Br?nsted Acid-Promoted One-Pot Synthesis of Chrysene Derivatives via Isochromenylium Intermediate Formed in Situ

Article abstract of DOI:10.1021/acs.joc.5b01219

Trifluoromethanesulfonic acid (HOTf) promoted cross-coupling of ortho-[2-(4-methoxylphenyl)-alkynyl]acetophenones with ortho-alkynylbenzaldehydes affording chrysene derivatives has been developed. The present cascade reaction provides a facile one-pot synthesis of multisubstituted chrysenes as well as naked chrysene under mild conditions. The mechanism experimental results demonstrate isochromenylium is a key intermediate for this transformation.

Full text of DOI:10.1021/acs.joc.5b01219

Article
pubs.acs.org/joc
Brønsted Acid-Promoted One-Pot Synthesis of Chrysene Derivatives
via Isochromenylium Intermediate Formed in Situ
Biao Guo, Yiming Zhou, Lei Zhang, and Ruimao Hua*
Department of Chemistry, Tsinghua University, Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of
Education, Beijing 100084, China
S
* Supporting Information
ABSTRACT: Trifluoromethanesulfonic acid (HOTf) pro-
moted cross-coupling of ortho-[2-(4-methoxylphenyl)-
alkynyl]acetophenones with ortho-alkynylbenzaldehydes af-
fording chrysene derivatives has been developed. The present
cascade reaction provides a facile one-pot synthesis of
multisubstituted chrysenes as well as naked chrysene under
mild conditions. The mechanism experimental results
demonstrate isochromenylium is a key intermediate for this
transformation.
cyclization of naphthylstyrenes or their analogues,13 1,5-
INTRODUCTION
■
naphthodiyne synthon formed in situ14 and the homocyclodime-
Isochromenyliums are reactive and versatile structures in
construction of complicated frameworks, and they have been
rization of 2-alkynyl-1-acetylbenzenes.15,16 The synthetic
method by the homocyclodimerization of 2-alkynyl-1-acetylben-
zenes is considered to be much more attractive due to the readily
available starting materials and easily introducing versatile
substituents. Therefore, Kuznetsov et al. reported an acid-
promoted homocyclodimerization of 2-alkynyl-1-acetylbenzenes
bearing electron-donating groups OMe on benzene ring to
obtain chrysene derivatives with low chemoselectivity via
isochromenylium intermediate (Scheme 1a),15 and Liu et al.
recently developed a Pt(II)-catalyzed hydrative homodimeriza-
tion of 2-alkynyl-1-acetylbenzenes having R group to be an alkyl
substituent (Scheme 1b).16a
In continuation of our studies on the application of o-alkynyl
aromatic carbonyl compounds in the synthesis of cyclic
compounds,17 very recently, we also reported a copper-catalyzed
homocyclodimerization of o-alkynylacetophenones affording
chrysene derivatives (Scheme 1c).16b However, it could only
construct the chrysene ring with the same substituents on the
benzene rings of A and D. With the purpose of developing an
another method to form the chrysene ring with easy introduction
of different substituents, we designed a cross-coupling of o-
alkynylacetophenones (1) and o-alkynylbenzaldehydes (2) with
controllable formation of isochromenylium from o-alkynylace-
tophenones (1) as intermediate, which further undergoes [4 + 2]
cycloaddition with o-alkynylbenzaldehydes (2) selectively
followed by intramolecular dehydration to construct chrysene
skeletons (Scheme 1d).
reported as important intermediates or starting materials in many
cascade reactions in the past decades.1−7 By treating o-
alkynylcarbonylbenzene precursors with transition metal cata-
lysts or other electrophiles (Au,1 Cu(II),2 Pd(II),3 W,4 Pt(II),5
IPy2BF4,6 I2,7 etc.), isochromenyliums can be formed in situ as
inseparable intermediates which are high reactive toward the
unsaturated carbon−carbon bonds. For example, isochromeny-
liums undergo [4 + 2] cycloaddition with alkynes to provide
multisubstituted naphthyl ketones, which are usually called
Asao−Yamamoto benzannulation.1,2 Multisubstituted naphtha-
lenes can also be obtained via the departure of carbonyl group in
the presence of Brønsted acid except for metal catalyst. Besides,
isochromenyliums can also be used as 1,3-dipolar species to react
with dipolarophiles via intramolecular [3 + 2] cycloaddition to
afford oxa-bridged ring compounds.8 In the presence of strong
Brønsted acid with bulky anion (HOTf,9 HBF4,10 etc.),
isochromenylium salts can be isolated with good yield, and the
presence of a large amount of anion is considered to be of benefit
to stabilize isochromenylium cation. In this respect, Swager9a and
Yao10 have done elegant pioneering work to get stable
isochromenylium salts and apply them in the organic synthesis,
but their approaches need large excess amount of Brønsted acid
and limit to the reactants, which must bear electron-donating
groups (EDGs) on the benzene ring.
