Efficient functionalization of olefins by arylsilanes catalyzed by palladium anionic complexes

Article abstract of DOI:10.1016/j.molcata.2016.07.023

The coupling of organosilanes and different olefins was performed efficiently in the presence of anionic complexes, [CA]₂[PdX₄] and [CA]₂[Pd₂X₆], where CA?=?imidazolium or pyridinium cation. The reaction proceeds according to a Pd(II)-mediated pathway, and Cu(OAc)₂ acts as the re-oxidant of Pd(0) formed during the catalytic process. High product yields were obtained for differently substituted olefins at 80?°C in 4?h. Styrylsilanes reacted in the same conditions giving unsymmetrical 1,3-dienes.

Full text of DOI:10.1016/j.molcata.2016.07.023

Accepted Manuscript
Title: Efficient functionalization of olefins by arylsilanes
catalyzed by palladium anionic complexes
Author: E. Silarska M. Majchrzak B. Marciniec A.M.
Trzeciak
PII:
S1381-1169(16)30273-4
DOI:
Reference:
http://dx.doi.org/doi:10.1016/j.molcata.2016.07.023
MOLCAA 9957
To appear in:
Journal of Molecular Catalysis A: Chemical
Received date:
Revised date:
Accepted date:
29-4-2016
8-7-2016
11-7-2016
Please cite this article as: E.Silarska, M.Majchrzak, B.Marciniec,
A.M.Trzeciak, Efficient functionalization of olefins by arylsilanes catalyzed
by palladium anionic complexes, Journal of Molecular Catalysis A: Chemical
http://dx.doi.org/10.1016/j.molcata.2016.07.023
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Efficient functionalization of olefins by arylsilanes catalyzed by palladium
anionic complexes
1
2
2
1
E. Silarska , M. Majchrzak , B. Marciniec , A.M. Trzeciak
1University of Wrocław, Faculty of Chemistry, 14 F. Joliot-Curie St., 50-383 Wrocław, Poland
2
Adam Mickiewicz University in Poznań, Faculty of Chemistry, 89b Umultowska St., 61-614
Poznań, Poland
*corresponding author: e-mail: anna.trzeciak@chem.uni.wroc.pl, tel. +48 71 3757253,
fax:+48 71 3282348
1

Graphical abstract
H
Si
R
[
CA] [PdCl ]
2 4
R
Cu(OAc) / TBAF
2
Me
Me
Si
R
R
+
Highlights
Excellent catalytic activity of [CA]
2 4
[PdCl ] and [CA]
2
[Pd
2
Cl ] complexes in
6
functionalization of olefins by arylsilanes
Efficient cross-coupling of olefins with triphenylsilanes in Pd/Cu(OAc)
system.
2
/TBAF
Efficient synthesis of 1,4-diaryl-1,3-butadienes in cross-coupling reaction of
vinylsilanes with olefins.
Abstract
The coupling of organosilanes and different olefins was performed efficiently in the presence
of anionic complexes, [CA] [PdX ] and [CA] [Pd ], where CA = imidazolium or
pyridinium cation. The reaction proceedsaccording to a Pd(II)-mediated pathway, and
Cu(OAc) acts as the re-oxidant of Pd(0) formed during the catalytic process. High product
2
4
2
X
2 6
2
yieldswere obtained for differently substituted olefins at 80 °C in 4 h. Styrylsilanes reacted in
the same conditions giving unsymmetrical 1,3-dienes.
Keywords: palladium; organosilanes; styrylsilanes; 1,4-diarylbuta-1,3- dienes; cross-coupling
2

