CuI/TBAB as a novel efficient catalytic system for Heck reaction in water

Article abstract of DOI:10.1039/c3ra44819c

A novel efficient ligand-free CuI/TBAB catalytic system has been developed for Heck reaction in water without the protection of an inert atmosphere. Both aryl iodides and aryl bromides containing electron-deficient and electron-donating groups reacted smoothly and afforded the corresponding products in moderate to good yields. The Royal Society of Chemistry 2013.

Full text of DOI:10.1039/c3ra44819c

RSC Advances
View Article Online
View Journal
COMMUNICATION
CuI/TBAB as a novel efficient catalytic system for Heck
reaction in water†
Cite this: DOI: 10.1039/c3ra44819c
a
b
a
a
a
Yufang Wang, Qichao Yang, Li Yang, Jianxin Shi and Mingjie Zhang*
Received 25th July 2013
Accepted 11th September 2013
DOI: 10.1039/c3ra44819c
www.rsc.org/advances
11,12
A novel efficient ligand-free CuI/TBAB catalytic system has been due to their ammability, toxicity and volatility.
The media
developed for Heck reaction in water without the protection of an of water has many merits, such as low cost, safety and envi-
inert atmosphere. Both aryl iodides and aryl bromides containing ronmentally benign nature, and only a few examples of Mizor-
13,14
electron-deficient and electron-donating groups reacted smoothly oki–Heck reactions have been reported in aqueous media
and afforded the corresponding products in moderate to good and most of them need the organic ligands. Sometimes,
yields.
development of methods in water is strongly limited by the low
solubility of organic substrates in water and the sensitivity of
chemical groups towards hydrolytic degradation. One of the
Introduction
The palladium-catalyzed Mizoroki–Heck cross-coupling reac-
tion represents one of the most valuable methods for carbon–
1
carbon bond formation in organic synthesis. As a result, many
efforts have been devoted to develop more efficient and selective
2,3
catalytic systems for the Heck cross-coupling reaction. Soluble
palladium compounds, generally phosphine palladium
complexes, are employed most frequently and efficiently in
Scheme 1
4
controlling the reactivity and selectivity of the Heck reaction.
However, most phosphine ligands have some drawbacks such Table 1 Optimization of reaction conditionsa
as expensive, toxic, unrecoverable and sensitive to oxygen and
b
Entry
Base
Solvent
TBAB/mol
Time/h
Yield /%
water, and these drawbacks prevented their large-scale appli-
cation. In addition, the palladium catalyst is expensive and
1
2
3
4
5
6
7
8
9
K
K
2
CO
CO
3
NMP
DMA
DMSO
DMF
1
1
1
1
1
1
1
1
1
1
1
1
0.5
—
1
20
20
20
20
20
20
20
20
20
20
18
24
20
20
20
20
57
37
14
93
70
31
20
49
95
5–7
recovery of it is difficult. Therefore, Heck reactions catalyzed
2
3
by inexpensive transition metals have attracted more interests
K2CO3
8,9
of researchers, including Fe, Co, Ni and Cu. Nevertheless, only
a few papers on Cu-catalyzed Heck cross-coupling reaction have
K
K
2
CO
CO
3
2
3
H
H
H
H
2
2
2
2
O
O
O
O
Et
KOH
PO
3
N
10
been reported. Thus, the development of mild and efficient
copper catalytic systems for the Heck cross-coupling reaction
still remains a challenging area for organic chemists.
K
3
4
NaOH
NaOH
NaOH
NaOH
NaOH
NaOH
NaOH
NaOH
H O
2
c
On the other hand, the Heck reaction is traditionally carried 10
H
H
H
H
H
H
H
2
2
2
2
2
2
2
O
O
O
O
O
O
O
67
11
12
13
14
15
75
95
54
36
out in organic solvents such as dimethyl formamide (DMF),
N-methylpyrrolidone (NMP) and acetonitrile, which oen bring
about signicant safety, health and environmental problems
d
64
e
a
16
1
57
Chemistry Department, School of Science, Tianjin University, Tianjin 300072, China.
