Open-air oxidative Mizoroki-Heck reaction of arylsulfonyl hydrazides with alkenes

Article abstract of DOI:10.1039/c6ra03188a

A palladium(ii)-catalyzed oxidative Mizoroki-Heck reaction of arylsulfonyl hydrazides with alkenes was developed employing atmospheric air as the sole oxidant in an open-vessel manner. By using palladium(ii) acetate associating with inexpensive, air-stable and moisture stable pyridine ligand L9 as the catalyst system, the efficiency of the reaction could be significantly enhanced. A wide range of arylsulfonyl hydrazides underwent the oxidative Mizoroki-Heck reaction with alkenes smoothly. Good-to-excellent product yields and excellent regio- and stereoselectivity were achieved. Functional groups such as halo, ester etc. were well-tolerated under these optimized reaction conditions.

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Open-air oxidative Mizoroki–Heck reaction of
arylsulfonyl hydrazides with alkenes†
Cite this: RSC Adv., 2016, 6, 27584
*
*
On Ying Yuen, Chau Ming So and Fuk Yee Kwong
A palladium(II)-catalyzed oxidative Mizoroki–Heck reaction of arylsulfonyl hydrazides with alkenes was
developed employing atmospheric air as the sole oxidant in an open-vessel manner. By using
palladium(II) acetate associating with inexpensive, air-stable and moisture stable pyridine ligand L9 as the
catalyst system, the efficiency of the reaction could be significantly enhanced. A wide range of
arylsulfonyl hydrazides underwent the oxidative Mizoroki–Heck reaction with alkenes smoothly.
Good-to-excellent product yields and excellent regio- and stereoselectivity were achieved. Functional
groups such as halo, ester etc. were well-tolerated under these optimized reaction conditions.
Received 3rd February 2016
Accepted 6th March 2016
DOI: 10.1039/c6ra03188a
www.rsc.org/advances
reaction is the reaction mechanism. The former is that elec-
trophiles act as self-oxidant for carrying out oxidative addition
Introduction
to palladium(0) species to form arylpalladium(II) intermediates.
The latter is that extra oxidants such as oxygen or copper(II) salts
are required to re-oxidize palladium(0) species to palladium(II)
complexes. Aromatics,9 arylcarboxylic acids,10 arylboronic acid
derivatives,11 arylphosphonic acids,12 arylsulfonic acids13 and its
sodium salts,14 arylhydrazines,15 carbazates16 and aroyl hydra-
zides17 were shown to effectively couple with alkenes in the
oxidative reactions (Scheme 1).
The palladium-catalyzed Mizoroki–Heck reaction is one of the
most powerful tools for incorporating a C–C double bond in
organic synthesis1 and plays an important role in both synthetic
laboratories and industrial applications.2 In the traditional
Heck reaction, aryl halides act as electrophiles and couple with
alkenes in the presence of palladium catalysts under basic
conditions to produce higher substituted alkenes.3 Apart from
aryl halides, aryl sulfonates,4 aryl diazonium salts,5 arylsulfonyl
halides,6 and arylcarboxylic acid derivatives7 are also effective
aryl sources in the Mizoroki–Heck type reactions.
Arylsulfonyl hydrazides are recently rising electrophiles
which are readily accessible solids, stable in air and moisture
conditions and can be easily prepared in one step from aryl-
sulfonyl chlorides and hydrazine hydrates.18 Particular note-
worthy is that they can serve as arylating agents, which are
subjected to denitrogenation and desultation to generate the
aryl source for the oxidative palladium-catalyzed coupling
reactions.19 Oxidative Heck reaction,19a oxidative direct arylation
of heteroarenes,19b-d oxidative conjugate addition reaction,19e
oxidative homo-coupling reaction,19f oxidative Suzuki reac-
tion19g and oxidative Hiyama reaction19h have been reported.
