76. C14H10CrO5 requires: C, 53.85;
H, 3.87%). νmax (KBr)/cmϪ1 3083w, 2890w, 1962s, 1890s, 1880s,
1350w, 1227w, 1080w, 985w, 664m, 625m, 531w. δH (270 MHz)
16 V. V. Litvak, P. P. Kun and V. D. Shteingarts, Zh. Org. Khim., 1984,
20, 753.
17 W. Shen, Tetrahedron Lett., 1997, 38, 5575.
18 F. E. Goodson, T. I. Wallow and B. M. Novak, J. Am. Chem. Soc.,
1997, 119, 12441.
19 M. Sakamoto, I. Shimizu and A. Yamamoto, Chem. Lett., 1995,
1101.
6.28 (1 H, dd, J 10.6, 17.6 Hz, ᎐CH), 5.66 (1 H, d, J 17.6 Hz,
᎐
trans ᎐CHH), 5.60 (2 H, d, J 6.7 Hz, ArC(3,5)H), 5.55 (1 H, s,
᎐
20 H. Yang, H. Gao and R. J. Angelici, Organometallics, 1999, 18,
CH), 5.38 (2 H, d, J 6.7 Hz, ArC(2,6)H), 5.34 (1 H, d, J 10.9
2285.
Hz, cis ᎐CHH), 4.12–3.97 (4 H, s, OCH CH O); δ (68 MHz)
21 M. F. Semmelhack, G. R. Clark, J. L. Garcia, J. J. Harrison,
Y. Thebtaranonth, W. Wulff and A. Yamashita, Tetrahedron, 1981,
37, 3957.
22 C. A. L. Mahaffy, J. Organomet. Chem., 1984, 262, 33.
23 T. N. Mitchell, in Metal catalysed cross coupling reactions, ed.
F. Diederich and P. J. Stang, Weinheim, 1998.
᎐
2
2
C
232.3 (CO), 133.4 (CH), 116.9 (CH2), 105.9 (ArC(4)-CH),
101.4 (CH), 100.6 (ArC(1)-C), 91.2 (ArC(3,5)H), 88.9
(ArC(2,6)H), 65.9 (OCH2CH2O). m/z (EI) 312 (Mϩ, 36%), 256
(Mϩ Ϫ 2 × CO, 15), 228 (Mϩ Ϫ 3 × CO, 84), 200 (62), 184 (36),
52 (100). Found: Mϩ 312.0064. C14H12CrO5 requires: 312.0090.
24 X. K. Jiang, Y. H. Zhang and W. F. X. Ding, J. Chem. Soc., Perkin
Trans. 2, 1996, 1391.
ꢀ6-(Phenylbenzene)tricarbonylchromium(0) 3, R1 ؍ H, via the
Stille reaction. η6-(Fluorobenzene)tricarbonylchromium(0) 1,
R1 = H (0.300 g, 1.29 mmol) and trimethylstannylbenzene25
(0.62 g, 2.58 mmol) were treated as described above for the
vinylstannane series. FCC (eluant: 5% ether–hexane) furnished
the title product 3, R1 = H as a yellow crystalline solid (0.030 g,
0.10 mmol, 13%) with spectral data identical to those of the
Suzuki reaction product.
25 C. Eaborn and J. A. Waters, J. Chem. Soc., 1962, 1131.
26 J. W. Labadie and J. K. Stille, J. Am. Chem. Soc., 1983, 105, 6129.
27 D. F. Shriver and M. A. Drezdzon, The Manipulation of
Air-Sensitive Compounds; John Wiley & Sons, 1986.
28 C. A. L. Mahaffy and P. L. Pauson, Inorg. Synth., 1990, 28, 136.
29 I. K. Sebhat, PhD Thesis, Enantioselective deprotonation of
arenetricarbonyl chromium complexes, London, 1996.
30 W. C. Still, M. Kahn and A. Mitra, J. Org. Chem., 1978, 43, 2923.
31 A. D. Hunter, V. Mozol and S. D. Tsai, Organometallics, 1992, 11,
2251.
32 F. Rose-Munch, K. Anisos, E. Rose and J. Vaisserman, J.
Organomet. Chem., 1991, 415, 223.
ꢀ6-[4-Methoxy(phenyl)benzene]tricarbonylchromium(0)
3,
R1 ؍ MeO, via the Stille reaction. η6-(4-Methoxyfluoro-
benzene)tricarbonylchromium(0) 1, R1 = MeO (0.338 g, 1.29
mmol) and trimethylstannylbenzene25 (0.62 g, 2.58 mmol) were
treated as described above for the vinylstannane series. FCC
(eluant: 15% ether–hexane) furnished the title product 3,
33 T. E. Bitterwolf, Polyhedron, 1983, 2, 675.
34 J. L. Rosenberg and A. R. Pinder, J. Chem. Soc., Perkin Trans. 1,
1987, 747.
35 T. E. Bitterwolf and X. Dai, J. Organomet. Chem., 1992, 440, 103.
36 M. Uemura, H. Nishimura and T. Hayashi, J. Organomet. Chem.,
1994, 473, 129.
J. Chem. Soc., Perkin Trans. 1, 2000, 3808–3813
3813

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