Efficient Microwave-Assisted Synthesis of Sonogashira-Coupled Perylene Monoimide Derivatives: Impact of Electron-Donating Groups on Optoelectronic Properties

Article abstract of DOI:10.1002/ejoc.201701310

An efficient microwave-assisted Sonogashira-coupling protocol for the synthesis of peri-functionalized perylene monoimide dye derivatives was developed. This method was found to be significantly faster than the conventional coupling method and provided pr

Full text of DOI:10.1002/ejoc.201701310

A Journal of
Accepted Article
Title: An Efficient Microwave-assisted Synthesis of Sonogashira-
coupled PMI Derivatives: Impact of Electron Donating Groups on
Optoelectronic Properties
Authors: Apurba Lal Koner, Vikas Sharma, Falguni Chandra, and
Dhananjaya Sahoo
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To be cited as: Eur. J. Org. Chem. 10.1002/ejoc.201701310
Link to VoR: http://dx.doi.org/10.1002/ejoc.201701310
Supported by

10.1002/ejoc.201701310
European Journal of Organic Chemistry
COMMUNICATION
An Efficient Microwave-assisted Synthesis of Sonogashira-
coupled PMI Derivatives: Impact of Electron Donating Groups on
Optoelectronic Properties
Vikas Sharma, Falguni Chandra, Dhananjaya Sahoo* and Apurba L. Koner*[a]
Abstract: An efficient microwave-assisted Sonogashira-coupling
protocol for peri-functionalised perylenemonoimide dye derivative is
presented. This method is significantly faster than conventional
coupling method providing a moderate to good yield and interesting
optoelectronic properties. The electronic communication between
electron-rich aryl and poly aryl groups with the perylene core via
C≡C bonds is investigated.
shows only 7 nm red shift, further supports the small effects due
to bay functionalization (C-1 and C-6).[9]
Bay position
Fluoropore
A
R'
R"
R'"
H
H
H
R'
O
N
O
11 12
1
2
5
O
N
B
H
H
OAr
10
9
Peri position
C
D
OAr
CN
OAr
CN
OAr
CN
R"'
Rylene dyes such as perylenemonoimide (PMI), perylene bis-
imides (PDI), terylenemonoimides (TMI), Terylene di-imides
(TDI) have found wide spread applications ranging from
industrial pigments to components of molecular photonic
devices.[1] PMI dyes have drawn attention due to their unique
properties such as high fluorescence quantum yield,[2] high
stability[3] and implemented as a suitable candidate for energy
transfer, photocatalysis and nonfullerene-based organic solar-
cells.[4] The synthetic chemistry of PMI dyes has developed
rapidly over the past few decades, by converting commercially
available perylene-3,4,9,10-tetracarboxylic dianhydride into
PMI.[3]
O
7
8
6
R"
(Me)3C
E
F
OAr'
OAr
OAr"
OAr
CN
Py
O
OAr =
C(Me)3
O
OAr' =
Py =
C(Me)3
N
OAr'' =
O
R
PMI (6')
Figure 1 Structural representation of different PMI dyes derivatives containing
functional group at bay and peri position
Tomizaki et al.[7] reported the functionalized PMI F where the
peri position was substituted by pyrrolidino group and the bay
!"#
The primary challenge in working with perylene dyes is
positions were with the OAr groups (F, Fig. 1). The ꢀ
shows
!"#
associated with their intrinsic low solubility. Lately, 2,5-ditertbutyl, a red shift of 95 nm in comparison to PMI A and 65 nm in
!"#
2,6-diisopropyl phenyl groups, or alkyl groups were incorporated
at the N-atom of the imides moiety to tackle the solubility
problem without affecting the optical properties.[1b, 4b, 5] Variation
of their imide substitution can influence the solid-state packing
but impart a negligible effect on solution properties because of
the nodes present at the imide nitrogen.[1b, 4b, 5] The bay and peri
position of PMI A was functionalized to achieve further solubility
(Figure 1) as well as a change in the optical properties.[5b, c, 6]
comparison to the fluorophore C. Such a large shift in the ꢀ
is
!"#
due to the conjugation of electron pair on the N-atom of the
pyrrolidino group with PMI core. Considering a dramatic change
upon peri-functionalization of PMI, we came to the hypothesis
that introduction of π-conjugation may extend electronic
communication further leading to interesting optical properties.
