Transfer-hydrogenation reactions of ketones/aldehydes in water using first generation ruthenium indenylidene olefin metathesis catalyst: One step towards sequential cross-metathesis/transfer hydrogenation reactions

Article abstract of DOI:10.1016/j.mcat.2019.110640

The transfer hydrogenation reactions of various ketones/aldehydes and one-pot cross-metathesis/transfer hydrogenation (CM/TH) reactions of 10-undecenal were carried out in water media using first generation ruthenium-indenylidene complex (M1). A stable emulsion with an average particle size of 23.00 (±7.20) nm was formed in water media using non-ionic (Tween 20) and cationic (dodecyltrimethylammonium chloride) surfactants in the presence of acetophenone, M1 (1%) and sodium formate, yielding corresponding alcohol derivatives in quantitative yields. The performance of M1 (5%) was tested on sequential cross-metathesis/transfer hydrogenation reaction of 10-undecenal using methyl acrylate as the cross-metathesis partner in water. The sequential CM/TH reaction of 10-undecenal was found to proceed even in tap water under air atmosphere using micellar catalyst system, giving the corresponding CM/TH product in 65% yield.

Full text of DOI:10.1016/j.mcat.2019.110640

MolecularCatalysis480(2020)110640
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Molecular Catalysis
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Transfer-hydrogenation reactions of ketones/aldehydes in water using first
generation ruthenium indenylidene olefin metathesis catalyst: One step
towards sequential cross-metathesis/transfer hydrogenation reactions
Bengi Özgün Öztürk⁎, Sinem Öztürk
Hacettepe University, Faculty of Science, Chemistry Department, 06800, Beytepe, Ankara, Turkey
A R T I C L E I N F O
A B S T R A C T
Keywords:
The transfer hydrogenation reactions of various ketones/aldehydes and one-pot cross-metathesis/transfer hy-
drogenation (CM/TH) reactions of 10-undecenal were carried out in water media using first generation ruthe-
nium-indenylidene complex (M1). A stable emulsion with an average particle size of 23.00 ( 7.20) nm was
formed in water media using non-ionic (Tween 20) and cationic (dodecyltrimethylammonium chloride) sur-
factants in the presence of acetophenone, M1 (1%) and sodium formate, yielding corresponding alcohol deri-
vatives in quantitative yields.
Transfer hydrogenation
Cross-metathesis
Ruthenium indenylidene
Aqueous media
10-undecenal
One-pot reaction
Emulsion
The performance of M1 (5%) was tested on sequential cross-metathesis/transfer hydrogenation reaction of
10-undecenal using methyl acrylate as the cross-metathesis partner in water. The sequential CM/TH reaction of
10-undecenal was found to proceed even in tap water under air atmosphere using micellar catalyst system,
giving the corresponding CM/TH product in 65% yield.
1. Introduction
efficient catalyst candidates in transfer hydrogenation of alkenes in-
cluding tandem metathesis /transfer hydrogenation reactions were
Transfer hydrogenation (TH) of ketones and aldehydes is an effi-
cient method to produce alcohols in a mild one-step procedure [1,2].
The discovery of transfer hydrogenation procedures eliminated the di-
rect use of hydrogen gas which is hard to handle and allowed hydro-
genation reactions to proceed using inexpensive chemicals such as
formic acid, isopropyl alcohol, sodium formate instead of hydrogen gas.
Various transition metals such as iron, ruthenium, osmium, cobalt,
rhodium, iridium, nickel, palladium, gold and their complexes were
used as efficient catalysts in transfer hydrogenation reactions [2]. The
discovery of ruthenium-based Noyori catalyst [3,4] has opened a new
era in transfer hydrogenation reactions, thus expanding the industrial
application portfolio. Ruthenium-based olefin metathesis catalysts, that
are tolerant to air and various functional groups, have gained tre-
mendous interest in both industry and academia. In addition to superior
performance of Grubbs type catalysts in olefin metathesis reactions,
these ruthenium based complexes can also catalyze various non-meta-
thetic reactions including isomerization, hydrogenation, cyclopropa-
nation, hydrosilylation of terminal alkynes, carboxylic acid addition to
alkynes, alkyne dimerization, alkyne cyclotrimerization, carbonyl de-
hydrogenation and deprotection of N-allyl amines [5–9]. In the last
decade, the potential of Grubbs and Hoveyda-Grubbs type complexes as
evaluated by several research groups [10–16].
