Hydroformylation of 2,5-norbornadiene in organic/aqueous two-phase system and acceleration by cationic surfactants

Article abstract of DOI:10.1002/aoc.3436

The organic/aqueous biphasic hydroformylation of 2,5-norbornadiene (NBD) was investigated for the first time using HRh(CO)(TPPTS)₃ (TPPTS: trisodium salt of tri(m-sulphonylphenyl)phosphine) as the catalyst precursor. A comparison was made of homogeneous and biphasic systems. The optimum reaction parameters are discussed and the reaction mechanism is presented. In order to ensure the process attained high activity under moderate conditions, the effect of various cationic surfactants was tested in the biphasic hydroformylation of NBD. The results indicated that the hydroformylation of NBD in the biphasic system exhibited high activity and high selectivity to dialdehyde products under mild conditions. The addition of cationic surfactants markedly accelerated the reaction. A single long-chain surfactant seemed to exert a greater impact on the hydroformylation of NBD than a double long-chain surfactant. Moreover, the recycling of aqueous solution containing catalyst with or without surfactant was investigated. In the absence of the surfactant, the aqueous catalyst could be recycled six times without a significant decrease in activity and selectivity.

Full text of DOI:10.1002/aoc.3436

Full paper
Received: 30 September 2015
Revised: 15 December 2015
Accepted: 21 December 2015
Published online in Wiley Online Library: 8 February 2016
(wileyonlinelibrary.com) DOI 10.1002/aoc.3436
Hydroformylation of 2,5-norbornadiene in
organic/aqueous two-phase system and
acceleration by cationic surfactants
a
b
a
a
a
Xi Yang , Haoran Liang , Haiyan Fu , Xueli Zheng , Maolin Yuan ,
a
a
Ruixiang Li and Hua Chen *
The organic/aqueous biphasic hydroformylation of 2,5-norbornadiene (NBD) was investigated for the first time using HRh(CO)
(
TPPTS) (TPPTS: trisodium salt of tri(m-sulphonylphenyl)phosphine) as the catalyst precursor. A comparison was made of homo-
3
geneous and biphasic systems. The optimum reaction parameters are discussed and the reaction mechanism is presented. In order
to ensure the process attained high activity under moderate conditions, the effect of various cationic surfactants was tested in the
biphasic hydroformylation of NBD. The results indicated that the hydroformylation of NBD in the biphasic system exhibited high
activity and high selectivity to dialdehyde products under mild conditions. The addition of cationic surfactants markedly acceler-
ated the reaction. A single long-chain surfactant seemed to exert a greater impact on the hydroformylation of NBD than a double
long-chain surfactant. Moreover, the recycling of aqueous solution containing catalyst with or without surfactant was investi-
gated. In the absence of the surfactant, the aqueous catalyst could be recycled six times without a significant decrease in activity
and selectivity. Copyright © 2016 John Wiley & Sons, Ltd.
Keywords: 2,5-norbornadiene; biphasic hydroformylation; water-soluble phosphine rhodium complex; surfactants; high added value
troublesome, since the dialdehyde products have a high boiling
point of 280°C. Hence, the separation of products from catalyst
Introduction
With a production of approximately 12 million tons per year, the
hydroformylation of olefins (also named the oxo process) is gener-
ally recognized as one of the most significant catalytic reactions.
in the homogeneous catalysis method would undoubtedly cause
a loss of catalyst.
[
1]
Our group has long been interested in organic/aqueous
biphasic hydroformylation owing to its superiority in terms of
easy separation of the costly catalyst from the products after
the reaction. Also, using water as solvent is environmentally
The products of this reaction and their derivatives are widely used
in the synthesis of plasticizers, pharmaceutical intermediates and
[2]
many other fine chemicals.
[
19,20]
Recently, much attention has been concentrated on the
hydroformylation of special olefins because of its high added
friendly and green.
Therefore, we tried to use a moderate
organic/aqueous biphasic process to conduct the hydroformylation
[
3–14]
value in the manufacture of fine chemicals.
