Synthesis of a macrocycle bearing a carbon framework of [16]Cyclophenacene as a Carbon Nanobelt

Article abstract of DOI:10.1021/acs.joc.9b01671

A synthetic pathway to a functionalized tetrahydro[5]phenacene was developed, which served as a precursor, leading to a dehydrobenzo[32]annulene macrocycle containing four carbon-carbon triple bonds. The high efficiency of the macrocyclization step can be

Full text of DOI:10.1021/acs.joc.9b01671

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Note
Synthesis of a Macrocycle Bearing a Carbon Framework
of [16]Cyclophenacene as a Carbon Nanobelt
Shuangjiang Li, and Kung K. Wang
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.9b01671 • Publication Date (Web): 29 Jul 2019
Downloaded from pubs.acs.org on July 29, 2019
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The Journal of Organic Chemistry
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Synthesis of a Macrocycle Bearing a Carbon Framework of [16]Cyclo-
phenacene as a Carbon Nanobelt
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Shuangjiang Li and Kung K. Wang*
C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, 26506-6045, United
States
Supporting Information Placeholder
ABSTRACT: A synthetic pathway to a functionalized tetrahydro[5]phenacene was developed, which served as a precursor leading
to a dehydrobenzo[32]annulene macrocycle containing four carbon‒carbon triple bonds. The high efficiency of the macrocyclization
step can be attributed to the structural rigidity of its immediate precursor. Hydrogenation of the four carbon‒carbon triple bonds
produced a macrocycle bearing a carbon framework of [16]cyclophenacene as the shortest macrocyclic belt-like structure of an
(8,8)armchair carbon nanotube.
Dehydrobenzoannulenes (DBAs) continue to attract consider-
able attention due in part to their interesting chemical reactivi-
ties and physical properties for a variety of potential materials
applications.1 Several synthetic methods for DBAs have been
developed. The relatively high efficiency of the macrocycliza-
tion step can be attributed to the structural rigidity of the pre-
cursors leading to DBAs. For example, macrocyclization of 1
was reported to produce hexadehydrotribenzo[12]annulenes 2
in 16 to 48% yields and octadehydrotetrabenzo[16]annulenes 3
in 8 to 16% yields (Scheme 1).2a-b Alternative synthetic routes
and reaction conditions for hexadehydrotribenzo[12]annulenes
were also reported.2c-j
Our interest in DBAs stems from the possibility of construct-
ing these macrocycles possessing carbon frameworks repre-
sented on armchair carbon nanotubes.3 The use of DBAs to pre-
pare benzoannulenes as potential precursors for the construc-
tion of macrocyclic belt-like structures (carbon nanobelts) was
recognized previously.4 Dehydrobenzo[32]annulene 4 contain-
ing four carbon‒carbon triple bonds was selected as the initial
target molecule having two extended tetrahydro[5]phenacene
systems to replace two benzene units in 3 to test the validity this
synthetic strategy (Figure 1). We were successful in developing
a synthetic pathway leading to 4, which was then hydrogenated
to give macrocycle 5.
Scheme 1. Synthesis of Hexadehydrotribenzo[12]annulenes
2 and Octadehydrotetrabenzo[16]annulenes 3
The formation of four additional carbon‒carbon bonds, de-
picted in red, of 5 could lead to 6 and, after dehydrogenation by
oxidative aromatization, 7 bearing a [16]cyclophenacene
([16]CPA) unit as a carbon nanobelt.5 The structure of [16]CPA
represents the shortest macrocyclic belt-like structure of an
(8,8)armchair carbon nanotube. Recently, synthetic pathways
leading to three carbon nanobelts, including [12]-, [16]-, and
[24]carbon nanobelts as isomers of [12]-, [16]-, and [24]CPAs,
respectively, were reported.5a,b Synthetic pathways for an arm-
chair and a chiral carbon nanobelts with carbon frameworks
represented on the sidewalls of a (12,12)- and a (18,12)carbon
nanotubes, respectively, were also reported.6 The belt-like
structures of CPAs can be constructed by fusing together two
units of the corresponding cycloparaphenylene (CPP), which
consists of a set of para-connected benzene rings in a cyclic
array. Unlike CPPs, each set of CPP in CPAs has two connec-
tions between the adjacent benzene rings. It is anticipated that
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CPAs would be thermally more robust, making them more suit-
butadiene 12 in 54% isolated yield over two steps from 10.
Diene 12 had very low solubility in common organic solvents,
and it was necessary to record its H NMR spectrum in CDCl3
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able in serving as templates for growing carbon nanotubes of a
single diameter and chirality,7 two factors of critical importance
for nanotechnology applications.8
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at 60 °C. The Diels‒Alder reaction between 12 and dibutyl acet-
ylenedicarboxylate11 at 150 °C for 20 h produced 13, which
upon treatment with 2,3-dichloro-5,6-dicyano-1,4-benzoqui-
none (DDQ) for oxidative aromatization gave a functionalized
and tetrahydrogenated derivative of [5]phenacene 14 in 54%
isolated yield over two steps from 12. It is noteworthy that an
excess of dibutyl acetylenedicarboxylate was needed to drive
the Diels‒Alder reaction toward 13. It was also important to
carefully control the reaction time and temperature to obtain op-
timal yield because diene 12 was prone to double-bond isomer-
ization to form a 1,4-dihydronaphthyl system and oxidative aro-
matization to form a naphthyl system.
