A bifunctional palladated rasta resin for Mizoroki-Heck reactions

Article abstract of DOI:10.1016/j.tetlet.2014.06.012

Bifunctional palladated rasta resins 2b and 2c bearing both phosphino and basic amino groups have been successfully used for Mizoroki-Heck reactions between aryl iodides and alkenes without adding a soluble base. We have also shown that 2c can be easily regenerated after reaction and reused. To the best of our knowledge, this work represents the first use of a bifunctional palladated polymer for a CC bond forming reaction.

Full text of DOI:10.1016/j.tetlet.2014.06.012

Tetrahedron Letters 55 (2014) 4331–4333
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Tetrahedron Letters
journal homepage: www.elsevier.com/locate/tetlet
A bifunctional palladated rasta resin for Mizoroki–Heck reactions
Antoine Derible , Yun-Chin Yang , Patrick H. Toy , Jean-Michel Becht , Claude Le Drian a,
a
b
b
a,
⇑
⇑
a
Université de Haute Alsace, Institut de Science des Matériaux de Mulhouse (UMR-CNRS 7361), 15 rue Jean Starcky, 68057 Mulhouse Cedex, France
The University of Hong Kong, Department of Chemistry, Pokfulam Road, Hong Kong, PR China
b
a r t i c l e i n f o
a b s t r a c t
Article history:
Bifunctional palladated rasta resins 2b and 2c bearing both phosphino and basic amino groups have been
successfully used for Mizoroki–Heck reactions between aryl iodides and alkenes without adding a soluble
base. We have also shown that 2c can be easily regenerated after reaction and reused. To the best of our
knowledge, this work represents the first use of a bifunctional palladated polymer for a CAC bond form-
ing reaction.
Received 5 April 2014
Revised 2 June 2014
Accepted 4 June 2014
Available online 12 June 2014
Ó 2014 Elsevier Ltd. All rights reserved.
Keywords:
Alkenes
Heterogeneous catalysis
Polymers
Green chemistry
The Mizoroki–Heck cross-coupling reaction is one of the most
powerful tools for the creation of alkenyl–aryl bonds. It finds
bifunctional heterogeneous palladium tertiary amine system.12
CarbonAcarbon bond forming reactions have also been reported
in the presence of reusable bifunctional palladium catalysts sup-
1
widespread applications for the syntheses of elaborated molecules
presenting interesting physical,2 biological,3 or pharmaceutical
properties. The Mizoroki–Heck reaction is generally performed by
reacting aryl iodides or bromides with alkenes in the presence of
a soluble base (traditionally a tertiary amine) and a homogeneous
4
13
14
ported on basic zeolites, sepiolites, mesoporous molecular
1
5
16,17
sieves, and silica particles.
Rasta polymers constitute a unique class of heterogeneous sup-
ports composed of very long straight and flexible polymeric chains
5
18
palladium catalyst. Versatile alkenes can be prepared in high
bound to a reticulated core. Their major advantage is that the
yields under mild reaction conditions. However some drawbacks
lie in the use of an expensive palladium catalyst that cannot be
recovered for reuse and the presence of sizeable amounts of pre-
supported reagents are grafted on flexible and solvent-accessible
polymeric chains rather than in the interior of a reticulated poly-
mer bead. However, to date, rasta resins have been only sparsely
6
19
cious metal in products and wastes. In the last decades tremen-
used in organic synthesis, for carbonyl cyanosilylations, addi-
2
0
21
dous work has been devoted to the replacement of soluble
palladium catalysts by heterogeneous reusable catalysts at least
as efficient as their soluble analogs. For this purpose, the precious
metal is generally adsorbed on inorganic supports or grafted on
tions of carbon dioxide to epoxides, Wittig reactions, tandem
2
2
23
Michael–Henry reactions, and transesterifications. We have
also reported the first use of palladated rasta resins bearing
diphenylphosphino groups for Suzuki–Miyaura reactions and
2
4
7
8
25
mineral or organic supports bearing carbene, phosphino, or
Mizoroki–Heck couplings in the presence of a soluble base.
9
amino ligands. We have reported efficient Mizoroki–Heck reac-
Recently we prepared bifunctional rasta resins 1a and 1b bear-
2
6
tions using reusable palladated polystyrenes bearing various phos-
ing both amino and diphenylphosphino groups for chromatogra-
phy-free Wittig olefinations. It was found that 1b gave superior
results than 1a because of decreased nucleophilicity of the amino
1
0,11
phino groups.
