Synthesis of cyclopenta-fused polycyclic aromatic hydrocarbons utilizing aryl-substituted anilines

Article abstract of DOI:10.1039/c6ob01235c

Cyclopenta-fused polycyclic aromatic hydrocarbons (CP-PAHs), potentially electronically and biologically highly active materials, were synthesized from readily available 2-aryl-substituted anilines. Reactions occur under extremely mild, room temperature conditions using ^tBuONO as the sole reagent. The use of a nitrite source generates a reactive diazonium intermediate in situ that then reacts with a tethered polycyclic aromatic moiety by intramolecular aromatic substitution. This protocol could be presented as one of the simplest methods to access CP-PAHs.

Full text of DOI:10.1039/c6ob01235c

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DOI: 10.1039/C6OB01235C
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Synthesis of Cyclopenta-fused Polycyclic Aromatic Hydrocarbons
Utilizing Aryl-substituted Anilines
Yeojin Choi,a Tanmay Chatterjee,a Jun Kim,a Jun Soo Kim,b and Eun Jin Cho*,a
Received 00th January 20xx,
Accepted 00th January 20xx
Cyclopenta-fused polycyclic aromatic hydrocarbons (CP-PAHs), potentially electronically and biologically highly active
materials, were synthesized from readily available 2-aryl-substituted anilines. Reactions occur under extremely mild, room
temperature conditions using tBuONO as the sole reagent. The use of nitrite source generates a reactive diazonium
intermediate in situ that then reacts with a tethered polycyclic aromatic moiety by intramolecular aromatic substitution.
This protocal could be presented as one of the simplest methods to access CP-PAHs.
DOI: 10.1039/x0xx00000x
www.rsc.org/
use of a nitrite source generates a reactive diazonium
intermediate in situ,10 that then reacts with a tethered
polycyclic aromatic moiety by intramolecular aromatic
substitution at room temperature.11 Tert-butyl nitrite
(tBuONO) was used as the sole reagent, and the reactivity was
controlled by its stoichiometry and substrate concentration.
Introduction
Polycyclic aromatic hydrocarbons have received considerable
attention as a class of useful materials.1 Notably, cyclopenta-
fused polycyclic aromatic hydrocarbons (CP-PAHs) have been
of great interest due to their high chemical, physical, and
biological activities. These systems show high electron
affinities, resulting in their use in many applications including
various electronic devices such as organic photovoltaic devices
(OPVs) and organic field-effect transistors (OFETs).1a,1c,1e In
Results and discussion
We commenced the investigation by using 2-(phenanthren-9-
addition, CP-PAHs are important as biologically relevant yl)aniline (1a) as the model substrate (Table 1). The use of 1.5
t
species.2 They can be used as DNA intercalators in equiv. of BuONO to diazotize the amine in DMSO (0.25 M) at
chemotherapy to inhibit DNA replication in rapidly growing room temperature produced the desired cyclized compound,
cancer cells.2b,2c Furthermore, they have been widely used in benzo[e]acephenanthrylene (2a), in 54% yield along with
the study of biological effects because of their strong deaminated product 3a (20%) as a side product (Table 1, entry
mutagenic and carcinogenic activities.2a,2d
1). The selection of a suitable solvent was critical to the
This extensive use in a wide array of applications has
necessitated the development of efficient and practical
methods that allow easier access to these compounds. Various
CP-PAHs have been synthesized mainly by Pd-catalyzed Heck-
type processes,3 Friedel-crafts reactions,4 pentannulations,5
transannular cyclization,6 or Fe-mediated Scholl7 reactions.
Moreover, several methods were recently developed using
9
silylium-8 or Al2O3 -mediated aryl couplings of fluoroarenes
[Scheme 1. (1)]. Despite these great advances, many of these
methods are still restricted by limited substrate scope and
harsh reaction conditions including high temperatures or long
reaction times. Herein, we report a metal-free mild protocol
for the synthesis of various CP-PAHs using easily accessible 2-
aryl-substituted anilines [Scheme 1. (2)]. In this process, the
aDepartment of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu,
Seoul 06974, Republic of Korea. E-mail: ejcho@cau.ac.kr, http://ejcho.cau.ac.kr
b Department of Chemistry & Nanoscience, Ewha Womans University, Seoul 03760,
Republic of Korea.
Scheme 1 Synthesis of CP-PAHs.
Electronic Supplementary Information (ESI) available: Additional comments and 1H
and 13C NMR spectra of synthesized substrates and CP-PAHs. See
DOI: 10.1039/x0xx00000x
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reactivity of the process. Among the various solvents tested not affect the reactivity and 2a was afforded in Vsieimw AilraticrleyOienllidne.
(including DMSO, DMF, DCM, dimethyl carbonate, THF, MeOH, Interestingly, the reactivity decreaDsOedI: 10.1u0n3d9e/Cr6OBo0x1y2g3e5Cn
and MeCN), MeCN afforded the best results (2a in 80% yield; atmosphere with slower conversion (Table 1, entry 20).14
A
Table 1, entries 1-7). The use of isopentyl nitrite as the variety of 2-aryl-substituted aniline derivatives were
diazotization reagent also produced the desired product 2a investigated under these optimized conditions. First, 2-
,
but the process required longer reaction times (Table 1, (phenanthren-9-yl)aniline derivatives were tested in 0.5 mmol
entries 8 and 9). The rate of diazonium salt generation might scale (Scheme 2). While 1a and 1b smoothly underwent
t
be slower with isopentyl nitrite than with BuONO. We further cyclization to afford 2a and 2b, respectively, the substrates
conducted optimization studies including the stoichiometry of containing electron-withdrawing substituents on the aniline
tBuONO, substrate concentration, and addition of additives. ring
While the amount of BuONO did not significantly affect the transformation.