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Scheme 2. Synthesis of Tetrahydro[5]phenacene 14
The synthetic sequence also required the preparation of
diacetylene 16, which was obtained via stannylation of the
terminal acetylene in 2-ethynyl-1-[(triisopropylsilyl)ethynyl]
benzene (15)12 with Me3SnNMe2,13 a combined base and
trimethylstannyl-group transfer reagent (Scheme 3). After 12 h
at 60 °C, all volatiles of the reaction mixture were removed in
vacuo, and the crude 16 was used without further purification.
Figure 1. Structures of macrocycles 4 to 6 and [16]CPA 7.
The first stage of the synthetic pathway leading to 5 involved
the preparation of functionalized tetrahydro[5]phenacene 14
(Scheme 2). Selective bromination of 8 gave 9 in 85% yield as
reported previously.9 Diketone 10 was successfully synthesized
via an iron-promoted oxidative coupling of the enolate of 9 in
69% isolated yield.10 It is noteworthy that the enolate coupling
reaction promoted by [Fe(DMF)3Cl2][FeCl4]10b appears to be
Scheme 3. Synthesis of Diacetylene 16
more
efficient
than
by
FeCl3.
In
addition,
[Fe(DMF)3Cl2][FeCl4] is not hygroscopic and is stable to water,
making it easier to handle when compared to hygroscopic
FeCl3.10 Reduction of 10 with sodium borohydride followed by
methanol produced diol 11, which was used without further pu-
rification due to its limited solubility in common organic sol-
vents and the formation of various stereoisomers. The crude
mixture of diol 11 was then treated with PBr3 to provide 1,3-
The next stage of the synthetic sequence involved the Migita‒
Kosugi‒Stille cross-coupling reactions between 14 and 2 equiv
of 16 (Scheme 4). After screening several palladium catalysts,
ligands, and solvents, the Pd-Sphos-dioxane catalytic system14
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The Journal of Organic Chemistry
was found to be most efficient for the cross-coupling reaction
prepare 5-bromo-6-methoxy-1,2,3,4-tetrahydronaphthalen-1-
one (9),9 [Fe(DMF)3Cl2][FeCl4],10b dibutyl acetylenedicarbox-
ylate,11 and 2-ethynyl-1-[(triisopropylsilyl)ethynyl]benzene
(15).12 Chemical shifts of NMR spectra were reported as parts
per million (δ) relative to the signal of CHCl3 at 7.26 ppm for
1H NMR spectra and center line signal of the CDCl3 triplet at
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3
4
5
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between the sterically hindered 14 and 16 in producing 17 in
93% isolated yield. Desilylation of 17 with tetrabutylammo-
nium fluoride (TBAF) then gave 18 in 91% isolated yield.
Treatment of 18 with Me3SnNMe2 produced the stannylated
product 19. The palladium-catalyzed Migita‒Kosugi‒Stille
cross-coupling reactions between 14 and 19 was again
successful in producing dehydrobenzo[32]annulene 4 in 53%
isolated yield over two steps from 18. The structural rigidity of
the immediate precursor leading to 4 with limited freedom of
rotation likely contributed to the relatively high efficiency of
the macrocyclization step. Catalytic hydrogenation of 4 with
Pd/C at room temperature afforded macrocycle 5 in 95%
isolated yield.
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77.0 ppm for 13C{1H} NMR spectra. H NMR spectra and
13C{1H} NMR spectra were recorded at 400 and 100 MHz, re-
spectively. Infrared (IR) spectra of solid samples were recorded
on a Fourier transform infrared system equipped with a dia-
mond crystal attenuated total reflectance sampling interface.
HRMS spectra were obtained on an Orbitrap mass analyzer cou-
pled with electrospray ionization (ESI).
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Experimental Procedure for Dibromide 10. To a solution of
freshly prepared LDA (14.9 mmol) in THF (20 mL) at −78 °C
was added 97 (3.61g, 14.2 mmol) in THF (20 mL) dropwise.