In the last decade, some bifunctional heterogeneous reusable
systems bearing both a palladium catalyst and basic groups have
emerged as a promising class of reusable reagents. For example,
the group of Baba has reported allylation of phenols, carboxylic
2
6b
group.
These resins represent the first polymer-supported
bifunctional reagents. We thought that they could be used, after
introduction of palladium, as bifunctional reagents for the Mizor-
oki–Heck reaction. We obtained resin 2b according to our previ-
acids, or 1,3-dicarbonyl derivatives in the presence of
a
2
4,25
ously published procedure (Scheme 1).
3
Since NBu is in some
25
cases more efficient than NEt in the Mizoroki–Heck reaction
3
⇑
Corresponding authors. Tel.: +33 (0)3 89 60 87 22; fax: +33 (0)3 89 60 87 99 (J.-
M.B.); tel.: +33 (0)3 89 60 87 91; fax: +33 (0)3 89 60 87 99 (C.L.D.).
and since the synthesis of these rasta resins is easy and versatile,
we also prepared resin 1c (according to a procedure analogous to
E-mail addresses: jean-michel.becht@uha.fr (J.-M. Becht), claude.le-drian@uha.fr
2
6
that reported for 1b ) which gave 2c (Scheme 1). TEM images
(
C. Le Drian).
http://dx.doi.org/10.1016/j.tetlet.2014.06.012
040-4039/Ó 2014 Elsevier Ltd. All rights reserved.
0

4
332
A. Derible et al. / Tetrahedron Letters 55 (2014) 4331–4333
Table 1
Optimization of the reaction conditions
50
5
25
O
N
OMe
MeO
I
PPh2
Rasta resin 2b or 2c
NR2
+
:
JandaJel core
Solvent, 20 h
CO Me
2
CO Me
1a: R = Et ; 1b: R = iPr ; 1c: R = nBu
2
3
a
Pd2dba3, toluene,
Entrya
Solventc
1
b
2b: R = iPr, %N: 3.52, %P: 1.09, %Pd: 0.1
2c: R = n-Bu, %N: 2.53, %P: 1.21, %Pd: 0.1
Catalyst
Yield (%)
1
c
1b
d
d
d
d
e
100 °C, 20 h
2b
2b
2b
2b
2b
2b
2b
2b
2c
Toluene
1,4-Dioxane
Acetonitrile
EtOH
DMA
DMSO
DMF/toluene 1:2
DMF
DMF
No reaction
No reaction
No reaction
No reaction
No reaction
<10e
b
2
c
Scheme 1. Preparation of palladated rasta resins 2b and 2c.
3
c
4
b
5
b
6
b
d
7
No reaction
(
Fig. 1a) of catalyst 2c show the presence of nanoaggregates of pal-
ladium, as was found in our previous work with phosphinated res-
b
e
8
90
b
e
9
99
2
5
ins. Herein we present the use of palladated resins 2b and 2c
obtained from 1b and 1c (Scheme 1) for the Mizoroki–Heck reac-
tion. With these resins this coupling can be performed without
addition of any soluble reagent.
Noteworthily, 2b and 2c can be handled and stored without
particular precautions. The reaction conditions were then opti-
mized using 4-iodoanisole and methyl acrylate as model substrates
a
Reactions performed with 4-iodoanisole (1.0 equiv, 0.2 mmol), methyl acrylate
2.0 equiv, 0.4 mmol), resin 2b, (containing ca. 1.2 equiv of base and 4.5 mequiv of
supported Pd, 96 mg) or 2c (containing ca. 1.2 equiv of base and 6.2 mequiv of
(
supported Pd, 133 mg) in 2 mL of solvent.
b
Reactions performed at 100 °C.
Reactions performed in refluxing solvent.
Aryl iodide was recovered unchanged after reaction.
Isolated yields.
c
d
e
(
Table 1).
It turned out that running the reaction in toluene, 1,4-diox-
ane, acetonitrile, EtOH, DMA, DMSO, or in a 1:2 DMF/toluene
mixture11 was unsuccessful (entries 1–7). Gratifyingly, excellent
yields were obtained using either 2b or 2c in DMF (entries 8
basic groups were regenerated by treatment with NBu
3
in DMF
2
6b
at rt for 1 h
and the recovered 2c was reused in another Mizor-
oki–Heck reaction. We found that 2c could be used five times with
yields ranging from 99% to 70%.
