Nickel catalyzed hydrovinylation of arylethylenes: General method of synthesis of α-arylpropionic acids intermediates

Article abstract of DOI:10.1016/S0040-4020(00)00668-2

The hydrovinylation of arylethylenes catalyzed by [Ni(MeCN)₆][BF₄]₂/AlEt₂Cl/PPh₃ was modulated to obtain 3-aryl-1-butenes in high yields and selectivities. A wide variety of arylethylenes containing electron-donating or electron-withdrawing groups and Lewis basic group, can be hydrovinylated at room temperature and under mild conditions by changing the relative ratios of the three-component catalyst. Similar activities and selectivities were observed for o-, m- and p-substituted styrenes. Also, the hydrovinylation of olefins with substituents in the vinyl fragment, such as α-methylstyrene and indene, can be accomplished. (C) 2000 Elsevier Science Ltd.

Full text of DOI:10.1016/S0040-4020(00)00668-2

TETRAHEDRON
Pergamon
Tetrahedron 56 (2000) 7403–7409
Nickel Catalyzed Hydrovinylation of Arylethylenes: General
Method of Synthesis of a-Arylpropionic Acids Intermediates
†
*
Viviane Fassina, Carolina Ramminger, Marcus Seferin and Adriano L. Monteiro
´
Instituto de Quımica—Universidade Federal do Rio Grande do Sul, Av. Bento Gonc¸alves, 9500 CEP 91-591-970, Porto Alegre, Brazil
Received 19 May 2000; accepted 25 July 2000
Abstract—The hydrovinylation of arylethylenes catalyzed by [Ni(MeCN)6][BF4]2/AlEt2Cl/PPh3 was modulated to obtain 3-aryl-1-butenes
in high yields and selectivities. A wide variety of arylethylenes containing electron-donating or electron-withdrawing groups and Lewis basic
group, can be hydrovinylated at room temperature and under mild conditions by changing the relative ratios of the three-component catalyst.
Similar activities and selectivities were observed for o-, m- and p-substituted styrenes. Also, the hydrovinylation of olefins with substituents
in the vinyl fragment, such as a-methylstyrene and indene, can be accomplished. ᭧ 2000 Elsevier Science Ltd. All rights reserved.
Introduction
enantioselective hydrovinylation of styrene or Lewis basic
vinylarenes was performed by a nickel allyl/organoalu-
minum catalyst, in the presence of a chiral azaphospholene
at low temperatures (Ϫ70ЊC).9 Recently, RajanBabu and
coworkers presented a versatile allyl nickel halide based
catalytic system that performs enantioselective hydrovinyl-
ations of 2-vinyl-6-methoxynaphthalene and other
substrates at Ϫ56ЊC.7a Ceder reported a catalyst able to
codimerize Lewis basic arylethylenes with ethylene.6 We
have worked on a dicationic nickel complex/AlEt2Cl
catalyst for arylethylene hydrovinylation under mild con-
ditions.10 Our system appeared to be active, chemo- and
regioselective when styrene was used as substrate, but
poorly active for substrates with Lewis basic centers.
These initial results encouraged us to proceed on the
optimization of the catalytic system in order to enhance
its activity and its applicability range. In this work we
present our progress using [Ni(MeCN)6][BF4]2/AlEt2Cl/
PPh3 optimized for styrene hydrovinylation and for other
vinylarene substrates.
a-Arylpropionic acids have emerged as an important class
of non-steroidal anti-inflammatory agents over the past two
decades. There are several reports showing considerable
efforts in order to synthesize this class of drugs.1 In par-
ticular, hydrovinylation reaction of arylethylenes have
been investigated most extensively because of the impor-
tance of 3-aryl-1-butenes as potential intermediates for this
drug.2The selective arylethylene hydrovinylation can be
achieved by a catalyst-based reaction, employing a tran-
sition metal complex, especially Ni and Pd, as catalyst.
Catalysts based on Rh3 and Ru4 have also been used, but
they are less selective in 3-aryl-1-butenes. Typically
(h3-allyl) nickel halides activated by Lewis acids,5 cationic
Ni-mesityl complexes6 and (h3-allyl) nickel7or (h3-allyl)
palladium8 halides, where halide anion is abstracted by a
silver salt with a noncoordinating anion, have been applied
in the catalytic arylethylene hydrovinylation reactions.
Several a-aryl propionic acids of pharmaceutical interest
have Lewis basic centers and in some cases only one of
the enantiomers has biological activity. As a special require-
ment for a general method of synthesis of these compounds
the hydrovinylation must tolerate Lewis basic substrates and
the employed catalytic system has to be stereoselective as
well as chemo- and regioselective. Indeed, catalysts that
fulfil these requirements have already been reported. The
Results and Discussion
Styrene hydrovinylation optimization
In our previous report we worked on a [Ni(MeCN)6][BF4]2/
AlEt2Cl catalyst system for arylethylenes hydrovinylation.
In these types of catalysts the alkylaluminum is believed to
play an essential role by forming an initial Ni–C bond and
acting as counterion for the catalytic [Ni–H]ϩ formed.11
After trying several alkylaluminum compounds as cocata-
lysts for the reaction, we concluded that AlEt2Cl could be
used with the best results.
Keywords: nickel; hydrovinylation; a-arylpropionic acids; codimerization;
styrene.
