Catalytic features of the reaction of oxidative cross-coupling of styrene and hexene-1

Article abstract of DOI:10.1134/S1070427212030159

The reaction of oxidative cross-coupling of styrene and hexene-1 in the medium of ice acetic acid was studied in the presence of various active phases based on palladium deposited on carbon-containing carrying agents, activated carbon, fullerenes, astrale

Full text of DOI:10.1134/S1070427212030159

ISSN 1070-4272, Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 3, pp. 407−412. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © A.S. Grisha, A.V. de Vekki, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 3, pp. 433−439.
ORGANIC SYNTHESIS
AND INDUSTRIAL ORGANIC CHEMISTRY
Catalytic Features of the Reaction
of Oxidative Cross-Coupling of Styrene and Hexene-1
A. S. Grisha and A. V. de Vekki
Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo, Russia
Ivanovo State University of Chemical Engineering, Ivanovo, Russia
e-mail: vnh@mail.obit.ru
Received November 22, 2011
Abstract—The reaction of oxidative cross-coupling of styrene and hexene-1 in the medium of ice acetic acid
was studied in the presence of various active phases based on palladium deposited on carbon-containing carrying
agents, activated carbon, fullerenes, astralenes, and nanotubes.
DOI: 10.1134/S1070427212030159
Earlier [1] it has been shown that in the case of oxida-
tive cross-coupling of styrene and hexene-1 in the me-
dium of ice acetic acid at 110°С and pressure 3 MPa in
the presence of the Pd3Sb/C catalyst the full conversion
of reagents with the 80% selectivity of 1-phenyl-1,3-
octadiene formation can be reached. The choice of the
catalyst nature in this case was dictated by a known and
exclusive feature of palladium complexes to catalyze
cross-coupling reactions [2]. At the same time the ap-
plication of the catalyst containing the active interme-
tallic phase Pd3Sb was caused by sufficient stability and
effectiveness of this system in oxidative acetoxylation
reactions, which are extremely close in realization condi-
tions to the cross-coupling reactions [3].
In view of the fact that the work was aimed at the
one-reactor performing of two reactions, cross-coupling
and acetoxylation, we have also selected various carbon
derivatives, supramolecular structures: fullerenes, as-
tralenes, and nanotubes. In this case it was possible to
expect a certain modification of properties of contacts,
at least due to a more diffusive distribution of an active
phase or to the formation of more active endohedral
structures [5].
Theoretically interest to modificators of palladium
is limited by p-elements of the IIIA–VIA groups. The
fact of a high activity of palladium–tellurium–tungsten
and analogous rhenium compositions for 1,3-butadiene
acetoxylation [3] is practically known, therefore in ap-
plication to the cross-coupling reaction an expanded ex-
perimental study is required. To reduce labor-consuming
practical work and to choose faster a set of effective
catalysts, and also to detect predominant physical fac-
tors responsible for successful operation of contacts, we
have applied the extrapolation forecasting method [6, 7].
Positive results obtained for the cross-coupling reac-
tions on heterogeneous catalysts for the first time have
allowed expanding a search for active components of
contacts based on palladium. Furthermore, the aim of
the work included the study of the effect of the carrying
agent nature on the final product yield, as the restriction
imposed earlier [4] is caused by the exclusive feature of
activated carbon not to inhibit a simultaneously passing
acetoxylation reaction. The inhibiting action of other car-
rying agents was attributed to the capability of contact
components to react withAl2O3, SiO2, etc., which resulted
in destruction of redox pairs like Pd-Sb, Pd-Te, Pd-Sn, Rh-
Bi, Rh-Ga, and others, and thus catalysts became inactive.
The essence of the method (algorithm of the binary
linear qualifier with a zero threshold) consists in searching
hyperplanes separating good objects from poor objects
in the space of recognition criteria (they can be various
physicochemical or structural properties of catalysts).
A position of planes in the space of the criteria is es-
tablished by initial, better experimental, data (training
407