Thus, the
of NBD using HRh(CO)(TPPTS) –TPPTS (TPPTS: trisodium salt
3
hydroformylation of 2,5-norbornadiene (NBD) is of interest,
since the carboxylated derivatives of its dialdehyde products
are applied in the manufacture of advanced photoelectron
of tri(m-sulphonylphenyl)phosphine) as catalyst. In the work
reported here, the effect of reaction conditions was fully inves-
tigated for the biphasic hydroformylation of NBD and the
reaction mechanism was investigated. Since the poor water
solubility of NBD made it hard for it to contact the catalyst in
the aqueous phase, also the effect of cationic surfactant was
studied in the biphasic hydroformylation of NBD, inspired by
[
15]
instruments.
Additionally, NBD is a very intriguing alkene
on account of its unique stereochemical structure and its ability
[
16]
to form stable complexes with rhodium metal.
The unconju-
gated two internal double bonds can allow the production
of mono- and diformyl derivatives (Scheme 1). Monoaldehydes
are mixtures of exo- and endo-aldehydes while dialdehydes are
mixtures of 2,5- and 2,6-dialdehydes. Saus et al. reported the
photochemical hydroformylation of NBD catalyzed by HRhCO
[
21–24]
our previous work.
(
PPh
3 3 3
) –PPh , which suggested that 95% conversion was
*
Correspondence to: Hua Chen, Key Laboratory of Green Chemistry and
Technology of Ministry of Education, College of Chemistry, Sichuan University,
Chengdu 610064, Sichuan, China. E-mail: scuhchen@163.com
achieved only when the reaction pressure reached 8.0 MPa
and a long reaction time of 50 h was required.
[
17]
Later, homo-
geneous hydroformylation of NBD using the same catalyst pre-
cursor gave an excellent result while the reaction pressure was
a Key Laboratory of Green Chemistry and Technology of Ministry of Education,
College of Chemistry, Sichuan University, Chengdu 610064, Sichuan, China
[
18]
as high as 10.0 MPa.
In addition to the harsh requirements
being totally unfavorable for industrialized manipulation, the
separation process for products and catalyst would also be
b College of Chemical Engineering, Sichuan University, Chengdu 610064, Sichuan,
China
Appl. Organometal. Chem. 2016, 30, 335–340
Copyright © 2016 John Wiley & Sons, Ltd.

X. Yang et al.
Table 1. Hydroformylation of NBD in biphasic and homogenous
systems
c
d
Entry Catalyst
Conversion (%)
Selectivity (%)
Monoaldehydes Dialdehydes
Scheme 1. Hydroformylation of 2,5-norbornadiene (NBD).
a
1
2
Rh–TPPTS
51.7
31.0
12.8
25.6
86.0
73.3
b
Rh–TPP
Experimental
a
À4
À1
Reaction conditions: [HRh(CO)(TPPTS)
O, [TPPTS]/[Rh] = 50 (molar ratio), NBD = 0.5 ml (4.9 mmol), toluene
1.5 ml, 70°C, 2.0 MPa, 120 min.
3
] = 6.1 × 10 mol l in 2 ml of
Materials and instrumentation
H
2
[
25]
The catalyst precursor HRh(CO)(TPPTS)
3
,
the water-soluble ligand
b
À4
À1
[
25]
3
Reaction conditions: [HRh(CO)(TPP) ] = 6.1 × 10 mol l in 2 ml of
TPPTS
(
and the surfactants docosyltrimethylammonium iodide
didodecyldimethylammonium bromide (DDMAB),
[
26]
[26]
toluene, [TPP]/[Rh] = 50 (molar ratio), NBD = 0.5 ml (4.9 mmol), 70°C,
2.0 MPa, 120 min.
DTAI),
[26]
cetyldodecyldimethylammonium bromide (DCDAB) and dicetyl-
c
[
26]
Conversion of NBD based on GC.
dimethylammonium bromide (DCMAB) were prepared according
to the literature and their structures were confirmed by comparing
d
Selectivity of mono- or dialdehydes.
1
31
their H NMR and P NMR spectra with those of the literature.