* Corresponding author. Tel.: ϩ55-51-316-6318; fax: ϩ55-51-319-1499;
e-mail: almonte@if.ufrgs.br
Permanent address: Faculdade de Quımica—Pontifıcia Universidade
†
´
´
´
Catolica do Rio Grande do Sul, Av. Ipiranga 6681, CEP 90-619-900,
The catalytically active species is believed to be [Ni–H]ϩ,
Porto Alegre, Brazil.
0040–4020/00/$ - see front matter ᭧ 2000 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(00)00668-2

7404
V. Fassina et al. / Tetrahedron 56 (2000) 7403–7409
Scheme 1.
and several side reactions can be observed in the arylethyl-
ene hydrovinylation. Scheme 1 shows the observed by-
products formed in styrene hydrovinylation reactions.
reaction temperature the styrene polymerization ceases and
we could observe that all the other byproducts appeared in
decreased amounts.
The dimerization of ethylene to yield variable amounts of
butenes catalyzed by the same system has already been
report by us12 and was observed for all the hydrovinylation
runs. Aiming towards chemo- and regioselectivity in
3-phenyl-1-butene (2a), we have to consider (a) the non-
catalyzed styrene thermal polymerization (path A,
Scheme 1), (b) [Ni–H]ϩ catalyzed styrene oligomerization
(path B), (c) the recoordination of 2a to the metallic center
and subsequent hydrovinylation yielding methyl-phenyl-
pentenes (4a) (path C) and (d) 2a isomerization to E- and
Z-2-phenyl-2-butenes (3a) (path D).
The regiochemistry of the [Ni–H]ϩ catalyzed styrene
hydrovinylation to 3-phenyl-1-butene has been explained
in terms of the stability of a cationic h3-benzylic inter-
mediate (5a) (Scheme 2).6,7a In fact it was already reported
that a [Ni(h3-CH2Ph)(PPh3)][PF6] catalyzes the regioselec-
tive styrene oligomerization.13 The increase of the [P]/[Ni]
molar ratio (entries 5 and 6) could also increase the
3-phenyl-1-butene selectivity by stabilizing the inter-
mediate 5a. This apparently also had an effect on the
isomerization of 2a to 3a.
The high activity and selectivity towards 2a are maintained
when larger amounts of styrene compared to the catalyst
amount are employed. For entries 7 and 8 the reactor was
pressurized to around 30 bar and additional ethylene was
added periodically to maintain the pressure above 10 bar.
Pressures higher than 10 bar were applied in order to assure
that ethylene could always be available for hydrovinylation.
This procedure can prevent 3-phenyl-1-butene isomeri-
zation, maintaining the selectivity for the reaction at high
levels. For the entry 8, 22.7 mg (0.047 mmol) of the catalyst
were used to produce 39 g (29.5 mmol) of 3-phenyl-1-
butene (90% isolated yield).
Table 1 shows the optimization of the reaction conditions in
order to achieve the best catalyst performances for the
styrene (1a) hydrovinylation.
It can be seen that all the attempts with PPh3 show total
conversion of styrene and that the selectivity towards
3-phenyl-1-butene is easily improved by changing the
reaction times and temperatures (entries 1–4). By lowering
Table 1. Optimization of the reaction conditions towards 2a (0.1 mmol
[Ni(MeCN)6][BF4]2; Pˆ10 bar; 20 mL CH2Cl2, [Al]/[Ni]ˆ5). Unless
otherwise noted, total conversion of styrene was observed
Chelating diphosphines and aminophosphines have been
shown to be inactive in hydrovinylation reaction.6,7a One
of the claimed reasons for this behavior is that the active
species is believed to contain only one molecule of ligand.5a
In fact, in our conditions no reaction at all was observed
when dppe and ppfa were used in conjunction with the
complexes [(h3-C4H7)Ni(COD)][PF6] and [(h3-C4H7)
PdCl]2/AgBF4.8 In sharp contrast, the catalytic system
described here is active and selective for the hydrovinyl-
ation of styrene. High activity and selectivities in 3-phenyl-
1-butene were observed when [Ni(MeCN)6][BF4]2 was used
in conjunction with AlEt2Cl and a diphosphine (entry 9) or
an aminophosphine (entry 10).
Entry Time (min) Sty/Ni T (ЊC)
L
[L]/[Ni] Yield (%)a
1
2
3
4
5
6
240
60
60
30
60
400
400
400
400
400
400
1500
6600
200
200
50
50
25
25
25
25
25
25
25
25
PPh3
PPh3
PPh3
PPh3
PPh3
PPh3
PPh3
PPh3
dppee
ppfah
2
2
2
2
4
4
4
4
1
1
2
4
20
61
96
98
93
92
96
89
50
7b
8c
9d
10f,g
360
360
75
40
a GC yields.
b Pˆ30 bar.
c Pˆ35 bar, [Al]/[Ni]ˆ8.
d [Al]/[Ni]ˆ20.
Hydrovinylation of styrene derivatives
e dppeˆ1,2-bis-(diphenylphosphino)ethane.
f [Al]/[Ni]ˆ15.
Although our earlier studies using sytrene derivatives
containing Lewis basic centers did not exhibit encouraging
results,10 our current studies present a more versatile system,
g Conversionˆ92%.
h ppfaˆN,N-dimethyl-1-[2-(diphenylphosphino)ferrocenyl]-ethylamine.

