Reductive amination of ethyl levulinate to pyrrolidones over AuPd nanoparticles at ambient hydrogen pressure

Article abstract of DOI:10.1039/c9gc00396g

Herein, we describe a AuPd catalyst for selective and solventless conversion of ethyl levulinate (EL) and amines to pyrrolidones under ambient pressure. The optimized Au₆₆Pd₃₄ nanoparticle catalyst was stable and reusable over 10 runs. AuPd catalysis was extended to reductive amination of levulinic acid and 4-acetylbutyric acid, providing a green chemistry approach under milder conditions not only to pyrrolidones, but also to piperidines, both of which are important scaffolds in designing polymers, natural products and pharmaceuticals.

Full text of DOI:10.1039/c9gc00396g

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DOI: 10.1039/C9GC00396G
Green Chemistry
COMMUNICATION
Reductive amination of ethyl levulinate to pyrrolidones over AuPd
nanoparticles at ambient hydrogen pressure
a
a
a
a
a
b
c
Michelle Muzzio, Chao Yu, Honghong Lin, Typher Yom, Dilek A. Boga, Zheng Xi, Na Li,
Received 00th January 20xx,
Accepted 00th January 20xx
a
a
a
Zhouyang Yin, Junrui Li, Joshua A. Dunn, Shouheng Sun*
DOI: 10.1039/x0xx00000x
www.rsc.org/
7
Herein, we describe a AuPd catalyst for selective and solventless formation. In almost all reported metal-catalyzed conversions,
conversion of ethyl levulinate (EL) and amines to pyrrolidones pressurized (5-55 atm) hydrogen (H
2
,6,8
)
and moderate
of which the use of
is especially worrisome as it leads not only to
4
under ambient pressure. The optimized Au66Pd34 nanoparticle temperatures (90 - 180 ˚C) are required,
catalyst was stable and reusable over 10 runs. AuPd catalysis was pressurized H
2
extended to reductive amination of levulinic acid and 4- safety concerns, but also to undesirable side reactions, lowering
acetylbutyric acid, providing a green chemistry approach under the reaction selectivity.
milder conditions not only to pyrrolidones, but also to piperidines,
Recently, we demonstrated that Pd-based nanoparticles
both of which are important scaffolds in designing polymers, (NPs) can serve as very active catalysts for the hydrolysis of
natural products and pharmaceuticals.
ammonia borane (AB, NH
generate H
3
BH
3
) and formic acid (FA, HCOOH) to
9
2
under ambient conditions. When Pd was alloyed
Biomass is a class of renewable organic materials containing
cellulose, hemicellulose and lignin that come from wood and
agricultural crops. It is a conventional source of energy that has
been utilized for ages and has recently been restudied as a
sustainable source of fuels or value-added chemicals. Biomass
can be hydrolyzed in acid to produce platform chemicals like
with Ag or Au, the alloy NPs showed very interesting catalysis
not only for the dehydrogenation of AB and FA to produce H
2
,
but also for the tandem hydrogenation of a nitro-compound to
primary amine, which can further be converted to a cyclic
10
benzoxazole when reacted with an aldehyde. This AgPd or
AuPd catalyzed cyclization to form benzoxazoles, along with
1
levulinic acid (LA) and furfural. Further selective conversion of
11
other studies on AgPd or AuPd catalysis, inspired us to study
these platform chemicals to more useful value-added chemicals
their abilities in catalyzing the reductive amination of EL to
pyrrolidones using 1 atm H .
2
2
is essential for biomass conversion to be practical. One class of
such value-added chemicals are pyrrolidones that can be
obtained from the reductive amination of LA or its ester
derivative ethyl levulinate (EL). Pyrrolidones are useful not only
as solvents and surfactants, but also as precursors for preparing
fiber and pharmaceutical chemicals.