E-mail: mjzhangtju@163.com; Fax: +86-022-27403475
a
Reaction conditions: iodobenzene (1.0 mmol), n-butyl acrylate (1.2
b
Chemistry and Pharmaceutical Engineering College, Nanyang Normal University,
mmol), CuI (10% mol), base (1.0 mmol), TBAB (1.0 mmol), solvent (3
ꢀ
mL), 100 C. GC yield determined by using methoxybenzene as
c d
b
Nanyang 473061, China. E-mail: yqch2000@163.com
ꢀ
†
Electronic supplementary information (ESI) available. See DOI:
0.1039/c3ra44819c
internal standard. Reaction temperature is 80 C. CTAB as PTC.
e
TBAH as PTC.
1
This journal is ª The Royal Society of Chemistry 2013
RSC Adv.

View Article Online
RSC Advances
Communication
Table 2 Heck reaction of aryl halides and n-butyl acrylate catalyzed by CuI/
Table 2 (Contd. )
a
TBAB
b
Entry
ArX
Product
Yield /%
b
Entry
1
ArX
Product
Yield /%
g
c
d
14
80
95, 84 , 77
a
Reaction conditions: iodobenzene (1.0 mmol), n-butyl acrylate (1.2
2
3
92
91
mmol), CuI (10% mol), NaOH (1.0 mmol), TBAB (1.0 mmol), H O (3
2
ꢀ
b
c
d
mL), 100 C. Isolated yield. The second run. The third run.
e
f
g
Reaction time is 22 h. Reaction time is 24 h. Reaction time is 24 h.
solutions to circumvent these issues comprises the addition of a
15,16
phase-transfer catalyst (PTC).
In view of the frame work of green chemistry, we prefer to
carry out the cross-coupling reactions in water with tetrabuty-
lammonium bromide (TBAB) as PTC. Herein, we report a
simple, cost-effective, environmentally benign, and efficient
ligand-free CuI/TBAB catalytic system for Heck reaction in water
with good to excellent yields.
4
5
89
78
Results and discussion
6
84
As a model, the Heck reaction of PhI with n-butyl acrylate
18
(Scheme 1) was chosen to optimize the reaction conditions.
The effects of solvent, base, temperature and reaction time
7
8
9
81
77
74
were examined and the results are summarized in Table 1.
Several different solvents (Table 1, entry 1–5) such as DMF,
NMP, DMA, DMSO and water were tested. The results showed
that the reaction catalyzed by CuI/TBAB catalyst system suc-
ꢀ
ceeded in performing in DMF with K
2
CO
3
as base at 100 C for
2
0 h with good yield, 93%. To our great delight, the reaction
proceeded in aqueous media gave 70% yield under the same
condition. Encouraged by this result, several bases were inves-
tigated to nd a best base for the reaction in water. As depicted
in Table 1, Et
20%, respectively). K
Surprisingly, NaOH was found to give a satisfactory yield, 95%
Table 1, entry 9). As the results showed in Table 1, entry 13–14,
3
N and KOH provided very low yield, (31% and
e
1
0
61
PO as base gave a moderate yield 49%.
3
4
(
TBAB plays an important role in the copper-catalyzed Heck-type
reaction in water. In the absence of any TBAB, only 36%
coupling product was obtained aer 20 h and only 54% yield
product was observed when 50 mol% of TBAB was added, but
with 1 mmol TBAB added the yield increased to 95% signi-
cantly. It is because that TBAB could improve the solubility of
the reagent in water. Hexadecyl trimethyl ammonium bromide
(CTAB) and tetra-n-butylammonium hydroxide (TBAH) were
also tested as the PTC, but the results indicated that they were
less effective (Table 1, entry 15 and 16). Heterogeneous Heck
reactions can run better at higher temperatures if reagents,
11
12
13
69
27
f
77
13
products and catalyst can survive such a harsh treatment. To
our great delight, the yield signicantly increased from 67% to
RSC Adv.
This journal is ª The Royal Society of Chemistry 2013

View Article Online
Communication
RSC Advances
a
Table 3 Heck reaction of aryl halides and styrene catalyzed by CuI/TBAB
Table 3 (Contd. )
b
b
Entry
1
ArX
Product
Time/h
20
Yield /% Entry
ArX
Product
Time/h
Yield /%
91
14
24
34
2
3
4
20
20
20
89
85
87
a
Reaction conditions: iodobenzene (1.0 mmol), styrene (1.2 mmol),
ꢀ
CuI (10% mol), NaOH (1.0 mmol), TBAB (1.0 mmol), H
2
O (3 mL), 100 C.
b
Isolated yield.