On the other hand, chrysene derivatives have attracted
growing attention due to their potential applications in the
fields of electronic devices such as field-effect transistors (FETs)
and organic light-emitting diodes (OLEDs).11,12 Therefore, it is
significant and interesting to develop the different synthetic
methods to access multisubstituted chrysenes having substitu-
ents in requisite positions. Although there have several kinds of
synthetic routes to chrysene derivatives, including photo-
Received: May 30, 2015
© XXXX American Chemical Society
A
DOI: 10.1021/acs.joc.5b01219
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Article
Scheme 1. Synthesis of Chrysene Derivatives via 2-Alkynyl-1-acetylbenzenes
a
RESULTS AND DISCUSSION
Table 1. Reaction Optimization for the Synthesis of 3ac
■
The initial investigation was carried out by treating o-(2-
arylalkynyl)acetophenone 1 with o-(2-arylalkynyl)benzaldehyde
2c by dropping HOTf (1.6 equiv based on 2c) in DCM at 5 °C
for 10 min, then the reaction temperature was increased to 30 °C,
and the reaction mixture was further stirred for 18 h. It was found
that the use of o-(2-phenylalkynyl)acetophenone afforded trace
amount of 3ac (Table 1, entry 1), and its structure was confirmed
to be a chrysene derivative by X-ray crystallography (see
Supporting Information). However, the reactions of 1 bearing an
electron-poor alkynyl group (4-F-, 4-Cl- and 4-MeCO-phenyl-
alkynyl) gave no desired chrysene derivatives at all (Table 1,
entries 2−4). Fortunately, 1 having an electron-rich alkynyl
group reacted with 2c to afford 3ac as exclusive chrysene
derivative in low to moderate yields, depending on the property
of the electron donating groups (EDGs) (Table 1, entries 5−7),
and in the cases of o-[2-(para-methoxyphenyl)alkynyl]-
acetophenone and o-[2-(para-ethoxyphenyl)alkynyl]-
acetophenone used, 3ac could be isolated in 68 and 62% yields,
respectively. These results obviously indicated that the effect of
substituent group showed very important role to stabilize the
isochromenylium cation forming from 1 in situ, and the presence
of electron-rich group of para-methoxyphenyl bonded to
carbon−carbon triple bond is the key factor to stabilize the
isochromenylium cation, which further react with 2c to construct
chrysene ring. It should be also noted that the formation of the
b
entry
R
acid (equiv)
T (°C)
yield (%)
1
H
HOTf (1.6)
HOTf (1.6)
HOTf (1.6)
HOTf (1.6)
HOTf (1.6)
HOTf (1.6)
HOTf (1.6)
HOTf (1.6)
HOTf (1.0)
HOTf (2.0)
TFA (1.6)
30
30
30
30
30
30
30
40
30
30
30
30
30
trace
0
2
4-F
3
4-Cl
0
4
4-COMe
4-Me
0
5
8
6
4-OMe
4-OEt
68
62
52
37
60
0
7
8
4-OMe
4-OMe
4-OMe
4-OMe
4-OMe
4-OMe
9
10
11
12
13
CH3SO3H (1.6)
HBF4 (1.6)
0
29
a
Reaction conditions: 1 (0.3 mmol), 2c (0.2 mmol), DCM (3.0 mL),
b
18 h. Isolated yield of 3ac.
relative isochromenylium as orange precipitation was observed
by adding HOTf, when the substrates of 1 having R groups to be
OMe and OEt were used (vide Scheme 4). A higher temperature
B
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a
Scheme 2. Scope of o-Alkynebenzaldehydes for the Synthesis
of Chrysenes
Scheme 4. Synthesis of Isochromenylium Salts
a
a
Reaction conditions: 1 (1 mmol), HOTf (1.2 mmol), DCM (3 mL),
b
5 °C, 30 min. HOTf (2 mmol).
propose the mechanism for the formation of chrysene ring as
shown in Scheme 5.
Under the optimized conditions as indicated in entry 6 of
Table 1, the scope of the cross-coulping was investigated by using
a variety of o-alkynylbenzaldehydes 2 with o-[2-(para-
methoxyphenyl)alkynyl]acetophenone 1a. As concluded in
Scheme 2, substrate 2 bearing a terminal electron-rich
substituent (e.g., R1 = p-tolyl) or electron-withdrawing
substituent (e.g., R1 = Ph, p-FC6H4 or p-ClC6H4) underwent
the cross-co with 1a giving the corresponding chrysenes in
moderate to good yields (Scheme 2, 3aa−ad). Alternatively, the
investigation on the effect of substituent (R2) on the central
phenyl ring disclosed that substrates 2 bearing the functional
group at 5-position of the central phenyl ring afforded the
corresponding chrysenes in a higher yield (Scheme 2, 3ah vs 3al,
3ai−ak vs 3ae−ag). In addition, the electron effect trend of
substituents on the central phenyl ring of 2 was not observed.
To our delight, 2- ethynylbenzaldehyde (2m) also performed
the present cross-coupling with 1a to form the naked chrysene
a
Reaction conditions: 1a (0.6 mmol), 2 (0.4 mmol), HOTf (0.64
mmol), DCM (5 mL), 10−30 °C, 18 h, isolated yield of 3.
resulted in decline of yield (Table 1, entry 8). In addition, the
changes of the amount of HOTf led to slight decrease of yields
(Table 1, entries 9−10). Although the use of HBF4 also gave a fair
yield of 3ac (Table 1, entry 13), TFA and MeSO3H are
inappropriate for the present transformation, indicating that both
acid strength and anion volume are crucial to effect the formation
of 3ac (Table 1, entries 11−12).
More importantly, in the cases of 3ac formed, a compatible
amount of 4-methoxylbenzoic acid could be obtained from the
reaction mixture as byproduct, which is an important result to
a
Scheme 3. Scope of o-Alkyneacetophenone for the Synthesis of Chrysenes
a
b
Reaction conditions: 1 (0.6 mmol), 2 (0.4 mmol), HOTf (0.64 mmol), DCM (5 mL), 30 °C. 18 h. 40 °C. 28 h.
C
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Scheme 5. Proposed Mechanism
ring 3am in 38% isolated yield under the similar reaction
conditions. However, unfortunately, the reaction of 2 bearing a
terminal alkyl substituent (e.g., R1 = n-C4H9, 2n) underwent side
reaction, and the desired chrysene derivative was not obtained at
all. Therefore, the present reaction system could not be extended
to alkyl-substituted (R1) 2-alkynylbenzaldehydes.
We also examined the scope of the cross-coulping of 1 having
various R groups with 2c. As summarized in Scheme 3, the
reactions of substrates 1 bearing not only electron-withdrawing
groups (e.g., R = F (1b, 1e), Cl (1c) at 4- or 5-position), but also
electron-donating groups (e.g., R = Me (1d, 1f) at 4-position or
at both 4- and 5-positions) on the central phenyl ring afforded
the corresponding chrysene derivatives in moderate yields.
Interestingly, the present transformation could be applied to o-
alkynylacetonaphthone and the expected benzo[b]chrysene
derivative (3gc) was obtained in 70% yield, when the reaction
was performed with a higher temperature (40 °C) and in a
prolonged time (28 h).
