Integration of a phosphine ligand into an ionic liquid: A highly effective biphasic system for the Rh-catalyzed hydroformylation of 1-octene

Article abstract of DOI:10.1039/c9gc00518h

In classical biphasic ionic liquid (IL) catalysis, the use of a large amount of solvent IL is a major limitation, and usually leads to a waste of resources and relatively low reaction efficiency. So far, it has remained a challenge to establish a highly effective and long-life IL catalytic system that can utilize IL in a relatively efficient, green, and economical manner. Herein, a class of room-temperature phosphine-functionalized polyether guanidinium ionic liquids (RTP-PolyGILs) were synthesized using a simple ion exchange reaction of TPPTS with polyether guanidinium ionic liquids (PolyGILs) based on the notion of integrating phosphine ligand into the IL. These RTP-PolyGILs displayed the characteristics of the phosphine ligand and the solvent IL in both structure and properties, and could thus act not only as ligands to bind metal catalysts but also as catalyst carriers. By exploiting the dual functions of RTP-PolyGILs, we constructed a highly effective, green, and economical biphasic system for the Rh-catalyzed hydroformylation of 1-octene, and examined how the structures of the RTP-PolyGILs affected the activity, selectivity, and stability of the Rh catalysts. It was found that only a catalytic amount of RTP-PolyGILs (about 0.1-0.4 mol% 1-alkenes) was needed to give a high TOF of up to 2300 h^-1, good aldehyde selectivity, long service life with a total turnover number (TTON) of up to 47000, and low Rh leaching of only 0.07-0.3 ppm.

Full text of DOI:10.1039/c9gc00518h

View Article Online
View Journal
Green
Chemistry
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: X. Jin, J. Feng, Q.
Ma, H. Song, Q. Liu, B. Xu, M. Zhang, S. Li and S. Yu, Green Chem., 2019, DOI: 10.1039/C9GC00518H.
Volume 18 Number
7
7
April 2016 Pages 1821–2242
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Green
Chemistry
Cutting-edge research for a greener sustainable future
www.rsc.org/greenchem
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1463-9262
CRITICAL REVIEW
G. Chatel et al.
Heterogeneous catalytic oxidation for lignin valorization into valuable
chemicals: what results? What limitations? What trends?
rsc.li/green-chem

Page 1 of 9
Green Chemistry
View Article Online
DOI: 10.1039/C9GC00518H
RSCPublishing
Green Chemistry
ARTICLE
Integration of A Phosphine Ligand into An Ionic Liquid: A Highly
Effective Biphasic System for The Rh-Catalyzed Hydroformylation
†
of 1-Octene
a
a
a
a
a
a
Xin Jin,* Jianying Feng, Qingqing Ma, Hongbing Song, Qiangqiang Liu, Bingying Xu, Mei
a
b
a
Zhang, Shumei Li and Shitao Yu
In classical biphasic ionic liquid (IL) catalysis, the large use of solvent IL is a major limitation, which usually leads to the
waste of resources and lower reaction efficiency. So far, it remains a challenge to establish highly effective and long-life IL
catalytic system that can utilize IL more efficiently, greenly, and economically. Herein, a class of room temperature
phosphine-functionalized polyether guanidinium ionic liquids (RTP-PolyGILs) were synthesized using a simple ion exchange
reaction of TPPTS with polyether guanidinium ionic liquids (PolyGILs) based on the notion of integrating phosphine ligand
into IL. These RTP-PolyGILs possessed the characteristics of the phosphine ligand and the solvent IL in both structure and
properties, and could thus act not only as ligands to bind metal catalysts but also as catalyst carriers. By exploiting the dual
functions of RTP-PolyGILs, we constructed a highly effective, green, and economical biphasic system for the Rh-catalyzed
hydroformylation of 1-octene, and examined how the structures of the RTP-PolyGILs affected the activity, selectivity, and
stability of the Rh catalysts. It was found that only a catalytic amount of RTP-PolyGILs (about 0.1–0.4 mol% 1-alkenes) gave
Received 00th February 2019,
Accepted 00th February 2019
DOI: 10.1039/x0xx00000x
−1
high TOF up to 2300 h , good aldehydes selectivity, long service life with a total turnover number (TTON) up to 47000, and
low Rh leaching of only 0.07–0.3 ppm.
www.rsc.org/greenchem
2
2
3
3
4
0
5
0
5
0
diffusion resistance and usually causes the reaction to occur at the
IL/substrate interface, which can decrease the catalytic efficiency
because a large part of the active catalysts cannot take part in the
Introduction
The separation, recovery and recycling of expensive homogeneous-
6
reaction . Furthermore, excessive impurities in the solvent IL may
1
catalyst have been an enormous challenge in homogeneous
7
decrease the stability of catalysts by oxidation, decomposition, etc .
catalysis and have attracted increasing attention in the past
decades. Many promising strategies have been put forward to
conquer this problem , among which the biphasic ionic liquid (IL)
catalysis has been considered to be one of the most competitive
methods because of the attractive natures of IL, such as low vapor
pressure, non-flammability, good stability, strong conductivity, and
excellent solubility towards transition metal catalysts . In particular,
the IL can be assigned the specific functionality required for
particular needs and then designed accordingly because its
Up to now, it remains a challenge to utilize IL more efficiently,
greenly and economically, and highly effective and long-term stable
biphasic IL catalytic systems are urgently needed.
5
0
5
2
8
Supported ionic liquid catalysis provides a new idea to solve this
problem by combining the advantages of both the solvent IL and
the support material, which significantly reduces the use of solvent
IL and improves the mass transport. However, since the functions of
3
1
4
the IL can be customized for particular needs , we are interested in
finding out if the problem can be overcome simply by
functionalizing the IL itself. In our view, the crux to solving the
problem is creating functionalized ionic liquid (FIL) that can
effectively integrate the solvent IL and phosphine ligand (or
catalyst) based on the intrinsic designability of IL, so that the
resulting FIL can inherit not only the ability of the ligand to complex
with transition metal but also the solvent properties of the solvent
IL as the carrier of the catalyst. In this way, in a biphasic IL system, a
catalytic amount of FIL may play the dual role of the phosphine
ligand and solvent IL at the same time to cut the use of the solvent
IL down to a level that qualifies as efficient, green, and economical
4
structure can be readily modified .
However, the main trouble of biphasic IL catalysis is that a large
number of solvent IL is used to dissolve and support the
homogeneous-catalyst, which breaches the principles of green
1
5
chemistry and causes unbearable consumption, and may even
aggravate certain problems in catalytic reactions. For example, the
heavy use of highly viscous solvent IL increases the substrate
a. State Key Laboratory Base for Eco-Chemical Engineering in College of Chemical
Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Street,
Qingdao 266042, China. E-mail: jinx1971@163.com (X. Jin).
utilization.
b.
9
College of Physical Education, Qingdao University of Science and Technology, 53
45 Some studies attempted to attach phosphine ligands onto ionic
groups that resemble the cations of the solvent IL, such as
imidazolium, guanidinium, phosphonium, pyridinium, and other
Zhengzhou Street, Qingdao 266042, China.
†
Electronic Supplementary Information (ESI) available: See
DOI: 10.1039/x0xx00000x

