Bleaching Earths as Powerful Additives for Ru-Catalyzed Self-Metathesis of Non-Refined Methyl Oleate at Pilot Scale

Article abstract of DOI:10.1002/chem.201703049

A practical and cost-effective ruthenium-catalyzed self-metathesis of non-refined methyl oleate (85 %) derived from very high oleic sunflower oils was demonstrated at pilot scale using a robust and kg-scale commercially available SIPr-M71 pre-catalyst. The simple addition of 1 wt % bleaching earths (Tonsil 110FF) to a thermally pretreated oil could efficiently prevent catalyst deactivation. Remarkably, without the need for filtration, the catalytic system was able to achieve a turnover number (TON) of more than 744 000 at a catalyst loading of only 1 ppm. At large scale (up to 200 kg), the equilibrium of the self-metathesis reaction was reached within 1 hour at 50 °C under neat conditions at a very low 5 ppm catalyst loading to produce the expected primary metathesis products (PMP), that is, 9-octadecene and dimethyl-9-octadecenoate, with a productive TON of 94900.

Full text of DOI:10.1002/chem.201703049

A Journal of
Accepted Article
Title: Bleaching Earths as Powerful Additives for Ru-Catalyzed Self-
Metathesis of Non-Refined Methyl Oleate at Pilot Scale.
Authors: Marc Mauduit, Jessica Allard, Yann Raoul, Idriss Curbet,
Fabien Tripoteau, Sophie Sambou, Guillaume Chollet,
Frédéric Caijo, Christophe Crévisy, and Olivier Baslé
This manuscript has been accepted after peer review and appears as an
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of the final Version of Record (VoR). This work is currently citable by
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content of this Accepted Article.
To be cited as: Chem. Eur. J. 10.1002/chem.201703049
Link to VoR: http://dx.doi.org/10.1002/chem.201703049
Supported by

Chemistry - A European Journal
10.1002/chem.201703049
COMMUNICATION
Bleaching Earths as Powerful Additives for Ru-Catalyzed Self-
Metathesis of Non-Refined Methyl Oleate at Pilot Scale.
[
a,b]
[a]
[c]
[d]
[b]
Jessica Allard,
Idriss Curbet, Guillaume Chollet, Fabien Tripoteau, Sophie Sambou, Frédéric
[
d]
[b]
[a]
[a]
[a]
Caijo, Yann Raoul, Christophe Crévisy, Olivier Baslé and Marc Mauduit *
Dedicated to
Abstract: A practical and cost-effective ruthenium-catalyzed self-
bio-sourced lubricants, surfactants,
metathesis of non-refined methyl oleate (85%) derived from Very
High Oleic Sunflower Oils (VHOSO) was demonstrated at pilot scale
using a robust and kg-scale commercially available SIPr-M71 pre-
catalyst. The simple addition of 1 wt% bleaching earths (Tonsil
bio-sourced materials
plasticizers
O
O
[
Ru]cat
OMe
6
OMe
6
+
6
neat
MeO
1
10FF) to a thermally pretreated oil could efficiently prevent catalyst
6
6
6
Eq. (a)
deactivation. Remarkably, without the need for filtration, the catalytic
system was able to achieve a turnover number of more than 744000
at a catalyst loading of only 1 ppm. At large scale (up to 200 Kg), the
equilibrium of the self-metathesis reaction was reached within 1 hour
at 50 °C under neat conditions at a very low 5 ppm catalyst loading
to produce the expected primary metathesis products (PMP), i.e. the
O
(
Z)-1
(E/Z)-2
(E/Z)-3
[Ru]cat
(equilibrium) Eq. (b)
O
OMe
6
(E/Z)-1
6
9
-octadecene and the dimethyl-9-octadecenoate with a productive
TON of 94900.
Scheme 1. Ru-catalyzed Self-metathesis of unsaturated fatty ester methyl
oleate (Z)-1 derived from vegetable oils.
Considering the ineluctable rarefaction of fossil resources,
the catalytic transformation of biomass derivatives into valuable
fine chemicals constitutes a promising alternative, which could
by academics or industrial companies, thanks to the
development of robust and kg-scale commercially available Ru-
based catalysts (Figure 2). For instance, Ru-2b was able to
catalyze the SM of 1 at loadings as low as 1 ppm affording PMP
[
1]
be in high demands in the near future. Among the available
renewable resources, natural oils have both the advantage of
containing various reactive organic functions (e.g. alkenes,
alcohols, acids, esters) and to be currently produced at multi-
2
and 3 in 45% conversion at the equilibrium (Eq. b, Scheme 1)
with the highest turnover number (TON) of 440 000 reported so
[
2]
[3]
[
7]
million tons/year.