In order to confirm the present transformation occurring via
the intermediate of isochromenylium, the reaction of 1a with
HOTf in DCM at 5 °C was examined, and the expected
isochromenylium triflate 4a was isolated as orange solid in 84%
yield. The 1H NMR and 13C NMR spectroscopic data
unambiguously indicated an identical isochromenylium structure
with OTf − anion confirmed by its 19F NMR showing a typical
signal at −79.7 ppm. In addition, we performed the reactions of
4a with 2c in the presence of HOTf or HOAc, and the expected
3ac was obtained in 73% and 55% respectively eq 1. These results
obviously demonstrated that isochromenylium 4a was the key
intermediate for the formation of chrysene ring.
isochromenylium. Not only substrates bearing alkyl was
compatible for the formation of isochromenylium, but also
substrates bearing an electron-withdrawing group fluorine could
afford satisfactory yield (Scheme 4).
On the basis of the known isochromenylium chemistry and
our experimental results, a plausible mechanism was proposed
for the formation of chrysene ring as depicted in Scheme 5. It
involves the formation of isochromenylium 4 promoted by
HOTf, and the Asao−Yamamoto type [4 + 2] cycloaddition of 4
with o-alkynylbenzaldehydes 2 to give intermediate A, which
undergoes the rearrangement reaction to give intermediate B
with the release of p-methoxybenzoic acid, the final intra-
molecular dehydration constructs the chrysene ring.
In addition, it is interesting to know the optical properties of
the synthesized chrysene derivatives 3 and isochromenylium
triflates 4. Therefore, some selected chrysene derivatives 3 and
isochromenylium triflates 4 were analyzed by UV−vis and
photoluminescence (PL) spectroscopy in solution. As shown in
Figure 1, compared to naked chrysene 3m, substituted chrysenes
3aa, 3ak and 3gc have bathochromic shifts in both absorption
and emission spectra to some extent. Their absorption maxima
are observed within the range 260−326 nm, and their emission
bands are within 360−450 nm. The UV−vis spectra of
isochromenylium triflate 4a and 4b have high-intensity
absorption between 330 and 350 nm and lower-intensity bands
In addition to the synthesis of 4a, we also investigated the
generality of other isochromenylium formation. It showed p-
alkoxyphenyl was a good substituent to stabilize the
D
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performed by flash column chromatography on silica gel with petroleum
ether/ethyl acetate (gradient mixture ratio from 100:0 to 98:5) as eluent
to afford 2-(4-methoxyphenylethynyl)acetophenone 1a in 80% yield
(2000.0 mg).
o-Alkynylbenzaldehydes were prepared under the similar procedure
by the cross-coupling reactions of 2-bromobenzaldehydes with terminal
aryl acetylenes.
Typical Experimental Procedure for Synthesis of 3ac. To a 25 mL
tube equipped with a magnetic stirrer, 1a (150.0 mg, 0.6 mmol), DCM
(3 mL) and 2c (90.0 mg, 0.4 mmol) were added sequentially at 0−5 °C
in an ice bath, and then HOTf (0.056 mL, 0.64 mmol) was slowly added
with a pipet. Kept the reaction mixture at 5 °C and stirred for 20 min.
The tube was then sealed and stirred at 30 °C in an oil bath for 18 h.
After removal of the solvent under reduced pressure, purification was
performed by flash column chromatography on silica gel with petroleum
ether/DCM (gradient mixture ratio from 100:0 to 98:2) as eluent to
afford 5-(4-fluorophenyl)chrysene 3ac in 90% yield (87.0 mg).
Typical Experimental Procedure for Synthesis of 4a. To a solution
of 1a (250.0 mg, 1.0 mmol) in DCM (3 mL) was added HOTf (0.105
mL, 1.2 mmol) at 0−5 °C in an ice bath. The solution was stirred at 0−5
°C for 30 min. The solids were collected by simple filtration, washed
with ether and dried under a vacuum, affording the pure orange solid 3-
(4-methoxyphenyl)-1-methylisochromenylium trifluoromethanesulfo-
nate 4a in 84% yield (336.0 mg).
Characterization Data of the Chrysene Derivatives. 5-Phenyl-
1
chrysene (3aa). White solid (60%, 73.0 mg); mp 182−184 °C; H
NMR (400 MHz, CDCl3) δ 8.80 (d, J = 8.8 Hz, 2H), 8.04 (d, J = 8.9 Hz,
1H), 7.98−7.96 (m, 2H), 7.89 (s, 1H), 7.87 (d, J = 8.9 Hz, 1H), 7.73 (dd
≈ t, J = 7.3 Hz, 1H), 7.67 (dd ≈ t, J = 7.3 Hz, 1H), 7.50 (m, 6H), 7.18 (dd
≈ t, J = 7.6 Hz, 1H); 13C NMR (101 MHz, CDCl3) δ 145.7, 138.5, 133.5,
131.6, 131.0, 130.7, 130.2, 130.1, 129.1, 129.0, 128.9, 128.5, 128.3, 128.2,
127.5, 127.1, 126.9, 126.8, 125.9, 124.7, 123.2, 121.4; HRMS (APPI-
Orbitrap) m/z [M + H]+ calcd for C24H17 305.1325, found 305.1315.
5-(p-Tolyl)chrysene (3ab). White solid (56%, 71.0 mg); mp 156−
158 °C; 1H NMR (400 MHz, CDCl3) δ 8.69 (d, J = 8.9 Hz, 2H), 7.96−
7.83 (m, 4H), 7.82−7.77 (m, 1H), 7.61 (m, 2H), 7.43 (m, 1H), 7.33 (m,
2H), 7.25 (d, J = 7.8 Hz, 2H), 7.14 (m, 1H), 2.45 (s, 3H); 13C NMR
(101 MHz, CDCl3) δ 142.7, 138.5, 136.7, 133.4, 131.6, 131.0, 130.8,
130.1, 130.0, 129.7, 129.0, 128.4, 128.2, 128.1, 127.6, 126.8, 126.7, 125.8,
124.6, 123.2, 121.3, 21.4; HRMS (APPI-Orbitrap) m/z [M + H]+ calcd
for C25H19 319.1481, found 319.1472.
