Dramatic effect of the gelling cation on the catalytic performances of alginate-supported palladium nanoparticles for the Suzuki-Miyaura reaction

Article abstract of DOI:10.1021/cm3003595

This work describes the preparation and characterization of a library of alginate-supported palladium nanoparticles together with their catalytic capabilities to promote the Suzuki-Miyaura reaction. Using the chelating properties of the carboxylate functions of the alginate matrix a series of Ca, Ba, Mn, Zn, Ni, Ce, Cu, and Co alginate gels were first prepared and then reacted with Pd²⁺ salts. Partial exchange of metal cations followed by Pd reduction into palladium nanoparticles and supercritical CO₂ drying generated a panel of bimetallic alginate aerogels. Physical characterizations of these materials showed a significant influence of both the gelling metal nature and the Pd loading on surface areas and nanoparticles size. A comparative study of the catalytic performances of these heterogeneous catalytic systems is then reported for the Suzuki-Miyaura reaction. This study highlighted the superior performances of palladium nanoparticles supported on copper-alginate aerogels. This heterogeneous catalyst showed high catalytic activities as illustrated by a TOF value of 10 s^-1 and a TON value close to 10⁶. The robustness of the catalyst allowed several reuses with no significant loss of activity or metal leaching.

Full text of DOI:10.1021/cm3003595

Article
pubs.acs.org/cm
Dramatic Effect of the Gelling Cation on the Catalytic Performances
of Alginate-Supported Palladium Nanoparticles for the Suzuki−
Miyaura Reaction
Melanie Chtchigrovsky,† Yi Lin,‡ Kahina Ouchaou,† Manon Chaumontet,† Mike Robitzer,‡
́
Franco
̧
ise Quignard,‡,* and Frederic Taran†,*
́
́
†CEA, iBiTecS, Service de Chimie Bioorganique et de Marquage, Gif sur Yvette, F-91191, France
‡Institut Charles Gerhardt-Montpellier, Mater
́
iaux Avances pour la Catalyse et la Sante, UMR5253 CNRS-ENSCM-UM2-UM1, 8 rue
́
́
de l’Ecole Normale, 34296 Montpellier, France
S
* Supporting Information
ABSTRACT: This work describes the preparation and characterization
of a library of alginate-supported palladium nanoparticles together with
their catalytic capabilities to promote the Suzuki−Miyaura reaction.
Using the chelating properties of the carboxylate functions of the alginate
matrix a series of Ca, Ba, Mn, Zn, Ni, Ce, Cu, and Co alginate gels were
first prepared and then reacted with Pd2+ salts. Partial exchange of metal
cations followed by Pd reduction into palladium nanoparticles and
supercritical CO2 drying generated a panel of bimetallic alginate aerogels.
Physical characterizations of these materials showed a significant
influence of both the gelling metal nature and the Pd loading on surface areas and nanoparticles size. A comparative study of
the catalytic performances of these heterogeneous catalytic systems is then reported for the Suzuki−Miyaura reaction. This study
highlighted the superior performances of palladium nanoparticles supported on copper-alginate aerogels. This heterogeneous
catalyst showed high catalytic activities as illustrated by a TOF value of 10 s−1 and a TON value close to 106. The robustness of
the catalyst allowed several reuses with no significant loss of activity or metal leaching.