TEM images of catalyst 2c before use, after one use (Fig. 1), and
after five uses showed also that no significant change was observed
since palladium aggregates of ca. 10 nm size were observed in each
case.
and 9). Noteworthily, no reaction was observed by replacing aryl
iodide by
a
bromide such as 4-bromoanisole or 4-
bromoacetophenone.
A hot filtration test was then performed in order to determine
if soluble palladium entities participate in this coupling. For this
purpose, the reaction was performed according to Table 1, entry
Mizoroki–Heck couplings were then performed by reacting var-
ious aryl iodides and alkenes in the presence of 2c (Table 3).29 The
desired alkenes were obtained using aryl iodides bearing electron-
donating or electron-attracting groups with yields ranging from
69% to 99% (entries 1–9). It is noteworthy that sterically hindered
aryl iodides were reacted successfully (entries 4–6). Replacing
methyl acrylate by styrene afforded the corresponding alkene in
83% yield (entry 10). However, acrylonitrile gave only traces of
alkene.
In conclusion, we have described the first bifunctionalized poly-
mer bearing both a supported palladium catalyst and a supported
base for Mizoroki–Heck reactions. According to Green Chemistry
principles, the purification step of the product can then be avoided
and the use of a scarce natural resource, palladium, is minimized.
9
. After 7 h of reaction at 100 °C, the rasta resin 2c was filtered
off on a 0.2 m membrane (yield at that point: 47%), NBu
1.2 equiv) was added and the filtrate was heated for another
l
3
(
1
3 h at 100 °C (yield at that point: 99%). In accordance with a
25
previous report from our group, we conclude therefore that
soluble palladium entities catalyze the Mizoroki–Heck reaction.
However, the exact nature of the catalytic species is not well
known. We also measured that the amount of palladium pres-
ent in the reaction mixture at the normal end of the cross-cou-
pling was variable: 5–12%. We determined that, on average, 90%
2
7
of the initial amount of palladium was still present in the cata-
lyst after each use.28
The possibility to reuse 2c was then ascertained (Table 2): after
reaction the rasta resin was filtered on a 0.2 lm membrane, the
(
a)
(b)
Figure 1. TEM images of catalyst 2c: (a) freshly prepared; (b) after one use.

A. Derible et al. / Tetrahedron Letters 55 (2014) 4331–4333
4333
Table 2
6. (a) Wang, L.; Green, L.; Li, Z.; McCabe Dunn, J.; Bu, X.; Welch, C. J.; Li, C.; Wang,
Recycling tests (conditions of Table 1, entry 9)
T.; Tu, Q.; Bekos, E.; Richardson, D.; Eckert, J.; Cui, J. Org. Process Res. Dev. 2011,
1
5, 1371–1376; (b) Girgis, M. J.; Kuczynski, L. E.; Berberena, S. M.; Boyd, C. A.;
Run
1
2
3
4
5
Kubinski, P. L.; Scherholz, M. L.; Drinkwater, D. E.; Shen, X.; Babiak, S.; Lefebvre,
B. G. Org. Process Res. Dev. 2008, 12, 1209–1217.
(a) Yin, L.; Liebscher, J. Chem. Rev. 2007, 107, 133–173; (b) Polshettiwar, V.;
Molnár, A. Tetrahedron 2007, 63, 6949–6976; (c) Borja, G.; Monge-Marcet, A.;
Pleixats, R.; Parella, T.; Cattoën, X.; Wong Chi Man, M. Eur. J. Org. Chem. 2012,
Yielda
99
99
90
78
70
7
8
.
.
a
Isolated yields.
3625–3635.
(a) Lu, J.; Toy, P. H. Chem. Rev. 2009, 109, 815–838; (b) Luo, T.-T.; Xue, C.; Ko, S.-
L.; Shao, Y.-D.; Wu, C.-J.; Kuo, Y.-M. Tetrahedron 2005, 61, 6040–6045.
Table 3
Mizoroki–Heck reactions (conditions of Table 1, entry 9)
9. Magnetically heterogeneous reusable palladium catalyst have also been
reported for various CAC bond forming reactions: (a) Vaddula, B. R.; Saha, A.;
Leazer, J.; Varma, R. S. Green Chem. 2012, 14, 2133–2136; (b) Li, P.; Wang, L.;
Wang, G. W. Adv. Synth. Catal. 2012, 354, 1307–1318; (c) Baruwati, B.; Guin, D.;
Manorama, S. V. Org. Lett. 2007, 9, 5377–5380; (d) Jin, M.-J.; Lee, D.-H. Angew.