After 30 min at −78 °C, a solution of [Fe(DMF)3Cl2][FeCl4]10b
(3.86 g, 7.10 mmol) in 20 mL of DMF under argon was added
slowly. The reaction mixture was then warmed to rt. After 12 h,
the reaction mixture was quenched with 100 mL of a 1 M aque-
ous HCl solution. After 30 min of stirring, the reaction mixture
was filtered and then washed sequentially with water, ethanol,
and hexanes to give 10 (2.50 g, 4.92 mmol, 69% yield) as a
Scheme 4. Synthesis of Macrocycles 4 and 5
1
white solid: IR 1671, 1586, 1277 cm−1; H NMR (CDCl3, 400
MHz) δ 8.10 and 8.07 (2 H, two doublets from the two diastere-
omers, J = 9.0 Hz), 6.90 (2 H, two doublets from the two over-
lapping diastereomers, J = 9.0 Hz), 3.98 (6 H, s), 3.53‒2.88 (6
H, m), 2.16‒1.93 (4 H, m); 13C{1H} NMR (CDCl3, 100 MHz) δ
197.0, 195.9, 159.8, 159.7, 145.3, 144.8, 128.8, 128.6, 127.7,
127.6, 113.0, 112.8, 109.8, 109.6, 56.5, 47.7, 46.3, 30.5, 30.0,
24.74, 24.66; HRMS (ESI) m/z [M + H]+ calcd for C22H21Br2O4
506.9801, 508.9781, 510.9760; found 506.9833, 508.9812,
510.9794.
Experimental Procedure for 11. To a 200-mL flask were added
2.50 g of 10 (4.92 mmol) and 1.70 g of sodium borohydride
(44.9 mmol). The flask was flushed with argon before 100 mL
of THF was introduced via cannula. The reaction mixture was
heated at reflux for 1 h before 6 mL of methanol was added
dropwise. The reaction mixture was heated at reflux for an ad-
ditional 12 h before it was cooled to rt. Then the reaction mix-
ture was quenched with 50 mL of a 3.0 M sodium hydroxide
solution. After 10 minutes of stirring, the reaction mixture was
filtered and then washed with 20 mL of a 3.0 M sodium hydrox-
ide solution and water (20 mL). After the product was air dried,
the crude 11 (2.4 g) was obtained as a white solid, which was
used without further purification.
In summary, a synthetic pathway leading to macrocycle 5 bear-
ing a carbon framework of [16]CPA as the shortest macrocyclic
belt-like structure of an (8,8)armchair carbon nanotube has been
developed. The use of [Fe(DMF)3Cl2][FeCl4], instead of hygro-
scopic FeCl3, to promote the coupling reaction of the enolate of
9 was operationally easier to perform. The macrocyclization
step leading to dehydrobenzo[32]annulene 4 is relatively effi-
ciently, presumably due to the structural rigidity of its immedi-
ate precursor with limited freedom of rotation. Hydrogenation
of 4 then produced macrocycle 5. The methoxy groups in 5 pro-
vide potential handles for converting it to 6 and subsequently,
after oxidative aromatization, 7 containing a [16]CPA in its
structure. We are developing synthetic pathways to transform 5
and related macrocycles to the corresponding carbon nanobelts.
Experimental Procedure for 12. To a 20-mL vial were added
0.300 g of 11. The vial was capped with a rubber septum and
flushed with argon, and then 10 mL of dichloromethane was
introduced by a syringe. The reaction mixture was stirred at 0
°C for 5 min before phosphorus tribromide (0.18 mL, 1.9 mmol)
was added, and the mixture was warmed to rt. After 2 h of stir-
ring, the reaction mixture was filtered, washed with dichloro-
methane, a sodium hydroxide solution, water, and acetone to
give 12 (0.158 g, 0.33 mmol, 54% yield from 10) as a white
EXPERIMENTAL SECTION
General Experimental Methods. All reactions were con-
ducted in oven-dried (120 °C) glassware under an argon atmos-
phere. Oil bath was used as the heat source for the reactions that
required heating. Chemicals, including 6-methoxy-1,2,3,4-tet-
rahydronaphthalen-1-one (8), 2,3-dichloro-5,6-dicyano-1,4-
1
solid: IR 1588, 1475, 1264, 1074 cm−1; H NMR (CDCl3, 400
MHz, 60 °C) δ 7.02 (2 H, d, J = 8.2 Hz), 6.74 (2 H, d, J = 8.2
Hz), 6.61 (2 H, s), 3.90 (6 H, s), 3.07 (4 H, t, J = 8.0 Hz), 2.66
(4 H, t, J = 7.8 Hz); HRMS (ESI) m/z [M + H]+ calcd for
C22H21Br2O2 474.9903, 476.9882, 478.9862; found 474.9905,
476.9887, 478.9867.