(
1c and 1d
)
exhibited less reactivity toward the
The corresponding 6-substituted
t
efficiency in terms of yield (Table 1, entries 7 and 10-12), the benzo[e]acephenanthrylenes 2c and 2d were generated in low
concentration was found to be critical in the reaction; the yield yield. It is likely that the electron withdrawing substituent
decreased greatly at higher concentrations (Table 1, entries 7 affected reactivity in the diazotization step. Interestingly, a
and 13-16). The additional use of an inorganic base (K3PO4) regioisomer 2ci (10%) was also detected in the reaction of 1c
,
and higher temperature (80 °C) prevented the desired indicating that radical species might be involved in the
transformation, resulting only in the formation of deaminated transformation by a minor radical pathway despite very low
15
product 3a (Table 1, entries 17 and 18). The reaction was also yield of 1c
attempted with a triscyclometalated Ir(III) complex, fac-
Ir(ppy)3 which is known to be activated by visible light and afford benzo[a]aceanthrylene (
′.
The compound 2-(anthracen-9-yl)aniline (
4) also reacted to
), but the product showed
5
leads to a variety of radical-mediated photoredox catalysis partial decomposition during the purification process (Scheme
(Table 1, entry 19).12,13 However, the use of a photocatalyst did 3).8
The electron density of the polycyclic aromatic part might
Table 1 Optimization of the reaction conditionsa
also affect the reactivity. Pyrenyl-substituted substrates (6a
and 6b) showed slightly higher reactivity than phenanthrenyl-
substituted substrates to afford the corresponding
indeno[1,2,3-cd]pyrene derivatives, 7a and 7b (Scheme 4). In
the case of 6c containing Cl substituent, the reaction showed
low conversion, providing 18% yield of cyclized product 7c
along with 50% of deaminated product and 24% of recovered
starting substrate 6c
.
Scheme 2 Synthesis of benzo[e]acephenanthrylene derivatives (2a-2d); 1 (0.5 mmol
scale), isolated yield.
Scheme 3 Synthesis of benzo[a]aceanthrylene (5); 4 (0.5 mmol scale).
aReaction scale: 1a (0.1 mmol); bthe yield was determined by gas
chromatography.
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DOI: 10.1039/C6OB01235C
Scheme 4 Synthesis of indeno[1,2,3-cd]pyrene derivatives (7a-7c); 6 (0.5 mmol scale),
isolated yield.
−4.00
−6.03
−4.03
−6.56
−4.04
−6.49
−4.03
−6.61
LUMO (eV)
HOMO (eV)
Scheme 5 Synthesis of fluoranthene (9); 8 (0.5 mmol scale), isolated yield.
Figure 1 Calculated frontier molecular orbital profiles and energy levels for diazonium
intermediates, 8′, 1a′, 6a′, and 13′, obtained by the DFT calculations with B3LYP
functional and 6-31G(d) basis set.
are presented in Figure 1, as well as the HOMO-LUMO energy
separation. In the figure, it is shown that the electron density
in HOMO are localized mostly in the polycyclic aromatic ring
whereas that in LUMO is in the diazotized aryl ring, implying
the possibility of the charge transfer from the polycyclic
aromatic ring to the diazotized aryl ring via the HOMO-LUMO
interaction. When the HOMO-LUMO energy separation is
reduced, the reactivity of CP-PAH synthesis becomes enhanced
due to the higher efficiency of the charge transfer. In Figure 1,
the HOMO-LUMO energy separation decreases in order of the
Scheme 6 Reactions of benzofused-heterocycle-substituted anilines.
On the other hand, 2-(naphthalen-1-yl)aniline (
less reactivity so that its reaction did not proceed well at room experimental findings that the reactivity is the greatest for 6a
temperature. Thus, it afforded fluoranthene ( ) in only 20% (containing pyrene moiety) followed by 1a
(containing
′ (containing naphthalene moiety)
and 13′ (containing benzothiophene moiety). It is noted that
8) exhibited intermediates 13′
> 8′> 1a′> 6a′, consistent with our
′
9
′
yield. When the temperature was increased to 80 °C,
obtained in 65% yield after 20 h (Scheme 5).
9 was phenanthrene moiety),
8
Benzo-fused heterocycle-substituted anilines were also tested the agreement is only qualitative. The difference in the HOMO-
as possible substrates for this transformation (Scheme 6). LUMO energy separation is not very significant between
′ and
8
However, these reactions did not display good reactivity 1a′ and there must be some other factors that additionally
toward the intramolecular substitution reaction. The affect the reactivity. However, the HOMO-LUMO energy
compound 2-(isoquinolin-4-yl)aniline (10) did not undergo separation provides the qualitative explanation on the
cyclization, but afforded the deaminated product (12). The dependence of the reactivity on the polycyclic aromatic ring.
