Photochemical Synthesis and Electronic Properties of Extended Corannulenes with Variable Fluorination Pattern

Article abstract of DOI:10.1021/acs.joc.7b03146

The first family of extended and fluorinated corannulenes is prepared through a highly efficient and modular synthetic strategy. In this strategy, corannulene aldehyde could be combined with the fluorine-carrying phosphonium ylides to furnish stilbene-like vinylene precursors. A photochemically induced oxidative cyclization process of these precursors gives rise to the fluorinated and curved polycyclic aromatic hydrocarbons. A UV-vis absorption study shows that aromatic extension results in a bathochromic shift of about 12 nm. Fluorination further shifts the absorption spectrum to the red region, and a maximum shift of about 22 nm is detected for a compound carrying two trifluoromethyl groups. A cyclic and square-wave voltammetry investigation reveals that the extension of the corannulene scaffold increases the reduction potential by 0.11 V. Placement of fluorine or trifluoromethyl groups further enhances the electron affinities. In this regard, the presence of one trifluoromethyl group equals the effect of three aromatic fluorine atoms. Molecules with two trifluoromethyl groups, meanwhile, exhibit the highest reduction potentials of -1.93 and -1.83 V. These values are 0.37 and 0.46 V higher than those of the parental corannulene and demonstrate the utility of the present design concept by efficiently accessing effective electron acceptors based on the buckybowl motif.

Full text of DOI:10.1021/acs.joc.7b03146

Article
Cite This: J. Org. Chem. XXXX, XXX, XXX−XXX
pubs.acs.org/joc
Photochemical Synthesis and Electronic Properties of Extended
Corannulenes with Variable Fluorination Pattern
̂
,‡
†
†
†
†
́
Dzeneta Halilovic, Maja Budanovic, Zeng R. Wong, Richard D. Webster, June Huh,*
,
†,§
and Mihaiela C. Stuparu*
†Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University,
2
1-Nanyang Link, 637371, Singapore
‡
̂
Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Korea
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
§
*
S Supporting Information
ABSTRACT: The first family of extended and fluorinated corannulenes is prepared
through a highly efficient and modular synthetic strategy. In this strategy, corannulene
aldehyde could be combined with the fluorine-carrying phosphonium ylides to furnish
stilbene-like vinylene precursors. A photochemically induced oxidative cyclization
process of these precursors gives rise to the fluorinated and curved polycyclic aromatic
hydrocarbons. A UV−vis absorption study shows that aromatic extension results in a
bathochromic shift of about 12 nm. Fluorination further shifts the absorption spectrum
to the red region, and a maximum shift of about 22 nm is detected for a compound
carrying two trifluoromethyl groups. A cyclic and square-wave voltammetry
investigation reveals that the extension of the corannulene scaffold increases the
reduction potential by 0.11 V. Placement of fluorine or trifluoromethyl groups further
enhances the electron affinities. In this regard, the presence of one trifluoromethyl
group equals the effect of three aromatic fluorine atoms. Molecules with two
trifluoromethyl groups, meanwhile, exhibit the highest reduction potentials of −1.93
and −1.83 V. These values are 0.37 and 0.46 V higher than those of the parental corannulene and demonstrate the utility of the
present design concept by efficiently accessing effective electron acceptors based on the buckybowl motif.
INTRODUCTION
thus, is an established route to modulate the electronic
properties of the bowl-shaped aromatic nucleus.
■
6
Fluorinated corannulene derivatives have been known to be
good electron acceptors.
potential applications in the vast arena of organic electronics. In
this context, in 2012, Boltalina and co-workers showed that a
gas phase synthesis could be employed for the introduction of
five trifluoromethyl groups onto the corannulene scaffold.
However, harsh reaction conditions and a tedious purification
procedure coupled with a low yield of the final compound
15%) restrict wide applicability of such a synthetic protocol. In
the same year, the group of Lentz reported the synthesis of
1
−6
An alternative strategy to meet this goal is through extending
the aromatic area of the corannulene scaffold by annulation to
planar π-systems that are polycyclic. Siegel and co-workers have
established that such aromatic framework extensions can allow
This property, therefore, suggests
7
1
for the variation of such electronic properties. The final
molecules in this approach can be imagined as hybrids of planar
and nonplanar aromatic structures and are referred to as
“
extended corannulenes”. Besides Siegel’s hemicoronene-
(
corannulene structure, there are a few other examples in this
8
,9
regard. This includes corannulene hybrids with naphthalene,
anthracene, triphenylene, benzopyrene, and porphyrin.
corannulene carrying one, two, and three trifluoromethy2l
9
9
10
11,12
groups at predefined positions on the corannulene nucleus.
In most of these cases, distinct property changes are observed
in the corannulene nucleus upon its hybridization with the
In this case, the synthesis was in a solution phase and more
practical albeit still suffering from low overall yields. Very
recently, Baldridge and Siegel have shown that readily available
halocorannulene and corannuleneboronates can undergo
copper-mediated Hartwig/Yagupolskii coupling processes to
yield a variety of fluorinated corannulenes in moderate to good
13
planar unit.
We envisage that by combining the two aforementioned
motifs, hybridizing with a polycyclic planar π unit and
fluorinating of the aromatic scaffold into a single molecular
structure would provide a powerful route to new electronically
active corannulene materials. Our recently developed photo-
5
yields (up to 80% in some cases). A systematic structure−
property relationship development also suggested that each
trifluoromethyl group shifted the first reduction potential of the
corannulene nucleus by 0.22 V. Direct placement of electron
withdrawing substituents, such as the trifluoromethyl groups,
Received: December 14, 2017
©
XXXX American Chemical Society
A
DOI: 10.1021/acs.joc.7b03146
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
chemical synthesis would allow for a facile access to such
Having efficient access to aldehyde and ylide-based building
15,16
extended and fluorinated structures due to its high efficiency
blocks, the Wittig olefination
reaction was then carried out
8
and modularity. In this approach, a planar aromatic system of
to combine corannulene with the fluorinated flat aromatic
segment through a vinylene linkage. This process gave rise to
the stilbene-like precursors, 2a−j. Here, the isolated yields
ranged from 70 to 93% and column chromatography was
necessary to purify the products.
choice can be annulated to the nonplanar corannulene scaffold
in a two-step process. First, a vinylene linkage is established
between the two segments to be joined together. Next, a
photochemically induced oxidative−cyclization process fuses
the two aromatic structures together. In the present quest, the
planar structure can carry the fluorinated sites, provide the
targeted structures with synthetic ease, and would allow for
investigations into their electronic properties. This work,
therefore, examines the photochemical synthesis of the first
family of the extended corannulenes carrying a predefined
number, nature, and position of fluorinated sites and their
electrochemical and optical properties. Furthermore, a
theoretical investigation based on the DFT-calculations is also
part of this study and is in agreement with the experimental
results.
The vinylene precursors, 2a−j, set the stage for a final
oxidative−photocyclization process that would eventually give
1
7,18
access to the targeted compounds, 3a−j.
For this
transformation, a medium pressure Hg lamp was used as the
light source, iodine as an oxidant, and propylene oxide as a
quencher for the reaction-produced hydrogen iodide. In
general, the photochemical annulation process required a few
hours for completion. Once again purification of the final
product could be achieved by a simple washing with hexanes.
The overall isolated yields for the 10 prepared compounds
could be calculated to be in the range of 62−92% over the three
synthetic steps. Since these numbers represent unoptimized
processes, it is noteworthy that overall isolated yields can reach
over 90%. Such efficiency of the synthesis coupled with its
practicality is often not associated with the preparation of the
complex polycyclic aromatic hydrocarbon derivatives.