KEYWORDS: heterogeneous catalysis, polysaccharides, cross-coupling, palladium, boronic acids
particularly interesting anionic biopolymer to create high
performance heterogeneous Pd-based catalysts. Alginate,
commonly isolated from brown algae, is a linear unbranched
polysaccharide composed of (1−4)-linked β-D-mannuronate
(M) and α-L-guluronate (G) monomers that are organized in
blocks along the polymeric chains. A particular advantageous
characteristic of alginate solutions is their capacity to form
hydrogels when exposed to metal cations.15 The rheology of
calcium cross-linked alginate gels has been extensively studied,
and their structures have been described by the so-called egg-
box model in which each calcium atom is coordinated to the
carboxylates and hydroxyl groups of four G monomers from
two adjacent chains of alginate.16 The metal loading capacity of
alginate is therefore quite high; it has been estimated at around
5.6 mmol·g−1. Recent investigations conducted by our group17
proved that simple incubation of such alginate/Ca2+ gels in
solutions containing Pd2+ salts allows partial metal exchange
through the gel structure, thus generating a heterogeneous
bimetallic alginate/Ca2+/Pd2+ gel. The supported Pd2+ can then
easily be reduced by simple treatment with EtOH to generate
PdNPs (Figure 1). Since this alginate/Ca2+/PdNPs heteroge-
INTRODUCTION
■
The Suzuki−Miyaura coupling reaction has gained wide
acceptance in the synthetic community as one of the most
powerful tools in C−C bond formation. Many laboratories have
developed highly active homogeneous catalyst systems that
process challenging combinations of aryl halides and boronic
acids1 and display very high TON and TOF values.2 Because
sustainable development involves the utilization of recyclable
catalysts, the search for greener palladium-based catalysts to
replace existing homogeneous ones is an important goal. In this
regard, supported palladium nanoparticles (PdNPs) have
attracted much attention as a major advance in this field.3
Numerous supports including carbon structures,4 polymers,5
dendrimers,6 micelles,7 aluminum hydroxide,8 polyoxometales,9
gold nanocores,10 resins,11 biomolecules,12 and various
inorganic materials13 have been successfully employed. As
most of the mass of these systems is constituted by the support,
the development of heterogeneous catalysts using renewable,
biodegradable, and inexpensive supports is one important issue.
Recent work in our groups proved that polysaccharides are
promising biopolymer supports for heterogeneous catalysis.14
Polysaccharides have indeed unlimited availability as renewable
agro-resources, are biodegradable, and present interesting
rheological properties that may be successfully exploited as
support for catalysts. Among those polysaccharides, alginate is a
Received: February 1, 2012
Revised: March 23, 2012
Published: March 23, 2012
© 2012 American Chemical Society
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prevent any thermal decomposition of organic polymer or any
undesirable evolution of metallic species.
Surface areas were evaluated by the BET method. The local
composition on gel cross sections was analyzed by an energy-
dispersive X-ray (EDX) microprobe on a Quanta 200 F from FEI.
General Procedure for the Alginate/Mn+/PdNP Preparation. The
procedure involves three main steps: (i) the formation of alginate/Mn+
gels, (ii) partial exchange of Mn+ by Pd2+, and (iii) reduction of Pd2+ to
generate PdNP (Figure 2).
Figure 1. Chemical structure of alginate and schematic presentation of
alginate/Ca2+/PdNP preparation.
neous catalyst was found to display interesting features for the
Suzuki−Miyaura reaction,17 we were interested in extending
our procedure to the preparation of PdNPs supported on
numerous alginate/Mn+ gels to look at their catalytic activities.
In this contribution we show how our procedure is general
and might be applied to many gelling metals Mn+ allowing the
straightforward preparation of a panel of alginate/Mn+/PdNPs
gels. The resulting bimetallic hybrid catalysts are of prime
interest since they combine the textural properties of alginate,
the high catalytic activity of palladium nanoparticles and the
presence of a second metal species that might influence the
catalytic performances. After systematic evaluation of the
catalytic properties of these heterogeneous catalysts for the
Suzuki reaction, a dramatic influence of the gelling metal Mn+
was highlighted.
Figure 2. Experimental procedure used to make alginate/Mn+/PdNP.
Picture of alginate/Cu2+/PdNP beads.
A 2% (w/w) solution of alginate is added drop by drop, at room
temperature, to a Mn+Cln− aqueous solution (0.24 M) with stirring,
using a syringe with a 0.8 mm diameter needle. Gel microspheres are
cured in the Mn+ solution for 3 h, separated from the solution, and
washed with distilled water. The spheres are then immersed for 19 h in
a Na2PdCl4 aqueous solution containing the exact amount of Pd to
ensure the exchange of 3, 6, or 9% of Mn+ ions in the alginate gel. The
beads are washed with distilled water. Hydrogel beads are then
dehydrated in a series of successive ethanol−water baths of increasing
alcohol concentration (10, 30, 50, 70, 90, and 100%) for 15 min each.
Reduction of palladium occurs during the dehydration step with
ethanol. The alcogel beads are then dried under supercritical CO2
conditions (slightly beyond 73 bar and 31 °C) in a Polaron 3100
apparatus, thus yielding aerogel beads. The catalyst is used as obtained
from supercritical drying without any further reduction step.