Conventional methods used to convert LA/EL to
pyrrolidones require the presence of Pt- and Ru-based
Here we report our studies on AuPd NP catalyzed reductive
amination of EL. We prepared 3.8 nm AuPd NPs on simple car-
bon support and found their catalysis for the reductive
amination reaction was Au/Pd composition dependent. The
Au66Pd34 alloy NPs were the most active and stable for the
reactions between primary amines and EL, forming pyrrolidones
3
2
under 1 atm H at 85 ˚C with the reaction turnover frequency
catalysts.4 Pd-based catalysts coupled with ZrO
-5
have also
TOF) reaching as high as 200 mol mol-1metal
-1
2
(
h and isolated
6
been studied for the LA, but not EL, conversion to pyrrolidones.
Some efforts have been made in acid-catalyzed metal-free
conversions, but require harmful solvents like DMSO or
acetonitrile to be successful as well as autogenous pressure
product yields > 90%. The AuPd catalysis could be further
extended to the reductive amination of LA/4-acetylbutyric acid
to pyrrolidone/piperidine derivatives. Our study demonstrates
an exciting new AuPd NP catalytic approach for the reductive
amination of EL or LA/4-acetylbutyric acid to
aDepartment of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
pyrrolidones/piperidines under ambient H
2
pressure.
Email: ssun@brown.edu
Monodispersed 3.8 nm AuPd alloy NPs were synthesized as
b
12
Department of Chemistry, University of Central Florida, Orlando, Florida 32816,
reported. Palladium acetylacetonate (Pd(acac)
2
) and gold
USA.
tetra-chloroaurate (HAuCl ) were co-reduced with borane
4
c
Frontier Institute of Science and Technology jointly with the College of Science,
morpholine in oleylamine. The compositions of the alloy NPs
Xi’an Jiaotong University, Xi'an, Shaanxi Province, 710054, China.
Electronic Supplementary Information (ESI) available: [details of any supplementary
information available should be included here]. See DOI: 10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
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were controlled by the amount of metal precursors added and fcc patterns of the as-synthesized Au Pd , C-Au Pd , and the
6
6
34
66View3 4A rticle Online
were measured by inductively coupled plasma−atomic emission
DOI: 10.1039/C9GC00396G
AA-washed C-Au66Pd34 (Figure 1D). The alloy structure of the C-
NPs after AA-washing was further characterized by high-angle
annular dark field (HAADF) scanning TEM (STEM) and electron
energy-loss spectroscopy (EELS), showing indeed AuPd is
present as an alloy (Figure 1E).
We first screened the reaction between EL and octylamine to
form 5-methyl-1-octylpyrrolidin-2-one over C-AuPd with or without
solvent under 1 atm H
Table S1). We found solventless at 85 ˚C to be ideal to form the
pyrrolidone with > 90% yield after 12 h reaction time. Under the
same 1 atm H and 85 ˚C, C-Au showed no activity for the pyrrolidone
2
balloon at different reaction temperatures
(
2
formation after 48 h reaction time. C-Pd was moderately active,
giving 62% yield after 48 h of reaction. We further studied Au/Pd
composition dependent catalysis and obtained turnover frequency
(
TOF) of the reaction by measuring the amount of pyrrolidone
formed over a set period with the same metal mol% (Figure 2). Figure
A shows the pyrrolidone formation yield in a 12 h reaction period
2
when different C-NP catalysts were present with constant metal
mol%. Figure 2B is the calculated pyrrolidone formation TOFs of the
different C-NP catalysts studied. We can see that C-Au is inactive and
C-Pd is moderately active, but not as active as C-AuPd. When Pd is
alloyed with Au, its catalytic activity is improved. The most active
Figure 1. Characterization of Au66Pd34 NPs. (A) TEM image of the as-synthesized
3
.8 ± 0.4 nm Au66Pd34 NPs, (B) HR-TEM image of the Au66Pd34 NP on carbon after
acetic acid washing, (C) TEM image of the acetic acid washed C-Au66Pd34, (D) XRD
patterns of Au66Pd34, C-Au66Pd34, and acetic acid washed C-Au66Pd34 compared
with ICSD standards for Au (ICSD 52249, red) and Pd (ICSD 52251, purple), and (E)
HAADF-STEM image of a selected Au66Pd34 NP and STEM-EELS elemental mapping
to show Pd (green) and Au (red) distribution within the NP.