Figure 1. Normalized UV−vis and photoluminescence (PL) spectra of
selected chrysene derivatives 3 and isochromenylium triflate 4 in DCM
(1.0 × 10 −5 M).
between 420 and 500 nm, and their emission maxima are
observed within the range 540−560 nm.
5-(4-Fluorophenyl)chrysene (3ac). White solid (68%, 87.0 mg); mp
198−200 °C; 1H NMR (400 MHz, CDCl3) δ 8.77 (d, J = 8.9 Hz, 2H),
8.02 (d, J = 8.8 Hz, 1H), 7.97−7.92 (m, 2H), 7.81 (s, 1H), 7.79 (d, J = 8.8
Hz, 1H), 7.72 (m, 1H), 7.66 (m, 1H), 7.51−7.41 (m, 3H), 7.22−7.14
(m, 3H); 13C NMR (101 MHz, CDCl3) δ 162.3 (d, J 1C−F = 246.0 Hz),
CONCLUSION
■
In conclusion, we have developed a new synthetic method access
to chrysene derivatives in moderate to good yields by a simple
one-pot cross-coulping of o-alkynylacetophenones and o-
alkynylbenzaldehydes in the presence of TfOH with high
chemoselectivity. On the basis of the controlled experimental
results, the formation of chrysene ring is proposed including the
formation of isochromenylium triflate as the key intermediates.
141.6 (d, J 4C−F = 3.4 Hz), 137.4, 133.5, 131.5, 131.1, 130.7 (d, J 3
=
C−F
7.8 Hz), 130.6, 130.2, 130.1, 128.7, 128.48, 128.4, 128.3, 127.5, 127.0,
2
126.9, 126.0, 124.8, 123.3, 121.4, 116.0 (d, J
= 21.5 Hz); HRMS
C−F
(APPI-Orbitrap) m/z [M + H]+ calcd for C24H16F 323.1230, found
323.1237.
5-(4-Chlorophenyl)chrysene (3ad). White solid (65%, 88.0 mg); mp
154−156 °C; 1H NMR (400 MHz, CDCl3) δ 8.76 (d, J = 8.8 Hz, 2H),
8.01 (d, J = 8.8 Hz, 1H), 7.95 (d, J = 8.0 Hz, 2H), 7.84 (d, J = 8.8 Hz,
1H), 7.80 (s, 1H), 7.72 (t, J = 7.2 Hz, 1H), 7.66 (m, 1H), 7.52 (d, J = 7.2
Hz, 1H), 7.48 (d, J = 8.4 Hz, 2H), 7.41 (d, J = 8.4 Hz, 2H), 7.23 (m, 1H);
13C NMR (101 MHz, CDCl3) δ 144.1, 137.1, 133.5, 133.1, 131.4, 131.0,
130.4, 130.39, 130.2, 130.2, 129.2, 128.8, 128.5, 128.4, 128.3, 127.2,
127.0, 126.96, 126.0, 124.8, 123.2, 121.3; HRMS (APPI-Orbitrap) m/z
[M + H]+ calcd for C24H16Cl 339.0935, found 339.0925.
3-Chloro-5-phenylchrysene (3ae). White solid (53%, 72.0 mg); mp
172−176 °C; 1H NMR (400 MHz, CDCl3) δ 8.73 (d, J = 7.8 Hz, 1H),
8.72 (d, J = 8.9 Hz, 1H), 7.95 (d, J = 7.8 Hz, 1H), 7.92 (d, J = 8.9 Hz,
1H), 7.86 (s, 1H), 7.81 (d, J = 8.5 Hz, 1H), 7.75−7.64 (m, 3H), 7.55−
7.53 (m, 2H), 7.47−7.44 (m, 1H), 7.41 (m, 1H); 13C NMR (101 MHz,
CDCl3) δ 144.8, 138.3, 131.7, 131.6, 131.5, 131.0, 130.6, 130.5, 130.0,
129.5, 129.2, 129.0, 128.5, 128.4, 127.5, 127.48, 127.2, 127.0, 126.6,
126.4, 123.3, 121.6; HRMS (APPI-Orbitrap) m/z [M + H]+ calcd for
C24H16Cl 339.0935, found 339.0927.
EXPERIMENTAL SECTION
■
General Methods. All commercial reagents are analytically pure and
used without further purification. Nuclear magnetic resonance (NMR)
spectra were recorded using CDCl3 as solvent at 298 K. 1H NMR (400
MHz) chemical shifts (δ) were referenced to internal standard TMS (for
1H, δ = 0.00 ppm). 13C NMR (101 MHz) chemical shifts were
referenced to internal solvent CDCl3 (for 13C, δ = 77.16 ppm). HRMS
experiments were performed on a high resolution magnetic sector mass
spectrometer. The melting points are uncorrected.
Typical Experimental Procedure for Synthesis of 1a. To a 50 mL
tube equipped with a magnetic stirrer, 2-bromoacetophenone (1990.0
mg, 10.0 mmol), Pd(PPh3)2Cl2 (70.1 mg, 0.1 mmol), CuI (38.1 mg, 0.2
mmol), NEt3 (20 mL), THF (10 mL), and 4-methoxyphenylacetylene
(1980.0 mg, 15 mmol) were added sequentially under N2 atmosphere.
The tube was sealed and stirred at 90 °C in an oil bath for 24 h. After
removal of the solvent under reduced pressure, purification was
E
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3-Methyl-5-phenylchrysene (3af). White solid (54%, 68.0 mg); mp
160−162 °C; 1H NMR (400 MHz, CDCl3) δ 8.68 (d, J = 8.2 Hz, 1H),
8.61 (d, J = 8.9 Hz, 1H), 7.90−7.85 (m, 2H), 7.78 (s, 1H), 7.74 (d, J = 8.2
Hz, 1H), 7.61 (dd, J = 7.0, 1.5 Hz, 1H), 7.55 (dd, J = 7.0, 1.5 Hz, 1H),
7.45 (s, 1H), 7.42 (m, 5H), 7.23 (dd, J = 8.1, 1.2 Hz, 1H), 2.09 (s, 3H);
13C NMR (101 MHz, CDCl3) δ 145.7, 138.6, 134.1, 131.5, 131.5, 130.7,
130.5, 130.2, 130.2, 129.2, 129.0, 128.9, 128.4, 128.0, 127.9, 127.6, 127.2,
127.0, 126.8, 126.7, 123.3, 120.4, 22.1; HRMS (APPI-Orbitrap) m/z [M
+ H]+ calcd for C25H19 319.1481, found 319.1470.