EXPERIMENTAL SECTION
■
Chemicals and Instruments. Chemicals were purchased from
Aldrich. Organic solvents (Aldrich) were used without further
purification. Purifications of reaction products were carried out by
flash chromatography using Merck silica gel (40−63 μm). Melting
General Procedure for the Alginate/Cu2+/PdNP-Catalyzed Suzuki
Reaction. No precautions were taken to exclude oxygen. One bead of
alginate/Cu2+/PdNP (0.2 mg, 18 nmol, 0.01% mol), boronic acid
(0.18 mmol, 1 equiv), K2CO3 (0.54 mmol, 3 equiv) and aryl bromide
(0.18 mmol, 1 equiv.) in 2 mL of EtOH was heated at 70 °C for 14 h
in a closed vial. The mixture was separated from the catalyst, and
solvent was removed in vacuo to afford after purification on silica gel
pure biaryl products.
̈
points (Mp) were obtained on a BUCHI Melting Point B-540.
Infrared spectra (IR) were obtained on a Perkin-Elmer system 2000
FTIR spectrophotometer and are reported as wavelength numbers
(cm−1). Infrared spectra were collected by preparing a KBr pellet
1
containing the title compound. H NMR (400 MHz) and 13C NMR
(100 MHz) were measured on a Bruker Avance 400 MHz
spectrometer. Chemical shifts are reported in parts per million
(ppm, δ) downfield from residual solvents peaks, and coupling
constants are reported as Hertz (Hz). Splitting patterns are designated
as singlet (s), doublet (d), triplet (t), and so forth. Splitting patterns
that could not be interpreted or easily visualized are designated as
multiplet (m). Electrospray mass spectra were obtained using an ESI/
TOF Mariner Mass Spectrometer. Unless otherwise noted, all other
commercially available reagents and solvents were used without further
purification.
Alginate (viscosity 3500 cps for a 2 wt % aqueous solution at 20 °C,
mannuronic/guluronic ratio 1.82 by spectroscopic evaluation) was
purchased from Aldrich.
Transmission electron microscopy (TEM) was performed with
JEOL 1200 EXII TEM, operated at 120 kV. Nitrogen adsorption/
desorption isotherms were recorded in a Micromeritics ASAP 2010
apparatus at 77 K after outgassing the sample at 323 K under vacuum
until a stable 3 × 10−5 Torr pressure was obtained without pumping.
Sample outgassing was performed at 323 K for all the catalysts to
RESULTS AND DISCUSSION
■
Catalysts Preparation and Characterization. A library
of 24 alginate supported Mn+/PdNP hybrid catalysts was
prepared according to the above-described procedure by using
eight different gelling metals and three Mn+/Pd ratios (97/03,
94/06, and 91/09). Acidic alginate gels (free of gelling metal)
and alginate/Mn+ gels (free of Pd) were also prepared for
comparison. Thus, a total of 36 alginate aerogels were prepared
and characterized. First, the metals content of the different
materials was determined by ICP (plasma with inductive
coupling). The obtained analytical data (Figure 3A and
Supporting Information) indicated that the Mn+/Pd2+ exchange
is quantitative in a solution containing the exact number of Pd
ions needed for a desired Pd loading and is independent of the
nature of the gelling cation.
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external surface to the core of the microspheres (EDX analysis),
and no metal agglomeration was observed.
Catalytic Properties of the Alginate Materials. The 36
hybrid catalysts were first screened for their ability to catalyze
the Suzuki coupling reaction of reactants 1a and 2a in a panel
of reaction conditions. The fluorescence properties of the
coupling product 3a allowed a rapid screening of the influence
of several reaction parameters, including solvents and bases, on
the activity and recyclability of the catalyst library. A total of
1296 reactions (catalysts tested in six solvents and six bases)
were run and screened in microtiter plates. Each tested catalyst
was recovered after the reaction and tested again in three
additional catalytic cycles to look at its recyclability.
Representative results obtained in DMF in the presence of
K2CO3 are indicated in Figure 5.
Figure 3. (A) Correlation between expected and obtained Pd/Mn+
ratios. (B−D) Surface areas and NP size distribution of alginate/Mn+/
PdNP containing 3, 6, and 9% of Pd compared with Mn+.