NBD (Alfa), dodecyltrimethylammonium bromide (DTAB; Sigma),
cetyltrimethylammonium bromide (CTAB; Sigma) and cetylpridinium
chloride monohydrate (CPC; Alfa) were commercially obtained and
used without purification. Distilled and deionized water was used
in all experiments. Hydrogen (99.9%) and carbon monoxide (99.0%)
were premixed with a pressure ratio of 1 to 1.
hydroformylation of NBD in the biphasic system proceeds much
better than that in the homogeneous system. It has a higher reac-
tion rate and selectivity to dialdehydes, which led us to investigate
the reaction mechanism of the biphasic NBD hydroformylation.
The hydroformylation products were analyzed using GC with an
Agilent 6890 equipped with a flame ionization detector and a
capillary column (CP-SIL 5cb, 25 m × 0.53 mm). The products were
identified using GC–MS. The rhodium content in the solution was
determined using inductively coupled plasma (ICP) atomic emis-
sion spectrometry with an IRIS Advantage.
Mechanism of NBD hydroformylation
Since final products are a mixture of monoaldehydes and
dialdehydes, the variation in the reaction time was investigated.
The results show that the reaction time exerts a very great impact
on the substrate conversion, and also affects the product distribu-
tion (Table 2). As the reaction time increases from 0.5 to 7.0 h, the
conversion increases dramatically from 9.9 to 99.9%.
Hydroformylation and catalytic recycling
However, it is worth noting that the selectivity of monoaldehydes
and dialdehydes changes following a reverse trend with increasing
conversion. The monoaldehyde selectivity decreases quickly, and,
at its expense, the selectivity of dialdehydes increases to dominate
the ratio. In addition, even for a reaction time as short as 0.5 h,
where only 9.9% of NBD is converted to aldehydes, the selectivity
of dialdehydes still reaches 40.6%. This phenomenon might indi-
cate that dialdehydes are more easily formed from monoaldehyde
and that the two double bonds of NBD are not simultaneously
hydroformylated. The mechanism is supposed to be that the NBD
firstly reacts with syn-gas to form monoaldehydes which are then
converted into dialdehydes. The detailed mechanism is shown in
Fig. 1, referring to the well-known hydroformylation kinetics and
mechanism of ordinary olefins.
The hydroformylation was carried out in a 60 ml stainless steel
autoclave with a magnetic stirrer. HRh(CO)(TPPTS)
tant, organic solvent, olefin and distilled water were added in
sequence. The autoclave was purged with syn-gas (H :CO = 1:1)
3
, TPPTS, surfac-
2
three times. The reaction was carried out under the desired
pressure and temperature with stirring for a desired time. When
the reaction was completed, the autoclave was cooled to room tem-
perature using cold water and the redundant syn-gas was vented.
The reaction mixture was transferred to a tube, and the upper
organic layer was carefully taken out and analyzed using GC.
After the upper organic phase had been carefully removed, the
catalyst-containing aqueous phase was recharged in the stainless
steel autoclave with fresh olefin and organic solvent. Then, the
steps as described above were carried out. The concentration of
rhodium leaching into the organic phase was determined using
the ICP method.
Table 2. Effect of reaction time on biphasic hydroformylation of NBD
Entry
Reaction
time (h)
Conversion (%)
Selectivity (%)
Results and discussion
Monoaldehydes Dialdehydes
In order to investigate how NBD hydroformylation behaves in
organic/aqueous biphasic and homogeneous systems, preliminary
experiments were conducted using water-soluble HRh(CO)
1
2
3
4
5
6
7
0.5
1.0
9.9
30.6
51.7
81.4
99.1
99.9
99.9
58.3
29.9
12.8
7.1
40.6
67.9
86.0
91.1
95.2
97.0
97.5
2.0
(
(
TPPTS)
3
–TPPTS as biphasic system and oil-soluble HRh(CO)
3.0
TPP) –TPP as homogeneous system, respectively. In both cases,
3
5.0
3.9
the hydroformylation of NBD proceeds smoothly under the same
moderate reaction conditions.