Currently, most of these reactions are using excess amount
of Cu(OAc)2 or pure oxygen as oxidant. We envision that the use
of the atmospheric air in open-vessel manner is one of the most
attractive protocols for the oxidative Heck reaction because of
the following advantages: (1) avoid the handling of dangerous
and hazardous pressurized gas tube, (2) allow to release the
extra gaseous pressure generates from denitrogenation (N2) and
desultation (SO2) of arylsulfonyl hydrazides under high
temperature, (3) can provide a constant oxygen concentration
over the whole reaction period which may maximize the utility
of this technology for genuine applications. However, in
general, only inferior yields were obtained when air is used as
the reaction atmosphere especially for the Heck-type
The oxidative Heck reaction is also an excellent pathway to
access substituted alkene products.8 The most striking differ-
ence between traditional Heck reaction and oxidative Heck
Scheme 1 Traditional Heck reaction of aryl halides and oxidative Heck
reaction using other aryl sources with alkenes.
State Key Laboratory of Chirosciences and Department of Applied Biology and
Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kwoloon,
Hong Kong, China. E-mail: chau.ming.so@polyu.edu.hk; fuk-yee.kwong@polyu.edu.hk
† Electronic supplementary information (ESI) available. See DOI:
10.1039/c6ra03188a
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Table 1 Initial screening of palladium-catalyzed oxidative Mizoroki– Table 2 Ligand screening for palladium-catalyzed oxidative Mizor-
Heck-type reaction of arylsulfonyl hydrazidesa
oki–Heck-type reaction of arylsulfonyl hydrazidesa,b
Entry
Catalyst (mol%)
Solvent
% yieldb
1
2
3
4
5
6
7
8
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd(OAc)2 (10)
Pd2(dba)3 (10)
Pd(COOCF3)2 (10)
Pd(acac)2 (10)
PdCl2(CH3CN)2 (10)
PdCl2(PPh3)2 (10)
PdCl2(COD)2 (10)
PdCl2 (10)
Dioxane
DMF
DMA
NMP
DMSO
THF
t-BuOH
Toluene
MeCN
PhCN
AcOH
DMF
DMF
DMF
DMF
DMF
DMF
DMF
40
55
47
40
14
7
20
5
9
13
26
17
15
41
23
51
32
Trace
40
10
11
12
13
14
15
16
17
18
a
Reaction conditions: 4-methylbenzenesulfonyl hydrazide (0.45 mmol),
a
Reaction condition: 4-methylbenzenesulfonyl hydrazide (0.45 mmol),
styrene (0.3 mmol), Pd source (10 mol%) and solvent (3.0 mL) were
styrene (0.3 mmol), Pd(OAc)2 (10 mol%), L (20 mol%), DMF (3.0 mL)
b
were stirred at 80 ꢀC for 16 h under air. Calibrated GC yields were
b
stirred at 90 ꢀC for 16 h under air. Calibrated GC yields were
reported using dodecane as internal standard.
c
reported using dodecane as internal standard. The reaction was
conducted at 90 ꢀC.
reactions.19a,e Herein, we attempted to advance this oxidative
Heck reaction by using atmospheric air in open air manner.
oxidation particularly with respect to competing Pd(0) aggregation
so as to promote catalyst turnover, improve catalyst stability and
increases regio- and stereoselectivity of the reaction.20
Uemura's Pd(OAc)2/pyridine catalyst system were found to
promote the oxidation of Pd(0) to Pd(II) in the aerobic alcohol
oxidation reaction.20 Herein, we adopt the Pd(OAc)2/pyridine
catalyst system for the oxidative Heck reaction of arylsulfonyl
hydrazides with alkenes for the rst time.
Results and discussion
In order to test the feasibility of palladium-catalyzed oxidative
Mizoroki–Heck reaction of arylsulfonyl hydrazides with alkenes,
a series of screenings was conducted (Table 1). 4-Methyl-
benzenesulfonyl hydrazide and styrene were used as the
benchmark substrates. In surveying of common solvents, DMF
gave the best result (Table 1, entry 2 and entries 1–11). The
initial screening of palladium sources (Table 1, entries 12–18)
indicated that Pd(OAc)2 was the suitable Pd source for this
coupling reaction.