The surface areas and the size of PdNPs of each alginate
aerogel were then determined. Globally, all microspheres dried
in supercritical CO2 provide a porous material with large
surface areas (over 200 m2·g−1, Figure 3B−D) that are entirely
accessible due to an open pore structure of the network (pore
size > 10 nm according to SEM analysis). A strong influence of
the gelling metal nature on the surface areas of alginate/Mn+/
PdNP aerogels has been observed. Although Mn2+, Ni2+, Zn2+,
and Co2+ did not induce significant change, the use Ca2+, Ba2+,
Ce3+, and Cu2+ increased the surface areas when compared with
the solids obtained without gelling metal Mn+. This effect is
more particularly observed in the case of Cu2+ which doubles
the surface area of the aerogel beads.
Extensive TEM analysis of each alginate bead indicated that
the size and dispersion of PdNPs depends both on the nature
of Mn+ and on the Pd/Mn+ ratio. The optimum Pd/Mn+ ratio
was found to be 97/03 which allows the formation of
monodispersed PdNPs; higher ratios generated a larger range
of sizes and some formation of nanoparticles aggregation. At
this Pd/Mn+ ratio particle size was close to 7 2 nm whatever
the gelling metal Mn+, except Cu2+ for which a particular narrow
size distribution was obtained. Physical characterizations of this
solid showed palladium nanoparticles of 3 1 nm size (Figure
4) dispersed in a high surface area of 671 m2·g−1 (Figure 3B).
Scanning electron microscopy (SEM) showed an open network
of fibrils and a high dispersion of palladium within the network:
the same range of metal concentration was found from the
Figure 5. Screening results. Experiments were carried out at 2 mM
substrates, 6 mM K2CO3, and 0.1% mol of Pd in DMF at 50 °C for 1
h.
The screening results first indicated that the percentage of Pd
compared with the gelling metal Mn+ strongly influences the
recyclability of the heterogeneous catalysts: in many cases
percentages higher than 3% resulted in loss of catalytic
efficiencies even after the first cycle. Deactivation may be due
to palladium nanoparticles aggregation and/or textural
instability depending on the solvent. In this respect, the
alginate/Cu2+/PdNP catalysts were the most recyclable since
they displayed intact catalytic efficiency (99% yield of 3a) after
the fourth cycle. This result suggests a better stability of copper
cross-linked alginate gels over those obtained with other gelling
metals.
The gelling metal also has a strong effect on the catalytic
properties of the alginate aerogels, in terms of both activity and
recyclability. With the exception of Co2+, all other gelling
metals induced a positive effect on the catalytic efficiencies of
the alginate supported catalysts. Kinetic experiments conducted
with 0.01% mol of Pd showed a particular benefit in using Cu2+
as gelling metal (Figure 6).
The high value of alginate/Cu2+/PdNP (97/03) in regard to
its efficiency and practicability was further confirmed by a series
of experiments conducted at the millimole scale on the target
reaction. Only 10 ppm of Pd (10 beads, 2 mg) in EtOH at 70
°C was required for complete conversion of 5.6 g of reactants
1a and 2a to the biaryl product 3a in only 3 h (Table 1, entry
7).
Control experiments conducted with 100 ppm of the
alginate/Cu2+/PdNP (97/03) catalyst are in agreement with a
heterogeneous catalysis mode. First, the recyclability of the
catalyst has been confirmed on six cycles of reaction (Figure
7A). Quantitative ICP analysis of the product from each cycle
Figure 4. (A) SEM image of alginate/Cu2+/PdNP (97/03). (B) NP
size distribution and TEM image of alginate/Cu2+/PdNP (97/03).
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Scheme 1. Suzuki Coupling of Aryl Bromides with Aryl
a
Boronic Acids
Figure 6. Influence of Mn+ on the formation of 3a from 1a and 2a.
Experiments were carried out at 2 mM substrate, 6 mM K2CO3, and
0.01% mol of Pd using alginate/Mn+/PdNP (97/03) in DMF at 100
°C for 1 h.
a
Table 1. Comparison of the Catalytic Efficiencies (TOF
values) for the Alginate/Mn+/PdNP (97/03) Catalysts
Highlighted by Screening
catalyst
time
(h)
yield of
TOF
(h−1
a
b
Reactions were carried out at 0.1 M for substrates 1 and 2 and 0.3 M
entry
Mn+
(% mol)
3a
)
TON
K2CO3.