reaction of 2-(benzo[b]thiophen-3-yl)aniline (13) provided the
A proposed mechanism for this reaction, using 1a, is outlined
desired product (14) only in 10% yield. The deaminated in Scheme 7. This process is initiated by the BuONO-mediated
product (15, 75% yield) and benzo[4,5]thieno[2,3-c]cinnoline16 diazotization of 1a to form the corresponding diazonium
t
(16, 10% yield) were also formed.
compound (1a′) in situ. Its subsequent intramolecular aromatic
To understand the difference in reactivity dependent on the substitution with the tethered phenanthrene moiety generates
tethered polycyclic aromatic ring, the density functional theory the corresponding benzo[e]acephenanthrylene, 2a. However,
(DFT, B3LYP/6-31G(d)) calculations were conducted. The considering the formation of deaminated side product (3a), we
orbital coefficients of the highest occupied molecular orbitals cannot exclude the radical pathway where the aryl radical (3a′
)
(HOMO) and the lowest unoccupied molecular orbitals (LUMO) could be generated by a homolytic cleavage from compound
of diazonium intermediates, generated from
8
,
1a
,
6a, and 13
,
(1a′′) that is in equilibrium with 1a′. The formation of 3a is
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The cyclopenta-fused polycyclic aromatic hydrocarbons were
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characterized by 1H, 13C NMR and FT-IR spectroscopy. NMR spectra were
DOI: 10.1039/C6OB01235C
1
recorded on a Varian 600 MHz instrument (600 MHz for H NMR and 151
MHz for 13C NMR) and a Varian 300 MHz instrument (300 MHz for 1H
1
NMR). Copies of H and 13C NMR spectra can be found at the end of the
Supporting Information. 1H NMR experiments are reported in units, parts
per million (ppm), and were measured relative to residual chloroform (7.26
ppm) in the deuterated solvent. 13C NMR spectra are reported in ppm
relative to deuterochloroform (77.23 ppm), and all were obtained with 1H
decoupling. Coupling constants were reported in Hz. FT-IR spectra were
recorded on a Nicolet iS 10 ThermoFisher FT-IR spectrometer. Reactions
were monitored by GC-MS using the Agilent GC 7890B/5977A inert MSD
with Triple-Axis Detector.
General procedure
Synthesis of substrates (1a-1d, 4, 6a-6c, 8 and 10)
To 2-iodoaniline (1.10 g, 5 mmol) in toluene–EtOH–H2O (4:1:1, 40 mL) at
room temperature were added K2CO3 (1.04 g, 1.50 equiv.), phenanthren-9-
ylboronic acid (1.33 g, 1.20 equiv.), and tetrakis(triphenylphosphine)-
palladium (289 mg, 5.0 mol%). The reaction mixture was stirred at 100 °C
for 4 h. After cooling to room temperature, the phases were separated and
the aqueous phase was extracted with EtOAc. The organic layers were
combined, dried over MgSO4, and concentrated in vacuo. The residue was
purified by flash silicagel-column chromatography, affording the desired
product 1a. Similarly, 1b, 1c, 1d, 4, 6a, 6b, 6c, 8 and 10 were synthesized,
using following substrates. In the case of 1b, 4, and 10, DME–H2O (1.5:1,
35 mL) was used as the solvent system. And for 13, Pd(dba)2/XPhos
catalytic system was used in n-butanol.
For 1b: 2-bromo-4-methylaniline, phenanthren-9-ylboronic acid
For 1c: 2-iodo-4-chloroaniline, phenanthren-9-ylboronic acid
Scheme 7 Proposed mechanism.
For 1d: 2-methyl-4-amino-3-iodobenzoate, phenanthren-9-ylboronic acid
For 4: 9-bromoanthracene, 2-aminophenylboronic acid pinacol ester
For 6a: 2-iodoaniline, pyren-1-ylboronic acid
For 6b: 2-bromo-4-mehtylaniline, pyren-1-ylboronic acid
For 6c: 2-iodo-4-chloroaniline, pyren-1-ylboronic acid
For 8: 2-iodoaniline, naphthalene-1-boronic acid
For 10: 4-bromoisoquinoline, 2-aminophenylboronic acid pinacol ester
For 13: 2-boromoaniline, benzo[b]thiophen-3-ylboronic acid
likely a result of hydrogen atom abstraction of aryl radical 3a′
.
In addition, 3a′ could also undergo intramolecular cyclization
by radical aromatic substitution to provide the desired product
2a as a minor pathway (See Scheme S1 in the SI).
Conclusions
Synthesis of CP-PAHs
We developed a simple method for the preparation of CP-
PAHs. The process, based on in situ generation of diazonium
salts, transforms readily available 2-aryl-substituted anilines
into the target products by an intramolecular aromatic
substitution. Notably, the reactions occur under extremely
The oven-dried tube with magnetic bar was charged with the substrate (0.5
mmol) and MeCN (2 mL). After dissolving the substrate (warming with heat
gun if there was solubility issue), 1.5 equiv. tBuONO was added to the tube.
o
The reaction mixture was stirred for 10 h at room temperature (80 C for 9
and 1c). The reaction progress was monitored by TLC or gas
chromatography. The reaction mixture was concentrated in vacuo and
purified by flash silicagel-column chromatography. When required, the
product was further purified by recrystallization (using ethanol) or by
t
mild, room temperature conditions using BuONO as the sole
reagent. We present our protocol as one of the simplest
methods to access potentially electronically and biologically
highly valuable molecules, CP-PAHs.
preparative thin layer chromatography. [For 1d and 7b, 0.2
M
concentration of MeCN (1.5 mL) and DCM (1 mL) was used due to low
solubility of the substrates.]
