Supported palladium nanoparticles-catalyzed decarboxylative coupling approaches to aryl alkynes, indoles and pyrrolines synthesis

Article abstract of DOI:10.1039/c6ra12046f

The polystyrene supported palladium (Pd@PS) nanoparticles (NPs) catalyzed decarboxylative coupling (DC) of arylhalides and alkynyl carboxylic acids was developed for the synthesis of diaryl alkynes. Indole and 3-pyrroline heterocycles were also synthesized from 2-iodo anilines/amino benzocycloheptene bromide and alkynyl carboxylic acids, following a domino decarboxylative coupling-cyclization (DCC) approach under the same catalytic conditions. The combined anchoring and catalytic behaviour of Pd@PS makes the process favourable for the product formation.

Full text of DOI:10.1039/c6ra12046f

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ARTICLE
Supported Palladium Nanoparticles-Catalyzed Decarboxylative
Coupling Approaches for Aryl Alkynes, Indoles and Pyrrolines
Synthesis
Received 00th January 20xx,
Accepted 00th January 20xx
a,b
a,b,C
a,b
a,b
DOI: 10.1039/x0xx00000x
C. Bal Reddy, RichaBharti,
Sandeep Kumar, PralayDas*
www.rsc.org/
Polystyrene supported palladium (Pd@PS) nanoparticles (NPs) catalyzed decarboxylative coupling (DC) of arylhalides and
alkynyl carboxylic acids was developed for diaryl alkynes synthesis. Indole and 3-pyrroline heterocycles were also
synthesized from 2-iodo anilines/ amino benzocycloheptene bromide and alkynyl carboxylic acids following a domino
decarboxylative coupling-cyclization (DCC) approaches under the same catalytic condition. The combined anchoring and
catalytic behaviour of Pd@PS makes the process favourable for the product formation.
afforded by 5-endo cyclization of α-amino allenes prompted
9
by transition metal catalysts and base. In addition few multi-
Introduction
component reactions were also demonstrated by using
9
The decarboxylative couplings of alkynyl carboxylic acids have
been identified as a viable tool for C-C, C-heteroatom bond
e,9f
copper- and organo-catalytic conditions.
Most of the
1
reported methods for the synthesis of indoles and 3-pyrrolines
either performed in homogeneous catalytic condition or
required additional cyclizing agents. Recently the domino
decarboxylative coupling-cyclization has been reported for the
4a synthesis of substituted indoles was performed in CuBr/L-
Proline catalytic system which is only applicable for 2-
formation processes. Alkynyl carboxylic acids have emerged as
coupling partners in Sonogashira type reactions for the
2
synthesis of pharmaceutically potent diaryl motif rather than
terminal alkynes due to easy handling, high boiling point, and
3
high stablility. Since the development of first Pd
2
dba
3
/dppf
catalytic system for decarboxylative coupling of alkynyl
carboxylic acids with aryl halides, a number of protocols using
1
0
iodotrifluoro acetanilide substates.
4
b-4i
palladium complexes
Xantphos, Pd(OAc)
Palladacycle/Xphos, etc.) and copper
CuI/PPh and CuI/Fe(acac) ) catalyst were developed. The only
heterogeneous catalyst reported for
decarboxylativeSonogashira coupling is Pd-CNT (carbon nano
(Pd
2
dba
3
/dppb, Pd
2
dba
3
CHCl
Cl
(CuI/1,10-Phen,
3
/PPh
3
or
Previous work
R
2
/XPhos,
Pd(PPh
3
)
2
2
/dppb,
5
I
Method A
Method B
R
3
3
cyclizing agent
N
1)
R
NHR
This work
1
NHR
1
1
R /H
Pd or Cu
4
g
tube).
Although, decarboxylativeSonogashira coupling
I
R
1
reactions under homogeneous catalytic condition are well
documented but less attention has been paid to apply the
decarboxylative coupling strategy for the synthesis of
functionalized indoles and 3-pyrrolines, an important scaffold
N
R
NHR'
R
Pd@PS
1
COOH
R'/H
R
NHR
Br
NR
DBU, DMF
110 °C
6
of natural and pharmaceutical products. Reported protocols
R
1
—
—
Step economical process
Devoid of cyclising agent
to access 2-substituted indoles includes, i) cycloisomerization
of 2-alkynyl anilines using transition metal catalysts, lewis
7
acids, and strong bases (Scheme 1, Method A) and ii) domino
— Shorter reaction time
— Recyclable catalyst
coupling-cyclization of protected 2-haloanilines and terminal
Scheme 1. Background of the reaction
alkynes under copper- and palladium catalyzed conditions
8
Scheme 1, Method B). Moreover 3-pyrrolines can be
(
Therefore, the development of heterogeneous palladium
catalyzed novel and reliable decarboxylative coupling strategy
for the synthesis of di-aryl alkynes and five member nitrogen
heterocycles under ligand free conditions is highly desirable.