Introduction
Functionalized olefins bearing aryl groups are ubiquitous structural motifs in natural products,
pharmaceutical and cosmetology intermediates, and organic materials[1–4]. Broad applications
of arylated olefins justify a search for simple and inexpensive but also effective methods of
their synthesis. One of the most studied methods of the synthesis of arylated olefins is the
[
1–6]
Heck reaction
(Fig. 1a), which is a palladium-catalyzed coupling of an olefin and an aryl
halide. Despite its many applications, this reaction has some drawbacks such as the harsh
reaction conditions, the requirement of an inert atmosphere, and the generation of HX as a by-
[
7–8]
product . The formation of HX can be avoided by using arylboronic acid as a source of the
aryl group. In this case, Pd(II) is a catalytically active form. Therefore, the addition of an
oxidizing agent is needed to re-oxidize non-active Pd(0) formed during the reaction.
Recently, we have reported on the arylation of olefins with arylboronic acids catalyzed by
anionic palladium(II) complexes with oxygen as the re-oxidant (Fig. 1b)[16]. This
methodology afforded a variety of aryl-substituted olefins with good-to-excellent yields. We
suggested that the efficient re-oxidation of Pd(II) at the end of each catalytic cycle is the key
step determining the high activity of this system[16]. It can therefore be assumed that not only
arylboronic acids but also other organometalloids could be used as aryl group donors.
Following this thought, here we present an alternative cross-coupling reaction, where
organosilicon compounds effectively serve as versatile coupling partners for olefins. This
interesting reaction has been studied only poorly (Fig. 1c)[9–13]. Organosilicon reagents are
easy to handle and much cheaper than organoboranes or aryl halides, which is an advantage.
On the other hand, it should be noted that some of them can be flammable and potentially
toxic.
In 1998, Mori for the first time reported a palladium-catalyzed Heck-type reaction in which
aryl silanols were coupled with olefins in the presence of a stoichiometric amount of
[
9]
Pd(OAc)
2
.
Recently J.Cheng[10] and T. Mino[11] have reported catalytic palladium systems with aryl
[
11]
[10]
trialkoxysilanes, AgF as a re-oxidant, and hydrazone or 1,10-phenanthroline as ligands
stabilizing palladium. Alternatively, rhodium[12] and iridium[13] catalysts have been tested in
this reaction. Up to now, only organosilicon reagents bearing hydroxyl (silanols,
[
9]
[10–11]
silanetriols) and alkoxyl
groups on the silicon atom have been used as substrates. In
contrast, there is no information about the reactivity of PhR
coupling.
2
SiH compounds in this type of
Interestingly, the palladium-catalyzed reaction of organosilanes with olefins enables the
synthesis of 1,4-disubstituted 1,3-dienes. Only one example of such a coupling has been
[
9]
reported till now, based on the transfer of the styryl group from a silane to an olefin . The
fact that conjugated dienes are present in fluorescent samples[25], dopant emitters in
3