2-Fluoro-11-(4-fluorophenyl)chrysene (3bc). White solid (51%,
69.0 mg); mp 146−148 °C; 1H NMR (400 MHz, CDCl3) δ 8.69 (d, J =
9.2 Hz, 1H), 8.68 (d, J = 9.2 Hz, 1H), 8.63 (d, J = 9.1 Hz, 1H), 7.99 (d, J
= 9.1 Hz, 1H), 7.93(dd ≈ t, J = 7.3 Hz, 1H), 7.74 (dd ≈ t, J = 8.7 Hz, 1H),
7.69 (s, 1H), 7.54−7.36 (m, 5H), 7.22−7.14 (m, 3H); 13C NMR (101
1
1
MHz, CDCl3) δ162.4 (d, J C−F= 246.5 Hz), 161.5 (d, J
= 247.2
C−F
Hz), 141.2 (d, J 4C−F = 3.3 Hz), 138.7, 133.3, 132.7 (d, J 3C−F = 8.8 Hz),
130.6, 130.5, 130.5, 130.2, 130.1 (d, J 4C−F = 3.9 Hz), 128.7, 128.6, 128.4,
126.9 (d, J 3C−F = 8.7 Hz), 126.0, 125.8 (d, J 3C−F = 8.8 Hz), 125.0, 121.1,
116.3 (d, J 2C−F = 25.2 Hz), 116.0 (d, J 2C−F = 21.8 Hz), 111.9 (d, J 2
=
3-Methoxy-5-phenylchrysene (3ag). White solid (43%, 57.0 mg);
mp 192−196 °C; 1H NMR (400 MHz, CDCl3) δ 8.78 (d, J = 8.3 Hz,
1H), 8.66 (d, J = 8.8 Hz, 1H), 7.98−7.93 (m, 2H), 7.82 (d, J = 8.8 Hz,
1H), 7.80 (s, 1H), 7.74−7.68 (m, 1H), 7.66−7.62 (m, 1H), 7.55−7.48
(m, 4H), 7.42 (m, 1H), 7.37 (d, J = 2.3 Hz, 1H), 7.11 (dd, J = 8.7, 2.5 Hz,
1H), 3.25 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 156.6, 146.1, 138.5,
131.9, 131.5, 130.6, 130.3, 129.6, 129.4, 129.2, 128.5, 128.3, 127.8, 127.0,
126.9, 126.8, 126.7, 123.4, 119.1, 117.9, 109.2, 54.4; HRMS (APPI-
Orbitrap) m/z [M + H]+ calcd for C25H19O 335.1430, found 335.1421.
2-Fluoro-5-phenylchrysene (3ah). White solid (73%, 94.0 mg); mp
178−180 °C; 1H NMR (400 MHz, CDCl3) δ 8.77 (d, J = 9.1 Hz, 1H),
8.74 (d, J = 8.4 Hz, 1H), 7.96 (m, 1H), 7.92 (d, J = 9.1 Hz, 1H), 7.86 (s,
1H), 7.80 (m, 1H), 7.73−7.69 (m, 1H), 7.69−7.63 (m, 1H), 7.54 (m,
1H), 7.52−7.43 (m, 5H), 6.90 (m, 1H); 13C NMR (101 MHz, CDCl3) δ
160.4 (d, J 1C−F = 247.4 Hz), 145.4, 138.1, 134.9 (d, J 3C−F = 8.7 Hz),
131.3 (d, J 3C−F = 8.8 Hz), 131.2, 130.1, 129.5, 129.2, 129.1, 128.5, 127.6,
127.4 (d, J 4C−F = 3.5 Hz), 127.3, 127.0, 126.9, 123.1, 122.6, 114.1, 113.8,
113.9 (d, J 2C−F = 23.2 Hz), 111.7 (d, J 2C−F = 20.0 Hz); HRMS (APPI-
Orbitrap) m/z [M + H]+ calcd for C24H16F 323.123, found 323.1235.
2-Chloro-5-phenylchrysene(3ai). White solid (62%, 84.0 mg); mp
164−166 °C; 1H NMR (400 MHz, CDCl3) δ 8.76 (d, J = 9.2 Hz, 1H),
8.73 (d, J = 8.4 Hz, 1H), 7.95 (d, J = 7.5 Hz, 1H), 7.88 (m, 1H), 7.86 (d, J
= 9.5 Hz, 2H), 7.74−7.62 (m, 3H), 7.53−7.42 (m, 5H), 7.07 (m, 1H);
13C NMR (101 MHz, CDCl3) δ 145.2, 138.2, 134.5, 131.6, 131.6, 131.3,
130.4, 130.0, 129.2, 129.1, 129.0, 128.5, 137.4, 127.3, 127.1, 127.0, 126.9,
125.2, 123.2, 122.6; HRMS (APPI-Orbitrap) m/z [M + H]+ calcd for
C24H16Cl 339.0935, found 339.0924.
2-Methyl-5-phenylchrysene (3aj). White solid (76%, 96.0 mg); mp
142−144 °C; 1H NMR (400 MHz, CDCl3) δ 8.64 (m, 2H), 7.83 (t, J =
9.2 Hz, 2H), 7.75 (s, 1H), 7.65−7.57 (m, 3H), 7.53 (t, J = 7.3 Hz, 1H),
7.39 (m, 5H), 6.91 (d, J = 8.8 Hz, 1H), 2.39 (s, 3H); 13C NMR (101
MHz, CDCl3) δ 145.7, 138.4, 135.5, 133.7, 131.4, 130.8, 130.2, 129.6,
129.1, 129.0, 128.7, 128.6, 128.5, 127.8, 127.7, 127.5, 127.0, 126.7,
126.68, 126.6, 123.1, 121.3, 21.3; HRMS (APPI-Orbitrap) m/z [M +
H]+ calcd for C25H19 319.1481, found 319.1473.