Green Chemistry
Page 2 of 9
ARTICLE
Green Chemistry
various onium ions. Phosphine ligands were thus integrated by
View Article Online
DOI: 10.1039/C9GC00518H
1
0
11
covalent or electrovalent bonding to afford a number of
phosphine-functionalized ionic liquids (P-FILs). However, these
efforts aimed at none but enhancing the solubility and affinity of
phosphine ligands in and towards the solvent ILs to reduce the
leaching of noble metal. These P-FILs indeed improved metal
leaching to some extent, but they generally have high melting point
5
0
5
0
5
0
5
0
5
0
5
m
(T ) and were not at all a solvent IL at room temperature. As a
result, it was still necessary to add a large amount of solvent IL in
catalytic reaction, which often amounted to 30–6500 times
1
1
2
2
3
3
4
4
5
5
(
mol/mol) the amount of the noble metal (equivalent to 30–350
1
0,11
mol% of substrate)
to dissolve these high melting point P-FILs.
The reaction was hence still not efficient, green, or economical in
terms of IL use. The removal of solvent IL and use of just a catalytic
amount of P-FIL was only attempted in a study on the continuous
1
2
flow hydroformylation in supercritical carbon dioxide , in which a
stable-state mixture of aldehyde and olefin was used as the
reaction medium that dissolved both the Rh precursor and the P-FIL.
However, the olefin flow rate had to be regulated cautiously to
maintain a steady state and prevent the catalyst from precipitating.
In other words, the P-FILs in existing literature integrated phosphine
ligands with ILs only structurally, rather than functionally. However,
we believe that the integration of phosphine ligands and solvent IL
m
should be further improved to reduce the T of P-FILs and making
them practically “functional”, that is, to serve both as the ligand and
as the solvent.
In recent years, polyether ionic liquids are increasingly applied in
catalysis13 since the T
and viscosity of these ILs are significantly
m
reduced after polyether chains are introduced into the cationic
structures of classical ILs. Recently, we also synthesized a polyether
guanidinium ionic liquid (PolyGIL, 1b in Scheme 1), which exhibited
Scheme 1 Integration of phosphine ligand into ionic liquid, our previous and
6
0
current means in recycling of homogeneous-catalyst.
1
4
room temperature T
m
and was used as the solvent and the carrier
of Rh-TPPTS in the biphasic hydroformylation of olefins (Scheme 1).
-1
selectivity, and stability of the Rh catalysts were investigated. With
this work, we aim to achieve greener, more efficient, and more
economical utilization of ILs to establish an IL catalytic system that
possesses high activity, good selectivity, as well as easy separation,
recovery, and recycling of catalyst, whilst maintaining a long service
life of the catalyst.
Regrettably, the TOF of this biphasic IL system was less than 200 h
because the heavy use of PolyGIL (equivalent to 28 mol% of the 1-
alkene) as the solvent IL limited the mass transfer.
Enlightened by the distinctive properties of polyether ILs, we
figured that assembling PolyGIL and the phosphine-sulfonate ligand
6
5
(e.g., TPPTS) via ion exchange should afford a novel room
temperature phosphine-functionalized polyether guanidinium ionic
liquid. Incorporating the polyether guanidinium cations into the
phosphine-sulfonate anion would give the features of PolyGIL to the
Results and discussion
Based on the design ideas (i.e., to integrate phosphine ligands into
resulting new sulfonated phosphine ligand, e.g., a decreased T
m
,
liquefaction at room temperature, readily adjustable solubility. 70solvent IL), we first synthesized four RTP-PolyGILs (Scheme 1, 2a-d)
Such multi-functional integrated ILs combining both the phosphine by the ion exchange between TPPTS with four PolyGILs (Scheme 1,
ligand and the IL would make it possible to construct highly 1a-d) carrying different capping groups (e.g., methoxyl or phenoxyl)
effective and long-term stable catalytic systems.
In this paper, a series of room temperature phosphine- TPPTS was selected as a model ligand because it was widely used in
functionalized polyether guanidinium ionic liquids (RTP-PolyGILs, 2 75biphasic catalysis, especially in the hydroformylation of alkenes in
in Scheme 1) were designed and synthesized by the ion exchange ILs . These ion exchange reactions had high yields (86%–95%), and
reaction of TPPTS with PolyGILs (Scheme 1, 1). With these materials, H NMR spectroscopy proved that the residual CH SO Na in the
which existed as liquids at room temperature, we demonstrated the product was less than 5%.
and/or different number of ethylene oxide (EO) units (n = 4 or 16).
1
5
1
3
3
successful Rh-catalyzed hydroformylation of higher olefins in a
highly effective and long-life biphasic catalytic systems that 80scanning calorimetry (DSC). As expected, replacing Na with the
eliminated solvent ILs but used only a catalytic amount of RTP- polyether guanidinium cations successfully turned the dystectic
Next, we examined the Tm of the RTP-PolyGILs by differential
+
PolyGILs (equivalent to 0.1–0.4 mol% of 1-alkenes) (Scheme 1). The TPPTS into room temperature ILs having a T between 10 and 20 °C
m
effects of the structure of the RTP-PolyGILs on the catalytic activity,
(Tm 2b = 19.3 °C; Tm 2d = 10.6 °C), or not observable (for 2a and 2c),
2
| Green Chemistry, 2019, 00, 1-3
This journal is © The Royal Society of Chemistry 2019