electroluminescent devices[26], optical chromophores[27] and biologically activepheromones[28]
motivates the search for new methods of their synthesis[30–32]
.
Compared with other methods, the cross-coupling of vinylsilanes with different olefins
proceeds with a smaller number of reagents and reaction steps, without arylhalides or a long-
[
32–36]
time reaction
.
Here, we report the application of anionic palladium complexes containing pyridinium and
imidazolium cations as catalysts for a Heck-type reaction of olefins and triphenylsilane and
vinylsilane. The high activity of these complexes in the Suzuki–Miyaura[14–15] and the Heck[16]
reactions allowed us to predict that they can also be suitable catalysts for the coupling of aryl-
and vinylsilanes with olefins.
Results and discussion
Optimization of reaction conditions
In the first step of our studies, we selected the coupling of triphenylsilane with butyl acrylate,
catalyzed by complexes 1a and 1b in DMF, as a model reaction. According to earlier
[10–11]
studies
, the presence of two additives is necessary for the efficient performance of this
reaction. One, the re-oxidant, is needed for the reactivation of catalytically active Pd(II), while
the other one activates the silicon compound. In most cases, fluorides have been used for this
purpose. They coordinate to the silicon atom of the substrate forming pentacoordinated
species which easily leave the phenyl group. Considering these facts, we tested different re-
oxidants and fluorides, and the obtained results are presented in Table 1.
In the Hiyama[17]reaction, silicon compounds were successfully activated by some salts and
inorganic bases. Unfortunately, in the studied system, NaOH (entry 1) was not useful, and the
coupling product was not formed. In the presence of KF (entry 2),conversion to butyl
cinnamate was 32%.Betterresults, 60% conversion, were noted for AgF (entry 3) and for
TBAF (tetrabutylammonium fluoride) (entries 4–14). Unfortunately, AgF also reacted with
the substrate, phenylsilane, forming ca. 40% of triphenylsilane fluoride. This compound was
stable under the reaction conditions and did not react with olefin, lowering the final
conversion.
Following literature examples [16,18–23], Cu(II) species should be considered as palladium re-
oxidants. In accordance with this approach, CuF
conversion was rather low (16%). In further studies, a composition of Cu(OAc)
2
was tested (entry 15); however, the obtained
and TBAF
2
was employed (entries 4–14). When (1a) was used as a catalyst in the amount of 5 mol%, the
conversion increased to 70% (entry 12). The same conversion was achieved using only 3
mol% of (1b) (entry 8). In contrast, attempts to use O as the palladium re-oxidant failed, and
2
the product was not formed (entry 17).
4

It is worth noting that the reaction in our system proceeded much faster than in other systems.
Already after 4 h, practically the whole amount of the product was formed, and no further
prolongation of the reaction time was needed. The data presented in Figure 3 shows that 26%
of butyl cinnamate was formed already after 5 min. Next, the yield of the product increased
slowly to reach 43% after 2 h and 70% after 4 h. Similar yields were noted after a longer time,
2
4 h.
It should be underlined that, positively, the temperature applied here is below 100 °C. In
particular, the monomeric palladium complex 1aefficiently reacted at 80 °C, while 60 °C was
already an optimum temperature for the dimers 1b and 2b (Fig. 4).Very low activity of the
studied systems at temperatures below 40 °C can be explained by the intensive formation of
triphenylsilane fluoride in these conditions. The contribution of this inhibiting process
decreased at higher temperature, and triphenylsilane was not found in the reaction mixture at
6
0 °C.
The effect of the palladium amount is presented in Figure 5. As expected, the conversion
increased with the increase of the palladium amount. Up to 40% conversion was achieved
using 0.5–2.0 mol% of palladium. The monomeric complex 1a formed 50% of the product at
3
mol%, while the same amount of 1balready produced a 70% conversion. Thus, the dimeric
complex 1b appeared more efficient than monomeric 1a at a lower concentration.
Different solvents were tested in reactions catalyzed by two dimeric complexes, 1b and 2b
(Table 2). The best results, ca. 60% conversion, were obtained applying anisole and
dimethyloacetamide. Good conversions, in the 42–52% range, were noted for
N-methylpyrrolidone and dioxane. Those results were, however, worse than in DMF.
Reactions conducted in water and in ethylene glycol did not yield the expected product. That
was caused by the formation of unreactive triphenylsilane fluoride. In addition, a rapid
reduction of Pd(II) to Pd(0) was observed in those solvents leading to the formation of Pd(0)
nanoparticles. These nanoparticles are catalytically active in the Suzuki–Miyaura[37] reaction,
but not in the oxidative Heck coupling.
Testing of palladium(II) precursors
Optimized reaction conditions defined for complexes 1a and 1b were applied for testing other
anionic Pd(II) complexes containing imidazolium or pyridinium cations. For comparison,
commercial palladium species and Pd(0) precursors were also used. All reactions were
conducted at 80 °C in 4h with Cu(OAc) and TBAF additives (Table 3).
2
5