spectroscopy (ICP−AES). As a control, 4.5 nm Pd NPs (Figure S1A)
or 4 nm Au NPs (Figure S1B) were also prepared by the
reduction of Pd(acac)
tetralin/oleylamine with borane tert-butylamine. Figure 1A
and Figure S2A-C show the transmission electron microscope
2
in oleylamine or HAuCl
4
in
1
3
(TEM) images of as-synthesized 3.8 ± 0.4 nm Au66Pd34 and other
Au24Pd76 (3.7 ± 0.4 nm), Au40Pd60 (3.8 ± 0.4 nm), and Au84Pd16
(
(
4.1 ± 0.4 nm) NPs. Figure 1B shows the high-resolution TEM
HR-TEM) image of a single Au66Pd34 NP; the (111) spacing was
measured to be 0.231 nm, which is smaller than that of face-
centered cubic (fcc) Au (0.235 nm) and larger than that of fcc Pd
(
0.223 nm).14 The x-ray diffraction (XRD) patterns of AuPd NPs
are similar to those of the fcc structured Au (ICSD 52249) and
Pd (ICSD 52251) with the (111) peaks of all the AuPd alloys
falling between those of pure Au and Pd (Figure S2D). Further,
the plasmonic absorbance of Au disappears upon its alloying
with Pd, indicating that AuPd forms a well-alloyed system rather
1
5-16
than core-shell architecture (Figure S3).
As-synthesized NPs were loaded onto carbon support (C)
and treated with acetic acid (AA) overnight to remove
oleylamine, denoted as C-AuPd, or C-Au, or C-Pd. Figure 1C
shows the C-Au66Pd34 NPs after AA washing with 15 wt% NP
loading; the AA treatment does not change the size and
morphology of the NPs. XRD analyses further indicate that the
alloy fcc structure is maintained during the processes of NP
deposition on C and the AA washing, as evidenced by the stable
Figure 2. Catalytic data for Au/Pd NPs of varying compositions. (A) Time-
dependent formation of 5-methyl-1-octylpyrrolidin-2-one on different C-Au, C-Pd,
and C-AuPd NPs, and (B) TOF values of the formation of 5-methyl-1-
2
| J. Name., 2012, 00, 1-3
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octylpyrrolidin-2-one on different C-NPs. The reaction condition: EL = 3 mmol,
octylamine = 3 mmol, catalyst = 0.3 mol%, 1 atm H , 85 ˚C. Pyrrolidone yield was
calculated from NMR using mesitylene as the internal standard.
catalyzed ammonia borane (AB) methanolysis. Our work
demonstrates an efficient use of C-Au66Pd34 catalyst for dual
View Article Online
DOI: 10.1039/C9GC00396G
2
AuPd alloy is Au66Pd34 with a TOF of 200 mol mol-1metal h , which
-1
-1
-
Table 1. C-Au66Pd34 catalyzed reductive amination of EL to form pyrrolidone derivativesa
is about ten times higher than that of C-Pd (22 mol mol metal
1
h
). While adding more Pd to Au66Pd34 slows down the reaction
kinetics, alloying extra Au with Au66Pd34 results in an even
sharper drop in AuPd activity, indicating that the right control
of metal composition of AuPd NPs is essential to achieve
optimal catalytic reductive amination of EL.
A series of amines were chosen to react with EL to test the
scope of the C-Au66Pd34 catalyzed reactions. The reaction
results are summarized in Table 1. The product yields listed in
1
the table were calculated through H NMR using mesitylene as
the internal standard, while the isolated yields are given in
1
13
parentheses ( H and C NMR spectra of purified products are
provided in the SI). From this table, we can see that the C-
Au66Pd34 catalyst is most effective in converting aliphatic amines
and EL to the corresponding pyrrolidones (Table 1, entries 1-8).