The self-olefin metathesis (SM)
of
far. The thienylmethylidene catalyst Ru-4 demonstrated also
unsaturated fatty acids/esters from vegetable oils represents
one of the most eco-efficient transformations with a remarkable
an impressive reactivity towards MO reaching a TON of 250
[
8]
0
00. Nevertheless, the economical viability of industrial
processes at multi-ton scale depends not only on the catalyst
[
4]
low carbon footprint. For instance, the Ru-catalyzed SM of
methyl oleate (MO) (Z)-1, derived from various oils (e.g.
soybean, canola or sunflower), produces two highly desirable
molecules (9-octadecene (E/Z)-2 and dimethyl-9-octadecenoate
[
9]
efficiency and selectivity, but also on the quality of the involved
[
2b]
raw materials.
In fact, such remarkable catalytic metathesis
activities could not be reached without requiring prior alumina
[
4]
[
10]
(
E/Z)-3) as primary metathesis products (Scheme 1). The
former can be readily converted into bio-sourced lubricants,
filtration of a costly high-purity grade of MO (>99%) , that is
incompatible with an industrial process.
[
5]
surfactants or plasticizers, while the latter is considered as a
precursor of monomers for the production of bio-sourced
[
6]
N
N
L
L
materials. In the last two decades, significant breakthroughs
have been accomplished in metathesis of oleochemicals either
Cl
Cl
Ph
Cl
Ru
Ru
Ru
Cl
Cl
Cl
PCy3
PCy3
PCy3
Ru-1 (Grubbs vinylidene)
Ru-2a L = PCy3 (Grubbs I)
Ru-2b L = SIMes (Grubbs II) Ru-3b L = SIMes (Umicore M2)
Ru-3c L = IMes (Evonik RF1)
Ru-3a L = PCy3 (Umicore M1)
[a]
Dr. J. Allard, I. Curbet, Dr. C. Crévisy, Dr. O. Baslé, Dr. M. Mauduit
Ecole Nationale Supérieure de Chimie de Rennes, UMR CNRS
L
N
N
Cl
6
226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7,
Ru
Cl
Cl
N
N
France
Ru
S
Cl
O
E-mail: marc.mauduit@ensc-rennes.fr
Dr. J. Allard, Dr. S. Sambou, Dr. Y. Raoul
OLEON SAS, Venette BP 20609, 60206 Compiègne Cedex, France
Dr. G. Chollet
Cl
PCy3
Ru-4 (Evonik RF2)
Ru
O
O
[
b]
c]
Cl
R
Ru-5a L = SIMes (Hoveyda-Grubbs II)
Ru-5b L = SIPr
NH
[
ITERG, 11 rue Monge – Parc industrie Bersol 2, 33600 Pessac,
France
Dr. F. Tripoteau, Dr. F. Caijo
N
N
N
N
SIMes =
IMes =
Ru-6a R = CF3 (Umicore M71)
Ru-6b R = Oi-Bu (Umicore M73)
N
N
SIPr =
[d]
DEMETA SAS, 6 rue Pierre-Joseph Colin, 35000 Rennes, France
Supporting information for this article is given via a link at the end of
the document.
Figure 1. Benchmark of kg-scale commercially available Ru-1-6 pre-catalysts
commonly used in metathesis of oleochemicals.
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Chemistry - A European Journal
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COMMUNICATION
Because the pre-treatment of the oleo-raw materials represents
a key success factor for a cost-effective metathesis process,
Some are naturally present (Np1-3), some are formed during the
hydrolysis (Hp1-2) or during the esterification process (Ep1-3) to
produce fatty acid/esters, and some are resulting from
decomposition by oxidation and/or polymerization (Dp1-3).
Because, each of them can act as a potential poison towards
either the ruthenium pre-catalyst or the catalytic active species,
we decided to investigate their influence onto the rate of the SM
reaction (figure 3 and SI).
[
11]
many efforts have been made to address this concern.
Several methodologies to trap catalyst poisoning species
present in vegetable oils (e.g. peroxides, phosphates, sulfates,
soap…) were reported with varying degrees of success. The use
of reductive reagents, inorganic bases or metallic alcoholates
followed by successive aqueous washes and then filtration
through
a sorbent such as activated charcoal, alumina,
[
12]
magnesium silicate or celite proved to be efficient.
The
O
thermal pre-treatment (100 °C) of methyl fatty esters under
vacuum in combination with small amounts of a mix of sorbents
AcO
O
7
7
O
O
O
O
N
P
O
1
4
3
3
3
(
magnesium silicate/celite) represents the most effective
O
O
sunflower lecithine Np1
α-tocophérol acetate Np2
process to date, allowing after filtration, the metathesis reaction
[
12d]
R1
with less than 10 ppm of catalyst loadings (with Ru-1).