benzoquinone
(Me3SnNMe2),
[Pd2(dba)3],
(DDQ), (dimethylamino)trimethylstannane
tris(dibenzylideneacetone)dipalladium
dicyclohexyl[2',6'-dimethoxy(1,1'-biphenyl)-2-
yl]phosphine (Sphos), and tetrabutylammonium fluoride
(TBAF, 1.0 M in THF) were purchased from chemical suppliers
and were used as received. Reported procedures were used to
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Experimental Procedure for 13. To a mixture of 1,3-butadiene
Page 4 of 6
Experimental Procedure for 18. To a solution of 17 (0.601 g,
0.545 mmol) in THF (5 mL) at 0 °C was added a solution of
TBAF (1.0 M in THF, 1.36 mL, 1.36 mmol). The reaction mix-
ture was then warmed to rt and stirred for 14 h. A saturated
aqueous NaHCO3 solution (5.0 mL) was added, and the mixture
was poured into water (10 mL) and extracted with dichloro-
methane (3 × 10 mL). The combined organic layers were dried
over sodium sulfate. Solvents were evaporated in vacuo, and the
crude residue was purified by flash column chromatography
(silica gel/dichloromethane:hexanes = 90:10) to produce 18
(0.391 g, 0.494 mmol, 91% yield) as a white solid: IR 3281,
1718, 1272 cm−1; 1H NMR (CDCl3, 400 MHz) δ 7.62 (2 H, d, J
= 7.4 Hz), 7.55 (2 H, d, J = 7.4 Hz), 7.44 (2 H, d, J = 8.6 Hz),
7.35 (2 H, t, J = 7.4 Hz), 7.29 (2 H, t, J = 7.4 Hz), 6.79 (2 H, d,
J = 9.0 Hz), 4.22 (4 H, t, J = 6.7 Hz), 3.95 (6 H, s), 3.35 (2 H,
s), 3.21 (4 H, t, J = 6.7 Hz), 2.82 (4 H, t, J = 6.3 Hz), 1.59 (4 H,
quintet, J = 7.2 Hz), 1.27 (4 H, sextet, J = 7.3 Hz), 0.88 (6 H, t,
J = 7.4 Hz); 13C{1H} NMR (CDCl3, 100 MHz) δ 170.4, 160.0,
143.2, 138.1, 132.6, 132.0, 131.3, 128.57, 128.53, 128.1, 127.8,
126.8, 126.4, 124.2, 110.8, 108.3, 96.0, 88.3, 82.7, 81.0, 65.7,
56.0, 30.2, 26.8, 25.9, 19.0, 13.7; HRMS (ESI) m/z [M]+ calcd
for C54H46O6 790.3289, 791.3323; found 790.3301, 791.3334.
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8
12 (0.206 g, 0.433 mmol) and an excess of dibutyl acetylenedi-
carboxylate9 (0.500 g, 2.21 mmol) in a pressure vessel glass
tube was added 2 mL of dry chlorobenzene under argon. The
reaction mixture was stirred at 150 °C for 20 h before it was
cooled to rt. The reaction mixture including the insoluble mate-
rials was filtered and washed with 5 mL of dichloromethane.
Solvents were evaporated in vacuo, and the crude residue of 13
was used without further purification.
Experimental Procedure for 14. To a 20-mL flask containing
the crude 13 was added 0.150 g (0.661 mmol) of DDQ. The
flask was flushed with argon, and then 6 mL of chlorobenzene
was introduced by a syringe. The reaction mixture was heated
at 70 °C for 1 h before it was cooled to rt. Dichloromethane (10
mL) was added, and the solution was passed through a basic
aluminum oxide column (4 cm high, 2.5 cm in diameter). The
column was eluted with an additional 100 mL of a mixture of
dichloromethane and ethyl acetate (1:1). Solvents were re-
moved in vacuo, and the residue was purified by flash column
chromatography (silica gel/dichloromethane:hexanes = 85:15)
to produce 14 (0.163 g, 0.233 mmol, 54% yield from 12) as a
white solid: IR 1738, 1725, 1276, 750 cm−1; 1H NMR (CDCl3,
400 MHz) δ 7.40 (2 H, d, J = 8.6 Hz), 6.79 (2 H, d, J = 8.6 Hz),
4.20 (4 H, t, J = 6.7 Hz), 3.93 (6 H, s), 3.03 (4 H, t, J = 6.5 Hz),
2.78 (4 H, t, J = 6.5 Hz), 1.58 (4 H, quintet, J = 7.0 Hz); 1.26 (4
H, sextet, J = 7.3 Hz), 0.86 (6 H, t, J = 7.4 Hz); 13C{1H} NMR
(CDCl3, 100 MHz) δ 170.2, 155.6, 140.3, 137.9, 131.3, 128.9,
127.7, 126.6, 112.8, 109.3, 65.8, 56.4, 30.2, 28.5, 25.9, 19.0,
13.7; HRMS (ESI) m/z [M]+ calcd for C34H36Br2O6 698.0873,
700.0853, 702.0832; found 698.0874, 700.0853, 702.0826.
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Experimental Procedure for 19. To a solution of 18 (0.380 g,
0.480 mmol) in THF (3 mL) was added (dimethylamino)trime-
thylstannane (0.40 mL, 2.4 mmol). The solution was heated to
60 °C for 16 h. All volatiles were then removed in vacuo to give
1
the crude 19, which was used without further purification: H
NMR (CDCl3, 400 MHz) δ 7.59 (2 H, d, J = 7.0 Hz), 7.52 (2 H,
d, J = 7.4 Hz ), 7.44 (2 H, d, J = 9.0 Hz), 7.29‒7.22 (4 H, m),
6.79 (2 H, t, J = 8.6 Hz), 4.22 (4 H, t, J = 6.5 Hz), 3.94 (6 H, s),
3.19 (4 H, t, J = 6.3 Hz), 2.80 (4 H, t, J = 6.5 Hz), 1.59 (4 H,
quintet, J = 7.1 Hz), 1.28‒1.23 (4 H, m), 0.87 (6 H, t, J = 7.2
Hz), 0.32 (18 H, s); 13C{1H} NMR (CDCl3, 100 MHz) δ 170.4,
159.9, 142.9, 137.9, 132.7, 132.2, 131.2, 128.5, 127.9, 127.7,
126.2, 126.0, 125.4, 110.9, 108.3, 107.6, 97.9, 96.6, 87.7, 67.0,
65.6, 56.0, 30.1, 26.8, 25.9, 19.0, 13.6, ‒7.6.