V. Fassina et al. / Tetrahedron 56 (2000) 7403–7409
7405
Scheme 2.
capable of performing active and selective styrene hydro-
vinylations. Examining the optimization of the hydrovinyl-
ation of styrene (Table 1) it is evident that it is possible to
improve the reaction performance by working on the cata-
lyst and by tailoring the system composition and reaction
conditions. This feature led us to concentrate our efforts on a
[Ni(MeCN)6][BF4]2/AlEt2Cl/phosphine catalyst capable of
yielding 3-aryl-1-butenes in high yields regardless of the
arylethylene employed as substrate.
without losing selectivity. However, for the styrene deriva-
tives with Lewis basic centers (entries 6–11 in Table 2) this
alternative was not enough. These substrates did not
undergo hydrovinylation reaction using the procedure
described for the other substrates (see Experimental
section). Hence, we decided to change the order of the
addition of the reactants, since we believed this was occur-
ring because the Lewis acid used as cocatalyst could be
reacting with the substrate, precluding formation of the
active species. The hydrovinylation reactions were
performed with high yields and selectivities for this kind
of substrate, by adding AlEt2Cl immediately after the
introduction of the solution of the nickel complex and the
phosphine into the reaction vessel under ethylene atmos-
phere. In terms of reactivity and selectivity, few differences
were observed not only with substituted styrenes containing
The hydrovinylation of styrene derivatives substituted in the
aromatic ring can be accomplished with similar results to
those observed with styrene by changing the [Al]/[Ni] molar
ratio (Table 2). In the case of the alkyl substituted styrene
and vinylnaphthalene, only by increasing the [Al]/[Ni]
molar ratio is it possible to achieve a good catalyst activity
Table 2. Hydrovinylation of arylethylenes (reactions were carried out at room temperature in 20 mL CH2Cl2, 10 bar of ethylene, 0.025 mmol
[Ni(MeCN)6][BF4]2; and [P]/[Ni]ˆ4)
Entry
Substrate
Styrene (1a)
T (min)
[Al]/[Ni]
[subst.]/[Ni]
Conversion (%)a
Sel (%)b
Yield (%)
1
2
60
60
5
5
400
400
100
98
96
86
96c (87)d
84
4-Methylstyrene (1b)
3
30
10
200
100
95
95(68)
4
5
2-Vinylnaphthalene (1d)
Vinylferrocene (1e)
40
45
10
5
100
100
97
100
96
99
93(66)
99(71)
6
60
38
100
100
Ͼ99
99(84)
7
8
9
10
4-Benzoylstyrene (1g)
3-Chlorostyrene (1h)
2-Chlorostyrene (1i)
4-Methoxystyrene (1j)
60
60
60
60
38
7
6
100
400
300
350
100
95
93
88
98
95
95
88(74)
93(75)
88(59)
95(76)
10
100
11
40
20
100
97
99
96(76)
a Determined by GC.
b Selectivity towards 3-aryl-1-buteneˆ3-aryl-1-butene/converted arylethylene.
c GC yield.
d Isolated yields.

7406
V. Fassina et al. / Tetrahedron 56 (2000) 7403–7409
Scheme 3.
substituents in the meta and para (entries 6,7) but also in
meta and ortho (entries 8,9). Vinylferrocene exhibits similar
behavior to styrene and undergoes hydrovinylation in high
yield and selectivity (entry 5).
ethylene–indene codimers. However, only 60% of this
fraction was 1-vinylindane. Further studies have shown
that 1-vinylindane is the initial product and that the hydro-
vinylation catalytic system is also active in the isomeri-
zation of this olefin to internal isomers (Scheme 5). When
higher conversions were obtained (83–100%), the selec-
tivity in ethylene–indene codimers decreased (70–92%) to
some extend but the content of 2m was drastically reduced
(2–30%).
4-Isobutylstyrene, 3-vinylbenzophenone, and 2-methoxy-6-
vinylnaphtalene, all potential precursors for anti-inflamma-
tory agents gave excellent yields of the expected hydro-
vinylation products. We ran the oxidation of 1c according
to the procedure described by us for the Ketoprofen14 using
strong oxidants such as KMnO4 and NaIO4 (Scheme 3). This
procedure affords Ibuprofen in 71% of yield.
Finally, in order to extend the scope of our work we tried the
hydrovinylation of 2-vinylpyridine (1n). In spite of
changing the order of the addition of the reactants or the
[Al]/[Ni] molar ratio, we observed no codimerization
products. Besides the total consumption of the olefin, only
polymerization products were observed.
Substitution at the a- or b-carbons of the styrene generally
leads to poor conversions and yields.15 We are pleased to
find out that by using the catalytic system described here,
a-methylstyrene (1l) was hydrovinylated in moderated
yields (58–68%), which to the best of our knowledge is
the best result described at this point. A considerable
amount of ethylene is consumed in the formation of butenes.
This greater butene formation has already been observed in
other catalytic systems and can be associated with the steric
effect of the methyl fragment. The coordination of the more
hindered double bond at the Ni–H species is more difficult
and consequently the ethylene dimerization to butenes
prevails. We have observed metallic nickel at the end of
these reactions indicating that the species formed with this
olefin should be more unstable than those formed with
styrene. The results are less reproducible probably due to
this instability. For instance, using an Al/Ni ratioˆ15,
a-methylstyrene was consumed in 78–100% with a selec-
tivity in 3,3-methyl-phenyl-1-butene (2l) of 68–74%.
