Selective synthesis of (E)-triethyl(2-arylethenyl)silane derivatives by reaction of aryl bromides with triethyl vinylsilane catalysed by a palladium-tetraphosphine complex

Article abstract of DOI:10.1016/j.jorganchem.2005.05.014

Cis, cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane / 0.5 [PdCl(C₃H₅)]₂ system catalyses the Heck reaction of vinylsilane derivatives with a range of aryl bromides with high ratio substrate/catalyst in good yields. The formation of mixtures of styrene, (E)-triethyl(2-arylethenyl)silane and triethyl(1-arylethenyl)silane derivatives was observed in some cases. Very high selectivities (up to 100%) in favour of the formation of (E)-triethyl(2-arylethenyl)silane derivatives were obtained in the presence of sodium acetate as base. With other bases such as potassium carbonate, the formation of large amounts of styrene derivatives was observed. The reaction tolerates several functions such as fluoro, trifluoromethyl, methoxy, dimethylamino, acetyl, formyl, benzoyl, carboxylate, nitro or nitrile. Moreover, turnover numbers up to 10,000 can be obtained for this reaction.

Full text of DOI:10.1016/j.jorganchem.2005.05.014

Journal of Organometallic Chemistry 690 (2005) 3790–3802
www.elsevier.com/locate/jorganchem
Selective synthesis of (E)-triethyl(2-arylethenyl)silane derivatives
by reaction of aryl bromides with triethyl vinylsilane catalysed
by a palladium–tetraphosphine complex
b
a
b,
,b
*
Ahmed Battace , Touriya Zair , Henri Doucet *, Maurice Santelli
a
´
´
´
Laboratoire de Chimie Organique Appliquee, Faculte des Sciences, Universite Moulay Ismail, BP 4010, Beni MÕmhammed, 50000 Meknes, Morocco
b
`
´
Laboratoire de Synthese Organique, UMR 6180 CNRS and Universite dÕAix-Marseille III: ‘‘Chirotechnologies: Catalyse et Biocatalyse’’,
´ ´ ˆ
Faculte des Sciences de Saint-Jerome, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France
Received 14 March 2005; received in revised form 4 May 2005; accepted 10 May 2005
Available online 20 June 2005
Abstract
Cis, cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane / 0.5 [PdCl(C3H5)]2 system catalyses the Heck reaction of
vinylsilane derivatives with a range of aryl bromides with high ratio substrate/catalyst in good yields. The formation of mixtures
of styrene, (E)-triethyl(2-arylethenyl)silane and triethyl(1-arylethenyl)silane derivatives was observed in some cases. Very high selec-
tivities (up to 100%) in favour of the formation of (E)-triethyl(2-arylethenyl)silane derivatives were obtained in the presence of
sodium acetate as base. With other bases such as potassium carbonate, the formation of large amounts of styrene derivatives
was observed. The reaction tolerates several functions such as fluoro, trifluoromethyl, methoxy, dimethylamino, acetyl, formyl,
benzoyl, carboxylate, nitro or nitrile. Moreover, turnover numbers up to 10,000 can be obtained for this reaction.
Ó 2005 Elsevier B.V. All rights reserved.
Keywords: Tetraphosphine; Palladium; Heck-vinylation; Vinyl silanes; Aryl bromides
1. Introduction
reaction in the presence of these alkenes. The most pop-
ular one is triphenylphosphine but the palladium com-
plexes formed with this ligand are generally not very
efficient in terms of substrate/catalyst ratio, moreover,
this catalyst was used in most cases with very reactive
but expensive aryl iodides [3–9]. Tri-2-furylphosphine li-
gand in the presence of 2.5–5% Pd2(dba)3 also catalyses
the reaction of aryl iodides with 2-pyridyldim-
ethyl(vinyl)silane [10,11]. The reaction of aryl iodides
and vinylsilanes also proceeds with Pd(OAc)2 without
added ligand in the presence of tetraalkylammonium ha-
lide salts [12–14]. If monophosphine ligands have been
successfully used for the Heck reaction of vinylsilanes,
to the best of our knowledge, the efficiency of tetraphos-
phine ligands has not been demonstrated. Moreover, the
reactivity of aryl bromides with vinylsilanes has at-
tracted much less attention than the reactivity of aryl
The palladium-catalysed Heck vinylation reaction is
one of the most powerful methods for the formation
of C–C bonds [1]. For a few years, some very efficient
catalysts such as palladacycles have been described for
Heck reaction [2]. The efficiency of these catalysts for
the reaction of aryl halides with acrylates or styrenes
has been studied in detail. On the other hand, the reac-
tion in the presence of vinylsilane derivatives using these
stable palladium catalysts has attracted less attention.
Few ligands have been successfully employed for the
*
Corresponding author. Tel.: +33 4 91 28 84 16; fax: +33 4 91 98 38
65.
E-mail addresses: henri.doucet@univ.u-3mrs.fr (H. Doucet),
m.santelli@univ.u-3mrs.fr (M. Santelli).
0022-328X/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.05.014

A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
3791
2.3. Catalytic procedure for Heck reactions
Ph2P
Ph2P
PPh2
PPh2
As a typical experiment, the reaction of aryl halide
(1 mmol), alkene (2 mmol, see tables) and base (2 mmol,
see tables) at 130 °C during 20 h in a solvent (2 mL, see
tables) in the presence of cis,cis,cis-1,2,3,4-tetrakis-
(diphenylphosphinomethyl)cyclopentane/1/2 [PdCl(C3-
H5)]2 complex under argon affords the corresponding
products after addition of water, extraction with ether
or dichloromethane, separation, drying (MgSO4), evap-
oration and chromatography on silica gel.
Tedicyp
Fig. 1. Tedicyp.
iodides. Thus, an effective and selective method using
high substrate/catalyst ratios for the reaction of vinylsil-
anes with aryl bromides are still subject to significant
improvement.
In order to find more stable and more efficient palla-
dium catalysts, we have prepared the new tetrapodal
phosphine ligand, cis,cis,cis-1,2,3,4-tetrakis(diphenyl-
phosphinomethyl) cyclopentane or Tedicyp (Fig. 1)
[15] in which the four diphenylphosphinoalkyl groups
are stereospecifically bound to the same face of the
cyclopentane ring.
We have already reported that the complex formed
by association of Tedicyp with [PdCl(C3H5)]2 is an ex-
tremely efficient catalyst for allylic substitution [15],
Sonogashira reaction [16] Suzuki cross-coupling [17]
and for Heck vinylation [18]. Now, we wish to report
on the Heck vinylation of several aryl and heteroaryl
bromides with vinylsilane derivatives using Tedicyp as
ligand.
2.4. Vinylation products (Tables 1–4)
2.4.1. 4-(2-Triethylsilanyl-vinyl)acetophenone (1a)
(Table 2, entry 3) 4-Bromoacetophenone (0.199 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
(1 lmol) gave 1a in 84% (0.219 g) isolated yield. 1H
NMR (300 MHz, CDCl3): d = 7.87 (d, J = 8.3 Hz, 2H),
7.45 (d, J = 8.3 Hz, 2H), 6.88 (d, J = 19.3 Hz, 1H),
6.54 (d, J = 19.3 Hz, 1H), 2.55 (s, 3H), 0.92 (t,
J = 8.0 Hz, 9H), 0.63 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 197.6, 143.6, 142.8, 136.2,
130.2, 128.7, 126.3, 26.6, 7.3, 3.3. Anal. Calc. for
C16H24OSi: C, 73.79; H, 9.29. Found: C, 74.00; H,
9.27%. Before purification 1b was also observed: 1H
NMR (300 MHz, CDCl3): d = 5.89 (d, J = 2.8 Hz, 1H),
5.64 (d, J = 2.8 Hz, 1H). 1c was also observed: 1H
NMR (300 MHz, CDCl3): d = 6.75 (dd, J = 10.8 and
17.6 Hz, 1H), 5.86 (d, J = 17.6 Hz, 1H), 5.37 (d,
J = 10.8 Hz, 1H).
2. Experimental
2.1. General
All reactions were run under argon using vacuum
lines in Schlenk tubes in oven-dried glassware. The sol-
vents were not distilled before use. Commercial vinylsi-
lane derivatives and aryl halides were used without
purification. The reactions were followed by GC and
NMR for high boiling point substrates and by GC for
low boiling point substrates. 1H (300 MHz) and 13C
(75 MHz) spectra were recorded in CDCl3 solutions.
Chemical shift (d) are reported in ppm relative to
CDCl3. Flash chromatographies were performed on sil-
ica gel (230–400 mesh) eluting with ether/pentane
mixtures.
2.4.2. 4-(2-Triethylsilanyl-vinyl)benzaldehyde (2a)
(Table 2, entry 8) 4-Bromobenzaldehyde (0.185 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
(0.1 lmol) gave 2a in 87% (0.214 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 9.98 (s, 1H), 7.83 (d,
J = 8.1 Hz, 2H), 7.56 (d, J = 8.1 Hz, 2H), 6.93 (d,
J = 19.2 Hz, 1H), 6.63 (d, J = 19.2 Hz, 1H), 0.95 (t,
J = 8.0 Hz, 9H), 0.68 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 191.8, 144.1, 143.5, 135.6,
131.3, 130.1, 126.8, 7.3, 3.4. Anal. Calc. for C15H22OSi:
C, 73.11; H, 9.00. Found: C, 73.28; H, 9.17%. Before
purification 2b was also observed: 1H NMR
(300 MHz, CDCl3): d = 5.90 (d, J = 2.8 Hz, 1H),
5.66 (d, J = 2.8 Hz, 1H). 2c was also observed: 1H
NMR (300 MHz, CDCl3): d = 6.77 (dd, J = 10.8 and
17.6 Hz, 1H), 5.92 (d, J = 17.6 Hz, 1H), 5.43 (d,
J = 10.8 Hz, 1H).
2.2. Preparation of the Pd-tedicyp catalyst [15]
An over-dried 40-mL Schlenk tube equipped with a
magnetic stirring bar, under argon atmosphere, was
charged with [Pd(g3-C3H5)Cl]2 (4.2 mg, 11.6 lmol) and
Tedicyp (20 mg, 23.2 lmol). About 2.5 mL of anhy-
drous DMF were added, then the solution was stirred
at room temperature for 10 min. The appropriate
amount of catalyst (see tables) was transferred to the
mixture of aryl halide, alkene and base in DMF (see Sec-
tion 2.3).
2.4.3. 4-(2-Triethylsilanyl-vinyl)toluene (3a)
(Table 2, entry 22) 4-Bromotoluene (0.171 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex

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A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
Table 1
Influence of the solvent, base and vinylsilane derivative on the selectivity of the reaction (Scheme 1)
Entry Aryl bromide
Ratio substrate/ Solvent
catalyst
Base
Vinylsilane
Product Ratio a/b/ca Yield (%)
1
2
4-Bromoacetophenone 1000
DMF
K2CO3
K2CO3
K2CO3
K2CO3
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
1a–c
1a–c
1a–c
1a–c
–
27/5/68
58/4/38
69/3/28
31/3/66
–
88
50
4-Bromoacetophenone
4-Bromoacetophenone
4-Bromoacetophenone
4-Bromoacetophenone
4-Bromobenzaldehyde
4-Bromotoluene
250
250
Xylene
NMP
DMAC
3
87
4
250
250
100
0
5
Ethylene glycol K2CO3
6
1000
250
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
Na2CO3
2a–c
3a–c
4a–c
5a–c
6a–c
6a–c
6a–c
6a–c
6a–c
6a–c
6a–c
6a–c
6a–c
66/4/30
75/6/19
42/9/49
65/1/34
46/8/46
49/7/44
49/8/43
72/4/24
61/11/28
91/6/3
89/7/4
93/6/1
93/5/2
93/7/0
86/12/2
85/13/2
94/6/0
–
100
100
97
7
8
4-Bromoanisole
1-Bromonaphthalene
1000
250
9
100
95
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
4-tButylbromobenzene 1000
4-tButylbromobenzene
4-tButylbromobenzene
4-tButylbromobenzene
4-tButylbromobenzene
250
250
250
250
100
100
100
100
100
100b
84b
NaHCO3 Vinyltriethylsilane
Cs2CO3
KF
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
Vinyltriethylsilane
4-tButylbromobenzene 1000
4-tButylbromobenzene 250
4-tButylbromobenzene 1000
4-tButylbromobenzene 250
AcONa
AcONa
AcONa
AcONa
AcONa
AcONa
AcONa
AcONa
AcONa
AcONa
80c
4-tButylbromobenzene 1000
4-Bromoacetophenone 1000
4-Bromobenzophenone 1000
Dimethylphenylvinylsilane 7a,b
Dimethylphenylvinylsilane 8a–c
Dimethylphenylvinylsilane 9a–c
Dimethylphenylvinylsilane 10a,b
75 (67)
100 (83)
100 (81)
98 (80)
0
1-Bromonaphthalene
4-Bromoacetophenone
250
250
Vinyltriphenylsilane
Vinyltriphenylsilane
–
–
4-tButylbromobenzene 1000
–
0
Conditions: catalyst [Pd(C3H5)Cl]2/Tedicyp 1/2, aryl bromide (1 eq.), vinylsilane derivative (2 eq.), base (2 eq.), 130 °C, 20 h, GC and NMR yields,
yields in parenthesis are isolated yields of product a.
a
See Scheme 1.
Reaction temperature 100 °C.
Reaction temperature 80 °C.
b
c
(1 lmol) gave 3a in 90% (0.209 g) isolated yield. 1H
NMR (300 MHz, CDCl3): d = 7.33 (d, J = 8.1 Hz, 2H),
7.12 (d, J = 8.1 Hz, 2H), 6.85 (d, J = 19.2 Hz, 1H),
6.35 (d, J = 19.2 Hz, 1H), 2.33 (s, 3H), 0.96 (t,
J = 8.0 Hz, 9H), 0.66 (q, J = 8.0 Hz, 6H). Before purifi-
cation 3b was also observed: 1H NMR (300 MHz,
CDCl3): d = 5.86 (d, J = 2.8 Hz, 1H), 5.66 (d,
J = 2.8 Hz, 1H). 3c was also observed: 1H NMR
(300 MHz, CDCl3): d = 5.73 (d, J = 17.6 Hz, 1H), 5.20
(d, J = 10.8 Hz, 1H).
J = 10.8 and 17.6 Hz, 1H), 5.60 (d, J = 17.6 Hz, 1H),
5.12 (d, J = 10.8 Hz, 1H).
2.4.5. Triethyl-[2-(naphthalen-1-yl)-vinyl]silane (5a)
(Table 3, entry 15) 1-Bromonaphthalene (0.207 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
(1 lmol) gave 5a in 88% (0.236 g) isolated yield. 1H
NMR (300 MHz, CDCl3): d = 8.14 (d, J = 8.2 Hz, 1H),
7.83 (d, J = 8.2 Hz, 1H), 7.77 (d, J = 8.0 Hz, 1H),
7.73–7.62 (m, 2H), 7.55–7.41 (m, 3H), 6.48 (d,
J = 19.2 Hz, 1H), 1.01 (t, J = 8.0 Hz, 9H), 0.73 (q,
J = 8.0 Hz, 6H). Before purification 5b was also ob-
served: 1H NMR (300 MHz, CDCl3): d = 5.92 (d,
J = 2.8 Hz, 1H), 5.84 (d, J = 2.8 Hz, 1H). 5c was also
observed: 1H NMR (300 MHz, CDCl3): d = 5.78 (d,
J = 17.6 Hz, 1H), 5.47 (d, J = 10.8 Hz, 1H).
2.4.4. 4-(2-Triethylsilanyl-vinyl)anisole (4a)
(Table 2, entry 26) 4-Bromoanisole (0.187 g, 1 mmol),
vinyltriethylsilane (0.284 g, 2 mmol), sodium acetate
(0.164 g, 2 mmol), DMF (2 mL) and Pd complex
(1 lmol) gave 4a in 86% (0.214 g) isolated yield. 1H
NMR (300 MHz, CDCl3): d = 7.39 (d, J = 8.4 Hz, 2H),
6.86 (d, J = 8.4 Hz, 2H), 6.83 (d, J = 19.2 Hz, 1H),
6.24 (d, J = 19.2 Hz, 1H), 3.81 (s, 3H), 0.98 (t,
J = 8.0 Hz, 9H), 0.66 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 159.5, 144.2, 131.6, 127.5,
123.0, 113.9, 55.3, 7.4, 3.6. Before purification 4b was
2.4.6. 4-(2-Triethylsilanyl-vinyl)-tert-butylphenyl (6a)
(Table 2, entry 24) 4-t Butylbromobenzene (0.213 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
(1 lmol) gave 6a in 86% (0.236 g) isolated yield. 1H
NMR (300 MHz, CDCl3): d = 7.38 (m, 4H), 6.89 (d,
J = 19.2 Hz, 1H), 6.38 (d, J = 19.2 Hz, 1H), 1.32 (s,
1
also observed: H NMR (300 MHz, CDCl3): d = 5.85
(d, J = 2.8 Hz, 1H), 5.51 (d, J = 2.8 Hz, 1H). 4c was also
1
observed: H NMR (300 MHz, CDCl3): d = 6.67 (dd,