Page 3 of 9
Green Chemistry
Green Chemistry
ARTICLE
which revealed the successful integration of phosphine ligands and example, 2a and 2c, both having 4 EO units, wereVieiwnsAortilculebOlenlinine
solvent ILs in both their structure and nature, allowing the removal toluene, but 2b and 2d, both having 16DOEOI: 1u0.n10it3s9,/Cw9eGrCe0e0a51s8ilHy
of solvent IL and using the RTP-PolyGILs alone as both the ligand soluble in toluene. Hence, the RTP-PolyGILs possessed rising
1
7
and the carrier of matal catalyst in the catalytic reaction. Attempts 40lipophilicity with the elongation of their polyether chain .
1
0,11
5
0
5
0
5
0
to do so by ionizing neutral ligands have been unsuccessful
.
Considering the characteristics of the RTP-PolyGILs in terms of
and miscibility, we believed that they could be used only in
chain , the lattice energy of TPPTS was significantly reduced, which a catalytic amount to establish a liquid/liquid biphasic system for
then afforded a T of room temperature or even lower. the hydroformylation reaction and realize the facile separation,
Thanks to the high flexibility and rotational freedom of the ether both T
m
1
6
m
In our study, Rh-catalyzed hydroformylation of 1-octene, a typical 45recovery, and recycling of Rh catalyst. With this in mind, we set out
homogeneous catalytic reaction, was selected as the model to construct the biphasic system of Rh-RTP-PolyGILs/1-octene and
reaction, so we examined the miscibility of the RTP-PolyGILs with evaluate the capability of Rh-2 without any solvent IL (Table 1).
the 1-octene substrate and the n-nonanal product at room Firstly, the Rh-2 catalyst was preformed by mixing Rh(acac)(CO)
temperature (25 °C) and 100 °C (reaction temperature of and 2 at a molar ratio of 1:10 for 1 h at 100°C and under 5.0 MPa
hydroformylation), because the miscibility directly determined the 50syngas. Freshly preformed Rh-2d catalyst was submitted to P NMR
state of the reaction system before, during, and after the reaction analysis (Figure S21), and a double peak (J = 128 Hz) was observed
3
i.e., homogeneous or biphasic). As expected (Figure 1), the RTP- at the δ 32.1, indicating the formation of HRh(CO)(2d) as the
PolyGILs were completely immiscible with 1-octene both at room precursor of the catalytic active species11c. At this point, 1-octene
temperature and 100 °C, showing that a biphasic catalytic system was added to the reaction system. Although only a catalytic amount
could be formed between 1-octene and the RTP-PolyGILs. However, 55of 2 was present (equivalent to 0.1 mol% 1-octene), a liquid/liquid
their miscibility with n-nonanal could not be readily predicted. For biphasic system could be clearly observed at both room
example, 2a was immiscible with n-nonanal at both room temperature and 100 °C under atmospheric pressure. The
temperature and 100 °C, but 2b was miscible with n-nonanal at hydroformylation then proceeded at 100 °C and under 5.0 MPa
both room temperature and 100 °C, possibly because the syngas pressure. In order to determine the initial catalyst activity,
hydrophile-lipophile balance value of 2b and n-nonanal was similar. 60the hydroformylation was terminated after 30 min by placing the
Interestingly, 2c and 2d were immiscible with n-nonanal at room autoclave in an ice bath, at which time the conversion of 1-octene
temperature but easily miscible at 100°C, indicating that they had a was approximately 4%–13% (entries 1–4 in Table 1) and the mixture
temperature-dependent solubility. Obviously, the immiscibility of remained in a biphasic state. Since we wanted to know more about
RTP-PolyGILs with aldehydes would be very helpful to separating the state of the system at the reaction temperature (100 °C), the
them efficiently from aldehydes in hydroformylation. In addition, it 65two-phase system was raised to 100 °C again, and the two-phase
was found that the RTP-PolyGILs were easily soluble in polar state did not change. Hence, the system had been in a two-phase
solvents (e.g., methanol and ethanol) but insoluble in non-polar state throughout the initial 30 minutes of the reaction. This did not
solvents (e.g., n-heptane). Note that the solubility of the RTP- contradict the observation that most RTP-PolyGILs (2b, 2c, and 2d)
1
1
2
2
3
2
3
1
(
PolyGILs in toluene relied on the length of the ether chain. For
were miscible with n-nonanal at 100 °C because the upper layer
mostly contained unconverted 1-octene and aldehydes only
amounted to 3%–12% (data based on the conversion rates and Sald
of entries 1–4 in Table 1). It could be expected that the reaction
rate was mainly controlled by the mass transfer when the olefin
conversion was low.
70
75
80
85
90
Table 1 shows that Rh-2 had high catalytic activity and 2d
−1
gave the best activity with a TOF value greater than 2300 h
entry 4 in Table 1). This result revealed that the nature of the
(
polyether guanidinium cation was vital for achieving high rate.
For the RTP-PolyGILs with the same capping group on the
polyether chain, the TOF value increased significantly as the
chain length increased. For example, 2b (entry 2, Table 1) and
2
d (entry 4, Table 1), both carrying 16 EO units, gave TOF
values that were 2.4 and 2.5 times that of 2a (entry 1, Table 1)
and 2c (entry 3, Table 1), both carrying 4 EO units,
respectively. It is well known in biphasic catalysis that the mass
transport control generally predominates over kinetic control,
and it was reported that ILs modified with longer ether chains
1
8
had lower viscosity . Thus, the observed rate increase could
be partly attributed to the longer ether chains of 2b or 2d that
2
made it easier for H and CO to transfer into the catalysts. A
3
5
1
7
previous study prompted us to find out if the enhanced
activity also (or even mainly) came from the higher solubility of
Fig. 1 Miscibility of RTP-PolyGILs with 1-octene and n-nonanal.
This journal is © The Royal Society of Chemistry 2019
Green Chemistry, 2019, 00, 1-3 | 3