The catalysis is nearly equally effective when a hydroxyl or
methoxy group is present (Table 1, entries 9-10). However,
when cyclohexylamine was used to react with EL, the b12
pyrrolidone yield was decreased to 35% (Table 1, entry 11). As
the cyclohexyl group is aliphatic, this low yield formation of
pyrrolidone cannot be attributed to an electronic effect, rather
it is more likely caused by the steric effect of the cyclohexyl
group, preventing the ring-closure to form the pyrrolidone
a
Reaction conditions: R-NH (3 mmol), EL (3 mmol), C-Au66Pd34 (0.3 mol%), 85 ˚C,
2
h, atm H . Isolated yields are in parentheses
2
1
LA (3 mmol) was used instead of EL; product formed was same as entry 1
-acetylbutyric acid (3 mmol) was used instead of EL; product formed was 6-
methyl-1-octylpiperidin-2-one
c
4
2
reactions, both generation of ambient pressured H and
reductive amination (Figure S4). We should also note that AB
could not be mixed with EL for reductive amination as AB could
reduce EL’s ketone C=O to C-OH, lowering the C=O amination
reaction efficiency.
The enhanced activity of Au66Pd34 over elemental Au, Pd,
and other AuPd NPs may be attributed to the alloy interaction
between Au and Pd, in which Pd becomes “electron-deficient”,
(Scheme 1). When phenethylamine, benzylamine, or aniline
reacted with EL, the pyrrolidone yield was decreased
dramatically from 92%, to 55%, down to 13% (Table 1, entries
18
1
2
2-14). There is a clear trend that the closer the -NH group is
to the benzene-ring, the lower the product yield. In these cases,
electronic effect must dominate the reaction process, along
with contributions from steric effect. In the first step of AuPd-
19
promoting reductive reactions. This was supported by X-ray
2
catalyzed reductive amination of EL, -NH undergoes a
photoelectron spectroscopy (XPS) analyses (Figure S5). When
compared to C-Au, C-Au66Pd34 exhibits a negative binding
energy shift in both Au 4f5/2 (-0.3 eV) and Au 4f7/2 peaks (-0.2
eV). This negative shift is caused by electron build-up on Au as
Au is more electronegative than Pd. The C-Au66Pd34 also has a
small positive binding energy shift (+0.1 eV) in the Pd 3d3/2 peak,
consistent with what was observed from other AuPd-based
nucleophilic addition to EL to form an imine intermediate; the
imine is hydrogenated to an amine which then acts as a
nucleophile reacting with the ester portion of the molecule to
form pyrrolidone (Scheme 1). The closer the -NH
benzene-ring, the stronger the p-π conjugation between N and
C(sp ), which disperses the electron pair from N to C(sp ),
2
group is to the
2
2
reducing R-NH’s nucleophilicity for the cyclic nucleophilic
addition and pyrrolidone ring formation. The negative effect of
20
systems. Therefore, Pd-catalysis is enhanced for this reaction
by its alloying with Au. However, when too much Au is present,
as in Au84Pd16, AuPd catalytic ability drops sharply. Therefore,
there is a structure balance in AuPd to show a proper degree of
Pd Lewis acidity and Pd exposure, and Au66Pd34 is the best
Au/Pd combination for catalyzing the reductive amination. This
differs from recent arguments about isolated and dilute Pd
the electron conjugation between N and C(sp
in a pressurized condition, in reported similar conversions.
2
) was overcome
6
,8
The C-Au66Pd34 catalysis is not limited to the reductive
amination of EL but can be extended to reductive amination of
LA as well. Under the same 1 atm H and 85 ˚C condition as in
2
the EL conversion, LA could react with octylamine to give 5-
methyl-1-octylpyrrolidin-2-one in 91% yield (Table 1, entry 15).
The catalysis could be further extended to reductive amination
of 4-acetylbutryic acid to form a six-membered N-heterocycle,
piperidine derivative, in 89% yield (Table 1, entry 16).
being the most active AuPd catalysts for both hydrosilylation
16,21
and selective catalytic oxidations.
To understand the
importance of Au in the AuPd catalytic reaction, we synthesized
Cu52Pd48 and
Piperidines
pharmaceuticals for cancer treatments and natural products.
We should note that the H we used for the current reductive
are
important
scaffolds
in
designing
1
7
2
amination reaction could be obtained directly from C-Au66Pd34
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Scheme 1. Reductive amination of EL to pyrrolidone through an
imine intermediate.