Although sequential hydrogenation/transfer hydrogenation of al-
kenes are known in the literature, only a few studies have reported
efficient protocols for the transfer hydrogenation of ketones using
Grubbs type complexes [17,18]. Carrasco et al. utilized Grubbs type
catalysts along with chiral amine ligands for the one-pot cross-me-
tathesis (CM) /asymmetric transfer hydrogenation (ATH) reactions of
unsaturated ketones in isopropyl alcohol/THF [18]. Although water
compatible protocols for ruthenium catalyzed transfer hydrogenation
reactions are well known in the literature [19–23], the performance of
Grubbs type olefin metathesis catalysts on transfer hydrogenation of
ketones/aldehydes in aqueous media yet to be explored. Herein, for the
first time, we report the activity of ruthenium indenylidene complex
(M1) on transfer hydrogenation of ketones/aldehydes in water. One-pot
cross-metathesis/transfer hydrogenation (CM/TH) sequence was de-
monstrated using 10-undecenal; and methyl acrylate as the cross-me-
tathesis partner. The catalytic system under micellar conditions ex-
hibited high performance even in non-degassed tap water under air
atmosphere (close vessel) yielding the corresponding CM/TH product in
65% yield.
⁎ Corresponding author.
E-mail address: bengi04@hacettepe.edu.tr (B.Ö. Öztürk).
https://doi.org/10.1016/j.mcat.2019.110640
Received 15 August 2019; Received in revised form 16 September 2019; Accepted 18 September 2019
2468-8231/©2019ElsevierB.V.Allrightsreserved.

B.Ö. Öztürk and S. Öztürk
MolecularCatalysis480(2020)110640
Table 1
Transfer hydrogenation reactions of acetophenone.
Entrya
Catalyst
Additives
Temperature (°C)
Reaction time
Conversion %
1
M1
M1
M1
–
HCOONa
25
50
85
85
85
85
85
84
24 h
24 h
12 h
12 h
24 h
24 h
24 h
24 h
0
2
HCOONa
10
3
HCOONa
99 (95)c
0
4d
5
HCOONa
M1
M1
M1
M1
HCOOH/KOHb
HCOONa/KOHb
HCOOH
45 (43)c
46 (42)c
25
6
7
8e
HCOONa
18
a
A Schlenk reactor was charged with deionized water (10 ml), Tween 20 (T20, 0.1 g) and dodecyltrimethylammonium chloride (DTMAC, 0.4 g) and stirred at
1000 rpm using a magnetic stirrer at 85 °C under nitrogen atmosphere. M1 (0.01 g, 0.0108 mmol) that was dissolved in acetophenone (126.40 μL, 1.08 mmol) added
dropwise to the stirring solution of T20 and DTMAC in water. Sodium formate (4.32 mmol, 0.294 g) was then added to the reaction mixture to initiate transfer
hydrogenation reaction. Aliquots taken from the reaction mixture was extracted with diethyl ether and dried using MgSO4. The samples were then analyzed by
GC–MS using n-tetradecane as the internal standard.. The samples were then analyzed by GC–MS using n-tetradecane as the internal standard.
b
c
d
e
HCOOH/KOH: 1/1; HCOONa/KOH; 1/1.
Isolated yields.
The reaction was carried out in the absence of M1.
The reaction was carried out without any surfactants (both Tween 20 and DTMAC).