7.0
2.1
10.0
2.0
As evident from Table 1, the hydroformylation products of NBD
are composed of monoaldehydes and dialdehydes. A few hydroge-
nation products of NBD are also present. Surprisingly, the
Reaction conditions are the same as in footnote of Table 1 except the
reaction time.
wileyonlinelibrary.com/journal/aoc
Copyright © 2016 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2016, 30, 335–340

Biphasic hydroformylation of NBD accelerated by cationic surfactants
Table 3. Effect of temperature, pressure and P/Rh molar ratio on
biphasic hydroformylation of NBD
Entry T (°C) P (MPa) P/Rh Conversion
%)
Selectivity (%)
(
Monoaldehydes Dialdehydes
1
2
3
50
70
90
2.0
2.0
2.0
50
50
50
10.1
51.7
95.5
50.5
12.8
4.8
48.5
86.0
94.1
4
2
5
6
70
70
70
70
1.0
2.0
3.0
4.0
50
50
50
50
29.0
51.7
50.9
47.7
30.0
12.8
13.5
15.3
65.9
86.0
85.3
83.2
7
8
9
1
2
1
1
70
70
70
70
70
70
70
2.0
2.0
2.0
2.0
2.0
2.0
2.0
3
10
20
35
50
60
70
6.7
14.5
69.4
75.5
51.7
29.1
25.7
58.2
37.2
7.6
35.1
56.4
89.5
93.4
86.0
70.0
69.0
0
5.7
12.8
28.4
27.9
1
2
Reaction conditions are the same as in footnote of Table 1 except the
corresponding reaction parameters.
into the organic phase and the active catalytic metal species
suffers a huge loss. And the ICP result confirms the leaching
of Rh of 4.13 ppm (6.60%), which is unacceptable from the
point of view of catalyst stability. Hence a moderate temper-
ature of 70°C was employed in the following studies.
Figure 1. Proposed mechanism of NBD hydroformylation catalyzed by HRh
The effect of syn-gas pressure was investigated (Table 3, entries
3
(CO)(TPPTS) .
4–6). The substrate conversion exhibits a large jump from 29.0 to
51.7% when the pressure increases from 1.0 to 2.0 MPa. However,
As shown in Fig. 1, it is suggested that NBD is easily coordinated
further increase in pressure causes a slight decrease in the conver-
sion of NBD. This might be attributed to the excess carbon monox-
ide preventing the forward coordination of NBD with the Rh active
species, thus lowering the reaction rate.
with the Rh complex to form the stable intermediate 2′ which
makes it difficult to transfer to the active species 2 in the homoge-
neous system. In contrast, the low concentration of NBD in water
and the more bulky TPPTS would inhibit the formation of interme-
diate 2′ in the aqueous biphasic system. In this case the formation
of less stereo-hindered species 2 is more favorable, and as a conse-
quence the NBD hydroformylation has higher activity in the aque-
ous biphasic system than in the homogeneous system (Table 1).
As is known, the amount of auxiliary ligand usually affects the reac-
[2]
tion rate and product distribution in biphasic hydroformylation.
Therefore, the effect of the TPPTS/Rh molar ratio was also investi-
gated. The results (Table 3, entries 7–12) suggest that the conversion
of NBD increases quickly with an increase of TPPTS/Rh molar ratio. The
highest conversion and selectivity of dialdehyde (75.5 and 93.4%, re-
spectively) are achieved at a molar ratio of 35. Further increase causes
distinct decreases in both the conversion and the selectivity of
dialdehyde. As the molar ratio of TPPTS/Rh reaches 70, the conversion
is reduced to 25.7% with the selectivity towards dialdehyde decreas-
ing to 69.0 from 93.4% (Table 3, entry 12 versus entry 10).