Aer the detailed optimization of solvents and Pd sources,
we still found that the product yield was unsatisfactory. Inspired
by the poor result of Pd(OAc)2/DMSO system which is one of the
well-known catalyst systems for the palladium-catalyzed oxidative
reactions and also analogy to the aerobic alcohol oxidation reac-
tion and oxidative amination of olens reaction,20 we were
intrigued that the inferior yield may result from the slow aerobic
oxidation of Pd(0) species to Pd(II), especially under air atmosphere
which is low oxygen concentration. Pd(0) species easily aggregate
and agglomerate to unreactive palladium black and retard the
coupling catalysis in the ligand-free Heck reactions. Oxidatively
stable ligands have been identied to enhance the rate of Pd(0)
We found that when pyridine was added, the product yield
improved satisfactorily from 55% to 77% (Table 2, L1). When
ꢀ
ꢀ
the reaction temperature was lowered from 90 C to 80 C, the
product yield remained the unaffected. An evaluation of
different substituted pyridine ligands L2–L11 indicated that
phenyl isonicotinate (L9) gave the best yield of product.
Although the electronic inuence of the pyridine-type ligands in
this oxidative heck reaction is still unclear, sterically hindered
pyridine type ligands L10–L11 which hinder the facial coordi-
nation to Pd center show minor enhancing effect of the product
yield that imply the importance of the ligand coordination effect.
With the Pd(OAc)2/L9 system in hand, we next investigated
the scope of Mizoroki–Heck reaction of arylsulfonyl hydrazides
with alkenes. The results were summarized in Table 3. A
wide range of arylsulfonylhydrazides carried out oxidative Miz-
oroki–Heck reaction with styrene smoothly to give 1,2-disubsti-
tuted alkenes in moderate-to-excellent yields under air
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atmosphere. ortho-Substituted arylsulfonyl hydrazides were
good coupling partners for this reaction (Table 3, compounds
3bk and 3gk). Electron-rich arylsulfonyl hydrazide afforded
moderate yield (Table 3, compound 3hk). The highly sterically
hindered arylsulfonyl hydrazide coupled well with styrene
(Table 3, compound 3ik). Apart from styrene, a variety of
substituted styrenes and acrylates was examined and provided
good to excellent product yields.21 To our delight, the highly
sterically hindered arylsulfonyl hydrazide coupled with butyl
acrylate in good yield (Table 3, compound 3in). Both of electron-
decient and electron-rich substituents on styrenes were feasible
cross-coupling partners (Table 3, compounds 3ao, 3ap, 3aq, 3as,
3at and 3au). The highly sterically crowded 2,4,6-trimethylstyrenes
proceeded well with 4-chlorobenzenesulfonyl hydrazide partner
smoothly (Table 3, compound 3fv). Notably, bromo and chloro
groups were compatible under these optimized reaction condi-
tions that are useful moieties for further chemical trans-
formations using other coupling technology (Table 3,
compounds 3, 3aq, 3au and 3fv).
Table 3 Palladium-catalyzed oxidative Mizoroki–Heck-type reaction
of arylsulfonyl hydrazides and olefinsa,b
In order to have a better understanding of the effect of pyridine
ligand towards the reaction rate of palladium-catalyzed oxidative
Mizoroki–Heck reaction, 4-methylbenzenesulfonyl hydrazide and
styrene were selected as substrates for the kinetic studies
(Scheme 2). Two sets of parallel experiment in the presence of L9
and absence of L9 were conducted which was represented by
blue line and red line in Scheme 2 respectively. The reaction rates
in both cases were essentially the same within the rst 30 min,
which indicated the reaction rate was not obviously promoted by
the presence of L9. At 45 min, on the wall of the reaction tube,
a small amount of palladium black was observed in the absence of
L9 while palladium black was not observed in the presence of L9.