Besides butenes, the only byproducts observed were formed
from the reaction of a-methylstyrene (1l) with two
molecules of ethylene (Scheme 4).
In conclusion, a wide variety of arylethylenes containing
electron-donating or electron-withdrawing groups and
Lewis basic groups, can be hydrovinylated at room tempera-
ture and under mild conditions by changing the relative
ratios of the three-catalyst components and using a suitable
protocol. Similar activities and selectivities were observed
for o-, m- and p-substituted styrenes. Also, the hydrovinyl-
ation of olefins with substituents on the vinyl fragment, such
as a-methylstyrene and indene, can be accomplished. In
opposition to previous catalytic systems, chelating phos-
phines can be used in conjunction with [Ni(MeCN)6][BF4]2
and AlEt2Cl affording good activities and selectivities. The
catalytic activity observed in the presence of chelating phos-
phines opens a possibility to explore the widely available
chiral chelating ligands in the asymmetric hydrovinylation
reaction. This work is now in progress.
Poorer results were found in the indene (1m) hydrovinyl-
ation. The best results obtained were an indene (1m) con-
version of 60% and a very good selectivity of 95% in
Experimental
General
Standard techniques for the manipulation of air-sensitive
compounds were used. Catalytic reactions were carried
out under ethylene pressure in a 100 ml- or 500 ml-stainless
steel autoclave. NMR spectra were recorded on a Varian
VXR-200 or Varian XL 300 spectrometer. Infrared spectra
were recorded on a Bomem B-102 spectrometer. Mass
spectra were recorded on a GC/MS Shimadzu QP-5050
(EI, 70 eV). Gas chromatographic analyses were carried
out on a Varian 3400 CX or HP 5890 GC equipped with a
capillary column L&M — 1 (Polydimethylsiloxane) and
Simplicity-5 (Polydiphenylsiloxane), respectively, using
hydrogen flame ionization detection. Peak areas were
measured by using the internal integration with tetradecane
as the standard and were corrected to accommodate
different detector response factors.
Scheme 4.
Scheme 5.

V. Fassina et al. / Tetrahedron 56 (2000) 7403–7409
7407
Materials
2872, 1632, 1600, 1507, 1453, 1271, 914, 817, 748 cmϪ1
.
GC/MS (EI, 70 eV): m/z (%)ˆ182 (Mϩ, 48), 167 (100), 166
(21), 165 (44), 152 (31), 153 (14), 82 (27). Analytical data:
Calculated: Cˆ92.26%, Hˆ7.74%. Found: Cˆ92.39%,
Hˆ7.84%.
Solvents and reagents were dried over suitable drying agents
and distilled prior to use. Compounds 1a, 1b, 1h, 1i, 1l, 1m,
16
and 1n were purchased from Aldrich. [Ni(MeCN)6][BF4]2
,
1c17 were synthesized as described in the literature.
(1-d,f,g,j,k)18 were prepared by an adapted procedure of a
Heck reaction and 1e by a Wittig reaction.
3-Ferrocenyl-1-butene (2e). Orange oil. Flash chroma-
tography with hexane/dichloromethane (90:10, v/v) as
eluent, 71% yield. 1H NMR (200 MHz, CDCl3, 20ЊC):
dˆ1.22 (d, Jˆ7.0 Hz, 3H), 3.07 (quintet, Jˆ7.1 Hz, 1H),
3.96–4.24 (m, 9H), 4.86–4.96 (m, 2H), 5.81–5.99 (m, 1H).
13C NMR (75.4 MHz, CDCl3, 20ЊC): dˆ21.0 (CH3), 37.4
(CH), 66.7, 66.9, 67.4, 67.5, 68.6 (CHarom), 93.8 (Cq), 112.9
(CH2 olef.), 143.8 (CHolef.). IR(KCl/film) nˆ3093, 2967,
1635, 1453, 1106, 1000, 914, 816 cmϪ1. GC/MS (EI,
70 eV): m/z (%)ˆ240 (Mϩ, 52), 238 (6), 225 (30), 223
(8), 121 (34), 57 (7), 56 (100). Analytical data: Calculated:
Cˆ70.03%, Hˆ6.72%. Found: Cˆ69.91%, Hˆ6.81%.
General procedure for arylethylenes hydrovinylation
3-Phenyl-1-butene (2a).
A solution of 27.3 mg of
[Ni(MeCN)6][BF4]2 (0.057 mmol) and 60.4 mg of PPh3
(0.23 mmol) in 20 mL of dry CH2Cl2 was placed in a
100 mL stainless steel autoclave under argon. Then 2.65 g
(25.44 mmol) of styrene, 0.43 g of tetradecane (internal
standard) and 0.79 mL of AlEt2Cl 0.36 M solution in
toluene were added to the system. The autoclave was closed
and the resulting mixture was stirred at room temperature
for 1 h under 10 bar of ethylene. After releasing the excess
of ethylene, the autoclave was opened and 1 mL of metha-
nol was added. The reaction mixture was distilled using a
bulb to bulb technique (70ЊC, 2 mm Hg) to afford 2.9 g of a
3-Methyl-3-phenyl-1-butene (2l). Colorless liquid.