2. Results & discussion
given as the average of three experiments. In method A, M1 was dis-
solved in acetophenone and then dropwise added to a stirring solution
of 1% Tween 20 and 4% DTMAC solution in water. After ten minutes of
intense stirring at 1000 rpm, sodium formate was added to the reactor
to initiate the reaction. In method B, acetophenone was added to a
stirring solution of 1% Tween 20 and 4% DTMAC in water and stirred at
1000 rpm for ten minutes to stabilize the emulsion. M1, that was dis-
solved in a minimum amount of toluene, was added dropwise to the
emulsion solution and stirred for five minutes in order to homo-
geneously disperse the catalyst in the emulsion. After that sodium for-
mate was added to the reactor to initiate the reaction. In method C,
acetophenone and sodium formate were added to a stirring solution of
1% Tween 20 and 4% DTMAC, and stirred for ten minutes. M1, that
was dissolved in toluene, was then added to the reaction mixture to
initiate the reaction.
The activity of ruthenium indenylidene complex; (Dichloro(3-
phenyl-1H-inden-1-ylidene)bis(tricyclohexylphosphine)ruthenium(II)
(M1), was tested in transfer hydrogenation reactions of acetophenone
in water in the presence of cationic (dodecyltrimethyl ammonium
chloride; DTMAC) and non-ionic (Tween 20) surfactants. The hydro-
genation reactions of acetophenone were carried out using formic acid
(HCOOH), sodium formate (HCOONa), HCOOH/KOH and HCOONa/
KOH and results are given in Table 1.
Firstly, a stable emulsion of acetophenone/M1 was formed using 1%
Tween 20 (wt. %) and 4% DTMAC (wt. %) in water under constant
stirring at 1000 rpm. Secondly, sodium formate (HCOONa) was added
to the reactor and the reactor was stirred at 85 °C under nitrogen at-
mosphere. The complete conversion of acetophenone to 1-phenyl
ethanol was confirmed by GC–MS analysis after 12 h. The reaction was
repeated under identical reaction conditions using HCOOH/KOH,
HCOONa/KOH, and HCOOH but no significant improvement in means
of conversion was observed (Table 1). A blank test without M1 was
carried out to test the possible contribution of the base on transfer
hydrogenation reactions since metal-free transfer hydrogenation pro-
tocols in the presence of 2-propanol were reported in the literature
[24,25]. As it can be seen in Table 1 (Entry 4), transfer hydrogenation
reaction didn’t proceed in the absence of M1.
In method A, a stable emulsion with an average particle size of
23.00 ( 7.20) nm, as confirmed by dynamic light scattering (DLS)
analysis, was formed in water media. Following the complete conver-
sion of acetophenone, the emulsion retained its stability and the
average particle size of the emulsion slightly increased up to 37.43
Table 2
Average emulsion particle size in the presence of different Tween 20/DTMAC
ratio.
On the next trial, the effect of the reactant addition order was tested
on the performance of M1 catalyzed transfer hydrogenation reactions of
acetophenone (Fig. 1). All reactions were triplicated and results were
Entry Tween 20 (wt. %) DTMAC (wt. %) Average partice
Conversion %b
size (nm) ( std.
dev.)a
1
2
3
4
1
–
5
4
4
5
–
1
23.00 ( 7.20)
29.25 ( 7.28)
28..37 ( 7.74)
26.32 ( 8.87)
99
85
75
80
a
b
DLS results were given in supporting information section (SI, Fig. S1-4).
The reaction was carried out using pre-determined reaction conditions at
Fig. 1. The effect of reactant addition order on transfer hydrogenation of
85 °C for 12 h. Conversions were determined by GC–MS using n-tetradecane as
the internal standard.
acetophenone.
2

B.Ö. Öztürk and S. Öztürk
MolecularCatalysis480(2020)110640
Table 3
Table 4
Transfer hydrogenation of acetophenone using different ruthenium initiators.
Transfer hydrogenation reactions of various ketones/aldehydes using M1 as the
catalyst in water media.