However, due to a noticeable loss of the raw material during the
filtration (up to 20 wt.%), all these pretreatments would have
significant impact on the total cost of production. Therefore, the
development of a simple, ton-scalable, and cost-effective olefin
metathesis process for the conversion of renewable fatty esters
is still in high demands. Herein, we report an efficient ruthenium-
catalyzed self-metathesis process to convert non-refined MO 1
R
1
=
;
;
;
;
HO
Sterols Np3
OH
OH
O
OH
OH
OH
O
O
R2
O
O
OH
Glycerol Ep1
O Ep2
OH
2
2
6
R
R
O
O
O
O
O
6
O
O
O
H
2
R2
R2
R2
Oleic acid Hp1
(
85%) derived from Very High Oleic Sunflower Oils (VHOSO)
MeOH Ep3
O
mono-, bis- or triglycerides Hp2
2
into corresponding PMP 2 and 3 at pilot scale using a robust
(
R = (un)-saturated linear akylchain)
[
13]
commercially available M71 complex Ru-6a
in presence of
6
n-Nonanal Dp1
O
R
4
O
O
R
3
O
O
R
4
O
O
bleaching earths as additives to prevent the catalyst deactivation.
O
O
O
5
6
We initiated our study by evaluating in self-metathesis a
R
3
O
O
O
R
3
HOO
6
6
10
7
7
5
[
14]
OMe
refined oil containing 94% of methyl oleate (Z)-1, derived from
two successive recrystallizations in acetone (at -37 and -60 °C,
respectively) of the VHOSO raw material (scheme 2). Without
any pre-treatment, up to 0.05 mol% (500 ppm) of Ru-6a was
needed to convert 89% of (Z)-1 within 15 min at 50 °C under
neat condition and to reach the equilibrium (Eq. b), affording 2
6
O
O
O
O
O
O
6
Standolie Dp3
4
(R3
=
= Z,Z-(CH2)7CH=CH-CH=CH(CH2)4CH3
Z-(CH2)7CH=CH(CH2)7CH3; R )
peroxidized MO Dp2
Figure 2. Benchmark of molecules frequently present in fatty esters (Np:
natural products; Hp: hydrolysed products; Ep: products from esterification;
Dp: decomposed product)
[
15]
and 3 in 20 and 22 wt%, respectively. A significant amount of
methyl elaidate (E)-1 was also formed (41 wt%, see ESI for
details). It is also important to note that below a catalyst loading
of 400 ppm, no reactivity was observed. This result clearly
demonstrated that, despite the robustness and high stability of
6
O
Ru-6 (0.05 mol%)[a]
O
6
(
E/Z)-2
Ru-6
Additives (10 wt%)
OMe
OMe
6
6
O
+
neat, 50 °C, time.
Eq. (b)
[
13]
6
6
the M71 pre-catalyst,
the presence of certain substrate
6
OMe
(
Z)-1
(E/Z)-1
MeO
impurities has a dramatic effect on catalyst efficiency. Therefore,
with the objective to reach an optimal catalytic process, it
appeared important to us to clearly identify these poisons and to
adapt accordingly. A large variety of organic molecules can be
found in vegetal oils (Figure 2).
from refined
VHOSO (94%)
6
O
(E/Z)-3
(a)
(b)
6
0ꢀ
50ꢀ
0ꢀ
6
0ꢀ
50ꢀ
0ꢀ
0ꢀ
[ b ]
[ b ]
4
41.5
4
w t %
w t %
3
/
3
0
ꢀ
3 /
3
2
2
2
0ꢀ
20ꢀ
10ꢀ
0ꢀ
2
2
1
0ꢀ
none
Dp3
Dp2
Dp1
1
9.5
none
0
ꢀ
17
Hp1
Hp2
2ꢀ
2ꢀ
6ꢀ
6ꢀ
6
10ꢀ
time (min.)
15ꢀ
10ꢀ
15ꢀ
30ꢀ
20ꢀ
time (min.)
O
6
O
(
E/Z)-2 (20 wt%)[b,c]
Ru-6
Ru-6 (0.05 mol%)
OMe
OMe
Figure 3. Kinetic profiles of the SM of MO (Z)-1 catalyzed by Ru-6a in
presence of additives Hp (a) and Dp (b). [a] Conditions: Ru-6a (0.05 mol%),
additive (10 wt%), 50 °C, neat. [b] Percentage per weight of 2/3 in the crude,
determined by GC (see ESI).
6
6
O
+
neat, 50 °C, 15 min.
Eq. (b)
6
9% conv. [a]
6
8
OMe
6
(
Z)-1
(E/Z)-1 (50 wt%)[b]
MeO
from refined
VHOSO (94%)
6
(E/Z)-3 (22 wt%)[b,c]
O
While the voluntary contamination with 10 wt% of lecithine (Np1),
a-tocopherol acetate (Np2), sterols Np3 or Ep1-3 (i.e. Glycerol,
water and methanol) had no effect on the rate of the metathesis
reaction (see ESI for details), a noticeable effect was observed
after the addition of by-products resulting from the hydrolysis of
Scheme 2. Self-metathesis of MO (Z)-1 derived from refined VHOSO (94% of
purity) catalyzed by SIPr-M71 Ru-6a. [a] Conversion of (Z)-1, monitored by GC
(
see ESI for details). [b] Percentage per weight of the composition of the crude
at the equilibrium, determined by GC (see ESI). [c] E/Z ratio = 4/1.