2-(phenanthren-9-yl)aniline (1a).17 Light orange solid; 1H NMR (600 MHz,
CDCl3) δ 8.84 (d, J = 8.0 Hz, 1H), 8.80 (d, J = 8.3 Hz, 1H), 7.96 (d, J = 7.8
Hz, 1H), 7.84 (d, J = 8.4 Hz, 1H), 7.83 (s, 1H), 7.79–7.71 (m, 2H), 7.70 (dd,
J = 7.8, 7.3 Hz, 1H), 7.62 (dd, J = 8.0, 7.3 Hz, 1H), 7.39 (dd, J = 8.0, 7.7
Hz, 1H), 7.34 (d, J = 7.4 Hz, 1H), 7.02 (dd, J = 7.7, 7.4 Hz, 1H), 6.91 (d, J
= 8.0 Hz, 1H), 3.54 (s, 2H); 13C NMR (151 MHz, CDCl3) δ 144.65, 135.73,
131.90, 131.30, 130.87, 130.77, 130.30, 129.02, 128.80, 128.48, 128.46,
126.96, 126.96, 126.90, 126.87, 125.92, 123.06, 122.69, 118.50, 115.44;
IR (neat): νmax = 3468, 3376, 2983, 1734, 1237, 1043, 736 cm-1; Rf 0.65
(hex/EtOAc, 4/1).
Experimental
General reagent information
Anhydrous DCM and MeCN were purchased from Sigma-Aldrich
chemical company in Sure-Seal bottles and degassed by repeated
sonication under light vacuum and replenishing the atmosphere with
argon. tBuONO was purchased from Acros Organics. All other
reagents were purchased from Sigma-Aldrich, Alfa Aesar, Acros
Organics, TCI companies or Combi-Blocks. Gravity column
chromatography was performed using Merck silica gel 60 (70-230
mesh).
4-methyl-2-(phenanthren-9-yl)aniline (1b). Light yellow sticky oil; 1H
NMR (600 MHz, CDCl3) δ 8.83 (d, J = 8.2 Hz, 1H), 8.79 (d, J = 8.2 Hz, 1H),
7.95 (d, J = 7.9 Hz, 1H), 7.83 (d, J = 8.2 Hz, 1H), 7.81 (s, 1H), 7.76–7.71
(m, 2H), 7.68 (dd, J = 8.2, 7.9 Hz, 1H), 7.61 (dd, J = 8.2, 8.1 Hz, 1H), 7.19
General analytical information
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(d, J = 8.1 Hz, 1H), 7.15 (s, 1H), 6.83 (d, J = 8.1 Hz, 1H), 3.43 (s, 2H), 2.42 methyl benzo[e]acephenanthrylene-10-carboxylate (2d). White solid
(s, 3H); 13C NMR (151 MHz, CDCl3) δ 142.16, 135.98, 131.96, 131.76, (61 mg, 39%); m. p. 217–218 oC; 1H NMR (600 MHz, CDClV3i)ewδ A8r.t6ic3le(Od,nlJin=e
DOI: 10.1039/C6OB01235C
130.93, 130.78, 130.31, 129.59, 128.80, 128.42, 127.70, 127.05, 126.96, 8.0 Hz, 1H), 8.60 (s, 1H), 8.47 (d, J = 8.1 Hz, 1H), 8.23 (s, 1H), 8.10 (d, J =
126.95, 126.85, 126.85, 126.12, 123.07, 122.70, 115.66, 20.65; IR (neat): 7.9 Hz, 1H), 8.03 (d, J = 7.8 Hz, 1H), 7.99 (d, J = 7.1 Hz, 1H), 7.91 (d, J =
νmax = 3373, 3015, 1616, 1502, 1285, 904, 722 cm-1; HRMS m/z (EI) calc. 7.9 Hz, 1H), 7.76 (dd, J = 8.0, 7.8 Hz, 1H), 7.70 (dd, J = 8.1, 7.4 Hz, 1H),
for C21H17N [M+] 283.1361, found 283.1359; Rf 0.47 (hex/EtOAc, 4/1).
7.64 (dd, J = 7.8, 7.4 Hz, 1H), 4.00 (s, 3H); 13C NMR (151 MHz, CDCl3) δ
167.46, 144.85, 138.64, 136.00, 134.25, 134.09, 132.94, 130.92, 130.62,
129.83, 129.14, 128.48, 127.86, 127.58, 127.20, 123.34, 123.29, 122.93,
122.62, 121.15, 120.78, 52.39; IR (neat): νmax = 2951, 1716, 1433, 1294,
1257, 1232, 1093, 739 cm-1; HRMS m/z (EI) calc. for C22H14O2 [M+]
310.0994, found 310.0992; Rf 0.42 (hex/EtOAc, 8/1).