Substratesa
Conversion %
Substrates
Conversion %
86
99
Entrya
Catalyst
Solvent
Conversion %
92
95
90
1
2
3
4
5
6
7
8
9
[RuCl2(p-cymene)]2
H2O
H2O
H2O
H2O
H2O
H2O
H2O
H2O
H2O
55
70
5
G1
G2
G3
0
85b
M1
99
19
17
5
M2
HG2
Zhan
Aquamet
4
90
88
a
A Schlenk reactor was charged with deionized water (10 ml), Tween 20
(T20, 0.1 g) and dodecyltrimethylammonium chloride (DTMAC, 0.4 g) and
stirred at 1000 rpm using a magnetic stirrer at 85 °C. M1 (0.01 g, 0.0108 mmol)
that was dissolved in acetophenone (126.40 μL, 1.08 mmol) added dropwise to
a stirring solution of T20 and DTMAC in water. Sodium formate (4.32 mmol,
0.294 g) was then added to the reaction mixture to initiate transfer hydro-
genation reaction. Aliquots taken from the reaction mixture was extracted with
diethyl ether and dried using MgSO4. The samples were then analyzed by GC-
–MS using n-tetradecane as internal standard. (0.01 g, 0.0108 mmol) that was
dissolved in acetophenone (126.40 μL, 1.08 mmol) added dropwise to a stirring
solution of T20 and DTMAC in water. Sodium formate (4.32 mmol, 0.294 g) was
then added to the reaction mixture to initiate transfer hydrogenation reaction.
Aliquots taken from the reaction mixture was extracted with diethyl ether and
dried using MgSO4. The samples were then analyzed by GC–MS using n-tetra-
decane as internal standard.
92
70
90
92
a
A Schlenk reactor was charged with deionized water (10c ml), Tween 20
(T20, 0.1 g) and dodecyltrimethylammonium chloride (DTMAC, 0.4 g) and
stirred at 1000 rpm using a magnetic stirrer at 85 °C. M1 (0.01 g, 0.0108 mmol)
that was dissolved in corresponding aldehyde/ketone (126.40 μL, 1.08 mmol)
added dropwise to a stirring solution of T20 and DTMAC in water. Sodium
formate (4.32 mmol, 0.294 g) was then added to the reaction mixture to initiate
the transfer hydrogenation reaction. Aliquots taken from the reaction mixture
was extracted with diethyl ether and dried using MgSO4. The samples were
then analyzed by GC-–MS using n-tetradecane as an internal standard. (0.01 g,
0.0108 mmol) that was dissolved in corresponding aldehyde/ketone
(126.40 μL, 1.08 mmol) added dropwise to a stirring solution of T20 and
DTMAC in water. Sodium formate (4.32 mmol, 0.294 g) was then added to the
reaction mixture to initiate the transfer hydrogenation reaction. Aliquots taken
from the reaction mixture was extracted with diethyl ether and dried using
MgSO4. The samples were then analyzed by GC–MS using n-tetradecane as an
internal standard. b: M1 and ferrocenecarboxaldehyde (solid) were dissolved in
500 μL toluene.
(
5.94) nm. (Please see supporting information, SI, Fig. S1-4). The
reaction was repeated using different non-ionic/cationic surfactant ra-
tios (Tween 20/DTMAC) and the average particle sizes and the con-
version values of acetophenone on transfer hydrogenation are given in
Table 2
As summarized in Table 2, the combination of Tween 20/DTMAC in
1/4 ratio afforded relatively smaller micelle structures in water, thus
providing more isolated hydrophobic sites and it is important to note
that the conversion rates are strictly depended on DTMAC/Tween 20
ratios. When compared to the reactions that were carried out solely
with Tween 20, it is possible that DTMAC stabilizes the catalytic active
species more efficiently than non-ionic surfactants during the TH
Scheme 1. Various ruthenium catalysts that were used for transfer hydrogenation of acetophenone in water media.
3

B.Ö. Öztürk and S. Öztürk
MolecularCatalysis480(2020)110640
Table 5
Cross-metathesis/transfer hydrogenation of 10-undecanl.
Time (h)
Conversion %a
Yield %b
Method A
Method B
24
24
80
90
75
85
a
b
Conversion (%) was based on amount of 10-undecenal. n-tetradecane was used as an internal standard.
GC yield.
reaction. In method A, the reaction was initiated through the diffusion
aromatic ketones displayed excellent reactivity in transfer hydrogena-
tion reactions using M1 under identical reaction conditions. Aldehyde
derivatives (4-fluoro-benzaldehyde, benzaldehyde, ferrocenecarbox-
aldeyde, citral) were successfully converted to corresponding alcohols
of sodium formate to the micelle center bearing M1 and acetophenone.
