Porphyrin Derivatives of Macrocyclic Tetraindoles: Synthesis and Chemical Transformations

Article abstract of DOI:10.1134/S0012500818050026

Polyphenols chemically bonded to a molecular platform based on macrocyclic tetraindole porphyrin derivatives were synthesized for the first time. The tetraindole was prepared by two-step tetramerization of 3-(4′-bromophenyl)-4,6-dimetoxyindole. Polyphenols of this type were obtained by the Suzuki–Miyaura reaction between bromo-containing cyclic tetraindole and monoboryl-substituted porphyrin. The subsequent transformations of this molecular construction gave rise to epoxidized polyphenol on a tetraindole support, which served for the development of a new negative resist for electron-beam nanolithography. The resist can form patterns with a 12 nm resolution.

Full text of DOI:10.1134/S0012500818050026

ISSN 0012-5008, Doklady Chemistry, 2018, Vol. 480, Part 1, pp. 77–80. © Pleiades Publishing, Ltd., 2018.
Original Russian Text © A.Ya. Vainer, K.M. Dyumaev, A.M. Kovalenko, N.V. Barannik, K.I. Zelikson, S.V. Kotov, 2018, published in Doklady Akademii Nauk, 2018, Vol. 480,
No. 1, pp. 45–49.
CHEMISTRY
Porphyrin Derivatives of Macrocyclic Tetraindoles:
Synthesis and Chemical Transformations
A. Ya. Vainer*, Corresponding Member of the RAS K. M. Dyumaev, A. M. Kovalenko,
N. V. Barannik, K. I. Zelikson, and S. V. Kotov
Received December 13, 2017
Abstract—Polyphenols chemically bonded to a molecular platform based on macrocyclic tetraindole porphy-
rin derivatives were synthesized for the first time. The tetraindole was prepared by two-step tetramerization
of 3-(4'-bromophenyl)-4,6-dimetoxyindole. Polyphenols of this type were obtained by the Suzuki–Miyaura
reaction between bromo-containing cyclic tetraindole and monoboryl-substituted porphyrin. The subse-
quent transformations of this molecular construction gave rise to epoxidized polyphenol on a tetraindole sup-
port, which served for the development of a new negative resist for electron-beam nanolithography. The resist
can form patterns with a 12 nm resolution.
DOI: 10.1134/S0012500818050026
Numerous indole derivatives form an important binders of resists for nanolithography. Compounds of
class of heterocyclic compounds. Their synthetic this architecture are expected to have high rigidity and
accessibility and high electrophysical and thermal thermal stability.
properties open up prospects for their use as hole-con-
In this study, we demonstrated for the first time the
ducting materials, organic light-emitting diodes, solar
possibility to prepare monodisperse polyphenols
batteries, and donor-acceptor dyes [1]. The applica-
chemically bound to a rigid thermally stable molecular
tion of such products for the manufacture of optoelec-
platform based on porphyrin derivatives of macrocy-
tronic and electronic materials gives rise to interest in
clic tetraindole. We prepared these polyphenols by a
the synthesis of new indole derivatives possessing
facile and convenient procedure comprising the
unusual functional properties.
Suzuki–Miyaura reaction of bromo-containing cyclic
A recent attempt to prepare new porphyrin ana-
logues resulted in the synthesis of macrocyclic tetrain-
doles [2–4], in which each pyrrole moiety, together
with the neighboring meso carbon atom is replaced by
an indole group. One more approach used to prepare
macrocyclic tetraindoles is the synthesis of saddle–
shaped cyclic indole tetramers, in which four indole
moieties are chemically bonded to the cyclooctatet-
raene central core [1, 5, 6]. Both types of macrocyclic
tetraindoles with a pseudoporphyrin architecture are
considered as promising building blocks for the design
of indole-containing optoelectronic and electronic
materials.
In recent years, we have been developing a new
concept of synthesis of monodisperse polyphenols
chemically bonded to a rigid thermally stable molecu-
lar platform [7]. In our opinion, in this context, por-
phyrin derivatives of macrocyclic tetraindoles are of
obvious interest for assembling polyphenols suitable as
tetraindole and boryl-substituted porphyrin. The sub-
sequent chemical transformations of this molecular
construction resulted in the synthesis of epoxidized
polyphenol on a tetraindole support with porphyrin
side groups, which made it possible to develop new
negative resists for electron-beam nanolithography.
The corresponding radiation-sensitive systems made it
possible to form patterns with a 12 nm resolution.
Unless specified otherwise, Sigma-Aldrich (US)
chemicals were used. All experiments were carried out
under argon using the standard Schlenk techniques.
The synthesis and chemical reactions of the polyphe-
nol derivative of porphyrin tetraindole macrocycle are
shown in Scheme 1.
Reagents and conditions: (a) SnCl4, CH2Cl2/MeNO2
(3 : 1 v/v), refluxing, 12 h, 48%; (b) HCl, p-benzoqui-
none, CH2Cl2, 22°C,
3
h, 47%; (c) IV,
(([dppf]Fe)PdCl2), KOAc, DMSO, 80°C, 6 h, 66%;
(d) V, BBr3, CH2Cl2, 22°C, 3 h, 95%; (e) 1-bro-
momethylcyclohex-3-ene, DBU, HMPA, 60°C, 24 h,
86%; (f) TBHP, DBU, THF, 22°C, 10 h, 93%.
All-Russian Research Institute of Medicinal and Aromatic
Plants, Moscow, 117216 Russia
*e-mail: nvbarannik@mail.ru
3-(4'-Bromophenyl)-4,6-dimetoxyindole (I) obtai-
ned by procedure [8] was subjected to dimerization as
77