As part of our continuing studies on the optoelectronic properties
of PMI derivatives, we employed the standard Sonogashira-
[5c, 6]
[4a, 5b, 7]
Müllen
and Lindsey
have developed methods for the
coupling methods (reaction time 18 h) to synthesize the PMI
b]
halogenations at bay and peri-position of PMI and subsequent
substitution of the halogenated PMI dyes. Literature studies[7]
show that functional groups at the node of PMI have no effect on
its optical properties, but that the presence of an OAr group at
derivatives.[5a,
We
introduced
microwave-assisted
Sonogashira-coupling reaction keeping in mind its increasing
interest for reduced reaction times.[10] Despite these benefits,
microwave-assisted synthesis remains underutilized for the
chemical manipulation of rylene dyes.[10d, 11]
Herein, we report a microwave-assisted synthesis of 9-bromo
PMI 2, a library of Sonogashira-coupled peri-functionalized PMI
derivatives 3, and 6a-i, (Scheme 1) and alkynyl coupled
electron-rich aryl and poly aryl compounds 8c-g precursor for
7c-g (see SI) at reaction rates significantly faster than the
conventional method. The optoelectronic properties of the
synthesized peri-functionalized PMIs 6a-i were extensively
studied and compared with PMI derivative 6' (see Figure 1)
prepared via Suzuki coupling.[12]
the peri position [PMI(OAr) B, Fig. 1] shifts the absorption
!"#
maximum ( ꢀ
) to
a
longer wavelength, compared to
!"#
unsubstituted PMI A.[7] However, by introducing one OAr shows
a shift of 26 nm in toluene where as three OAr groups at bay
and peri position (1, 6, and 9- position) of the PMI [PMI(OAr)3 C,
!"#
Fig. 1] the ꢀ
is shifted by 30 nm, suggesting a small change
!"#
due to the bay functionalization.[1a, Similarly, when the bay
8]
region of the fluorophore D is replaced with an electron
!"#
withdrawing CN groups ꢀ
of the resulting fluorophore E
!"#
With an aim toward the rapid synthesis of perylene derivatives
with novel properties, we performed bromination at the peri-
position of PMI by refluxing PMI 1 with Br2 in DCM for 2-3 h to
obtain the 9-bromo PMI 2 in 80-90 % yield.[4f, 5b, 13] Interestingly,
the bromination reaction was carried out in DCM at 40 °C for 5
minutes by using microwave-assisted irradiation and 9-bromo
PMI 2 was isolated in 90% yield. The brominated product 2 was
coupled with the TIPS acetylene in a microwave reactor at 75 °C
[a]
Mr. V. Sharma, Mr. F. Chandra, Dr. D. Sahoo, and Dr. A. L. Koner
Department
Indian Institute
of
Science
Chemistry
Research
of
Education
and
Bhopal By-pass Road, Bhauri, Bhopal-462066,MP, India
E-mail: chem.dsahoo@gmail.com, akoner@iiserb.ac.in (homepage:
http://home.iiserb.ac.in/~akoner/index.html)
Supporting information data are given via a link at the end of the
document.
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10.1002/ejoc.201701310
European Journal of Organic Chemistry
COMMUNICATION
for 25 min against the traditional procedure. The TIPS group of
THF) at room temperature for 20 min to obtain the 9-ethyne PMI
4 in 80-90 % yields. The 9-arylakynyl-coupled PMI 6 can be
synthesized by two possible routes via (A) by coupling the 9-
the PMI derivative 3 was further treated with TBAF (1.0 M in
ethyne PMI 4 with aryl halides 5, (B) by coupling PMI-Br 2 with
the
different
arylalkynes
7
(scheme
1).