Interestingly, the catalytic activity of anionic complexes strongly depended on the kind of
cation present in the complex. Complexes containing pyridinium cations gave higher
conversion than those with imidazolium cations. There is, however, a difference in the
activity of monomeric and dimeric complexes and imidazolium complexes with dimeric
anions provided significantly higher conversion. The highest conversions were obtained for
+
2
a (69%) and 2b (76%) containing a cppy cation.
On the other hand, an effect of halide was not observed and the same result, 54% of butyl
cinnamate, was obtained for chloride and bromide.
It is interesting to find that Pd(OAc)
2
and Pd(acac) presented a good catalytic activity under
2
the applied reaction conditions illustrated by 50% and 45% conversions. All other precursors
tested were significantly less productive. The lowest conversions were achieved for Pd(0)
precursors,Pd
2
dba forming16% of butyl cinnamate, whereas Pd/PVP being inactive. Analysis
3
of the collected data makes it possible to notice obvious advantages of anionic complexes as
catalysts for the studied reaction. The higher activity of dimeric palladates can be related to
the simultaneous activation of substrates on two palladium centers that are close to each other.
Alternatively, the splitting of halide bridges between palladium ions resulted in the creation of
vacant positions easily available for the substrate.
Scope and limitations
In order to confirm the applicability of the elaborated methodology to other substrates,
reactions were performed with different olefins (Table 4).
In the first series of experiments, butyl acrylate reacted with different organosilicon
compounds (entries 1–5). Triphenylsilanol (entry 1) reacted similarly as triphenylsilane,
described previously, giving a 69% conversion. A slightly lower conversion, ca. 60%, was
obtained when phenylsilanes with alkoxy groups were used (entries 4–5). In contrast,
trimethylphenylsilane was not useful in the studied coupling (entry 2).
Considering the effect of olefin, the highest yield of the product, 78%,was obtained for
allylbenzene (entry 6). Methyl acrylate appeared less reactive than butyl acrylate in the same
conditions (entry 7). The selectivity of the arylation of cyclic olefins depends on the ring size.
Thus, small cyclohexene (entry 8) produced two isomeric products, 1-phenylcyclohexene and
2
-phenylcyclohexene. The second product was formed from the first one after double bond
migration. For bigger cycloheptene, isomerization was not observed; however, a small
6

amount of the diarylation product was formed (entry 11). The contribution of diarylated olefin
increased to 35% in the case of cyclooctadiene (entry 10). For this olefin, the conversion was
the highest, 66%.
Very interesting reactivity was discovered for dimethylsilanes containing phenyl and styryl
[
24]
groups . Both groups were transferred to olefin forming two coupling products and the yield
of unsymmetrical 1,3-diene was always higher (Table 5). This indicates the higher reactivity
of the styryl group than the phenyl one. Using allylbenzene as a substrate made it possible to
obtain 58% of symmetric 1,4-diene.In the reaction of(E)-1-(4-chlorophenyl)-2-
(triethoxysilyl)ethene(entry 7), the product of the homocoupling of the chlorostyryl group was
found besides 1,3-diene obtained by the coupling of the chlorostyryl group with butyl
acrylate.
The synthesis of symmetrical and unsymmetrical 1,4-diarylbuta-1,3-dieneselaborated here
presents an attractive alternative to the earlier-described methods. It is a simple one-step
procedure based on inexpensive and non-toxic substrates, in contrast to two-step Heck–
Hiyama coupling or acetylene dimerization- Suzuki coupling[32]. The only problem that
[36]
should be resolved is reaction selectivity.
Kinetics and the Hg(0) test
To identify the catalytically active forms of palladium, the Hg(0) test was performed. It is a
useful method enabling the determination of the possible contribution of Pd(0) nanoparticles
or other ligandless Pd(0) forms in the catalytic process, based on the amalgam formation[25,26]
In the studied system, the activity of Pd(II) is expected and, consequently, Hg(0) should not
influence the reaction course.
.
In the presence of a 500-fold excess of Hg(0), the reaction produced 53–56% of butyl
cinnamate, independently of the moment of Hg(0) introduction (Table 6). The yield was lower
than in the absence of Hg(0); however, the reaction was not stopped by Hg(0), as expected for
a homogeneously catalyzed process.
Analysis of the product composition for reactions performed in the presence of Hg(0) showed
an increased amount of biphenyl, the product of Ph SiH homocoupling. The formation of up
3
to 50% of biphenyl means that the amount of the substrate available for coupling with olefin
was smaller, and, as a result, the yield of butyl cinnamate decreased.
7