408
GRISHA, DE VEKKI
sample). Knowing a position of the separating plane by
the criteria of experimentally not studied catalysts, it is
possible to determine to which of two classes they refer,
i.e. to predict above or below desirable value there will
be their expected activity or any other target property.
training sample into classes by the above-mentioned val-
ues of the yield and conversion were found in the space
of these criteria.
According to the fulfilled classification, the systematic
forecast of binary catalysts containing palladium as an
active element has been carried out. For each promoter
we determined properties of 50 catalysts containing from
0 up to 100 at% of a platinum group metal with a step
of 2 at%.
In the present case it was accepted conventionally on
the basis of the experimental data [1] that good catalysts
should provide the yield of 1-phenyl-1,3-octadiene higher
than 80 wt % under the standard autoclave loading and the
100% raw material conversion. Thus the basic purpose
of the forecasting consisted in the determination of such
combinations of promoters and compositions of catalysts,
for which it is possible to expect simultaneous realization
of the both conditions.
It follows from the analysis of data for 5000 composi-
tions of catalysts that in the case of palladium contacts it
is hardly possible to obtain catalysts meeting the above
requirements in the case of promoting by a single element
(Fig. 1), as there are no fields of overlapping for composi-
tions satisfying the both criteria: 100% conversion at the
yield of a target product greater than 80%.
As recognition criteria we used theoretically comput-
able characteristics of catalysts [8], which are subdivided
into two groups. The first group consists of probabilities
of various combinations of atoms on the surface of cata-
lysts calculated by combinatorial formulas. The criteria
connected with the electron factor of the contact action
and calculated by a quantum-chemical method fall in the
second group.
For each of ternary systems the forecast was carried
out for 200 catalysts, which correspond to points of
a concentration triangle forming a uniform net (Fig. 2).
In the case of ternary compositions fields of a satisfactory
overlap of criteria for the Pd–Te–Sb and Pd–Sb–Bi sys-
tems were detected. This fact at least points to the absence
of a negative influence of tellurium and bismuth on the
Pd–Sb phase of the catalyst, which seems to be positive at
the following combination of Pd–Sb and Rh–Bi systems
at the realization of the cross-coupling and acetoxylation
reaction in the same reactor.
During mathematical handling of experimental data
we have selected 8 criteria, the most influential in the so-
lution of the problem on hand, from the system including
16 possible criteria (Table 1).
The planes completely separating catalysts from the
Table 1. Indexes of significance of the criteria used for classification of catalysts in relation to the 1-phenyl-1,3-octadiene yield
Index of significance, relative units, at the 1-phenyl-1,3-octadiene
yield as compared to theoretical, %
Criterion
80
85
90
Fraction of centers with a configuration:
АА6a
0.01
0.01
0.01
0.35
0.30
0.01
0.01
0.01
0.45
0.35
0.01
0.01
0.01
0.36
0.41
AA3X3
AX6
Fermi level energy
Charge on a central atom
Energy of adsorption on active centre:
carbon
0.80
0.60
0.86
0.73
0.88
0.80
oxygen
Charge on adsorbed
0.50
0.52
0.51
a Notation ААnХm corresponds to a center containing an active metal atom (A) surrounded by the same atoms and by m promoter atoms (X).
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 85 No. 3 2012

CATALYTIC FEATURES OF THE REACTION OF OXIDATIVE CROSS-COUPLING
409
X2
Fig. 2. Results of the forecast of catalytic properties of ternary
catalysts: (1) Pd-Te-Sb, (2) Pd-Te-Bi.
tion detected earlier [9] between the catalytic activity of
a platinum group atom and the effective positive charge
on palladium in coupled redox systems.
To check the results of the extrapolation forecast, we
have carried out a series of experiments aimed at a con-
Table 2. Oxidative cross-coupling of styrene and hexene-1 on
palladium catalysts. Temperature 100°С, air pressure 3 MPa,
reaction duration 3 h
Selectivity of
Yield of 1-phenyl- 1-phenyl-1,3-octa-
1,3-octadiene, wt % diene formation,
Active phase
%
Pd–Sb
81.0
77.8
75.8
80.4
77.1
74.5
90.0
76.6
74.7
87.3
79.4
83.5
26.0
81.0
77.9
75.7
80.3
77.0
74.5
89.9
76.5
74.6
87.1
79.3
83.4
99.0
Pd–Bi
Pd–Te
Fig. 1. Results of the forecast of catalytic properties of binary
catalysts: compositions depending on Pd yield (at. %) are
contoured by a shaped line, those on Pd conversion (at. %)- by
a solid line. N is the number of an element in the periodic system.
Pd–Ge
Pd–As
Pd–Ga
Pd–Tl
The analysis of the mathematical data handling al-
lowed us to obtain information about dominance of
indexes of significance of the criteria used for classifica-
tion of catalysts.
Pd–In
Pd–Sn
Pd–Te–Sb
Pd–Sb–Bi
Pd–Te–Bi
Pd–Te–W
It follows from Table 1 that the criterion of the en-
ergy of carbon adsorption on an active center exerts the
greatest effect. The energies of oxygen adsorption on an
active center, the charge on adsorbed oxygen, and the
Fermi level energy are arranged further. A significance
of the charge on a central atom agrees with the connec-
Pd–Te–Re
17.4
78.3
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 85 No. 3 2012