This might be ascribed to the complex equilibrium of compli-
cated rhodium species present in the biphasic medium, and the
ligand concentration could be appropriately adjusted to produce
the catalytic active species. At a lower ligand concentration, the
Rh active species is hardly generated, thus only marginal aldehydes
are detected at a P/Rh ratio of 3 (Table 3, entry 7). Increasing the
P/Rh ratio possibly shifts the equilibrium towards the direction
where more Rh active species is formed. The highest conversion
at a TPPTS/Rh ratio of 35 is probably attributed to the overwhelm-
ing amount of the catalytic active species. Further increase in TPPTS
would block the coordination sites of the central metal and inhibit
Effect of reaction parameters
The effect of reaction parameters such as temperature, syn-gas
pressure and molar ratio of phosphine to Rh on the
hydroformylation of NBD was investigated in detail to determine
the optimal reaction conditions.
As evident from Table 3 (entries 1–3), reaction tempera-
ture markedly affects the hydroformylation of NBD in the
aqueous biphasic system. The conversion of NBD increases
rapidly with increasing temperature. The conversion is only
1
0.1% when the reaction temperature is 50°C. Products con-
tain monoaldehydes and dialdehydes. When the temperature
increases to 90°C, 95.5% of the substrate is converted to al-
dehydes and the selectivity of dialdehydes is up to 94.1%.
However, the color of the organic phase becomes light yel-
low, which suggests that the aqueous catalyst could leach
Appl. Organometal. Chem. 2016, 30, 335–340
Copyright © 2016 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

X. Yang et al.
the coordination of the NBD substrate with rhodium, which de-
creases the substrate conversion.
an economic and efficient method to improve the reaction rate in
[
19]
biphasic hydroformylation.
Even though harsh reaction condi-
However, also to be taken into account is the chelated coordina-
tion mode of NBD, which would even coordinate with rhodium in
the aqueous phase when they are separated in two immiscible
phases. This might explain the fact that the biphasic
hydroformylation of NBD proceeds well even in the absence of
any additive for improving the solubility of the substrate. In the case
of long-chain terminal olefin biphasic hydroformylation, a TPPTS/Rh
ratio of 30 is enough to immobilize Rh in the aqueous phase and no
leaching of Rh could be detected in the organic phase. Due to
the strong chelated coordination of NBD, a higher molar ratio of
TPPTS to Rh is required to efficiently immobilize Rh species in the
aqueous phase. Therefore, a higher molar ratio of P/Rh = 50 is
employed.
tions could achieve the same ends, we still chose to try a surfactant
in order to conduct the hydroformylation in a moderate reaction
environment for the sake of practical applicability. To determine
the effects of various cationic surfactants in the biphasic hydro-
formylation of NBD, single long-chain cationic surfactants and
double long-chain cationic surfactants were investigated.
As evident from Table 5, compared with the blank experiment
(entry 1), all the single long-chain cationic surfactants employed,
DTAB, CTAB and DTAI, show a marked accelerating effect on the
[
19]
À1
reaction rate at a concentration of 1 mmol l . Additionally no
obvious emulsion is observed after the reaction is completed, and
the phase separation can be easily manipulated. The marked
accelerating effects of the cationic surfactants may be attributed to
[20,27]
the formation of ordered spherical micelles. Our previous work
found that the micelles of the cationic surfactant can attract the
negatively charged catalyst active species to the interface of the
micelles through the electrostatic effect and increase the solubility
of substrate in water by solubilization in the inner core of the
micelles. Hence, the micelles have an advantage in breaking the
mass transportation limitation, thus enhancing the reaction rate.
For a further understanding of the role of the cationic surfactant,
the effects of single long-chain surfactants at various concentra-
tions were investigated (Fig. 2). The results show that all of the con-
versions increase with an increase of the surfactant concentration,
and so does the selectivity of dialdehydes. Also, although most of
the substrate is converted into aldehydes when the concentration
Recycling of catalyst in biphasic hydroformylation of NBD
This part of the study was aimed at investigating the facile
recycling of the costly rhodium complex. The results in Table 4
indicate that the HRh(CO)(TPPTS) –TPPTS system can feasibly
3
be used six times without sharp declines in conversion and se-
lectivity. Since the separation of aqueous catalyst solution from
products was handled in air, which easily caused the oxidation
of TPPTS so losing the coordination ability with Rh, additional
TPPTS is needed to keep the effective concentration of TPPTS
to immobilize the catalyst in the aqueous phase. The results
prove our hypothesis: 0.52 ppm (0.83%) of rhodium leaching
into the organic phase is detected using ICP in the second run
À1
is 8.0 mmol l , the system shows an apparent emulsification which
complicates the decantation, and thus would passively hinder the
separation of the two phases.