The possible reason for the change of the reaction course could be the reduction of Pd(II) to
Pd(0),which is not active in the coupling of triphenylsilane with olefin under the applied
conditions. At the same time, Pd(0) can catalyze the formation of biphenyl via homocoupling
In fact, TEM analysis of the post-reaction mixture evidenced the presence of Pd(0)
nanoparticles, formed most probably in reaction with Hg(0) (Fig. 6). The control analysis of
Hg(0)-free catalytic systems did not show any nanoparticles.
Conclusions
In conclusion, anionic palladium complexes were employed for the first time for the efficient
synthesis of arylated olefins using arylsilanes as a source of the aryl group. In this new
catalytic system, Cu(OAc) was used as a robust re-oxidant, and TBAF served as an activator
2
for organosilane compounds. According to the designed procedures, electron donating and
electron-withdrawing olefins and a wide array of arylsilanes reacted in good to high yields.
Advantageously, in the elaborated synthetic procedure, harmful aryl halides were eliminated
and formation of HX as a side product was avoided. The system is active at lower
concentration of palladium than these reported previously. Moreover, addition of the ligand
stabilizing palladium was not needed.
We have used for the first time PhR SiH as an arylating agent. Up to now, only organosilicon
2
compounds containing –OH or –OR groups were applied in this type of coupling.
A new, easier and one-step pathway for the synthesis of 1,4-diaryl-1,3-butadienes has been
proposed.
Experimental
All the reactants were obtained from Aldrich, Fluka, or Merck in “for synthesis” or higher
quality and were used as received without further purification or drying.
Dimethylphenylvinylsilane and triethoxyvinylsilane were purchased from Gelest. The
ruthenium a complex - Ru(CO)H(Cl)(PPh
3
3
) was prepared according to procedure described
in literature[
.
38]
All anionic palladium complexes were obtained according to methods described in the
[
14–16]
literature
.
Measurements
1
13
29
H NMR (300 and 500 MHz, 298 K), C NMR (125 and 75 MHz, 298 K) and Si NMR (75
MHz, 298 K) spectra were recorded on a Varian XL 300 MHz spectrometer in CDCl
3
solution. Chemical shifts are reported in  (ppm) with the reference to the residue solvent
8

1
13
29
(
CD
3
Cl) peak for H, C (for styrylsilanes) and to TMS for Si and organic products. The
organic products of the catalytic experiments were analyzed with a GC-Mass Spectrometer
(
(
Hewlett Packard 8452A). Mass spectra of the styrylsilanes were obtained by GC-MS analysis
Varian Saturn 2100T, equipped with a BD-5 capillary column (30 m) and an ion trap
detector. High-resolution mass spectroscopic (HRMS) analyses were performed on an AMD-
4
2
02 mass spectrometer. Thin-layer chromatography (TLC) was made on plates coated with
50 µm thick silica gel (Aldrich and Merck), and column chromatography was conducted
with silica gel 60 (70-230 mesh, Fluka).Experiments with microwave heating were prepared
in a microwave oven (Anton Paar, Monowave 300, monomode, 850 W max.). The power of
the reactorwas automatically adjusteddepending on the reaction temperature.
Typical procedure for the palladium-catalyzed Heck-type reaction with organosilanes
The Heck-type reaction was carried out in a 50 ml Schlenk tube. The solid substrates,
organosilane (0.75 mmol), copper(II) acetate (2 mmol), TBAF (2 mmol), and the palladium
complex (0.02 mmol), were weighted and placed in the Schlenk tube in the air. Next, olefin
(1 mmol) and 5 ml of the solvent were added with a pipette. The reactor was closed with a
rubber plug, and the reaction mixture was stirred in 80 °C. After the given reaction time, the
reactor was cooled down, and the organic products were extracted with 20 ml of diethyl ether.
For better phase separation, 1 ml of water was added. 0.15 ml of mesitylene was added as an
internal standard. The organic products were analyzed using the GC–MS method.
After distillation of the solvent at reduced pressure, the crude product was purified by column
chromatography ( mixture of hexane and ethyl acetate).
Hg(0) test
The oxidative Heck reaction was carried out as described above. After the specified reaction
time, mercury (Hg/Pd=500) was added, and the reaction was continued.
Acknowledgements
Financial support of National Science Centre (NCN, Poland) with grant UMO-
2
014/13/N/ST5/00596 (E.S.) is gratefully acknowledged.
9