410
GRISHA, DE VEKKI
firmation or a refutation of the high efficiency of theo-
retically predicted ternary compositions, and also some
binary compositions, in the cross-coupling of styrene and
hexene-1 (Table 2).
reaction under study and the acetoxylation (the same
coupling reaction) of unsaturated hydrocarbons.
In the following stage of the work it seemed expedi-
ent to study the effect of the carrying agent nature on
catalytic properties of the above-chosen contact, i.e. to
consider a significance of the carbon allotropy. To solve
this problem, we have chosen such carrying agents, as
astralenes, nanotubes, and fullerene С60. The results
obtained (Table 3) point to the fact that the nature of
carbon allotropy definitely influences activity of cross-
coupling catalysts, increasing selectivity of the reaction
by 1.4–3.5%. Moreover, the effect is noticeable at the
formation of catalysts with the use of astralenes with
particles of a polyhedral structure made by flat defect-free
graphite surfaces connected by boundary defect fields of
preferentially pentagonal structure.
An examination of the data of Table 2 allows us to
draw the following conclusions. It is possible to reach a
higher yield of 1-phenyl-1,3-octadiene in the presence
of certain binary compositions than in the presence of
the Pd3Sb system. However, it is difficult to find an
explanation to this fact at the present stage of the study,
as ordinary correlations, for example, with electronega-
tivity of the second elements, were not observed. We
can assume that in this case connection of the catalytic
activity and physical properties of elements entering into
a composition has a more complicated character, i.e. is
multi-parameter. These data agree with the results of the
extrapolation forecast with the only exception for the
Pd–Tl composition.Apparently, this fact can be explained
by an easier electron transfer from thallium on palladium
in the redox-process of autoneogenesis of the initial oxi-
dized palladium form in a catalytic cycle. However the
capability of thallium to catalyze a cross-coupling reac-
tion in the absence of palladium seems more significant,
which should lead at least to the additive effect in the
Pd–Tl system. However the check of this supposition is
hampered by the stoichiometry of the reaction in the pres-
ence of only one of the specified elements. It is curious
that Pb4+ ions are also capable to catalyze this reaction,
which seems to be connected with the well-known lead
poisoning of palladium.
Somewhat greater yield of products of the cross-
coupling reaction with such catalysts, apparently, can be
explained by a greater specific surface area and, hence,
accessibility of contact active centers. Furthermore,
preparation of catalysts using supramolecular structures
often results in the formation of contacts containing
nanostructured active phases, which have either enhanced
reactivity or catalytic properties unknown earlier [10].
The study of kinetics of the reaction of styrene and
hexene-1 cross-coupling has shown that the reaction
order with respect to styrene is zero and with respect to
hexene-1 it comes nearer to one. It means that hexene does
not participate in a limiting stage of the process. Then,
on the basis of common reasons and the published data
on arylation of olefins [2], we can generally present the
reaction mechanism as follows:
The study of ternary compositions (Table 2) gave
results, which also agree with the extrapolation forecast
data. So, two compositions were found, which exhibit
a higher catalytic activity than their separate pairwise
combination with palladium atoms. At the same time no
special catalytic properties of W and Re was revealed in
respect to the cross-coupling despite a similarity of the
Cat + C6H5CH=CH2 ↔ Cat(π-C6H5CH=CH2),
Cat(π-C6H5CH=CH2) ↔ Cat(σ-C6H5CH-CH)- + Н+,
Cat(σ-C6H5CH-CH)- + 1-C6H12 → products + Н+,
Table 3. Effect of the allotropy of carbon-containing carrying agents on Pd3Sb catalytic properties. Temperature 100°С, air
pressure 3 MPa, reaction duration 3 h
Yield of 1-phenyl-1,3-octadiene,
wt %
Selectivity of 1-phenyl-1,3-
octadiene formation, %
Carrying agent
Recuperation activated carbon AR-5
Astralene (stacking of 40-50 graphene sheets)
Nanotubes (armchair structure)
81.0
82.4
84.5
81.0
82.3
84.3
Fullerene С60
82.1
82.0
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 85 No. 3 2012