A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
3793
Table 2
Palladium catalysed Heck reactions with vinyltriethylsilane and para-substituted aryl bromides (Scheme 1)
Entry
Aryl bromide
Ratio substrate/catalyst
Product
Ratio a/b/ca
Yield (%)
1
2
Iodobenzene
Iodobenzene
1000
10000
1000
11a,b
11a,b
1a–c
92/8/0
91/9/0
88/6/6
90/4/6
90/8/2
90/6/4
95/3/2
94/4/2
96/4/0
92/6/2
95/5/0
95/5/0
91/5/4
94/6/0
92/8/0
90/2/8
98/2/0
98/2/0
95/5/0
96/4/0
96/4/0
96/3/1
94/6/0
91/6/3
90/6/4
92/4/4
83/5/12
87/7/6
96/4/0
84/5/11
100 (87)
95
3
4-Bromoacetophenone
4-Bromoacetophenone
4-Bromobenzophenone
4-Bromobenzophenone
4-Bromobenzaldehyde
4-Bromobenzaldehyde
Methyl 4-bromobenzoate
Methyl 4-bromobenzoate
4-Trifluoromethylbromobenzene
4-Trifluoromethylbromobenzene
4-Bromobenzonitrile
100 (84)
92
100
4
10,000
1000
1a–c
5
12a–c
12a–c
2a–c
6
10,000
1000
100 (83)
100
7
8
10,000
1000
2a–c
100 (87)
100 (90)
91
9
13a,b
13a–c
14a,b
14a,b
15a–c
15a,b
16a,b
16a–c
17a,b
17a,b
18a,b
18a,b
11a,b
3a–c
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
10,000
1000
100
100 (89)
100
10,000
1000
4-Bromobenzonitrile
10,000
250
1000
100 (89)
100
4-Bromonitrobenzene
4-Bromonitrobenzene
3,5-bis (Trifluoromethyl)bromobenzene
3,5-bis (Trifluoromethyl)bromobenzene
4-Fluorobromobenzene
4-Fluorobromobenzene
Bromobenzene
100 (81)
100
1000
10,000
1000
100 (91)
100 (86)
75
10,000
1000
1000
100
99 (90)
83
4-Bromotoluene
4-Bromotoluene
10,000
1000
3a,b
6a–c
4-tButylbromobenzene
4-tButylbromobenzene
4-Bromoanisole
100 (86)
56
10,000
1000
6a–c
4a–c
100 (86)
74
4-Bromoanisole
10,000
1000
4a–c
2-Bromo-6-methoxynaphthalene
2-Bromo-6-methoxynaphthalene
4-Dimethylaminobromobenzene
19a–c
19a–c
20a–c
100 (81)
78
100 (76)
10,000
1000
Conditions: catalyst [Pd(C3H5)Cl]2/Tedicyp 1/2, aryl halide (1 eq.), vinyltriethylsilane (2 eq.), AcONa (2 eq.), DMF, 130 °C, 20 h, GC and NMR
yields, yields in parenthesis are isolated yields of product a.
a
See Scheme 1.
9H), 0.99 (t, J = 8.0 Hz, 9H), 0.66 (q, J = 8.0 Hz, 6H).
13C NMR (75 MHz, CDCl3): d = 151.0, 144.6, 135.8,
126.0, 125.4, 124.8, 34.6, 31.3, 7.4, 3.5. Anal. Calc. for
C18H30Si: C, 78.75; H, 11.02. Found: C, 78.60; H,
2.4.8. [2-(4-Acetylphenyl)vinyl]dimethylphenylsilane
(8a)
(Table 1, entry 20) 4-Bromoacetophenone (0.199 g,
1 mmol), dimethylphenylvinylsilane (0.324 g, 2 mmol),
sodium acetate (0.164 g, 2 mmol), DMF (2 mL) and
Pd complex (1 lmol) gave 8a in 83% (0.233 g) isolated
yield. 1H NMR (300 MHz, CDCl3): d = 7.92 (d,
J = 8.4 Hz, 2H), 7.58 (m, 2H), 7.51 (d, J = 8.4 Hz,
2H), 7.39 (m, 3H), 6.97 (d, J = 19.2 Hz, 1H), 6.75 (d,
J = 19.2 Hz, 1H), 2.59 (s, 3H), 0.46 (s, 6H). Before puri-
fication 8b was also observed: 1H NMR (300 MHz,
CDCl3): d = 6.02 (d, J = 2.8 Hz, 1H), 5.76 (d,
J = 2.8 Hz, 1H). 8c was also observed: 1H NMR
(300 MHz, CDCl3): d = 5.88 (d, J = 17.6 Hz, 1H), 5.40
(d, J = 10.8 Hz, 1H).
1
11.21%. Before purification 6b was also observed: H
NMR (300 MHz, CDCl3): d = 5.90 (d, J = 2.8 Hz, 1H),
5.55 (d, J = 2.8 Hz, 1H). 6c was also observed: 1H
NMR (300 MHz, CDCl3): d = 5.71 (d, J = 17.6 Hz,
1H), 5.19 (d, J = 10.8 Hz, 1H).
2.4.7. [2-(4-tert-Butyl-phenyl)-vinyl]-dimethylphenyl-
silane (7a)
(Table 1, entry 19) 4-tButylbromobenzene (0.213 g,
1 mmol), dimethylphenylvinylsilane (0.324 g, 2 mmol),
sodium acetate (0.164 g, 2 mmol), DMF (2 mL) and
Pd complex (1 lmol) gave 7a in 67% (0.197 g) isolated
2.4.9. [2-(4-Benzoylphenyl)vinyl]dimethylphenylsilane
(9a)
1
yield. H NMR (300 MHz, CDCl3): d = 7.56 (m, 3H),
(Table 1, entry 21) 4-Bromobenzophenone (0.261 g,
1 mmol), dimethylphenylvinylsilane (0.324 g, 2 mmol),
sodium acetate (0.164 g, 2 mmol), DMF (2 mL) and
Pd complex (1 lmol) gave 9a in 81% (0.277 g) isolated
7.45–7.32 (m, 6H), 6.95 (d, J = 19.2 Hz, 1H), 6.56 (d,
J = 19.2 Hz, 1H), 1.33 (s, 9H), 0.44 (s, 6H). Before puri-
fication 7b was also observed: 1H NMR (300 MHz,
CDCl3): d = 6.04 (d, J = 2.8 Hz, 1H), 5.66 (d,
J = 2.8 Hz, 1H).
1
yield. H NMR (300 MHz, CDCl3): d = 7.80 (m, 4H),

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A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
Table 3
Palladium catalysed Heck reactions with vinyltriethylsilane and meta- or ortho-substituted aryl bromides (Scheme 1)
Entry
Aryl bromide
Ratio substrate/catalyst
Product
Ratio a/b/ca
Yield (%)
1
2
3-Trifluoromethylbromobenzene
3-Trifluoromethylbromobenzene
3-Bromobenzaldehyde
3-Bromobenzaldehyde
2-Bromoacetophenone
Methyl 2-bromobenzoate
Methyl 2-bromobenzoate
2-Trifluoromethylbromobenzene
2-Bromobenzonitrile
1000
10,000
1000
10,000
100
21a,b
21a,b
22a,b
22a,b
23a,b
24a–c
24a,c
25a
94/6/0
95/5/0
98/2/0
94/6/0
86/14/0
94/2/4
97/0/3
100/0/0
98/2/0
98/2/0
95/5/0
97/3/0
97/3/0
98/2/0
95/2/3
96/4/0
100/0/0
100/0/0
90/6/4
93/2/5
59/0/41
95/0/5
98/0/2
100
100 (92)
100 (91)
100
3
4
5
66 (52)
94
6
250
7
1000
1000
100
90 (84)
100 (92)
80 (72)
49
8
9
26a,b
26a,b
27a,b
27a,b
28a,b
28a,b
5a–c
10
11
12
13
14
15
16
17
18
19
20
21
22
23
2-Bromobenzonitrile
250
100
2-Bromonitrobenzene
2-Bromonitrobenzene
2-Fluorobromobenzene
2-Fluorobromobenzene
1-Bromonaphthalene
1-Bromonaphthalene
2-Bromotoluene
85 (79)
23
250
1000
10,000
1000
10,000
250
100 (91)
67
100 (88)
50
5a,b
29a
100 (93)
74
2-Bromotoluene
2-Bromoanisole
1000
100
29a
30a–c
30a–c
31a,c
32a,c
32a,c
64 (54)
31
2-Bromoanisole
9-Bromoanthracene
250
100
63 (37)
65 (57)
41
2,4,6-Trimethylbromobenzene
2,4,6-Trimethylbromobenzene
250
1000
Conditions: catalyst [Pd(C3H5)Cl]2/Tedicyp 1/2, aryl bromide (1 eq.), vinyltriethylsilane (2 eq.), AcONa (2 eq.), DMF, 130 °C, 20 h, GC and NMR
yields, yields in parenthesis are isolated yields of product a.
a
See Scheme 1.
Table 4
Palladium catalysed Heck reactions with vinyltriethylsilane and heteroaryl bromides (Scheme 1)
Entry
Aryl bromide
Ratio substrate/catalyst
Product
Ratio a/b/ca
Yield (%)
1
2
3-Bromopyridine
3-Bromopyridine
1000
10,000
250
33a–c
33a,b
34a–c
34a,b
35a,b
35a–c
36a–c
36a–c
37a,b
37a,b
38a–c
38a,b
94/4/2
95/5/0
96/3/1
97/3/0
91/9/0
87/7/6
93/2/5
93/2/5
94/6/0
94/6/0
92/7/1
95/5/0
100 (86)
100
3
4-Bromopyridine hydrochloride
4-Bromopyridine hydrochloride
3-Bromoquinoline
100 (92)b
100b
4
1000
1000
10,000
250
5
100 (85)
56
6
3-Bromoquinoline
7
4-Bromoisoquinoline
4-Bromoisoquinoline
2-Bromothiophene
100 (84)
100
8
1000
100
9
100 (85)
10
10
11
12
2-Bromothiophene
3-Bromothiophene
3-Bromothiophene
250
100
100 (87)
56
250
Conditions: catalyst [Pd(C3H5)Cl]2/Tedicyp 1/2, aryl bromide (1 eq.), vinyltriethylsilane (2 eq.), AcONa (2 eq.), DMF, 130 °C, 20 h, GC and NMR
yields, yields in parenthesis are isolated yields of product a.
a
See Scheme 1.
b
AcONa 3 eq.
7.64–7.35 (m, 10H), 7.02 (d, J = 19.2 Hz, 1H), 6.78 (d,
J = 19.2 Hz, 1H), 0.50 (s, 6H). Before purification 9b
was also observed: 1H NMR (300 MHz, CDCl3):
d = 6.07 (d, J = 2.8 Hz, 1H), 5.79 (d, J = 2.8 Hz, 1H).
9c was also observed: 1H NMR (300 MHz, CDCl3):
d = 5.90 (d, J = 17.6 Hz, 1H), 5.42 (d, J = 10.8 Hz, 1H).
Pd complex (4 lmol) gave 10a in 80% (0.231 g) isolated
yield. 1H NMR (300 MHz, CDCl3): d = 8.10 (d,
J = 8.5 Hz, 1H), 7.90–7.35 (m, 12H), 6.67 (d,
J = 19.2 Hz, 1H), 0.51 (s, 6H). Before purification 10c
was also observed: 1H NMR (300 MHz, CDCl3):
d = 5.93 (d, J = 17.6 Hz, 1H), 5.87 (d, J = 10.8 Hz, 1H).
2.4.10. Dimethyl-[(2-naphthalen-1-yl)-vinyl]-phenyl-
silane (10a)
(Table 1, entry 22) 1-Bromonaphthalene (0.207 g,
1 mmol), dimethylphenylvinylsilane (0.324 g, 2 mmol),
sodium acetate (0.164 g, 2 mmol), DMF (2 mL) and
2.4.11. Triethylstyrylsilane (11a)
(Table 2, entry 1) Iodobenzene (0.204 g, 1 mmol),
vinyltriethylsilane (0.284 g, 2 mmol), sodium acetate
(0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
(1 lmol) gave 11a in 87% (0.190 g) isolated yield. H