RESULTS AND DISCUSSION
Synthesis. To accomplish the synthesis, initially, an
aldehyde functionality was installed onto corannulene through
the Rieche formylation reaction (Scheme 1). This reaction
■
14
Due to several non-chromatographic purifications and high
reaction yields, the practicality of the whole synthetic process is
such that if multigram quantities of the final products are
required, they can be accessed with ease. To demonstrate this
aspect, compound 3a was synthesized in a 1.3-g scale (Figure
S1). Such scalability is critical if real life applications, such as in
organic electronic devices, are to be targeted using chemistry
based on the corannulene motif.
Scheme 1. Synthesis of Extended and Fluorinated
Corannulenes
In the prepared series (Chart 1), compound 3a serves as a
control in the follow up electrochemical study. Compounds
3b−e are derivatives in which one, two, or three fluorine atoms
are part of the extended segment. Compounds 3c and 3d can
be considered as isomers due to 1,3 (meta) and 1,4 (para)-
arrangement of the fluorine atoms. Compound 3f carries one
trifluoromethyl group, and 3g and 3h carry an additional
fluorine atom at the meta- and para-position related to the CF3
group. Lastly, 3i and 3j are the compounds carrying two
trifluoromethyl groups oriented in the meta- and para-positions
to each other. This diversity of the structures is truly the result
of a modular nature of the employed synthetic scheme, in
which any ylide compound can be combined to the
corannulene scaffold through a Wittig reaction.
Optical Properties. Optical spectroscopy studies revealed
that the extension of the corannulene scaffold with the
naphthalene unit resulted in a bathochromic shift of 12 nm
in the absorption spectrum of 3a (Figure 1). The introduction
of the fluorine atoms resulted into a further shift to the higher
wavelengths by 1−7 nm (3b−i) (Figure S2). The most red-
shifted signal was observed for 3j at 309 nm. This shift
amounted to be about 22 nm when compared to parental
corannulene. This is interesting because the placement of the
trifluoromethyl groups directly onto the corannulene scaffold is
known not to change the optical signature of the core. The
fluorescence emission study showed that a weak signal ranging
from 400 to 500 nm could be observed for all of the
compounds irrespective of the wavelength of excitation (Figure
S3).
proceeds to quantitative conversions and does not require a
chromatographic purification of the formed product. Hence,
multigrams (>10 g) of corannulenecarbaldehyde can be
prepared with synthetic ease.
Next, commercially available and inexpensive benzyl
bromides having a certain fluorination pattern were converted
into phosphonium ylides 1a−j through treatment with
triphenylphosphine. These transformations were also quantita-
tive. Moreover, the formed ylide compounds precipitated out of
the reaction and could be simply collected through a simple
vacuum filtration process.
Electrochemical Properties. Cyclic (CV) and square-
wave voltammetry (SWV) were used to examine the electro-
chemical behavior of 3a−j and to gauge their electron affinities.
B
DOI: 10.1021/acs.joc.7b03146
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The Journal of Organic Chemistry
Article
Chart 1. Molecular Structures of the Final Compounds 3a−j
least 10 further redox cycles (Figure S5). As can be seen in
Figures 2 and S4 and Table 1, pristine corannulene shows a
Figure 2. Overlay of cyclic voltammograms showing the first reduction
process of 1 mM corannulene (black), 3a (red), and 3j (blue) in DMF
−1
containing 0.1 M nBu NPF at a scan rate of 0.1 V s using a 1 mm
4
6
diameter GC working electrode at 298 ± 2 K in a Faraday cage.
Table 1. Measured Reduction Potentials of Corannulene and
a
3a−j As Collected Using Square-Wave Voltammetry
compound
E1/V
E2/V
LUMO/eV
3
j
−1.838
−1.934
−2.039
−2.044
−2.110
−2.110
−2.110
−2.120
−2.150
−2.195
−2.306
−2.195
−2.115
−2.452
−2.488
−2.311
−2.457
−2.331
−2.336
−2.674
−2.744
−2.860
−2.782
−2.722
−2.509
−2.545
−2.411
−2.416
−2.374
−2.325
−2.260
−2.155
−2.020
3
3
3
3
3
3
3
3
3
i
h
g
f
e
c
d
b
a
corannulene
a
First reduction potentials (bold) are arranged in order of increasing
red
Ec/c- . Voltammetric measurements were conducted in a Faraday
cage with a 1 mm diameter planar GC working electrode in DMF
containing 1 mM of compound and 0.1 M nBu NPF at 298 ± 2 K
4
6
−1
and recorded with a scan rate of 0.1 V s . All values are referenced to
the Fc/Fc redox couple. The DFT-computed LUMO energies are
+
listed in the last column for comparison.
1
chemically reversible first reduction process ( E ) at −2.31 V.
PC
The extension of corannulene with naphthalene results in an
increase in the first reduction potential by 0.11 V and indicates
that 3a is a better electron acceptor than corannulene.
Placement of fluorine atoms on the extended scaffold further
enhances the reduction potential (Figure 3). Interestingly,
Figure 1. UV−vis spectra of corannulene (λ = 287 nm, black line),
max max
blue line) in tetrahydrofuran at room temperature.
max
3
a (λ = 270 and 299 nm, red line), and 3j (λ = 278 and 309 nm,
introduction of one CF group, as in the case of 3e, was found
3
The CV experiments indicated that all of the molecules
followed an EEC (E = electron transfer and C = chemical
reaction) mechanism (Figure S4). The first electron transfer
step produced the anion radicals, which could be further
reduced to the dianions at more negative potentials. The
dianions were considerably less long-lived than the anion
radicals as indicated by how the anodic to cathodic peak current
ratio was ≪1. Controlled potential electrolysis experiments also
indicated that the first reduction process resulted in the transfer
of one electron to produce the anion radical that was stable
under the time scale of the experiment (t = 1800 s), and they
could be oxidized back to the neutral species when a sufficiently
positive potential was applied. The reduced species formed at
the end of the electrolysis experiment revealed stability over at
to be as effective as three Ar−F bonds in enhancing the first
reduction potential. Addition of Ar−F to one CF group
3
resulted in a further increase in the reduction potential to −2.04
V for compounds 3g−h (Figure 4). Finally, two CF groups on
3
1
the extended scaffold 3i−j show the highest E in the present
PC
series of compounds of −1.93 and −1.84 V. This means that
the reduction potential enhancement was approximately 0.46 V
when 3j is compared to pristine corannulene (Figure 2).
Although most of the compounds display several reduction
processes, only the first two are likely to be associated with the
reduction of the starting materials, since the second reduction
process was only partially chemically reversible at best (3a−e)
and, in some cases, appeared to involve multiple electron
transfers (3f−j).
C
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The Journal of Organic Chemistry
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Figure 5. (a) DFT-computed LUMO energy plotted against the first
reduction potential measured by CV for corannulene and its
derivatives (3a−j). Visual representation of the computed LUMO
on the molecular skeleton for (b) 3a and (c) 3j.
because the negative values of LUMO energies are linearly
proportional to the first reduction potentials of the corannulene
derivatives. It is also found that LUMO is located more on the
fluorinated (and, therefore, the extended) segment of the
molecule rather than the corannulene bowl. For example, when
3j is compared to 3a, the LUMO is located mostly on the
corannulene nucleus (Figure 5b,c). This suggests that the
increase in the electron affinity in the present series of the
corannulene derivatives can be attributed to the fluorination of
the extended aromatic scaffold.
Figure 3. Cyclic voltammograms showing the first reduction process
of 1 mM 3b−e in DMF containing 0.1 M nBu NPF at a scan rate of
4
6
−
1
0
.1 V s using a 1 mm diameter GC working electrode at 298 ± 2 K
in a Faraday cage.
CONCLUSIONS
■
To summarize, a new family of extended and fluorinated
derivatives of corannulene have been prepared through an
efficient and modular synthetic scheme. This strategy allows for
a large degree of freedom over the choice of the number,
nature, and placement of the fluorine atoms on the extended
aromatic framework. Furthermore, only one synthetic step in
the whole synthesis required a chromatographic purification.
