Phosphine-free catalytic system for the carboxylation of olefins with carbon oxide

Full text of DOI:10.1007/s10631-005-0032-3

Doklady Chemistry, Vol. 401, Part 2, 2005, pp. 59–61. Translated from Doklady Akademii Nauk, Vol. 401, No. 4, 2005, pp. 486–488.
Original Russian Text Copyright © 2005 by Eliseev, Stepin, Bondarenko, Lapidus.
CHEMISTRY
Phosphine-Free Catalytic System for the Carboxylation
of Olefins with Carbon Oxide
O. L. Eliseev, N. N. Stepin, T. N. Bondarenko,
and Corresponding Member of the RAS A. L. Lapidus
Received December 2, 2004
The carboxylation of olefins with carbon oxide in a catalyst (0.5 mol %), NBu4Br or NBu4Cl or their mix-
the presence of palladium catalysts can result in the cor- ture (2 g), an acid (TsOH or 37% aqueous HCl solu-
responding acids. The reaction proceeds under CO tion), and water. Water was added in an amount to reach
pressure and requires an acid promoter [1–3]:
a total content of 500 mol % with respect to the olefin
taking into account the presence of HCl. The reactor
was purged several times with CO, sealed, and kept at
the required constant temperature. Then, CO was
admitted up to the required pressure and the stirrer was
CO, H2O
[Pd]/H3O+
R'
COOH
R'
R'
+
R
R
COOH
R
In particular, the carboxylation of styrenes allows turned on. The pressure in the reactor was maintained
one to obtain the derivatives of hydratropic acid, which automatically with a control valve.After 2 h, the reactor
is a structural fragment of the nonsteroidal anti-inflam- was cooled to ambient temperature and the reaction
matory pharmaceutical ibuprofen and its analogues [4]. mixture was unloaded, extracted with ether, and ana-
lyzed by GLC.
One of the reasons restricting the applicability of
The use of Pd(CH3COO)2 as the catalyst led to high,
up to quantitative, conversion of olefins and high gen-
eral selectivity toward the target carboxylic acids
(table). The reaction with aliphatic olefins in most cases
resulted in more than two isomeric acids. This is due to
the migration of the double bond in the substrate mole-
cule in the presence of strong mineral acids. The result-
ing isomeric olefins also undergo carboxylation.
Primary olefins are the most reactive. Their conver-
sion was 97% and higher, and styrene conversion was
93.5%. The yield of acids was 83–91%. The conversion
of octene-2 was slightly lower (86%) at a total acid
yield of 82%. Tetradecene-7 was the least reactive: its
conversion was 62% at an acid yield of 57%. This fea-
ture, i.e., the decrease in the olefin reactivity as the
number of substituents at the double bond rises, is
explained by steric hindrances at the stage of olefin
coordination to palladium.
this reaction is the necessity to use ligands stabilizing
palladium in solution [5]. Phosphines are the most
widely used ligands. However, they are rather expen-
sive and toxic. Moreover, they gradually decompose
under the reaction conditions. Another problem inher-
ent not only in the carboxylation reactions but also gen-
erally in metal complex catalysis is the necessity to sep-
arate and reuse the homogeneous catalyst. A promising
way to solve this problem is to carry out syntheses in
two-phase systems with the reaction products and the
catalyst being in two liquid phases, polar and nonpolar.
Water usually serves as the polar phase [6]. This
requires the use of water-soluble metal complexes as
the catalysts. When ionic liquids serve as the polar
phases, common complex compounds of Pd, Rh, and
other metals can be used as the catalysts [7, 8]. Informa-
tion on the carboxylation of olefins in the medium of
ionic liquids is extremely limited.A paper is available [9].
When studying the carboxylation of olefins in an
ionic liquid medium, namely, tetrabutylammonium
bromide (TBAB), we found unexpectedly that not only
palladium phosphine complexes but also “ligand-free”
palladium shows high catalytic activity.
The carboxylation of olefins under pressure was car-
ried out in a 50-mL steel reactor equipped with a mag-
netic stirrer. The reactor was heated with an electric fur-
nace. The reactor was charged with an olefin (4 mmol),
We used HCl and TsOH as acid promoters. The
yields of acids are somewhat higher in the presence of
HCl. Thus, upon the carboxylation of decene-1, the
yield of acids was 90.5 and 86% in the presence of HCl
and TsOH, respectively, whereas the carboxylation of
tetradecene-7 led to 57 and 49.5% yields, respectively
(table). The role of the anion of the promoter acid in the
presence of strongly coordinated bromide ion is
unclear. This requires further studies.
On the basis of available literature data, we can sup-
pose that palladium is stabilized in a ionic liquid due to
the formation of 16-electron complexes of type
[NBu4]+[L2PdHal]– [10]. The nature of the halide ion
should affect the catalytic activity of the complex.
Zelinsky Institute of Organic Chemistry,
Russian Academy of Sciences, Leninskii pr. 47, Moscow,
119991 Russia
0012-5008/05/0004-0059 © 2005 Pleiades Publishing, Inc.