A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
3795
NMR (300 MHz, CDCl3): d = 7.44 (d, J = 8.3 Hz, 2H),
7.34 (t, J = 7.7 Hz, 2H), 7.25 (m, 1H), 6.90 (d,
J = 19.3 Hz, 1H), 6.42 (d, J = 19.3 Hz, 1H), 0.99 (t,
J = 8.0 Hz, 9H), 0.65 (q, J = 8.0 Hz, 6H). Before purifi-
cation 11b was also observed: 1H NMR (300 MHz,
cation 14b was also observed: 1H NMR (300 MHz,
CDCl3): d = 5.88 (d, J = 2.8 Hz, 1H), 5.65 (d,
J = 2.8 Hz, 1H).
2.4.15. 4-(2-Triethylsilanyl-vinyl)-benzonitrile (15a)
(Table 2, entry 14) 4-Bromobenzonitrile (0.182 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd com-
plex (0.1 lmol) gave 15a in 89% (0.217 g) isolated
yield. 1H NMR (300 MHz, CDCl3): d = 7.59 (d,
J = 8.4 Hz, 2H), 7.49 (d, J = 8.4 Hz, 2H), 6.88 (d,
J = 19.0 Hz, 1H), 6.59 (d, J = 19.0 Hz, 1H), 0.98 (t,
J = 8.0 Hz, 9H), 0.67 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 142.8, 142.5, 132.3, 131.5,
126.7, 118.9, 110.9, 7.3, 3.3. Anal. Calc. for
C15H21NSi: C, 74.01; H, 8.70. Found: C, 74.12; H,
CDCl3): d = 5.86 (d, J = 2.8 Hz,
J = 2.8 Hz, 1H).
1 H), 5.57 (d,
2.4.12. 4-(2-Triethylsilanyl-vinyl)-benzophenone (12a)
(Table 2, entry 6) 4-Bromobenzophenone (0.261 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
(0.1 lmol) gave 12a in 83% (0.267 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.78 (m, 4H), 7.62–7.40
(m, 5H), 6.95 (d, J = 19.2 Hz, 1H), 6.60 (d,
J = 19.2 Hz, 1H), 0.97 (t, J = 8.0 Hz, 9H), 0.70 (q,
J = 8.0 Hz, 6H). 13C NMR (75 MHz, CDCl3):
d = 196.3, 143.8, 142.4, 138.0, 136.8, 132.4, 130.7,
130.1, 130.0, 128.4, 126.2, 7.5, 3.5. Anal. Calc. for
C21H26OSi: C, 78.21; H, 8.13. Found: C, 78.02; H,
1
8.49%. Before purification 15b was also observed: H
NMR (300 MHz, CDCl3): d = 5.87 (d, J = 2.8 Hz,
1H), 5.65 (d, J = 2.8 Hz, 1H). 15c was also observed:
1H NMR (300 MHz, CDCl3): d = 5.90 (d, J =
17.6 Hz, 1H), 5.46 (d, J = 10.8 Hz, 1H).
1
8.28%. Before purification 12b was also observed: H
NMR (300 MHz, CDCl3): d = 5.93 (d, J = 2.8 Hz, 1H),
5.66 (d, J = 2.8 Hz, 1H). 12c was also observed: 1H
NMR (300 MHz, CDCl3): d = 5.94 (d, J = 17.6 Hz,
1H), 5.40 (d, J = 10.8 Hz, 1H).
2.4.16. 4-(2-Triethylsilanyl-vinyl)-nitrobenzene (16a)
(Table 2, entry 16) 4-Bromonitrobenzene (0.202 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
2.4.13. 4-(2-Triethylsilanyl-vinyl)-benzoic acid methyl
ester (13a)
(1 lmol) gave 16a in 81% (0.213 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 8.18 (d, J = 8.8 Hz, 2H),
7.54 (d, J = 8.8 Hz, 2H), 6.93 (d, J = 19.2 Hz, 1H),
6.66 (d, J = 19.2 Hz, 1H), 0.99 (t, J = 8.0 Hz, 9H), 0.68
(q, J = 8.0 Hz, 6H). 13C NMR (75 MHz, CDCl3):
d = 147.1, 144.4, 142.4, 132.9, 126.8, 123.9, 7.3, 3.3.
Anal. Calc. for C14H21NO2Si: C, 63.84; H, 8.04. Found:
C, 64.02;H, 8.31%. Before purification 16b was also ob-
served: 1H NMR (300 MHz, CDCl3): d = 5.91 (d,
J = 2.8 Hz, 1H), 5.69 (d, J = 2.8 Hz, 1H). 16c was also
observed: 1H NMR (300 MHz, CDCl3): d = 5.93 (d,
J = 17.6 Hz, 1H), 5.42 (d, J = 10.8 Hz, 1H).
(Table 2, entry 9) Methyl 4-bromobenzoate (0.215 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
(1 lmol) gave 13a in 90% (0.249 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.98 (d, J = 7.5 Hz, 2H),
7.47 (d, J = 7.5 Hz, 2H), 6.91 (d, J = 19.2 Hz, 1H),
6.56 (d, J = 19.2 Hz, 1H), 3.90 (s, 3H), 0.97 (t,
J = 8.0 Hz, 9H), 0.67 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 168.9, 143.7, 142.7, 129.9,
129.8, 129.2, 126.2, 52.0, 7.3, 3.4. Anal. Calc. for
C16H24O2Si: C, 69.51; H, 8.75. Found: C, 69.32; H,
1
8.49%. Before purification 13b was also observed: H
2.4.17. [2-(3,5-Bis-trifluoromethyl-phenyl)-vinyl]-
triethylsilane (17a)
NMR (300 MHz, CDCl3): d = 5.88 (d, J = 2.8 Hz, 1H),
5.62 (d, J = 2.8 Hz, 1H). 13c was also observed: 1H
NMR (300 MHz, CDCl3): d = 6.74 (dd, J = 10.8 and
17.6 Hz, 1H), 5.84 (d, J = 17.6 Hz, 1H), 5.36 (d,
J = 10.8 Hz, 1H).
(Table 2, entry 18) 3,5-Bis(trifluoromethyl)bromo-
benzene (0.293 g, 1 mmol), vinyltriethylsilane (0.284 g,
2 mmol), sodium acetate (0.164 g, 2 mmol), DMF
(2 mL) and Pd complex (0.1 lmol) gave 17a in 91%
1
(0.322 g) isolated yield. H NMR (300 MHz, CDCl3):
2.4.14. Triethyl-[2-(4-trifluoromethyl-phenyl)-vinyl]-
silane (14a)
d = 7.83 (s, 2H), 7.73 (s, 1H), 6.92 (d, J = 19.2 Hz,
1H), 6.61 (d, J = 19.2 Hz, 1H), 0.99 (t, J = 8.0 Hz,
9H), 0.68 (q, J = 8.0 Hz, 6H). 13C NMR (75 MHz,
CDCl3): d = 141.6, 140.2, 131.7 (q, J = 33.2 Hz),
131.6, 126.1, 123.2 (q, J = 273.0 Hz), 121.1 (q,
J = 4.0 Hz), 7.3, 3.3. Anal. Calc. for C16H20F6Si: C,
54.22; H, 5.69. Found: C, 54.21; H, 5.79%. Before
purification 17b was also observed: 1H NMR
(300 MHz, CDCl3): d = 5.93 (d, J = 2.8 Hz, 1H), 5.72
(d, J = 2.8 Hz, 1H).
(Table 2, entry 12) 4-Trifluoromethylbromobenzene
(0.225 g, 1 mmol), vinyltriethylsilane (0.284 g, 2 mmol),
sodium acetate (0.164 g, 2 mmol), DMF (2 mL) and
Pd complex (0.1 lmol) gave 14a in 89% (0.255 g) iso-
1
lated yield. H NMR (300 MHz, CDCl3): d = 7.57 (d,
J = 8.1 Hz, 2H), 7.52 (d, J = 8.1 Hz, 2H), 6.91 (d,
J = 19.2 Hz, 1H), 6.55 (d, J = 19.2 Hz, 1H), 0.99 (t,
J = 8.0 Hz, 9H), 0.68 (q, J = 8.0 Hz, 6H). Before purifi-