CATALYTIC FEATURES OF THE REACTION OF OXIDATIVE CROSS-COUPLING
411
2Н+ + ЅО2 → Н2О.
300.152 MHz without additional standards with binding
frequency to a deuterated solvent signal.
In the first stage styrene π-coordination is observed,
and then hydrogen is replaced to form a σ-organometallic
compound. Further a transfer of the styroyl group on hex-
ene-1 occurs probably by the intercalation–detachment
mechanism (the last stage is fast). Air oxygen present in
the reaction medium binds freed protons (from styrene
and olefin) in water, making the reaction irreversible.
The IR spectra were measured on a UR-20 device in
KBr tablets.
Chromatographic analyses were carried on
a “Khrom-42” device with a flame ionization detector
and a glass column 2.5 m × 3 mm with an attachment
filled by 3.5% OV-225 on varaport-30 (100-120 mesh).
Gas carrier was nitrogen (30 cm3 min–1), temperature
raise from 70 up to 230°С according to the program
3 deg min–1, temperature of an evaporator 300°С.
The first stage of the mechanism, alternative to the
mechanism with the primary olefin coordination, was
confirmed by the IR spectrum of the catalyst after its treat-
ment with an equimolar mixture of styrene and hexene-1:
absorption bands characteristic of stretching vibrations
of sp3 hybridized carbon atoms and bending vibrations
of a C–H bond in alkenes were absent from the IR spec-
trum. At the same time absorption bands responsible for
stretching (1490 cm–1) and bending (695 cm–1) vibrations
of the С=С group of chemisorbed styrene and ν(C–H)
were observed in the IR spectrum at 3010–3025 cm–1.
Reactions of oxidative cross-coupling and acetoxyl-
ation were normally carried out in a periodic mode in
a stainless steel autoclave. Into a glass of 0.05 l capacity
30 ml of ice acetic acid, 0.8–0.9 g of a powdery catalyst,
and a rated amount of reagents were loaded; the autoclave
was sealed hermetically, electric heating was switched on,
and after reaching a desired temperature air was fanned
up to necessary pressure, stirring was switched on, and
the experiment was carried out, as a rule, up to exhaustion
of reagents (chromatographic monitoring).
It is assumed [11] that one of coproducts, 1,1'-buta-
1,3-dien-1,4-diylbenzene, formed in the reaction course
(the product of styrene dimerization) is formed also from
the specified organometallic intermediate, however the
presence of an alkene in the reaction zone essentially
suppresses this reaction.
Spectral characteristics of the mixture of geometrical
isomers of (Z,E)-1-phenyl-1,3-octadiene correspond to
the data of [12]: IR spectrum (in a thin layer), cm–1: 1640,
1
1595, 1490, 985. Н NMR spectrum (CDCl3), δ, ppm:
0.89 t (3H, J 7.1), 1.25–1.45 m (4H), 2.05–2.20 m (2H),
5.87 d.t (1H, J 7.1, 15, PhC=C–C=CH), 6.21 d.t (1H,
J 11.2, 11.6, PhC=CH), 6.30 d (1H, J 11.6, PhCH=C),
6.60 d.d (1H, J 11.2, 15, PhC=C–CH=C), 7.15–7.40 m
(5H, arom).
EXPERIMENTAL
The 1Н NMR spectra were recorded on a Bruker-300
device in CDCl3 at a spectrometer working frequency of
Table 4. Main technical characteristics of supramolecular carrying agents
Parameter
Astralenes
99.99
Nanotubes
99.99
Fullerene С60
Carbon content, no less than, %
99.99
Density, g cm–3:
0.6–0.8
2.2
0.6–0.8
2.0–2.1
0.6–0.8
–
bulk
true
Average size, nm:
80–150
20–60
0.2
50
0.342
50
2.5·10–4
1
20–3000
2–4
0.02
–
0.342
200
1.5·10–4
10
10–20
–
0.02
–
particles
pores
Extent of graphitization, no more than
Thermobaric stability (3000°С), no less than, kbar
Interlayer distance, nm
Sorption with respect to ССl4, no less than, mg g–1
Electrical resistance (at 120 Pa), no more than, Ω m
Current density of cold emission (1000 V m–2), no less than, mA cm–2
–
–
2·10–4
–
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 85 No. 3 2012