60
ELISEEV et al.
Carboxylation of olefins in the presence of Pd(CH3COO)2 in a TBAB medium (P = 5.0 MPa, T = 383 K, 2 h)
Yield of acids, %
Selectivity toward acids, %
Acid
promoter
Conversion,
%
Olefin
α-methyl-
α-methyl-
linear
total
linear
overall
substituted
substituted
Heptene-1
Octene-1
Octene-2
Nonene-1
Decene-1
"
HCl
100
41.8
42.2
14.9
42.4
44.2
41.0
37.6
–
40.0
38.2
42.9
38.4
37.8
34.0
39.8
55.9*
47.5*
42.0
91.1
88.4
81.9
91.1
90.5
86.0
88.9
57.2
49.5
83.0
41.8
42.2
17.3
43.0
44.3
41.6
38.6
–
40.0
38.2
49.8
38.9
37.9
34.5
40.9
90.5*
85.9*
44.9
91.1
88.4
95.0
92.4
90.8
87.2
91.3
92.6
89.5
88.8
"
"
100
86.2
98.6
99.7
98.6
97.4
61.8
55.3
93.5
"
"
TsOH
HCl
"
Hexadecene-1
Tetradecene-7
"
TsOH
HCl
–
–
Styrene**
41.0
43.9
* α-Hexylpelargonic acid.
** Heptane was added to the reaction mixture.
To verify this assumption, we conducted a series of system can be used many times with no loss of activity.
experiments in the presence of tetrabutylammonium
chloride (TBAC) and TBAB–TBAC mixtures of differ-
ent composition. Indeed, the yield of acids upon the
carboxylation of decene-1 turned out to depend on the
content of bromide ion in the system (Fig. 1). The con-
version of olefin in the presence of TBAC was only
15 wt %, and the yield of acids was 12.5%. When
TBAB was added to the system (the total weight of the
ionic liquid was the same), the conversion and the yield
increased, reaching a maximum value at a mole fraction
of Br– of 0.7 (Fig. 1).
After each cycle, the reaction mixture was extracted
with ether. The extract contained the carboxylation
products and the unreacted styrene. The catalyst
remained in the system and retained its activity during
seven or eight runs after the addition of a fresh portion
of styrene, water, and heptane (Fig. 2).
Thus, we showed that the carboxylation of olefins
proceeds in high yields in an ionic liquid medium in the
presence of a Pd catalyst containing no phosphine
ligands. The advantage of the suggested catalytic sys-
tem is the possibility of easy separation of the products
from the catalyst and multiple use of the system.
In the experiments on styrene carboxylation, we
showed that the Pd(CH3COO)2–TBAB–HCl catalytic
%
100
%
80
60
40
20
0
Styrene conversion
Acid yield
80
60
Conversion
Acid yield
40
20
0
20
40
60
80
100
–
1
2
3
4
5
6
7
8
Mole fraction of Br in the ionic liquid
Cycle
Fig. 2. Multiple use of the catalytic system for styrene
carboxylation.
Fig. 1. Carboxylation of decene-1 in a TBAB–TBAC mixture.
DOKLADY CHEMISTRY Vol. 401 Part 2 2005

PHOSPHINE-FREE CATALYTIC SYSTEM FOR THE CARBOXYLATION
61
5. Gulevich, Yu.V., Bumagin, N.A., and Beletskaya, I.P.,
REFERENCES
Usp. Khim., 1988, vol. 57, no. 4, pp. 529–561.
1. Mullen, A., in New Synthesis with Carbon Monoxide,
6. Bertiux, F., Monflier, E., Castanet, Y., and Morteux, A.,
Falbe, J., Ed., Berlin: Springer, 1980, p. 243.
J. Mol. Catal. A: Chem., 1999, vol. 143, pp. 11–22.
7. Gordon, C.M., Appl. Catal. A: Gen., 2001, vol. 222,
2. Hohn,A., in Applied Homogeneous Catalysis with Orga-
nometallic Compounds, Cornils, B. and Herrmann, W.A.,
Eds., Weinheim: VCH, 1996, p. 138.
pp. 101–117.
8. Olivier-Bourbigou, H. and Magna, L., J. Mol. Catal. A:
Chem., 2002, vol. 182–183, p. 419.
3. Lapidus, A.L. and Pirozhkov, S.D., Usp. Khim., 1989,
9. Zim, D., de Souza, R.F., Dupont, J., and Monteiro, A.L.,
vol. 58, no. 2, pp. 197–233.
Tetrahedron Lett., 1998, vol. 39, no. 39, pp. 7071–7074.
4. Rieu, J.-P., Boucherle, A., Cousse, H., and Mouzin, G., 10. Calo, V., Giannoccaro, P., Nacci, A., and Monopoli, A.,
Tetrahedron, 1986, vol. 42, no. 15, pp. 4095–4131.
J. Organomet. Chem., 2002, vol. 645, pp. 152–155.
DOKLADY CHEMISTRY Vol. 401 Part 2 2005