4-chloro-2-(phenanthren-9-yl)aniline (1c). White solid; m. p. 136–138 oC;
1H NMR (600 MHz, CDCl3) δ 8.78 (d, J = 8.2 Hz, 1H), 8.74 (d, J = 8.2 Hz,
1H), 7.90 (d, J = 8.3 Hz, 1H), 7.72 (s, 1H), 7.72–7.66 (m, 3H), 7.64 (dd, J =
8.0, 7.9 Hz, 1H), 7.56 (dd, J = 8.1, 8.0 Hz, 1H), 7.27–7.21 (m, 2H), 6.78 (d,
J = 8.4 Hz, 1H), 3.52 (s, 2H); 13C NMR (151 MHz, CDCl3) δ 143.46, 134.49,
131.82, 130.94, 130.92, 130.54, 130.47, 128.97, 128.93, 128.73, 127.45, 2-(anthracen-9-yl)aniline (4). Orange oil; 1H NMR (600 MHz, CDCl3) δ
127.27, 127.21, 127.18, 127.15, 126.74, 123.26, 123.15, 122.81, 116.61; 8.53 (s, 1H), 8.07 (d, J = 8.4 Hz, 2H), 7.72 (d, J = 8.8 Hz, 2H), 7.51–7.47
IR (neat): νmax = 3473, 3383, 3061, 1613, 1485, 1282, 904, 725 cm-1; (m, 2H), 7.43–7.35 (m, 3H), 7.18 (d, J = 7.4 Hz, 1H), 6.99 (dd, J = 7.4, 7.3
HRMS m/z (EI) calc. for C20H14ClN [M+] 303.0815, found 303.0812; Rf Hz, 1H), 6.94 (d, J = 8.1 Hz, 1H), 3.32 (s, 2H); 13C NMR (151 MHz, CDCl3)
0.49 (hex/EtOAc, 4/1).
δ 144.97, 133.26, 132.10, 131.68, 130.32, 129.02, 128.53, 127.00, 126.43,
125.82, 125.35, 123.48, 118.49, 115.47; IR (neat): νmax = 3470, 3378,
3049, 1611, 1499, 1452, 1296, 733 cm-1; Rf 0.53 (hex/EtOAc, 4/1).
methyl 4-amino-3-(phenanthren-9-yl)benzoate (1d). White solid; m. p.
215–217 oC; 1H NMR (600 MHz, CDCl3) δ 8.79 (d, J = 8.3 Hz, 1H), 8.75 (d,
J = 8.3 Hz, 1H), 7.99 (dd, J = 8.4, 2.0 Hz, 1H), 7.97 (d, J = 2.0 Hz, 1H),
7.90 (d, J = 7.6 Hz, 1H), 7.75 (s, 1H), 7.73–7.67 (m, 2H), 7.67–7.62 (m,
2H), 7.54 (dd, J = 8.0, 7.9 Hz, 1H), 6.82 (d, J = 8.4 Hz, 1H), 3.94 (s, 2H),
o
2-(pyren-1-yl)aniline (6a). Yellowish solid; m. p. 97–99 C; 1H NMR (600
MHz, CDCl3) δ 8.28 (d, J = 7.7 Hz, 1H), 8.25 (d, J = 6.8 Hz, 1H), 8.21 (d, J
= 6.8 Hz, 1H), 8.14 (s, 2H), 8.10–7.95 (m, 4H), 7.43–7.31 (m, 2H), 7.08–
3.86 (s, 3H); 13C NMR (151 MHz, CDCl3) δ 167.42, 149.20, 134.54, 133.43, 7.00 (m, 1H), 6.93 (d, J = 7.7 Hz, 1H), 3.55 (s, 2H); 13C NMR (151 MHz,
131.88, 131.27, 130.95, 130.58, 130.55, 128.95, 127.25, 127.17, 127.13, CDCl3) δ 144.60, 134.44, 131.73, 131.44, 131.15, 130.98, 129.13, 129.01,
126.73, 124.95, 123.26, 122.81, 119.97, 114.41, 51.87 (overlapped peaks 128.15, 127.86, 127.64, 127.46, 126.37, 126.19, 125.49, 125.30, 125.23,
present); IR (neat): νmax = 3480, 3362, 1695, 1617, 1289, 1254, 769, 727 125.21, 125.10, 124.92, 118.54, 115.51; IR (neat): νmax = 3468, 3375,
cm-1; HRMS m/z (EI) calc. for C22H17NO2 [M+] 327.1259, found 327.1259; 2982, 1734, 1372, 1234, 1043, 848 cm-1; Rf 0.41 (hex/EtOAc, 4/1).
Rf 0.32 (hex/EtOAc, 4/1).
4-methyl-2-(pyren-1-yl)aniline (6b). White solid; m. p. 148–150 oC; 1H
benzo[e]acephenanthrylene (2a).18 White solid (95 mg, 75%); 1H NMR NMR (600 MHz, CDCl3) δ 8.26 (d, J = 7.7 Hz, 1H), 8.22 (d, J = 7.6 Hz,
(600 MHz, CDCl3) δ 8.67 (d, J = 8.1 Hz, 1H), 8.47 (d, J = 8.2 Hz, 1H), 8.23 1H), 8.19 (d, J = 7.6 Hz, 1H), 8.12 (s, 2H), 8.06–8.01 (m, 2H), 7.99 (d, J =
(s, 1H), 8.06 (d, J = 8.0 Hz, 1H), 8.01 (d, J = 7.5 Hz, 1H), 8.00 (d, J = 7.4 7.7 Hz, 1H), 7.95 (d, J = 9.1 Hz, 1H), 7.15 (d, J = 9.1 Hz, 1H), 7.13 (s, 1H),
Hz, 1H), 7.94 (d, J = 6.4 Hz, 1H), 7.77 (dd, J = 7.6, 8.0 Hz, 1H), 7.70 (dd, J 6.84 (d, J = 8.1 Hz, 1H), 3.42 (s, 2H), 2.38 (s, 3H); 13C NMR (151 MHz,
= 7.5, 7.6 Hz, 1H), 7.64 (dd, J = 7.5, 7.4 Hz, 1H), 7.47–7.38 (m, 2H); 13C CDCl3) δ 142.15, 134.74, 132.22, 131.54, 131.25, 131.01, 129.64, 129.18,
NMR (151 MHz, CDCl3) δ 140.92, 138.76, 137.25, 135.33, 134.26, 132.36, 128.23, 127.89, 127.84, 127.67, 127.56, 126.64, 126.24, 125.65, 125.34,
130.96, 130.44, 128.43, 128.33, 127.82, 127.69, 127.26, 127.03, 123.39, 125.28, 125.25, 125.15, 125.02, 115.78, 20.74; IR (neat): νmax = 3465,
122.15, 121.89, 121.74, 121.61, 119.78; IR (neat): νmax = 2983, 1736, 3374, 3039, 1602, 1498, 1292, 847, 721 cm-1; HRMS m/z (EI) calc. for
1235, 1044, 777, 744, 735 cm-1; Rf 0.45 (hex/EtOAc, 20/1).