In the absence of the L9, the reaction rate decreased more signif-
icantly at 90 min and the reaction rate became steady aer 180
min. In contrast, in the presence of L9, the reaction rate decreased
relatively slower in the rst 120 min and the reaction rate became
steady aer 240 min. Furthermore, in the presence of the L9,
a higher turnover number could be obtained within the same
reaction period. This kinetic result implied that the coordination
of the pyridine ligand to the Pd center may reduce the possibility of
the formation of inactive Pd black so that the reaction can be
promoted by a higher concentration of the active Pd species during
the course of the reaction.
A proposed catalytic cycle, as adapted from the mechanistic
studies performed on the Pd-catalyzed coupling reactions of aryl-
sulfonyl hydrazides and Pd(OAc)2/pyridine oxidation reaction
mechanism, is shown in Scheme 3.19,20 The coordination of the
pyridine ligand to Pd(OAc)2 generate complex I which is subse-
quently converted to complex II and HOAc by deprotonation with
arylsulfonyl hydrazide. Complex II undergoes b-hydride elimina-
tion to give complex III and sulfonyl diazene. Displacement of
complex I with sulfonyl diazene gives complex IV. Liberation of N2
with complex IV provides the complex V, and successive extrusion
of SO2 affords complex VI. The coordination of alkene to complex
VI followed by alkene insertion generates complex VII. Complex VII
undergoes b-hydride elimination to generate complex III. Reduc-
tive elimination of complex III generates complex VIII, and the
complex I is regenerated by oxidation.
a
Reaction conditions: arylsulfonyl hydrazide (0.45 mmol), alkene (0.3
mmol), Pd(OAc)2 (10 mol%), L9 (20 mol%) and DMF (3 mL) were
b
c
stirred at 80 ꢀC for 16 h under air. Isolated yield. The reaction was
d
e
conducted at 70 ꢀC. The reaction was conducted at 100 ꢀC. Close
system was used. f The reaction was conducted for 24 h.
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equipped with a Teon-coated magnetic stir bar. Precomplexation
was applied by adding DMF (1 mL) in to the vial. The palladium
complex stock solution was stirred for 10 minutes. Arylsulfonyl
hydrazide (0.45 mmol) and alkenes (0.3 mmol) were loaded into
the vial. DMF (2 mL) was added with continuous stirring at room
temperature. The vial was tted with an air condenser as cooler
and then placed into a preheated oil bath which the temperature
was indicated in the table and vigorously stirred for 16 h. Aer the
completion of reaction, the reaction vial was allowed to cool at
room temperature. Ethyl acetate (ꢁ10 mL) was added. The organic
layer was subjected to GC analysis. Aer analyzing GC spectra, the
crude product in the organic layer was extracted and the vial
washed with ethyl acetate. The ltrate was concentrated under
reduced pressure. The crude product was puried by ash column
chromatography on silica gel (230–400 mesh) to afford the
desired product.
Scheme 2 Kinetic study of the effect of the pyridine ligand L9 on the
oxidative Mizoroki–Heck-type reaction of 4-methylbenzenesulfonyl
hydrazide with styrene.
Acknowledgements
We thank the Research Grants Council of Hong Kong,
(CRF: C5023-14G), and General Research Fund (GRF: PolyU
153008/14P) and State Key Laboratory of Chirosciences for
nancial support. Grateful to Prof. Albert S. C. Chan's research
group (PolyU Hong Kong) for sharing of GC-FID and GC-MS
instruments.