1
2
3
4
5
6
7
8
No
0.01
2
2
39%
73%
75%
90%
91%
99%
99%
91%
1950
3650
3900
7300
7500
9000
9100
Mn2+
Ca2+
Ba2+
Ce3+
Cu2+
Cu2+
Cu2+
0.01
entry 8), may be first explained by the atypical physical
properties of the material due to Cu2+ alginate chelation. The
small size of Pd nanoparticles (3 1 nm), their high dispersion
within the polysaccharide network, and the high surface area of
the material (671 m2·g−1) may explain the superior activity of
this catalyst over those obtained with other gelling metals.
However, one cannot exclude a synergic Cu−Pd effect on the
catalysis as previously observed for mixed Pd−Cu nanocluster
colloids.18
0.01
1
7500
0.01
0.75
0.75
0.33
3
12000
12130
30000
33000
35000
0.01
0.01
0.001
0.0001
26
910000
a
Reactions were carried out at 0.1 M for substrates 1a and 2a, 0.3 M
K2CO3 in EtOH at 70 °C. Isolated yields.
b
Boronic acids are well-known to undergo boronate formation
when heated with sugar backbones.19 We therefore wondered
whether such a phenomenon might happen between the
boronic reactant and the polysaccharide support and whether it
can impact the catalytic reaction. For that purpose we reacted
the blue-colored azulene-2-boronic acid20 with the alginate/
Cu2+/PdNP catalyst and found that only 5% of the diols
present in the alginate backbone are available for boronate
formation. During the reaction the alginate microspheres turn
deep blue; no discoloration was observed after several washing
with DMF. Upon addition of aryl bromide 1a, this alginate-
supported azulene-2-boronate undergoes complete and rapid
conversion to the corresponding Suzuki product 3q (Figure 8).
Figure 7. (A) Recyclability of the alginate/Cu2+/PdNP (97/03)
catalyst. (B) Control experiment. Kinetics were carried out without
removal (red squares) and with removal of the catalyst after 15 min
(green ciricles) as indicated by the arrow. Reactions and kinetics were
conducted using 0.1 M of substrates 1a and 2a and 0.3 M K2CO3 in
EtOH at 70 °C for 90 min. The catalyst was used at 100 ppm of Pd.
revealed undetectable leaching of palladium and copper. TEM
micrographs recorded before and after the reactions showed no
evidence of palladium precipitates or nanoparticle aggregation.
Second, removal of the catalyst during the reaction stopped the
evolution of the coupling reaction (Figure 7B).
To look at the scope of the alginate/Cu2+/PdNP (97/03)
catalysis, a series of reactions were conducted with 100 ppm of
the catalyst. As shown in Scheme 1, good yields were obtained
even with hindered and basic nitrogen-containing starting
reactants.
Figure 8. Reaction of azulene-2-boronic acid with alginate/Cu2+/
PdNP (97/03) catalyst. The structure of the boronate−alginate adduct
is hypothetical.
The high catalytic properties of the alginate/Cu2+/PdNP
catalyst, illustrated by high TOF and TON values (Table 1,
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(2) See for example: (a) Arvela, R. K.; Leadbeater, N. E.; Sangi, M. S.;
Williams, V. A.; Granados, P.; Singer, R. D. J. Org. Chem. 2005, 70,
161−168. (b) Lasri, J.; Guedes da Silva, M. F. C.; Kopylovich, M. N.;
Mukhopadhyay, S.; Charmier, M. A. J.; Pombeiro, A. J. L. Dalton
Trans. 2009, 2210−2216. (c) Okumura, K.; Matsui, H.; Tomiyama, T.;
Sanada, T.; Honma, T.; Hirayam, S.; Niwa, M. ChemPhysChem 2009,
10, 3265−3272.
Although this control experiment does not provide
unambiguous mechanistic rationale, it proves that boronic
substrates may react with the sugar backbone of the catalyst but
this phenomenon is, at least, not prejudicial to the catalysis.