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Chemistry - A European Journal
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COMMUNICATION
triglycerides (Figure 3-a). In fact, both oleic acid Hp1 and a mix
of glycerides Hp2 have significantly slowed down the reaction
rate, reaching respectively a maximum of 20 and 22 wt% of
PMP 2/3 after 30 min. A similar behavior was observed with
products originating from the fatty esters oxidation (Figure 3-b).
Peroxidized methyl oleate Dp2 allowed to reach the equilibrium
in 20 min. and only 17 wt% of PMP were obtained in the
presence of n-nonanal Dp1. Lastly, no detrimental effect
occurred with standolie Dp3 as additive.
with 10 wt% bleaching earth (50 °C, 15 min.) allowed to reach
the equilibrium within 1 hour at extremely low 0.0005 mol%
catalyst loading (5 ppm, entry 3). Taking into account its
abrasive nature that may damage the stainless-steel reactor at
pilot scale, we decided to further diminish the amount of the
bleaching earth. The optimal conditions were later found by
increasing the time contact between the sorbent and the starting
material (up to 120 min). With 1 wt% of the bleaching earth, the
equilibrium of metathesis was reached with an extremely low
[
20]
The bleaching operation is part of the refining process of crude
oils to achieve high quality oil standards for edible applications.
The properties of bleaching earths allow for the removal of
numerous impurities including oxidation products, resulting in
lower peroxide and anisidine values. Extracted from quarries,
these natural earths with high adsorption capacity are abundant,
loading of Ru-6a (0.0005 mol%, entry 6). Remarkably, under
these conditions, the catalyst remained active at 1 ppm loading,
converting 65% of the non-refined MO (Z)-1 to achieve an
impressive TON of 744000 and a related productive TON of
359000 (entry 7). This is the first time a catalytic system has
exhibited such high performance in a self-metathesis reaction of
[
16]
[8]
cheap and commercially available,
which make them
methyl oleate.
particularly suited to an industrial application of the Ru-catalyzed
SM of methyl oleate. The expected beneficial effect of bleaching
earth was confirmed after filtration of the refined oil (94% of
O
Pre-treatment 1
85 °C
6
O
1
OMe
[
16b]
6
methyl oleate) on Tonsil Supreme 110FF®
(100 wt%), as the
10 mbar, 2 h
Ru-6 (x mol%)
6
Ru-6
OMe
(E/Z)-2
6
O
equilibrium could be reached with 0.01 mol% of Ru-6a (Table 1,
entry 1). Nevertheless, 5% of methyl oleate was lost during the
filtration process and we therefore considered performing the
metathesis reaction in presence of the bleaching earth.
neat, 50 °C, time
+
Tonsil 110FF
y wt%), 50 °C
15 min.
Eq. (b)
6
(
OMe
6
6
(
Z)-1
MeO
from non-refined Pre-treatment 2
6
VHOSO (85%)
(E/Z)-1
O
(E/Z)-3
Pre-
traitment 1
Tonsil 110FF Ru-6
(wt%)
time
Conv.
2/3
TON[f] TONp[g]
Entry
[a]
[b]
(mol%)[c] (min.) (%)[d] (wt%)
[e]
1
2
3
4
5
none
none
none
10
10
3
0.06
15
15
60
60
60
90
97
88
89
90
43
43
43
43
43
1570
5060
850
method A
0.02
2700
Filtration on
O
6
tonsil 110FF
100 wt%)
with
with
with
with
with
0.0005
0.001
0.002
202100 115400
O
(
OMe
Ru-6 (x mol%)[b]
6
Ru-6
6
102100
51600
57400
28500
94700
OMe
Pre-treatment[a]
(E/Z)-2
6
O
1
neat
50 °C, 15 min.
+
Eq. (b)
6
tonsil 110FF
OMe
6
7
1 (120 min.)
1 (120 min.)
0.0005
0.0001
60
60
90
65
43
27
172500
(10 wt%)
6
6
(
Z)-1
5
0 °C, 15 min.
no filtration
MeO
744000 359000
from refined
6
VHOSO (94%)
(E/Z)-1
TON[e] TONp[f]
O
(E/Z)-3
method B
Table 2. Optimization of bleaching earth pre-treatments towards non-refined
MO (Z)-1 prior SM catalyzed by Ru-6a. [a] 185 °C, 10 mbar, 2 h. [b] Tonsil
Entry Pre-traitment [a] Ru-6 (mol%)
Conv. (%)[c]
2/3 (wt%)[d]
1
10FF (y wt%), 50 °C, 15 min. [c] Ru-6a (x mol%), 50 °C, neat. [d]
1
2
Method A
Method B
0.0100
0.0015
89.5
83.5
47
48
8750
4850
Conversions of (Z)-1, monitored by GC (see ESI for details). [e] Percentage
per weight of 2/3 in the crude, determined by GC (see ESI). [f]
TON=conv.×(initial moles of (Z)-1/moles of catalyst)/100. [g] productive TON
of 2+3=(moles of 2 + 3)/(moles of catalyst).