O
N
O
O
N
O
O
N
O
b
a
Br
R
1
2
R = TIPS, 3
O
N
O
Ar
H
Ar
X
c
7
f
5
R = H, 4
Route A
d/e
Ar
h
Route B
6
5/7
a
b
c
d
e
f
g
i
Ar =
BocN
N
MeO
N
S
S
X =
Br
Br
Br
Br
Br
I
I
I
I
a) Br2, DCM, 40 °C, 5 min, µ-wave; b) TIPS acetylene, Pd2(dba)3, P(o-tolyl)3, toluene, Et3N, 75 °C, 25 min, µ-wave; c) nBu4NF, THF, rt, 20 min; d) Pd2(dba)3, P(o-
tolyl)3, toluene, Et3N, 40-55 °C, 5-10 min, µ-wave (synthesis of compound 6a-e); PdCl2(PPh3)2, CuI, THF, piperidine, 40 °C, 5 min, µ-wave (for compounds 6f-i); e)
Pd2(dba)3, P(o-tolyl)3, toluene, Et3N, 65 °C, 18 h (synthesis of compounds 6a-e), PdCl2(PPh3)2, CuI, THF, piperidine, rt, 18 h (for 6f-i); f) Pd2(dba)3, P(o-tolyl)3,
toluene, Et3N, 55 °C, 5-10 min, µ-wave (compounds 6a-g)
Scheme 1 Synthesis details of the peri-functionalized PMI derivatives
We have carried out the synthesis of compound 6 by following
aIsolated yield (%); bFor route A, conventional synthesis, the reaction
the route A using the Sonogashira coupling by traditional as well
as microwave-assisted irradiation. By using the microwave-
assisted protocol, the compounds 6a-i were synthesized with a
comparable yield with the traditional route and the reaction time
was dramatically reduced from 18 h to 5-10 min (scheme 1). By
following the route B, peri-functionalized PMI derivatives 6a-6g
were synthesized by using the microwave-assisted protocol with
good to excellent yield and it seems to be an efficient route
(scheme 1, table 1).
temperature was 65 °C, in toluene/TEA and reaction time was 18 h; cEven
after several attempts the coupling partner free acetylene 7h & 7i were not
isolated.
0.60
1
1
(a)
(b)
6a
6b
6c
6e
6f
0.4
0.2
0.0
'
6
6a
0.30
0.00
6h
Table 1 Reaction temperature, duration and % of yields for the synthesis of
PMI derivatives 6a-i
400
450
500
550
600
410
460
510
560
Wavelength/ nm
Wavelength/ nm
PMI
Route A
Traditional
yielda,b
Route B
Figure 2. Absorption spectra of (a) 1, 6', 6a; and (b) 1 with representative PMI
derivatives in toluene
MW assisted
t
MW assisted
yielda
yielda
T
T
/°C
t
/°C
/min
10
10
10
5
/min
The compounds 6h and 6i were not synthesized by route B as
we failed to isolate the free acetylene 7h and 7i in several
attempts due to their low-boiling point. The synthesis of free
acetylenes 7c-g was reported in the SI. The library of different
peri-functionalized PMI derivatives 6a-i showed good solubility in
common organic solvents such as DCM, chloroform, THF and
toluene. However, the synthesized molecules are sparingly
soluble in polar aprotic solvents such as DMF and DMSO. Our
objective is to see the effect of the extension of PMI core along
the long molecular axis (specifically at 9-position of PMI), which
enables a systematic comparison of their optical properties. All
6a
6b
6c
6d
6e
6f
42
59
49
69
40
60
46
65
70
55
55
55
40
40
40
40
40
40
31
76
43
71
73
64
52
86
85
55
55
55
40
40
40
40
-
5
83
87
65
73
73
69
68
-
5
10
10
10
10
10
-
5
5
6gc
6h
6ic
5
solvent
dependent
UV-Vis.
absorption,
steady-state
5
fluorescence, and time-resolved fluorescence measurements
were performed at room temperature (298 K). Irrespective of the
5
-
-
-
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10.1002/ejoc.201701310
European Journal of Organic Chemistry
COMMUNICATION
!"#
solvent polarity, the
ꢀ
of the peri-functionalized PMI
measurements. Interestingly, the potential values are very
similar to the peri-functionalized Suzuki-couple product 6ʹ.
Reductions of PMI derivatives were reversible in nature
although in case of oxidation for 6c, 6g, 6h and 6i quasi-
reversible or irreversible peak was observed. Mostly, one
electron oxidation seems much more favourable compared
to unsubstituted PMI except in case of 6a. Interestingly, a
notable variation of ca. 0.15 V was measured in case of
second 1e reduction potential, which is much more difficult
compared to first reduction due to substitution at peri
position and indicating stabilization due to increased
conjugation.