Green Chemistry
Page 4 of 9
ARTICLE
Green Chemistry
View Article Online
Table 1 Hydroformylation of 1-octene in the Rh-RTP-PolyGILs/1-octene biphasic systems a
DOI: 10.1039/C9GC00518H
CHO
Rh-2, CO/H2
5
CHO
+
5
5
TMG]+
Conv. b (%)
S
ald (%)
c
n/i d
TOF e (h−1)
Entry
RTP-PolyGIL
or Ligand
Solvent IL
Cation/[R(EO)
n
R
N
1
2a
None
None
None
None
1d
Me
Me
Ph
Ph
Ph
Ph
Ph
4
4.3
8.0
6.4
12.6
8.5
9.9
7.9
65.0
83.3
72.6
91.9
89.5
63.1
70.0
2.2
2.6
3.1
2.6
2.6
2.8
1.9
559
1332
934
2309
1525
208
55
2
2b
16
4
3
2c
4
2d
16
16
16
16
5 f
6 g
7 h
2d
TPPTS
2d
1d
None
a
2 2
Reaction conditions: p (1:1 H /CO) = 5.0 MPa, T = 100 °C, t = 0.5 h, Rh(acac)(CO)
1.0 mg, 2/Rh = 10, 1-octene/Rh = 10,000, rate of stirring = 400 rpm. b Conversion
of 1-octene was determined by GC with the n-hexane as an internal standard. c The combined selectivity to normal aldehyde and 2-methyl aldehyde. d Ratio of
normal aldehyde to 2-methyl aldehyde. Turnover frequency (TOF): mol (aldehyde) per mol (rhodium) per hour. 0.5 g 1d. TPPTS/Rh = 10, t = 3 h, 0.5 g 1d. h Trans-
e
f
g
2
-octene as substrate, T = 120 °C, t = 2 h, trans-2-octene/Rh = 2000.
1
-octene in the more lipophilic 2b or 2d, since this could be an suggested that rhodium was almost entirely retained in the
explanation when the solubility of the RTP-PolyGILs in toluene RTP-PolyGILs phase.
was taken into account. Thus, the effects of the capping
It is commonly known that in biphasic reaction using solvent
5
0
5
0
5
0
5
groups on the mass transfer of the olefin were examined. ILs and transition metal catalyst, the solvent ILs are responsible
Indeed, ILs whose polyether chain terminated with a phenoxy 40for dissolving and loading metal catalysts and are thus used in
group (2c and 2d) gave higher TOF than corresponding those a large amount. In contrast, in our two phase system, only a
with a methoxy group (2a and 2b), probably because the catalytic amount of RTP-PolyGILs sufficed both as the ligand
stronger lipophilicity of the phenoxy group than the methoxy and as the support for the Rh-catalyst by coordinating with Rh.
group17 improved the mass transport of 1-octene into the 2c To compare our system with conventional biphasic IL system,
or 2d phase. It was also reported that the solubility of alkenes 45we surveyed the effect of extra solvent IL on the catalytic
in alkyl-substituted imidazolium-based ILs increased with the performance of Rh-RTP-PolyGILs. Table 1 shows that additional
1
1
2
2
3
3
1
0b,10g,19
−1
chain length of the alkyl substituent
catalyzed hydroformyl-ation of 1-octene, the chemoselectivity
(Sald) for aldehydes as the main products (mainly 1-nonanal realized that the mass transport limitation from the liquid
and 2-methyl octanal) appeared acceptable, with 2d affording 50(alkene) or gas (H /CO) phase into the PolyGIL phase (solvent)
. In the Rh-2- PolyGIL 1d dropped the TOF markedly from 2309 h to 1525
−1
h
(entry 4 vs. entry 5) with Rh-2d as the catalyst. We soon
2
the highest Sald of nearly 92% (entry 4, Table 1) along with its should be blamed for this impaired activity. That is, in the
best catalytic activity. Isomeric olefins were the main by- biphasic system of Rh-2d/1d/1-octene (entry 5, Table 1), the
products, and no hydrogenation products were found. Note slower diffusion of olefin and gases due to the presence of the
that the chemoselectivity for aldehydes to some extent solvent IL 1d restricted the reaction to occur at the olefin/1d
depended on the length of ether chain, since Sald was higher 55interface, and a large amount of catalytically active species in
and olefin isomerization was less for 2b (entry 2, Table 1) and the bulk phase of 1d could not participate, which impaired the
2
d (entry 4, Table 1) than for 2a (entry 1, Table 1) and 2c reaction rate. In contrast, the concentration of catalytically
(entry 3, Table 1), respectively. We attributed this result to the active species at the 2d/olefin interface and in the bulk phase
better mass transfer of CO due to the lower viscosity thanks to of 2d increased greatly without 1d (entry 4, Table 1), which
the longer ether chain, because it was reported that 60significantly improved the catalytic efficiency.
isomerisation was less when the partial pressure of CO was
The performance of our catalytic system was assessed using
higher1
0h,12a
. As for regioselectivity, a moderate selectivity for the conventional Rh-TPPTS/1d/1-octene biphasic system as
the normal aldehyde was observed (n/i = 2.2–3.1), which was the benchmark. As expected, the Rh-TPPTS catalyst gave a
−1
typical for monophosphine rhodium catalyst and indicated much lower activity (TOF = 208 h ) in the solvent IL 1d than
that Rh-2 catalysts were formed in the RTP-PolyGILs phase. To 65Rh-2d in 1d (entry 6 vs. entry 5, in Table 1), since TPPTS was
further verify whether rhodium was effectively immobilized in less soluble in 1d, whereas 2d was easily soluble in 1d because
the RTP-PolyGILs phase, we checked the rhodium content in 2d and 1d were similar in polarity as a result of having a same
the product phase using ICP-AES and found that the rhodium polyether guanidinium moiety. This was in agreement with the
leaching into the organic phase was less than 0.02 ppm, which performance of Rh-TPPTS in the biphasic hydroformylation of
4
| Green Chemistry, 2019, 00, 1-3
This journal is © The Royal Society of Chemistry 2019

Page 5 of 9
Green Chemistry
Green Chemistry
ARTICLE
temperature rose to room temperature and a liquid/liquid two
View Article Online
DOI: 10.1039/C9GC00518H
phase system appeared again. Interestingly, when the temperature
4
4
5
5
6
0
5
0
5
0
continued to rise to 100°C, the whole system became one phase (C,
Figure 2), which indicated the temperature-controlled solubility of
2
d. These observations agreed with preceding results on the
melting point of 2d and its solubility in n-nonanal, and revealed that
there was a reaction-controlled transition from B (two phases) to C
(one phase) as the generated aldehydes gradually increased in the
reaction. Accordingly, we speculated that the rising proportion of
nonanal in the organic phase led to an increasing solubility of 2d in
the organic phase, and the reaction site gradually shifted from the
initial IL phase to the organic phase. As a result, the mass transport-
controlled biphasic reaction in the initial stage gradually turned into
a kinetically controlled homogeneous reaction. Hence, the reaction-
controlled homogenization (B to C) improved the reaction
efficiency, while the temperature-controlled phase separation (C to
D) allowed the efficient recycling of Rh catalyst.
Figure 3 shows that Rh-2d had a long service life in our biphasic
system with a total turnover number (TTON) up to 47000. Within
eleven consecutive runs, the conversion of 1-octene stayed at >90%
with good chemoselectivity for aldehydes (Sald) and nearly an
invariable selectivity for the normal aldehyde (Sn-ald) of 68%–72%,
corresponding to n/i = 2.2–2.5. Only in the last two cycles, the
aldehyde selectivity dropped moderately along with an increase of
isomerized olefins. The Rh loss was 0.07–0.3 ppm (0.05%–0.2% of
the Rh loaded) for each of the first 9 runs, but then increased to 2–6
Fig. 2 The starting and ending states of the reaction system at 5°C and
1
1
00°C, A: starting state at 5°C, liquid/solid two phase; B: starting state at
00°C, liquid/liquid two phase; C: ending state at 100°C, one phase; D:
5
ending state at 5°C, liquid/solid two phase.
olefin based on imidazolium ILs10c,15. The good performance of Rh- ppm (1.5%–4.0% of the Rh loaded) in the last two runs. The
2
d for 1-octene prompted us to test substituted alkenes such as 65increase of isomerized olefin in the last two cycles was apparently
-1
trans-2-octene (entry 7, Table 1). Lower TOF (55h
)
and related to the sudden increase in rhodium loss, which was
] species, known as a good
This was within expectation catalyst for olefin isomerization and easily dissolved in the organic
10
15
20
25
30
35
moderate n/i (1.9) value was obtained despite using a higher attributed to the formation of [HRh(CO)
reaction temperature (120 °C)
because it is well known that diphosphine ligands with a large phase . The oxidation of the phosphine ligands should be
bite angle are generally more suited for the isomerization- 70responsible for the formation of [HRh(CO) ] because the catalyst
hydroformylation of internal alkenes , while 2d is a typical separation operation was carried out in air and had already gone
monophosphine ligand. through nine cycles. To verify this hypothesis, the reused Rh-2d
To survey the service life of the Rh-RTP-PolyGILs catalysts in our catalyst after the eleventh cycle (from a parallel cyclic test) was
biphasic hydroformylation system, we used the Rh-2d/1-octene analyzed using P NMR (Figure S22), which showed that 2d was
system as a model and focused on the separation, recovery, and 75completely oxidized (Figure S22 vs. Figure S21). We supplemented
recycling of the Rh catalyst. Knowing that this system maintained
4
.
2
1
4
2
0
3
1
two phases at the initial hydroformylation stage owing to the low
olefin conversion, we were interested in the system state during
the reaction and after the conversion of most 1-octene to aldehyde.
In the first run, we examined the phase behavior and miscibility of
the reaction system. Figure 2 illustrates the starting and ending
states of the reaction system at 5 °C and 100 °C. It can be clearly
observed that a two phase system (liquid/solid, L/S or liquid/liquid,
L/L) was formed after the addition of 1-octene into the preformed
Rh-2d at the starting point of the reaction, whether at 5°C (A, L/S,
Figure 2) or 100 °C (B, L/L, Figure 2). After the reaction had
proceeded for 5 h and was terminated by cooling in the ice water,
we found that the system presented a liquid/solid two phase state
(D, L/S, Figure 2), at which time Rh-2d solidified to form a lower
layer and the organic phase in the upper layer contained about 95% Fig. 3 Catalyst recycling in the Rh-2d/1-octene biphasic hydroformylation system,
aldehyde. Thus, the most convenient separation of the catalyst Sn-ald = normal aldehyde/(normal aldehyde + 2-methyl aldehyde), reaction
from aldehydes was to decant, even more simply finished rapidly in 80conditions: Rh(acac)(CO) = 1.0 mg, 2d/Rh = 20, 1-octene/Rh = 5,000, p(1:1 H /CO)
2
2
air, without the trouble of using an inert atmosphere. After the ice = 5.0 MPa, T = 100 °C, t = 5 h, in the twelfth run, one tenth of the originally
bath was removed, the solidified lower layer melted when the loaded 2d was supplemented.
This journal is © The Royal Society of Chemistry 2019
Green Chemistry, 2019, 00, 1-3 | 5