2-Methoxy-5-phenylchrysene (3ak). White solid (51%, 68.0 mg);
mp 192−196 °C; 1H NMR (400 MHz, CDCl3) δ 8.76 (d, J = 9.2 Hz,
2H), 7.96−7.91 (m, 2H), 7.83 (s, 1H), 7.73−7.67 (m, 2H), 7.66−7.60
(m, 1H), 7.53−7.43 (m, 5H), 7.28 (d, J = 2.8 Hz, 1H), 6.80 (dd, J = 9.5,
2.8 Hz, 1H), 3.93 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 157.4, 145.7,
138.2, 135.1, 131.2, 131.0, 130.4, 130.3, 129.1, 129.0, 128.7, 128., 49
127.8, 127.6, 127.1, 126.8, 126.5, 125.3, 123.0, 121.9, 115.7, 107.6, 55.4;
HRMS (APPI-Orbitrap) m/z [M + H]+ calcd for C25H19O 335.1430,
found 335.1418.
C−F
20.2 Hz); HRMS (APPI-Orbitrap) m/z [M + H]+ calcd for C24H15F2
341.1136, found 341.1144.
2-Chloro-11-(4-fluorophenyl)chrysene (3cc). White solid (65%,
92.0 mg); mp 186−188 °C; 1H NMR (400 MHz, CDCl3) δ 8.52 (d, J =
9.0 Hz, 1H), 8.51 (d, J = 9.0 Hz, 1H), 7.91 (d, J = 9.0 Hz, 1H), 7.88−7.83
(m, 1H), 7.78 (d, J = 2.2 Hz, 1H), 7.67 (d, J = 8.7 Hz, 1H), 7.56 (s, 1H),
7.52 (dd, J = 9.0, 2.2 Hz, 1H), 7.46−7.40 (m, 1H), 7.33−7.27 (m, 2H),
7.16−7.07 (m, 3H); 13C NMR (101 MHz, CDCl3) δ 162.4 (d, J 1
=
C−F
246.6 Hz), 141.1 (d, J 4C−F = 3.5 Hz), 138.6, 133.5, 132.7, 132.3, 130.6
3
(d, J
= 7.9 Hz), 130.4, 129.9, 129.8, 128.7, 128.5, 128.4, 127.4,
C−F
2
127.1, 126.1, 126.0, 125.0, 121.0, 116.0 (d, J
= 21.5 Hz); HRMS
C−F
(APPI-Orbitrap) m/z [M + H]+ calcd for C24H15ClF 357.0840, found
357.0829.
2-Methyl-11-(4-fluorophenyl)chrysene (3dc). White solid (40%,
54.0 mg); mp 192−194 °C; 1H NMR (400 MHz, CDCl3) δ 8.69 (d, J =
9.0 Hz, 1H), 8.61 (d, J = 8.6 Hz, 1H), 7.96 (d, J = 9.0 Hz, 1H), 7.89 (d, J
= 7.9 Hz, 1H), 7.72 (d, J = 8.7 Hz, 1H), 7.68 (d, J = 5.9 Hz, 2H), 7.50
(dd, J = 8.6, 1.5 Hz, 1H), 7.45−7.35 (m, 3H), 7.18−7.08 (m, 3H), 2.56
(s, 3H); 13C NMR (101 MHz, CDCl3) δ 162.3 (d, J 1C−F = 246.0 Hz),
141.7 (d, J 4C−F = 3.3 Hz), 137.4, 136.8, 133.4, 131.7, 130.8, 130.7 (d, J
3
C−F = 7.7 Hz), 130.6, 130.2, 129.0, 128.7, 128.4, 128.23, 128.19, 127.8,
2
126.9, 125.7, 124.7, 123.2, 121.4, 116.0 (d, J
= 21.2 Hz). 21.6;
C−F
HRMS (APPI-Orbitrap) m/z [M + H]+ calcd for C25H18F 337.1387,
found 337.1390.
3-Fluoro-11-(4-fluorophenyl)chrysene (3ec). White solid (47%,
64.0 mg); mp 186−188 °C; 1H NMR (400 MHz, CDCl3) δ 8.56 (d, J =
9.0 Hz, 1H), 8.34 (m, 1H), 7.99 (d, J = 9.0 Hz, 1H), 7.93 (t, J = 8.4 Hz,
1H), 7.89 (d, J = 6.0 Hz, 1H), 7.77 (d, J = 8.4 Hz, 1H), 7.76 (s, 1H), 7.49
(dd ≈ t, J = 7.4 Hz, 1H), 7.39 (m, 3H), 7.18 m, 3H); 13C NMR (101
MHz, CDCl3) δ 162.3 (d, J 1C−F = 246.4 Hz), 161.8 (d, J 1C−F = 245.5
Hz), 141.4 (d, J 4C−F = 3.3 Hz), 136.7, 133.7, 131.5 (d, J 3C−F = 8.5 Hz),
130.6 (d, J 3C−F = 8.1 Hz), 130.5, 130.4, 129.5 (d, J 4C−F = 4.7 Hz), 128.8,
128.4 (d, J 3C−F = 7.4 Hz), 128.3, 128.0, 126.3, 124.9, 121.3, 116.5 (d, J
2
C−F = 24.4 Hz), 116.0 (d, J 2C−F = 21.4 Hz), 108.0 (d, J 2C−F = 22.5 Hz);
HRMS (APPI-Orbitrap) m/z [M + H]+ calcd for C24H15F2 341.1136,
found 341.1142.