(
Table 4, entry 2), but on adding a certain amount of ligand,
the leaching concentration reduces to 0.14 ppm (0.22%), the
conversion visibly increases from 47.7 to 49.4% (Table 4, entries
2
When comparing CTAB and DTAB, the former with a lon-
ger tail does not show a superior accelerating effect until
and 3) and the organic phase is colorless.
The further decrease of conversion might be attributed to the
À1
the concentration reaches 2.0 mmol l , then rapidly gives
À1
the highest conversion of 99.5% at 8.0 mmol l . Unfortu-
unavoidable loss of water and catalyst in the process of recycle
manipulation, since the volume of aqueous phase itself was small.
nately DTAI with the longest tail of 22 carbons does not ex-
hibit the same excellent acceleration as CTAB and DTAB. This
may suggest that a single long-chain surfactant with suitable
hydrophobic tail has a better effect on the reaction rate, that
is, a hydrophobic inner core composed of a shorter tail is fa-
vorable for the sterically demanding substrate NBD. To de-
termine whether the steric hindrance of cationic surfactant
has an impact on the biphasic hydroformylation of NBD,
CPC, which has a pyridyl and an alkyl chain of 16 carbons,
was investigated. The results (Fig. 2) suggest that CPC
Effect of cationic surfactants
Although a considerable yield can be achieved by prolonging
the reaction time (Table 2, entry 7), the turnover frequency of the
catalyst is still unimpressive. The addition of surfactant is admittedly
Table 4. Recycling of catalyst in biphasic hydroformylation of NBD
without any additive
c
Entry Conversion
%)
Selectivity (%)
Organic
b
phase
Rh (%)
Table 5. Effect of single long-chain cationic surfactants on biphasic
(
hydroformylation of NBD
Monoaldehydes Dialdehydes
a
Entry Surfactant
Conversion (%)
Selectivity (%)
1
2
52.2
47.7
11.9
14.1
87.2
84.9
Colorless
Slightly
0.13
0.83
Monoaldehydes Dialdehydes
b
yellowish
Colorless
Colorless
Colorless
Colorless
1
2
3
4
5
—
51.7
79.9
68.7
61.2
52.9
12.8
9.3
86.0
89.9
87.9
81.2
81.7
a
a
a
a
3
4
5
6
49.4
47.8
46.5
45.1
13.2
13.7
14.3
14.9
85.8
85.2
84.8
84.1
0.22
0.19
0.16
0.14
DTAB
CTAB
DTAI
CPC
11.1
17.3
17.1
Reaction conditions are the same as in footnote of Table 1.
Reaction conditions are the same as in footnote of Table 1 except for
the addition of surfactant.
a
Adding half amount of the original ligand (TPPTS).
b
a
À1
Color of upper organic phase.
Surfactant concentration = 1.0 mmol l
In the absence of any surfactant.
.
c
b
Mass fraction of rhodium in the organic phase determined using ICP.
wileyonlinelibrary.com/journal/aoc
Copyright © 2016 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2016, 30, 335–340

Biphasic hydroformylation of NBD accelerated by cationic surfactants
Table 6. Recycling of biphasic hydroformylation of NBD in the presence
of cationic surfactants
Entry Conversion
%)
Selectivity (%)
Emulsification [Rh]
a b
(
of system
(%)
Monoaldehydes Dialdehydes
1
2
3
98.5
91.1
77.9
1.8
10.8
18.3
97.0
88.5
81.4
None
0.19
14.17
24.33
Slight
Serious
a
À4
À1
Reaction conditions: [HRh(CO)(TPPTS)
3
] = 6.1 × 10 mol l in 2 ml of
2
H O, [TPPTS]/[Rh] = 50 (molar ratio), NBD = 0.5 ml (4.9 mmol),
À1
[
CTAB] = 7.0 mmol l , toluene 1.5 mL, 70 °C, 2.0 MPa, 120 min.
b
Mass fraction of rhodium in the organic phase determined using ICP.
microenvironment, which is totally different from a micelle.