Green Chemistry
Page 6 of 9
ARTICLE
Green Chemistry
View Article Online
Table 2. Comparison of our biphasic system with some classic biphasic systems for Rh-catalyzed hydroformylation of 1-alkenes
DOI: 10.1039/C9GC00518H
Entry
System
Solvent IL or
Solvent IL/
1-alkene
Ligand
TOF
n/i
TTON
Rh Leaching
(ppm)
Ref
−1
reaction medium
(h )
(mol %)
1 a
2 b
3 c
Biphasic
[BMIM][BF
]
44.6 e
—
[BDMIM]
[P(C
H
SO
SO
SO
)
]
1380 e
517
2.2
3.0
3.2
31248 e
—
0.3–4.1
<0.1
11c
7b
4
3
6
4
3
3
scCO
scCO
2
-Biphasic
-Biphasic
[OctMIM][NTf
2
]
[PMIM][Ph
2
P(C
6
H
4
3
)]
2
a stable state mixture
of olefin and aldehyde
None
—
[OctMIM][Ph
2
P(C
6
H
4
3
)]
239
—
5–10
12a
4 d
Our system
—
2d
2309
2.6
47138
0.07–0.3
—
a
as Rh precursor, ligand/Rh = 10, 1-hexene as substrate. b Supercritical CO
as Rh precursor, 1-octene as substrate. c Supercritical CO
/H /CO) = 14 MPa, T = 100 °C, Rh(acac)(CO) as Rh precursor, ligand/Rh =
Biphasic IL system: p (1:1 H
2
/CO) = 4.0 MPa, T = 100 °C, Rh(acac)(CO)
/H /CO) = 20 MPa, T = 100 °C, Rh(acac)(CO)
continuous flow): Rh catalyst dissolved in substrate–product mixture, total pressure (CO
5, 1-octene as substrate. d p (1:1 H as Rh precursor, 2d/Rh = 10, 1-octene as substrate. e Calculated based on data from
/CO) = 5.0 MPa, T = 100 °C, Rh(acac)(CO)
ref.
2
2
-IL biphasic system
(continuous flow): total pressure (CO
2
2
2
2
biphasic system
(
2
2
2
1
2
2
one tenth of the originally loaded 2d to the reaction in the green application of ILs in only a catalytic amount.
twelfth cycle and found that the selectivity was A patent related to our research was filed as early as 2013
2
2
almost restored to the initial level, which further validated that and authorized in 2016 .
the oxidation of 2d decreased the selectivity and increased the
5
0
5
0
5
0
5
0
rhodium loss. Similar phenomenon has also been reported by
Lin et al1
9c
Conclusions
.
We believe that the long service life of our system benefited
from the unique properties of RTP-PolyGILs, which stemmed
from the structural design that integrated the ligand and the
solvent IL. The reaction-controlled phase transition (from two
phases to one phase) effectively improved the reaction rate,
while the temperature-controlled phase transition (from one
phase back to two phases) successfully inhibited Rh leaching
into the organic phase. Even though the separation of Rh-2d
was carried out in air, the negative effects (decreased the
selectivity and increased the Rh leaching) due to the oxidation
of ligands became significant only after the ninth run. Thus,
the solidification of 2d effectively thwarted the diffusion of air
into the IL phase and minimized ligand oxidation. In addition,
we speculated that the Rh catalytic active species might have
been stabilized by the electrostatic shielding and steric
hindrance of the surrounding polyether guanidine cations,
which prevented the formation of inactive Rh clusters.
4
5
5
6
5
0
5
0
In conclusion, we have prepared a class of room temperature
phosphine-functionalized polyether guanidinium ionic liquids
1
1
2
2
3
3
4
(RTP-PolyGILs) that possessed the characteristics of room
temperature ILs. We believe that the RTP-PolyGILs provide an
efficient platform for the task-specific design of ILs, i.e., "build
for purpose". Therefore, the real potential of RTP-PolyGILs lies
in their universality for catalytic reactions, since the sulfonated
ligands as the anions of RTP-PolyGILs could be adjusted based
on the target catalytic reaction. The catalyst performance,
including the activity, chemoselectivity, regioselectivity, and
stereoselectivity, could all be readily managed by changing the
type and structure of the sulfonated ligands. According to the
application requirements, the physicochemical properties of
RTP-PolyGILs, including phase transition, polarity, solubility,
viscosity, etc., could also be tuned easily by changing the
substituents or/and number of ethylene oxide units of the
onium cation.
Table 2 compares our system with some classic biphasic
systems (biphasic IL system, as well as continuous flow
biphasic system using supercritical CO ). Note that all these
2
systems used P-FILs (entries 1–3, Table 2). Compared with RTP-
PolyGILs, their catalysts lacked the polyether chain moiety and
We are confident that RTP-PolyGILs can be further extended
to other catalytic reactions. More detailed and systematic works
are already underway.
did not demonstrate the nature of a solvent IL at room 65Experimental
temperature. Therefore, the use of a large amount of reaction
media was necessary, either a solvent IL (entries 1 and 2, Table
Materials and methods
2
) or the mixture of the olefin and the aldehyde (entry 3, Table Crude materials including 1-octene, Rh(acac)(CO)
2
, and TPPTS
2
). Consequently, this directly reduced the reaction efficiency were obtained from Acros or J&K. The PolyGILs were prepared
1
4
(TOF and TTON) and led to waste of resources (entries 1–3 vs. according to our previously published method . All
, Table 2). In contrast, our system was far superior in all 70experimental operations were carried out strictly according to
4
respects, e.g., the amount of ILs used, catalytic activity (TOF), standard Schlenk techniques under Ar atmosphere. All
catalyst service life (TTON), and Rh loss. Integrating the solvents and reagents were purified and deoxygenated
phosphine ligand and IL both in structure and property into according to standard procedures . A 60 mL stainless steel
RTP-PolyGILs certainly allowed the efficient, economical, and autoclave was used for the hydroformylation reaction. The
2
3
6
| Green Chemistry, 2019, 00, 1-3
This journal is © The Royal Society of Chemistry 2019