Chem., Int. Ed. 2010, 49, 1119–1122.
R1
R1
I
Rasta resin 2c
+
10. Schweizer, S.; Becht, J.-M.; Le Drian, C. Adv. Synth. Catal. 2007, 349, 1150–1158.
DMF, 100 °C, 20 h
R2
a-j
11. Diebold, C.; Schweizer, S.; Becht, J.-M.; Le Drian, C. Org. Biomol. Chem. 2010, 8,
R2
4
834–4836.
2. Noda, H.; Motokura, K.; Miyaji, A.; Baba, T. Adv. Synth. Catal. 2013, 355, 973–
80.
3
1
9
Entrya
R1
R2
Compound
Yieldb (%)
13. (a) Corma, A.; Garcia, H.; Leyva, A. Appl. Catal., A 2002, 236, 179–185; (b)
Corma, A.; Garcia, H.; Leyva, A.; Primo, A. Appl. Catal., A 2003, 247, 41–49.
1
2
3
4
5
6
7
8
9
4-OMe
4-Me
3-Me
2-Me
2-iPr
2-Br
CO
2
CO
2
CO
2
CO
2
CO
2
CO
2
CO
2
CO
2
CO
2
Ph
Me
Me
Me
Me
Me
Me
Me
Me
Me
3a
3b
3c
3d
3e
3f
3g
3h
3i
99
99
99
98
69
98
99
98
95
83
1
1
4. Corma, A.; Garcia, H.; Leyva, A.; Primo, A. Appl. Catal., A 2004, 257, 77–83.
5. (a) Demel, J.; Cejka, J.; Stepnicka, P. J. Mol. Catal. A: Chem. 2007, 274, 127–132;
(
b) Demel, J.; Lamac, M.; Cejka, J.; Stepnicka, P. ChemSusChem 2009, 2, 442–445.
1
1
6. Dickschat, A. T.; Surmiak, S.; Studer, A. Synlett 2013, 1523–1528.
7. Heterogeneous bifunctional catalysts have been disclosed for other reactions;
For tandem Heck-asymmetric dihydroxylation of olefins see: (a) Choudary, B.
M.; Chowdari, N. S.; Jyothi, K.; Kumar, N.; Kantam, M. L. Chem. Commun. 2002,
586–587; For aerobic oxidation followed by asymmetric CAC bond formation
see: (b) Miyamura, H.; Choo, G. C. Y.; Yasukawa, T.; Yoo, W.-J.; Kobayashi, S.
Chem. Commun. 2013, 9917–9919; For one-step hydrogenation–esterification
of furfural and acetic acid see: (c) Yu, W.; Tang, Y.; Mo, L.; Chen, P.; Lou, H.;
Zheng, X. Catal. Commun. 2011, 13, 35–39.
H
3-CF
4-Ac
3
1
0
4-OMe
3j
a
Reactions performed with aryl iodide (1.0 equiv, 0.2 mmol), alkene (2.0 equiv,
.4 mmol), and resin 2c (containing ca. 1.2 equiv of base and 6.2 mequiv of sup-
0
18. (a) Hodges, J. C.; Harikrishnan, L. S.; Ault-Justus, S. J. Comb. Chem. 2000, 2, 80–
88; (b) Lindsley, C. W.; Hodges, J. C.; Filzen, G. F.; Watson, B. M.; Geyer, A. G. J.
Comb. Chem. 2000, 2, 550–559; (c) McAlpine, S. R.; Lindsley, C. W.; Hodges, J. C.;
Leonard, D. M.; Filzen, G. F. J. Comb. Chem. 2001, 3, 1–5; (d) Wisnoski, D. D.;
Leister, W. H.; Strauss, K. A.; Zhao, Z.; Lindsley, C. W. Tetrahedron Lett. 2003, 44,
ported Pd, 133 mg) in 2 mL of DMF.
b
Isolated yields.