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A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
2.4.18. 4-(2-Triethylsilanyl-vinyl)-fluorobenzene (18a)
(Table 2, entry 19) 4-Fluorobromobenzene (0.175 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
2.4.21. Triethyl-[2-(3-trifluoromethyl-phenyl)-vinyl]-
silane (21a)
(Table 3, entry 2) 3-Trifluoromethylbromobenzene
(0.225 g, 1 mmol), vinyltriethylsilane (0.284 g, 2 mmol),
sodium acetate (0.164 g, 2 mmol), DMF (2 mL) and
Pd complex (0.1 lmol) gave 21a in 92% (0.263 g) iso-
1
(1 lmol) gave 18a in 86% (0.203 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.40 (dd, J = 5.5 and
8.7 Hz, 2H), 7.00 (t, J = 8.7 Hz, 2H), 6.84 (d,
J = 19.2 Hz, 1H), 6.32 (d, J = 19.2 Hz, 1H), 0.97 (t,
J = 8.0 Hz, 9H), 0.66 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 162.9 (d, J = 244.4 Hz), 143.9,
135.1, 128.1 (d, J = 8.2 Hz), 126.1, 115.7 (d,
J = 21.9 Hz), 7.8, 3.9. Anal. Calc. for C14H21FSi: C,
71.13; H, 8.95. Found: C, 71.29; H, 9.14%. Before puri-
fication 18b was also observed: 1H NMR (300 MHz,
CDCl3): d = 5.83 (d, J = 2.8 Hz, 1H), 5.55 (d,
J = 2.8 Hz, 1H).
1
lated yield. H NMR (300 MHz, CDCl3): d = 7.67 (s,
1H), 7.60 (d, J = 7.5 Hz, 1H), 7.52–7.35 (m, 2H), 6.90
(d, J = 19.2 Hz, 1H), 6.52 (d, J = 19.2 Hz, 1H), 0.99 (t,
J = 8.0 Hz, 9H), 0.67 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 143.2, 139.2, 130.9 (q,
J = 32.1 Hz), 129.4, 128.8, 128.7, 124.3 (q, J = 4.0 Hz),
124.1 (q, J = 272.5 Hz), 123.0 (q, J = 3.4 Hz), 7.3, 3.4.
Anal. Calc. for C15H21F3Si: C, 62.90; H, 7.39. Found:
C, 63.06; H, 7.24%. Before purification 21b was also ob-
served: 1H NMR (300 MHz, CDCl3): d = 5.89 (d,
J = 2.8 Hz, 1H), 5.64 (d, J = 2.8 Hz, 1H).
2.4.19. Triethyl-[2-(6-methoxy-naphthalen-2-yl)-
vinyl]silane (19a)
2.4.22. 3-(2-Triethylsilanyl-vinyl)benzaldehyde (22a)
(Table 3, entry 3) 3-Bromobenzaldehyde (0.185 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
(Table 2, entry 28) 2-Bromo-6-methoxynaphthalene
(0.237 g, 1 mmol), vinyltriethylsilane (0.284 g, 2 mmol),
sodium acetate (0.164 g, 2 mmol), DMF (2 mL) and
Pd complex (1 lmol) gave 19a in 81% (0.242 g) iso-
lated yield. 1H NMR (300 MHz, CDCl3): d = 7.72–
7.63 (m, 4H), 7.12 (m, 2H), 7.02 (d, J = 19.2 Hz,
1H), 6.47 (d, J = 19.2 Hz, 1H), 3.91 (s, 3H), 0.97 (t,
J = 8.0 Hz, 9H), 0.69 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 157.8, 144.9, 134.4, 134.0,
129.6, 129.0, 126.9, 126.3, 125.0, 123.9, 118.9, 105.8,
55.2, 7.4, 3.6. Anal. Calc. for C19H26OSi: C, 76.45;
H, 8.78. Found: C, 76.22; H, 8.77%. Before purifica-
tion 19b was also observed: 1H NMR (300 MHz,
CDCl3): d = 5.96 (d, J = 2.8 Hz, 1H), 5.62 (d,
J = 2.8 Hz, 1H). 19c was also observed: 1H NMR
(300 MHz, CDCl3): d = 5.81 (d, J = 17.6 Hz, 1H),
5.27 (d, J = 10.8 Hz, 1H).
1
(1 lmol) gave 22a in 91% (0.224 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 10.0 (s, 1H), 7.94 (s,
1H), 7.75 (d, J = 7.5 Hz, 1H), 7.68 (d, J = 7.5 Hz, 1H),
7.49 (t, J = 7.5 Hz, 1H), 6.94 (d, J = 19.2 Hz, 1H), 6.55
(d, J = 19.2 Hz, 1H), 0.99 (t, J = 8.0 Hz, 9H), 0.67 (q,
J = 8.0 Hz, 6H). 13C NMR (75 MHz, CDCl3):
d = 192.4, 143.2, 139.4, 136.6, 132.2, 129.2, 129.0,
128.7, 127.2, 7.3, 3.4. Anal. Calc. for C15H22OSi: C,
73.11; H, 9.00. Found: C, 73.31; H, 8.87%. Before puri-
fication 22b was also observed: 1H NMR (300 MHz,
CDCl3): d = 5.92 (d, J = 2.8 Hz, 1H), 5.66 (d,
J = 2.8 Hz, 1H).
2.4.23. 2-(2-Triethylsilanyl-vinyl)acetophenone (23a)
(Table 3, entry 5) 2-Bromoacetophenone (0.199 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
2.4.20. Dimethyl-[4-(2-triethylsilanyl-vinyl)-phenyl]-
amine (20a)
1
(10 lmol) gave 23a in 52% (0.135 g) isolated yield. H
(Table 2, entry 30) 4-Bromo-N,N-dimethylaniline
(0.200 g, 1 mmol), vinyltriethylsilane (0.284 g, 2 mmol),
sodium acetate (0.164 g, 2 mmol), DMF (2 mL) and
Pd complex (1 lmol) gave 20a in 76% (0.199 g) iso-
lated yield. 1H NMR (300 MHz, CDCl3): d = 7.33
(d, J = 8.6 Hz, 2H), 6.80 (d, J = 19.2 Hz, 1H), 6.67
(d, J = 8.6 Hz, 2H), 6.14 (d, J = 19.2 Hz, 1H), 2.96
(s, 6H), 0.97 (t, J = 8.0 Hz, 9H), 0.63 (q, J = 8.0 Hz,
6H). 13C NMR (75 MHz, CDCl3): d = 150.3, 144.7,
127.5, 127.4, 120.0, 112.3, 40.5, 7.4, 3.6. Anal. Calc.
for C16H27NSi: C, 73.49; H, 10.41. Found: C, 73.37;
H, 10.67%. Before purification 20b was also observed:
1H NMR (300 MHz, CDCl3): d = 5.85 (d, J = 2.8 Hz,
1H), 5.44 (d, J = 2.8 Hz, 1H). 20c was also observed:
1H NMR (300 MHz, CDCl3): d = 5.53 (d, J =
17.6 Hz, 1H), 5.02 (d, J = 10.8 Hz, 1 H).
NMR (300 MHz, CDCl3): d = 7.58 (m, 2H), 7.44 (t,
J = 7.5 Hz, 1H), 7.34 (d, J = 19.2 Hz, 1H), 7.31 (t,
J = 7.5 Hz, 1H), 6.31 (d, J = 19.2 Hz, 1H), 2.57 (s,
3H), 1.00 (t, J = 8.0 Hz, 9H), 0.67 (q, J = 8.0 Hz, 6H).
13C NMR (75 MHz, CDCl3): d = 202.3, 143.7, 138.9,
137.5, 131.4, 130.2, 128.4, 127.5, 127.3, 29.9, 7.3, 3.5.
Anal. Calc. for C16H24OSi: C, 73.79; H, 9.29. Found:
C, 73.50; H, 9.47%. Before purification 23b was also ob-
served: 1H NMR (300 MHz, CDCl3): d = 5.64 (d,
J = 2.8 Hz, 1H), 5.62 (d, J = 2.8 Hz, 1H).
2.4.24. 2-(2-Triethylsilanyl-vinyl)-benzoic acid methyl
ester (24a)
(Table 3, entry 7) Methyl 2-bromobenzoate (0.215 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium

A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
3797
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
7.64 (d, J = 7.8 Hz, 1H), 7.56 (t, J = 7.5 Hz, 1H), 7.37
(t, J = 7.5 Hz, 1H), 7.30 (d, J = 19.2 Hz, 1H), 6.43 (d,
J = 19.2 Hz, 1H), 0.99 (t, J = 8.0 Hz, 9H), 0.67 (q,
J = 8.0 Hz, 6H). 13C NMR (75 MHz, CDCl3):
d = 147.7, 139.8, 134.6, 133.1, 132.9, 128.5, 128.1,
124.2, 7.3, 3.3. Anal. Calc. for C14H21NO2Si: C, 63.84;
H, 8.04. Found: C, 63.59; H, 8.05%. Before purification
(1 lmol) gave 24a in 84% (0.232 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.84 (d, J = 8.0 Hz, 1H),
7.62 (d, J = 19.2 Hz, 1H), 7.61 (d, J = 8.0 Hz, 1H),
7.47 (t, J = 7.6 Hz, 1H), 7.29 (t, J = 7.6 Hz, 1H), 6.32
(d, J = 19.2 Hz, 1H), 3.89 (s, 3H), 0.99 (t, J = 8.0 Hz,
9H), 0.67 (q, J = 8.0 Hz, 6H). 13C NMR (75 MHz,
CDCl3): d = 168.1, 143.7, 140.5, 131.9, 130.2, 129.6,
128.4, 127.3, 127.2, 52.0, 7.4, 3.5. Anal. Calc. for
C16H24O2Si: C, 69.51; H, 8.75. Found: C, 69.78; H,
1
27b was also observed: H NMR (300 MHz, CDCl3):
d = 5.68 (d, J = 2.8 Hz, 1H), 5.62 (d, J = 2.8 Hz, 1H).
1
8.45%. Before purification 24b was also observed: H
2.4.28. 2-(2-Triethylsilanyl-vinyl)-fluorobenzene (28a)
(Table 3, entry 13) 2-Fluorobromobenzene (0.175 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
NMR (300 MHz, CDCl3): d = 5.60 (d, J = 2.8 Hz, 1H),
5.56 (d, J = 2.8 Hz, 1H). 24c was also observed: 1H
NMR (300 MHz, CDCl3): d = 5.63 (d, J = 17.6 Hz,
1H), 5.34 (d, J = 10.8 Hz, 1H).
1
(1 lmol) gave 28a in 91% (0.215 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.55 (t, J = 7.8 Hz, 1H),
7.19 (m, 1H), 7.11 (d, J = 7.7 Hz, 1H), 7.10 (d, J =
19.2 Hz, 1H), 7.01 (t, J = 7.7 Hz, 1H), 6.48 (d,
J = 19.2 Hz, 1H), 0.98 (t, J = 8.0 Hz, 9H), 0.68 (q,
J = 8.0 Hz, 6H). 13C NMR (75 MHz, CDCl3):
d = 160.1 (d, J = 249.0 Hz), 136.4 (d, J = 4.6 Hz),
129.1, 129.0, 126.6 (d, J = 3.4 Hz), 126.3 (d,
J = 11.5 Hz), 123.9 (d, J = 3.5 Hz), 115.7 (d,
J = 21.8 Hz), 7.4, 3.4. Anal. Calc. for C14H21FSi: C,
71.13; H, 8.95. Found: C, 71.29; H, 8.84%. Before puri-
fication 28b was also observed: 1H NMR (300 MHz,
CDCl3): d = 5.84 (d, J = 2.8 Hz, 1H), 5.70 (d,
J = 2.8 Hz, 1H).
2.4.25. Triethyl-[2-(2-trifluoromethyl-phenyl)-vinyl]-
silane (25a)
(Table 3, entry 8) 2-Trifluoromethylbromobenzene
(0.225 g, 1 mmol), vinyltriethylsilane (0.284 g, 2 mmol),
sodium acetate (0.164 g, 2 mmol), DMF (2 mL) and
Pd complex (1 lmol) gave 25a in 92% (0.263 g) isolated
yield. 1H NMR (300 MHz, CDCl3): d = 7.68 (d,
J = 8.0 Hz, 1H), 7.61 (d, J = 7.8 Hz, 1H), 7.50 (t,
J = 7.6 Hz, 1H), 7.32 (t, J = 7.6 Hz, 1H), 7.26 (d, J =
19.2 Hz, 1H), 6.42 (d, J = 19.2 Hz, 1H), 0.99 (t,
J = 8.0 Hz, 9H), 0.68 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 140.6 (d, J = 2.3 Hz), 138.1 (d,
J = 1.7 Hz), 131.8, 131.7 127.3, 127.1, 127.0 (q,
J = 29.8 Hz), 125.5, (q, J = 5.7 Hz), 124.4 (q, J =
273.6 Hz), 7.3, 3.4. Anal. Calc. for C15H21F3Si: C,
62.90; H, 7.39. Found: C, 62.76; H, 7.51%.
2.4.29. 2-(2-Triethylsilanyl-vinyl)toluene (29a)
(Table 3, entry 17) 2-Bromotoluene (0.171 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
2.4.26. 2-(2-Triethylsilanyl-vinyl)-benzonitrile (26a)
(Table 3, entry 9) 2-Bromobenzonitrile (0.182 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
(4 lmol) gave 29a in 93% (0.216 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.49 (d, J = 7.5 Hz, 1H),
7.18–7.08 (m, 4H), 6.28 (d, J = 19.2 Hz, 1H), 2.36 (s,
3H), 0.97 (t, J = 8.0 Hz, 9H), 0.67 (q, J = 8.0 Hz, 6H).
1
(10 lmol) gave 26a in 72% (0.175 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.69 (d, J = 8.2 Hz, 1H),
7.61 (d, J = 8.2 Hz, 1H), 7.54 (t, J = 7.8 Hz, 1H), 7.33
(t, J = 7.8 Hz, 1H), 7.27 (d, J = 19.2 Hz, 1H), 6.65 (d,
J = 19.2 Hz, 1H), 0.99 (t, J = 8.0 Hz, 9H), 0.70 (q,
J = 8.0 Hz, 6H). 13C NMR (75 MHz, CDCl3):
d = 141.5, 140.1, 133.1, 132.9, 132.6, 127.8, 125.4,
117.8, 111.0, 7.3, 3.3. Anal. Calc. for C15H21NSi: C,
74.01; H, 8.70. Found: C, 73.81; H, 8.57%. Before puri-
fication 26b was also observed: 1H NMR (300 MHz,
CDCl3): d = 5.92 (d, J = 2.8 Hz, 1H), 5.85 (d,
J = 2.8 Hz, 1H).
2.4.30. 4-(2-Triethylsilanyl-vinyl)anisole (30a)
(Table 3, entry 19) 2-Bromoanisole (0.187 g, 1 mmol),
vinyltriethylsilane (0.284 g, 2 mmol), sodium acetate
(0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
(10 lmol) gave 30a in 54% (0.134 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.54 (d, J = 7.6 Hz, 1H),
7.29 (d, J = 19.2 Hz, 1H), 7.22 (t, J = 7.6 Hz, 1H), 6.93
(t, J = 7.6 Hz, 1H), 6.86 (d, J = 8.3 Hz, 1H), 6.38 (d,
J = 19.2 Hz, 1H), 3.84 (s, 3H), 0.98 (t, J = 8.0 Hz, 9H),
0.67 (q, J = 8.0 Hz, 6H). 13C NMR (75 MHz, CDCl3):
d = 156.5, 139.0, 128.9, 127.7, 126.1, 126.0, 120.6,
111.0, 55.5, 7.4, 3.6. Anal. Calc. for C15H24OSi: C,
72.52; H, 9.74. Found: C, 72.41; H, 9.87%. Before puri-
fication 30b was also observed: 1H NMR (300 MHz,
CDCl3): d = 5.76 (d, J = 2.8 Hz, 1H), 5.59 (d,
J = 2.8 Hz, 1H). 30c was also observed: 1H NMR
(300 MHz, CDCl3): d = 5.72 (d, J = 17.6 Hz, 1H), 5.24
(d, J = 11.7 Hz, 1H).
2.4.27. 2-(2-Triethylsilanyl-vinyl)-nitrobenzene (27a)
(Table 3, entry 11) 2-Bromonitrobenzene (0.202 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
(10 lmol) gave 27a in 79% (0.208 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.90 (d, J = 8.1 Hz, 1H),