!"#
derivatives 6a-i have a significant shift (ca. 25 nm for 6i and 49
nm in case of 6c) as compared to the parent PMI 1. In toluene, 1
has two major absorption peaks one at 477 nm and other at ca.
504 nm. It indicates, that there is noteworthy variation in the
vibrational energy of the excited PMI derivatives upon
substitution. However, when it was coupled at the peri position, it
was bathochromically shifted with different extent. In compound
6a, tolyl group is present at the peri position of PMI, leading the
!"#
ꢀ
bathochromically shifted by 31 nm in case of 1 in toluene. It
!"#
is fair enough to compare the parent PMI 1, the Suzuki-coupled
PMI 6' with the π-extended sonogashira-coupled PMI 6a as the
methyl group on the tolyl phenyl has a negligible electronic effect
(Figure 2(a) and Table 2). To verify, we have performed DFT
calculations to find out the HOMO-LUMO energy of selected PMI
derivatives (Fig. S55 and Table S2) and the electron density and
Table 2 Optical and electrochemical properties of PMI 1, 6', and peri-coupled
PMI derivatives 6a-ia
matches well with the values obtained for similar molecules.[14]
of 6' bathocromically shifted by 11 nm in comparison
to 1 in toluene, whereas the ꢀ
!"#
ꢀ ꢀ10!/
ꢀ
τavg
Er
(1)
/V
Er
(2)
/V
PMI
Φfb
Eo (1)
/V
!"
!"#
The ꢀ
ꢀ!!ꢀꢁ!!
,
!"#
/nm
/ns
!"#
!"#
of 6a is bathochromically
(ꢀ
!"#
!"#
/nm)
shifted by 20 nm with respect to 6', showing the effect of C≡C
spacer in the ground state along the long axis of the perylene.
1
4.0, (504)
4.0, (515)
4.7, (535)
4.3, (535)
4.1, (537)
3.4, (530)
4.8, (536)
5.4, (536)
4.6, (540)
5.5, (533)
5.2, (530)
526
545
555
565
635
560
560
560
620
560
555
0.48
0.99
0.81
0.79
0.62
0.50
0.84
0.84
0.87
0.88
0.98
4.7
4.4
3.5
3.5
3.0
3.4
3.2
3.3
3.0
3.5
3.7
–
1.20
1.42
1.35
1.27
1.25
1.22
1.20
1.20
1.30
1.26
1.26
1.08
1.35
1.35
1.26
0.90c
1.27
1.18c
1.26
!"#
There is a minor spectral shift of 2 nm and 5 nm in ꢀ
in the
!"#
case of 6c and 6g respectively, with respect to 6a (Table 2 and
6ʹ
0.95
0.95
0.95
0.95
0.90
0.93
0.90
0.95
0.91
0.91
!"#
S1). However, in case of polar solvent DMF the ꢀ
of 6c and
!"#
6a
6b
6c
6d
6e
6f
6g are bathochromically shifted 10 to 20 nm with respect to 6a
(Table S1). The steady-state fluorescence measurement of PMI
!"#
1, 6', and 6a in toluene shows that emission maxima (ꢀ
) of 6'
!"
is bathochrmically shifted by 19 nm with respect to 1, and for 6a
it was bathochromically shifted by 10 nm in comparison to 6'
(Figure 3).
1
(a)
1.0
(b)
1.0
6a
6b
1
6c
'
6
6e
6g
6i
6g
6h
6i
0.95d
6a
0.5
0.0
0.5
0.0
e
e
500
550
600 650
Wavelength/ nm
700
750
500
550
600 650
Wavelength/ nm
700
750
aOptical and electrochemical properties are measured in toluene and
dichloromethane respectively; the half-wave potential Er/o was set equal to 0.5
(Epa + Epc), where Epa and Epc are anodic and cathodic peak potentials,
respectively. bΦf was measured with reported reference compound 2,6-
Diisopropylaniline substituted PMI in toluene.[7] csplit observed in cathodic CV
peak. doxidation was irreversible. eno distinct peak was observed.