ꢀ
ꢀ
C
9
(
1
5% when the temperature increased from 80 C to 100
Table 1, entry 10). In addition, when the reaction performed for
8 h, only 75% product was observed (Table 1, entry 11).
However, even the reaction time was prolonged to 24 h, the yield
did not increase markedly (Table 1, entry 12).
With the optimized reaction conditions in hand, various
types of aryl halide coupled with n-butyl acrylate were investi-
gated, as shown in Table 2. The coupling reactions with styrene
were performed under the same reaction conditions as used for
n-butyl acrylate and moderate to high yields of the coupled
products were obtained in Table 3.
5
6
22
22
76
74
The results revealed that the CuI/TBAB catalytic system is
remarkably active and tolerant of a range of functionalities.
Both aryl iodides and aryl bromides bearing electron-decient
as well as electron-donating groups afforded the corresponding
products in moderate to good yields. But aryl iodides performed
better and reacted more quickly than aryl bromides under the
same conditions as shown in Tables 2 and 3. Besides, the
coupling selectivity was also tested and 1-chloro-4-bromo-
benzene was converted to n-butyl-4-chlorocinnamate and (E)-1-
chloro-4-styrylbenzene as the only product, respectively (Table
2, entry 11 and Table 3, entry 11). The comparison of the yields
7
8
9
22
22
81
78
22
22
22
69
85
73
(Table 2, entry 9 and10; Table 3, entry 8 and 9) showed that the
reaction was inuenced somewhat by steric hindrance. It was
worth noting that even 3-bromopyridine coupled with n-butyl
acrylate and styrene could performed well and get the desired
products in 77% and 82% yield, respectively (Table 2, entry 13
and Table 3, entry 12). Besides, the reaction between 3-bromo-
thiophene and n-butyl acrylate also works well to give product in
1
1
0
1
8
0% yield (Table 2, entry 14) and a 75% yield product was
obtained by coupling with 1-bromonaphthol and styrene (Table
, entry 13). Unfortunately, aryl chlorides did not perform as
3
1
1
2
3
24
22
82
75
well under the same condition and lower yields coupling
products were observed (Table 2, entry 12 and Table 3, entry 14).
Furthermore, the catalytic system can be reused for several
times with less decreasing catalytic activity (Table 2, entry 1).
10,17
A possible mechanism was proposed as shown in Scheme 2.
It starts with oxidative addition of aryl halide includes oxidation of
Cu(I) to Cu(III), insertion of olen, and nally b-hydride
elimination.
This journal is ª The Royal Society of Chemistry 2013
RSC Adv.

View Article Online
RSC Advances
Communication
Org. Lett., 2008, 10, 1329; X. M. Ma, Y. X. Zhou, J. C. Zhang,
A. L. Zhu, T. Jiang and B. X. Han, Green Chem., 2008, 10,
59–66; M. Q. Zhao and R. M. Crooks, Angew. Chem., Int.
Ed., 1999, 38, 364–366.
5
A. S. Guram, X. Wang, E. E. Bunel, M. M. Faul, R. D. Larsen
and M. J. Martinelli, J. Org. Chem., 2007, 72, 5104; V. Farina,
Adv. Synth. Catal., 2004, 346, 1553; A. T. Lindhardt,
M. L. H. Mantel and T. Skrydstrup, Angew. Chem., Int. Ed.,
2008, 47, 2668; L. Wu, Z. W. Li, F. Zhang, Y. M. He and
Q. H. Fan, Adv. Synth. Catal., 2008, 350, 846.
6
7
C. A. Fleckenstein and H. Plenio, Green Chem., 2007, 9, 1287;
N. T. S. Phan, M. Van Der Sluys and C. W. Jones, Adv. Synth.
Catal., 2006, 348, 609.
H. M. de Vries, F. J. Parlevliet, L. S. Vondervoort,
J. M. Mommers, H. W. Henderickx, M. M. Walet and J. G. de
Vries, Adv. Synth. Catal., 2002, 344, 996–1002; F. Han, Chem.