Such practicality can be translated to scalability of the synthesis.
This aspect is demonstrated through the preparation of one of
the family members, 3a, at a 1.3-g scale. The overall
(
unoptimized) yields for the preparation of the 10 family
members (over three synthetic steps) ranged from 62 to 92%.
Optical and electrochemical studies suggest that the electronic
properties of the present material family could be systematically
tuned and enhanced through adjusting the molecular structure.
For instance, a bathochromic shift of 12 nm could be achieved
by attaching a naphthalene unit to the corannulene scaffold
(
3a). Placement of two trifluoromethyl groups on this extended
part of the molecule allows for a further 10 nm red shift (3j).
These structural transformations also make the molecules
better electron acceptors. For example, 3a and 3j show an
increase of reduction potential by 0.11 and 0.46 V, respectively,
in comparison to pristine corannulene. In essence, the
described molecular design concepts can now be applied to
efficiently access a new family of electron acceptor materials
with adjustable electronic properties and anticipated applica-
tions in the arena of organic electronics.
Figure 4. Cyclic voltammograms showing the first reduction process
of 1 mM 3f−j in DMF containing 0.1 M nBu NPF at a scan rate of
4
6
−
1
0
.1 V s using a 1 mm diameter GC working electrode at 298 ± 2 K
in a Faraday cage.
Computational Studies. The density functional theory
(
DFT) results are summarized in Figure 5a with the help of a
plot between the lowest unoccupied molecular orbital
LUMO) energies and the experimentally measured values of
EXPERIMENTAL DETAILS
■
General Methods. All commercial reagents were used without
further purification. Solvents were purified by standard procedures. All
reactions with air- and moisture-sensitive reagents were performed in
vacuum-dried reaction vessels under nitrogen atmosphere. Column
chromatography was carried out on silica gel 40−63 mesh as the
stationary phase. Reactions were monitored by thin-layer chromatog-
(
first reduction potentials. The values of LUMO energies are as
listed in Table 1. As can be seen from these data, the
descending order of LUMO energies is in good agreement with
the ascending order of the first reduction potentials. This is
D
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The Journal of Organic Chemistry
Article
raphy (TLC) on silica gel-coated aluminum plates (60 F254, Merck)
and visualized with UV light (λ = 254 and 366 nm). H and C NMR
residue was purified by column chromatography using mixture of
hexane/EtOAc to give the corannulene vinylenes as a mixture of trans/
cis isomers. The isolated chemical yields ranged from 70 to 93%.
1
13
spectra were recorded with Bruker BBFO-400 and Bruker AV-400
13
1
instruments at room temperature by using CDCl as solvent. For
C
2a. Yield: 92% (1.4 g). Yellow solid. mp 206−208 °C. H NMR
3
NMR measurements in which higher sample concentrations were
needed, CS2 (residual solvent signal = 193 ppm) was added to
enhance the solubility of the compounds. Chemical shifts are recorded
in parts per million (ppm) relative to tetramethylsilane (δ = 0.00 ppm)
and chloroform (δ = 7.26 ppm). 1H NMR splitting patterns are
designated as s (singlet), d (doublet), t (triplet), q (quartet), dd
(400 MHz, CDCl , δ): 8.17 (d, J = 8.8 Hz, 1H), 7.94 (s, 1H), 7.90−
3
7.73 (m, 8H), 7.68 (d, J = 7.5 Hz, 2H), 7.53 (d, J = 16.2 Hz, 1H), 7.45
(t, J = 7.6 Hz, 2H), 7.34 (t, J = 7.3 Hz, 1H). 13C NMR (101 MHz,
CDCl , δ): 137.7, 137.6, 136.4, 136.1, 135.8, 135.6, 135.5, 133.1,
3
131.09, 131.05, 130.9, 129.2, 128.9, 128.1, 127.6, 127.5, 127.4, 127.2,
127.1, 127.09, 127.01, 126.9, 126.7, 125.8, 124.5. HRMS (MALDI-
TOF) (m/z): [M]+ calcd for C H , 352.1247; found, 352.1247.
(
doublet of doublets), m (multiplet), etc. 13C NMR chemical shifts are
28
16
reported relative to CDCl (δ = 77.00 ppm). High-resolution mass
2b. Yield: 73% (120 mg). Light yellow solid. mp 104−106 °C.
3
1
spectra (HRMS) were recorded by using JEOL Spiral TOF (JMS-
S3000) (MALDI) for all starting materials and final compounds.
Photocyclization reactions were carried out in 0.5 and 1 L water-
cooled immersion-well photochemical reactors equipped with a
medium-pressure mercury lamp (125 W).
trans:cis ratio 1:1. H NMR (400 MHz, CDCl , δ): 8.17 (d, J = 8.8 Hz,
3
1H), 7.97 (s, 1H), 7.91−7.62 (m, 18H), 7.42 (t, J = 7.7 Hz, 1H), 7.30
(dd, J = 12.1, 5.7 Hz, 2H), 7.24−6.98 (m, 6H), 6.82 (t, J = 7.5 Hz,
1H). 13C NMR (101 MHz, CDCl
, δ): 161.9, 159.4, 137.4, 136.3,
3
136.2, 135.9, 135.7, 135.6 (d, J = 3.5 Hz), 135.5, 135.45, 135.43, 132.2,
132.1, 131.1 (d, J = 3.3 Hz), 130.9, 130.87, 130.83 (d, J = 2.5 Hz),
130.7 (d, J = 2.4 Hz), 130.6, 129.5, 129.4, 129.2 (d, J = 8.5 Hz), 129.0,
128.8 (d, J = 5.1 Hz), 127.6, 127.4, 127.3 (d, J = 3.0 Hz), 127.2 (d, J =
1.7 Hz), 127.1, 127.0, 126.96, 126.91, 125.9, 125.6, 125.4, 125.3, 125.1
(d, J = 3.5 Hz), 125.0 (d, J = 4.0 Hz), 124.8, 124.3 (d, J = 3.5 Hz),
123.7 (d, J = 3.6 Hz), 116.1, 115.9, 115.7, 115.5. 19F NMR (282 MHz,
Voltammetric Measurements. Voltammetric measurements
were performed using a Metrohm Autolab PGSTAT302N potentiostat
in a three-electrode setup. A 1 mm diameter planar disk glassy carbon
disk (GC, Cypress Systems) was used as a working electrode in
conjunction with a platinum wire counter electrode (Metrohm) and a
silver wire miniature reference electrode (eDAQ) connected to the
test solution via a salt bridge containing 0.5 M tetra-n-butylammonium
hexafluorophosphate (nBu NPF ) in DMF (Tedia). nBu NPF was
CDCl
= 10.8, 7.7, 5.2 Hz). HRMS (MALDI-TOF) (m/z): [M]+ calcd for
15F, 370.1158; found, 370.1162.
2c. Yield: 78% (129 mg). Orange foamy solid. mp 78−80 °C.
, δ): −115.38 to −115.52 (m, J = 8.2, 5.9 Hz), −117.34 (ddd, J
3
4
6
4
6
1
9
synthesized through a standard procedure according to the literature
C H
28
and used as the supporting electrolyte. All voltammetric experiments
were conducted under an argon atmosphere at room temperature in a
Faraday cage. Prior to each scan, the working electrode was cleaned by
polishing it with an alumina oxide (grain size 0.3 μm) slurry on a
Buehler Ultrapad polishing cloth, rinsing it with acetone, and then
drying it with a lint free tissue. In accordance with IUPAC
recommendations, the absolute potentials were calibrated using
ferrocene (Fc) as an internal reference which was added to the test
solution at the end of the measurements.