Experimental Procedure for 16. To a solution of 1510 (0.389 g,
1.38 mmol) in THF (3 mL) was added (dimethylamino)trime-
thylstannane (0.56 mL, 3.4 mmol). The solution was heated to
60 °C for 16 h, and then all volatiles were removed in vacuo to
give the crude 16, which was used without further purification:
1H NMR (CDCl3, 400 MHz) δ 7.48‒7.44 (2 H, m), 7.22‒7.18
(2 H, m), 1.15 (21 H, s), 0.34 (9 H, s); 13C{1H} NMR (CDCl3,
100 MHz) δ 132.73, 132.72, 127.8, 127.5, 126.1, 125.8, 107.1,
105.5, 97.8, 94.6, 18.8, 11.3, ‒7.7.
Experimental Procedure for 4. To a mixture of 14 (0.335 g,
0.478 mmol), tris(dibenzylideneacetone)dipalladium (0.034 g,
0.037 mmol), and Sphos ligand (0.068 g, 0.17 mmol) in a pres-
sure vessel glass tube was added 30 mL of dry dioxane under
argon. After 10 min of stirring, the crude 19 in 10 mL of dioxane
was added to the solution in the glass tube via cannula. The re-
action mixture was stirred at 120 °C for 12 h before it was
cooled to rt. Dioxane was evaporated in vacuo, and the residue
was purified by flash column chromatography (silica gel/di-
chloromethane:ethyl acetate = 98:2) to produce 4 (0.336 g,
0.253 mmol, 53% yield) as a white solid: IR 1736, 1710, 1273
cm−1; 1H NMR (CDCl3, 400 MHz) δ 7.65 (4 H, dd, J = 5.9, 3.5
Hz), 7.323 (4 H, d, J = 8.6 Hz), 7.322 (4 H, dd, J = 5.9, 3.5 Hz),
6.74 (4 H, d, J = 9.0 Hz), 4.18 (8 H, t, J = 6.8 Hz), 3.87 (12 H,
s), 3.05 (8 H, broad), 2.77 (8 H, broad multiplet), 1.57 (8 H,
quintet, J = 7.1 Hz), 1.27 (8 H, sextet, J = 7.6 Hz), 0.87 (12 H,
t, J = 7.2 Hz); 13C{1H} NMR (CDCl3, 100 MHz) δ 170.2, 160.1,
142.6, 137.4, 132.6, 131.2, 128.5, 128.1, 127.9, 125.9, 125.8,
110.8, 108.5, 96.3, 87.5, 65.7, 55.9, 30.2, 26.7, 26.4, 19.0, 13.7;
HRMS (ESI) m/z [M]+ calcd for C88H80O12 1328.5644,
1329.5678; found 1328.5671, 1329.5680.
Experimental Procedure for 17. To a mixture of 14 (0.410 g,
0.585 mmol), tris(dibenzylideneacetone)dipalladium (0.030 g,
0.033 mmol), and Sphos ligand (0.060 g, 0.15 mmol) in a pres-
sure vessel glass tube was added 20 mL of dry dioxane under
argon. After 10 min of stirring, the crude 16 in 10 mL of dioxane
was added to the solution in the glass tube via cannula. The re-
action mixture was stirred at 120 °C for 12 h before it was
cooled to rt. Dioxane was evaporated in vacuo, and the residue
was purified by flash column chromatography (silica gel/di-
chloromethane:hexanes = 90:10) to produce 17 (0.601 g, 0.545
mmol, 93% yield) as a white solid: IR 2156, 1717, 1271 cm−1;
1H NMR (CDCl3, 400 MHz) δ 7.59 (2 H, d, J = 7.4 Hz), 7.53 (2
H, d, J = 7.4 Hz), 7.43 (2 H, d, J = 8.6 Hz), 7.31‒7.24 (4 H, m),
6.76 (2 H, d, J = 8.6 Hz), 4.22 (4 H, t, J = 6.7 Hz), 3.90 (6 H,
s), 3.10 (4 H, t, J = 6.3 Hz), 2.76 (4 H, t, J = 6.3 Hz), 1.59 (4 H,
quintet, J = 7.3 Hz), 1.28 (4 H, sextet, J = 7.2 Hz), 1.06 (42 H,
s), 0.88 (6 H, t, J = 7.2 Hz); 13C{1H} NMR (CDCl3, 100 MHz)
δ 170.5, 160.0, 142.9, 138.1, 132.9, 132.5, 131.2, 128.6, 127.9,
127.8, 126.19, 126.14, 125.6, 111.0, 108.1, 105.6, 96.2, 95.0,
87.7, 65.7, 55.9, 30.2, 26.9, 25.9, 19.0, 18.6, 13.7, 11.3; HRMS
(ESI) m/z [M + H]+ calcd for C72H87Si2O6 1103.6036,
1104.6069; found 1103.6048, 1104.6078.