Page 7 of 9
Green Chemistry
Green Chemistry
ARTICLE
conversion and selectivity were analyzed by GC on an OV-101
capillary column with a FID detector. The products of the
hydroformylation were identified by GC-MS on a DB-35MS
capillary column using an Agilent 6890/5973 GC-MS apparatus.
Melting point was determined by DSC on a Mettler Toledo
Conflicts of interest
There are no conflicts of interest to declare.
View Article Online
DOI: 10.1039/C9GC00518H
5
0
5
0
5
0
5
0
5
0
5
6
0
Acknowledgements
2
DSC1 instrument with N atmosphere. A Bruker AVANCE 500
We gratefully acknowledge the financial support from the
National Natural Science Foundation of China (No.21576144),
the Natural Science Foundation of Shandong Province (No.
ZR2014BM009) and Taishan Scholars Projects of Shandong
(No. ts201511033).
and an AVANCE III 600 spectrometer were used to record the
1
13
31
H NMR, C NMR, and P NMR (85% phosphoric acid as the
internal standard) spectra. High resolution mass spectrometry
was recorded using a Q-ToF Ultima Global mass spectrometer.
Rh leaching was measured by ICP-AES analysis on an IRIS
Intrepid II XSP apparatus.
1
1
2
2
3
3
4
4
5
5
6
5
3 6 4 3 3 2
Synthesis of [Ph(EO)16TMG] [P(C H SO ) ] (2d). TPPTS·4H O (1.5
Notes and references
g, 2.3 mmol), 1d [Ph(EO)16TMG][OMs] (6.6 g, 6.7 mmol) and
acetonitrile (25 mL) were mixed in a 100 mL Schlenk flask under Ar
atmosphere. The mixture was stirred at room temperature for 72 h
1
(a) B. Cornils and W. A. Herrmann, Applied Homogeneous
Catalysis with Organometallic Compounds, 1st edn, Wiley-
VCH, Weinheim, Germany, 1996; (b) W. D. Jones, in
Comprehensive Organometallic Chemistry III, Vol. 1, Ed. G.
Parkin, Elsevier Science, Amsterdam, 2007, p. 699–723; (c) J.
E. Perea-Buceta, I. Fernández, S. Heikkinen, K. Axenov, A. W.
T. King, T. Niemi, M. Nieger, M. Leskelä and T. Repo, Angew.
Chem. Int. Ed. 2015, 54, 14321; (d) D. Margetic, in
Superbases for Organic Synthesis, Ed. T. Ishikawa, Wiley,
Hoboken, 2009, p. 9–48.
1
and terminated when H NMR analysis showed that less than 5%
3 3
residual CH SO
Na remained in the products. The mixture was 70
filtered and acetonitrile was removed under reduced pressure to
give 2d, which was a yellow viscous liquid at 25°C and solidified at
1
<
10 °C. Yield: 6.7 g (95%). H NMR (500.0 MHz, D
2
O): δ = 7.87 (d,
3
H, P-Ph-H), 7.82 (d, 3H, P-Ph-H), 7.59 (t, 3H, P-Ph-H), 7.51 (t, 3H, P-
Ph-H), 7.41 (t, 6H, O-Ph-H), 7.10–7.05 (m, 9H, O-Ph-H), 4.24–3.39 75
1
3
(
m, 200H, OCH
CDCl ): δ = 162.53, 158.59, 146.81, 136.52, 134.43, 130.10, 129.24,
28.36, 126.77, 120.66, 114.44, 70.34, 69.58, 67.13, 44.61, 39.74;
2 2 3 2
CH ), 2.96 (s, 36H, 6×N(CH ) ); C NMR (150.9 MHz,
2
For reviews, see: (a) B. Cornils, W. A. Herrmann, I. T.
Horváth, W. Leitner, S. Mecking, H. Olivier-Bourbigou and D.
Vogt, Multiphase Homogeneous Catalysis, Wiley–VCH,
Weinheim, Germany, 2005; (b) D. J. Cole-Hamilton and R. P.
Tooze, Catalyst Separation, Recovery and Recycling, Springer,
Dordrecht, The Netherlands, 2006; (c) M. Benaglia,
Recoverable and Recyclable Catalysts, John Wiley & Sons, Ltd,
Chichester, UK, 2009; (d) C. Li, Y. Liu, Bridging Heterogeneous
and Homogeneous Catalysis-Concepts, Strategies, and
Applications, Wiley–VCH, Weinheim, Germany, 2014; (e) Q.
Fan, Y. Li and A. S. C. Chan, Chem. Rev., 2002, 102, 3385; (f)
C. C. Tzschucke, C. Markert, W. Bannwarth, S. Roller, A.
Hebel and R. Haag, Angew. Chem. Int. Ed., 2002, 41, 3964; (g)
D. J. Cole-Hamilton, Science, 2003, 299, 1702; (h) W. Keim,
Green Chem., 2003, 5, 105; (i) A. Behr, G. Henze and R.
Schomäcker, Adv. Synth. Catal., 2006, 348, 1485; (j) P. Tundo
and A. Perosa, Chem. Soc. Rev., 2007, 36, 532; (k) M. J.
Muldoon, Dalton Trans., 2010, 39, 337; (l) I. V. Gürsel, T.
Noël, Q. Wang and V. Hessel, Green Chem., 2015, 17, 2012.
For reviews, see: (a) P. Wasserscheid, T. Welton, Ionic Liquids
in Synthesis, Wiley–VCH, Weinheim, Germany, 2003; (b) P. J.
Dyson and T. J. Geldbach, Metal catalysed Reactions in Ionic
Liquids, Springer, Dordrecht, The Netherlands, 2005 ; (c) C.
Hardacre and V. Parvulescu, Catalysis in Ionic Liquids: From
Catalyst Synthesis to Application, The Royal Society of
Chemistry, Cambridge, UK, 2014; (d) T. Welton, Chem. Rev.,
1999, 99, 2071. (e) P. Wasserscheid and W. Keim, Angew.
Chem. Int. Ed., 2000, 39, 3772; (f) R. Sheldon, Chem.
Commun., 2001, 2399; (g) J. Dupont, R. F. de Souza and P. A.
Z. Suarez, Chem. Rev., 2002, 102, 3667; (h) T. Welton, Coord.
Chem. Rev., 2004, 248, 2459; (i) V. I. Pârvulescu and C.
Hardacre, Chem. Rev., 2007, 107, 2615; (j) M. Haumann and
A. Riisager, Chem. Rev., 2008, 108, 1474; (k) N. V. Plechkova
3
1
3
1
P NMR (202.4 MHz, D
08.5156, calcd. for C39
2
O): δ = –5.32; HRMS (Q-ToF MS, ES+): m/z =
+
8
74
H O
14
N
3
([Ph(OCH
2
CH
2
)
14TMG] ): 808.5165; 80
+
m/z = 852.5419, calcd. for C41
78
H O
15
N
3
2
([Ph(OCH CH
2
)
15TMG] ):
852.5427;
[Ph(OCH
m/z
=
896.5681,
calcd. for
43 82 16 3
C H O N
+
(
2
CH
2
)16TMG] ): 896.5690; m/z = 940.5942, calcd. for
+
C
45 86
H O
17
N
3
([Ph(OCH
2
CH
2
)
17TMG] ): 940.5952; HRMS (Q-ToF MS,
ES–): m/z = 166.3134 (z = 3), calcd. for C18
49.9732 (z = 2), calcd. for C18 PS : 249.9735.
Evaluation of the catalyst activity and selectivity for Rh-RTP-
PolyGILs/1-octene biphasic hydroformylation system.
Rh(acac)(CO) (1.0 mg, 3.88  10 mmol), 10 equivalents of 2 (3.88
10 mmol) were added to a 60 mL autoclave under Ar 90
12 9 3
H O PS
: 166.3133; m/z = 85
2
13
H O
9
3