11-(4-Fluorophenyl)-2,3-dimethylchrysene (3 fc). White solid
1
(36%, 50.0 mg); mp 200−202 °C; H NMR (400 MHz, CDCl3) δ
8.74 (d, J = 9.1 Hz, 1H), 8.51 (s, 1H), 7.98 (d, J = 9.1 Hz, 1H), 7.93 (d, J
= 7.9 Hz, 1H), 7.77 (d, J = 8.7 Hz, 1H), 7.70 (s, 1H), 7.68 (s, 1H), 7.50−
7.39 (m, 3H), 7.49−7.38 (m, 3H), 7.22−7.13 (m, 3H), 7.22−7.13 (m,
3H), 2.59 (s, 3H), 2.50 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 162.2
(d, J = 245.7 Hz), 141.9 (d, J = 3.5 Hz), 136.6, 136.5, 133.3, 130.7 (d, J =
7.6 Hz), 130.6, 130.5, 130.2, 129.7, 128.8, 128.7, 128.4, 128.3, 127.9,
126.9, 125.6, 124.6, 123.3, 121.4, 115.9 (d, J = 21.2 Hz), 21.0, 20.1;
HRMS (APPI-Orbitrap) m/z [M + H]+ calcd for C26H20F 351.1543,
found 351.1534.
1-Fluoro-5-phenylchrysene (3al). White solid (49%, 63.0 mg); mp
124−126 °C; 1H NMR (400 MHz, CDCl3) δ 8.84 (d, J = 9.3 Hz, 1H),
8.78 (d, J = 8.3 Hz, 1H), 8.34 (d, J = 9.3 Hz, 1H), 7.96 (dd, J = 7.9, 1.1
Hz, 1H), 7.87 (s, 1H), 7.74−7.70 (m, 1H), 7.70−7.63 (m, 1H), 7.58 (d,
J = 8.7 Hz, 1H), 7.54−7.43 (m, 5H), 7.18−7.12 (m, 1H), 7.09−7.02 (m,
5-(4-Fluorophenyl)benzo[c]tetraphene (3gc). White solid (70%,
1040.0 mg); mp 198−200 °C; 1H NMR (400 MHz, CDCl3) δ 9.14 (s,
1H), 8.83 (d, J = 9.0 Hz, 1H), 8.33 (s, 1H), 8.12−8.07 (m, 1H), 7.99 (dd,
J = 9.3, 2.7 Hz, 2H), 7.90 (d, J = 7.6 Hz, 1H), 7.77 (s, 1H), 7.69 (d, J = 8.7
Hz, 1H), 7.55−7.48 (m, 2H), 7.46−7.41 (m, 1H), 7.40−7.33 (m, 2H),
1
1H); 13C NMR (101 MHz, CDCl3) δ 158.8 (d, J
= 249.1 Hz),
C−F
145.4, 138.4, 132.3 (d, J 4C−F = 3.6 Hz), 131.7, 131.4, 130.4, 130.0, 129.1,
129.0, 128.5, 127.2, 127.0, 124.82, 124.78, 124.4 (d, J
3
= 8.6 Hz),
C−F
C−F
2
3
123.3, 123.2 (d, J
= 15.5 Hz), 121.9, 119.8 (d, J
= 7.9 Hz),
C−F
109.90 (d, J 2C−F = 19.9 Hz); HRMS (APPI-Orbitrap) m/z [M + H]+
calcd for C24H16F 323.123, found 323.1237.
7.18−7.08 (m, 3H); 13C NMR (101 MHz, CDCl3) δ 162.2 (d, J 1
=
C−F
246.1 Hz), 141.5 (d, J 4C−F = 3.1 Hz), 137.1, 133.7, 132.2, 131.3, 130.5,
Chrysene (3am). White solid (38%, 35.0 mg); mp 140−144 °C; 1H
NMR (400 MHz, CDCl3) δ 8.80 (d, J = 8.4 Hz, 2H), 8.74 (d, J = 8.8 Hz,
2H), 8.02 (d, J = 8.8 Hz, 2H), 8.01 (d, J = 8.4 Hz, 2H), 7.75−7.69 (m,
2H), 7.67−7.62 (m, 2H); 13C NMR (101 MHz, CDCl3) δ 132.3, 130.7,
128.7, 128.4, 127.5, 126.8, 126.5, 123.3, 121.4; HRMS (APPI-Orbitrap)
m/z [M + H]+ calcd for C18H13 229.1012, found 229.1003.
130.5 (d, J
= 7.5 Hz), 130.3, 130.0, 128.83, 128.8, 128.7, 128.4,
3
C−F
127.8, 127.3, 126.7, 126.1, 125.9, 125.8, 124.7, 122.3, 121.5, 115.9 (d, J
2
= 21.4 Hz); HRMS (APPI-Orbitrap) m/z [M + H]+ calcd for
C−F
C28H18F 373.1387, found 373.1375.
3-(4-Methoxyphenyl)-1-methylisochromenylium trifluorometha-
nesulfonate (4a). Orange solid (84%, 336.0 mg); mp 150−154 °C; 1H
F
DOI: 10.1021/acs.joc.5b01219
J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Article
NMR (400 MHz, CDCl3, a drop of CF3COOH) δ 8.48 (d, J = 8.6 Hz,
1H), 8.37 (s, 1H), 8.29−8.23 (m, 1H), 8.12 (d, J = 8.3 Hz, 1H), 8.04 (d, J
= 8.9 Hz, 2H), 7.96−7.89 (m, 1H), 7.07 (d, J = 8.9 Hz, 2H), 3.89 (s, 3H),
3.50 (s, 3H); 13C NMR (101 MHz, CDCl3, a drop of CF3COOH) δ
185.4, 164.2, 162.4, 143.54, 143.1, 132.3, 130.4, 128.9, 128.3, 123.4,
120.7, δ 119.9 (q, J 1C−F = 318.2 Hz), 115.6, 113.5, 55.8, 20.7; 19F NMR
(565 MHz, CDCl3, a drop of CF3COOH as internal standard) δ −79.7.
HRMS (ESI-TOF) m/z [M − OTf]+ calcd for C17H15O2 251.1067,
found 251.1068.