3798
A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
2.4.31. (2-Anthracen-9-yl-vinyl)-triethylsilane (31a)
(Table 3, entry 21) 9-Bromoanthracene (0.257 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
yield. 1H NMR (300 MHz, CDCl3): d = 8.35 (d,
J = 6.1 Hz, 2H), 7.13 (d, J = 6.1 Hz, 2H), 6.65 (d,
J = 19.2 Hz, 1H), 6.53 (d, J = 19.2 Hz, 1H), 0.76 (t,
J = 8.0 Hz, 9H), 0.50 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 149.6, 145.6, 142.1, 133.0,
120.8, 7.3, 3.2. Anal. Calc. for C13H21NSi: C, 71.17;
H, 9.65. Found: C, 71.38; H, 9.62%. Before purification
1
(10 lmol) gave 31a in 37% (0.118 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 8.33 (s, 1H), 8.31–8.22
(m, 2H), 8.00 (m, 2H), 7.70 (d, J = 19.2 Hz, 1H), 7.50–
7.40 (m, 4H), 6.28 (d, J = 19.2 Hz, 1H), 1.13 (t,
J = 8.0 Hz, 9H), 0.85 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 141.9, 137.3, 135.9, 131.4,
128.7, 128.6, 126.0, 125.9, 125.3, 125.1, 7.6, 3.6. Anal.
Calc. for C22H26Si: C, 82.96;H, 8.23. Found: C, 82.70;
H, 8.27%. Before purification 31c was also observed:
1H NMR (300 MHz, CDCl3): d = 6.01 (d, J = 11.6 Hz,
1H), 5.64 (d, J = 17.7 Hz, 1H).
1
34b was also observed: H NMR (300 MHz, CDCl3):
d = 5.75 (d, J = 2.8 Hz, 1H), 5.50 (d, J = 2.8 Hz, 1H).
34c was also observed: H NMR (300 MHz, CDCl3):
1
d = 5.80 (d, J = 17.6 Hz, 1H), 5.31 (d, J = 10.8 Hz, 1H).
2.4.35. 3-(2-Triethylsilanyl-vinyl)quinoline (35a)
(Table 4, entry 5) 3-Bromoquinoline (0.208 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
2.4.32. Triethyl-[2-(2,4,6-trimethyl-phenyl)-vinyl]silane
(32a)
(1 lmol) gave 35a in 85% (0.229 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 9.03 (s, 1H), 8.07 (m,
2H), 7.79 (d, J = 8.1 Hz, 1H), 7.66 (t, J = 7.4 Hz, 1H),
7.51 (t, J = 7.4 Hz, 1H), 7.03 (d, J = 19.2 Hz, 1H), 6.68
(d, J = 19.2 Hz, 1H), 1.00 (t, J = 8.0 Hz, 9H), 0.71 (q,
J = 8.0 Hz, 6H). 13C NMR (75 MHz, CDCl3):
d = 149.4, 147.6, 141.4, 132.3, 131.1, 129.6, 129.2,
129.1, 128.0, 127.9, 126.8, 7.3, 3.4. Anal. Calc. for
C17H23NSi: C, 75.78; H, 8.60. Found: C, 75.88; H,
(Table 3, entry 22) 2-Bromomesitylene (0.199 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
(4 lmol) gave 32a in 57% (0.148 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 6.92–6.85 (m, 3H), 5.84
(d, J = 19.2 Hz, 1H), 2.39 (s, 3H), 2.28 (s, 6H), 1.02 (t,
J = 8.0 Hz, 9H), 0.69 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 143.8, 137.0, 135.9, 135.1,
131.9, 128.5, 20.9, 20.7, 7.4, 3.5. Anal. Calc. for
C17H28Si: C, 78.38; H, 10.83. Found: C, 78.57; H,
1
8.73%. Before purification 35b was also observed: H
NMR (300 MHz, CDCl3): d = 6.02 (d, J = 2.8 Hz, 1H),
5.77 (d, J = 2.8 Hz, 1H). 35c was also observed: 1H
NMR (300 MHz, CDCl3): d = 5.97 (d, J = 17.6 Hz,
1H), 5.42 (d, J = 10.8 Hz, 1H).
1
10.70%. Before purification 32c was also observed: H
NMR (300 MHz, CDCl3): d = 6.70 (dd, J = 10.8 and
17.6 Hz, 1H), 5.54 (d, J = 10.8 Hz, 1H), 5.25 (d,
J = 17.6 Hz, 1H).
2.4.36. 4-(2-Triethylsilanyl-vinyl)isoquinoline (36a)
(Table 4, entry 7) 4-Bromoisoquinoline (0.208 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
2.4.33. 3-(2-Triethylsilanyl-vinyl)pyridine (33a)
(Table 4, entry 1) 3-Bromopyridine (0.158 g, 1 mmol),
vinyltriethylsilane (0.284 g, 2 mmol), sodium acetate
(0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
(4 lmol) gave 36a in 84% (0.226 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 9.15 (s, 1H), 8.64 (s,
1H), 8.09 (d, J = 8.5 Hz, 1H), 7.97 (d, J = 8.5 Hz, 1H),
7.73 (t, J = 7.8 Hz, 1H), 7.60 (t, J = 7.8 Hz, 1H), 7.51
(d, J = 19.3 Hz, 1H), 6.56 (d, J = 19.3 Hz, 1H), 1.04 (t,
J = 8.0 Hz, 9H), 0.73 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 151.9, 140.6, 139.0, 133.3,
133.0, 131.6, 130.4, 130.2, 128.0, 127.0, 122.8, 7.4, 3.4.
Anal. Calc. for C17H23NSi: C, 75.78; H, 8.60. Found:
C, 75.99; H, 8.55%. Before purification 36b was also ob-
served: 1H NMR (300 MHz, CDCl3): d = 5.99 (d,
J = 2.8 Hz, 1H), 5.92 (d, J = 2.8 Hz, 1H). 36c was also
observed: 1H NMR (300 MHz, CDCl3): d = 5.86 (d,
J = 17.6 Hz, 1H), 5.57 (d, J = 10.8 Hz, 1H).
1
(1 lmol) gave 33a in 86% (0.189 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 8.62 (s, 1H), 8.45 (m,
1H), 7.74 (d, J = 7.9 Hz, 1H), 7.25 (m, 1H), 6.85 (d,
J = 19.2 Hz, 1H), 6.51 (d, J = 19.2 Hz, 1H), 0.96 (t,
J = 8.0 Hz, 9H), 0.67 (q, J = 8.0 Hz, 6H). 13C NMR
(75 MHz, CDCl3): d = 148.7, 148.5, 141.1, 133.8,
132.6, 129.4, 123.4, 7.3, 3.3. Anal. Calc. for C13H21NSi:
C, 71.17;H, 9.65. Found: C, 70.97; H, 9.79%. Before
purification 33b was also observed: 1H NMR
(300 MHz, CDCl3): d = 5.89 (d, J = 2.8 Hz, 1H), 5.66
1
(d, J = 2.8 Hz, 1H). 33c was also observed: H NMR
(300 MHz, CDCl3): d = 5.83 (d, J = 17.6 Hz, 1H), 5.34
(d, J = 10.8 Hz, 1H).
2.4.37. Triethyl-(2-thiophen-2-yl-vinyl)silane (37a)
(Table 4, entry 9) 2-Bromothiophene (0.163 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
(10 lmol) gave 37a in 85% (0.191 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.16 (m, 1H), 7.00–6.92
2.4.34. 4-(2-Triethylsilanyl-vinyl)pyridine (34a)
(Table 4, entry 3) 4-Bromopyridine hydrochloride
(0.195 g, 1 mmol), vinyltriethylsilane (0.284 g, 2 mmol),
sodium acetate (0.246 g, 3 mmol), DMF (2 mL) and
Pd complex (4 lmol) gave 34a in 92% (0.202 g) isolated
1