1
trans:cis ratio 6:5. H NMR (400 MHz, CDCl , δ): 8.14 (d, J = 8.8 Hz,
3
3H), 7.94 (s, 3H), 7.90−7.66 (m, 40H), 7.58 (dd, J = 15.9, 7.1 Hz,
4H), 7.39 (dd, J = 15.4, 8.7 Hz, 1H), 7.20−7.05 (m, 2H), 7.01−6.76
1
3
(m, 10H), 6.73−6.65 (m, 1H), 6.57 (t, J = 7.3 Hz, 1H). C NMR
(101 MHz, CDCl , δ): 163.7, 163.6, 161.9, 161.8, 161.2, 161.1, 159.4,
3
159.3, 137.3, 136.3, 135.9, 135.7, 135.5, 131.0, 130.83, 130.80, 130.7,
129.4, 128.5 (dd, J = 5.1, 2.4 Hz), 128.1 (dd, J = 9.5, 5.2 Hz), 127.6,
127.4, 127.3, 127.15, 127.07, 127.03, 126.9, 125.8, 125.5, 124.7,
124.18−124.09 (m), 123.9, 123.8, 121.8 (dd,, J = 12.2, 3.9 Hz), 111.9
(d, J = 3.7 Hz), 111.6 (d, J = 3.7 Hz), 111.1 (dt, J = 21.4, 4.8 Hz),
Controlled-Potential Electrolysis. Controlled potential electrol-
ysis experiments were conducted in a two-compartment electrolysis
cell separated by a sintered glass frit with a porosity number 5 (1.0−
104.6, 104.3, 104.1. 19F NMR (282 MHz, CDCl
, δ): −110.38 (dd, J =
3
1
.7 μm). Two symmetrically arranged and identically sized hollow,
15.4, 7.8 Hz), −110.53 (dt, J = 15.5, 7.8 Hz), −110.70 (dd, J = 17.7,
8.5 Hz), −111.51 (d, J = 9.1 Hz), −113.45 (dd, J = 18.4, 8.2 Hz),
−113.98 (d, J = 10.4 Hz). HRMS (MALDI-TOF) (m/z): [M]+ calcd
cylindrical GC rods (working and auxiliary electrodes) were used. The
silver wire miniature reference electrode (eDAQ) was connected to
the test solution via a salt bridge containing 0.5 M nBu NPF in DMF.
for C28H F , 388.1064; found, 388.1082.
4
6
14 2
The volume of the solutions in both the counter and working
electrode compartments were 25 mL, and stirring was induced via
forced convection through bubbling with argon and N2 at room
temperature (298 ± 2 K). The total number of electrons transferred
during CPE was calculated from the following equation: n = Q/NF,
where N = the number of moles of the starting material used, Q = the
charge (in coulombs), n = the number of electrons, and F is the
Faraday constant (96485 C/mol).
General Procedure for the Synthesis of Triphenylphospho-
nium Salts 1a−j. Triphenylphosphine (1.2 equiv) was added to a
stirred solution of a commercially available derivatives of benzyl
bromide (300 mg, 1.0 equiv) in 20 mL toluene, and the reaction
mixture was refluxed for 12 h. After completion of reaction, the
reaction mixture was cooled to room temperature and the resulting
phosphonium salt precipitate was collected by filtration and dried. In
all cases, the isolated chemical yields were quantitative.
2d. Yield: 77% (128 mg). Orange foamy solid. mp 80−82 °C.
1
trans:cis ratio 6:5. H NMR (400 MHz, CDCl , δ): 8.15 (d, J = 8.8 Hz,
3
4H), 7.96 (d, J = 6.4 Hz, 4H), 7.91−7.73 (m, 47H), 7.69 (dd, J = 5.9,
2.7 Hz, 6H), 7.62 (d, J = 16.4 Hz, 4H), 7.44 (ddd, J = 9.0, 5.7, 3.0 Hz,
1
3
4H), 7.21−6.90 (m, 18H), 6.89−6.80 (m, 3H), 6.72 (s, 1H).
C
NMR (101 MHz, CDCl , δ): 160.8 (d, J = 2.3 Hz), 157.8 (d, J = 2.4
3
Hz), 155.3 (d, J = 2.3 Hz), 136.8, 136.3, 135.9, 135.7, 135.6, 135.4,
130.97, 130.90, 130.7, 130.6, 129.9 (d, J = 4.6 Hz), 128.8, 127.7, 127.5,
127.4, 127.0, 126.9, 125.6, 125.4, 125.2, 124.8, 123.93−123.83 (m),
116.9 (dd, J = 25.2, 8.8 Hz), 116.1, 115.9, 115.5 (dd, J = 24.6, 8.6 Hz),
113.1 (d, J = 3.8 Hz), 112.8 (d, J = 3.8 Hz). 19F NMR (282 MHz,
CDCl , δ): −117.97 to −118.25 (m), −118.21 to −118.52 (m),
3
−118.84 to −119.35 (m), −120.83 to −121.00 (m), −121.31 to
−121.62 (m), −123.63 to −123.94 (m). HRMS (MALDI-TOF) (m/
z): [M]+ calcd for C28H F , 388.1064; found, 388.1069.
14 2
2e. Yield: 83% (139 mg). Beige solid. mp 159−160 °C. trans:cis
1
General Procedure for the Synthesis of Stilbene-like
Vinylene Derivatives 2a−j through the Wittig Reaction. As a
typical procedure, n-BuLi (2.0 M solution in hexane) was added to a
vacuum-dried round-bottom flask containing a suspension of
benzyltriphenylphosphonium bromide (0.66 mmol) in 35 mL of dry
ratio 2:1. H NMR (400 MHz, CDCl , δ): 8.10 (d, J = 8.8 Hz, 9H),
3
7.91 (s, 9H), 7.90−7.74 (m, 90H), 7.73−7.59 (m, 25H), 7.32 (dd, J =
16.2, 10.5 Hz, 10H), 7.26−7.21 (m, 17H), 7.12−7.04 (m, 12H), 6.85−
6.71 (m, 7H), 6.51 (s, 1H). 13C NMR (101 MHz, CDCl , δ): 152.9 (d,
3
J = 4.2 Hz), 152.8 (d, J = 4.4 Hz), 150.4 (d, J = 4.4 Hz), 150.3 (d, J =
4.5 Hz), 138.0, 137.9, 136.4, 136.2, 136.0, 135.9, 135.7 (d, J = 6.6 Hz),
135.5, 135.0, 133.8 (dt, J = 10.3, 5.2 Hz), 133.1, 131.0, 130.9, 130.8,
130.7 (d, J = 1.8 Hz), 130.6, 130.0 (d, J = 1.3 Hz), 129.6 (d, J = 2.6
Hz), 129.5, 129.0 (d, J = 2.6 Hz), 128.7, 127.8, 127.6, 127.5, 127.4,
127.3, 127.2, 127.1, 127.05, 127.00, 126.96, 126.88, 125.5, 125.3 (d, J =
THF (0.330 mL) at 0 °C under a N atmosphere. The mixture was
2
stirred for 30 min. Corannulenecarbaldehyde (0.44 mmol) in 5 mL of
dry THF was added, and the solution was stirred at room temperature
for 2−3 h. The progress of the reaction was monitored by TLC. After
completion of the reaction, the reaction mixture was quenched with
water and then extracted with CH Cl (3 × 100 mL). The combined
1
9
3.0 Hz), 113.4 (dd, J = 16, 5.8 Hz), 110.3 (dd, J = 15.8, 6.0 Hz).
F
2
2
organic layers were dried (anhydrous Na SO ) and concentrated. The
NMR (282 MHz, CDCl , δ): −132.98 (dd, J = 20.5, 8.0 Hz), −133.46
2
4
3
E
DOI: 10.1021/acs.joc.7b03146
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
(
−
ddd, J = 31.7, 20.4, 8.4 Hz), −133.74 to −134.00 (m), −134.15 to
(d, J = 4.0 Hz), 135.4, 134.6, 132.6, 131.8, 131.1, 131.0 (d, J = 1.4 Hz),
130.9, 130.8, 130.6, 130.5 (d, J = 3.1 Hz), 129.3 (dd, J = 7.3, 3.6 Hz),
129.0, 128.7, 127.9 (d, J = 3.2 Hz), 127.6, 127.5, 127.4, 127.34, 127.32,
127.28, 127.21, 127.09, 127.03, 126.9, 126.8 (d, J = 1.7 Hz), 126.7,
134.36 (m), −159.44 to −159.70 (m), −159.96 to −160.20 (m),
160.38 to −160.71 (m), −160.85 (tt, J = 20.7, 6.5 Hz). HRMS
−
(
MALDI-TOF) (m/z): [M]+ calcd for C H F , 406.0963; found,
28 13 3
19
4
06.0944.