Experimental Procedure for 5. A mixture of 4 (0.100 g, 0.075
mmol), a Pd/C catalyst (0.050 g, 10% Pd on carbon), acetic acid
(1.0 mL), methanol (1.0 mL), and ethyl acetate (10 mL) was
stirred under a hydrogen atmosphere (25 psi) at rt. After 6 h, the
reaction mixture was filtered, and the filtrate was concentrated
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The Journal of Organic Chemistry
Y.; Yoshida, M. A One-Step Synthesis of Dehydro[12]annu-
in vacuo to give 5 (0.096 g, 0.071 mmol, 95% yield) as a white
solid: IR 1720, 1597, 1262 cm−1; 1H NMR (CDCl3, 400 MHz)
δ 7.36 (4 H, dd, J = 5.5, 3.5 Hz), 7.32 (4 H, d, J = 8.6 Hz ), 7.22
(4 H, dd, J = 5.5, 3.1 Hz), 6.76 (4 H, d, J = 8.6 Hz ), 4.17 (8 H,
t, J = 6.7 Hz), 3.87 (12 H, s), 3.02 (8 H, broad multiplet), 2.84
(16 H, two broad overlapping multiplets), 2.76 (8 H, broad mul-
tiplet), 1.55 (8 H, quintet, J = 7.1 Hz), 1.19 (8 H, sextet, J = 7.8
Hz), 0.83 (12 H, t, J = 7.4 Hz); 13C{1H} NMR (CDCl3, 100
MHz) δ 170.5, 157.4, 140.1, 138.0, 137.1, 131.9, 129.2, 128.7,
127.2, 126.14, 126.11, 125.8, 108.2, 65.5, 55.5, 32.5, 30.2, 27.9,
26.4, 25.2, 19.0, 13.7; HRMS (ESI) m/z [M]+ calcd for
C88H96O12 1344.6896, 1345.6930; found 1344.6901,
1345.6935.
lenes Using Palladium-Catalyzed Reaction of o-Diiodoarenes
with Acetylene Gas. Tetrahedron Lett. 1998, 39, 4701-4704. (f)
Kehoe, J. M.; Kiley, J. H.; English, J. J.; Johnson, C. A.; Pe-
tersen, R. C.; Haley, M. M. Carbon Networks Based on Dehy-
drobenzoannulenes. 3. Synthesis of Graphyne Substructures.
Org. Lett. 2000, 2, 969-972. (g) Li, Y.; Zhang, J.; Wang, W.;
Miao, Q.; She, X.; Pan, X. Efficient Synthesis of Tribenzohexa-
dehydro[12]annulene and Its Derivatives in the Ionic Liquid. J.
Org. Chem. 2005, 70, 3285-3287. (h) Huynh, C.; Linstrumelle,
G. A Short Route to Dehydro [12] Annulenes. Tetrahedron
1988, 44, 6337-6344. (i) Csékei, M.; Novák, Z.; Kotschy, A.
Ethynyl-Cyclohexanol: an Efficient Acetylene Surrogate in So-
nogashira Coupling. Tetrahedron 2008, 64, 975-982. (j) Peng,
L.; Xu, F.; Shinohara, K.; Nishida, T.; Wakamatsu, K.; Orita, A.;
Otera, J. Remarkable Electron-Withdrawing Effect of the
Ph2P(O)-Ethynyl Group: Ph2P(O)-Ethynyl-Substituted Aryl
Halides and Copper Acetylides for Tailor-Made Sonogashira
Couplings. Org. Chem. Front. 2015, 2, 248-252.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
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24
25
26
27
28
29
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31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ASSOCIATED CONTENT
Supporting Information
The Supporting Information is available free of charge on the ACS
Publications website at DOI:
(3) (a) Jasti, R.; Bhattacharjee, J.; Neaton, J. B.; Bertozzi, C. R. Syn-
thesis, Characterization, and Theory of [9]-, [12]-, and [18]Cy-
cloparaphenylene: Carbon Nanohoop Structures. J. Am. Chem.