Kugelrohr distilled (110–120ЊC, 2 mm Hg). 1H NMR
(300 MHz, CDCl3, 20ЊC): dˆ1.49 (s, 6H), 5.11–5.17 (m,
2H), 6.12 (dd, Jˆ11.0 and 16.8 Hz, 1H), 7.23–7.45 (m, 5H).
13C NMR (75.4 MHz, CDCl3, 20ЊC): dˆ28.5 (2CH3), 47.8
(Cq), 110.9 (CH2 olef.), 126.1, 126.4, 128.4 (CHarom), 148.3
(CHolef.) 148.8 (Cq). IR(KCl/film) nˆ3085, 3060, 2967,
1636, 1600, 1494, 1445, 1362, 912, 763, 699 cmϪ1. GC/
MS (EI, 70 eV): m/z (%)ˆ146 (Mϩ, 29), 131 (100), 129
(14), 116 (16), 115 (16), 103 (7), 91 (55), 65(22), 51 (16).
Analytical data: Calculated: Cˆ90.35%, Hˆ9.65%. Found:
Cˆ90.51%, Hˆ9.77%.
1
colorless oil (87%; Ͼ97% pure based upon GC). H NMR
(200 MHz, CDCl3, 20ЊC): dˆ1.37 (d, Jˆ6.9 Hz, 3H), 3.44–
3.49 (m, 1H), 5.01–5.09 (m, 2H), 5.98–6.07 (m, 1H), 7.19–
7.30 (m, 5H). 13C NMR (50.3 MHz, CDCl3, 20ЊC): dˆ20.5
(CH3), 43.1 (CH), 113.0 (CH2 olef.), 126.1, 127.2, 128.4
(CHarom), 143.2 (CHolef.), 145.5 (Cq). IR(KCl/film) nˆ
1638, 1602, 998, 915 cmϪ1. GC/MS (EI, 70 eV): m/z
(%)ˆ132 (Mϩ, 21%), 117 (100), 105 (8), 91 (27), 77 (18),
65 (9), 51 (17), 39 (12). Analytical data: Calculated:
Cˆ90.85%, Hˆ9.15%. Found: Cˆ90.68%, Hˆ9.23%.
3-(3-Benzoylphenyl)-1-butene (2f). A solution of 6.8 mg
of [Ni(MeCN)6][BF4]2 (0.0132 mmol) and 14.8 mg of PPh3
(0.0564 mmol) in 15 mL of dry CH2Cl2 was placed in a
100 mL stainless steel autoclave under argon. Then the
autoclave was purged with ethylene and 0.2 mL of AlEt2Cl
1.8 M solution in toluene was added to the system. The
autoclave was closed and the mixture was stirred at room
temperature for 10 min under ethylene atmosphere. After
this time, a solution of 269 mg of 1f (1.29 mmol) in 5 mL
of dry CH2Cl2 was added and the resulting mixture was
stirred at room temperature for 1 h at 10 bar of ethylene.
After releasing the excess of ethylene, the autoclave was
opened and 1 mL of methanol was added. The reaction
mixture was Kugelrohr distilled (135ЊC, 2 mm Hg) to afford
The following compounds were prepared and isolated in a
similar manner (all compounds were judged to be Ͼ97%
pure based upon GC).
3-(4-Isobutylphenyl)-1-butene (2c). Colorless liquid.
Kugelrohr distilled (90–100ЊC, 2 mm Hg), 68% yield. H
1
NMR (300 MHz, CDCl3, 20ЊC): dˆ0.82 (d, Jˆ6.6 Hz, 6H),
1.28 (d, Jˆ6.9 Hz, 3H), 1.77 (septet, Jˆ6.7 Hz, 1H), 2.37
(d, Jˆ7.1 Hz, 2H), 3.38 (quintet, Jˆ6.8 Hz, 1H), 4.91–5.00
(m, 2H), 5.87–5.99 (m, 1H), 7.02 (AB, Jˆ8.2 Hz, Dyˆ12,
4H). 13C NMR (75.4 MHz, CDCl3, 20ЊC): dˆ20.7 (CH3),
22.4 (2CH3), 30.2 (CH), 42.8 (CH), 45.0 (CH2), 112.8 (CH2
olef.), 126.9, 129.1 (CHarom), 139.4 (Cq), 142.7 (Cq), 143.5
(CHolef.). IR(KCl/film) nˆ3082, 3052, 2957, 2868, 1637,
1512, 1465, 1368, 1017, 912, 844, 797 cmϪ1. GC/MS (EI,
70 eV): m/z (%)ˆ188 (Mϩ, 29%), 189 (Mϩ1, 5) 145 (100),
131 (93), 117 (40), 115 (27), 105 (15), 91 (28), 57 (47).
Analytical data: Calculated: Cˆ89.30%, Hˆ10.70%.
Found: Cˆ89.55%, Hˆ10.76%.