53000
32300
Table 1. Chemical pre-treatments of refined MO (Z)-1 with bleaching earths
prior SM catalyzed by Ru-6a. [a] Method A: Filtration of (Z)-1 on Tonsil 110FF
(
(
100 wt%); Method B: (Z)-1, Tonsil 110FF (10 wt%), 50 °C, 15 min. [b] Ru-6a
x mol%), 50 °C, neat, 15 min. [c] Conversions of (Z)-1, monitored by GC (see
ESI for details) [d] Percentage per weight of 2/3 in the crude, determined by
GC (see ESI). [e] TON=conv.×(initial moles of (Z)-1/moles of catalyst)/100. [f]
productive TON of 2+3=(moles of 2 + 3)/(moles of catalyst).
Intrigued by this remarkable efficiency to trap poisons from the
crude oil without any noticeable detrimental side effects on the
catalytic activity, we decided to investigate the interaction
between the bleaching earth and the ruthenium catalyst.
Surprisingly, when Ru-6a (0.002 mol%) was pre-mixed with
tonsil 110FF (1 wt%), no metathesis transformation of MO
occurred (Scheme 3, a). A similar inactivity was also observed at
higher catalyst loading (0.1 mol%). Moreover, the total lack of
activity was confirmed in an attempt to perform the ring-closing
metathesis (RCM) of 1,7-octadiene 4 (Scheme 3, b). As Tonsil
Interestingly, the treatment of the oil with 10 wt% of tonsil 110FF
over 15 min followed by the introduction of Ru-6a led the
metathesis reaction to readily reach the equilibrium even with a
catalyst loading as low as 0.0015 mol% (15 ppm) and a TON of
5
3000 (Table 1, entry 2). These improved results, prompted us
to apply this methodology to a non-refined VHOSO oil containing
[
21]
[
17]
110FF is mainly composed by silica (75.5%), we suspected a
rapid impregnation of the ruthenium catalyst, as depicted in
scheme 3. Indeed, after dissolving Ru-6a in dichloromethane
8
5% of methyl oleate (Radia 7072®),
a ton-scale available
[
18]
raw material suitable for industrial scale-up.
Nevertheless,
probably due to an important level of peroxide detected in the
(
picture A), the green color fully disappeared after the addition of
starting material in comparison with the refined oil (28 vs 3.2
[
19]
the bleaching earth (10 wt%, picture B). The resulting colorless
supernatant was then used in SM of (Z)-1 or RCM of 4 and
showed no metathesis activity, attesting the complete
impregnation of the catalyst with the tonsil. Moreover, the
meq O
necessary to reach the equilibrium of the self-metathesis (Table
, entry 1). Fortunately, a simple thermic heating at 185 °C
under vacuum (10 mbar) over 2 hours followed by the treatment
2
/Kg, respectively),
up to 0.02 mol% of catalyst was
2
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Chemistry - A European Journal
10.1002/chem.201703049
COMMUNICATION
[
22]
impregnated catalyst was also inactive.
On the other hand,
With this cost-effective and efficient pretreatment condition
in hands, the SM of non-refined MO (Z)-1 was re-investigated
with alternative commercially available complexes Ru-2,3 and
Ru-5,6 (Figure 5). Under our condition, first generation catalysts
when the tonsil 110FF is mixed with the non-refined oil prior the
addition of the catalyst (picture C), the resulting supernatant
remained green (picture D) and displayed good catalytic activity
in metathesis of 4 (>99% within 5 min, see ESI for details). All
these experiments showed that the bleaching earth is able to
3
bearing PCy ligands (Ru-2a,3a) were totally inactive. While
second generation complexes bearing the SIMes ligand (Ru-
2b,3b) displayed poor activities to produce 13 to 15 wt% of PMP
2/3, no reactivity was observed with Evonik catalyst Ru-3c
bearing the unsaturated IMes ligand. On the other hand,
phosphine-free complexes Ru-5,6 appeared more robust
demonstrating relatively similar levels of efficiency (40 to 43 wt%
of PMP 2/3).
[
23]
rapidly deactivate the ruthenium complex but becomes totally
inert toward the catalyst after the adsorption of impurities
contained in a non-ultra-pure oil.
Pre-treatment[a]
O
6
O
1
85 °C
Ru-cat
OMe
1
0 mbar, 2 h
(0.0015 mol%)[b]
6
(E/Z)-2
Ru-cat
6
OMe
6
O
+
Tonsil 110FF
1 wt%), 50 °C
2 h
neat, 50 °C, 1 h
MeO
Eq. (b)
OMe
6
(
6
6
(
Z)-1
from non-refined
VHOSO (85%)
6
(E/Z)-3
O
(E/Z)-1
4
0
41
42
43
c ]
w t %
3
/
2
1
3
15
Scheme 3. Deactivation of the Ru-6a catalyst by impregnation onto Tonsil
1
10FF bleaching earth.