f. Yield: 93% (160 mg). Yellow solid. mp 140−141 °C. trans:cis
126.3, 125.3, 125.2, 124.3, 124.12−123.81 (m), 122.4. F NMR (282
2
MHz, CDCl , δ): −60.00 (s), −61.05 (s), −63.28 (s), −63.87 (s).
3
1
ratio 1:1. H NMR (400 MHz, CDCl , δ): 8.16 (d, J = 8.8 Hz, 1H),
7
Hz, 2H), 7.79 (ddd, J = 17.0, 8.3, 6.2 Hz, 14H), 7.71−7.58 (m, 4H),
HRMS (MALDI-TOF) (m/z): [M]+ calcd for C H F , 488.0994;
3
30 14 6
.96 (d, J = 5.4 Hz, 2H), 7.92 (d, J = 2.2 Hz, 1H), 7.87 (dd, J = 9.2, 6.4
found, 488.0974.
General Procedure for Oxidative Photocyclizations. As a
typical procedure, a solution containing corannulene vinylene (0.135
7
7
.57 (s, 1H), 7.44 (dd, J = 15.2, 7.6 Hz, 2H), 7.23 (t, J = 6.2 Hz, 2H),
.16 (t, J = 7.6 Hz, 1H). 13C NMR (101 MHz, CDCl , δ): 137.0, 136.5
3
mmol), I (37.7 mg, 0.148 mmol), and propylene-oxide (0.95 mL, 100
2
(
d, J = 1.5 Hz), 136.3, 136.2, 136.1 (d, J = 1.8 Hz), 136.0, 135.8, 135.7,
35.65, 135.62, 135.57, 135.51, 135.47, 135.41, 132.1, 132.0 (d, J = 0.6
Hz), 131.4 (d, J = 0.4 Hz), 130.99, 130.92, 130.89, 130.87, 130.78,
equiv 100.0 equiv) in 125 mL of toluene was irradiated in a
photoreactor fitted with a water-cooled immersion flask and a
1
medium-pressure Hg lamp (125 W) under a N atmosphere. The
2
1
1
1
6
30.71, 130.67, 130.65, 130.63, 129.9, 129.5, 129.1 (d, J = 0.9 Hz),
28.9, 128.7, 128.4 (d, J = 2.0 Hz), 127.9, 127.75, 127.73, 127.6, 127.5,
27.4, 127.3, 127.1 (ddd, J = 16.8, 11.8, 2.6 Hz), 126.1 (dd, J = 11.9,
.1 Hz), 125.97, 125.95, 125.93, 125.6, 125.5 (d, J = 1.3 Hz), 123.2 (d,
progress of the reaction was monitored by disappearance of the iodine
color as well as by TLC (Hex/EtOAc 7/3). After the reaction
completion (3−4 h), the reaction mixture was quenched with
saturated Na S O and extracted. The aqueous solution was extracted
2
2
3
19
J = 4.1 Hz). F NMR (282 MHz, CDCl , δ): −59.30 (s), −60.49 (s).
HRMS (MALDI-TOF) (m/z): [M]+ calcd for C H F , 420.1126;
found, 420.1121.
g. Yield: 89% (150 mg). Yellow solid. mp 134−136 °C. trans:cis
ratio 20:3. H NMR (400 MHz, CDCl , δ): 8.14 (d, J = 8.8 Hz, 4H),
7
4
1
1
1
1
1
1
3
again with CH Cl (4 × 20 mL). The combined organic layers were
2 2
29
15
3
dried (anhydrous Na SO ) and concentrated. The products were
2 4
purified by washing with hexane several times.
2
1
3
a. Yield: 98% (1.36 g). Beige solid. mp 256−257 °C. H NMR
1
3
(400 MHz, CDCl , δ): 9.50 (d, J = 8.5 Hz, 1H), 8.67 (dd, J = 8.8, 2.0
3
.95 (s, 4H), 7.92−7.56 (m, 50H), 7.21−7.14 (m, 1H), 7.14−7.06 (m,
Hz, 2H), 8.35 (d, J = 8.7 Hz, 1H), 8.08 (dd, J = 8.5, 3.8 Hz, 2H), 7.96
13
H), 7.01−6.91 (m, 1H). C NMR (101 MHz, CDCl , δ): 165.9,
13
3
(d, J = 8.7 Hz, 1H), 7.92−7.78 (m, 6H), 7.69 (t, J = 7.5 Hz, 1H).
C
65.1, 163.5, 162.6, 139.4 (dd, J = 8.5, 1.3 Hz), 139.1 (d, J = 9.0 Hz),
36.4, 136.3, 136.2, 135.9, 135.8, 135.76, 135.69, 135.63−135.55 (m),
35.4, 134.9, 131.9, 131.1, 131.0 (d, J = 1.1 Hz), 130.93, 130.86,
30.79, 130.65, 130.56, 129.2, 128.74, 128.69−128.37 (m), 127.9,
27.8, 127.5, 127.4, 127.34, 127.25, 127.19, 127.11, 127.04, 126.94,
26.9, 126.0, 125.6, 125.3, 124.1, 123.8, 122.9, 119.2, 118.9, 114.5 (d, J
NMR (101 MHz, CDCl , δ): 137.9, 135.6, 135.4, 135.3, 134.9, 133.4,
3
1
1
1
3
31.9, 131.3, 131.2, 131.1, 130.8, 130.7, 129.1, 128.9, 128.85, 128.81,
28.6, 127.97, 127.94, 127.8, 127.4, 127.3, 127.1, 126.9, 126.8, 126.4,
24.6, 122.8. HRMS (MALDI-TOF) (m/z): [M]+ calcd for C H ,
2
8
14
50.1090; found, 350.1095.
1
3b. Yield: 85% (42 mg). Light yellow solid. mp 226−228 °C. H
=
2.6 Hz), 114.2 (d, J = 2.5 Hz), 113.9, 113.7. 19F NMR (282 MHz,
NMR (400 MHz, CDCl , δ): 9.28 (d, J = 8.6 Hz, 1H), 8.75 (d, J = 8.9
3
CDCl , δ): −58.62 (s), −59.78 (s). HRMS (MALDI-TOF) (m/z):
3
Hz, 1H), 8.65 (d, J = 8.8 Hz, 1H), 8.40 (dd, J = 8.8, 4.7 Hz, 2H), 8.01
[
M]+ calcd for C H F , 438.1032; found, 438.1033.