Soc. 2008, 130, 17646-17647. (b) Leonhardt, E. J.; Van Raden,
J. M.; Miller, D.; Zakharov, L. N.; Aleman, B.; Jasti, R. A Bot-
tom-Up Approach to Solution-Processed, Atomically Precise
Graphitic Cylinders on Graphite. Nano. Lett. 2018, 18, 7991-
7997. (c) Takaba, H.; Omachi, H.; Yamamoto, Y.; Bouffard, J.;
Itami, K. Selective Synthesis of [12]Cycloparaphenylene. An-
gew. Chem., Int. Ed. 2009, 48, 6112-6116. (d) Segawa, Y.; Yagi,
A.; Matsui, K.; Itami, K. Design and Synthesis of Carbon Nano-
tube Segments. Angew. Chem., Int. Ed. 2016, 55, 5136-5158. (e)
Yamago, S.; Watanabe, Y.; Iwamoto, T. Synthesis of [8]Cyclo-
paraphenylene from a Square-Shaped Tetranuclear Platinum
Complex. Angew. Chem., Int. Ed. 2010, 49, 757-759. (f) Huang,
C.; Huang, Y.; Akhmedov, N. G.; Popp, B. V.; Petersen, J. L.;
Wang, K. K. Functionalized Carbon Nanohoops: Synthesis and
Structure of a [9]Cycloparaphenylene Bearing Three 5,8-Di-
methoxynaphth-1,4-diyl Units. Org. Lett. 2014, 16, 2672-2675.
(g) Li, S.; Huang, C.; Thakellapalli, H.; Farajidizaji, B.; Popp,
B. V.; Petersen, J. L.; Wang, K. K. Syntheses and Structures of
Functionalized [9]Cycloparaphenylenes as Carbon Nanohoops
Bearing Carbomethoxy and N-Phenylphthalimido Groups. Org.
Lett. 2016, 18, 2268-2271. (h) Huang, C.; Li, S.; Thakellapalli,
H.; Farajidizaji, B.; Huang, Y.; Akhmedov, N. G.; Popp, B. V.;
Petersen, J. L.; Wang, K. K. Synthesis of Partially Hydrogenated
Cycloparaphenylenes with Bent and Fused Structures Bearing
Armchair Carbon Nanotube-like Connections. J. Org. Chem.
2017, 82, 1166-1174. (i) Li, S.; Aljhdli, M.; Thakellapalli, H.;
Farajidizaji, B.; Zhang, Y.; Akhmedov, N. G.; Milsmann, C.;
Popp, B. V.; Wang, K. K. Synthesis and Structure of a Function-
alized [9]Cycloparaphenylene Bearing Three Indeno[2,1-a]flu-
orene-11,12-dione-2,9-diyl Units. Org. Lett. 2017, 19, 4078-
4081.
(4) (a) Sirinintasak, S.; Kuwatani, Y.; Hoshi, S.-i.; Isomura, E.;
Nishinaga, T.; Iyoda, M. Short-Step Syntheses and Complexa-
tion Properties of Z,Z-Tribenzodidehydro- and All-Z-
tribenzo[12]annulenes. Tetrahedron Lett. 2007, 48, 3433-3436.
(b) Iyoda, M.; Kuwatani, Y.; Nishinaga, T.; Takase, M.;
Nishiuchi, T. Conjugated Molecular Belts Based on 3D Benzan-
nulene Systems. In Fragments of Fullerenes and Carbon Nano-
tubes: Designed Synthesis, Unusual Reactions, and Coordina-
tion Chemistry; Petrukhina, M. A., Scott, L. T., Eds.; John Wiley
& Sons: Hoboken, NJ, 2012; Chapter 12, pp 311−342.
(5) (a) Povie, G.; Segawa, Y.; Nishihara, T.; Miyauchi, Y.; Itami, K.
Synthesis of a Carbon Nanobelt. Science 2017, 356, 172-175. (b)
Povie, G.; Segawa, Y.; Nishihara, T.; Miyauchi, Y.; Itami, K.
Synthesis and Size-Dependent Properties of [12], [16], and [24]
Carbon Nanobelts. J. Am. Chem. Soc. 2018, 140, 10054-10059.
(6) Cheung, K. Y.; Gui, S.; Deng, C.; Liang, H.; Xia, Z.; Liu, Z.;
Chi, L.; Miao, Q. Synthesis of Armchair and Chiral Carbon
Nanobelts. Chem 2019, 5, 838-847.
1H and/or 13C NMR spectra of all new compounds (PDF)
AUTHOR INFORMATION
Corresponding Author
*E-mail: kung.wang@mail.wvu.edu
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
This material is based upon work supported by the National Sci-
ence Foundation under CHE – 1464026 and CHE – 1853456.
The NMR spectrometer on which this work was carried out was
supported by the Major Research Instrumentation Program of
the NSF (CHE – 1228336).
REFERENCES
(1) (a) Takeda, T.; Haley, M. M. Synthesis and Photophysical Prop-
erties of Expanded Dehydrobenzoannulene Macrotricycles.
Can. J. Chem. 2017, 95, 298-302. (b) Spitler, E. L.; Johnson, C.
A., II; Haley, M. M. Renaissance of Annulene Chemistry. Chem.
Rev. 2006, 106, 5344-5386. (c) Lee, S.; Chenard, E.; Gray, D.