C23H17N [M+] 307.1361, found 307.1363; Rf 0.39 (hex/EtOAc, 4/1).
o
10-methylbenzo[e]acephenanthrylene (2b).19 Light yellow solid (73 mg, 4-chloro-2-(pyren-1-yl)aniline (6c). Light yellow solid; m. p. 113–114 C;
55%); 1H NMR (600 MHz, CDCl3) δ 8.66 (d, J = 8.0 Hz, 1H), 8.43 (d, J = 1H NMR (600 MHz, CDCl3) δ 8.24 (d, J = 7.8 Hz, 1H), 8.23 (d, J = 7.7 Hz,
8.1 Hz, 1H), 8.19 (s, 1H), 8.04 (d, J = 7.9 Hz, 1H), 7.93 (d, J = 7.0 Hz, 1H), 1H), 8.19 (d, J = 7.5 Hz, 1H), 8.13 (d, J = 8.9 Hz, 1H), 8.11 (d, J = 8.9 Hz,
7.82 (s, 1H), 7.81 (d, J = 7.7 Hz, 1H), 7.76–7.73 (m, 1H), 7.68 (dd, J = 8.0, 1H), 8.06–8.02 (m, 2H), 7.94 (d, J = 7.7 Hz, 1H), 7.89 (d, J = 9.1 Hz, 1H),
7.9 Hz 1H), 7.63 (dd, J = 8.0, 8.1 Hz, 1H), 7.24 (d, J = 7.6 Hz, 1H), 2.52 (s, 7.33–7.27 (m, 2H), 6.80 (d, J = 8.4 Hz, 1H), 3.51 (s, 2H); 13C NMR (151
3H); 13C NMR (151 MHz, CDCl3) δ 138.80, 138.16, 137.38, 137.16, 135.22, MHz, CDCl3) δ 143.36, 132.94, 131.46, 131.34, 131.22, 131.13, 129.01,
134.03, 132.30, 130.74, 130.15, 128.91, 128.18, 127.55, 126.93, 126.71, 128.86, 128.24, 127.96, 127.83, 127.46, 126.37, 125.57, 125.46, 125.31,
123.14, 122.68, 121.23, 121.18, 121.10, 119.12, 21.80; IR (neat): νmax
2922, 2853, 1734, 1458, 1375, 773, 741 cm-1; Rf 0.47 (hex/EtOAc, 20/1).
=
125.10, 124.88, 123.08, 116.61; IR (neat): νmax = 3343, 3382, 3039, 1611,
1484, 1290, 845, 811, 726 cm-1; HRMS m/z (EI) calc. for C22H14ClN [M+]
327.0815, found 327.0816; Rf 0.43 (hex/EtOAc, 4/1).
10-chlorobenzo[e]acephenanthrylene (2c)
+ 12-chlorobenzo[e]ace-
phenanthrylene (2ci). Light yellow solid (28 mg, 20%); 1H NMR (600 MHz, indeno[1,2,3-cd]pyrene (7a).20 Yellow solid (117 mg, 85%); 1H NMR (600
CDCl3) δ 8.63 (d, J = 8.2 Hz, 1H), 8.61 (d, J = 8.1 Hz, 1H), 8.47 (d, J = 6.7 MHz, CDCl3) δ 8.54 (s, 1H), 8.38 (d, J = 7.4 Hz, 1H), 8.34 (d, J = 7.5 Hz,
Hz, 1H), 8.45 (d, J = 7.5 Hz, 1H), 8.40 (d, J = 8.1 Hz, 1H), 8.15 (s, 1H), 1H), 8.25 (d, J = 7.7 Hz, 1H), 8.21 (d, J = 7.7 Hz, 1H), 8.11 (d, J = 8.4 Hz,
8.10 (s, 1H), 8.01 (d, J = 8.0 Hz, 1H), 7.99 (d, J = 7.9 Hz, 1H), 7.89 (d, J = 2H), 8.07–8.03 (m, 2H), 8.02 (d, J = 6.7 Hz, 1H), 7.48 (dd, J = 7.3, 7.4 Hz,
6.7 Hz, 1H), 7.87 (s, 1H), 7.85 (d, J = 7.3 Hz, 1H), 7.77 (dd, J = 7.7, 7.6 Hz, 1H), 7.44 (dd, J = 7.3, 7.5 Hz, 1H); 13C NMR (151 MHz, CDCl3) δ 142.09,
1H), 7.76 (d, J = 7.9 Hz, 1H), 7.72 (dd, J = 7.6, 7.5 Hz, 1H), 7.70 (dd, J = 139.23, 135.92, 133.30, 132.25, 130.89, 130.84, 130.66, 128.76, 128.47,
6.8, 6.7 Hz, 1H), 7.69 (dd, J = 7.4, 7.3 Hz, 1H), 7.64 (dd, J = 7.7, 7.6 Hz,
127.38, 127.04, 127.02, 126.88, 126.73, 125.07, 123.44, 122.73, 121.96,
1H), 7.63 (dd, J = 7.0, 6.9 Hz, 1H), 7.37 (d, J = 8.0 Hz, 1H), 7.36 (d, J = 7.9 121.76, 121.62, 119.84; IR (neat): νmax = 2984, 1735, 1445, 1372, 1237,
Hz, 1H), 7.31 (dd, J = 7.6, 7.5 Hz, 1H); 13C NMR (151 MHz, CDCl3) δ 1043, 841, 730 cm-1; Rf 0.42 (hex/EtOAc, 20/1).