Conflicts of interest
There are no conflicts to declare.
View Article Online
DOI: 10.1039/C9GC00396G
Ag48Pd52 NPs of comparable sizes and morphologies as previously
1
0,13
described,
and octylamine under the same 1 atm H
6 h (Table S2). We can see that the pyrrolidone yield obtained from
the Ag48Pd52 NP catalysis (75%) is higher than that from Cu52Pd48
37%), but lower than that from either Au66Pd34 (99%) or Au40Pd60
and tested their catalysis for the reaction between EL Acknowledgement
2
and 85 °C condition, but for
The work was supported in part by the U.S. Army Research
Laboratory and the U.S. Army Research Office under grant W911NF-
1
1
5-1-0147, and by Strem Chemicals. M.M. is supported by the
(
National Science Foundation Graduate Research Fellowship, under
Grant No. 1644760. The authors greatly thank Anthony McCormick
for his time and assistance with the XPS measurements.
catalysis (91%). CuPd is even a poorer catalyst than Pd. These provide
strong evidence that the Lewis acidity of Pd in the Pd alloy NPs helps
to improve Pd catalysis for the reductive amination.
Another important feature of the Au66Pd34 catalyst is its
stability in the reductive amination condition. When used to
catalyze the reaction of EL and octylamine, the C-Au66Pd34
catalyst could easily be recycled 10 times without obvious
change in the NP’s morphology, composition, loading amount
on support, and catalysis (Figure S6). C-Au66Pd34 could also be
used for the same reaction after 1 year exposure to air (Table
S1). To further demonstrate that the observed catalysis is
originated from the alloy NPs, not from the leached Pd in the
reaction solution, we performed the reductive amination of EL
with octylamine first in the presence of the AuPd catalyst, then
Notes and references
1
(a) P. Gallezot, Chemical Society Reviews. 2012, 41, 1538-1558. (b) F. Jin
and H. Enomoto, Energy Environ. Sci., 2011, 4, 382-397. (c) B. Girisuta,
L. P. B. M. Janssen and H. J. Heeres, Ind. Eng. Chem. Res., 2007, 46,
1696–1708.
2
(a) T. A. Bender, J. A. Dabrowski and M. R. Gagné, Nat. Rev. Chem., 2018,
2
1
, 35–46. (b) A. Corma Canos, S. Iborra and A. Velty, Chem. Rev., 2007,
07, 2411-2502. (c) D. J. Braden, C. A. Henao, J. Heltzel, C. C. Maravelias
and J. A. Dumesic, Green Chem., 2011, 13, 1755-1765. (c) C. Wang, L.
Wang, J. Zhang, H. Wang, J. P. Lewis and F. S. Xiao, J. Am. Chem. Soc.,
2
016, 138, 7880–7883. (d) R. Alamillo, M. Tucker, M. Chia, Y. Pagán-
Torres and J. Dumesic, Green Chem., 2012, 14, 1413–1419. (d) 1 F. M.
A. Geilen, B. Engendahl, A. Harwardt, W. Marquardt, J. Klankermayer
and W. Leitner, Angew. Chem. Int. Ed., 2010, 49, 5510–5514.
3
h later, we filtered off the catalyst from the reaction mixture
and continued to monitor the solution phase reaction for
another 12 h. We found that there was no additional
pyrrolidone formation in this extra 12 h reaction period (Figure
S7), confirming that our C-Au66Pd34 is active and stable for the
reductive amination reaction and the observed catalysis is
solely from the alloy NPs, not from the leached Pd.
3
4
(a) E.L. Manzer, U.S. Patent 6743819B1, Production of 5-Methyl-N-Aryl-
2
-Pyrrolidone and 5-Methyl-N-Cycloalkyl-2-Pyrrolidone by Reductive
Amination of Levulinic Acid with Aryl Amines, 2004. (b) R. Jiang, H. Y. Xu,
X. P. Xu, X. Q. Chu and S. J. Ji, Org. Biomol. Chem., 2011, 9, 5659-5669.
(a) J. D. Vidal, M. J. Climent, P. Concepcion, A. Corma, S. Iborra and M. J.