Figure 3. Normalized emission spectra of (a) 1, 6', 6a; and (b) 1 with some
representative PMI derivative in toluene
!"#
The ꢀ
of peri-coupled PMI derivatives 6a-i are red-
!"
shifted by 29-109 nm in toluene with respect to PMI 1
In conclusion, we have developed a simple microwave-assisted
synthetic protocol for a series of peri-coupled PMI derivatives by
Sonogashira coupling at reaction rates that are significantly
faster than conventional techniques with high reaction yield can
be utilized for other dyes and polymer chemistry. These
molecules display high molar extinction coefficient, near-unity
(Table 2). For electron-rich functional derivatives i.e., 6c
!"#
and 6g, the ꢀ
red-shifted by 109 nm and 94 nm
!"
respectively. The quantum yield of the compounds 6a-i is
quite high except 6c (0.62) and 6d (0.50) in toluene (Table
2). In polar solvents, φf of 6c and 6g are quite low (see SI)
due to strong dipolar interactions with solvents. The time-
resolved measurements of 6a-i show the lifetime spanning
from 1.5 ns to 3.9 ns in dichloromethane. However, we did
not observe any significant changes in fluorescence lifetime
with solvent polarity (see Table S1) except in case of 6g.
Akin to UV-Vis. properties, not much alternation in the first
1e reduction potential value was observed upon substitution
at peri position as can be seen from the electrochemical
fluorescence
quantum
yield,
substitution-dependent
optoelectronic properties, and electrochemical properties with a
real promise for different applications. Currently, we are
exploring their potential in fluorescent materials and solar-cell
applications.
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COMMUNICATION
S. I. Stupp, J. Am. Chem. Soc. 2015, 137, 15241-15246; (h) R. V. Kazantsev,
A. J. Dannenhoffer, A. S. Weingarten, B. T. Phelan, B. Harutyunyan, T. Aytun,
A. Narayanan, D. J. Fairfield, J. Boekhoven, H. Sai, A. Senesi, P. I.
O’Dogherty, L. C. Palmer, M. J. Bedzyk, M. R. Wasielewski, S. I. Stupp, J. Am.
Chem. Soc. 2017, 139, 6120-6127.
Acknowledgements
We would like to thank IISERB and BRNS, DAE
(37(2)/14/33/2014-BRNS/557) for funding. Fellowship support
from CSIR (for VS), IISERB (for FC and DS) is highly
acknowledged. We sincerely thank Dr. Srikanta Patra and his
co-workers from IIT Bhubaneswar for their help with CV
measurements. Finally, we are thankful to anonymous referees
for their invaluable suggestions.
[5]
(a) R. S. Loewe, K.-y. Tomizaki, F. Chevalier, J. S. Lindsey, J. Porphyr.
Phthalocyanines 2002, 06, 626-642; (b) K.-y. Tomizaki, P. Thamyongkit, R. S.
Loewe, J. S. Lindsey, Tetrahedron 2003, 59, 1191-1207; (c) H. Quante, K.
Müllen, Angew. Chem. Int. Ed. 1995, 34, 1323-1325.
[6]
(a) P. Schlichting, B. Duchscherer, G. Seisenberger, T. Basché, C.
Bräuchle, K. Müllen, Chem. Eur. J. 1999, 5, 2388-2395; (b) D. Gosztola, M. P.
Niemczyk, M. R. Wasielewski, J. Am. Chem. Soc. 1998, 120, 5118-5119.
Keywords: Perylene dyes • sonogashira coupling • microwave-
[7]
D. F. Bocian, D. Holten, J. S. Lindsey, J. Org. Chem. 2002, 67, 6519-6534.
[8] T. Edvinsson, C. Li, N. Pschirer, J. Schöneboom, F. Eickemeyer, R.
K.-y. Tomizaki, R. S. Loewe, C. Kirmaier, J. K. Schwartz, J. L. Retsek,
assisted synthesis • photophysics • organic electronics
Sens, G. Boschloo, A. Herrmann, K. Müllen, A. Hagfeldt, J. Phys. Chem. C
2007, 111, 15137-15140.
[1]
(a) L. Chen, C. Li, K. Mullen, J. Mater. Chem. C 2014, 2, 1938-1956; (b)
H. Langhals, Heterocycles 1995, 40, 477-500; (c) M. P. O'Neil, M. P.
Niemczyk, W. A. Svec, D. Gosztola, G. L. Gaines, M. R. Wasielewski, Science
1992, 257, 63-65.
[9]
M. J. Ahrens, M. J. Fuller, M. R. Wasielewski, Chem. Mater. 2003, 15,
2684-2686.