29 14 4
(
1
d, J = 8.7 Hz, 1H), 7.96−7.88 (m, 2H), 7.84 (m, 3H), 7.75 (dd, J =
2
h. Yield: 85% (143 mg). Yellow solid. mp 143−145 °C. trans:cis
13
4.5, 7.5 Hz, 1H), 7.38 (t, J = 8.9 Hz, 1H). C NMR (101 MHz,
1
ratio 1:1. H NMR (400 MHz, CDCl , δ): 8.13 (d, J = 8.8 Hz, 1H),
3
CDCl , δ): 160.6, 158.1, 137.9, 135.6, 135.5 (d, J = 2.0 Hz), 134.8,
3
7
1
1
8
1
1
.96−7.90 (m, 2H), 7.88−7.72 (m, 13H), 7.71−7.61 (m, 4H), 7.56 (s,
H), 7.45 (ddd, J = 14.4, 8.8, 5.6 Hz, 3H), 7.33 (td, J = 8.3, 2.6 Hz,
H), 7.23 (d, J = 12.2 Hz, 1H), 7.13 (d, J = 14.1 Hz, 1H), 6.86 (td, J =
1
1
33.4 (d, J = 4.0 Hz), 131.7, 131.1, 130.9, 130.7 (d, J = 2.7 Hz), 128.8,
28.7, 128.5, 128.1, 128.0, 127.5, 127.4, 127.2, 126.9, 126.7, 126.6,
.4, 2.7 Hz, 1H). 13C NMR (101 MHz, CDCl , δ): 162.8, 162.4, 160.3,
124.5, 124.3 (d, J = 4.0 Hz), 123.4, 123.2 (d, J = 1.8 Hz), 119.8 (d, J =
3
19
6
=
.9 Hz), 110.3, 110.1. F NMR (282 MHz, CDCl , δ): −121.48 (dd, J
3
59.9, 136.8, 136.3, 136.2, 135.9, 135.8, 135.73−135.60 (m), 135.5,
35.4, 135.3, 134.2 (d, J = 7.8 Hz), 132.7, 132.1, 130.98 (d, J = 2.0
10.0, 5.9 Hz). HRMS (MALDI-TOF) (m/z): [M]+ calcd for
C H F, 368.1001; found, 368.1021.
28
13
Hz), 130.93, 130.86, 130.77, 130.67, 130.65, 130.61, 130.3, 129.3,
1
1
1
3c. Yield: 91% (45 mg). Beige solid. mp 266−268 °C. H NMR
29.2 (d, J = 7.8 Hz), 128.8, 127.9, 127.8, 127.7, 127.5, 127.39, 127.38,
27.33, 127.25, 127.17, 127.11, 127.0, 126.92, 126.90, 125.5 (d, J = 4.3
(
400 MHz, CDCl , δ): 8.96 (d, J = 11.3 Hz, 1H), 8.71 (d, J = 8.9 Hz,
3
19
1H), 8.60 (d, J = 8.8 Hz, 1H), 8.36 (t, J = 9.4 Hz, 2H), 8.01 (d, J = 8.7
Hz), 125.4, 119.2, 119.0, 118.6, 118.4, 113.97−113.47 (m). F NMR
13
Hz, 1H), 7.96−7.80 (m, 5H), 7.21 (t, J = 8.3 Hz, 1H). C NMR (101
(
282 MHz, CDCl , δ): −59.86 (s), −61.01 (s). HRMS (MALDI-
3
MHz, CDCl , δ): 162.1 (d, J = 13.1 Hz), 161.0 (d, J = 13.7 Hz), 159.7
3
TOF) (m/z): [M]+ calcd for C H F , 438.1032; found, 438.1024.
29
14 4
(d, J = 13.2 Hz), 158.5 (d, J = 13.6 Hz), 137.9, 135.6, 135.5, 135.4,
2
i. Yield: 89% (152 mg). Yellow solid. mp 165−167 °C. trans:cis
1
134.7, 133.3 (dd, J = 11.5, 6.6 Hz), 132.6, 131.1, 130.9 (d, J = 1.6 Hz),
ratio 1:1. H NMR (400 MHz, CDCl , δ): 8.14 (d, J = 8.9 Hz, 1H),
3
1
1
1
30.08−139.96 (m), 128.5, 128.3, 128.2, 128.0, 127.9, 127.6, 127.4,
26.9, 124.4, 122.5 (t, J = 2.1 Hz), 120.4 (d, J = 1.7 Hz), 120.2 (d, J =
.5 Hz), 119.8 (dd, J = 6.5, 1.7 Hz), 108.7 (d, J = 4.3 Hz), 108.4 (d, J =
8
7
7
0
.08 (d, J = 8.3 Hz, 1H), 7.99 (d, J = 9.1 Hz, 3H), 7.93−7.86 (m, 3H),
.86−7.74 (m, 12H), 7.74−7.62 (m, 3H), 7.58 (d, J = 8.1 Hz, 1H),
.55 (d, J = 1.0 Hz, 1H), 7.41 (d, J = 8.1 Hz, 1H), 7.35 (dd, J = 12.1,
19
.9 Hz, 1H), 7.18 (d, J = 11.5 Hz, 1H). 13C NMR (101 MHz, CDCl3,
4.4 Hz), 101.9, 101.6 (d, J = 4.7 Hz), 101.4.
F NMR (373 MHz,
CDCl , δ): −110.69 (dt, J = 11.3, 8.1 Hz), −116.70 to −116.81 (m).
δ): 140.1, 140.0, 136.4, 136.2 (d, J = 2.4 Hz), 136.0, 135.9, 135.8,
3
HRMS (MALDI-TOF) (m/z): [M]+ calcd for C H F , 386.0907;
1
1
1
3
1
1
35.7 (d, J = 3.4 Hz), 135.6 (d, J = 3.5 Hz), 135.4, 134.8, 133.1, 132.8,
31.9, 131.1 (d, J = 2.3 Hz), 131.0, 130.9, 130.8 (d, J = 3.5 Hz), 130.7,
30.5 (d, J = 3.0 Hz), 129.8, 129.4, 129.29, 129.24, 129.1, 128.8 (d, J =
.2 Hz), 128.7, 128.4, 128.1, 127.9, 127.7, 127.6, 127.5, 127.4, 127.3,
28 12 2
found, 386.0925.
1
3d. Yield: 81% (41 mg). Dark yellow solid. mp 238−240 °C. H
NMR (400 MHz, CDCl , δ): 8.76 (d, J = 9.0 Hz, 1H), 8.41 (t, J = 7.2
3
Hz, 1H), 8.35 (d, J = 8.8 Hz, 1H), 8.18 (dd, J = 10.7, 8.9 Hz, 1H), 8.02
(d, J = 8.8 Hz, 1H), 7.90−7.76 (m, J = 15.2, 13.5, 8.9 Hz, 5H), 7.53−
27.2, 127.1, 127.0, 126.95, 126.94, 126.8, 126.7, 126.3, 125.2, 125.1,
23.4, 122.4. 19F NMR (282 MHz, CDCl , δ): −59.88 (s), −61.00 (s),
3
7
.40 (m, J = 14.5, 12.3, 10.2 Hz, 1H), 7.34 (td, J = 8.8, 3.6 Hz, 1H).
−
62.92 (d, J = 37.3 Hz). HRMS (MALDI-TOF) (m/z): [M]+ calcd
1
3
C NMR (101 MHz, CDCl , δ): 156.7, 156.3, 154.2, 153.9, 139.1,
for C H F , 488.1000; found, 488.0999.