L.; Moore, J. S. Synthesis of Cycloparaphenyleneacetylene via
Alkyne Metathesis: C70 Complexation and Copper-Free Triple
Click Reaction. J. Am. Chem. Soc. 2016, 138, 13814-13817. (d)
Tahara, K.; Yamamoto, Y.; Gross, D. E.; Kozuma, H.; Arikuma,
Y.; Ohta, K.; Koizumi, Y.; Gao, Y.; Shimizu, Y.; Seki, S.;
Kamada, K.; Moore, J. S.; Tobe, Y. Syntheses and Properties of
Graphyne Fragments: Trigonally Expanded Dehydrobenzo[12]
annulenes. Chem. – Eur. J. 2013, 19, 11251-11260.
(2) (a) Solooki, D.; Ferrara, J. D.; Malaba, D.; Bradshaw, J. D.;
Tessier, C. A.; Youngs, W. J. Tribenzocyclyne (TBC) and Tetra-
benzocyclyne (QBC). Inorg. Synth. 1997, 31, 122-128. (b)
Zhang, D.; Tessier, C. A.; Youngs, W. J. Synthesis of Tris(2,5-
dialkynylthieno)cyclotriynes, Tris(4,5-dialkoxyphenyl)cyclotri-
ynes, and Tetrakis(4,5-dialkoxyphenyl)cyclotetraynes with
Long-Chain Alkyl Substituents, and the Nickel and Cobalt Com-
plexes of Tris[4,5-(didecyloxy)phenyl]cyclotriyne. Chem. Ma-
ter. 1999, 11, 3050-3057. (c) Iyoda, M.; Sirinintasak, S.;
Nishiyama, Y.; Vorasingha, A.; Sultana, F.; Nakao, K.; Ku-
watani, Y.; Matsuyama, H.; Yoshida, M.; Miyake, Y. Copper-
Mediated Simple and Efficient Synthesis of Tribenzohexadehy-
dro[12]annulene and Its Derivatives Synthesis 2004, 1527-1531.
(d) Miljanić, O. Š.; Vollhardt, K. P. C.; Whitener, G. D. An Al-
kyne Metathesis-Based Route to ortho-Dehydrobenzannulenes.
Synlett 2003, 29-34. (e) Iyoda, M.; Vorasingha, A.; Kuwatani,
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 6 of 6
(7) Omachi, H.; Nakayama, T.; Takahashi, E.; Segawa, Y.; Itami,
Activated Alkyne: Stereoselective Synthesis of 2-[(o-Methyl-
thio)aryloxy]-Substituted Dialkyl Maleates. J. Org. Chem. 2019,
84, 5846-5854.
K. Initiation of Carbon Nanotube Growth by Well-Defined Car-
bon Nanorings. Nat. Chem. 2013, 5, 572-576.
1
2
3
4
5
6
7
8
9
(8) Sanchez-Valencia, J. R.; Dienel, T.; Gröning, O.; Shorubalko, I.;
Mueller, A.; Jansen, M.; Amsharov, K.; Ruffieux, P.; Fasel, R.
Controlled Synthesis of Single-Chirality Carbon Nanotubes. Sci-
ence 2014, 512, 61-64.
(9) Pravst, I.; Zupan, M.; Stavber, S. Directed Regioselectivity of
Bromination of Ketones with NBS: Solvent-Free Conditions
Versus Water. Tetrahedron Lett. 2006, 47, 4707-4710.
(10) (a) Frazier, R. H., Jr.; Harlow, R. L. Oxidative Coupling of Ke-
tone Enolates by Ferric Chloride. J. Org. Chem. 1980, 45, 5408-
5411. (b) Tobinaga, S.; Kotani, E. Intramolecular and Intermo-
lecular Oxidative Coupling Reactions by a New Iron Complex
[Fe(DMF)3Cl2][FeCl4]. J. Am. Chem. Soc. 1972, 94, 309-310.
(11) H. Hazarika, H. ; Neog, K.; Sharma, A.; Das, B.; Gogoi, P.
Three-Component Coupling Reactions of Aryne, DMSO, and
(12) Bell, M. L.; Chiechi, R. C.; Johnson, C. A.; Kimball, D. B.;
Matzger, A. J.; Wan, W. B.; Weakley, T. J. R.; Haley, M. M. A
Versatile Synthetic Route to Dehydrobenzoannulenes via in situ
Generation of Reactive Alkynes. Tetrahedron 2001, 57, 3507-
3520.
(13) Tomaschautzky, J.; Neumann, B.; Stammler, H.-G.; Mitzel, N.
W. Poly-Lewis-Acids Based on Bowl-Shaped Tribenzotriquina-
cene. Dalton Trans. 2017, 46, 1112-1123.
(14) Naber, J. R.; Fors, B. P.; Wu, X.; Gunn J. T.; Buchwald, S. L.
Stille Cross-Coupling Reactions of Aryl Mesylates and Tosyl-
ates Using a Biarylphosphine Based Catalyst System. Heterocy-
cles 2010, 80. 1215-1226.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
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