[10] (a) C. O. Kappe, D. Dallinger, Nat. Rev. Drug Discov. 2006, 5, 51-63;
(b) M. B. Gawande, S. N. Shelke, R. Zboril, R. S. Varma, Acc. Chem. Res.
2014, 47, 1338-1348; (c) J. P. Saludes, D. Sahoo, I. A. Monreal, New J. Chem.
2014, 38, 507-510; (d) M. Sekita, Á. J. Jiménez, M. L. Marcos, E. Caballero, M.
S. Rodríguez-Morgade, D. M. Guldi, T. Torres, Chem. Eur. J. 2015, 21, 19028-
19040.
[2]
(a) K. Pal, V. Sharma, A. L. Koner, Chem. Commun. 2017, 53, 7909-
7912; (b) J. Hofkens, L. Latterini, G. De Belder, T. Gensch, M. Maus, T. Vosch,
Y. Karni, G. Schweitzer, F. C. De Schryver, A. Hermann, K. Müllen, Chem.
Phys. Lett. 1999, 304, 1-9; (c) E. Z. M. Ebeid, S. A. El-Daly, H. Langhals, J.
Phys. Chem. 1988, 92, 4565-4568; (d) H. Langhals, Chem. Ber. 1985, 118,
4641-4645.
[11] (a) F. Rigodanza, E. Tenori, A. Bonasera, Z. Syrgiannis, M. Prato, Eur.
J. Org. Chem. 2015, 2015, 5060-5063; (b) Z. Yuan, S.-L. Lee, L. Chen, C. Li,
K. S. Mali, S. De Feyter, K. Müllen, Chem. Eur. J. 2013, 19, 11842-11846.
[12] V. Sharma, D. Sahoo, F. Chandra, A. L. Koner, Submitted 2017.
[13] H. Langhals, A. Hofer, J. Org. Chem. 2012, 77, 9585-9592.
[14] (a) X. Zhao, Y. Xiong, J. Ma, Z. Yuan, J. Phys. Chem. A 2016, 120,
7554-7560; (b) R. Turrisi, A. Sanguineti, M. Sassi, B. Savoie, A. Takai, G. E.
Patriarca, M. M. Salamone, R. Ruffo, G. Vaccaro, F. Meinardi, T. J. Marks, A.
Facchetti, L. Beverina, J. Mater. Chem. A 2015, 3, 8045-8054.
[3]
[4]
L. Feiler, H. Langhals, K. Polborn, Liebigs Ann. 1995, 1995, 1229–1244.
(a) M. A. Miller, R. K. Lammi, S. Prathapan, D. Holten, J. S. Lindsey, J.
Org. Chem. 2000, 65, 6634-6649; (b) S. Prathapan, S. I. Yang, J. Seth, M. A.
Miller, D. F. Bocian, D. Holten, J. S. Lindsey, J. Phys. Chem. B 2001, 105,
8237-8248; (c) S. I. Yang, S. Prathapan, M. A. Miller, J. Seth, D. F. Bocian, J.
S. Lindsey, D. Holten, J. Phys. Chem. B 2001, 105, 8249-8258; (d) S. I. Yang,
R. K. Lammi, S. Prathapan, M. A. Miller, J. Seth, J. R. Diers, D. F. Bocian, J. S.
Lindsey, D. Holten, J. Mater. Chem. 2001, 11, 2420-2430; (e) D. Sahoo,
University of Bielefeld (Germany), 2009; (f) Y. Hu, S. Chen, L. Zhang, Y.
Zhang, Z. Yuan, X. Zhao, Y. Chen, J. Org. Chem. 2017, 82, 5926-5931; (g) A.
S. Weingarten, R. V. Kazantsev, L. C. Palmer, D. J. Fairfield, A. R. Koltonow,
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COMMUNICATION
Entry for the Table of Contents : Perylenemonoimide Dyes
COMMUNICATION
Faster than conventional coupling!
Vikas Sharma, Falguni Chandra,
A
simple
synthetic protocol for a series of peri-
coupled PMI derivatives by
Sonogashira coupling is reported.
microwave-assisted
Dhananjaya Sahoo,* Apurba L. Koner*
Page No. – Page No.
An
Efficient
Microwave-assisted
Synthesis of Sonogashira-coupled
PMI Derivatives: Impact of Electron
Donating Groups on Optoelectronic
Properties
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