1
239 mg of 2f as colorless oil (80%). H NMR (300 MHz,
CDCl3, 20ЊC): dˆ1.32 (d, Jˆ7.2 Hz, 3H), 3.48 (quintet,
Jˆ6.6 Hz, 1H), 4.96–5.04 (m, 2H), 5.86–6.03 (m, 1H),
6.99–7.83 (m, 9H). 13C NMR (75.4 MHz, CDCl3, 20ЊC):
dˆ20.7 (CH3), 43.0 (CH), 113.8 (CH2 olef.), 128.1, 128.2,
128.4, 128.8, 130.0, 131.4, 132.3 (CHarom), 137.7 (Cq),
142.6 (CHolef.), 145.9 (Cq), 196.8 (CvO). IR(KCl/film)
nˆ3082, 3076, 2965, 1733, 1660, 1598, 1578, 1448,
1282, 915, 715, 701 cmϪ1. GC/MS (EI, 70 eV): m/z
(%)ˆ236 (Mϩ, 22), 159 (27), 131 (80), 105 (100), 91
(15), 77 (66), 51 (22). Analytical data: Calculated: Cˆ
86.41%, Hˆ6.82%. Found: Cˆ86.37%, Hˆ6.89%.
3-(b-Naphthyl)-1-butene (2d). Pale yellow liquid. The
reaction mixture was filtered and the volatiles were removed
under reduced pressure, 66% yield. H NMR (200 MHz,
CDCl3, 20ЊC): dˆ1.36 (d, Jˆ6.8 Hz, 3H), 3.54 (quintet,
Jˆ6.8 Hz, 1H), 4.96–5.15 (m, 2H), 5.91–6.08 (m, 1H),
7.28–7.72 (m, 7H). 13C NMR (50.3 MHz, CDCl3, 20ЊC):
dˆ20.7 (CH3), 43.2 (CH), 113.4 (CH2 olef.), 125.2, 125.3,
125.9, 126.2, 127.5, 127.6, 127.9 (CHarom), 132.2, 133.7,
143.0 (Cq), 143.1 (CHolef.). IR(KCl/film) nˆ3054, 2966,
1
The following compounds were prepared and isolated in a
similar manner.
3-(4-Benzoylphenyl)-1-butene (2g). Pale yellow liquid.

7408
V. Fassina et al. / Tetrahedron 56 (2000) 7403–7409
Kugelrohr distilled (150ЊC, 2 mm Hg), 74% yield. 1H NMR
(200 MHz, CDCl3, 20ЊC): dˆ1.40 (d, Jˆ7.0 Hz, 3H), 3.55
(quintet, Jˆ6.8 Hz, 1H), 5.05–5.14 (m, 2H), 5.93–6.09 (m,
1H), 7.29–7.81 (m, 9H). 13C NMR (75.4 MHz, CDCl3,
20ЊC): dˆ20.5 (CH3), 43.2 (CH), 113.9 (CH2 olef.), 127.1,
128.0, 128.1, 128.4, 129.9, 130.0, 130.1, 130.4, 132.1
(CHarom), 135.5 (Cq), 137.8 (Cq), 142.2 (CHolef.), 150.5
(Cq), 196.3 (CvO). IR(KCl/film) nˆ3082, 3058, 2968,
2872, 1659, 1605, 1447, 1440, 1316, 1279, 851,
702 cmϪ1. GC/MS (EI, 70 eV): m/z (%)ˆ237 (Mϩϩ1,
7%), 236 (Mϩ, 38), 159 (44), 131 (30), 115 (15), 105
(100), 77 (75), 51 (24). Analytical data: Calculated:
Cˆ86.41%, Hˆ6.82%. Found: Cˆ86.58%, Hˆ7.00%.
CDCl3, 20ЊC): dˆ20.7 (CH3), 43.0 (CH), 55.2 (CH3),
105.2(CHarom), 113.2 (CH2 olef.), 118.6, 125.0, 126.7,
126.8, 129.1 (CHarom), 133.2 (Cq), 140.6 (Cq), 143.3
(CHolef.), 157.3 (Cq). IR(KCl/film) nˆ3052, 2963, 2842,
1634, 1605, 1505, 1484, 1266, 1231, 1033, 852,
808 cmϪ1. GC/MS (EI, 70 eV): m/z (%)ˆ212 (Mϩ, 88),
197 (100), 182 (30), 165 (73), 153 (35), 141 (15), 115
(21), 76 (12), 63(14), 51(11). Analytical data: Calculated:
Cˆ84.87%, Hˆ7.60%. Found: Cˆ85.03%, Hˆ7.72%.
a-(4-Isobutylphenyl) propionic acid (Ibuprofen).14 To a
t
solution of 2c (71 mg, 0.38 mmol) in 10 mL of BuOH and
20 mL of water, KMnO4 (185 mg, 1.17 mmol), NaIO4
(1.46 g, 6.86 mmol) and K2CO3 (366 mg, 2.64 mmol)
were added. The pH of the solution was adjusted to 8 with
3 M NaOH aqueous solution and then the reaction mixture
was stirred for 3 h at room temperature. After this time the
pH of the mixture was adjusted to 1 with concentrated HCl
and NaHSO3 was added to reduce MnO2. The mixture was
washed with ether and the ethereal layer was extracted with
3 M NaOH aqueous solution. The aqueous layer was acidi-
fied with concentrated HCl and then extracted with ether.