4
321–4325; (e) Pawluczyk, J. M.; McClain, R. T.; Denicola, C.; Mulhearn, J. J., Jr.;
Acknowledgments
Rudd, D. J.; Lindsley, C. W. Tetrahedron Lett. 2007, 48, 1497–1501; (f) Fournier,
D.; Pascual, S.; Montembault, V.; Fontaine, L. J. Polym. Sci., Part A 2006, 44,
5316–5328; (g) Fournier, D.; Pascual, S.; Montembault, V.; Haddleton, D. M.;
Fontaine, L. J. Comb. Chem. 2006, 8, 522–530.
This research was funded in part by the Research Grants Council
of the Hong Kong SAR, PR China (Project No. HKU 705209P). We are
also grateful to the Centre National de la Recherche Scientifique
1
2
9. Teng, Y.; Toy, P. H. Synlett 2011, 551–554.
0. Lu, J.; Toy, P. H. Synlett 2011, 659–662.
(
CNRS) for financial support, to the Université de Haute Alsace
21. Leung, P. S.-W.; Teng, Y.; Toy, P. H. Synlett 2010, 1997–2001.
1
2
2. Bonollo, S.; Lanari, D.; Angelini, T.; Pizzo, F.; Marrocchi, A.; Vaccaro, L. J. Catal.
012, 285, 216–222.
3. Yang, Y. C.; Leung, D. Y. C.; Toy, P. H. Synlett 2013, 1870–1874.
for a grant to A. Derible, to Dr. Didier Le Nouën (EA 4566) for H
NMR spectra and to Dr. Loïc Vidal (UMR-CNRS 7361) for TEM
images.
2
2
24. Diebold, C.; Becht, J.-M.; Lu, J.; Toy, P. H.; Le Drian, C. Eur. J. Org. Chem. 2012,
93–896.
8
2
2
5. Derible, A.; Becht, J.-M.; Le Drian, C. Tetrahedron Lett. 2013, 54, 4207–4209.
6. (a) Leung, P. S.-W.; Teng, Y.; Toy, P. H. Org. Lett. 2010, 12, 4996–4999; (b) Teng,
Y.; Lu, J.; Toy, P. H. Chem. Asian J. 2012, 7, 351–359.
7. Kashin, A. S.; Ananikov, V. P. J. Org. Chem. 2013, 78, 11117–111125.
8. For the method of palladium determination see Ref. 24.
References and notes
1
2
.
.
Heck, R. F.; Nolley, J. P., Jr. J. Org. Chem. 1972, 37, 2320–2322.
Tietze, L. F.; Kettschau, G.; Heuschert, U.; Nordmann, G. Chem.-Eur. J. 2001, 7,
2
2
2
3
68–373.
(a) Nicolaou, K. C.; Bulger, P. G.; Sarlah, D. Angew. Chem., Int. Ed. 2005, 44, 4442–
489; (b) Häberli, A.; Leumann, C. J. Org. Lett. 2001, 3, 489–492; (c) Burke, T. R.,
9. Synthesis of alkenes 3a–j. Catalyst 2c (prepared according Ref. 26b, 133 mg,
3
4
.
.
6
1
.2 equiv of Pd) was added to
.0 m equiv), alkene (0.40 mmol, 2.0 equiv) in DMF (2 mL). The reaction
a solution of aryl iodide (0.20 mmol,
4
Jr.; Liu, D.-G.; Gao, Y. J. Org. Chem. 2000, 65, 6288–6292.
mixture was heated at 100 °C for 20 h. After cooling to rt, compound 2c was
(a) Danishefsky, S. J.; Masters, J. J.; Young, W. B.; Link, J. T.; Snyder, L. B.; Magee,
T. V.; Jung, D. K.; Isaacs, R. C. A.; Bornmann, W. G.; Alaimo, C. A.; Coburn, C. A.;
Di Grandi, M. J. J. Am. Chem. Soc. 1996, 118, 2843–2859; (b) Li, J.; Jeong, S.; Esser,
L.; Harran, P. G. Angew. Chem., Int. Ed. 2001, 40, 4765–4769; (c) Nicolaou, K. C.;
Sorensen, E. J. Classics in Total Synthesis; Wiley-VCH: New York, 1996.
Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009–3066.
filtered off under vacuum using a 0.2 m membrane. The mixture of solvents
l
was concentrated under vacuum to afford pure 3a–j after drying under
vacuum (0.1 mbar). The catalyst 2c was then regenerated by reaction with
NBu (0.16 mL, 0.66 mmol, 3.3 equiv) in DMF at rt for 3 h. Compound 2c was
3
then filtered under vacuum, washed with Et
vacuum.
2
O (2 mL), and dried under
5
.