3
2

2

atmosphere. The Rh-catalyst was preformed by stirring the mixture
4
2
for 1 h at 100 °C and under 5.0 MPa CO/H (1:1). Then, 1  10
equivalents of 1-octene (38.8 mmol) was added using n-hexane as
an internal standard. The reaction was carried out at 100 °C and 5.0
MPa CO/H
2
for 30 min with intense stirring, and terminated by 95
cooling the autoclave in ice water. After releasing the syngas, the
upper organic phase was transferred for GC analysis.
3
Recycling the Rh-2d catalyst in the Rh-2d/1-octene biphasic

3
2
hydroformylation system. Rh(acac)(CO) (1.0 mg, 3.88  10

2
mmol), 20 equivalents of 2d (7.76  10 mmol) were added to a 60 100
mL autoclave under Ar atmosphere. The Rh-catalyst was preformed
by stirring the mixture for 1 h at 100 °C and under 5.0 MPa CO/H
2
3
(1:1). Then, 5  10 equivalents of 1-octene (19.4 mmol) was added
together with n-hexane as an internal standard. The reaction was
then carried out at 100 °C and 5.0 MPa CO/H
for 5 h with intense 105
2
stirring, and terminated by cooling the autoclave in ice water. After
releasing the syngas, the upper organic phase was decanted directly
in air and analyze by GC. The solidified 2d phase in the bottom was
replenished with fresh 1-octene for the next cycle.
This journal is © The Royal Society of Chemistry 2019
Green Chemistry, 2019, 00, 1-3 | 7