A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
3799
(m, 3H), 6.15 (d, J = 19.2 Hz, 1H), 0.96 (t, J = 8.0 Hz,
9H), 0.63 (q, J = 8.0 Hz, 6H). 13C NMR (75 MHz,
CDCl3): d = 145.5, 137.3, 127.4, 125.8, 125.4, 124.6,
7.3, 3.4. Anal. Calc. for C12H20SSi: C, 64.22; H, 8.98.
Found: C, 63.97; H, 9.10%. Before purification 37b
was also observed: 1H NMR (300 MHz, CDCl3):
d = 6.09 (d, J = 2.8 Hz, 1H), 6.45 (d, J = 2.8 Hz, 1H).
prove the selectivity of the reaction in favour of the
formation of (E)-triethyl(2-arylethenyl)silane derivatives
a we performed a few coupling reactions using electron-
rich, electron-poor or sterically hindered arylbromides.
In all cases, mixtures of (E)-triethyl(2-arylethenyl)silane
a, triethyl(1-arylethenyl)silane b and styrene derivatives
c were obtained (Table 1, entries 6–10). Then, we studied
the influence of the base for the coupling of 4-t butylb-
romobenzene with vinyltriethylsilane. Disappointing
low selectivities were also obtained using sodium car-
bonate, sodium hydrogen carbonate, cesium carbonate
or potassium fluoride (Table 1, entries 11–14). On the
other hand, a much higher selectivity in favour of the
formation of (E)-4-(2-triethylsilanyl-vinyl)-tert-butyl-
phenyl 6a was observed using sodium acetate as base
(Table 1, entry 15). With this base, using lower reaction
temperatures (100 and 80 °C) high selectivities in favour
or isomer 6a were also obtained, but lower reactions
rates were observed (Table1, entries 16–18). Finally,
the selectivity using two other vinylsilanes derivatives
was studied. Dimethylphenylvinylsilane with four aryl
bromides using sodium acetate as base gave the (E)-dim-
ethylphenyl(2-arylethenyl)silane derivatives 7a–10a with
86–93% selectivities in the presence of 0.4–0.1% catalyst.
Vinyltriphenylsilane using similar reaction conditions
gave no vinylation product (Table 1, entries 19–24).
Hallberg et al. have explained the formation of sty-
rene derivatives for this reaction by desilylation during
the catalytic cycle [5]. After ordinary Heck arylation
on the terminal or internal carbon, an elimination–read-
dition of HPdI followed by desilylation would occur
(Scheme 2). They had observed that in the presence of
silver nitrate this desilylation was suppressed. They as-
sumed that a silver-mediated abstraction of iodide from
the arylpalladium iodide takes place. This intermediate
would form a p alkene–palladium complex from which
the aryl is transferred to the terminal position which is
not prone to desilylation. Then, the (arylethenyl)silane
would be formed after irreversible elimination of a
PdH species.
2.4.38. Triethyl-(2-thiophen-3-yl-vinyl)silane (38a)
(Table 4, entry 11) 3-Bromothiophene (0.163 g,
1 mmol), vinyltriethylsilane (0.284 g, 2 mmol), sodium
acetate (0.164 g, 2 mmol), DMF (2 mL) and Pd complex
1
(10 lmol) gave 38a in 87% (0.195 g) isolated yield. H
NMR (300 MHz, CDCl3): d = 7.30–7.20 (m, 2H), 7.17
(m, 1H), 6.87 (d, J = 19.2 Hz, 1H), 6.18 (d,
J = 19.2 Hz, 1H), 0.97 (t, J = 8.0 Hz, 9H), 0.64 (q,
J = 8.0 Hz, 6H). 13C NMR (75 MHz, CDCl3):
d = 142.3, 138.6, 125.8, 125.6, 124.9, 122.3, 7.4, 3.4.
Anal. Calc. for C12H20SSi: C, 64.22; H, 8.98. Found:
C, 64.00; H, 8.87%. Before purification 38b was also
observed: 1H NMR (300 MHz, CDCl3): d = 6.01 (d,
J = 2.8 Hz, 1H), 5.52 (d, J = 2.8 Hz, 1H). 38c was also
observed: 1H NMR (300 MHz, CDCl3): d = 6.42 (d,
J = 17.6 Hz, 1H), 5.32 (d, J = 10.8 Hz, 1H).
2.8. CAS Registry Nos.: 3a, 327999-88-2; 4a, 327999-
89-3; 5a, 644998-08-3; 11a, 21209-32-5; 14a, 724785-95-
9; 29a, 327999-87-1.
3. Results and discussion
3.1. Influence of the reactions conditions on the selectivity
First, we have investigated the influence of the base,
solvent and substituents on the vinylsilane derivative
on the selectivity of the reaction with our catalyst
(Scheme 1, Table 1). The reactions were performed at
130 °C, under argon, in the presence of a ratio 1/2 of
[Pd(C3H5)Cl]2/tedicyp as catalyst. The results presented
in the Table 1 disclose a strong influence of the reaction
conditions on the selectivity of the reaction. The first
experiments were performed using 4-bromoacetophe-
none, vinyltriethylsilane, potassium carbonate as base
with a few solvents. In the presence of DMF, xylene,
NMP or DMAC the (E)-triethyl(2-arylethenyl)silane
products a were obtained, but the reaction was not selec-
tive and the formation of large amounts of styrene deriv-
atives c was also observed (Table 1, entries 1–4). When
ethylene glycol was used as solvent, no vinylation prod-
uct was observed (Table 1, entry 5). Next, in order to im-
Jeffery [13] had observed that high selectivities in fa-
vour of the formation of (E)-dimethylphenyl(2-arylethe-
nyl)silane derivatives a could also be obtained using
tetra-n-butylammonium acetate as base or in the pres-
ence of a mixture of tetra-n-butylammonium acetate
and potassium acetate instead of silver nitrate.
We believe that with our tetraphosphine/palladium
catalyst in the presence of sodium acetate abstraction
of bromide from the arylpalladium bromide intermedi-
ate to form an arylpalladium acetate and sodium
[PdCl(C3H5)]2
/ 1/2 Tedicyp
Si(R2)3
+
Si(R2)3
+
Br
+
R1
Si(R2)3
R1
R1
R1
base, solvent,
130˚C
1a–30a
1b–30b
1c–30c
Scheme 1.

3800
A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
Ar
Pd
I
I
I
I
[Pd]
Pd
SiR3
Pd
Ar
SiR3
Pd
ArI
+
Ar
R3Si
Ar
Ar
H
SiR3
SiR3
SiR3
Ar
Scheme 2.
AcO
AcO
Pd
Pd
Ar
Ar
SiR3
SiR3
[Pd]
NaOAc
SiR3
SiR3
or
+
+ NaBr
ArBr
Ar
(+) AcO(–)
(+)
AcO(–)
Pd
SiR3
Pd
Ar
Ar
SiR3
Scheme 3.
bromide takes place (Scheme 3). Then, the arylpalla-
dium acetate would lead to an ArCH2CH(SiR3)(P-
dOAc) intermediate. This complex would give the
(arylethenyl)silane rather than to be involved in an elim-
ination–readdition process of HPdOAc.
In order to determine the scope and limitations of the
reaction with triethylvinylsilane and aryl bromides in the
presence of sodium acetate and the tedicyp/palladium
complex; the reaction was applied to several para-substi-
tuted aryl bromides (Table 2), meta- and ortho-substi-
tuted aryl bomides (Table 3) and heteroaryl bromides
(Table 4).
of (E)-triethyl(2-arylethenyl)silane derivatives a were ob-
served with electron-poor (88–98%) and with electron-
rich aryl bromides (84–96%).
3.3. Reaction with meta- and ortho-substituted aryl
bromides
The influence of meta or ortho substituents on the
aryl bromide on the reaction rate is reported in the Ta-
ble 3. As expected very similar TONs were obtained with
the meta-substituted aryl bromides 3-trifluoromethylb-
romobenzene and 3-bromobenzaldehyde than with the
para-substituted substrates (Table 3, entries 1–4).
ortho-Substituents on the aryl bromides generally have
a more important effect on the reactions rates of Heck
reactions [18b]. However, with vinyltriethylsilane high
TONs were obtained in some cases with ortho-substi-
tuted aryl bromides. We observed that the coupling of
methyl 2-bromobenzoate, 2-trifluoromethylbromoben-
zene, 2-fluorobromobenzene, 1-bromonaphthalene or
2-bromotoluene proceeds in the presence of 0.1–0.01%
catalyst (Table 3, entries 6–8 and 13–18). On the other
hand, 2-bromoacetophenone, 2-bromobenzonitrile, 2-
bromonitrobenzene or 2-bromoanisole also gave the ex-
pected adducts, but in the presence of 1–0.4% catalyst
(Table 3, entries 5, 9–12, 19 and 20). In all cases very
high selectivities in favour of the formation of (E)-tri-
ethyl(2-arylethenyl)silane derivatives a were observed
(86–100%).
3.2. Reaction with para-substituted aryl bromides
Several reactions were performed using para-substi-
tuted aryl bromides and vinyltriethylsilane with sodium
acetate as base in DMF. We observed that in most cases
the reaction proceeds very smoothly with high selectivi-
ties in favour of the formation of (E)-dimethylphenyl(2-
arylethenyl)silane derivatives a, moreover, a wide
variety of functional groups are tolerated (Table 2). Sim-
ilar reaction rates were obtained with electron-rich and
electron-poor aryl bromide. For example, turnover
numbers of 7500–10,000 can be achieved with this cata-
lyst for activated substrates such as 4-bromoacetophe-
none, 4-bromobenzaldehyde, 4-bromobenzophenone,
4-bromobenzonitrile
and
4-fluorobromobenzene
(Table 2, entries 3–20). With the deactivated aryl bro-
mides: 4-t butylbromobenzene, 4-bromoanisole and 4-
dimethylaminobromobenzene TONs of 5600, 7400 and
1000 were obtained, respectively (Table 2, entries 24–
27 and 30). This observation seems to indicate that the
oxidative addition of the aryl bromide to the palladium
complex is generally not the rate-limiting step of this
reaction. Similar selectivities in favour of the formation
Next, we tried to evaluate the difference of reaction
rate between mono- and di-ortho-substituted aryl bro-
mides, and we observed that even very hindered aryl
bromides could be coupled efficiently with vinyltrieth-
ylsilane (Table 3, entries 21–23). For example, with
2,4,6-trimethylbromobenzene the expected (E)-tri-
ethyl(2-mesitylethenyl)silane 32a was obtained in 57%