140.79, 140.24, 139.14, 137.44, 136.13, 135.80, 134.14, 134.04, 133.95,
133.84, 133.38, 132.25, 132.01, 131.04, 131.03, 130.57, 130.45, 130.26,
129.30, 128.53, 128.47, 128.28, 128.05, 127.77, 127.60, 127.53, 127.11,
127.05, 123.74, 123.34, 122.45, 122.47, 122.36, 122.30, 122.02, 120.20,
119.82 (overlapped peaks present); IR (neat): νmax = 3071, 2926, 1598,
1446, 903, 733 cm-1; HRMS m/z (EI) calc. for C20H11Cl [M+] 286.0549,
found 286.0550; Rf 0.65 (hex/EtOAc, 10/1).
9-methylindeno[1,2,3-cd]pyrene (7b). Yellow solid (102 mg, 70%); m. p.
154–156 oC; 1H NMR (600 MHz, CDCl3) δ 8.50 (s, 1H), 8.38 (d, J = 7.5 Hz,
1H), 8.33 (d, J = 7.7 Hz, 1H), 8.24 (d, J = 7.5 Hz, 1H), 8.21 (d, J = 7.7 Hz,
1H), 8.12 (d, J = 9.0 Hz, 1H), 8.06 (d, J = 9.0 Hz, 1H), 8.03 (dd, J = 7.6, 7.5
Hz, 1H), 7.99 (d, J = 7.6 Hz, 1H), 7.84 (s, 1H), 7.24 (d, J = 7.5 Hz, 1H),
2.55 (s, 3H); 13C NMR (151 MHz, CDCl3) δ 142.37, 138.56, 136.65, 136.03,
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Organic & Biomolecular Chemistry
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ARTICLE
Journal Name
133.41, 132.38, 131.28, 130.81, 130.66, 128.61, 127.82, 127.36, 126.87,
126.81, 126.72, 125.01, 123.34, 122.63, 122.48, 122.01, 120.99, 119.72,
22.18; IR (neat): νmax = 3038, 2919, 1617, 1455, 904, 831, 740 cm-1; Rf
0.40 (hex/EtOAc, 20/1).
2
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T. P. Goncalves, Q. Qi, X. Shi, H. Yamada, K. W. Huang,
9-chloroindeno[1,2,3-cd]pyrene (7c). Yellow solid (28 mg, 18%); IR
(neat): νmax = 3037, 2926, 1739, 1373, 1230, 1217, 844 cm-1; HRMS m/z
(EI) calc. for C22H11Cl [M+] 310.0549, found 310.0552; Rf 0.60 (hex/EtOAc,
10/1).
2-(naphthalen-1-yl)aniline (8).21 White solid; 1H NMR (600 MHz, CDCl3) δ
7.95 (d, J = 8.2 Hz, 1H), 7.92 (d, J = 8.3 Hz, 1H), 7.71 (d, J = 8.4 Hz, 1H),
7.61–7.57 (m, 1H), 7.54 (dd, J = 8.3, 8.2 Hz, 1H), 7.49 (d, J = 6.9 Hz, 1H),
7.48–7.44 (m, 1H), 7.30 (dd, J = 7.7, 7.4 Hz, 1H), 7.21 (d, J = 7.4 Hz, 1H),
6.95–6.90 (m, 1H), 6.86 (d, J = 8.0 Hz, 1H), 3.49 (s, 2H); 13C NMR (151
MHz, CDCl3) δ 144.52, 137.16, 134.01, 131.87, 131.39, 128.95, 128.50,
128.16, 127.77, 126.44, 126.23, 126.20, 126.06, 126.00, 118.49, 115.48;
IR (neat): νmax = 3468, 3379, 3056, 1614, 1495, 1297, 779, 751 cm-1; Rf
0.43 (hex/EtOAc, 4/1).
3
4
J. Ding, D. Kim and J. Wu, J. Am. Chem. Soc., 2016, 138
1065.