Soc. Rev., 2013, 42, 5270–5298; M. R. Gyton, M. L. Cole and
J. B. Harper, Chem. Commun., 2011, 47, 9200–9202.
Scheme 2 A possible mechanism for the copper-catalyzed Heck reaction.
Conclusion
In summary, we have developed a novel efficient ligand-free
CuI/TBAB catalytic system for Heck reaction in water without
the protection of an inert atmosphere. Both aryl iodides and aryl
bromides containing electron-decient and electron-donating
groups performed smoothly and afforded the corresponding
products in moderate to good yields. This reaction will provide a
novel environmentally friendly and economical route for Heck
reaction. Our further investigations to understand the mecha-
nism concerning the origin of the broad scope and high activity
of the catalysts featured herein are currently ongoing in our
laboratory.
8
G. P. Boldini, D. Savoia, E. Tagliavani, C. Trombini and
A. Umani Ronchi, J. Organomet. Chem., 1986, 301, C62;
S. A. Lebedev, V. S. Lopatina, E. S. Petrov and
I. P. Beletskaya, J. Organomet. Chem., 1988, 344, 253;
R. Sustman, P. Hopp and P. Holl, Tetrahedron Lett., 1989,
30, 689; S. Iyer, J. Organomet. Chem., 1995, 490, C27; S. Iyer,
C. Ramesh, A. Sarkar and P. P. Wadgaonkar, Tetrahedron
Lett., 1997, 38, 8113.
A. R. Hajipour and G. Azizi, Green Chem., 2013, 15, 1030–
9
1034; Y. Zhang, G. Y. Song, G. Y. Ma, J. Zhao, C. L. Pan and
X. W. Li, Organometallics, 2009, 28, 3233–3238; B. L. Lin,
L. Liu, Y. Fu, S. W. Luo, Q. Chen and Q. X. Guo,
Organometallics, 2004, 23, 2114–2123; S. Iyer and
V. V. Thakur, J. Mol. Catal. A: Chem., 2000, 157, 275–278;
M. T. Ma and J. M. Lu, Tetrahedron, 2013, 69, 2102–2106.
Acknowledgements
Financial support from the National Natural Science Founda-
tion of China (no. 31201426) was greatly acknowledged.
10 J. H. Li, D. P. Wang and Y. X. Xie, Tetrahedron Lett., 2005, 46,
4
941–4944; C. Waterlot, D. Couturier and B. Rigo,
Notes and references
Tetrahedron Lett., 2000, 41, 317–319; Q. Y. Wu and
E. V. Anslyn, J. Am. Chem. Soc., 2004, 126, 14682–14683;
Y. F. Yang, R. X. Zhou, S. F. Zhao, Q. L. Li and
X. M. Zheng, J. Mol. Catal. A: Chem., 2003, 192, 303–306.
1
2
R. F. Heck, Acc. Chem. Res., 1979, 12, 146–151; I. P. Beletskay
and A. V. Cheprakov, Chem. Rev., 2000, 100, 3009–3066;
G. T. Crisp, Chem. Soc. Rev., 1998, 27, 427–436; M. Casey,
J. Lawless and C. Shirran, Polyhedron, 2000, 19, 517–520.
E. M. Beccalli, G. Broggini, M. Martinelli, N. Masciocchi and
S. Sottocornola, Org. Lett., 2006, 8, 4521; B. Clique,
C. Fabritius, C. Couturier, N. Monteiroand and G. Balme,
Chem. Commun., 2003, 272; S. Yahiaoui, A. Fardost,
11 H. Hagiwara, Y. Sugawara, K. Isobe, T. Hoshi and T. Suzuki,
Org. Lett., 2004, 6, 2325; Q. Yao, E. Kinney and Z. Yang, J. Org.
Chem., 2003, 68, 7528; T. Chen, J. Gao and M. Shi,
Tetrahedron, 2006, 62, 6289; M. R. Gyton, M. L. Cole and
J. B. Harper, Chem. Commun., 2011, 47, 9200.
A. Trejos and M. Larhed, J. Org. Chem., 2011, 76, 2433; 12 D. A. Gerritsma, A. Robertson, J. McNulty and A. Capretta,
B. H. Lipshutz and B. R. Ta, J. Org. Chem., 2003, 68, 7528–
Tetrahedron Lett., 2004, 45, 7629; M. Bakherad,
A. Keivanloo, B. Bahramian and S. Jajarmi, J. Organomet.
Chem., 2013, 724, 206–212.