78
VAINER et al.
Br
Br
Br
Br
OMe
MeO
OMe
OMe
(a)
(b)
N
NHHN
NH HN
MeO
MeO
H
MeO
OMe
Br
A'
NH
N
MeO
H
Br
Br
I
MeO
A
OMe
II
OMe
MeO
OMe
III
A'
A
(c)
HO
OH
MeO
OMe
(d)
NHHN
NHHN
NH HN
HO
OH
MeO
OMe
NH HN
A'
A'
A
A
HO
OH
MeO
OMe
HO
A''
OH
MeO
OMe
A'''
VI
V
(e)
A''
A'''
RO
OR
OR'
OR'
(f)
NHHN
NHHN
NH HN
RO
OR
OR'
OR'
NH HN
A''
A''
A'''
A'''
RO
OR
VII
OR'
OR'
RO
MeO
OR
OMe
R'O
HO
OR'
VIII
OH
OMe
OH
OH
NH
NH
N
N
A =
A' =
N
N
HN
HN
OMe
R =
H2
C
MeO
RO
OMe
OR
HO
OR'
OH
OR'
O
H2
C
R' =
OR
OR
OR'
OR'
NH N
NH N
A'' =
A''' =
N
N
HN
HN
RO
OR
OR'
OR'
Scheme 1. Reagents and conditions: (a) SnCl , CH Cl /MeNO (3 : 1 v/v), refluxing, 12 h, 48%; (b) HCl, p-benzoquinone,
4
2
2
2
CH Cl , 22°С, 3 h, 47%; (c) IV, (([dppf]Fe)PdCl ), KOAc, DMSO, 80°С, 6 h, 66%; (d) V, BBr , CH Cl , 22°С, 3 h, 95%;
2
2
2
3
2
2
(e) 1-bromomethylcyclohex-3-ene, DBU, HMPA, 60°С, 24 h, 86%; (f) TBHP, DBU, THF, 22°С, 10 h, 93%.
described in [2] to give 3,3'-bis(4'-bromophenyl)- macrocyclic tetraindole (III). The reaction was car-
4,4',6,6'-tetramethoxy-1H, 1'H-2,7'-bis-indole (II).
Then dimer II was oxidized with p-benzoquinone in a
CH2Cl2–nitromethane (MeNO2) mixture to give
ried out by a reported procedure [2]. Tetramer III was
treated with 5-[4'-(4'',4'',5'',5''-tetramethyl-1'',3'',2''-
dioxaborolan-2''-yl)phenyl]-10,15,20-tris(3',5'-dime-
DOKLADY CHEMISTRY
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PORPHYRIN DERIVATIVES OF MACROCYCLIC TETRAINDOLES
Table 1. Molecular weights of the products
79
thoxyphenyl)porphyrin (IV) under Suzuki–Miyaura
reaction conditions. Compound IV was synthesized by
the procedure reported in our paper [9] by condensa-
tion of pyrrole, 3,5-dimethoxybenzaldehyde, and 4-
(4',4',5',5'-tetramethyl-1',3',2'-dioxaborolan-2'-yl)ben-
zaldehyde. The cross-coupling was conducted by a
reported procedure [10] in dimethyl sulfoxide
(DMSO) in the presence of the dichloro[1,1-bis(di-
phenylphosphino)ferrocene]palladium ([dppf]Fe]PdCl2)
as the catalyst (Strem Chemical Co., USA). The prod-
uct of this reaction (V) was subjected to exhaustive
demethylation by a known procedure [11] to give poly-
phenol derivative of indole tetramer (VI).
Molecular weight, g/mol
Molecular
formula
Compound
found*
calculated
II
C32H26Br2N2O4
C64H48Br4N4O8
C56H53BN4O8
662.3927
662.3930
III
IV
1320.7536 1320.7542
920.8794
4176.7467
920.8798
4176.7480
V
C264H212N20O32
C232H148N20O32
C456H468N20O32
C456H468N20O64
VI
3727.8806 3727.8812
6740.9291 6740.9292
7252.9091 7252.9100
VII
VIII
Indole-containing polyphenol VI was then treated
with 1-bromomethylcyclohexen-3-one [12], as rec-
ommended in [13], to give unsaturated tetraindole
macrocycle (VII) with cyclohexene side moieties. The
reaction was conducted in a hexamethylphosphora-
mide (HMPA) in the presence of 1,8-diazabicy-
clo[5,4,0]-7-undecene (DBU). Finally, the target
tetramer with epoxide side groups (VIII) was synthe-
sized by treatment of cyclohexene-containing macro-
cycle VII with a solution of tert-butyl hydroperoxide
(TBHP) in tetrahydrofuran (THF) under the action of
DBU according to a procedure we described earlier [14].
*According to MALDI-TOF mass spectrometry.
NH groups) and a band at 1440 cm–1 (pyrrole C=N
groups). Also, the bands at 3406 cm–1 (pyrrole NH
groups) and 1593, 1519, 1463, 1090, 830, and 545 cm–1
were assigned to the tetraindole cyclic core of com-
pound VIII. In the spectrum of compound VI, atten-
tion is attracted by a band at 3526 cm–1, which can be
assigned to phenolic hydroxyl groups. This band com-
pletely disappears for compounds VII and VIII.
1
The newly synthesized compounds II–VIII were
In the H NMR spectrum of VIII (799.809 MHz,
purified by preparative high performance liquid chro- CDCl3), the porphyrin moieties are responsible for
matography (HPLC). Their structures were estab-