3
30
14 6
2
j. Yield: 70% (120 mg). Yellow solid. mp 133−134 °C. trans:cis
137.9, 136.2, 135.2 (d, J = 8.6 Hz), 134.8, 132.7, 131.0 (d, J = 3.8 Hz),
130.9, 129.9 (d, J = 2.4 Hz), 129.6, 129.4, 128.0, 127.4 (d, J = 3.7 Hz),
127.1, 126.9, 126.5 (d, J = 3.7 Hz), 124.6, 124.1, 119.9 (dd, J = 6.7, 2.0
Hz), 111.9 (d, J = 9.0 Hz), 111.6 (d, J = 8.9 Hz), 110.5 (d, J = 9.2 Hz),
1
ratio 3:4. H NMR (400 MHz, CDCl , δ): 8.18 (s, 1H), 8.15 (d, J =
3
8
.9 Hz, 1H), 7.98 (s, 1H), 7.91 (s, 1H), 7.90−7.76 (m, 18H), 7.74 (dd,
J = 7.0, 5.6 Hz, 2H), 7.71−7.63 (m, 3H), 7.59 (dd, J = 4.9, 4.0 Hz,
H), 7.52 (d, J = 8.2 Hz, 1H), 7.31 (dt, J = 7.2, 3.6 Hz, 1H), 7.18 (dd,
J = 12.1, 2.3 Hz, 1H). C NMR (101 MHz, CDCl , δ): 137.6, 137.3,
36.39, 136.33, 136.2, 136.0, 135.9, 135.2, 135.7 (d, J = 1.9 Hz), 135.6
110.3 (d, J = 9.2 Hz). 19F NMR (373 MHz, CDCl , δ): −108.40 to
2
3
13
−108.56 (m), −125.92 to −126.05 (m). HRMS (MALDI-TOF) (m/
z): [M]+ calcd for C H F , 386.0907; found, 386.0919.
3
1
28
12 2
F
DOI: 10.1021/acs.joc.7b03146
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
1
3
e. Yield: 75% (37 mg). Beige solid. mp 298−299 °C. H NMR
Computational Methods. Geometry optimizations were per-
formed for corannulene and its derivatives (3a−j) using DFT as
(
400 MHz, CDCl , δ): 8.68 (d, J = 8.8 Hz, 1H), 8.36 (d, J = 8.8 Hz,
3
1
7
1
H), 8.17−8.09 (m, 1H), 7.99 (t, J = 8.7 Hz, 2H), 7.89−7.79 (m, 5H),
implemented in the Amsterdam density functional (ADF) pro-
.63 (dd, J = 16.7, 8.8 Hz, 1H). 13C NMR (101 MHz, CDCl , δ):
20,21
gram
with the B3LYP functional and the all-electron triple-ζ
3
22,23
37.9, 136.2, 135.4, 135.2, 134.9, 131.1 (d, J = 1.4 Hz), 130.9, 129.5
double polarization (TZ2P) basis set.
In the process of
(
1
d, J = 2.3 Hz), 129.1, 128.9, 128.1, 127.5 (d, J = 1.0 Hz), 127.4, 127.1,
27.0, 126.8, 126.74, 126.70, 126.68, 126.66, 124.4, 124.2 (d, J = 2.2
optimization, vibrational frequency calculations confirmed no
imaginary frequencies for each of the optimized molecules, which
indicates that the optimized structures are at the minima of the
potential energy surface.
19
Hz), 109.4 (d, J = 4.0 Hz), 109.3 (d, J = 4.1 Hz). F NMR (373 MHz,
CDCl , δ): −126.82 to −127.02 (m), −134.07 to −134.33 (m),
3
−
158.83 (ddd, J = 20.7, 18.2, 7.4 Hz). HRMS (MALDI-TOF) (m/z):
[
M]+ calcd for C H F , 404.0813; found, 404.0817.
ASSOCIATED CONTENT
Supporting Information
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.joc.7b03146.
2
8
11 3
■
1
3
f. Yield: 99% (49 mg). Beige solid. mp 205−207 °C. H NMR
*
S
(
1
1
400 MHz, CDCl , δ): 9.65 (d, J = 8.6 Hz, 1H), 8.79 (d, J = 9.2 Hz,
3
H), 8.53−8.43 (m, 2H), 8.35 (d, J = 8.8 Hz, 1H), 8.08 (d, J = 7.3 Hz,
13
H), 7.98 (d, J = 8.7 Hz, 1H), 7.92−7.76 (m, 6H). C NMR (101
MHz, CDCl , δ): 137.8, 135.8, 135.4, 134.7, 133.0, 132.4, 131.4, 131.0
NMR spectra of products (PDF)
3
(
3
d, J = 1.3 Hz), 130.8, 130.7, 129.0, 128.6, 128.4, 128.1, 128.0 (d, J =
.0 Hz), 127.6, 127.3, 127.2, 127.0, 126.8, 126.6, 126.3, 124.9, 124.8
Large scale syntheses procedures, optical and CV
characterization, and DFT-calculations details (PDF)
19
(
dd, J = 11.9, 6.0 Hz), 124.4, 124.3, 123.6, 123.2 (q, J = 2.6 Hz). F
NMR (282 MHz, CDCl , δ): −59.16 (s). HRMS (MALDI-TOF) (m/
3
AUTHOR INFORMATION
Corresponding Authors
*E-mail: junehuh@korea.ac.kr
E-mail: mstuparu@ntu.edu.sg
z): [M]+ calcd for C H F , 418.0963; found, 418.0943.
■
2
9
13 3
1
3
g. Yield: 100% (50 mg). Beige solid. mp 223−225 °C. H NMR
(
400 MHz, CDCl , δ): 8.82 (d, J = 9.2 Hz, 1H), 8.44−8.37 (m, 2H),
3
8
1
1
1
1
.14−8.00 (m, 3H), 7.90−7.77 (m, 5H), 7.54 (dd, J = 11.8, 8.2 Hz,
*
H). 13C NMR (101 MHz, CDCl , δ): 162.9, 160.4, 137.7, 136.1,
3
ORCID
35.1, 135.0, 134.6, 132.1, 131.6 (d, J = 4.6 Hz), 131.0, 130.9, 130.8,
29.8 (d, J = 3.1 Hz), 129.2, 129.0, 128.0, 127.4, 127.1, 127.1, 127.0,
26.99, 126.91, 126.8, 126.6 (d, J = 3.5 Hz), 125.9 (dd, J = 10.6, 6.0
Mihaiela C. Stuparu: 0000-0001-8663-6189
Notes
The authors declare no competing financial interest.
Hz), 125.4, 124.4, 123.3, 123.11−122.98 (m), 122.9 (d, J = 3.9 Hz),
1
22.6 (d, J = 3.8 Hz), 121.7, 121.6, 120.5, 110.9, 110.6. 19F NMR (282
MHz, CDCl , δ): −58.57 (s), −97.16 (t, J = 9.9 Hz). HRMS (MALDI-
3
ACKNOWLEDGMENTS
■
TOF) (m/z): [M]+ calcd for C H F , 436.0869; found, 436.0848.
2
9
12 4
1
M.C.S. wishes to thank NTU Singapore (M4081566) for
financial support. J.H. acknowledges support from NRF-Korea
(NRF-2016R1A6A3A11933393).
3
h. Yield: 99% (49 mg). Beige solid. mp 221−222 °C. H NMR
400 MHz, CDCl , δ): 9.37 (dd, J = 10.7, 2.3 Hz, 1H), 8.78 (d, J = 9.2
(
3
Hz, 1H), 8.52 (d, J = 8.8 Hz, 1H), 8.43 (dd, J = 9.2, 1.6 Hz, 1H), 8.37
(
7
d, J = 8.8 Hz, 1H), 8.02 (d, J = 8.7 Hz, 1H), 7.95 (d, J = 8.8 Hz, 1H),
.93−7.82 (m, 4H), 7.80 (d, J = 5.6 Hz, 1H). C NMR (101 MHz,
13
REFERENCES
■
CDCl , δ): 160.9, 158.4, 137.9, 135.8, 135.7, 135.4 (d, J = 5.4 Hz),
3
(1) Kuvychko, I. V.; Spisak, S. N.; Chen, Y.-S.; Popov, A. A.;
Petrukhina, M. A.; Strauss, S. H.; Boltalina, O. V. Angew. Chem., Int. Ed.