CONCLUSION
■
(3) (a) Djakovitch, L.; Kohler, K.; De Vries, J. G. In Nanoparticles and
In conclusion, we report an easily recoverable hybrid catalyst
which combines the catalytic power of palladium nanoparticles
with the architecture of a metal/alginate network that displays
high catalytic efficiency for the Suzuki reaction. One of the
main advantages of the reported heterogeneous catalysts is the
simplicity and inexpensiveness of their preparation. The
procedure is easily scaled-up to multigram catalyst preparation
with a cost depending almost exclusively on the price of the
metal. Besides the fact that the procedure is trivial to run, an
added bonus is that it is easy to manage the Mn+/Pd ratio
simply by changing the concentration of the Pd2+ solution used
in the incubation step. Recent investigation in our laboratories
indicated that the described procedure is easily extended to the
preparation of alginate-supported gold and platinum nano-
particles, emphasizing the great potential of this technique.
̈
Catalysis; Astruc, D., Ed.; Wiley-VCH: Weinheim, 2008. (b) Balanta,
A.; Godard, C.; Claver, C. Chem. Soc. Rev. 2011, 40, 4973−4985.
(c) Yin, L.; Liebscher, J. Chem. Rev. 2007, 107, 133−173. (d) Yuan, B.;
Pan, Y.; Li, Y.; Yin, B.; Jiang, H. Angew. Chem., Int. Ed. 2010, 49,
5916−5920.
(4) (a) Scheuermann, G. M.; Rumi, L.; Steurer, P.; Bannwarth, W.;
Mulhaupt, R. J. Am. Chem. Soc. 2009, 131, 8262−8270. (b) Itoha, T.;
̈
Danjob, H.; Sasakia, W.; Uritaa, K.; Bekyarovac, E.; Araia, M.;
Imamotoa, T.; Yudasakad, M.; Iijimad, S.; Kanoha, H.; Kanekoa, K.
Carbon 2008, 46, 172−175. (c) Yoon, H.; Ko, S.; Jang, J. Chem.
Commun. 2007, 1468−1470. (d) Mahouche Chergui, S.; Ledebt, A.;
Mammeri, F.; Herbst, F.; Carbonnier, B.; Ben Romdhane, H.;
Delamar, M.; Chehimi, M. M. Langmuir 2010, 26, 16115−16121.
(e) Guerra, J.; Herrero, M. A. Nanoscale 2010, 2, 1390−1400.
(f) Siamaki, A. R.; Khder, A. R. S.; Abdelsayed, V.; El-Shall, M. S.;
Gupton, B. F. J. Catal. 2011, 279, 1−11.
(5) (a) Ornelas, C.; Diallo, A. K.; Ruiz, J.; Astruc, D. Adv. Synth.
Catal. 2009, 351, 2147−2154. (b) Li, Y.; Hong, X. M.; Collard, D. M.;
El-Sayed, M. A. Org. Lett. 2000, 2, 2385−2388. (c) Zhang, P.; Weng,
Z.; Guo, J.; Wang, C. Chem. Mater. 2011, 23, 5243−5249. (d) Bhunia,
M. K.; Das, S. K.; Pachfule, P.; Banerjee, R.; Bhaumik, A. Dalton Trans.
2012, 41, 1304−1311. (e) Jin, M.; Zhang, H.; Xie, Z.; Xia, Y. Angew.
Chem., Int. Ed. 2011, 50, 7850−7854. (f) de Luna Martins, D.; Alvarez,
H. M.; Aguiar, L. C. S. Tetrahedron Lett. 2010, 51, 6814−6817.
(g) Ohtaka, A.; Teratani, T.; Fujii, R.; Ikeshita, K.; Kawashima, T.;
Tatsumi, K.; Shimomura, O.; Nomura, R. J. Org. Chem. 2011, 76,
4052−4060. (h) Metin, O.; Durap, F.; Aydemir, M.; Zkar, S. O. J. Mol.
Catal. A: Chem. 2011, 337, 39−44. (i) Biffis, A.; Sperotto, E. Langmuir
2003, 19, 9548−9550. (j) Mejías, N.; Pleixats, R.; Shafir, A.; Medio-
ASSOCIATED CONTENT
■
S
* Supporting Information
Analytical data for products 3. Synthesis and fluorescence
properties of compound 3a. SBET and composition of all
alginate/Mn+/PdNP materials. Reaction with azulene-2-boronic
acid. Influence of solvents and bases on the catalytic properties
of alginate/Cu2+/PdNP (97/03) catalyst. This material is
available free of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
■
Corresponding Author
*E-mail, quignard@enscm.fr; fax, (+33) 467163470 (F.Q.). E-
mail, frederic.taran@cea.fr; fax, (+33) 169087991 (F.T.).