-
2a
-
3a
u
3c
R
u
u-3b
R
I
R
u-2b
5a
s
u-6b
R
b
M1
R
-
5b
b
ru
I
u-6a
R
RF1 Ru- M2
I
Ru
G
bbs
ru
3
G
1
HG II Ru- M7
We continued our optimization study by screening alternative
commercially available sorbents (Figure 4). Introduced at 1 wt%,
most of the sorbents allowed for modest catalytic activity with 20
ppm of Ru-6a. For instance, under our conditions, the use of
magnesium silicate (magnesol® D60) which has been widely
M7
G
Pr-H
SI
Figure 5. Screening of commercially available catalysts Ru-2-3 and Ru-5-6 in
the SM of non-refined MO (Z)-1. [a] Conditions: 185 °C, 10 mbar, 2 h then
sorbent (1 wt%), 50 °C, 2 h. [b] Conditions: Ru-catalyst (0.0015 mol%), 50 °C,
neat, 1 h. [c] Percentage per weight of 2/3 in the crude, determined by GC
(see ESI).
[
12d]
employed in oil pre-treatment
led to a low production of 14
wt% PMP 2/3. Durcal 2, Trisyl or Flucat 22B showed better
efficiency, but with up to 29 wt% of 2/3 in the best case. The
optimal production of PMP 2/3 was obtained with bleaching
earths Tonsil 110FF and 112FF as well as the less cost-
attractive silica hydrogel trisyl 300. Therefore, we chose to
pursue our study with the cheap Tonsil 110FF.
SIPr-M71 Ru-6a, which afforded the highest conversion, was
selected for the scale-up development of the transformation
(Table 3). The first attempt at 1 Kg scale was performed using
0.01 mol% of Ru-6a. After the thermic treatment, the non-refined
MO was reacted with 1%wt of Tonsil 110FF at 50 °C. The media
turned rapidly brown with a slight exothermic reaction (10 °C).
After the addition of Ru-6a, the equilibrium was reached within
15 min with 83.5% conversion, affording PMP 2 and 3 in 39 wt%
(entry 1). We next attempted the metathesis at 3 Kg scale with
0.0005 mol% of catalyst (5 ppm). The excellent conversion with
a high TON of 189000 observed after 1 h attested for the
robustness of the pretreatment and prompted us to perform a
pilot-scale production (200kg). In a 300 L reactor, the addition of
Pre-treatment[a]
6
O
O
1
85 °C
OMe
1
0 mbar, 2 h Ru-6 (0.002 mol%)[b]
6
(E/Z)-2
Ru-6
6
OMe
6
O
then sorbent neat, 50 °C, 15 min.
1 wt%), 50 °C
15 min.
+
Eq. (b)
6
(
OMe
6
6
(
Z)-1
MeO
from non-refined
6
VHOSO (85%)
O
(E/Z)-1
(E/Z)-3
c
]
43
43
43
w t %
29
3
/
25
Tonsil 110FF, preceded by
a
thermic pretreatment that
/Kg,
2
3
2
11
14
11
decreased the peroxide content from 18 to 0.09 meq O
2
1
allowed for an excellent olefin metathesis performance, as the
equilibrium was reached within 15 min converting the non-
0
0
0
0
B8
2
0
0
6
t
4
2
l
luca
t
loo
l
D
syl
B
2
0
uca
rca
ri
0
F
l
F
so
u
T
2
3
F
refined MO (Z)-1 in 88% (entry 3, see the kinetic profile in
F
e
D
t
12F
F
re
Pu
n
ulca
syl
ri
10F
g
1
[24]
T
l
1
l
Ma
F
si
ESI).
Importantly, no evolution of the equilibrium was
n
si
n
o
T
o
T
observed over 5 h leading to PMP 2 and 3 in 41 wt%. Therefore,
a remarkable TON of 174000 was reached at the equilibrium,
with a productive TON of 94900.
Figure 4. Screening of sorbents for the pretreatment of non-refined MO (Z)-1
prior SM catalyzed by Ru-6a. [a] Condition: 185 °C, 10 mbar, 2 h then sorbent
(
1 wt%), 50 °C, 15 min. [b] Condition: Ru-6a (0.002 mol%), 50 °C, neat, 1 h. [c]
Percentage per weight of 2/3 in the crude, determined by GC (see ESI).
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Chemistry - A European Journal
10.1002/chem.201703049
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Pre-treatment [a]
O
[2]
[3]
179 millions tons per year have been produced in 2015/2016, see: J.
Spekreijse, J. P. M. Sanders, J. H. Bitter, E. L. Scott, ChemSusChem
2017, 10, 470 and references cited therein.
6
O
1
85 °C
(E/Z)-2
OMe
10 mbar, 2 h
Ru-6a (x mol%)[b]
neat, 50 °C, time
Ru-6a
6
OMe
6
6
O
+
Tonsil 110FF
1 wt%), 50 °C
Eq. (b)
6
Selected comprehensive books on olefin metathesis: (a) R. H. Grubbs,
A. G. Wenzel, D. J. O’Leary, E. Khosravi, (Eds.) Handbook of
(
OMe
6
6
(
Z)-1
2
h
MeO
O
from non-refined
VHOSO (85%)
6
nd
(E/Z)-3
Metathesis, 2 Edition; Wiley-VCH: Weinheim, Germany, 2015; (b) K.