As a part of our continuous research on the development
of supported transition metal nanoparticles as a catalyst and
a.
Natural Product Chemistry and Process Development Division, CSIR-Institute of
Himalayan Bioresource Technology, Palampur-176061, H. P., India. Fax: (+91)-
1
894-230-433; e-mail: pdas@ihbt.res.in; pdas_nbu@yahoo.com.
b.
c.
Academy of Scientific and Innovative Research (AcSIR), New Delhi, India..
Scheme 5 work contributed by R.B.
Electronic Supplementary Information (ESI) available: [Experimental details and
Spectral data]. See DOI: 10.1039/x0xx00000x
11
its applications in various organic transformations, herein
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bases (Table 1, entries 1-6) and solvents (Table 1, entries 7-13)
screened, DBU as base and DMF as solvent gave the best
result. Gratifyingly, the Pd@PS catalyst was found more active
than the commercially available Pd/C (Table 1, entries 14). The
optimum condition was found to be: Pd@PS (3 mol%), DBU (3
o
equiv) in DMF at 110 C for 12 h giving 78% of desired product.
Under the optimized condition phenyl acetylene was found to
be less active for the coupling reaction (Table 1, entry 15)
therefore, oxidative adduct (Ar-Pd-halide) may be responsible
for the decarboxylation of palladium carboxylate to form aryl
alkynyl palladium and further reductive elimination gave the
desired product.
a
Table 1. Optimization of Reaction Conditions
I
catalyst, base
+
COOH
MeO
solvent
°
1
10 C, 12 h
3a
1
a
2a
OMe
yield (%)b
22
entry
1
catalyst (mol %)
Pd@PS (3)
base
solvent
DMF
K2CO3
2
3
4
5
Pd@PS (3)
Pd@PS (3)
Pd@PS (3)
Pd@PS (3)
Pd@PS (2)
Pd@PS (3)
Pd@PS (3)
Et N
DMF
DMF
DMF
DMF
DMF
DMF
DMF
nr
14
3
Fig 1. (a) SEM, (b) EDS, (c) TEM at 20 nm scale, (d) TEM at 5 nm scale, (e) Particle size
distribution histrogram as calculated from (d), (f) HRTEM image showing lattice fringe
spacing, (g), (h) FFT of selected region showing icosahydral and cubic structure of
planes, (i) SAED diffraction pattern.
3 4
K PO
DABCO
KOtBu
DBU
16
37
6
7
65
DBU
89 (78)
45
we present Pd@PS NPs catalyzed decarboxylative coupling for
the synthesis of di-aryl alkynes and domino DCC to synthesize
8c
DBU
functionalized
indoles.
Further
structurally
similar
9
Pd@PS (3)
Pd@PS (3)
Pd@PS (3)
Pd@PS (3)
DBU
DBU
DBU
DBU
1,4ꢀdioxane
toluene
6
1
2
10
nr
10
20
antidepressant molecules, amino benzocycloheptene vinyl
bromides were also converted to corresponding new class of
11
CH CN
3
12
DMA
3-pyrrolines by domino decarboxylative coupling-5-exo
13
Pd@PS (3)
Pd/C (3)
DBU
DBU
DBU
DMSO
DMF
56
10
34
cyclization reaction with phenylpropiolic acid under the same
catalytic conditions.