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1
1

A
X
R
Pd(0
N2
+
+
R
X=-Cl,-Br,-
B(OH)2
B
R
Pd(II)/O
R
C
SiR`3
R
Pd(II)/ox
F
+
R
`
R = -OMe, -Ph, -OH
Fig 1. Scheme of Heck (A) and Heck-type (B, C) reactions
1
2

[
CA] [PdCl ] and [CA] [Pd Cl ]
x
4
2
2
6
x=1,2
[
CA] =
C H
C H CN
3 6
4
9
H C
N
+
N
9
4
N
N
+
+
[bmpy] [PdCl ] (1a)
[cppy] [PdCl ] (2a)
[bmim] [PdCl ] (3a)
2 4
2
4
2
4
[
bmim] [Pd Cl ] (3b)
[bmpy] [Pd Cl ]
(1b)
2 2 6
[cppy] [Pd Cl ] (2b)
2
2
6
2
2
6
[
bmpy] [Pd Br ] (1c)
2 2 6
CH OC H
NCC H6
C H CN
2
3
7
3
3
6
N
N
N
N
+
+
N
N
+
[
dmiop] [PdCl ]
[
bcpim] [PdCl ] (4a)
2 4
(5a)
2
4
[
HSIMes] [PdCl ] (6a)
2 4
N
N
N
N
+
+
[
[
HIPr] [PdCl ] (10a)
2 4
[
HIMes] [PdCl ] (9a)
2
4
HIPr] [Pd Cl ]
(10b)
2
2
6
Fig. 2 Anionic palladium complexes
1
3

Fig. 3. Kinetic profile of the Heck-type reaction
80
70
60
50
40
30
20
10
0
6
8
0°C
0°C
0
2
3
5
10 15 30 60 120 180 240
czas [min]
3 2
Reaction condition: 0.75 mmol Ph SiH, 1 mmol n-butyl acrylate, 3 mol% complex 1b, 1 mmol Cu(OAc) ,
2
mmol TBAF, 5mL DMF,4h
1
4

Fig. 4. Effect of the temperature on the final yield of the product
80
70
60
50
40
30
20
10
0
2a
2b
1b
23
40
60
80
100
130
0
temperature[ C]
Reaction condition: 0.75 mmol Ph
3
SiH, 1 mmol n-butyl acrylate, 3 mol% complex [Pd], 1 mmol Cu(OAc)
2
,
0
2
mmol TBAF, 5 mL DMF, 80 C, 4h
1
5

Fig.5 Effect of the palladium amount on the reaction course
80
70
60
50
40
30
20
10
0
1
a
b
1
0
.5 0.75 1.0
1.5
2.0
2.5
3.0
4.0
5.0
Pd [mol%]
Reaction condition: 0.75 mmol Ph
DMF, 80 C, 4h
3
SiH, 1 mmol n-butyl acrylate, 1 mmol Cu(OAc)
2
, 2 mmol TBAF, 5 mL
0
1
6