After 12 h, acetophenone was completely converted to 1-phenyl
ethanol. In method B, the reaction proceeded more slowly due to the
diffusion limitations of both M1 and sodium formate to the micelle
center bearing acetophenone. The diffusion limitation was more ap-
parent in method C, thus the conversion value was decreased down to
35% in transfer hydrogenation of acetophenone.
derivatives. 5-norbornene-2-carboxaldehyde (endo,exo mixture),
a
well-known ring opening metathesis monomer, was selectively con-
verted to 5-norbornene-2-methanol and no oligomeric/polymeric pro-
duct was formed during the reaction as confirmed by GCeMS and size-
exclusion chromatography (SEC) analysis. These results indicated that
ring-opening metathesis polymerization was completely suppressed in
the presence of sodium formate during transfer hydrogenation reac-
tions.
The performances of commercially available ruthenium complexes
including 2nd generation ruthenium indenylidene complex (M2),
Grubbs 1st (G1), 2nd (G2) and 3rd (G3) generation, Hoveyda-Grubbs 2nd
(HG2) generation catalysts as well as Zhan catalyst (Zhan) and
Aquamet and [RuCl2(p-cymene)]2 were tested in transfer hydrogena-
tion reactions of acetophenone using pre-determined reaction condi-
tions and results are given in Table 3 (Scheme 1).
In order to expand the scope of the study, the sequential CM/TH of
10-undecenal; a bifunctional unsaturated aldehyde, was examined
under identical reaction conditions. 10-undecenal, which is obtained
from castor oil, is a green platform chemical and a suitable cross-me-
tathesis reagent for the synthesis of various functional products.
[29–31] (Table 5).
First-generation Grubbs catalysts (G1, M1) outperformed the ana-
logs of second-generation Grubbs and Hoveyda-Grubbs catalysts (G2,
HG2, Zhan, Aquamet) in transfer hydrogenation reactions of acet-
ophenone in water, reaching conversion values up to 99% (M1) and
70% (G1) These activity differences between first and second-genera-
tion Grubbs catalysts in transfer hydrogenation reactions can be ex-
plained on the basis of ruthenium hydride formation kinetics. As re-
ported by Fogg et al., the reaction rates for the formation of ruthenium
hydride species using PCy3 is relatively higher when compared to NHC
containing second-generation Grubbs complexes [26].
On the first trial, the cross-metathesis reaction of 10-undecenal and
methyl acrylate was carried out using 5% M1 in aqueous Tween 20/
DTMAC solution (Scheme 2). Two different methods (A-CM and B-CM)
were used to introduce catalyst M1 into the reaction mixture to opti-
mize the reaction conditions for cross-metathesis reactions in water. In
method A-CM, a mixture of 10-undecenal/methyl acrylate was added
dropwise to an aqueous solution of Tween 20/DTMAC under con-
tinuous stirring at room temperature. In a separate reactor, 5% M1 that
was dissolved in a minimum amount of toluene was added dropwise to
a water solution of T20/DTMAC and then two reaction mixtures were
mixed and stirred at 30 °C for 12 h. Samples regularly withdrawn from
the reaction mixture were extracted with diethyl ether and analyzed by
GC–MS. A maximum conversion value of 80% was obtained (GC yield
for CM product is 75%). In method B-CM, 10-undecenal, methyl acry-
late and M1 (5%) were rapidly dissolved in a minimum amount of to-
luene at 0 °C to suppress the metathesis reactions before dispersing the
mixture in aqueous media. The resulting mixture was added dropwise
to a stirring solution of T20/DTMAC at 1000 rpm in water at 30 °C.
After 12 h, the final product was obtained in 85% yield (GC-yield). No
self-metathesis product of 10-undecenal was obtained during the cross-
On the next trial, the performance of the catalytic system was tested
on transfer hydrogenation reactions of different ketones (acetophenone,
4-methyl-acetophenone,
2-methyl-acetophenone,
4-chloro-acet-
ophenone, 4-fluoro-acetophenone) and aldehydes (benzaldehyde, 4-me-
thyl-benzaldehyde,4-fluoro-benzaldehyde, ferrocenecarboxaldehyde, 5-
norbornene-2-carboxaldehyde, citral, 10-undecenal) using pre-de-
termined reaction conditions in water and results are given in Table 4.