1
4
1
5d
Pd@PS (3)
DMF
The Pd@PS NPs were prepared by following our earlier
reported
reduction
deposition
method
(Electronic
Supplementary Information ESI). The developed Pd@PS
a
Reaction conditions: 1a (0.42 mmol), 2a (0.51 mmol), base (3 equiv), catalyst (3
b
c
catalyst was further analyzed for its morphology and mol %) and DMF (2 mL) at 110 ºC. GC-MS yield; isolated yield in parenthesis. At
crystalline structure by scanning electron microscopy (SEM), 90 C. 2a = phenyl acetylene.
o
d
transmission electron microscopy (TEM) and selected area
electron diffraction (SAED) studies. The particles at surface The scope of DC reaction was investigated by using different
were analyzed by SEM and SEM-EDS (energy dispersive aryl iodides and aryl bromides with alkynyl carboxylic acids
spectra) that revealed the presence of palladium NPs at the under the optimized reaction conditions (Scheme 2). Electron-
surface of PS (Fig. 1a, 1b). The low field TEM image of Pd@PS rich and neutral aryl iodides successfully coupled with
further confirmed the impregnation of palladium NPs of size in phenylpropiolic acid in good yields (70 and 66%) of 3b and 3c
between 1-5 nm with largest average number in range 1-3 nm Moreover base sensitive and electron withdrawing groups (e.g,
Fig. 1c-e). The high resolution TEM (HRTEM) image of Pd@PS CO CH , COCH , CHO, CN, CF and Cl) were well tolerated
.
(
2
3
3
3
showed interplanar distance of 0.22 nm corresponding to under the reaction conditions and furnished the corresponding
111) plane and 0.19 nm corresponding to (200) planes of face internal alkynes 3d
3i in 58-96% yields. In addition, ortho
(
-
centered cubic arrangement of palladium (Fig. 1f). The substituted aryl iodides such as 2-iodoaniline, 2-iodo
heterogeneity of Pd@PS catalyst was further confirmed by acetanilide smoothly yielded desired products 3j and 3k in 74%
Hg(0) poisoning and hot filtration tests (Fig. 3) that revealed and 76% respectively. Alcohol substituted aryl halide such as 3-
the catalysis took place in a truly heterogeneous manner as iodobenzylalcohol was allowed to react with phenylpropiolic
the negligible leaching of palladium was detected by ICP-AES acid under the optimized reaction conditions, di-aryl alkyne 3l
analysis after the fifth reaction cycle (Fig. 2).
was formed in 86% yield. Heterocyclic halide such as 2-
We started our investigation using 4-iodo anisole and iodothiophene also found to be compatible with the employed
phenyl propiolic acid as model substrates. Among different
2
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a
Scheme 2. Substrate Scope of Pd@PS Catalyzed Decarboxylative Coupling
5b and 5c in 77% and 72% yields respectively which indicates
that the present protocol may have a broad potential for
constructing extended π-electron systems.
a
Scheme 3. Pd@PS Catalyzed Decarboxylative Coupling of Diiodoarenes
a
Reaction conditions: 4 (1 equiv.), 2 (1.2 equiv.), DBU (3 equiv.), Pd@PS (3 mol%), DMF
(
2 mL), at 110 ºC for 12 h; all are isolated yields.
We next attempted the Pd@PS catalyzed decarboxylative
coupling of 2-iodo-N-tosylanilines with various alkynyl
carboxylic acids (Scheme 4). We were delighted to observe the
synthesis of N-tosylated indoles without any need of external
cyclizing agent. The mechanistic investigation reveals that
palladium catalyst as well as DBU assisted the cyclization
reaction (ESI). The various substituents on 2-iodo-N-
tosylanilines had no effect as all reacted smoothly with
a
Reaction conditions: aryl halide 1 (1 equiv.), alkynyl carboxylic acid 2 (1.2 equiv.), DBU phenylpropiolic acid to give approximately same yield of
3 equiv.), Pd@PS (3 mol%), DMF (2 mL), at 110 ºC for 12 h; all are isolated yields.
(
b
corresponding
products
7a-7c
.
Similarly,
3-(4-
c
Reactions of aryl bromide. Reactions of aryl chlorides
chlorophenyl)propiolic acid and but-2-ynoic acid were also
found effective coupling partners yielding the desired products
reaction conditions, producing 3m in 76% yield. Poly
substituted aromatic iodide also reacted smoothly and
produced 3n in 82% yield. It is gratifying to say that the
reaction conditions were compatible to a variety of propiolic
7d-7f in good yields. Surprisingly, N-(2-iodophenyl)methane
sulfonamide, 2-iodotriflouroacetanilide, 2,2,2-trifluoro-1-(2-
iodo-4-methylphenyl)ethanone reacts with phenylpropiolic
acid gave indole 7g and 7h in one pot coupling cyclization and
acids bearing electron donating and withdrawing deprotection approaches.