Fig. 6 TEM micrograph of [bmpy]
2
[Pd
2
Cl ] after reaction in the presence of Hg(0)
6
40
30
20
10
0
31
30
16
10
6
3
2
1
1
1
2
3
4
5
6
7
8
9
size [nm]
The Pd(0) nanoparticles were mostly round or elliptical, 4–5 nm in diameter.In addition to
well dispersed small nanoparticles, bigger agglomerates, ca. 20–30 nm, containing Pd-Hg,
were also observed. Thus, the main reason for the lower yield of butyl cinnamate observed in
the presence of Hg(0) is the elimination of catalytically active Pd(II) by its reduction to Pd(0).
1
7

Table 1. Optimization of the reaction conditions of the coupling of triphenylsilane with
n-butyl acrylate catalyzed by 1a and 1b.
[
Pd]
COOBu
Ph SiH
+
COOBu
3
ox., [F-], DMF
Ph
Entry
Time [h]
Pd source
Additive
Cu(OAc)
yield [%]
1
4
1a (3mol%)
1a (3mol%)
1a (3mol%)
1a (3mol%)
1a (3mol%)
1a (3mol%)
1a (3mol%)
1b (3mol%)
1b (5mol%)
1b (3mol%)
1a (3mol%)
1a (5mol%)
1a (3mol%)
1a (5mol%)
1a (3mol%)
1a (3mol%)
1a (3mol%)
2
/ NaOH
0
2
4
Cu(OAc)
AgF
2
/ KF
32
60
50
26
48
54
70
71
67
50
71
68
71
16
11
0
3d)
4a)
5
4
4
Cu(OAc)
Cu(OAc)
Cu(OAc)
Cu(OAc)
Cu(OAc)
Cu(OAc)
Cu(OAc)
Cu(OAc)
Cu(OAc)
Cu(OAc)
Cu(OAc)
2
/ TBAF
2
/ TBAF
2
/ TBAF
2
/ TBAF
2
/ TBAF
2
/ TBAF
2
/ TBAF
2
/ TBAF
2
/ TBAF
2
/ TBAF
2
/ TBAF
1
6
3
7
4
8
4
9
4
1
1
1
1
1
1
1
1
0b)
4
1c)
2
4
4
3
24
24
4
4
5
CuF
CuSO
/ TBAF
2
6
4
4
/ TBAF
7
4
O
2
-
3
Reaction condition: 0.75 mmol Ph SiH, 1 mmol n-butyl acrylate, 1 mmol [Cu], 2 mmol [F ] ,5mL DMF,
0
a)
0
b)
0
c)
d)
8
0 C,4h, Reaction carried out in 130 C , Reaction carried out in 60 C , Microwave heating, During reaction
triphenylsilane fluoride has been obtained
1
8

Table 2.Solvent effect
Conversion for complex: [%]
solvent
1b
75
46
65
52
63
0
2b
76
42
58
46
61
0
dimethylformamide
N-methylpyrrolidone
dimethylacetamide
dioxane
anisole
Ethyleneglycol
toluen
12
10
0
4
THFa)
5
water
0
Reaction condition: 0.75 mmol Ph
TBAF, 5 mL solvent, 80 C, 4h, Reaction carried out in 60 C
3
SiH, 1 mmol n-butyl acrylate, 3 mol% [Pd], 1 mmol Cu(OAc)
2
, 2 mmol
0
a)
0
1
9