Sabater, ACS Catal., 2015, 5, 5812–5821. (b) S. M. A. H. Siddiki, A. S.
Touchy, A. Bhosale, T. Toyao, Y. Mahara, J. Ohyama, A. Satsuma and K.
I. Shimizu, ChemCatChem, 2018, 10, 789–795. (c) A. S. Touchy, S. M. A.
Hakim Siddiki, K. Kon and K. I. Shimizu, ACS Catal., 2014, 4, 3045–3050.
Conclusions
(d) Y. B. Huang, J. J. Dai, X. J. Deng, Y. C. Qu, Q. X. Guo and Y. Fu,
In summary, we have reported our studies on AuPd NP cata-
lyzed reductive amination of EL to pyrrolidones. We prepared
ChemSusChem, 2011, 4, 1578–1581. (e) T. Zhang, Y. Ge, X. Wang, J.
Chen, X. Huang and Y. Liao, ACS Omega, 2017, 2, 3228–3240. (f) J. D.
Vidal, M. J. Climent, A. Corma, D. P. Concepcion and S. Iborra,
ChemSusChem, 2017, 10, 119–128. (g) C. Ortiz-Cervantes, M. Flores-
Alamo and J. J. García, Tetrahedron Lett., 2016, 57, 766–771.
C. Xie, J. Song, H. Wu, Y. Hu, H. Liu, Z. Zhang, P. Zhang, B. Chen, B. Han,
J. Am. Chem. Soc., 2019, Article ASAP, DOI: 10.1021/jacs.8b13024.
J. Zhang, B. Xie, L. Wang, X. Yi, C. Wang, G. Wang, Z. Dai, A. Zheng and F.
S. Xiao, ChemCatChem, 2017, 9, 2661–2667.
3
.8 nm AuPd NPs on simple carbon support with composition
control and found that their catalysis for the reductive
amination reaction was Au/Pd composition dependent. The
Au66Pd34 alloy NPs showed the highest activity in catalyzing the
5
6
7
reactions between primary amines and EL under 1 atm H
2
at 85
˚
C, forming pyrrolidones with the reaction turnover frequency
(a) Y. Wei, C. Wang, X. Jiang, D. Xue, Z. T. Liu and J. Xiao, Green Chem.,
2014, 16, 1093-1096. (b) T. Ma, H. Y. Zhang, G. Yin, J. Zhao and Y. Zhang,
J. Flow Chem., 2018, 8, 35-43.
-1
-1
(TOF) reaching as high as 200 mol mol metal h and isolated
product yields > 90%. The AuPd catalysis was further extended
to reductive amination of LA/4-acetylbutyric acid to
pyrrolidone/piperidine derivatives. This, combining with the
reductive amination of EL, provides a general green chemistry
approach with efficient and reusable catalysis to convert
EL/LA/4-acetylbutyric acid selectively without solvent to
8
9
(a) G. Chieffi, M. Braun and D. Esposito, ChemSusChem, 2015, 8, 3590–
3
594. (b) X. L. Du, L. He, S. Zhao, Y. M. Liu, Y. Cao, H. Y. He and K. N. Fan,
Angew. Chemie - Int. Ed., 2011, 50, 7815–7819.
(a) C. Yu, X. Guo, Z. Xi, M. Muzzio, Z. Yin, B. Shen, J. Li, C. T. Seto and S.
Sun, J. Am. Chem. Soc., 2017, 139, 5712–5715. (b) C. Yu, X. Guo, M. Shen,
B. Shen, M. Muzzio, Z. Yin, Q. Li, Z. Xi, J. Li, C. T. Seto and S. Sun, Angew.
Chemie - Int. Ed., 2018, 57, 451–455.
C. Yu, X. Guo, B. Shen, Z. Xi, Q. Li, Z. Yin, H. Liu, M. Muzzio, M. Shen, J. Li,
C. T. Seto and S. Sun, J. Mater. Chem. A, 2018, 6, 23766–23772.
2
pyrrolidones/piperidines under ambient H pressure generated
1
0
by a solid H source. These pyrrolidones/piperidines are
2
important scaffolds in designing polymers, natural products and 11 (a) T. Yuan, H. Y. Chen, X. Ma, J. J. Feng, P. X. Yuan and A. J. Wang, J.
pharmaceuticals for functional materials and biomedical
applications. Taking advantage of the interactions of metals in
alloy nanoparticles may provide a promising new green
chemistry approach to biomass conversions.