The structure, on the one hand, has a tremendously increased
interfacial area and attracts more catalytic active species via its
larger internal and external aqueous phases; on the other
hand, the increased quantity of bilayer alkyl chains form a
more compact hydrophobic region which hardly suits the shift
of NBD to the interfacial area. Thus, the sterically hindered NBD
would with difficultly contact the catalytic active species on
the surface of bilayer membrane and the acceleration is not
clear. The biphasic hydroformylation of dicyclopentadiene
Figure 2. Influence of different kinds of single long-chain surfactants with
various concentrations in the biphasic hydroformylation of NBD.
indeed shows an accelerating effect to some extent, but it is
not as pronounced as that of CTAB. This is in agreement
with our hypothesis that a suitable hydrophobic inner core
microenvironment is beneficial to the reaction.
[
28]
showed the same trend.
Since the single long-chain cationic surfactants show excel-
lent accelerations, the double long-chain surfactants DDMAB,
DCDAB and DCMAB were also employed in the biphasic
hydroformylation of NBD. The results (Fig. 3) indicate that there
is no obvious acceleration until the concentration markedly
Furthermore, we suppose that with an increase in concentration,
the structure of the vesicle might change a lot. High concentration
could possibly cause a sequence of variations in the regular oblate
bilayer membrane and the hydrophobic region would be less
crowded, which makes the movement of NBD easier, thus increas-
ing the conversion.
À1
increases to 8 mmol l . Also, all three give the highest conver-
À1
sions when the concentration reaches 20 mmol l . Comparing
the three double long-chain surfactants, and interestingly,
DCDAB with two tails of 12 and 16 carbons performs better
than DDMAB and DCMAB, which both have two equal-length
tails.
Recycling in presence of surfactants
Finally, catalytic recycling experiments in the presence of
surfactants were conducted. Although an excellent substrate
conversion is achieved (Table 6), the recycle times are less
impressive. Moreover, the system shows emulsification in
the process and ICP analysis detects a loss of Rh metal,
which is detrimental for the separation of the aqueous phase
from the organic phase and the Rh loss is unexpected.
Dilute double long-chain surfactant dissolved in aqueous
[
23]
solution usually forms a vesicle construct.
The vesicle is a
special bilayer membrane structure from the perspective of
Conclusions
3
The hydroformylation of NBD catalyzed by HRh(CO)(TPPTS) –TPPTS
was systematically studied for the first time. Under mild conditions,
the hydroformylation proceeded better in the biphasic system than
in the homogeneous system. The results of the recycling of the cat-
alyst without surfactants showed great stability of the catalyst and
proved its application potential. Cationic surfactants could effec-
tively accelerate the reaction rate of NBD hydroformylation in the
biphasic system. This confirmed the acceleration mechanism of cat-
ionic surfactants that our group previously put forward. However,
the presence of cationic surfactants was detrimental to the reuse
of the catalyst in this system. Determination of the reason requires
further study.
Acknowledgments
This study was supported by the National Natural Science Founda-
tion of China (201202108); the Opening Project Foundation of Key
Figure 3. Influence of different kinds of double long-chain surfactants with
various concentrations in the biphasic hydroformylation of NBD.
Appl. Organometal. Chem. 2016, 30, 335–340
Copyright © 2016 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

X. Yang et al.
[
[
[
15] H. Chemical, Method for producing norbornane dicarboxylic acid ester.
Patent CN 2013, 103459365A.
16] L. Busetto, M. C. Cassani, R. Mazzoni, P. Frediani, E. Rivalta,
J. Organometal. Chem. 2004, 689, 2216.
Laboratory of Sichuan Province (2014LF4001); and the Outstanding
Young Scholars Research Foundation of Sichuan University
(2015SCU04A05).
17] A. Saus, T. N. Phu, M. J. Mirbach, M. F. Mirbach, J. Mol. Catal. A 1983,
1
8, 117.