́
Simon, M.; Asensio, G. Eur. J. Org. Chem. 2010, 5090−5099.
(k) Ogasawara, S.; Kato, S. J. Am. Chem. Soc. 2010, 132, 4608−
4613. (l) Cho, J. K.; Najman, R.; Dean, T. W.; Ichihara, O.; Muller, C.;
Bradley, M. J. Am. Chem. Soc. 2006, 128, 6276−6277. (m) Houdayer,
A.; Schneider, R.; Billaud, D.; Ghanbaja, J.; Lambert. J. Appl.
Organomet. Chem. 2005, 19, 1239−1248. (n) Yu, Y.; Hu, T.; Chen,
X.; Xu, K.; Zhang, J.; Huang, J. Chem. Commun. 2011, 47, 3592−3594.
(o) Liu, G.; Hou, M.; Song, J.; Jiang, T.; Fan, H.; Zhang, Z.; Han, B.
Green Chem. 2010, 12, 65−69.
(6) Diallo, A. K.; Ornelas, C.; Salmon, L.; Aranzaes, J. R.; Astruc, D.
Angew. Chem., Int. Ed. 2007, 46, 8644−8648.
(7) (a) Okamoto, K.; Akiyama, R.; Yoshida, H.; Yoshida, T.;
Kobayashi, S. J. Am. Chem. Soc. 2005, 127, 2125−2135. (b) Okamoto,
K.; Akiyama, R.; Kobayashi, S. Org. Lett. 2004, 6, 1987−1990.
(c) Nishio, R.; Sugiura, M.; Kobayashi, S. Org. Lett. 2005, 7, 4831−
4834.
Author Contributions
The manuscript was written through contributions of all
authors. All authors have given approval to the final version of
the manuscript.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
The authors gratefully acknowledge Thomas Cacciaguerra
(ICGM) for the transmission electron microscopy. This work
was founded by the French National Research Agency (ANR,
GreenCat project).
(8) Li, X.; Yan, Y.; Chang, H.-H.; Wang, L.-C.; Zhang, Y.; Chen, W.-
W.; Li, Y.-W.; Wei, W.-L. Org. Biomol. Chem. 2012, 10, 495−497.
ABBREVIATIONS
́
(9) Corma, A.; Iborra, S.; Llabres i Xamena, F. X.; Monto, R.;
■
Calvino, J. J.; Prestipino, C. J. Phys. Chem. C 2010, 114, 8828−8836.
(10) Fang, P.-P.; Jutand, A.; Tian, Z.-Q.; Amatore, C. Angew. Chem.,
Int. Ed. 2011, 50, 12184−12188.
PdNP, palladium nanoparticles; TOF, turnover frequency;
TON, turnover number
(11) (a) Najman, R.; Cho, J. K.; Coffey, A. F.; Davies, J. W.; Bradley,
M. Chem. Commun. 2007, 5031−5033. (b) Das, P.; Sharma, D.; Shil,
A. K.; Kumari, A. Tetrahedron Lett. 2011, 52, 1176−1178.
(12) Sobjerg, L. S.; Gauthier, D.; Lindhardt, A. T.; Bunge, M.;
Finster, K.; Meyer, R. L.; Skrydstrup, T. Green Chem. 2009, 11, 2041−
2046.
(13) (a) Choi, M.; Lee, D.-H.; Na, K.; Yu, B.-W.; Ryoo, R. Angew.
Chem., Int. Ed. 2009, 48, 3673. (b) MacQuarrie, S.; Nohair, B.;
Horton, J. H.; Kaliaguine, S.; Crudden, C. M. J. Phys. Chem. C 2010,
114, 57. (c) Budroni, G.; Corma, A.; Garcia, H.; Primo, A. J. Catal.
REFERENCES
■
(1) See for example: (a) Billingsley, K. L.; Buchwald, S. L. Angew.