(
E/Z)-1
Grela (Ed.), Olefin Metathesis: Theory and Pratice, Wiley-VCH:
Weinheim, Germany, 2014.
Conv.
2/3
(wt%)
TON[e]
[f]
Entry
Scale-up Ru-6a (mol%) time (min.)
TON
p
[
c]
[d]
(%)
[
4]
[5]
6]
[7]
For a review, see: A. Rybak, P. A. Fokou, M. A. R. Meier, Eur. J. Lip.
Sci. Technol. 2008, 110, 797.
1
2
3
1 Kg
0.01
15
60
83.5
88
39
42
41
8300
189000
174000
4500
104300
94900
3 Kg
200 Kg[g]
0.0005
0.0005
(a) Y.-M. Choo, K.-E. Ooi, I.-H. Ooi, D. D. H. Tan, J Am Oil Chem Soc.
300
88
1
996, 73, 333; (b) W. Keim, Angew. Chem. Int. Ed. 2013, 52, 12492.
M. A. R. Meir, J. O. Metzger, U. S. Schubert, Chem. Soc. Rev., 2007,
6, 1788. See also ref. 4.
[
Table 3. Scale-up development of SM of non-refined MO (Z)-1 catalyzed by
Ru-6a. [a] Conditions: 185 °C, 10 mbar, 2 h then sorbent (1 wt%), 50 °C, 2 h.
b] Ru-6 (x mol%), 50 °C, neat. [c] Conversions of (Z)-1, monitored by GC (see
ESI for details). [d] Percentage per weight of 2/3 in the crude, determined by
GC (see ESI). [e] TON=conv.×(initial moles of (Z)-1/moles of catalyst)/100. [f]
productive TON of 2+3=(moles of 2 + 3)/(moles of catalyst). [g] Tonsil 110FF
reacted with MO over 2 h 30.
3
[
M. B. Dinger, J. C. Mol, Adv. Synth. Catal. 2002, 344, 671.
R. Kadyrov, C. Azap, S. Weidlich, D. Wolf, Top. Catal. 2012, 55, 538.
See for instance: M. Rouen, P. Queval, E. Borré, L. Falivene, A. Poater,
M. Berthod, F. Hugues, L. Cavallo, O. Baslé, H. Olivier-Bourbigou, M.
Mauduit, ACS Catal. 2016, 6, 7970.
[
[
8]
9]
[
[
[
10] Extra-pure methyl oleate (>99%) is commercialized by Aldrich (62€/5 g).
11] S. Chikkali, S. Mecking, Angew. Chem. Int. Ed. 2012, 51, 5802.
12] (a) D. W. Lemke, K. D. Uptain, F. Amore, T. Abraham, PCT Int. Appl.
WO 2009/020667; (b) Z. Lysenko, B. R. Maughon, J. Bicerano, K. A.
Burdett, C. P. Christenson, C. H. Cummins, M. L. Dettloff, J. M. Maher,
A. K. Schrock, P. J. Thomas, R. D. Varjian, J. E. White, PCT Int. Appl.
WO 2003/093215; (c) S. A. Cohen, D. R. Anderson, Z. Wang, T. M.
Champagne, T. A. Ung, US Pat. 2014/0275681; (d) K. D. Uptain, C.
Tanger, H. Kaido, PCT Int. Appl. WO 2009/020665.
In conclusion, an efficient, practical and cost-effective
pretreatment through the use of cheap bleaching earths was
proposed to mediate the ruthenium-catalyzed self-metathesis of
non-refined methyl oleate (Z)-1 (85% of purity) derived from
Very High Oleic Sunflower Oils at very low catalyst loading. The
use of commercially available bleaching earth Tonsil 110FF® (1
wt%) combined with a thermic pretreatment enabled to trap all
poisons presents in the raw material without any requirement of
filtration prior the metathesis. With a catalytic loading of 0.0005
mol% (5 ppm) of SIPr-M71 pre-catalyst, non-refined (Z)-1 was
converted in up to 90% within 1 hour at 50 °C under neat
conditions and the expected primary metathesis products, the 9-
[
[
13] M71-SIPr is commercialized by Umicore company (www.umicore.com).
For the related publication, see: H. Clavier, F. Caijo, E. Borré, D. Rix, F.
Boeda, S. P. Nolan, M. Mauduit, Eur. J. Org. Chem. 2009, 25, 4254.