Green Chemistry
Page 8 of 9
ARTICLE
and K. R. Seddon, Chem. Soc. Rev., 2008, 37, 123; (l) H.
Green Chemistry
Organomet. Chem., 2001, 630, 177; (f) K. W. Kottsieper, O.
View Article Online
DOI: 10.1039/C9GC00518H
Olivier-Bourbigou, L. Magna and D. Morvan, Applied
Catalysis A: General, 2010, 373, 1; (m) J. P. Hallett and T.
Welton, Chem. Rev., 2011, 111, 3508; (n) F. Jutz, J. Andanson
and A. Baiker, Chem. Rev., 2011, 111, 322; (o) S. Zhang, J. 60
Sun, X. Zhang, J. Xin, Q. Miao and J. Wang, Chem. Soc. Rev.,
Stelzer and P. Wasserscheid, J. Mol. Catal. A: Chem., 2001,
175, 285; (g) R. P. J. Bronger, S. M. Silva, P. C. J. Kamera and
P. W. N. M. van Leeuwen, Dalton Trans., 2004, 1590; (h) T. E.
Kunene, P. B. Webb and D. J. Cole-Hamilton, Green Chem.,
2011, 13, 1476; (i) K. L. Luska, K. Z. Demmans, S. A. Stratton
and A. Moores, Dalton Trans., 2012, 41, 13533; (j) X. Jin, K.
Zhao, F. Kong, F. Cui and D. Yang, Catal. Lett., 2013, 143, 839;
(k) X. Jin, K. Zhao, F. Cui, F. Kong, and Q. Liu, Green Chem.,
2013, 15, 3236; (l) Y. Li, H. Liu, P. Wang, D. Yang, X. Zhao and
Y. Liu, Faraday Discuss., 2016, 190, 219; (n) Y. Li, P. Wang, H.
Liu, Y. Lu, X. Zhao and Y. Liu, Green Chem., 2016, 18, 1798.
5
0
5
0
5
0
5
0
5
0
5
2
014, 43, 7838; (p) T. L. Greaves and C. J. Drummond, Chem.
Rev., 2015, 115, 11379; (q) C. Dai, J. Zhang, C. Huang and Z.
Lei, Chem. Rev., 2017, 117, 6929; (r) R. L. Vekariya, Journal of
Molecular Liquids, 2017, 227, 44.
1
1
2
2
3
3
4
4
5
5
65
4
For reviews, see: (a) R. Ballini, Eco-Friendly Synthesis of Fine
Chemicals, The Royal Society of Chemistry, Cambridge, UK,
2
009; (b) J. H. Davis, Chem. Lett., 2004, 33, 1072; (c) S. Lee, 11 (a) M. F. Sellin, P. B. Webb and D. J. Cole-Hamilton, Chem.
Chem. Commun., 2006, 1049; (d) M. Pucheault and M.
Vaultier, Top. Curr. Chem., 2009, 290, 83; (e) R. Giernoth, 70
Angew. Chem. Int. Ed., 2010, 49, 2834; (f) A. D. Sawant, D. G.
Raut, N. B. Darvatkar and M. M. Salunkhe, Green Chem. Lett.
Rev., 2011, 4, 41; (g) C. Yue, D. Fang, L. Liu and T. Feng, J. Mol. 12 (a) P. B. Webb and D. J. Cole-Hamilton, Chem. Commun.
Liq., 2011, 163, 99.
R. A. Sheldon, Green Chem., 2017, 19, 18.
(a) A. Riisager, R. Fehrmann, M. Haumann and P.
Wasserscheid, Top. Catal., 2006, 40, 91; (b) C. Van Doorslaer, 13 For reviews, see: (a) S. Tang, G. A. Baker and H. Zhao, Chem.
J. Wahlen, P. Mertens, K. Binnemans and D. De Vos, Dalton
Trans., 2010, 39, 8377; (c) C. Chiappe and M. Malvaldi, Phys.
Chem. Chem. Phys., 2010, 12, 11191.
(a) G. Smith, D. J. Cole-Hamilton, A. C. Gregory and N. G.
Gooden, Polyhedron, 1982, 1, 97; (b) P. B. Webb, M. F. Sellin, 14 X. Jin, D. Yang, X. Xu and Z. Yang, Chem. Commun., 2012, 48,
T. E. Kunene, S. Williamson, A. M. Z. Slawin and D. J. Cole-
Hamilton, J. Am. Chem. Soc., 2003, 125, 15577.
(a) C. P. Mehnert, R. A. Cook, N. C. Dispenziere and M. 85
Commun., 2001, 781; (b) P. B. Webb, T. E. Kunene, D. J. Cole-
Hamilton, Green Chem., 2005, 7, 373; (c) C. P. Mehner, R. A.
Cook, N. C. Dispenziere and E. J. Mozeleski, Polyhedron,
2004, 23, 2679.
2004, 612; (b) A. C. Frisch, P. B. Webb, G. Zhao, M. J.
Muldoon, P. J. Pogorzelec and D. J. Cole-Hamilton, Dalton
Trans. 2007, 5531.
5
6
75
Soc. Rev., 2012, 41, 4030; (b) M. M. Cecchini, C. Charnay, F.
De Angelis, F. Lamaty, J. Martinez and E. Colacino,
ChemSusChem, 2014, 7, 45; (c) Y. Qiao, W. Ma, N. Theyssen,
C. Chen and Z. Hou, Chem. Rev., 2017, 117, 6881.
80
7
8
9017.
15 Y. Chauvin, L. Mussmann and H. Olivier, Angew. Chem. Int.
Ed. Engl., 1995, 34 (23/24), 2698.
Afeworki, J. Am. Chem. Soc., 2002, 124, 12932; (b) H. Li, P. S. 16 Z. B. Zhou, H. Matsumoto and K. Tatsumi, Chem. Eur. J.,
Bhadury, B. Song and S. Yang, RSC Advances, 2012, 2, 12525; 2005, 11, 752.
c) T. Selvam, A. Machoke and W. Schwieger, Applied 17 J. Leicunaite, I. Klimenkovs, J. Kviesis, D. Zacs and J. P.
(
Catalysis A: General, 2012, 445−446, 92; (d) B. Xin and J. Hao,
Chem. Soc. Rev., 2014, 43, 7171; (e) E. García-Verdugo, B. 9018 (a) L. V. N. R. Ganapatibhotla, J. Zheng, D. Roy and S.
Altava, M. I. Burguete, P. Lozanob and S. V. Luis, Green
Chem., 2015, 17, 2693; (f) B. Karimi, M. Tavakolian, M. Akbari
and F. Mansouri, ChemCatChem, 2018, 10 (15), 3173.
Kreišmanis, C. R. Chim. 2010, 13, 1335.
Krishnan, Chem. Mater., 2010, 22, 6347; (b) E. Kuhlmann, S.
Himmler, H. Giebelhaus and P. Wasserscheid, Green Chem.,
2007, 9, 233.
9
1
For reviews, see: (a) R. Šebesta, Enantioselective 19 (a) P. Wasserscheid and W. Keim, Angew. Chem. Int. Ed.,
Homogeneous Supported Catalysis, The Royal Society of 95
Chemistry, Cambridge, UK, 2012; (b) R. Šebesta, I. Kmentova
and Š. Toma, Green Chem., 2008, 10, 484; (c) C. Huo and T.
2000, 39, 3773; (b) H. Kawanami, A. Sasaki, K. Matsui and Y.
Ikushima, Chem. Commun., 2003, 896; (c) Q. Lin, W. Jiang, H.
Fu, H. Chen and X. Li, Appl. Catal. A, 2007, 328, 83.
H. Chan, Chem. Soc. Rev., 2010, 39, 2977; (d) B. Ni and A. D. 20 (a) P. C. J. KAMER, P. W. N. M. Van Leeuwen and J. N. H.
Headley, Chem. Eur. J., 2010, 16, 4426; (e) M. Lombardo and
C. Trombini, ChemCatChem, 2010, 2, 135; (f) J. Limberger, B. 100
C. Leal, A. L. Monteiro and J. Dupont, Chem. Sci., 2015, 6, 77.
0 (a) C. C. Brasse, U. Englert, A. Salzer, H. Waffenschmidt and
P. Wasserscheid, Organometallics, 2000, 19, 3818; (b) F. 21 P. W. N. M. Van Leeuwen and C. Claver, Rhodium Catalyzed
Favre, H. Olivier-Bourbigou, D. Commereuc and L. Saussine,
Chem. Commun., 2001, 1360; (c) P. Wasserscheid, H. 105
Waffenschmidt, P. Machnitzki, K. W. Kottsieper and O. 22 X. Jin, S. Li, K. Zhao, CN Patent 2013103701386, 2013.
Stelzer, Chem. Commun., 2001, 451; (d) R. P. J. Bronger, S. M. 23 W. L. F. Armarego and C. L. L. Chai, Purification of Laboratory
Reek, Acc. Chem. Res., 2001, 34, 895; (b) L. A. van der Veen,
P. C. J. Kamerand P. W. N. M. van Leeuwen, Angew. Chem.
Int. Ed., 1999, 38, 336; (c) R. Franke, D. Selen and A. Börner.
Chem. Rev., 2012, 112, 5675.
Hydroformylation, Kluwer Academic, Dordrecht, The
Netherlands, 2002.
Silva, P. C. J. Kamer and P. W. N. M. van Leeuwen, Chem.
Commun., 2002, 3044; (e) D. J. Brauer, K. W. Kottsieper, C.
Liek, O. Stelzer, H. Waffenschmidt and P. Wasserscheid, J.
Chemicals, 5nd Edition, Elsevier/Butterworth-Heinemann,
Burlington, MA, USA, 2003.
8
| Green Chemistry, 2019, 00, 1-3
This journal is © The Royal Society of Chemistry 2019

Page 9 of 9
Green Chemistry
View Article Online
DOI: 10.1039/C9GC00518H
•
*
A table of contents entry:
Colour graphic: maximum size 8 cm x 4 cm
*
Text: one sentence, of maximum 20 words, highlighting the novelty of the
work
Highly Effective Biphasic System for Rh-Catalyzed Hydroformylation of
1-Octene Based on Integration of Phosphine Ligand into Ionic Liquid