Notes and references
1 (a) R. F. Heck, Acc. Chem. Res., 1979, 12, 146; (b) G. D. Daves Jr
and A. Hallberg, Chem. Rev., 1989, 89, 1433; (c) W. Cabri and
I. Candiani, Acc. Chem. Res., 1995, 28, 2; (d) G. T. Crisp, Chem.
Soc. Rev., 1998, 27, 427; (e) I. P. Beletskaya and
A. V. Cheprakov, Chem. Rev., 2000, 100, 3009; (f) A. F. Littke
and G. C. Fu, Angew. Chem., Int. Ed., 2002, 41, 4176.
2 N. J. Lawrence, in Preparation of Alkenes: a Practical Approach,
ed. J. M. J. Williams, Oxford University Press, Oxford, UK,
1995.
3 (a) T. Mizoroki, K. Mori and A. Ozaki, Bull. Chem. Soc. Jpn.,
1971, 44, 581; (b) R. F. Heck and J. P. Nolley, J. Org. Chem.,
1972, 37, 2320; (c) X.-F. Wu, P. Anbarasan, H. Neumann
and M. Beller, Angew. Chem., Int. Ed., 2010, 49, 9047.
4 (a) Q.-Y. Chen and Z.-Y. Yang, Tetrahedron Lett., 1986, 27,
1171; (b) T. M. Gøgsig, A. T. Lindhardt, M. Dekhane,
J. Grouleff and T. Skrydstrup, Chem.–Eur. J., 2009, 15, 5950.
5 For reviews, see: (a) J. G. Taylor, A. M. Moro and
C. R. D. Correia, Eur. J. Org. Chem., 2011, 1403; (b)
Scheme 3 Proposed catalytic cycle.
Conclusions
In summary, we have reported the rst examples of oxidative
Mizoroki–Heck reaction of arylsulfonyl hydrazides with alkenes in
an open-air manner using the stable and inexpensive pyridine
ligand L9. The Pd(OAc)2/L9 catalyst system was effective for the
coupling of a wide range of arylsulfonyl hydrazides and alkenes. It
was noteworthy that the reaction was conducted under atmo-
spheric air. The preliminary kinetic study result showed that
pyridine ligand L9 may reduce the Pd(0) aggregation so as to
promote catalyst turnover. We expect this convenient synthetic
method will be useful in the organic synthesis.
ˇ
A. Roglans, A. Pla-Quintana and M. Moreno-Manas, Chem.
Rev., 2006, 106, 4622. For recent examples, see: (c) F. Le
Callonnec, E. Fouquet and F.-X. Felpin, Org. Lett., 2011, 13,
2646; (d) E. W. Werner and M. S. Sigman, J. Am. Chem.
Soc., 2011, 133, 9692.
6 (a) M. Miura, H. Hashimoto, K. Itoh and M. Nomura,
Tetrahedron Lett., 1989, 30, 975; (b) S. R. Dubbaka and
P. Vogel, Chem.–Eur. J., 2005, 11, 2633.
Experimental section
General procedure for the oxidative heck reaction of
arylsulfonyl hydrazides with alkenes
All reagents were weighted in air and the reactions were performed
in an open vessel. Pd(OAc)2 (0.0068 g, 0.03 mmol) and phenyl
isonicotinate (Pd : L ¼ 1 : 2) were loaded into a 40 mL vial
7 (a) C.-M. Andersson and A. Hallberg, J. Org. Chem., 1988, 53,
235; (b) M. S. Stephan, A. J. J. M. Teunissen, G. K. M. Verzijl
and J. G. de Vries, Angew. Chem., Int. Ed., 1998, 37, 662; (c)
This journal is © The Royal Society of Chemistry 2016
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L. J. Gooßen, J. Paetzold and L. Winkel, Synlett, 2002, 1721;
(d) L. J. Gooßen and J. Paetzold, Angew. Chem., Int. Ed.,
2002, 41, 1237; (e) L. J. Gooßen and J. Paetzold, Angew.