14] The other compounds were identified as saturated and mono- or poly-
unsaturated fatty methyl esters: C14:0 (0.02 wt.%); C14:1 (0.01 wt.%);
C16:0 (2.7 wt.%); C16:1 (0.03 wt.%); C18:0 (1.3 wt.%); C18:2 (1.6
wt.%); C22:0 (0.06 wt.%) and C22:1 (0.2 wt.%).
octadecene
2 and the dimethyl-9-octadecenoate 3, were
[
[
[
15] The kinetic profile of the reaction showed that the equilibrium was
reached within 4 min (See ESI for details).
produced in 43 wt%. Importantly, the catalytic system remained
active as low as 1 ppm enabling reaching 65% conversion with
the highest TON of 744000. The robustness of the catalytic
process has proven to be also efficient at pilot-scale (up to 200
Kg) with an impressive productive TON of 94900. Application of
this efficient and scalable pre-treatment protocol is currently
investigated to other valuable and challenging metathesis
transformations of non-refined vegetable oils, such as
16] (a) For more information, see: Oils&Fats International, june 2016, 32(5),
pp 26-31; (b) Tonsil® bleaching earths are commercialized by Clariant.
17] Radia 7072® is commercialized by Oleon company. The other
compounds were identified as saturated and mono- or poly-unsaturated
fatty methyl esters: C16:0 (3.4 wt.%); C16:1 (0.1 wt.%); C18:0 (1.8
wt.%); C18:2 (3.1 wt.%); C18:3 (1.8 wt.%); C20:0 (0.2 wt.%) C22:0 (0.3
wt.%) and C22:1 (0.7 wt.%).
[
2]
[
[
18] The recrystallization process leading to a better quality of raw material
alkenolysis of fatty ester/acids.
(
i.e. 94%) appeared too costly and inappropriate at industrial scale.
19] The peroxide value is defined as the amount of peroxide oxygen per 1
kilogram of oil and is determined by measuring the amount of iodine
which is formed by the reaction of peroxides with iodide ion.
Acknowledgements
[
[
20] Composition of the crude after filtration: (Z/E)-2 (15.7 wt.%), (Z/E)-3
(
27.2 wt.%), (E)-1 (26.6 wt.%), (Z)-1 (8.2 wt.%).
This work was supported by the Agence Nationale de la
Recherche (ANR-12-CD2I-0002 CFLOW-OM). MM thanks
Rennes Métropole and the Région-Bretagne (SAD n°8734) for
their financial supports concerning the development of Ru-based
complexes. We are grateful to the ANRT and Oléon (Grant to I.C.
and J.A., CIFRE n° 2012/0182), the CNRS and the ENSCR.
21] Composition of Tonsil Supreme 110FF® (average values): SiO
2
(
(
75.5%), Al
2 3 2 3 2
O (12%), Fe O (2.4%), CaO (0.4%), MgO (1.4%), Na O
0.3%), K O (1%).
2
[
[
22] SIPr-M71 impregnated onto amorphous silica has proved to be quite
efficient in olefin metathesis, see: H. Nasrallah, D. Dragoe, C. Magnier,
C. Crévisy, M. Mauduit, E. Schulz, ChemCatChem 2015, 7, 2494.
23] (a) Additional experiments were done showing the detrimental effect of
2 3
a mixture of metallic oxides (Fe O , CaO and MgO) towards the Ru-
Keywords: Olefin Metathesis • ruthenium• oleochemicals •
catalyst (see ESI for details). For previous studies reporting the catalyst
decomposition by oxidation, see: (b) D. W. Knight, I. R. Morgan, A. J.
Proctor, Tetrahedron Lett. 2010, 51, 638. (c) M. Mauduit, F. Caijo, C.
Crévisy, PCT Int. Appl. WO 2009/0805403; (d) A. Jana, K. Grela, Org.
Lett. 2017, 19, 520.
bleaching earths • pilot production
[
1]
Report of the United Nations Conference on Environmental
Development, Rio de Janeiro (Brazil) http://www.un.org/esa/sustdev,
Accessed 1992
[24] Composition of the crude after filtration: (Z/E)-2 (15.8 wt.%); (Z/E)-3
25.4 wt.%); (E)-1 (38.5 wt.%); (Z)-1 (10.2 wt.%).
(
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Chemistry - A European Journal
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COMMUNICATION
COMMUNICATION
[
a,b]
[a]
[d]
[d]
[a]
Jessica Allard,
Idriss Curbet,
[
c]
b]
Guillaume Chollet, Fabien Tripoteau,
[
Sophie Sambou,
Frédéric Caijo,
[
b]
Yann Raoul,
Christophe Crévisy,
[
a]
[a]
Olivier Baslé and Marc Mauduit
*
Page No. – Page No.
An efficient and cost-effective pretreatment was proposed to mediate the Ru-
catalyzed self-metathesis of non-refined methyl oleate (Z)-1 (85%) derived from
Very High Oleic Sunflower Oils (VHOSO). The use of bleaching earths (Tonsil
Bleaching
Earths
as
Powerful
Additives for Ru-Catalyzed Self-
Metathesis of Non-Refined Methyl
Oleate at Pilot Scale.
1
10FF, 1 wt%) combined with a thermic pretreatment enabled metathesis under
neat conditions with a catalytic loading as low as 0.0001 mol% (1 ppm) and
impressive turnover number (TON) of 744000. The robust catalytic process has
proven to be efficient at pilot scale (200 Kg) with a remarkable productive TON
(
94900) for expected primary metathesis products 9-octadecene 2 and dimethyl-9-
octadecenoate 3.
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