As it can be seen in Table 4, the catalyst system exhibited high
functional group tolerance and no significant reactivity difference was
observed between ortho and para-substituted isomers of methylaceto-
phenone (2-methylacetophenone and 4-methylacetophenone). Halogen
groups are known as activating groups for transfer hydrogenation re-
actions in the literature [27,28]. Halogen substituted (-Cl and –F)
Scheme 2. Cross-metathesis/transfer hydrogenation reactions of 10-undecenal.
4

B.Ö. Öztürk and S. Öztürk
MolecularCatalysis480(2020)110640
Table 6
One-pot CM/TH reactions of 10-undecenal and methyl acrylate.
Atmospherea
Time
Conversion %b
Yield %c
Degassed deionized water
N2
Air
N2
Air
N2
Air
24
24
24
24
24
24
99
99
99
99
99
99
72
68
70
68
67
65
Non-degassed
deionized water
Tap water
(non-degassed)
a
b
c
The reaction was carried out in closed vessels.
Based on the amount of 10-undecenal.
Isolated yield.
metathesis reaction. The cross-metathesis reaction yielded pre-
dominantly trans configured product (95% trans) as determined by GC
analysis.
References
[1] F. Foubelo, C. Nájera, M. Yus, Catalytic asymmetric transfer hydrogenation of ke-
tones: recent advances, Tetrahedron Asymmetry 26 (2015) 769–790.
[2] D. Wang, D. Astruc, The golden age of transfer hydrogenation, Chem. Rev. 115
(2015) 6621–6686.
Following the successful cross-metathesis reaction between 10-un-
decenal and methyl-acrylate, one-pot CM/TH reaction of 10-undecenal
was investigated under air and nitrogen atmosphere using degassed and
non-degassed deionized water and tap water to demonstrate the per-
formance of the catalytic system under harsh reaction conditions
(Table 6). The cross-metathesis reaction was initiated at 30 °C using
method B-CM and once the conversion rate of the reaction reached a
plateau (approximately after 12 h), the temperature was raised to 85 °C
and sodium formate was added to initiate the transfer-hydrogenation
reaction.
[3] S. Hashiguchi, A. Fujii, J. Takehara, T. Ikariya, R. Noyori, Asymmetric transfer
hydrogenation of aromatic ketones catalyzed by chiral ruthenium(II) complexes, J.
Am. Chem. Soc. 117 (1995) 7562–7563.
[4] R. Noyori, S. Hashiguchi, Asymmetric transfer hydrogenation catalyzed by chiral
ruthenium complexes, Acc. Chem. Res. 30 (1997) 97–102.
[5] B. Alcaide, P. Almendros, A. Luna, Grubbs’ ruthenium-carbenes beyond the me-
tathesis reaction: less conventional non-metathetic utility, Chem. Rev. 109 (2009)
3817–3858.
[6] B.Ö. Öztürk, S. Karabulut, Y. İmamoğlu, Activity of homobimetallic ruthenium al-
kylidene complexes on intermolecular [2+2+2] cyclotrimerisation reactions of
terminal alkynes, Inorg. Chim. Acta 378 (2011) 257–263.
Although 99% of 10-undecenal was consumed after 24 h of initial
reaction time, the maximum isolated yield of CM/TH product was
found to be 72% (Table 6, Entry 1). 10-undecen-1-ol and isomerization
products of 10-undecenal were formed during the reaction as the by-
products of the reaction. Cross-metathesis and cross-metathesis/
transfer hydrogenation products 1H NMR data that were obtained for
compounds 1 and 2 (Scheme 2) were consistent with the previous lit-
erature studies [30–32].
[7] S. Karabulut, B.Ö. Öztürk, Y. İmamoğlu, Ru-mediated selective addition reactions of
carboxylic acids to internal and terminal alkynes, J. Organomet. Chem. 695 (2010)
2161–2166.