functionalities in the coupling reaction with different aryl
Scheme 4. Pd@PS Catalyzed One-pot Decarboxylative Coupling-Cyclization to
access Functionalized Indoles
iodides and gave the coupled products 3o-p and 3s in high
yields. To our surprise the reaction of 4-iodoanisole with 2-
butynoic acid gave the corresponding internal alkyne 3r in 58%
yield. In addition the decarboxylative coupling of arylbromides
were also studied under the same catalytic conditions and the
corresponding products 3d, 3e, 3t and 3u were attained in
moderate yields. Finally the decarboxylative coupling of aryl
chlorides with phenyl propiolic acid were also attained to get
the coupled products 3e and 3t in lower isolated yields and the
major quantity of starting material was recovered.
a
The reactions of diiodobenzenes with phenylpropiolic acid
were also carried out under the aforementioned reaction
conditions (Scheme 3). Intriguingly, the reaction of 1,2-
diiodobenzene with phenylpropiolic acid gave the
corresponding bis-coupled product 5a in 94% yield. Similarly
the coupling reaction of 1,3- and 1,4-diiodobenzenes with
phenylpropiolic acid afforded the desired bis coupled products
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a
Reaction conditions: 6 (1 equiv.), 2 (1.2 equiv.), DBU (3 equiv.), Pd@PS (3 mol%),
The recyclability of Pd@PS catalyst was investigated in the
decarboxylative coupling of 4-iodoanisole with phenylpropiolic
acid under standard reaction condition. After completion of
the reaction the catalyst was recovered by simple filtration and
washed with water, acetone and dried over reduced pressure
and reused. It was found that the catalyst was recycled upto 5
times without significant loss of activity (Fig. 2). ICP-AES
analysis was used to detect the palladium leaching into the
resulting reaction solution and only <1 ppm of palladium was
detected (ESI).
º
b
DMF (2 mL), at 110 C for 12 h; all are isolated yields. reaction with N-(2-
c
iodophenyl)methanesulfonamide. reaction when Ts replace by COCF
3
The methodology was further extended for the synthesis of
bioactive,
3-pyrroline
derivatives
cyclization
by
tandem
amino
decarboxylativecoupling-5-exo
of
benzocycloheptene bromides with phenylpropiolic acid
1
2
(Scheme 5).
Different Benzyl substituted amino
benzocycloheptene bromides were easily coupled and cyclized
to furnish new class of 3-pyrroline compounds 9a
-9d in 71-52
%
yields. Naphthyl-methyl substituted
amino
benzocycloheptenebromide also coupled to get the desired
pyrroline 9e in 73%. Interestingly, aryl substituted amino
benzocycloheptene bromide also participated in the similar
reaction with phenyl propiolic acid to produce corresponding
3-pyroline product 9f in considerably good yield 60%. Alkyl
amine substituted amino benzocycloheptene bromides were
also found to be reactive and gave the corresponding products
9g and 9h in good yields.
Scheme 5. Pd@PS Catalyzed One-pot Decarboxylative Coupling-5-exo Cyclization to
Fig. 2 Recyclability experiment of Pd@PS catalyst
a
access new class of 3-Pyrrolines
Mercury test
NHR
Br
R
N
Mercury drop test was operated to evaluate the heterogeneity
of the catalyst as well as catalytically active species under the
reaction condition. The addition of Hg(0) to the
heterogeneously catalysed reactions is known to inhibit the
activity of the catalyst due to amalgam formation on the
catalytic surface. In contrast, Hg(0) does not inhibit the
catalytic activity of homogeneous palladium catalysts. When a
drop of mercury was added to the reaction mixture of 4-
iodoanisole and phenylpropiolic acid under optimized reaction
conditions traces of product was observed, whereas mercury
free experiment give highest yield of the desired product
indicating that the mercury leads to amalgamation of the
catalytic surface of the heterogeneous catalyst (Pd@PS) which
further confirms that the catalytic active species under the
reaction condition are Pd(0) and the reaction occurred in a
truly heterogeneous manner.
Pd@PS (3mol%)
DBU (3 equiv)
Ph
+
Ph
COOH
MeO
DMF, 110 °
12 h
C
Me
Me
Me Me
Me
8
2
Me 9
Me
MeO
MeO
N
N
N
Ph
Ph
Ph
Me
Me
Me
Me Me
Me
Me
Me
Me
9
a 71%
9b 61%
9c 76%
OMe
N
N
N
Ph
Me
Ph
Ph
Hot filtration test
Me
Me
Me
Me Me
Me
Me
9e 73%
Me
The reaction of 4-iodoanisole with phenylpropiolic acid was
carried out under the standard reaction condition, after 2h
9
d 52%
9f 60%
(
the yield of the product was 30%) the solid catalyst was
N
filtered out and the reaction continued for 12h no further
increase in the yield of the product was observed indicating
the absence of palladium (ІІ) species in the solution and the
decarboxylation reaction was truly heterogeneous (Fig. 3).