the proton signals at δ 2.89 ppm (NH) and in the range
δ 8.75–8.92 ppm (β-H in the porphyrin rings). The
tetraindole core of VIII gives rise to proton signals at
δ 9.76 and 8.64 ppm (NH) and δ 6.02 ppm. The last-
mentioned signal corresponds to protons at the indole
C-5 atom. This 1H NMR spectrum contains no signals
at about 10.24 ppm (phenolic hydroxyl protons) or
δ 3.89 ppm (methoxy group protons).
1
lished by MALDI-TOF mass spectrometry and H
NMR, 13C NMR, and IR spectroscopy and confirmed
by analytical HPLC and elemental analysis data. Table 1
summarizes the molecular weights of the obtained
compounds.
According to IR and NMR spectroscopy data, the
above conditions of epoxidation of unsaturated mac-
rocycle VII were sufficient for complete conversion of
In the 13C NMR spectra (200.13 MHz, CDCl3) of
cyclohexene moieties to epoxycyclohexane ones. After compound VIII, several signals were assigned to the
completion of this reaction, the IR spectrum of mod- porphyrin macrocycle. In particular, the signals for
ified indole-containing tetramer no longer exhibits the meso carbon atoms occur at δ 119.1, 123.14, and
absorption bands for the cyclohexene double bonds 123.7 ppm. The δ 117.3 ppm signal corresponds to the
(3025, 1620 m, and 660 cm–1), but shows new bands
for the oxirane ring vibrations. In particular, low-fre-
quency bands at 816 and 885 cm–1 are of analytical
value.
C-2 and C-5 carbon atoms of the pyrrole rings. The
signal at 107.6 ppm also belongs to the pyrrole rings
(C-3 and C-4). The indole core of compound VIII
gives rise to signals at δ 146.8, 143.7, 140.2, 137.5,
132.5, 129.8, 123.8, 117.5, 115.8, and 107.5 ppm.
The epoxidized tetraindole macrocycle VIII was
used for the development of a new chemically ampli-
fied negative electron-beam resist suitable for the fab-
rication of microchips with cell size of 12 nm. The
negative resist film based on compound VIII and
triphenylsulfonium perfluorobutanesulfonate as the
radiation-sensitive acid generator (5% relative to the
weight of VIII) was formed on a silicon substrate
(Rockwood Electronic Materials) from a solution in
2-acetoxy-1-methoxypropane and was dried at 95°C
for 2 min. The post-exposure drying was performed at
125°C (2 min). The resist was developed with a 3 : 1 v/v
The 1H NMR spectrum of epoxidized macrocycle
VIII exhibits a signal for the methine proton in the
13
oxirane rings (multiplet at δ 3.15 ppm). Also, the C
NMR spectrum of this compound contains a signal
for methine carbon atoms in the oxirane rings at 50.4–
52.2 ppm. Meanwhile, no carbon signal for cyclohex-
ene double bonds is present at 124.7–126.7 ppm.
The obtained analytical data were considered in
more detail in relation to epoxidized tetraindole mac-
rocycle VIII; only those absorption bands and signals
are indicated that are analytically significant for struc-
ture assignment. The IR spectrum of this compound
shows 3311 and 1469 cm–1 absorption bands (pyrrole cyclohexanone/butanol mixture.
DOKLADY CHEMISTRY Vol. 480 Part 1 2018

80
VAINER et al.
The resolution of the negative electron beam resist supported epoxidized polyphenol was used to develop
was determined by irradiating the resist film in a JEOL a new negative resist for electron beam nanolithogra-
JBX-6300FS electron beam system with exposure phy capable of forming 12 nm node patterns.
energy of 100 keV. The resist had a very high resolu-
tion: patterns with 12 nm-wide isolated lines were
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Translated by Z. Svitanko
etherified with 1-bromomethylcyclohexen-3-one,
and the unsaturated derivative was epoxidized by reac-
tion with tert-butyl hydroperoxide. The tetraindole-
DOKLADY CHEMISTRY
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Part 1
2018