A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
3801
yield and 95% selectivity in the presence of 0.4% cata-
lyst. A much lower selectivity in favour of the formation
of (E)-triethyl(2-anthracenylethenyl)silane 31a was ob-
served with 9-bromoanthracene. With this substrate
the formation of a large amount of 9-vinylanthracene
31c was also obtained. These two sterically congested
di-ortho-substituted aryl bromides gave no traces of
branched isomers b.
reaction, but a poisoning effects of the sulphur atom is
also possible.
4. Conclusion
The Tedicyp–palladium complex provides a conve-
nient catalyst for the reaction of several aryl or heteroa-
ryl bromides with vinylsilanes. In the presence of this
catalyst, the (E)-triethyl(2-arylethenyl)silane adducts a
were obtained selectively in good yields when sodium
acetate was used as base. With several substrates, the
reaction can be performed with as little as 0.01% cata-
lyst. In general, traces of triethyl(1-arylethenyl)vinylsil-
anes b and desilylation products c were also observed.
With other bases such as potassium, sodium or cesium
carbonates, the formation of large amounts of the sty-
rene derivatives was observed. This procedure avoids
the use of expensive silver nitrate or the addition of stoe-
chiometric amounts of ammonium salts as additives. A
wide range of functions such as methoxy, fluoro, acetyl,
formyl, benzoyl, carboxylate, nitro, dimethylamino or
nitrile on the aryl bromide are tolerated. To date, only
a few other ligands have achieved this objective; most
of the other ligands were used with more reactive but
more expensive aryl iodides. These results represent eco-
nomically attractive procedures and due to the high
price of palladium, the practical advantage of such low
catalyst loading reactions can become increasingly
important for industrial processes.
3.4. Reaction with heteroaryl bromides
Palladium chemistry involving heterocycles has its
unique characteristics stemming from the heterocyclesÕ
inherently different structural and electronic properties
in comparison to the corresponding carbocyclic aryl
compounds. Pyridines are p-electron deficient. Thioph-
enes are p-electron excessive. If the oxidative addition
of the aryl halides to the palladium complex is the
rate-limiting step of the reaction with this catalyst, the
reactions should be slower with thiophenes than with
pyridines. Furthermore, palladium(II) possesses strong
thiophilicity. This is reflected in the poisoning effects
of the sulphur atom on some palladium-catalysed reac-
tions. This poisoning effect has also been observed in
the presence of nitrogen atom. For this reason, the posi-
tion of the halide on a heteroaromatic ring has an effect
on the reactions rates.
First, we studied the influence of position of the
bromo substituent on bromopyridines or bromoquino-
lines on the rate of the coupling with vinyltriethylsi-
lane. Due to the electronegativity of the nitrogen
atom, the a position of bromopyridines should be
the most susceptible to the oxidative addition to
Pd(0). In fact, we observed better results for the
coupling of 3- and 4-bromopyridine than with 2-
bromopyridine (Table 4, entries 1–4). The reaction
of 2-bromopyridine with 1% catalyst gave no coupling
product. These results seem to indicate that with the
a-substituted 2-bromopyridine, a possible interaction
between the nitrogen atom and the palladium complex
has a deleterious effect on the reaction. On the other
hand, 3-bromopyridine, 3-bromoquinoline, 4-bromo-
pyridine hydrochloride and 4-bromoisoquinoline gave
the expected vinylation adducts in good yields with
as little as 0.1–0.01% catalyst. The selectivities in fa-
vour of the E isomers a are very high (91–97%).
Traces of the styrene derivatives c were also observed
for some reactions with these substrates.
Acknowledgements
´ ´
We thank the CNRS and the ‘‘Conseil General des
ˆ
Bouches-du-Rhone, Fr’’ for providing financial support.
References
[1] (a) For reviews on the palladium–catalysed Heck reaction see
R.F. Heck, in: B.M. Trost, I. Fleming (Eds.), Comprehensive
Organic Synthesis, vol. 4, Pergamon, Oxford, 1991;
(b) M.T. Reetz, in: S.G. Davies, S.-I. Murahashi (Eds.), Transi-
tion metal catalyzed reactions, Blackwell Sci., Oxford, 1999;
(c) I. Beletskaya, A. Cheprakov, Chem. Rev. 100 (2000) 3009;
(d) N. Withcombe, K.K. Hii (Mimi), S. Gibson, Tetrahedron 57
(2001) 7449;
(e) V. Farina, Adv. Synth. Catal. 346 (2004) 1553.
[2] (a) For examples of efficient catalysts for Heck reaction W.A.
Thiophenes are p-electron-excessive heterocycles.
Oxidative addition to palladium should be slower with
bromothiophenes, than with bromopyridines. 2-Bromo
and 3-bromothiophenes with vinyltriethylsilane led to
the vinylation E adducts 37a and 38a with high selectiv-
ities (92–95%) but with very low TONs of 100 and 140
(Table 4, entries 9–12). With these substrates the oxida-
tive addition is probably the rate-limiting step of the
¨
Herrmann, C. Brossmer, K. Ofele, C. Reisinger, T. Riermeier,
M. Beller, H. Fisher, Angew. Chem., Int. Ed. 34 (1995) 1844;
(b) M. Ohff, A. Ohff, M. Boom, D. Milstein, J. Am. Chem. Soc.
119 (1997) 11687;
(c) D. Albisson, R. Bedford, P.N. Scully, Tetrahedron Lett. 39
(1998) 9793;
(d) D. Bergbreiter, P. Osburn, Y.-S. Liu, J. Am. Chem. Soc. 121
(1999) 9531;
(e) C. Gurtler, S. Buchwald, Chem. Eur. J. 5 (1999) 3107;
¨

3802
A. Battace et al. / Journal of Organometallic Chemistry 690 (2005) 3790–3802
[16] M. Feuerstein, F. Berthiol, H. Doucet, M. Santelli, Org. Biomol.
(f) S. Gibson, D. Foster, D. Eastham, R. Tooze, D. Cole-
Hamilton, Chem. Commun. 8 (2001) 779;
Chem. 1 (2003) 2235.
[17] M. Feuerstein, D. Laurenti, C. Bougeant, H. Doucet, M. Santelli,
Chem. Commun. 4 (2001) 325.
(g) A. Littke, G. Fu, J. Am. Chem. Soc. 123 (2001) 6989;
(h) J.-C. Hierso, A. Fihri, R. Amardeil, P. Meunier, H. Doucet,
M. Santelli, V.V. Ivanov, Org. Lett. 6 (2004) 3473.
[18] (a) M. Feuerstein, H. Doucet, M. Santelli, J. Org. Chem. 66
(2001) 5923;
[3] A. Hallberg, C. Westerlund, Chem. Lett. 12 (1982) 1993.
[4] N.M. Chistovalova, I.S. Akhrem, E.V. Reshetova, M.E. VolÕpin,
Bull. Acad. Sci. USSR Div. Chem. Sci. 33 (1984) 2139.
[5] K. Karabelas, A. Hallberg, J. Org. Chem. 51 (1986) 5286.
[6] M.E. Garst, B.J. McBride, J. Org. Chem. 54 (1989) 249.
[7] K. Nilsson, A. Hallberg, Acta. Chem. Scand. 44 (1990) 288.
[8] Z. Teng, R. Keese, Helv. Chim. Acta 82 (1999) 515.
[9] H. Yamashita, B.L. Roan, M. Tanaka, Chem. Lett. 12 (1990)
2175.
(b) M. Feuerstein, H. Doucet, M. Santelli, Synlett 12 (2001)
1980;
(c) M. Feuerstein, H. Doucet, M. Santelli, Tetrahedron Lett. 43
(2002) 2191;
(d) F. Berthiol, M. Feuerstein, H. Doucet, M. Santelli, Tetrahe-
dron Lett. 43 (2002) 5625;
(e) F. Berthiol, H. Doucet, M. Santelli, Tetrahedron Lett. 44
(2003) 1221;
[10] K. Itami, K. Mitsudo, T. Kamei, T. Koike, T. Nokami, J.-I.
Yoshida, J. Am. Chem. Soc. 122 (2000) 12013.
(f) F. Berthiol, H. Doucet, M. Santelli, Synlett 6 (2003) 841;
(g) I. Kondolff, H. Doucet, M. Santelli, Tetrahedron Lett. 44
(2003) 8487;
[11] K. Itami, T. Nokami, Y. Ishimura, K. Mitsudo, T. Kamei, J.-I.
Yoshida, J. Am. Chem. Soc. 123 (2001) 11577.
(h) F. Berthiol, H. Doucet, M. Santelli, Tetrahedron Lett. 45
(2004) 5633;
[12] N.M. Chistovalova, I.S. Akhrem, V.F. Sizoi, V.V. Bardin, M.E.
VolÕpin, Bull. Acad. Sci. USSR Div. Chem. Sci. 37 (1988) 1039.
[13] T. Jeffery, Tetrahedron Lett. 40 (1999) 1673.
(i) I. Kondolff, H. Doucet, M. Santelli, Synlett 9 (2004) 1561;
(j) I. Kondolff, F. Berthiol, H. Doucet, M. Santelli, J. Organomet.
Chem. 689 (2004) 2786;
[14] T. Jeffery, B. Ferber, Tetrahedron Lett. 44 (2003) 193.
`
[15] D. Laurenti, M. Feuerstein, G. Pepe, H. Doucet, M. Santelli, J.
Org. Chem. 66 (2001) 1633.
(k) M. Lemhadri, H. Doucet, M. Santelli, Tetrahedron 50 (2004)
11533.