[18] C. Botteghi, S. Paganelli, A. Perosa, J. Organometal. Chem. 1993,
47, 153.
[19] H. Chen, X. L. Zheng, X. J. Li, Bridging Heterogeneous and Homogeneous
Catalysis: Concepts, Strategies, and Applications, 1st edition, Wiley-VCH,
Weinheim, 2014.
[20] H. Chen, Y. Z. Li, J. R. Chen, Y. E. He, X. J. Li, J. Mol. Catal. A 1999,
149, 1.
[21] M. Li, Y. Z. Li, H. Chen, Y. E. He, X. J. Li, J. Mol. Catal. A 2003, 194, 13.
[22] M. Li, H. Y. Fu, M. Yang, H. J. Zheng, Y. E. He, H. Chen, X. J. Li, J. Mol. Catal.
A 2005, 235, 130.
[23] H. Y. Fu, M. Li, H. Chen, X. J. Li, J. Mol. Catal. A 2006, 259, 156.
[24] H. Y. Fu, M. Li, H. Mao, Q. Lin, M. L. Yuan, X. J. Li, H. Chen, J. Mol. Catal. A
2008, 9, 1539.
[25] H. Chen, H. C. Liu, Y. Z. Li, F. M. Cheng, X. J. Li, J. Mol. Catal. (China) 1994,
8, 124.
[26] K. Hiramatsu, K. Kameyama, R. Ishiguro, M. Mori, H. Hayase, Bull. Chem.
Soc. Jpn. 2003, 76, 1903.
[27] L. B. Wang, H. Chen, Y. E. He, Y. Z. Li, M. Li, X. J. Li, Appl. Catal. A 2003,
242, 85.
References
4
[
[
[
[
1] G. D. Frey, J. Organometal. Chem. 2014, 754, 5.
2] R. Franke, D. Selent, A. Börner, Chem. Rev. 2012, 112, 5675.
3] S. R. Khan, B. M. Bhanage, Catal. Commun. 2014, 46, 109.
4] H. R. Liang, L. Zhang, X. L. Zheng, H. Y. Fu, M. L. Yuan, R. X. Li, H. Chen,
Chin. J. Catal. 2012, 33, 977.
[
[
[
[
5] S. C. Yu, Y. M. Chie, X. M. Zhang, Adv. Synth. Catal. 2009, 351, 537.
6] M. L. Clarke, G. J. Roff, Green Chem. 2007, 9, 792.
7] I. A. Tonks, R. D. Froese, C. R. Landis, ACS Catal. 2013, 3, 2905.
8] E. Boymans, M. Janssen, C. Müller, M. Lutzc, D. Vogt, Dalton Trans. 2013,
42, 137.
[9] C. Y. Zheng, M. Mo, H. R. Liang, X. L. Zheng, H. Y. Fu, M. L. Yuan, R. X. Li,
H. Chen, Appl. Organometal. Chem. 2013, 27, 474.
[
[
10] Y. B. Ma, S. J. Qing, Z. X. Gao, X. Mamat, J. Zhang, H. Y. Li, W. Elia,
T. F. Wang, Catal. Sci. Technol. 2015, 5, 3649.
11] R. Luo, H. R. Liang, X. L. Zheng, H. Y. Fu, M. L. Yuan, R. X. Li, H. Chen, Catal.
Commun. 2014, 50, 29.
[
[
12] T. T. Adint, C. R. Landis, J. Am. Chem. Soc. 2014, 136, 7943.
13] S. H. Chikkali, R. Bellini, B. D. Bruin, J. I. van der Vlugt, J. N. H. Reek, J. Am.
Chem. Soc. 2012, 134, 6607.
[28] X. D. Pi, Y. F. Zhang, L. M. Zhou, M. L. Yuan, R. X. Li, H. Chen, Chin. J. Catal.
2011, 32, 566.
[14] C. L. Joe, T. P. Blaisdell, A. F. Geoghan, K. L. Tan, J. Am. Chem. Soc. 2014,
136, 8556.
wileyonlinelibrary.com/journal/aoc
Copyright © 2016 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2016, 30, 335–340