The organic layer was dried over MgSO4, filtered and the
volatiles were removed under reduced pressure, yielding
Ibuprofen as a white powder (56 mg, 71%). 1H NMR
(300 MHz, CDCl3, 20ЊC): dˆ0.81 (d, Jˆ6.4 Hz, 6H), 1.45
(d, Jˆ6.9 Hz, 3H), 1.76 (septet, Jˆ6.9 Hz, 1H), 2.36 (d,
Jˆ7.2 Hz, 2H), 3.62 (q, Jˆ6.9 Hz, 1H), 7.08 (AB,
Jˆ8.1 Hz, Dyˆ35, 4H). IR(KCl/Nujol mull) nˆ3000–
2500, 1719, 1508, 1462, 1420, 1231, 1184, 780 cmϪ1. GC/
MS (EI, 70 eV): m/z (%)ˆ206 (Mϩ, 45%), 161 (100), 163
(90), 119 (56), 117 (56), 107 (58), 91 (93), 77 (17).
3-(3-Chlorophenyl)-1-butene (2h). Colorless liquid.
1
Kugelrohr distilled (65–75ЊC, 2 mm Hg), 75% yield. H
NMR (200 MHz, CDCl3, 20ЊC): dˆ1.43 (d, Jˆ7.1 Hz,
3H), 3.52 (quintet, Jˆ7.0 Hz, 1H), 5.09–5.19 (m, 2H),
5.96–6.12 (m, 1H), 7.14–7.33 (m, 4H). 13C NMR
(75.4 MHz, CDCl3, 20ЊC): dˆ20.5 (CH3), 42.8 (CH),
113.7 (CH2 olef.), 125.5, 126.2, 127.4, 129.6 (CHarom),
134.1 (Cq), 142.3 (CHolef.), 147.6 (Cq). IR(KCl/film)
nˆ3082, 2970, 2878, 1638, 1596, 1573, 1477, 1421,
1080, 917, 783 cmϪ1. GC/MS (EI, 70 eV): m/z (%)ˆ166
(Mϩ, 26%), 151 (25), 131 (100), 115 (51), 116 (44), 103
(12), 91 (23), 77 (16), 51 (21). Analytical data: Calculated:
Cˆ72.07%, Hˆ6.65%. Found: Cˆ72.30%, Hˆ6.69%.
3-(2-Chlorophenyl)-1-butene (2i). Colorless liquid. Kugel-
1
rohr distilled (50–65ЊC, 2 mm Hg), 59% yield. H NMR
(200 MHz, CDCl3, 20ЊC): dˆ1.26 (d, Jˆ7.0 Hz, 3H), 3.93
(quintet, Jˆ7.1 Hz, 1H), 4.95–5.05 (m, 2H), 5.83–6.00 (m,
1H), 6.97–7.28 (m, 4H). 13C NMR (50.3 MHz, CDCl3,
20ЊC): dˆ19.3 (CH3), 38.8 (CH), 113.9 (CH2 olef.), 126.9,
127.3, 128.1, 129.5 (CHarom), 133.6 (Cq), 141.4 (CHolef.),
142.8 (Cq). IR(KCl/film) nˆ3082, 3064, 2969, 1638,
1590, 1572, 1440, 1410, 1032, 996, 916, 753 cmϪ1. GC/
MS (EI, 70 eV): m/z (%)ˆ166 (Mϩ, 56%), 151 (60), 131
(81), 115 (75), 103 (100), 91 (25), 77 (36), 51 (56). Ana-
lytical data: Calculated: Cˆ72.07%, Hˆ6.65%. Found:
Cˆ71.89%, Hˆ6.57%.
Determination of the structure of 2m
1
The H NMR of a complex mixture of C11H12 and C13H16
isomers resulting of the hydrovinylation of indene (1m)
showed a quartet at 3.75 ppm (Jˆ8.0 Hz), revealing the
presence of 1-vinylindane.15a The mixture of C11H12 and
C13H16 isomers was placed in a stainless steel autoclave
with Pd/C and charged with 10 atm of hydrogen. The
reaction was followed by GC/MS. The hydrogenation of
the C11H12 fraction gave only one product indicating that
1-vinylindane was the former species formed in the hydro-
vinylation reaction.
3-(4-Methoxyphenyl)-1-butene (2j). Colorless liquid.
1
Kugelrohr distilled (75ЊC, 2 mmHg), 76% yield. H NMR
(200 MHz, CDCl3, 20ЊC): dˆ1.33 (d, Jˆ7.0 Hz, 3H), 3.35–
3.52 (m, 1H), 3.78 (s, 3H), 4.97–5.10 (m, 2H), 5.89–6.10
(m, 1H), 6.84 (d, Jˆ8.8 Hz, 2H), 7.13 (d, Jˆ8.8 Hz, 2H).
13C NMR (75.4 MHz, CDCl3, 20ЊC): dˆ20.8 (CH3), 42.3
(CH), 55.2 (CH3), 112.2 (CH2 olef.), 113.8, 128.1 (CHarom),
137.6 (Cq), 143.6 (CHolef.), 157.9 (Cq). IR(KCl/film)
nˆ3076, 3034, 2964, 1632, 1611, 1583, 1247, 1179,
1037, 913, 830 cmϪ1. GC/MS (EI, 70 eV): m/z (%)ˆ161
(MϩϪ1, 11%), 162 (Mϩ, 40), 147 (100), 131 (18), 115
(24), 103 (12), 91 (58), 77 (20), 51 (19). Analytical data:
Calculated: Cˆ81.44%, Hˆ8.70%. Found: Cˆ81.57%,
Hˆ8.65%.