Colloid Interface Sci., 2018, 513, 324–330. (b) L. X. Chen, L. Y. Jiang, A. J.
Wang, Q. Y. Chen and J. J. Feng, Electrochim. Acta, 2016, 190, 872–878.
(c) X. Chen, X. Chen, Z. Cai and M. Oyama, J. Mater. Chem. A, 2014, 2,
5
668–5674. (d) D. I. Enache, J. K. Edwards, P. Landon, B. Solsona-Espriu,
A. F. Carley, A. A. Herzing, M. Watanabe, C. J. Kiely, D. W. Knight and G.
J. Hutchings, Science, 2006, 311, 362–365.
1
2
O. Metin, X. Sun and S. Sun, Nanoscale, 2013, 5, 910–912.
4
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
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Page 5 of 6
Please Gd roe en no tC ha ed mj u iss tt r my argins
Journal Name
COMMUNICATION
1
3
(a) Z. Xi, J. Li, D. Su, M. Muzzio, C. Yu, Q. Li and S. Sun, J. Am. Chem. Soc.,
017, 139, 15191-15196. (b) S. Peng, Y. Lee, C. Wang, H. Yin, S. Dai and
S. Sun, Nano Res., 2008, 1, 229–234.
View Article Online
DOI: 10.1039/C9GC00396G
2
1
4
(a) S. J. Li, Y. Ping, J. M. Yan, H. L. Wang, M. Wu and Q. Jiang, J. Mater.
Chem. A, 2015, 3, 14535-14538.. (b) Z. L. Wang, J. M. Yan, Y. F. Zhang, Y.
Ping, H. L. Wang and Q. Jiang, Nanoscale, 2014, 6, 3073-3077.
1
1
1
5
6
7
S. Zhang, Ö. Metin, D. Su and S. Sun, Angew. Chemie - Int. Ed., 2013, 52,
3
681-3684.
C. J. Wrasman, A. Boubnov, A. R. Riscoe, A. S. Hoffman, S. R. Bare and
M. Cargnello, J. Am. Chem. Soc., 2018, 140, 12930-12939.
(a) P. Goel, O. Alam, M. Naim, M. Alam, Eur. J. Med. Chem. 2018, 157,
5
80–502. (b) B. D. Narhe, A. C. Breman, J. Padwal, D. A. L. Vandenput, J.
M. Scheidt, J. C. J. Benningshof, G. A. van der Marel, H. S. Overkleeft, M.
van der Stelt and D. V. Filippov, Bioorganic Med. Chem., 2017, 25, 5160-
5
170.
L. Shi, Y. Liu, Q. Liu, B. Wei and G. Zhang, Green Chem., 2012, 14, 1372–
375.
1
1
8
9
1
(a) G. J. Hutchings, Chem. Commun., 2008, 1148–1164. (b) M. Sankar, Q.
He, S. Dawson, E. Nowicka, L. Lu, P. C. A. Bruijnincx, A. M. Beale, C. J.
Kiely and B. M. Weckhuysen, Catal. Sci. Technol., 2016, 6, 5473-5482.
(a) K. Qian and W. Huang, Catalysis Today, 2011, 1, 320–324. (b) W. Luo,
M. Sankar, A. M. Beale, Q. He, C. J. Kiely, P. C. A. Bruijnincx and B. M.
Weckhuysen, Nat. Commun., 2015, 6, 6540.
2
2
0
1
H. Miura, K. Endo, R. Ogawa and T. Shishido, ACS Catal., 2017, 7, 1543–
1
553.
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Green Chemistry
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DOI: 10.1039/C9GC00396G
Efficient and reusable AuPd alloy nanocatalysts facilitate the conversion of biomass derivatives to useful
pyrrolidones under the mildest reported conditions.