412
GRISHA, DE VEKKI
Catalysts were prepared by a pretreatment of 10 g
REFERENCES
of AR-5 activated recovery carbon or other carbon-
containing materials with a 15% nitric acid aqueous
solution, evaporating the mixture on a water bath up to
disappearance of a liquid phase. A rated amount of com-
ponents of the contact in the form of nitrates, chlorides,
or oxides was dissolved in a mixture of 30 ml of water,
45 ml of nitric acid, and 25 ml of hydrochloric acid, and
then resulting solution was poured out on 10 g of the
carrying agent and evaporated to dryness. The prepared
catalyst was calcinated in a reactor at 150°С for 1–1.5 h,
then temperature was increased up to 200°С, a hydrogen
current was blown in (10–20 l h–1), and the reduction
was carried out at 500–550°С within 1 h; the reactor was
cooled under the presence of a reducing agent.
1. Grisha, A.S. and de Vekki, A.V., Zh. Prikl. Khim., 2010,
vol. 84, no. 11, pp. 1817–1822.
2. Yatsimirskii, A.K., Oxidative Coupling of Unsaturated
Hydrocarbons and Hetero-Organic Compounds under
the Action of Palladium Complexes, Doctorate (Chem.)
Dissertation, Moscow, 1984.
3. de Vekki, A.V., Catalytic Oxidative Acetoxylation of Un-
saturated Hydrocarbons, Doctorate (Chem.) Dissertation,
St. Petersburg, 1994.
4. de Vekki, A.V., Sovremennye problemy nefteorgsinteza i
neftepererabotki: sbornik nauchnykh trudov (Modern Prob-
lems of Oil Organic Synthesis and Oil Refining: Collection
of Scientific Works), de Vekki, A.V., Ed., St. Petersburg:
Professional, 2009, pp. 69–111.
Carbon-containing carrying agents corresponded to
the characteristics given in Table 4.
5. Sidorov, L.N. and Ioffe, I.N., Soros Obshcheobrazovat.
Zh., 2001, vol. 7, no. 8, pp. 30–36.
6. Ioffe, I.I., Dobrotvorskii,A.M., and Belozerskii, V.A., Usp.
Khim., 1983, vol. 52, no. 3, pp. 402–425.
CONCLUSIONS
(1) The extrapolation forecast by the pattern recogni-
tion method has shown that it is hardly to select a more
effective catalyst than Pd3Sb among binary compositions
of the type palladium-metals of the periodic system
with atomic numbers from 22 up to 80. On the contrary,
among ternary compositions systems with additionally
introduced tellurium can be more active phases.
7. Ioffe, I.I., Reshetov, V.A., and Dobrotvorskii, A.M.,
Geterogennyi kataliz. Fiziko-khimicheskie osnovy (Het-
erogeneous Catalysis. Physicochemical Foundations),
Leningrad: Khimiya, 1985.
8. Dobrotvorskii, A.M. and Belozerskikh, V.A., Abstract of
Papers, X Vsesoyuznoe soveshchanie po kvantovoi khimii
(X All-Union Conf. on Quantum Chemistry), Chernogo-
lovka, 1985, part 2, pp. 134–135.
(2) The study of the effect of carbon allotropy on
catalytic properties of contacts has shown that astralene
(stacking of 40–50 graphene sheets), nanotubes (armchair
structure), and fullerene С60 are more effective carrying
agents than activated carbon.
9. Trushova, N.V., de Vekki, A.V., and Mozzhukhina, T.N.,
Kinet. Katal., 1991, vol. 2, no. 1, p. 239.
10. de Vekki, A.V., Kataliz: teoriya i praktika (Catalysis:
Theory and Practice), St. Petersburg: Professional, 2010.
11. Shue, R.S., J. Am. Chem. Soc., 1971, vol. 93, no.25,
(3) It was shown that chemisorption of styrene, but
not of alkene, takes place in the primary chemical act.
On this basis a preferable mechanism of the oxidative
cross-coupling reaction was proposed.
pp. 7116–7117.
12. Miyaura, N., Yamada, K., Suginome, H., and Suzuki, A.,
J. Am. Chem. Soc., 1985, vol. 107, pp. 972–980.
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 85 No. 3 2012