Acknowledgements
The authors acknowledge PADCT-CNPq and FAPERGS
for partial financial support, CAPES (VF), FAPERGS and
CNPq-PIBIC (CR) for fellowships. We are grateful to Dr
John Spencer (UK) for proofreading the manuscript.
References
3-(6-Methoxynaphthyl)-1-butene (2k). Pale yellow liquid.
The reaction mixture was filtered and the volatiles were
removed under reduced pressure, 76% yield. 1H NMR
(300 MHz, CDCl3, 20ЊC): dˆ1.43 (d, Jˆ6.8 Hz, 3H), 3.59
(quintet, Jˆ6.8 Hz, 1H), 3.89 (s, 3H), 5.05–5.11 (m, 2H),
6.05–6.12 (m, 1H), 7.10–7.74 (m, 6H). 13C (75.4 MHz,
1. (a) Rieu, J. P.; Boucherle, A.; Cousse, H.; Mouzin, G.
Tetrahedron 1986, 42, 4095. (b) Sonawane, H. R.; Bellur, N. S.;
Ahuda, J. R.; Kulkarmi, D. G. Tetrahedron: Asymmetry 1992, 3,
163.
2. (a) RajanBabu, T. V. In Comprehensive Asymmetric Catalysis;
Jacobsen, E. N., Pfaltz, A., Yamamoto, H., Eds.; Springer: Berlin,

V. Fassina et al. / Tetrahedron 56 (2000) 7403–7409
7409
1999; pp 417–427. (b) Jolly, P. W.; Wilke, G. In Applied
Homogeneous Catalysis with Organometallic Compounds;
Cornils, B., Hermann, W. A., Eds.; VCH: New York, 1996; Vol.
2, pp 1024.
10. Monteiro, A. L.; Seferin, M.; Dupont, J.; Souza, R. F.
Tetrahedron Lett. 1996, 37, 1157.
11. Wilke, G. The Organic Chemistry of Nickel, Academic Press:
London, 1975; Vol II.
3. Alderson, T.; Jenner, E. L.; Lindsey Jr., R. V. J. Am. Chem. Soc.
1965, 87, 5638.
12. Souza, R. F.; Souza, M. O.; Monteiro, A. L.; Almeida, L.;
Seferin, M.; New J. Chem. 1993, 17, 437.
4. Umezaki, H.; Fujiwara, Y.; Sawara, K.; Teranishi, S. Bull.
Chem. Soc. Jpn 1973, 46, 2230.
13. (a) Ascenso, J. R.; Dias, A. R.; Gomes, P. T.; Roma˜o, C. C.;
Pham, Q.-T.; Neibecker, D.; Tkatchenko, I. Macromolecules 1989,
22, 1000. (b) Ascenso, J. R.; Carrondo, M. A. A. F. C. T.; Dias,
A. R.; Gomes, P. T.; Piedade, M. F. M.; Roma˜o, C. C.; Revillon,
A.; Tkatchenko, I. Polyhedron 1989, 8, 2449.
14. Ramminger, C.; Zim, D.; Lando, V.; Fassina, V.; Monteiro,
A. L. J. Braz. Chem. Soc. 2000, 11, 105.
15. (a) Muller, G.; Ordinas, J. I. J. Mol. Catal. 1997, 125, 97.
(b) Kawata, N.; Maruya, K.; Mizoroki, T.; Osaki, A. Bull. Chem.
Soc. Jpn 1974, 47(2), 413.
5. (a) Wilke, G. Angew. Chem., Int. Ed. Engl. 1988, 27, 185.
(b) Bogdanovic, B. Adv. Organomet. Chem. 1979, 17, 105.
6. Ceder, R.; Muller, G.; Ordinas, J. I. J. Mol. Catal. 1994, 92, 127.
7. (a) Nomura, N.; Jin, J.; Park, H.; RajanBabu, T. V. J. Am. Chem.
Soc. 1998, 120, 459. (b) Nandi, M.; Jin, J.; RajanBabu, T. V. J. Am.
Chem. Soc. 1999, 121, 9899. (c) RajanBabu, T. V.; Nomura, N.;
Jin, J. Chem. Eur. J. 1999, 5, 1963. (d) For heterodimerization of
propylene and vinylarenes see: Jin, J.; RajanBabu, T. V.
Tetrahedron 2000, 56, 2145.
16. Souza, R. F.; Monteiro, A. L.; Seferin, M.; Souza, M. O.;
Stedile, F. C.; Wyrvalsky, C. N.; Baumvol, I. J. R. J. Coord.
Chem. 1996, 40, 311.
¨
8. Bayersdorfer, R.; Ganter, B.; Englert, U.; Keim, W.; Vogt, D.
J. Organomet. Chem. 1998, 552, 187.
9. Wilke, G.; Monkiewicz, J.; Kuhn, H. US Patent 4,912,274,
1990; Chem. Abstr. 1991, 109, 6735.
17. Parrinelo, G.; Stille, J. K. J. Am. Chem. Soc. 1987, 109, 7122.
18. Heck, R. F.; Plevyak, J. E. J. Org. Chem. 1978, 43, 2454.