6-Fluoro-3-(4-methoxyphenyl)-1-methylisochromenylium tri-
fluoromethanesulfonate (4b). Orange solid (82%, 343.0 mg); mp
160−164 °C; 1H NMR (400 MHz, CDCl3, a drop of CF3COOH) δ 8.60
(m, 1H), 8.30 (s, 1H), 8.02 (d, J = 8.9 Hz, 2H), 7.69 (dd, J = 8.3, 2.2 Hz,
1H), 7.63 (m, 1H), 7.06 (d, J = 8.9 Hz, 2H), 3.89 (s, 3H), 3.46 (s, 3H);
13C NMR (101 MHz, CDCl3, a drop of CF3COOH) δ 184.7, 171.4 (d, J
REFERENCES
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1
C−F = 276.0 Hz), 164.4, 162.6, 146.4 (d, J 3C−F = 15.1 Hz), 135.4 (d, J
3
C−F = 12.9 Hz), 129.1, 123.3 (d, J 2C−F = 26.2 Hz), 120.9, 120.3, 119.8
(q, J 1C−F = 318.2 Hz), 115.6, 112.6, 112.5 (d, J 2C−F = 19.6 Hz), 55.8,
20.7; HRMS (ESI-TOF) m/z [M − OTf]+ calcd for C17H14FO2
269.0972, found 269.0976.
3-(4-Methoxyphenyl)-1,6-dimethylisochromenylium trifluorome-
thanesulfonate (4d). Orange solid (81%, 335.0 mg); mp 150−154 °C;
1H NMR (400 MHz, CDCl3, a drop of CF3COOH) δ 8.37 (d, J = 8.8 Hz,
̈
1H), 8.21 (s, 1H), 8.02 (d, J = 8.9 Hz, 2H), 7.89 (s, 1H), 7.77 (d, J = 8.8
Hz, 1H), 7.10 (d, J = 8.9 Hz, 2H), 3.91 (s, 3H), 3.44 (s, 3H), 2.71 (s,
3H); 13C NMR (101 MHz, CDCl3, a drop of CF3COOH) δ 183.7,
164.1, 162.2, 158.3, 143.2, 134.8, 130.1, 128.7, 127.2, 121.8, 120.9, 119.8
(q, J 1C−F = 317.9 Hz), 115.6, 112.4, 55.8, 23.5, 20.3; HRMS (ESI-TOF)
m/z [M − OTf]+ calcd for C18H17O2 265.1223, found 265.1224.
7-Fluoro-3-(4-methoxyphenyl)-1-methylisochromenylium tri-
fluoromethanesulfonate (4e). Orange solid (77%, 322.0 mg); mp
154−156 °C; 1H NMR (400 MHz, CDCl3, a drop of CF3COOH) δ 8.44
(s, 1H), 8.23−8.15 (m, 1H), 8.07−7.95 (m, 4H), 7.07 (d, J = 8.9 Hz,
2H), 3.89 (s, 3H), 3.45 (s, 3H); 13C NMR (101 MHz, CDCl3, a drop of
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(6) (a) Barluenga, J.; Vaz
J. Am. Chem. Soc. 2003, 125, 9028. (b) Barluenga, J.; Vaz
́
quez-Villa, H.; Ballesteros, A.; Gonzal
́
ez, J. M.
quez-Villa, H.;
́
Ballesteros, A.; Gonzal
(c) Barluenga, J.; Vaz
Gonzal
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(b) Yue, D.; Ca, N. D.; Larock, R. C. J. Org. Chem. 2006, 71, 3381.
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́
́
(8) Kim, J. H.; Ray, D.; Hong, C. S.; Hana, J. W.; Oh, C. H. Chem.
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CF3COOH) δ 184.4 (d, J 4C−F = 6.8 Hz), 164.4, 162.9, 162.8 (d, J 1
=
(9) (a) Tovar, J. D.; Swager, T. M. J. Org. Chem. 1999, 64, 6499.
(b) Sato, K.; Menggenbateer; Kubota, T.; Asao, N. Tetrahedron 2008,
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2011, 24, 345.
C−F
260.3 Hz), 141.0, 134.1 (d, J 2C−F = 26.3 Hz), 131.7 (d, J 3C−F = 8.9 Hz),
129.0, 124.6 (d, J 3C−F = 10.1 Hz), 120.5, 119.8 (d, J 1C−F = 318.2 Hz),
115.7, 113.8, 112.7 (d, J 2C−F = 23.8 Hz), 55.8, 20.9; HRMS (ESI-TOF)
m/z [M − OTf]+ calcd for C17H14FO2 269.0972, found 269.0976.
3-(4-Methoxyphenyl)-1-methylbenzo[g]isochromen-2-ium tri-
fluoromethanesulfonate (4g). Atropurpureus solid (80%, 360.0 mg);
mp 132−134 °C; 1H NMR (400 MHz, CDCl3, a drop of CF3COOH) δ
9.38 (s, 1H), 8.49 (s, 1H), 8.24 (m, 2H), 8.07 (d, J = 8.6 Hz, 1H), 7.95
(d, J = 8.9 Hz, 2H), 7.92−7.84 (m, 1H), 7.76−7.68 (m, 1H), 7.06 (d, J =
8.9 Hz, 2H), 3.87 (s, 3H), 3.67 (s, 3H); 13C NMR (101 MHz, CDCl3, a
drop of CF3COOH) δ 190.4, 163.1, 157.7, 142.1, 136.6, 135.6, 134.3,
133.2, 131.5, 129.8, 128.6, 127.9, 126.7, 121.1, 120.4, 119.8 (d, J 1
=
C−F
317.8 Hz), 115.5, 111.7, 55.7, 21.6; HRMS (ESI-TOF) m/z [M − OTf]+
calcd for C21H17O2 301.1223, found 301.1225.
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ASSOCIATED CONTENT
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* Supporting Information
1
Copies of H and 13C NMR charts of all products and X-ray
structural details of 3ac. The Supporting Information is available
free of charge on the ACS Publications website at DOI: 10.1021/
acs.joc.5b01219.
AUTHOR INFORMATION
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Corresponding Author
*E-mail: ruimao@mail.tsinghua.edu.cn.
(16) (a) Das, A.; Liao, H.-H.; Liu, R.-S. J. Org. Chem. 2007, 72, 9214.
(b) Guo, B.; Zheng, L.; Yang, L.; Hua, R. J. Org. Chem. 2014, 79, 4352.
(17) Ju, J.; Hua, R. Curr. Org. Synth. 2013, 10, 328.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
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This project was supported by National Natural Science
Foundation of China (21473097, 21273125).
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DOI: 10.1021/acs.joc.5b01219
J. Org. Chem. XXXX, XXX, XXX−XXX