Table 3.Effect of palladium source
entry
Pd source
1a
Conversion [%]
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
.
54
70
54
69
76
39
23
25
63
27
66
18
45
29
25
16
0
.
1b
.
1c
.
2a
.
2b
.
4a
.
5a
.
3a
.
3b
0.
1.
2.
3.
4.
5.
6.
7.
8.
9.
0.
1.
2.
3.
10a
10b
9a
6a
PdCl
2
2
PdCl
(cod)
Pd
2
dba
3
Pd/PVP
Pd(acac)
2
45
50
17
34
39
20
Pd(OAc)
2
[Pd(allil)Cl]
2
PdCl
2
2
(PhCN)
2
PdCl
(PPh
3 2
)
Na
2
PdCl
4
Reaction condition: 0.75 mmol Ph
TBAF, 5 mL DMF, 80 C, 4h
3
SiH, 1 mmol n-butyl acrylate, 3 mol% [Pd], 1 mmol Cu(OAc)
2
, 2 mmol
0
2
0

Table 4. Palladium-catalyzed coupling of olefins and organosilicon compounds
[
bmpy] [Pd Cl ]
2 2 6
Ar
PhSiR3
+
R
Cu(OAc) , TBAF, DMF
2
R
0
4
h, 80 C
Entry
1
Ar-SiR
3
olefin
product [%]
yield
%]
[
3
Ph SiOH
Ph
COOBu
COOBu
COOBu
COOBu
COOBu
COOBu
6
1
4
9
2
3
Me
3
PhSi
Ph
Ph
Ph
Si
5
Me
Me
4
5
PhSi(OEt)
3
Ph
Ph
60
61
COOBu
COOBu
COOBu
COOBu
PhSi(OMe)
3
6
7
3
Ph SiH
Ph
Ph
Ph
7
8
Ph
50
COOMe
COOMe
3
Ph SiH
Ph
Ph
2
4
0
1
8
3
Ph SiH
2
1

Ph
Ph
Ph
9
1
Ph
3
SiH
59
Ph
3
3
1
5
0
Ph
3
SiH
Ph
Ph
Ph
11
3
Ph SiH
51a)
Reaction condition: 0.75 mmol[Si] 1 mmololefin, 3 mol% complex 1b, 1 mmol Cu(OAc)
2
, 2 mmol TBAF,
0
a)
5
mL DMF, 80 C, 4h, Also trace amount of diarylation product has been obtained
2
2

Tab. 5 Palladium-catalyzed Heck-type reactions with different olefins and vinylsilicon
compounds
Ar
Me
Ph
[bmpy] [Pd Cl ], Cu(OAc) , TBAF
2 2 6 2
COOBu
COOBu
Si
+
COOBu
Ar
+
Ph
DMF, 4h
Me
product1
product 2
Entry Ar
Product 1
Product 2
1
.
Ph
COOBu
COOBu
Ph
3
0%
-
Ph
Ph
5
0%
2
3
.a)
Ph
Ph
Ph
42%
Ph
-
5
8%
.b)
-Ph
Ph
Ph
Ph
Ph
5
2
%
6
2%
4
.
p-MePh
COOBu
Ph
0%
p-MePh
COOBu
4
6%
COOBu
Ph
6%
p-ClPh
COOBu
COOBu
p-ClPh
1
5
6
.
.
5
3%
COOBu Ph
21%
p-OMePh
p-OMePh
3
5%
2
3

p-ClPh
7
.
p-ClPh
EtO
EtO
COOBu
p-ClPh
Si
p-ClPh
5
0%
OEt
30%
Reaction condition: 1.0 mmol [Si], 1 mmol olefin, 3 mol% complex 1b, 1 mmol Cu(OAc)
2
, 2 mmol TBAF,
0
a)
b)
5
mL DMF, 80 C, 4h, Reaction with allylbenzene as olefin; Reaction with styrene as olefin
2
4

Tab. 6 Mercury test
Hg addend after… 0
5
10
53
20
55
(min)
conversion (%)a)
53
56
Reaction condition: 0.75 mmol Ph
Cu(OAc)
3
SiH, 1 mmol n-butyl acrylate, 3 mol% complex 1b, Hg/Pd= 500, 1 mmol
, 2 mmol TBAF, 5 mL DMF, 80 C, 4h, a) estimated for olefins
0
2
2
5