,
fluoranthene (9).22 White solid (66 mg, 65%); 1H NMR (600 MHz, CDCl3)
δ 7.96 (d, J = 7.0 Hz, 2H), 7.94 (dd, J = 5.8, 2.8 Hz, 2H), 7.86 (d, J = 8.1
Hz, 2H), 7.66 (dd, J = 8.1, 7.0 Hz, 2H), 7.41 (dd, J = 5.8, 2.8 Hz, 2H); 13C
NMR (151 MHz, CDCl3) δ 139.65, 137.17, 132.60, 130.20, 128.15, 127.74,
126.84, 121.73, 120.25; IR (neat): νmax = 3051, 1453, 1426, 910, 774, 746,
734 cm-1; Rf 0.36 (hex/EtOAc, 100/1).
5
6
7
(a) C. L. Eversloh, Y. Avlasevich, C. Li and K. Mullen,
Chem. Eur. J., 2011, 17, 12756; (b) L. M. Geary, T. Y.
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Chem., 1994, 59, 1294; (b) T. Takeda, K. Inukai, K.
Tahara and Y. Tobe, J. Org. Chem., 2011, 76, 9116; (c) F.
2-(isoquinolin-4-yl)aniline (10).23 Dark brown solid; 1H NMR (600 MHz,
CDCl3) δ 9.27 (s, 1H), 8.50 (s, 1H), 8.03 (d, J = 8.1 Hz, 1H), 7.69–7.60 (m,
3H), 7.29 (dd, J = 7.9, 7.7 Hz, 1H), 7.15 (d, J = 7.5 Hz, 1H), 6.89 (dd, J =
7.5, 7.4 Hz, 1H), 6.84 (d, J = 7.9 Hz, 1H), 3.53 (s, 2H); 13C NMR (151 MHz,
CDCl3) δ 152.57, 144.84, 143.84, 134.59, 131.60, 130.85, 130.55, 129.62,
Xu, L. Peng, A. Orita and J. Otera, Org. Lett., 2012, 14
3970.
,
(a) M. Grzybowski, K. Skonieczny, H. Butenschon and D.
T. Gryko, Angew. Chem. Int. Ed., 2013, 52, 9900; (b) A.
Naibi Lakshminarayana, J. Chang, J. Luo, B. Zheng, K. W.
Huang and C. Chi, Chem. Commun., 2015, 51, 3604.
O. Allemann, S. Duttwyler, P. Romanato, K. K. Baldridge
and J. S. Siegel, Science, 2011, 332, 574.
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Amsharov and P. Merz, J. Org. Chem., 2012, 77, 5445.
128.62, 128.08, 127.61, 125.30, 122.06, 118.61, 115.66; IR (neat): νmax
=
3327, 3201, 3027, 1614, 1489, 1455, 1299, 901, 747 cm-1; Rf 0.30
(hex/EtOAc, 1/1).
8
9
2-(benzo[b]thiophen-3-yl)aniline (13).24 Brown sticky oil; 1H NMR (600
MHz, CDCl3) δ 7.97 (d, J = 7.6 Hz, 1H), 7.69 (d, J = 7.5 Hz, 1H), 7.47 (s,
1H), 7.45–7.38 (m, 2H), 7.31–7.25 (m, 2H), 6.91 (dd, J = 7.5, 7.4 Hz, 1H),
6.85 (d, J = 7.9 Hz, 1H), 3.70 (s, 2H); 13C NMR (151 MHz, CDCl3) δ 144.82,
140.46, 138.33, 135.05, 131.25, 129.19, 124.82, 124.68, 124.40, 123.55,
122.94, 121.05, 118.39, 115.64; IR (neat): νmax = 3465, 3373, 3057, 1612,
1482, 1449, 1297, 906, 729 cm-1; Rf 0.50 (hex/EtOAc, 4/1).
10 (a) X. Wang, G. D. Cuny and T. Noel, Angew. Chem. Int.
Ed. Engl., 2013, 52, 7860; (b) D. Kundu, S. Ahammed
and B. C. Ranu, Org. Lett., 2014, 16, 1814; (c) M.
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Chatterjee, M. G. Choi, J. Kim, S. K. Chang and E. J. Cho,
Chem. Commun., 2016, 52, 4203.
3-phenylbenzo[b]thiophene (15).25 Yellow oil; 1H NMR (300 MHz, CDCl3)
δ 8.01–7.85 (m, 2H), 7.65–7.54 (m, 2H), 7.50–7.43 (m, 2H), 7.44–7.31 (m,
4H).
11 In the sense that diazonium intermediate is formed in
situ, our approach is similar to that of the Rapoport
group where indeno [1,2,3-jk]-fluorenes were
generated from 9-o-aminophenylfluorenes despite low
yield (5%), see: H. Rapoport and G. Smolinsky, J. Am.
Chem. Soc., 1960, 82, 934.
Acknowledgements
This research was supported by the Chung-Ang University
research grants in 2015 and the National Research Foundation
of Korea [NRF-2014-011165].
Notes and references
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6 | J. Name., 2012, 00, 1-3
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14 A possible reaction between tBuONO and molecular
ARTICLE
View Article Online
oxygen, see; T. Taniguchi, A. Yajima and H. Ishibashia,
Adv. Synth. Catal., 2011, 353, 2643.
DOI: 10.1039/C6OB01235C
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DOI: 10.1039/C6OB01235C
Cyclopenta-fused polycyclic aromatic hydrocarbons were synthesized from readily available 2-aryl-substituted
anilines under extremely mild conditions.