7531; M. T. Reetz and J. G. de Vries, Chem. Commun., 2004,
559–1564; M. Murata, S. Watanabe and Y. Masuda, J. Org.
1
Chem., 1997, 62, 6458–6459.
13 W. Zhang, H. Qi, L. Li, X. Wang, J. Chen, K. S. Peng and
Z. Wang, Green Chem., 2009, 11, 1194; B. R. Vaddula,
A. Saha, J. Leazer and R. S. Varma, Green Chem., 2012, 14,
2133; N. Iranpoor, H. Firouzabadi, A. Tarassoli and
M. Fereidoonnezhad, Tetrahedron, 2010, 66, 2415–2421.
14 A. Ohtaka, Y. Tamaki, Y. Igawa, K. Egami, O. Shimomura and
R. Nomura, Tetrahedron, 2010, 66, 5642–5646; K. Qiao,
R. Sugimura, Q. Bao, D. Tomida and C. Yokoyama, Catal.
Commun., 2008, 9, 2470–2474; I. Pryjomska-Ray and
3
4
T. Chen, J. Gao and M. Shi, Tetrahedron, 2006, 62, 6289–6294;
A. J. Carmichael, M. J. Earle, J. D. Holbrey, P. B. McCormac
and K. R. Seddon, Org. Lett., 1999, 7, 997–1000;
B. R. Vaddula, A. Saha, J. Leazer and R. S. Varma, Green
Chem., 2012, 14, 2133–2136.
K. Billingsley and S. L. Buchwald, J. Am. Chem. Soc., 2007,
129, 3358; M. T. Reetz and E. Westermann, Angew. Chem.,
Int. Ed., 2000, 39, 165–168; B. H. Lipshutz and B. R. Ta,
RSC Adv.
This journal is ª The Royal Society of Chemistry 2013

View Article Online
Communication
RSC Advances
A. M. Trzeciak, J. Mol. Catal. A: Chem., 2006, 257, 3–8; 18 Procedures for the Heck reaction: all reactions were
Y. Q. Tang, C. Y. Chu, L. Zhu, B. Qian and L. X. Shao,
Tetrahedron, 2011, 67, 9479–9483; Y. Xu, L. Zhang and
Y. Cui, J. Appl. Polym. Sci., 2008, 110, 2996–3000;
S. Bhattacharya, A. Srivastavaa and S. Sengupta,
Tetrahedron Lett., 2005, 46, 3557–3560.
5 D. S. Gaikwad and D. M. Pore, Synlett, 2012, 2631–2634;
G. Zhang, H. Zhou, J. Hu, M. Liu and Y. Kuang, Green
Chem., 2009, 11, 1428.
6 B. H. Lipshutz, G. T. Aguinaldo, S. Ghorai and K. Voigtritter,
Org. Lett., 2008, 10, 1325; B. H. Lipshutz and B. R. Ta, Org.
Lett., 2008, 10, 1329; I. P. Beletskaya, A. N. Kashin,
A. E. Litvinov, V. S. Tyurin, P. M. Valetsky and G. van
Koten, Organometallics, 2006, 25, 154.
carried out under air. Aryl halide (1.0 mmol), olens (1.2
mmol), CuI (10 mol%), NaOH (1.0 mmol), TBAB
(1.0 mol) and 3 mL H O were continuously added to a
2
ꢀ
sealed tube. The reaction mixture was stirred at 100
C
for 20 h. The progress of the reaction was monitored by
GC. Aer completion of the reaction, the catalyst was
ltered easily and the product was extracted with EtOAc,
1
1
the combined organic layers was dried over MgSO
2 h. The solvent was evaporated under reduced pressure
and the desired product puried by ash
chromatography on a silica gel column using hexane/
4
for
1
13
ethyl acetate (5 : 1). H NMR and C NMR spectra (see
ESI†) were recorded in CDCl on a JEOL 300 MHz
3
1
7 Y. B. Huang, C. T. Yang, J. Yi, X. J. Deng, Y. Fu and L. Liu, J.
Org. Chem., 2011, 76, 800–810.
spectrometer with tetramethyl silane (TMS) as internal
standard.
This journal is ª The Royal Society of Chemistry 2013
RSC Adv.