[8] M. Arisawa, Y. Terada, K. Takahashi, M. Nakagawa, A. Nishida, Non‐metathesis
reactions of ruthenium carbene catalysts and their application to the synthesis of
nitrogen‐containing heterocycles, Chem. Rec. 7 (2007) 238–253.
[9] W.A.L. van Otterlo, E.M. Coyanis, J.L. Panayides, C.B. de Koning, M.A. Fernandes,
Tandem catalysis: a ring-closing metathesis followed by dehydrogenative oxidation
to afford substituted indenones, Synlett 3 (2005) 501–505.
[10] B. Schmidt, Catalysis at the interface of ruthenium carbene and ruthenium hydride
chemistry: organometallic aspects and applications to organic synthesis, Eur. J. Org.
Chem. 2004 (2004) 1865–1880.
3. Conclusion
[11] R. Kusy, K. Grela, E- and Z-Selective transfer semihydrogenation of alkynes cata-
lyzed by standard ruthenium olefin metathesis catalysts, Org. Lett. 18 (2016)
6196–6199.
In this study, we showed that emulsion of M1 in the presence of non-
ionic/ionic surfactant system is an efficient catalyst system for transfer
hydrogenation of various ketones/aldehydes in aqueous media. A
variety of different ketones/aldehydes were quantitatively converted
into corresponding alcohols derivatives using the micellar catalytic
system in aqueous media. The one-pot sequential CM/TH reactions of
10-undecenal and methyl acrylate selectively yielded (E)-methyl-12-
hydroxydodec-2-enoate (2). The catalyst system exhibits high perfor-
mance even under harsh reaction conditions and the corresponding
CM/TH product (2) obtained in 65% yield under air atmosphere in tap
water (72% under nitrogen atmosphere). We believe that this en-
vironmentally friendly sequential CM/TH process will expand the scope
of olefin metathesis applications for the synthesis of key molecules from
renewable sources
[12] G.K. Zielinski, C. Samojlowicz, T. Wdowik, K. Grela, In tandem or alone: a re-
markably selective transfer hydrogenation of alkenes catalyzed by ruthenium olefin
metathesis catalysts, Org. Biomol. Chem. 13 (2015) 2684–2688.
[13] G.K. Zielinski, J. Majtczak, M. Gutowski, K. Grela, A selective and functional group-
tolerant ruthenium-catalyzed olefin metathesis/transfer hydrogenation tandem se-
quence using formic acid as hydrogen source, J. Org. Chem. 83 (2018) 2542–2553.
[14] K.D. Camm, N.M. Castro, Y. Liu, P. Czechura, J.L. Snelgrove, D.E. Fogg, Tandem
ROMP−hydrogenation with a third-generation grubbs catalyst, J. Am. Chem. Soc.
129 (2007) 4168–4169.
[15] T. Connolly, Z. Wang, M.A. Walker, I.M. McDonald, K.M. Peese, Tandem ring-
closing metathesis/transfer hydrogenation: practical chemoselective hydrogenation
of alkenes, Org. Lett. 16 (2014) 4444–4447.
[16] B. Schmidt, S. Krehl, V. Sotelo-Meza, Synthesis of chromanes through RCM–transfer
hydrogenation, Synthesis 44 (2012) 1603–1613.
[17] J. Louie, C.W. Bielawski, R.H. Grubbs, Tandem catalysis: the sequential mediation
of olefin metathesis, hydrogenation, and hydrogen transfer with single-component
Ru complexes, J. Am. Chem. Soc. 123 (2001) 11312–11313.
[18] M. Renom-Carrasco, P. Gajewski, L. Pignataro, J.G. de Vries, U. Piarulli, C. Gennari,
L. Lefort, Asymmetric transfer hydrogenation of ketones with modified grubbs
metathesis catalysts: on the way to a tandem process, Adv. Synth. Catal. 358 (2016)
515–519.
Acknowledgments
[19] X. Wu, J. Xiao, Aqueous-phase asymmetric transfer hydrogenation of ketones – a
greener approach to chiral alcohols, Chem. Commun. (2007) 2449–2466.