Chem., Int. Ed. 2008, 47, 4695−4698. (b) Billingsley, K. L.; Anderson,
K. W.; Buchwald, S. L. Angew. Chem., Int. Ed. 2006, 45, 3484−3488.
(c) Kudo, N.; Perseghini, M.; Fu, G. C. Angew. Chem., Int. Ed. 2006,
45, 1282−1284. (d) Walker, S. D.; Barder, T. E.; Martinelli, J. R.;
Buchwald, S. L. Angew. Chem., Int. Ed. 2004, 43, 1871−1876.
(e) Kirchhoff, J. H.; Dai, C.; Fu, G. C. Angew. Chem., Int. Ed. 2002,
41, 1945−1947.
1509
dx.doi.org/10.1021/cm3003595 | Chem. Mater. 2012, 24, 1505−1510

Chemistry of Materials
Article
2007, 251, 345−353. (d) Bernini, R.; Cacchi, S.; Fabrizi, G.; Forte, G.;
Petrucci, F.; Prastaro, A.; Niembro, S.; Shafir, A.; Vallribera, A. Green
Chem. 2010, 12, 150−158. (e) Han, P.; Wang, X.; Qiu, X.; Ji, X.; Gao,
L. J. Mol. Catal. A: Chem. 2007, 272, 136−141. (f) Wang, Y.; Biradar,
A. V.; Duncan, C. T.; Asefa, T. J. Mater. Chem. 2010, 20, 7834−7841.
(14) (a) Chtchigrovsky, M.; Primo, A.; Gonzalez, P.; Molvinger, K.;
Robitzer, M.; Quignard, F.; Taran, F. Angew. Chem., Int. Ed. 2009, 48,
5916−5920. (b) Peirano, F.; Vincent, T.; Quignard, F.; Robitzer, M.;
Guibal, E. J. Membr. Sci. 2009, 329, 30−45. (c) Quignard, F.; Valentin,
R.; Di Renzo, F. New J. Chem. 2008, 32, 1300−1310. (d) Valentin, R.;
Molvinger, K.; Quignard, F.; Brunel, D. New J. Chem. 2003, 27, 1690−
1692. (e) Ricci, A.; Bernardi, L.; Gioia, C.; Vierucci, S.; Robitzer, M.;
Quignard, F. Chem. Commun. 2010, 46, 6288−6290.
(15) Skjak-Braek, G.; Grasdalen, H.; Smidsod, O. Carbohydr. Polym.
1989, 10, 31−34.
(16) (a) Braccini, I.; Perez, S. Biomacromolecules 2001, 2, 1089−1096.
(b) Siew, C. K.; Williams, P. A. Biomacromolecules 2005, 6, 963−969.
(c) Li, L.; Fang, Y.; Vreeker, R.; Appelqvist, I.; Mendes, E.
Biomacromolecules 2007, 8, 464−468.
(17) Primo, A.; Liebel, M.; Quignard, F. Chem. Mater. 2009, 21,
621−627.
(18) Thathagar, M. B.; Beckers, J.; Rothenberg, G. J. Am. Chem. Soc.
2002, 124, 11858−11859.
(19) (a) Zhu, L.; Shabbir, S. H.; Gray, M.; Lynch, V. M.; Sorey, S.;
Anslyn, E. V. J. Am. Chem. Soc. 2006, 128, 1222−1232. (b) James, T.
D.; Linnane, P.; Shinkai, S. Chem. Commun. 1996, 281−288.
(c) James, T. D.; Sandanayake, K. R. A. S.; Shinkai, S. Angew.
Chem., Int. Ed. Engl. 1996, 35, 1910−1922. (d) Wang, W.; Gao, X.;
Wang, B. Curr. Org. Chem. 2002, 6, 1285−1317. (e) Striegler, S. Curr.
Org. Chem. 2003, 7, 81−102.
(20) (a) Pourbaix, C.; Carreaux, F.; Carboni, B.; Deleuze, H. Chem.
Commun. 2000, 1275−1276. (b) Mothana, S.; Grassot, J.-M.; Hall, D.
G. Angew. Chem., Int. Ed. 2010, 49, 2883−2887.
1510
dx.doi.org/10.1021/cm3003595 | Chem. Mater. 2012, 24, 1505−1510