1
1
1
1
34.6, 133.8 (d, J = 8.4 Hz), 131.8, 131.1, 131.0, 130.9 (d, J = 4.5 Hz),
30.7 (d, J = 4.9 Hz), 128.5, 128.2, 127.9 (d, J = 3.5 Hz), 127.7, 127.4,
27.0, 126.9, 126.0, 125.3, 124.3, 123.8 (d, J = 2.2 Hz), 123.1, 116.9,
16.8, 115.3 (d, J = 6.1 Hz), 115.0 (d, J = 6.2 Hz). 19F NMR (282
2
(
012, 51 (20), 4939−4942.
2) Schmidt, B. M.; Seki, S.; Topolinski, B.; Ohkubo, K.; Fukuzumi,
S.; Sakurai, H.; Lentz, D. Angew. Chem., Int. Ed. 2012, 51 (45), 11385−
11388.
(3) Kuvychko, I. V.; Dubceac, C.; Deng, S. H. M.; Wang, X.-B.;
Granovsky, A. A.; Popov, A. A.; Petrukhina, M. A.; Strauss, S. H.;
Boltalina, O. V. Angew. Chem., Int. Ed. 2013, 52 (29), 7505−7508.
(4) Schmidt, B. M.; Topolinski, B.; Yamada, M.; Higashibayashi, S.;
Shionoya, M.; Sakurai, H.; Lentz, D. Chem. - Eur. J. 2013, 19 (41),
MHz, CDCl , δ): −59.39 (s), −113.24 − −113.43 (m). HRMS
3
(
MALDI-TOF) (m/z): [M]+ calcd for C H F , 436.0875; found,
29 12 4
4
36.0896.
1
3
i. Yield: 99% (49 mg). Beige solid. mp 223−224 °C. H NMR
(
(
400 MHz, CDCl , δ): 10.02 (s, 1H), 8.93 (d, J = 9.2 Hz, 1H), 8.50
dd, J = 9.1, 1.6 Hz, 1H), 8.45 (d, J = 8.8 Hz, 1H), 8.37 (d, J = 8.8 Hz,
3
1
H), 8.27 (s, 1H), 8.00 (dd, J = 18.2, 8.7 Hz, 2H), 7.93−7.79 (m, 4H).
1
3872−13880.
1
3
C NMR (101 MHz, CDCl , δ): 137.9, 135.8, 135.7 (d, J = 4.1 Hz),
3
(5) Xia, Y.; Guo, T.; Baldridge, K. K.; Siegel, J. S. Eur. J. Org. Chem.
1
2
1
1
35.4, 134.6, 131.9, 131.8 (d, J = 1.8 Hz), 131.2, 131.1, 130.9 (d, J =
.5 Hz), 130.5 (dd, J = 9.1, 4.6 Hz), 130.4, 128.9, 128.6, 128.48−
28.41 (m), 128.3, 128.3, 127.99, 127.92, 127.8, 127.7, 127.6, 127.5,
27.4, 127.3, 127.0 (d, J = 3.3 Hz), 126.9, 126.8, 125.9, 124.2, 122.9
2017, 2017 (4), 875−879.
(6) Schmidt, B. M.; Lentz, D. Chem. Lett. 2014, 43 (2), 171−177.
(7) Dutta, A. K.; Linden, A.; Zoppi, L.; Baldridge, K. K.; Siegel, J. S.
Angew. Chem., Int. Ed. 2015, 54 (37), 10792−10796.
(8) Rajeshkumar, V.; Stuparu, M. C. Chem. Commun. 2016, 52,
9957−9960.
(
d, J = 2.8 Hz), 120.70, 120.68, 120.65. 19F NMR (282 MHz, CDCl3,
δ): −59.62 (s), −62.21 (s). HRMS (MALDI-TOF) (m/z): [M]+
calcd for C H F , 486.0837; found, 486.0823.
3
0
12 6
(9) Sygula, A.; Sygula, R.; Rabideau, P. W. Org. Lett. 2006, 8 (25),
5909−5911.
1
3
j. Yield: 99% (49 mg). Light yellow solid. mp 207−208 °C. H
NMR (400 MHz, CDCl , δ): 8.76 (d, J = 9.1 Hz, 1H), 8.43−8.33 (m,
2
Hz, 2H), 7.88−7.73 (m, 4H), 7.47−7.32 (m, 1H). C NMR (101
MHz, CDCl , δ): 137.9, 137.2, 135.8, 135.6, 135.3, 133.4, 133.3, 133.0,
́
(10) Rajeshkumar, V.; Courte, M.; Fichou, D.; Stuparu, M. C. Eur. J.
3
H), 8.24 (d, J = 7.8 Hz, 1H), 8.17 (d, J = 7.8 Hz, 1H), 8.00 (d, J = 8.8
Org. Chem. 2016, 2016 (36), 6010−6014.
13
(11) Boedigheimer, H.; Ferrence, G. M.; Lash, T. D. J. Org. Chem.
2010, 75 (8), 2518−2527.
3
1
1
1
32.3, 131.79, 131.76, 131.74, 131.72, 131.3, 131.1, 130.8, 130.6,
29.9, 129.6, 129.4, 128.9, 128.6, 128.3, 127.9, 127.5 (d, J = 3.4 Hz),
27.3, 127.2 (d, J = 3.4 Hz), 127.0 (d, J = 2.4 Hz), 126.9 (d, J = 4.8
(12) Ota, K.; Tanaka, T.; Osuka, A. Org. Lett. 2014, 16 (11), 2974−
2977.
(13) Li, J.; Terec, A.; Wang, Y.; Joshi, H.; Lu, Y.; Sun, H.; Stuparu, M.
C. J. Am. Chem. Soc. 2017, 139 (8), 3089−3094.
(14) Rajeshkumar, V.; Lee, Y. T.; Stuparu, M. C. Eur. J. Org. Chem.
2016, 2016 (1), 36−40.
Hz), 125.9, 125.5, 125.3, 125.0, 123.8 (q, J = 6.1 Hz), 123.2, 122.7 (dd,
J = 5.2, 2.4 Hz). 19F NMR (282 MHz, CDCl , δ): −50.11 (s), −59.17
3
(
s). HRMS (MALDI-TOF) (m/z): [M]+ calcd for C H F ,
30 12 6
4
86.0843; found, 486.0836.
(15) Wittig, G.; Scho
̈
llkopf, U. Chem. Ber. 1954, 87 (9), 1318−1330.
G
DOI: 10.1021/acs.joc.7b03146
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
(
(
16) Wittig, G.; Haag, W. Chem. Ber. 1955, 88 (11), 1654−1666.
17) Scholz, M.; Muhlstadt, M.; Dietz, F. Tetrahedron Lett. 1967, 8
̈
̈
(
7), 665−668.
18) Flammang-Barbieux, M.; Nasielski, J.; Martin, R. H. Tetrahedron
Lett. 1967, 8, 743−744.
19) Kissinger, P.; Heineman, W. R. Laboratory Techniques in
Electroanalytical Chemistry, Second ed.; CRC Press, 1996.
20) te Velde, G.; Bickelhaupt, F. M.; Baerends, E. J.; Guerra, C. F.;
Van Gisbergen, S.; Snijders, J. G.; Ziegler, T. J. Comput. Chem. 2001,
2 (9), 931−967.
21) Guerra, C. F.; Snijders, J. G.; te Velde, G.; Baerends, E. J. Theor.
(
(
(
2
(
Chem. Acc. 1998, 99 (6), 391−403.
(22) Becke, A. D. J. Chem. Phys. 1993, 98 (7), 5648−5652.
(23) Van Lenthe, E.; Baerends, E. J. J. Comput. Chem. 2003, 24 (9),
1
142−1156.
H
DOI: 10.1021/acs.joc.7b03146
J. Org. Chem. XXXX, XXX, XXX−XXX