[20] X. Wu, X. Li, W. Hems, F. King, J. Xiao, Accelerated asymmetric transfer hydro-
genation of aromatic ketones in water, Org. Biomol. Chem. 2 (2004) 1818–1821.
[21] X. Li, X. Wu, W. Chen, F.E. Hancock, F. King, J. Xiao, Asymmetric transfer hydro-
genation in water with a supported noyori-ikariya catalyst, Org. Lett. 6 (2004)
3321–3324.
We would like to thank Prof. Dr. Adil DENİZLİ and Semra Akgönüllü
for their help with dynamic light scattering (DLS) analysis.
Appendix A. Supplementary data
[22] S. Ogo, T. Abura, Y. Watanabe, pH-dependent transfer hydrogenation of ketones
with HCOONa as a hydrogen donor promoted by (η6-C6Me6)Ru complexes,
Organometallics 21 (2002) 2964–2969.
Supplementary material related to this article can be found, in the
online version, at doi:https://doi.org/10.1016/j.mcat.2019.110640.
5

B.Ö. Öztürk and S. Öztürk
MolecularCatalysis480(2020)110640
[23] S. Baldino, S. Facchetti, H.G. Nedden, A.Z. Gerosa, W. Baratta, Chemoselective
transfer hydrogenation of aldehydes with HCOONH4 catalyzed by RuCl(CNNPh)
(PP) pincer complexes, ChemCatChem 8 (2016) 3195–3198.
[28] S. Denizaltı, D. Mercan, B. Şen, A.G. Gökçe, B. Çetinkaya, Asymmetric transfer
hydrogenation reaction in water: comparison of chiral proline amide/amine ru-
thenium(II) complexes, J. Organomet. Chem. 779 (2015) 62–66.
[29] M. Van der Steen, C.V. Stevens, Y. Eeckhout, L. De Buyck, F. Ghelfi, F. Roncaglia,
Undecylenic acid: a valuable renewable building block on route to Tyromycin A
derivative, Eur. J. Lipid Sci. Technol. 110 (2008) 846–852.
[24] A. Ouali, J.-P. Majoral, A.-M. Caminade, M. Taillefer, NaOH-promoted hydrogen
transfer: does NaOH or traces of transition metals catalyze the reaction?
ChemCatChem. 1 (2009) 504–509.
[25] M.C. Carrión, F.A. Jalón, B.R. Manzano, A.M. Rodríguez, F. Sepủlveda, M. Maestro,
(Arene)ruthenium(II) complexes containing substituted bis(pyrazolyl)methane li-
gands – catalytic behaviour in transfer hydrogenation of ketones, Eur. J. Inorg.
Chem. (2007) 3961–3973.
[30] X. Miao, C. Fischmeister, C. Bruneau, P.H. Dixneuf, A direct route to bifunctional
aldehyde derivatives via self- and cross-metathesis of unsaturated aldehydes,
ChemSusChem 2 (2009) 542–545.
[31] X. Miao, A. Blokhin, A. Pasynskii, S. Nefedov, S.N. Osipov, T. Roisnel, C. Bruneau,
P.H. Dixneuf, Alkylidene-ruthenium-tin catalysts for the formation of fatty nitriles
and esters via cross-metathesis of plant oil derivatives, Organometallics 29 (2010)
5257–5262.
[26] N.J. Beach, J.A.M. Lummiss, J.M. Bates, D.E. Fogg, Reactions of grubbs catalysts
with excess methoxide: formation of novel methoxyhydride complexes,
Organometallics 31 (2012) 2349–2356i.
[27] Y. Xie, M. Wang, X. Wu, C. Chen, W. Ma, Q. Dong, M. Yuan, Z. Hou, A pH-re-
sponsive soluble-polymer-based homogeneous ruthenium catalyst for highly effi-
cient asymmetrictransfer hydrogenation (ATH), ChemPlusChem 81 (2016)
541–549.
[32] M. Winkler, L. Montero de Espinosa, C. Barner-Kowollik, M.A.R. Meier, A new
approach for modular polymer–polymer conjugations via Heck coupling, Chem. Sci.
3 (2012) 2607–2615.
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