Chem., Int. Ed., 2004, 43, 1095; (f) T. Sugihara, T. Satoh and
M. Miura, Tetrahedron Lett., 2005, 46, 8269.
8 For reviews, see: (a) B. Karimi, H. Behzadnia, D. Elhamifar,
P. F. Akhavan, F. K. Esfahani and A. Zamani, Synthesis,
2010, 1399; (b) R. Rossi, F. Bellina and M. Lessi, Synthesis,
2010, 4131; (c) J. Le Bras and J. Muzart, Chem. Rev., 2011,
111, 1170.
A. V. D. Hoogenband and A. J. Minnaard, J. Org. Chem.,
2011, 76, 3498; (l) M. Khoobi, M. Alipour, S. Zareei,
F. Jafarpour and A. Shaee, Chem. Commun., 2012, 48,
¨
2985; (m) Z. He, S. Kirchberg, R. Frohlich and A. Studer,
Angew. Chem., Int. Ed., 2012, 51, 3699; (n) L. Zhang,
C. Dong, C. Ding, J. Chen, W. Tang, H. Li, L. Xu and
J. Xiao, Adv. Synth. Catal., 2013, 355, 1570; (o) L. Meng,
C. Liu, W. Zhang, C. Zhou and A. Lei, Chem. Commun.,
2014, 50, 1110; (p) J. Zheng, L. Huang, C. Huang, W. Wu
and H. Jiang, J. Org. Chem., 2015, 80, 1235.
9 For reviews, see: (a) J. Le Bras and J. Muzart, Chem. Rev., 12 A. Inoue, H. Shinokubo and K. Oshima, J. Am. Chem. Soc.,
2011, 111, 1170; (b) C. Jia, T. Kitamura and Y. Fujiwara, 2003, 125, 1484.
Acc. Chem. Res., 2001, 34, 633; (c) I. Moritani and 13 (a) K. Garves, J. Org. Chem., 1970, 35, 3273; (b) G.-W. Wang
Y. Fujiwara, Synthesis, 1973, 524. For recent examples, see: and T. Miao, Chem.–Eur. J., 2011, 17, 5787.
(d) K. M. Engle, D.-H. Wang and J.-Q. Yu, Angew. Chem., 14 X. Zhou, J. Luo, J. Liu, S. Peng and G.-J. Deng, Org. Lett., 2011,
Int. Ed., 2010, 49, 6169; (e) Y. Lu, D.-H. Wang, K. M. Engle 13, 1432.
and J.-Q. Yu, J. Am. Chem. Soc., 2010, 132, 5916; (f) 15 M.-K. Zhu, J.-F. Zhao and T.-P. Loh, Org. Lett., 2011, 13, 6308.
K. M. Engle, D.-H. Wang and J.-Q. Yu, J. Am. Chem. Soc., 16 Y.-H. Su, Z. Wu and S.-K. Tian, Chem. Commun., 2013, 49,
2010, 132, 14137; (g) D.-H. Wang, K. M. Engle, B.-F. Shi
and J.-Q. Yu, Science, 2010, 327, 315; (h) M. Ye, G.-L. Gao 17 Y.-G. Zhang, X.-L. Liu, Z.-Y. He, X.-M. Li, H.-J. Kang and
and J.-Q. Yu, J. Am. Chem. Soc., 2011, 133, 6964; (i) S.-K. Tian, Chem.–Eur. J., 2014, 20, 2765.
T. Nishikata and B. H. Lipshutz, Org. Lett., 2010, 12, 1972; 18 (a) T. Taniguchi, A. Idota and H. Ishibashi, Org. Biomol.
6528.
(j) H.-X. Dai, A. F. Stepan, M. S. Plummer, Y.-H. Zhang and
J.-Q. Yu, J. Am. Chem. Soc., 2011, 133, 7222; (k) C. Huang,
B. Chattopadhyay and V. Gevorgyan, J. Am. Chem. Soc.,
2011, 133, 12406; (l) S. Cui, L. Wojtas and J. C. Antilla, Org.