N
Ph
Ph
Me
Me
Me
Me
Me
Me
9
g 65%
9h 72%
a
Reaction conditions: 8 (1 equiv.), 2 (1.2 equiv.), DBU (3 equiv.), Pd@PS (3 mol%),
o
DMF (2 mL), at 110 C for 12 h; all are isolated yields.
Recyclability experiments
4
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5
6
(a) J. Mao, M. Wu, G. Xie and S. Ji, Adv. Synth. Catal., 2009,
51, 2101; (b) X. Qu, T. Li, P. Sun, Y. Zhu, H. Yang and J. Mao.
Org. Biomol. Chem., 2011, , 6938; (c) D. Zhao, C. Gao, X. Su,
Y. He, J. You and Y. Xue, Chem. Commun., 2010, 46, 9049; (d)
T. Li, P. Sun, H. Yang, Y. Zhu, H. Yan, L. Lu and J. Mao,
Tetrahedron Lett., 2012, 68, 6413.
(a) S. Cacchi and G. Fabrizi, Chem. Rev., 2005, 105, 2873; (b)
M. Somei and F. Yamada, Nat. Prod. Rep., 2004, 21, 278; (c)
W. Shi, S. L. Marcus and T. L. Lowary, Bio org. Med. Chem.,
3
9
2
(
2
011, 19, 603; (d) D. O'Hagen, Nat. Prod. Rep., 2000, 17, 435;
e) W. K. Anderson and A. S. Milowsky, J. Med. Chem., 1986,
, 2241; (f) G. R. Petti, Y. Kamano, C. Dufresne, R. L. Cerny,
9
Fig. 3 Hot filtration test for decarboxylative coupling reaction
C. L. Herald and J. M. Schmidt, J. Org. Chem., 1989, 54, 6005.
(a) K. Hiroya, S. Itoh and T. Sakamoto, J. Org. Chem., 2004,
69, 1126; (b) Y. Yin, W. Ma, Z. Chai and G. Zhao, J. Org.
7
Conclusions
Chem., 2007, 72, 5731; (c) N. Sakai, K. Annaka, A. Fujita, A.
Sato and T. Konakahra, J. Org. Chem., 2008, 73, 4160; (d) X.
Li, A. R. Chianese, T. Vogel and R. H. Crabtree, Org. Lett.,
In conclusion, Pd@PS NPs was found to be highly active
catalyst for the decarboxylative coupling of arylhalides and
alkynyl carboxylic acids to produce diaryl alkynes. The ability of
the catalyst has also been exploited in domino decarboxylative
coupling-cyclization (DCC) reaction for indoles and new classes
of pyrrolines synthesis. The benefits of this process such as
simple operation, recyclability, vast selectivity profile and
milder reaction conditions produce an alternative
decarboxylative coupling strategy in comparison with the
existing procedures.
2005,
Nakamura, Org. Lett., 2006,
7, 5437; (e) M. Nakamura,L.Ilies, S.Otsubo and E.
8, 2803; (f) J. McNulty and K.
Keskar, Eur. J. Org. Chem., 2014, 1622; (g) R. Sanz, V. Cuilarte
and M. P. Castroviejo, Synlett., 2008, 3006 and references
cited therein.
8
9
(a) F. Liu and D. Ma, J. Org. Chem., 2007, 72, 4844; (b) R.
Wang, S. Mo, Y. Lu and Z. Shen, Adv. Synth. Catal., 2011, 353,
13; (c) L. Djakovitch, V. Dufaud and R. Zaidi, Adv. Synth.
7
Catal., 2006, 248, 715.
(a) R. K. Dieter and H. Yu, Org. Lett., 2001,
3, 3855; (b) N.
Morita and N. Krause, Org. Lett., 2004,
and S. Matsubara, Org. Lett., 2011, 13, 4676; (d) H. Ohno, Y.
Kodoh, N. Fujii and T. Tanaka, Org. Lett., 2006, , 947; (e) S.