Lett., 2011, 13, 5040; (m) M. Yu, Z. Liang, Y. Wang and
Y. Zhang, J. Org. Chem., 2011, 76, 4987; (n) X. Liu and
Chem., 2011, 9, 3151; (b) X. Li, X. Xu and C. Zhou, Chem.
Commun., 2012, 48, 12240; (c) F.-L. Yang, X.-T. Ma and
S.-K. Tian, Chem.–Eur. J., 2012, 18, 1582; (d) R. Singh,
D. S. Raghuvanshi and K. N. Singh, Org. Lett., 2013, 15,
4202; (e) F.-L. Yang and S.-K. Tian, Angew. Chem., Int. Ed.,
2013, 52, 4929; (f) N. Singh, R. Singh, D. S. Raghuvanshi
and K. N. Singh, Org. Lett., 2013, 15, 5874; (g) W. Wei,
C. Liu, D. Yang, J. Wen, J. You, Y. Suo and H. Wang, Chem.
Commun., 2013, 49, 10239; (h) X. Li, X. Xu, P. Hu, X. Xiao
and C. Zhou, J. Org. Chem., 2013, 78, 7343; (i) X. Li, X. Xu
and Y. Tang, Org. Biomol. Chem., 2013, 11, 1739; (j)
S.-R. Guo, W.-M. He, J.-N. Xiang and Y.-Q. Yuan, Chem.
Commun., 2014, 50, 8578; (k) T.-T. Wang, F.-X. Wang,
F.-L. Yang and S.-K. Tian, Chem. Commun., 2014, 50, 3802;
(l) F.-L. Yang, F.-X. Wang, T.-T. Wang, Y.-J. Wang and
S.-K. Tian, Chem. Commun., 2014, 50, 2111; (m) X. Kang,
R. Yan, G. Yu, X. Pang, X. Liu, X. Li and L. Xiang, J. Org.
Chem., 2014, 79, 10605; (n) X. Zhao, L. Zhang, T. Li, G. Liu,
H. Wang and K. Lu, Chem. Commun., 2014, 50, 13121; (o)
Y. Yang, L. Tang, S. Zhang, X. Guo, Z. Zha and Z. Wang,
Green Chem., 2014, 16, 4106; (p) Q. Tian, P. He and
C. Kuang, Org. Biomol. Chem., 2014, 12, 6349; (q) X. Li,
Y. Xu, W. Wu, C. Jiang, C. Qi and H. Jiang, Chem.–Eur. J.,
2014, 20, 7911; (r) S. Tang, Y. Wu, W. Liao, R. Bai, C. Liu
and A. Lei, Chem. Commun., 2014, 50, 4496; (s) X. Li,
X. Shi, M. Fang and X. Xu, J. Org. Chem., 2013, 78, 9499; (t)
W. Zhang, K. Li and B. Zhao, J. Chem. Res., 2014, 38, 269;
(u) J. Wang, C. Xu, S. Wei, B. Zhao and K. Cheng, Chin. J.
Org. Chem., 2014, 34, 767.
´
K. K. Hii, J. Org. Chem., 2011, 76, 8022; (o) A. Garcıa-Rubia,
´˜
´
´
M. A. Fernandez-Ibanez, R. G. Arrayas and J. C. Carretero,
´
Chem.–Eur. J., 2011, 17, 3567; (p) A. Garcıa-Rubia,
´
B. Urones, R. G. Arrayas and J. C. Carretero, Angew. Chem.,
Int. Ed., 2011, 50, 10927.
10 (a) A. G. Myers, D. Tanaka and M. R. Mannion, J. Am. Chem.
Soc., 2002, 124, 11250; (b) D. Tanaka and A. G. Myers, Org.
Lett., 2004, 6, 433; (c) D. Tanaka, S. P. Romeril and
A. G. Myers, J. Am. Chem. Soc., 2005, 127, 10323; (d) P. Hu,
J. Kan, W. Su and M. Hong, Org. Lett., 2009, 11, 2341; (e)
S.-L. Zhang, Y. Fu, R. Shang, Q.-X. Guo and L. Liu, J. Am.
Chem. Soc., 2010, 132, 638; (f) Z. Fu, S. Huang, W. Su and
M. Hong, Org. Lett., 2010, 12, 4992.
11 For selected references: (a) C. S. Cho and S. Uemura, J.
Organomet. Chem., 1994, 465, 85; (b) X. Du, M. Suguro,
K. Hirabayashi and A. Mori, Org. Lett., 2001, 3, 3313; (c)
Y. C. Jung, R. K. Mishra, C. H. Yoon and K. W. Jung, Org.
Lett., 2003, 5, 2231; (d) M. M. S. Andappan, P. Nilsson and
M. Larhed, Chem. Commun., 2004, 218; (e) K. S. Yoo,
C. H. Yoon and K. W. Jung, J. Am. Chem. Soc., 2006, 128,
16384; (f) J. Ruan, X. Li, O. Saidi and J. Xiao, J. Am. Chem.
¨
Soc., 2008, 130, 2424; (g) J. Limdh, J. Savmarker,
P. Nilsson, P. J. R. Sjçberg and M. Larhed, Chem.–Eur. J.,
2009, 15, 4630; (h) Y. Leng, F. Yang, K. Wei and Y. Wu, 19 (a) F.-L. Yang, X.-T. Ma and S.-K. Tian, Chem.–Eur. J., 2012,
Tetrahedron, 2010, 66, 1244; (i) E. W. Werner and
M. S. Sigman, J. Am. Chem. Soc., 2010, 132, 13981; (j)
Y. Liu, D. Li and C.-M. Park, Angew. Chem., Int. Ed., 2011,
50, 7333; (k) A. L. Gottumukkala, J. F. Teichert,
D. Heijneen, N. Eeisink, S. V. Dijk, C. Ferrer,
18, 1582; (b) B. Liu, J. Li, F. Song and J. You, Chem.–Eur. J.,
2012, 18, 10830; (c) X. Yu, X. Li and B. Wan, Org. Biomol.
Chem., 2012, 10, 7479; (d) O. Y. Yuen, C. M. So,
W. T. Wong and F. Y. Kwong, Synlett, 2012, 23, 2714; (e)
W. Chen, H. Chen, F. Xiao and G.-J. Deng, Org. Biomol.
27588 | RSC Adv., 2016, 6, 27584–27589
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View Article Online
Paper
Chem., 2013, 11, 4295; (f) W. Zhang, B. Zhao and K. Li, J.
RSC Advances
2002, 4, 4179; (c) B. A. Steinhoff, S. R. Fix and S. S. Stahl, J.
Am. Chem. Soc., 2002, 124, 766; (d) B. A. Steinhoff,
L. A. Guzei and S. S. Stahl, J. Am. Chem. Soc., 2004, 126,
11268, and reference therein.
Chem. Res., 2013, 37, 674; (g) H. Miao, F. Wang, S. Zhou,
G. Zhang and Y. Li, Org. Biomol. Chem., 2015, 13, 4647; (h)
S. Zhong, C. Sun, S. Dou and W. Liu, RSC Adv., 2015, 5,
27029.
21 Only poor to fair yields could be observed when non-
terminal and aliphatic alkenes were used as substrates in
this oxidative Heck reaction. The isolation of the desired
products from the complicated reaction mixtures
containing the homo-coupling by-products and the
regioisomers were unsuccessful.
20 For oxidation of reduced palladium by molecular oxygen is
the rate limiting step for the Pd(OAc)2/DMSO system
catalyzed oxidative amination of olens, see: (a) S. R. Fix,
J. L. Brice and S. S. Stahl, Angew. Chem., Int. Ed., 2002, 41,
164; for Pd(OAc)2/pyridine catalyst for aerobic alcohol
oxidation, see: (b) B. A. Steinhoff and S. S. Stahl, Org. Lett.,
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