L. Cui, J. Wang and Y. G. Wang, Org. Lett., 2007, , 5023; (f)
6, 4121; (c) M. Sai
8
Acknowledgements
9
A. Desmarchelier, V. Coeffard, X. Moreau and C. Greck,
Chem. Eur. J., 2012, 18, 13222.
Authors are grateful to the Director, CSIR-IHBT for providing
necessary facilities during the course of the work. We thank 10 T. Ponpandian and S. Muthusubramanian, Tetrahedron Lett.,
Dr. G. Saini, AIRF, JNU-New Delhi, India for the TEM and
Biotechnology Division, CSIR-IHBT, for SEM and EDS analysis;
R.B thanks CSIR, New Delhi, for financial support as part of XII
Five Year Plan programme under the title ORIGIN (CSC-0108).
C.BR, S.K thank UGC, New Delhi for awarding fellowship.
2012, 53, 4248
1
1 (a) P. Das, D. Sharma, A. K. Shil and A. Kumari, Tetrahedron
Lett., 2011, 52, 1176; (b) N. R. Guha, C. Bal Reddy, N.
Aggarwal, D. Sharma, A. K. Shil, Bandna and P. Das, Adv.
Synth. Catal., 2012, 354, 2911; (c) A. K. Shil and P. Das,
Green Chem., 2013, 15
Bhattacharjee and P. Das, Catal. Sci. Technol., 2015,
e) A. K. Shil, S. Kumar, C. Bal Reddy, S. Dadwal, V. Thakur
,
3421; (d) N. R. Guha, D.
5
, 2575;
(
and P. Das. Org. Lett., 2015, 17, 5352; (f) N. R. Guha, S.
Sharma, D. Bhattacherjee, V. Thakur, R. Bharti, C. Bal Reddy
and P. Das, Green Chem., 2016, 18, 1206.
Notes and references
1
2
3
4
(a) K. Park and S. Lee, RSC Adv., 2013,
J. Mao, H. Yan, Y. Zheng and G. Zhang, J. Org. Chem., 2015
0, 7652.
(a) J. Boukouvalas, S. Cote, B. Ndzi, Tetrahedron Lett., 2007,
, 105; (b) D. Falcone, J. Li, A. Kale and G. B. Jones, Bioorg.
Med. Chem. Lett., 2008, 18, 934.
(a) K. Park, T. Palani, A. Pyo and S. Lee, Tetrahedron Lett.,
2012, 53, 733; (b) K. Park, J.-M.. You, S. Jeon and S. Lee, Eur.
J. Org. Chem., 2013, 1973.
(a) J. Moon, M. Jeong, H. Nam, J. Ju, J. H. Moon, H. M. Jung
and S. Lee, Org. Lett., 2008, 10, 945; (b) J. Moon, M. Jang and
S. Lee, J. Org. Chem., 2009,74, 1403; (c) H. Kim and P. H. Lee,
Adv. Synth. Catal., 2009, 351, 2827; (d) W. -W. Zhang, X. –G.
Zhang and J. -H. Li, J. Org. Chem., 2010, 75, 5259; (e) K. Park,
G. Bae, J. Moon, J. Choe, K. H. Song and S. Lee, J. Org. Chem,.
3, 14165; (b) G. Rong,
1
2 (a) A. Chaudhary, P. Das, A. Mishra, P. Kaur, B. Singh and R.
,
K
.
Goel, Mol. Divers., 2012, 16, 357; (b) A. Chaudhary and P.
Das, Current Organic Chemistry., 2015, 19, 179.
8
4
8
2
010, 75, 6244; (f) S. Tartaggia, O. D. Lucchi and L. J.
Goossen, Eur. J. Org. Chem., 2012, 1431; (g) A. Pyo, J. D. Kim,
H. C. Choi and S. Lee, J. Organomet. Chem., 2013, 724, 271;
(h) P. V. Reddy, P. Srinivas, M. Annapurna, S. Bhargava, J.
Wagler, N. Mirzadeh and M. L. Kantam, Adv. Synth. Catal.,
2
2
013, 355, 705; (i) X. Li, F. Yang and Y. Wu, J. Org. Chem.,
013, 78, 4543.
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RSC Advances
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DOI: 10.1039/C6RA12046F
Supported Palladium Nanoparticle-Catalyzed Decarboxylative Coupling
Approaches for Aryl Alkynes, Indoles and Pyrrolines Synthesis
*
C. Bal Reddy, Richa Bharti, Sandeep Kumar, Pralay Das
Graphical Abstract: