Two-step synthesis of π-expanded maleimides from 3,4-diphenylfuran-2(5 H)-ones

Article abstract of DOI:10.1021/acs.joc.9b01792

An efficient two-step synthesis of -expanded maleimide derivatives was reported, which proceeded via a photoinduced dehydrogenative annulation of 3,4-diphenylfuran-2(5H)-ones in EtOH at room temperature for 5 h under an argon atmosphere, followed by inter

Full text of DOI:10.1021/acs.joc.9b01792

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Article
Two-Step Synthesis of #-Expanded
Maleimides from 3,4-Diphenylfuran-2(5H)-ones
Yang Kang, Wei Zhang, Tao Wang, Yong Liang, and Zunting Zhang
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.9b01792 • Publication Date (Web): 13 Sep 2019
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Two-Step Synthesis of π-Expanded Maleimides from
3,4-Diphenylfuran-2(5H)-ones
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Yang Kang, Wei Zhang, Tao Wang, Yong Liang,† Zunting Zhang*
Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry,
National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest of China,
and School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, People’s
Republic of China.
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R3
N
O
O
O
O
O
O
DBU, R3NH2
DMF, 120 oC, O2
hv, r.t.
EtOH, Ar
- H2
R2
R2
R1
R2
R1
R1
Without any metal catalyst
Available starting materials
π-Expanded syetems
R1=H, F, Cl, CN, OMe.
R2=H, CN, Cl, F, OMe, CF3, t-Bu.
R3NH2=Bn, H, i-Pr.
High fluorescence quantum yields
ABSTRACT: An efficient two-step synthesis of π-expanded maleimide derivatives was reported,
which proceeded via a photoinduced dehydrogenative annulation of 3,4-diphenylfuran-2(5H)-ones
in EtOH at room temperature for 5 h under the argon atmosphere, followed by interaction with
primary amine in the presence of DBU and O2. The synthesis of highly conjugated maleimides
demonstrated that 3,4-diphenylfuran-2(5H)-ones were useful precursors for synthesis of
π-expanded lactones and π-expanded maleimides with no need of transition metal catalyst.
Additionally, the fluorescent properties of the highly conjugated maleimides were characterized
and possessed high fluorescence quantum yields in dichloromethane solution.
INTRODUCTION
In recent years, photochemical reactions have received increased attention due to the
demands of the green concept of energy saving, high atom efficiency and environmental
2
protection.1, They have been also provided convenient access to obtain the phenanthrene
derivatives and polycyclic aromatic hydrocarbons (PAHs), which are hard to access by
non-photochemical approaches.3, 4
Maleimides have been attracted considerable attention due to their privileged potential
activity as androgen antagonists5a and TNF-α inhibitor.5b Moreover, pyromellitic diimide applied
6b
as a high-performance polymeric material for aircraft or spacecraft.6a,
Despite their wide
applicability, the synthesis methods are mainly limited to the dehydrative condensation of either
an phthalic acid,7, 8 or corresponding 1,2-diacids and an amine at high temperature9, 10 and the
cyclization of the amic acid in the presence of acidic catalysts or other promoter (e.g., Lewis acid,
base, dehydrating agent, microwave).8, 10-13 New synthetic methods were reported as well and
selected examples were briefly discussed and listed in scheme 1. For instance, Diels-Alder
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cyclization of styrene with maleimides in the presence of Pd(OAc)2/CuCl and HOAc at 100 oC for
6 h to afford benzo[e]isoindole-1,3-diones derivatives was reported (Scheme 1a).14 Phthalimide
derivatives were obtained by the intermolecular Pd-catalyzed one-pot oxidative carbonylation of
benzaldehyde with primary imines in the presence of CO/O2 (Scheme 1b).15 Alternatively, similar
derivatives could be obtained by the intramolecular ruthenium-catalyzed cyclization/carbonylation
at ortho C-H bonds in aromatic amides (Scheme 1c).16 Moreover, rhodium(III)-catalyzed oxidative
carbonylation of benzamides in the presence of 1 atm of CO also afforded N-substituted
phthalimides (Scheme 1d).17 Last but not least, phenanthro[9,10-c]-1,3-anhydride was used for the
synthesis of benzyldibenzo[e,g]isoindoline-1,3-dione by the reaction with benzylamine in the
presence of AcOH (Scheme 1e).18 In 2007, Cassandra’s group have reported that using
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o
3,4-diarylsubstituted furan-2(5H)-one react with aniline in the presence of p-TsOH at 150 C for
12 h to afford 3,4-diarylsubstituted maleimide in the yield of 34%.19 In general, synthesis of
maleimide derivatives could be summarized in two strategies: (a) the presence of oxidant and/or
catalyst, e.g., Pd, Ru, CuO and Rh; (b) the presence of maleic anhydride and appropriate amine
with the presence of acid or base catalyst.
Scheme 1. Synthetic Approaches to π-Expanded Maleimides
(a) Abbasnia's work
Me
N
Me
O
O
N
Pd(OAc)2, CuCl
HOAc/CH3CN, 100 oC, 6 h
O
O
+
(b) Jiang's work
O
N
1. PdCl2(CH3CN)2, CuO, rt,
toluene/DMF (10:1), 12 h
2. CO/O2 (1:1), 100 oC, 6 h
O
t-BuNH2
+
C
O
(c) Chatani's work
O
O
Ru3(CO)12 (5 mol%), H2O (2 equiv)
CO (10 atm), ethylene (7 atm)
N
N
O
H
N
toluene, 160 oC, 24 h
H
N
(d) Rovis's work
RhCp*(MeCN)3(ClO4)2 (5 mol%)
CO (1atm)
Ag2CO3 (2 equiv), KH2PO4 (2 equiv)
O
O
Me
N
H
N
O
Me
t-AmOH, 100 o
C
(e) Bottle's work
Bn
O
N
O
O
O
O
BnNH2
AcOH, 4 h
(f) This work
R3
N
OH
O
O
O
O
O
O
O
R2
Br
O
DBU, R3NH2
DMF, 120 oC, O2
EtOH, hv
R1
1) CH3CN, Et3N, r.t.
2) DBU, r.t.
Ar, r.t, -H2
R2
R1
R2
R2
R1
R1
2
1
3
R1=H, F, Cl, CN, OMe.
R2=H, CN, Cl, F, OMe, CF3, t-Bu.
R3NH2=Bn, H, i-Pr.
Without any metal catalyst
Available starting materials
π-Expanded syetems
High fluorescence quantum yields
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To the best of our knowledge, directly synthesis of highly conjugated maleimide derivatives
from lactones substrates has not been reported yet. Thus, following our interest in the
photocyclization,20-22 we would like to report a facile stepwise synthesis of π-expanded maleimide
derivatives via a photoinduced dehydrogenative annulation of 3,4-diphenylfuran-2(5H)-ones 1 for
the generation of π-expanded lactones 2, followed by the treatment with primary amines in the
presence of DBU under the O2 atmosphere, which avoid using of any expensive transition metal
catalyst and realize one pot oxidation and ammoniation of 2 to afford maleimides (Scheme 1f).
Table 1. Optimization for the Intramolecular Cyclization of 1a a
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O
O
O
O
solvent
Ar, hv
2a
1a
Yield
(%)b
42
Entry
Concn (mM)
Solvent (v/v)
Time (h)
Conv (%)b
1
2
5
5
5
5
5
3
7
5
5
5
CH2Cl2
MeCN
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5
5
5
5
5
5
3
7
5
51
76
89
93
70
81
60
72
100
83
55
3
Me2CO
EtOH
75
4
78
5
EtOH-H2O (19:1)
EtOH
54
6
63
7
EtOH
45
8
EtOH
65
9
EtOH
70
55c
10
EtOH
a1a was irradiated with a 500 W high-pressure mercury lamp in various solvent (0.2 mmol, 40 mL) at room
temperature under an Ar atmosphere. bIsolated yield. cOpen air atmosphere.
RESULTS AND DISCUSSION
Initially, the solution of 3,4-diphenylfuran-2(5H)-one 1a in dichloromethane (40 mL) was
irradiated with a 500 W high-pressure mercury lamp at room temperature under argon atmosphere
for 5 h to give annulation product 2a in the yield of 42% (Table 1, entry 1). Replacement of
CH2Cl2 with ethanol gave 2a in significantly improved yield (78%) among other solvents, e.g.
acetonitrile and acetone (Table 1, entry 2-4). However, the formation of 2a was dramatically
suppressed with the presence of added water (Table 1, entries 5, 54%). Meanwhile, the substrate
concentration effect was also explored and it is noticed that 2a was obtained in reduced yields
with either higher or lower substrate concentrations (Table 1, entries 6-7, 63% and 45%). Finally,
irradiation time was screened and the yields of 2a were decreased slightly with shortened or
prolonged irradiation (Table 1, entries 8 and 9, 65%-70%). It is important to note that the
cyclization efficiency was also slightly affected under open air condition (Table 1, entries 10,
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55%). As a result, the irradiation of 1a in EtOH at room temperature for 5 h under the argon
5
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atmosphere was determined to be the optimal condition.
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Table 2. Substrate Scope a
O
O
O
O
9
EtOH, hv
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Ar, r.t, 5 h
Ar1
Ar2
Ar1
O
Ar2
2a-2t
1a-1t
O
O
O
O
O
O
O
O
O
OMe
Cl
Cl
2a
2b
2d, 70%
2e
, 72%
, 78%
, 77%
O
2c
, 81%
O
O
O
O
O
O
O
O
O
F
F
F
tBu
CN
MeO
CN
O
2j
, 88%
2i
, 86%
O
2f
2g
2h
, 72%
O
, 78%
O
, 77%
O
O
O
O
O
O
NC
CF3
CF3
CF3
tBu
2n
, 65%
O
2k
2m
2o
, 76%
O
, 89%
, 68%
O
2l
, 87%
O
O
O
O
O
O
O
S
O
O
S
tBu
2p
, 62%
2q,
2r
2s
2t
, 70%
68%
, 51%
, 65%
aAll reactions were carried out on a 0.2 mmol of scale 1 in EtOH (40 mL) and irradiated with a 500 W high-pressure mercury
lamp under the argon atmosphere at room temperature for 5 h.
With the optimal condition in hand, we turned out focus on the scope of functional groups
and the yields were summarized in Table 2. Generally, the substrates containing
electron-withdrawing groups (e.g., CF3, CN), gave better yields comparing to those bearing
electron-donating groups (e.g., Me, OMe). Meanwhile, the halogen atoms, such as F and Cl were
well accommodated and gave lower yields comparing to 2a. Also, substrates with the electron-rich
heteroaromatics, such as thiophene and furan (2q-2t), gave desired products in lower yields.
Under the optimal conditions, 3-(1H-indol-3-yl)-4-phenylfuran-2(5H)-one 1u and
3-phenyl-4-(pyridin-2-yl)furan-2(5H)-one 1v were irradiated. They were failure to annulation and
did not obtain the annulation products. That is to say that the substrates containing nitrogen atom
heteroaromatic ring groups is not dehydrogenative annulation under the irradiation condition.
Table 3. Optimization for the Oxidation and Ammoniation of 2a a
Bn
N
O
O
O
O
Base, BnNH2, O2
DMF, T o
C
2a
3a
Yield
(%)b
29
Entry
Base
Temp (oC)
Time (h)
1
2
Et3N
120
120
4
4
DABCO
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DBU
DBU
DBU
DBU
DBU
DBU
DBU
120
120
100
130
120
120
120
4
4
4
4
2
5
4
54
72
59
70
51
69
25c
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aThe reaction was carried out in DMF under oxygen atmosphere for 4 h. bIsolated yield. cOpen air atmosphere.
Table 4. Synthesis of Maleimide Derivativesa, b
R3
O
N
O
O
O
DBU, R3NH2
DMF, 120 oC, O2
Ar2
Ar1
Ar2
Ar1
2
3
Bn
N
Bn
N
Bn
Bn
Bn
N
Bn
N
N
O
N
O
O
O
O
O
O
O
O
O
O
O
OMe
Cl
Cl
F
3c
3d
, 64%
3a
3b
, 77%
3e
, 66%
, 72%
, 75%
3f
, 74%
Bn
N
Bn
N
Bn
Bn
N
Bn
N
Bn
N
O
O
N
O
O
O
O
O
O
O
O
O
O
NC
F
F
CN
O
MeO
CN
tBu
tBu
CF3
3j
, 75%
3i
3k
, 68%
, 79%
3l
, 72%
3g
, 77%
3h
, 78%
Bn
N
Bn
N
Bn
N
Bn
N
Bn
N
Bn
N
O
O
O
O
O
O
O
O
O
O
O
O
O
CF3
CF3
3r
, 67%
3q
, 64%
3m
3n
3o
, 75%
, 78%
, 81%
3p
, 65%
Bn
Bn
Ph
N
H
N
N
N
N
O
O
O
O
O
O
O
O
O
O
S
S
tBu
3ab
3ac
, 76%
3s
, 59%
, 66%
3aa
, 52%
3t
, 69%
aReaction condition: 2 (0.15 mmol), DBU (0.23 mmol), R3NH2 (0.45 mmol), DMF (2.0 ml), 120 oC, 4 h. bIsolated yield.
It has been reported that treatment of furanone 1a with DBU in acetonitrile under oxygen
atmosphere at ambient temperature gave maleic anhydride in moderate yield.23 Further treatment
of maleic anhydride with aromatic/aliphatic amines in the presence of catalytic Lewis acid
provided maleimide analogues.11 However, there is no report regarding the direct synthesis of
maleimides from lactones 2. Thus, we turned our attention to the synthesis of maleimide
derivatives via the reaction of corresponding lactones 2 with primary amine in the presence of
base and oxygen.
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Initially, 2a was dissolved in DMF, followed with the addition of Et3N and BnNH2. The
resulting solution was heated at 120 °C by oil bath under O2 atmosphere for 4 h. As it is expected,
3a was obtained in 29% yield (Table 3, entry 1). Next, other organic bases, e.g. DABCO and
DBU, were examined (Table 3, entries 2–3) and DBU is turned out to be the best choice, which
gave 3a in 54% (Table 3, entry 3). It indicated that strong base DBU was favor to improve the
yield of 3a. Furthermore, the sequence of reagent addition was investigated as well. After DBU
was added to the solution of 2a in DMF at 120 °C and stirred for 15 minutes, BnNH2 was added to
the the reaction mixture. It is surprised to found that the yield of 3a was boosted to 72 % after the
reaction mixture was stirred for 4 h under O2 atmosphere (Table 3, entry 4). As demonstrated,
both reaction time and temperature have significant effect on the formation of 3a (Table 3, entries
5-8). Open air could also afford the oxidation product, but only 25% of 3a was isolated (Table 3,
entries 9). As a result, it is safe to conclude that cyclization of 2a in the presence of DBU under O2
atmosphere at 120 oC for 4 h is optimal condition.
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Primary amines such as aniline and ammonium hydroxide, isopropylamine were explored
under the optimal conditions. Both aromatic and aliphatic amine could provide the corresponding
products in moderate yields (Table 4). However, reaction of lactons 2 with aniline and ammonium
hydroxide gave the corresponding products 3aa and 3ab in lower yields (52%, 59%), which could
be explained by the reduced electron density on the nitrogen atom. Moreover, the structures of
both lactons 2 and maleimides 3 were characterized by 1H NMR, 13C NMR, 19F NMR, HRMS and
IR. Meanwhile, 1 mmol of scale 1a was carried out in EtOH (200 mL) and irradiated under the
argon atmosphere at room temperature for 5 h. When the reaction was completed, the solvent was
removed and further treatment with BnNH2 in the presence of DBU and O2 provide direct access
to product 3a (205.6 mg, 61 %).
Scheme 2. Proposed Mechanism for the Formation of 3a
O
O
H
O
O
O
O
O
OH
keto form
tautomerization
H
hv
1,5-H
shift
H
H
H
C
1a
A
B
Bn
O
N
O
H
O
O
O
O
O
O
O
enol form
tautomerization
H
O2
DBU
Bn-NH2
-H2
E
D
2a
3a
23-25
On the basis of literature reports18,20-21,
and experimental evidence, a plausible
mechanism for the formation of 3a is depicted in Scheme 2. Irradiation of
3,4-diphenylfuran-2(5H)-one 1a with a high-pressure Hg lamp at ambient temperature generates
intermediate A via an intramolecular 6π-electron cyclization.24 Followed by a thermal suprafacial
[1,5]-H shift25 to give intermediate B. The rearomatization of the benzene ring is the force driving
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for [1,5]-sigmatropic shift. Subsequently, the stable syn-isomer intermediate D was obtained via
the keto-enol isomerization of B. The polar protic solvent EtOH plays a significant role in the
process of keto-enol isomerization, which accounts for higher yield of 2a in EtOH compared to
acetonitrile and acetone. Finally, the annulation product 2a was obtained by hydrogen evolution
via syn-elimination from intermediate D, which share a similar concept with literature reports.20-21
It is important to note that the annulation product 2a was also obtained under the open air (Table
1, entry 10, 55%), it is believed that the photochemical cyclization proceed through the S1 state.20
Meanwhile, the byproduct H2 was successfully detected by GC chromatography during the
annulations of 1m, which proved the solid rationality for the proposed mechanism (Figures S1-2,
please see the Supporting Information). The oxidation of 2a in the presence of DBU gave maleic
anhydride E, which further reacts with benzylamine gave the final product 3a. The reaction
mechanism of 3a has been proved on the basis of previous reports.18, 23
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Lastly, the fluorescence spectra of 3 in CH2Cl2 (10-5 mol/L) was explored, and the
corresponding maxima excitation/emission wavelength and quantum yields were summarized in
Table 5. The presence of heteroaromatics, such as thiophene and furan, benefited the growth of
quantum yields. For instance, 3q-3t (ΦF=0.95, 0.84, 0.70, 0.75) have remarkable fluorescence
properties, and their fluorescence quantum yields are higher than 3a (ΦF=0.58). It is worth noting
that the presence of both electron-donating and electron-withdrawing substituent in the same
substrate, e.g. 3e, 3g, 3j, 3m, gave higher quantum yields (ΦF=0.85, 0.95, 0.80, 0.75) than the one
only bearing electron-withdrawing groups, e.g. 3d, 3f, 3i, 3l (ΦF=0.77, 0.58, 0.29, 0.26).
Furthermore, due to the presence of an extended π-conjugated system and the wavelength of the
lowest energy band for 3p (λem=545 nm) led to red-shifted compared to 3a (λem=462 nm).
Table 5. Spectral Properties of 3 in Dichloromethane Solution (10-5 mol/L)
compounds
λex (nm)
λem (nm)
Stokes shift (cm-1)
ΦF
3a
3b
3c
3d
3e
3f
379
386
396
377
388
374
385
385
377
406
379
373
381
462
467
494
460
469
437
468
468
456
489
462
453
460
4740
4493
5009
4786
4451
3855
4607
4540
4595
4180
4740
4734
4507
0.58
0.88
0.56
0.77
0.85
0.58
0.95
0.84
0.29
0.80
0.89
0.26
0.75
3g
3h
3i
3j
3k
3l
3m
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3n
3o
398
418
375
392
365
382
384
378
372
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495
492
545
465
472
464
474
461
443
458
4923
3598
8319
4005
6211
4626
4944
4763
4309
4762
0.92
0.66
0.19
0.95
0.84
0.70
0.75
0.77
0.52
0.81
3p
3q
3r
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3s
3t
3aa
3ab
3ac
Conclusions
In summary, we have developed a new two-step synthesis of π-expanded maleimide
derivatives. The photoinduced dehydrogenative annulation of 3,4-diphenylfuran-2(5H)-ones 1 in
EtOH under room temperature provided a quick and easy access to π-expanded lactones 2, which
eliminates the use of any transition metal catalyst. Secondly, oxidation of lactones 2 with oxygen
in the presence of DBU gave corresponding anhydride, further treatment with primary amines
provide direct access to maleimide derivatives. Comparing to literature reports, the demonstrated
methodology offers several notable advantages: a) readily available starting materials, b)
π-expanded maleimide and c) no transition metal catalysis required. Additionally, the fluorescent
properties of maleimide derivatives were characterized, which possess high fluorescence quantum
yields in dichloromethane solution.
Experiment Section
General Information. Unless otherwise noted, commercial reagents were purchased from Energy
Chemical. All experiments were determined by thin layer chromatography (TLC). TLC used silica
gel 60 GF254 plate. Column chromatography (200–300 mesh) was performed on silica gel. 1H and
13C NMR spectra were recorded on Bruker 400 or 600 MHzspectrometer. H and 13C NMR
1
spectra were reported in parts per million (ppm) and referenced to the residual solvent peaks
1
[CDCl3 (7.26 ppm) or DMSO-d6 (2.50)] for H NMR and the CDCl3 (77.16 ppm) or DMSO-d6
(39.52) for 13C NMR spectra. High-resolution mass spectra (HRMS) were obtained using the
electron-spray ionization (ESI) technique. Melting points were measured with a X-5
micro-melting point apparatus and were uncorrected. IR spectra were recorded with a Nicollet
170SX FT-IR spectrophotometer with KBr pellets. The fluorescence spectra were measured on a
F-7000 fluorescence spectrometer equipped with a xenon discharge lamp. All the irradiation
experiments were performed in a BL-GHX-V photo-chemical reactor equipped with a 500 W
medium-pressure mercury lamp at room temperature. The emission spectrum of the 500 W
high-pressure mercury lamp was in Supporting Information (Figure S3). The distance from the
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light source to the irradiation vessel was 6 cm. The material of the irradiation vessel was quartz
glass tube and without use of any filters.
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General Procedure A for the Synthesis of 3,4-Diphenylfuran-2(5H)-one (1). To a mixture of
phenylacetic acid (68 mg, 0.5 mmol) and triethylamine (75.8 mg, 0.75 mmol) was dissolved in dry
acetonitrile, phenacyl bromide (108.4 mg, 0.55 mmol) in dry acetonitrile was added dropwise at
room temperature. The resulting mixture was stirred at RT for 6 h, followed by adding
1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) (75.5 mg, 0.5 mmol) and stirred for 30 min. When the
reaction was completed (detected by TLC), water was added and extracted with ethyl acetate (10
mL×3). The combined organic layers were dried over Mg2SO4 and concentrated in vacuo. The
residue was purified by column chromatography on silica (ethyl acetate/petroleum ether, 1:15) to
afford the corresponding products 1a (76.7 mg, 65 %).26 Similarly, compounds 1a-1t were
obtained with the same method as described above.
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General Procedure B for the Synthesis of Phenanthro[9,10-c]furan-1(3H)-one (2). Substrate
3,4-diphenylfuran-2(5H)-one 1a (47.2 mg, 0.2 mmol) was dissolved in EtOH (40 mL) at room
temperature in a quartz tube. The solution was deaerated for 30 min by bubbling argon and
o
irradiated with a high pressure mercury lamp (500 W) at 25 C for 5 h. When the reaction was
completed (detected by TLC), the solvent was removed under reduced pressure. The residue was
purified by column chromatographied on silica (ethyl acetate/petroleum ether, 1:25) to give 2a
(36.5 mg, 78 %). Similarly, compounds 2a-2t were obtained with the same method as described
above.
General Procedure C for the Synthesis of 2-Benzyl-1H-dibenzo[e,g]isoindole-1,3(2H)-dione
(3). A 25 mL round-bottomed flask was charged with phenanthro[9,10-c]furan-1(3H)-one 2a (35.4
mg, 0.15 mmol) in DMF. The flask was sealed and degassed with oxygen five times, DBU (33.9
mg, 0.23 mmol) was added to the solution at 120 °C by oil bath and stirred for 15 minutes,
followed by adding benzylamine (48.2 mg, 0.45 mmol). The reaction mixture was stirred for 4 h in
the presence of atmospheric oxygen. When the reaction was monitored by TLC to achieve full
conversion, water was added and extracted with ethyl acetate (10 mL×3). The combined organic
layers were dried over Na2SO4 and concentrated in vacuo. The residue was purified by column
chromatography on silica (ethyl acetate/petroleum ether, 1:20) to afford the corresponding
products 3a (36.4 mg, 72 %). Similarly, compounds 3a-3t, 3aa-3ac were obtained with the same
method as described above.
Synthesis of 1 mmol scale 3a. Substrate 1a (236 mg, 1 mmol) was dissolved in a solution of
EtOH (200 mL) at ambient temperature in a quartz tube. The solution was deaerated for 30 min by
bubbling argon and irradiated with a high pressure mercury lamp (500 W) at 25 oC for 5 h. When
the reaction was completed (detected by TLC), the solvent was removed under reduced pressure
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and followed by dissolved in DMF. The flask was sealed and degassed with oxygen five times,
DBU (226.5 mg, 1.5 mmol) was added to the solution at 120 °C and stirred for 15 minutes,
followed by adding benzylamine (481.5 mg, 3 mmol). The reaction mixture was stirred for 4 h in
the presence of atmospheric oxygen. When the reaction was monitored by TLC to achieve full
conversion, water was added and extracted with ethyl acetate (30 mL×3). The combined organic
layers were dried over Na2SO4 and concentrated in vacuo. The residue was purified by column
chromatography on silica (ethyl acetate/petroleum ether, 1:20) to afford the corresponding
products 3a (205.6 mg, 61 %).
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Detection of H2. Using argon as carrier gas, stainless steel column (column length 2 m, column
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temperature at 40 C, Tam TDS-01 60~80 mesh) and thermal conductivity detector (TCD
temperature was 120 oC) were used for gas chromatography analysis. Under the conditions of gas
velocity of 0.06 Mpa and the flow rate of 60 mL/min, gas was analyzed at room temperature with
injection of 30 uL.
The chromatographic ethanol (150 mL) was degassed for an hour by ultrasonic. In order to
remove the solvent deoxidization, sodium sulfite (17 g) and hydroquinone (1.5 g) were added and
the mixture was refluxed for 4 h. Then, compound of 1m (63.2 mg, 0.2 mmol) was dissolved in 40
mL deoxidization chromatographic ethanol at room temperature in a quartz tube I. In the same
conditions, quartz tube II without compound 1m was prepared. All operations above were
conducted in argon atmosphere. After strict sealing, tube I and II were irradiated with a
high-pressure mercury lamp (500 W) for 5 hours.
By the GC analysis, the reference substance H2 retention time tR1 was 1.099 min (Figure S1); the
retention time tR2 in the quartz tube I was 1.081 min (Figure S2); the quartz tube II was not found
H2.
3,4-Diphenylfuran-2(5H)-one (1a).26 Yield: 49%, 76.7 mg. 1H NMR (600 MHz, CDCl3) δ (ppm)
7.44-7.3 (m, 10H), 5.18 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 173.5, 156.2, 131.0,
130.7, 130.3, 129.4, 129.1, 128.9, 128.8, 127.6, 126.3, 70.7.
4-Phenyl-3-(p-tolyl)furan-2(5H)-one (1b).27 Yield: 52%, 65.0 mg. 1H NMR (600 MHz, CDCl3) δ
(ppm) 7.39 (dd, J = 5.8, 2.8 Hz, 1H), 7.37 -7.30 (m, 6H), 7.18 (d, J = 7.9 Hz, 2H), 5.16 (s, 2H),
2.37 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 173.7, 155.5, 138.9, 131.2, 130.6, 129.6,
129.3, 129.1, 127.6, 127.3, 126.3, 70.7, 21.5.
1
3-(4-Methoxyphenyl)-4-phenylfuran-2(5H)-one (1c).27 Yield: 56%, 74.5 mg. H NMR (600
MHz, CDCl3) δ (ppm) 7.31 (d, J = 8.4 Hz, 1H), 7.26 (d, J = 4.4 Hz, 2H), 6.82 (d, J = 8.5 Hz, 2H),
5.05 (s, 1H), 3.74 (s, 1H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 173.8, 160.0, 154.9, 131.2,
130.7, 130.5, 129.1, 127.5, 125.7, 122.4, 114.2, 70.6, 55.3.
3-(4-Chlorophenyl)-4-phenylfuran-2(5H)-one (1d).27 Yield: 44%, 59.4 mg. 1H NMR (600 MHz,
CDCl3) δ (ppm) 7.43 (t, J = 7.3 Hz, 1H), 7.40-7.32 (m, 6H), 7.33-7.29 (m, 2H), 5.17 (s, 2H);
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13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 173.2, 156.8, 135.03, 131.0, 130.8, 130.7, 129.3,
129.1, 128.7, 127.6, 125.2, 70.8.
4-(4-Chlorophenyl)-3-(p-tolyl)furan-2(5H)-one (1e). Yellow solid. Yield: 51%, 72.4 mg. Mp:
123.7-125.1 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.33-7.26 (m, 6H), 7.19 (d, J = 7.9 Hz, 2H),
5.13 (s, 2H), 2.38 (s,3H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 173.4, 154.0, 139.3, 136.7,
129.7, 129.6, 129.5, 129.2, 128.9, 127.0, 126.9, 70.4, 21.5; IR (KBr), ν (cm-1) 2920, 1757, 1637,
1442, 1342, 1151, 1036, 823, 513; HRMS (ESI) m/z: calcd for C17H14ClO2 [M + H]+ 285.0677;
found 285.0680.
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3-(4-Fluorophenyl)-4-phenylfuran-2(5H)-one (1f).28 Yield: 40%, 50.8 mg. 1H NMR (600 MHz,
CDCl3) δ (ppm) 7.45-7.39 (m, 3H), 7.36 (t, J = 7.5 Hz, 2H), 7.31 (d, J = 7.5 Hz, 2H), 7.06 (t, J =
1
8.6 Hz, 2H), 5.16 (s, 2H); 13C{1H} (150 MHz, CDCl3) δ (ppm) 173.4, 163.0 (d, J=247.82 Hz),
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156.4, 131.3 (d, J=8.05 Hz), 130.8, 129.2, 127.5, 126.2 (d, J=3.41 Hz), 125.2, 115.9 (d,
2J=21.58 Hz), 70.7.
1
3-(4-Fluorophenyl)-4-(p-tolyl)furan-2(5H)-one (1g).28 Yield: 49%, 65.7 mg. H NMR (600
MHz, CDCl3) δ (ppm) 7.44-7.41 (m, 2H), 7.20 (d, J = 8.2 Hz, 2H), 7.16 (d, J = 8.2 Hz, 2H), 7.07
(t, J = 8.7 Hz, 2H), 5.15 (s, 2H), 2.37 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 173.6,
1
3
163.0 (d, J=247.30 Hz), 156.4, 141.5, 131.4 (d, J=8.17 Hz), 129.9, 127.9, 127.5, 126.5 (d,
4J=3.19 Hz), 124.5, 115.9 (d, 2J=21.22 Hz), 70.7, 21.6.
3-(4-(Tert-butyl)phenyl)-4-(4-fluorophenyl)furan-2(5H)-one (1h). White solid. Yield: 58%,
o
1
89.9 mg. Mp: 135.8-137.1 C. H NMR (600 MHz, CDCl3) δ (ppm) 7.40 (d, J = 8.4 Hz, 2H),
7.36-7.34 (m, 4H), 7.05 (t, J = 8.6 Hz, 2H), 5.14 (s, 2H), 1.33 (s, 9H); 13C{1H} (150 MHz, CDCl3)
1
3
δ (ppm) 173.6, 163.9 (d, J=250.50 Hz), 154.3, 152.2, 129.7 (d, J=7.50 Hz), 129.0, 127.4 (d,
2
4J=3.00 Hz), 127.0, 126.2, 125.9, 116.4 (d, J=22.50 Hz), 70.6, 34.9, 31.4; IR (KBr), ν (cm-1)
2962, 1738, 1603, 1510, 1352, 1234, 1151, 1034, 839, 580; HRMS (ESI) m/z: calcd for
C20H19FO2Na [M + Na]+ 333.1261; found 333.1261.
4-(2-Oxo-4-phenyl-2,5-dihydrofuran-3-yl)benzonitrile (1i). Yellow solid. Yield: 60%, 78.3 mg.
o
1
Mp: 146.1-147.9 C. H NMR (600 MHz, CDCl3) δ (ppm) 7.65 (d, J = 8.4 Hz, 2H), 7.57 (d, J =
8.4 Hz, 2H), 7.45 (t, J = 7.4 Hz, 1H), 7.39 (t, J = 7.7 Hz, 2H), 7.28 (d, J = 7.5 Hz, 2H), 5.20 (s,
2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 172.5, 158.9, 135.0, 132.5, 131.4, 130.2, 130.2,
129.5, 127.6, 124.5, 118.5, 112.6, 70.9; IR (KBr), ν (cm-1) 2941, 1747, 1601, 1441, 1350, 1155,
1070, 949, 847, 694, 548, 490; HRMS (ESI) m/z: calcd for C17H11NO2Na [M + Na]+ 284.0682;
found 284.0684.
4-(4-(4-Methoxyphenyl)-2-oxo-2,5-dihydrofuran-3-yl)benzonitrile (1j). Yellow solid. Yield:
46%, 66.9 mg. Mp: 175.6-176.9 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.68 (d, J = 8.3 Hz, 2H),
7.58 (d, J = 8.3 Hz, 2H), 7.24 (d, J = 8.8 Hz, 2H), 6.88 (d, J = 8.8 Hz, 2H), 5.19 (s, 2H), 3.84 (s,
3H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 172.9, 162.2, 158.2, 135.7, 132.6, 130.3, 129.3,
122.6, 122.4, 118.7, 114.9, 112.5, 70.7, 55.6; IR (KBr), ν (cm-1) 2928, 1755, 1607, 1508, 1394,
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1261, 1173, 1028, 835, 588; HRMS (ESI) m/z: calcd for C18H13NO3Na [M + Na]+ 314.0788;
found 314.0788.
3-(4-(4-(Tert-butyl)phenyl)-5-oxo-2,5-dihydrofuran-3 yl)benzonitrile (1k). White solid. Yield:
45%, 71.3 mg. Mp: 148.2-149.7 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.68 (d, J = 7.7 Hz, 1H),
7.61 (s, 1H), 7.58 (d, J = 8.0 Hz, 1H), 7.49 (t, J = 7.8 Hz, 1H), 7.41 (d, J = 8.4 Hz, 2H), 7.32 (d, J
= 8.4 Hz, 2H), 5.15 (s, 2H), 1.33 (s, 9H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 172.9, 152.9,
152.5, 133.6, 132.7, 131.8, 131.0, 130.1, 128.8, 128.5, 126.1, 126.1, 117.9, 113.7, 70.4, 34.9, 31.3;
IR (KBr), ν (cm-1) 2962, 1751, 1643, 1454, 1342, 1155, 1036, 821, 619, 552; HRMS (ESI) m/z:
calcd for C21H19NO2Na [M + Na]+ 340.1308; found 340.1310.
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4-Phenyl-3-(4-(trifluoromethyl)phenyl)furan-2(5H)-one (1l). Yellow solid. Yield: 63%, 95.8
mg. Mp: 130.8-132.4 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.63 (d, J = 8.1 Hz, 2H), 7.57 (d, J
= 8.1 Hz, 2H), 7.44 (t, J = 7.3 Hz, 1H), 7.38 (t, J = 7.6 Hz, 2H), 7.30 (d, J = 7.5 Hz, 2H), 5.21 (s,
2
2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 173.0, 158.1, 134.0, 131.2, 130.9 (q, J=32.51
3
1
Hz), 130.4, 129.9, 129.4, 127.6, 125.8 (q, J=3.78 Hz), 125.0, 124.0 (q, J=270.97 Hz), 70.9; IR
(KBr), ν (cm-1) 2933, 1742, 1610, 1443, 1331, 1107, 1065, 835, 688, 625, 478; HRMS (ESI) m/z:
calcd for C17H11F3O2Na [M + Na]+ 327.0603; found 327.0606.
4-(P-tolyl)-3-(4-(trifluoromethyl)phenyl)furan-2(5H)-one (1m). White solid. Yield: 60%, 95.4
mg. Mp: 132.1-133.5 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.64 (d, J = 8.2 Hz, 2H), 7.57 (d, J
= 8.2 Hz, 2H), 7.20-7.16 (m, 4H), 5.19 (s, 2H), 2.38 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3) δ
2
3
(ppm) 173.1, 158.1, 141.9, 134.3, 130.8 (q, J=32.50 Hz), 130.1, 129.9, 127.6, 125.8 (q, J=3.78
Hz), 124.1 (q, 1J=270.42 Hz), 123.2, 70.8, 21.6; IR (KBr), ν (cm-1) 2930, 1738, 1639, 1406, 1331,
1115, 1065, 831, 594; HRMS (ESI) m/z: calcd for C18H13F3O2Na [M + Na]+ 341.0760; found
341.0759.
3-(Naphthalen-1-yl)-4-(p-tolyl)furan-2(5H)-one (1n). White solid. Yield: 45%. 67.5 mg. Mp:
156.1-157.9 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.92 (dd, J = 16.1, 8.2 Hz, 2H), 7.66 (d, J =
8.4 Hz, 1H), 7.54 (dd, J = 8.1, 7.2 Hz, 1H), 7.51-7.47 (m, 1H), 7.45 (dd, J = 7.0, 0.9 Hz, 1H),
7.40-7.38 (m, 1H), 7.04 (d, J = 8.3 Hz, 2H), 6.99 (d, J = 8.3 Hz, 2H), 5.41 (q, J = 16.7 Hz, 2H),
2.26 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 174.1, 157.6, 141.7, 134.0, 131.2, 129.8,
129.5, 128.9, 128.8, 128.0, 127.6, 127.4, 126.7, 126.4, 125.8, 125.1, 124.7, 70.7, 21.6; IR (KBr), ν
(cm-1) 2920, 1747, 1641, 1508, 1340, 1192, 1047, 937, 806, 484; HRMS (ESI) m/z: calcd for
C21H16O2Na [M + Na]+ 323.1043; found 323.1040.
4-(Naphthalen-1-yl)-3-(4-(trifluoromethyl)phenyl)furan-2(5H)-one (1o). Yellow solid. Yield:
48%, 84.9 mg. Mp: 113.1-114.8 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.97 (d, J = 8.3 Hz, 1H),
7.92 (d, J = 8.2 Hz, 1H), 7.60 (d, J = 8.3 Hz, 1H), 7.57-7.51 (m, 4H), 7.44-7.41 (m, 2H), 7.39 (d, J
= 8.3 Hz, 2H), 5.18 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 172.3, 159.6, 133.9, 133.2,
2
130.6 (q, J=32.1 Hz), 129.5, 129.2, 129.1, 128.9, 127.6, 127.2, 127.0, 125.9, 125.6, 125.3 (q,
1
3J=3.64 Hz), 124.4, 123.9 (q, J=271.00 Hz), 72.8; IR (KBr), ν (cm-1) 3059, 2930, 1753, 1618,
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1512, 1327, 1119, 1059, 779, 613; HRMS (ESI) m/z: calcd for C21H13F3O2Na [M + Na]+ 377.0760;
found 377.0757.
3,4-Di(naphthalen-1-yl)furan-2(5H)-one (1p). White solid. Yield: 44%, 73.9 mg. Mp:
o
1
201.2-202.6 C. H NMR (600 MHz, CDCl3) δ (ppm) 7.76-7.70 (m, 1H), 7.70-7.55 (m, 5H),
7.34-7.24 (m, 5H), 7.19-7.14 (m, 3H), 5.28 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm)
173.1, 160.9, 133.7, 133.6, 131.3, 130.2, 130.1, 129.5, 129.4, 128.7, 128.6, 128.2, 127.7, 126.9,
126.5, 126.4, 126.2, 126.2, 126.1, 125.2, 125.2, 124.6, 73.2; IR (KBr), ν (cm-1) 3053, 1757, 1649,
1437, 1337, 1153, 1039, 928, 773, 646; HRMS (ESI) m/z: calcd for C24H16O2Na [M + Na]+
359.1043; found 359.1030.
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4-Phenyl-3-(furan-2-yl)furan-2(5H)-one (1q). White solid. Yield: 58%, 65.5 mg. Mp:
o
117.1-118.7 C. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.51 (dd, J = 7.6, 1.8 Hz, 2H), 7.46 (q, J =
5.7 Hz, 3H), 7.38 (s, 1H), 7.22 (d, J = 3.4 Hz, 1H), 6.50 (dd, J = 3.4, 1.8 Hz, 1H), 5.11 (s, 2H);
13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 171.6, 152.7, 145.6, 143.2, 131.4, 130.5, 128.7, 128.1,
116.1, 112.9, 111.7, 71.3; IR (KBr), ν (cm-1) 3138, 1753, 1441, 1340, 1178, 1136, 1013, 870, 746,
692, 586, 496; HRMS (ESI) m/z: calcd for C14H10O3Na [M + Na]+ 249.0522; found 249.0521.
4'-(P-tolyl)-[2,3'-bifuran]-2'(5'H)-one (1r). Yellow solid. Yield: 60%, 72.0 mg. Mp: 132.5-133.8
oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.35-7.32 (m, 3H), 7.20-7.17 (m, 2H), 7.13 (d, J = 3.4
Hz, 1H), 6.43 (dd, J = 3.4, 1.8 Hz, 1H), 5.03 (s, 2H), 2.35 (s, 3H); 13C{1H} NMR (150 MHz,
CDCl3) δ (ppm) 171.8, 153.0, 145.7, 143.0, 141.1, 129.5, 128.4, 128.0, 115.4, 112.7, 111.7, 71.2,
21.7; IR (KBr), ν (cm-1) 2918, 1747, 1624, 1391, 1342, 1180, 1136, 1013, 820, 737, 586, 501;
HRMS (ESI) m/z: calcd for C15H12O3Na [M + Na]+ 263.0679; found 263.0678.
4-Phenyl-3-(thiophen-2-yl)furan-2(5H)-one (1s). Orange solid. Yield: 49%, 59.3 mg. Mp:
o
113.6-115.2 C. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.51 (dd, J = 7.6, 1.8 Hz, 2H), 7.46 (q, J =
5.7 Hz, 3H), 7.38 (s, 1H), 7.22 (d, J = 3.4 Hz, 1H), 6.50 (dd, J = 3.4, 1.8 Hz, 1H), 5.11 (s, 2H);
13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 171.6, 152.7, 145.6, 143.2, 131.4, 130.5, 128.7, 128.1,
116.1, 112.9, 111.7, 71.3; IR (KBr), ν (cm-1) 1749, 1639, 1435, 1041, 702, 604; HRMS (ESI) m/z:
calcd for C14H10SO2Na [M + Na]+ 265.0294; found 265.0295.
3-(4-(Tert-butyl)phenyl)-4-(thiophen-2-yl)furan-2(5H)-one (1t). White solid. Yield: 52%, 77.5
o
mg. Mp: 131.5-132.9 C. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.48-7.47 (m, 2H), 7.43-7.40 (m,
3H), 7.27 (dd, J = 3.8, 0.9 Hz, 1H), 7.05 (dd, J = 5.0, 3.8 Hz, 1H), 5.20 (s, 2H), 1.36 (s, 9H);
13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 173.7, 152.5, 149.3, 133.0, 130.1, 129.2, 128.8, 127.7,
127.0, 125.9, 124.2, 70.1, 34.9, 31.4; IR (KBr), ν (cm-1) 2959, 1742, 1637, 1431, 1340, 1149,
1034, 833, 716, 602; HRMS (ESI) m/z: calcd for C18H18SO2Na [M + Na]+ 321.0920; found
321.0919.
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3-(1H-indol-3-yl)-4-(p-tolyl)furan-2(5H)-one (1u).29 Yellow solid. Yield: 45%, 39.4 mg. H
NMR (600 MHz, CDCl3) δ (ppm) 8.61 (s, 1H), 7.70 (d, J = 2.6 Hz, 1H), 7.41 (d, J = 8.2 Hz, 1H),
7.28 (d, J = 8.2 Hz, 2H), 7.15 (t, J = 7.6 Hz, 1H), 7.09 (d, J = 8.0 Hz, 2H), 6.90 (t, J = 7.5 Hz, 1H),
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6.82 (d, J = 8.0 Hz, 1H), 5.25 (s, 2H), 2.34 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm)
174.9, 152.3, 140.7, 136.3, 129.6, 129.1, 127.6, 126.8, 124.8, 122.5, 121.5, 120.1, 119.3, 111.6,
106.3, 71.0, 21.6.
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3-Phenyl-4-(pyridin-2-yl)furan-2(5H)-one (1v). White solid. Yield: 55%, 65.2 mg. Mp:
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125.1-126.9 C. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.65 (m, 1H), 7.54 (m 1H), 7.47-7.42 (m,
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5H), 7.35 (d, J = 8.0 Hz, 1H), 7.30-7.26 (m, 1H), 5.39 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3)
δ (ppm) 173.8, 155.9, 150.2, 150.2, 136.4, 130.3, 129.4, 129.3, 129.1, 128.6, 124.9, 123.8, 71.2;
IR (KBr), ν (cm-1) 2922, 1747, 1632, 1391, 1030, 696; HRMS (ESI) m/z: calcd for C15H11NO2Na
[M + Na]+ 260.0682; found 260.0681.
Phenanthro[9,10-c]furan-1(3H)-one (2a).30 Yield: 78%, 36.5 mg. 1H NMR (400 MHz, CDCl3) δ
(ppm) 9.10 (d, J = 4.8 Hz, 1H), 8.76 (d, J = 8.3 Hz, 1H), 8.70 (d, J = 4.3 Hz, 1H), 7.88-7.81 (m,
2H), 7.78-7.69 (m, 3H), 5.62 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 171.5, 150.3,
132.4, 130.6, 130.2, 128.3, 128.0, 127.9, 126.0, 125.4, 124.9, 124.1, 123.9, 123.0, 117.5, 68.8.
9-Methylphenanthro[9,10-c]furan-1(3H)-one (2b). White solid. Yield: 77%, 38.2 mg. Mp:
242.6-243.9 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.96 (d, J = 8.2 Hz, 1H), 8.74 (d, J = 8.4 Hz,
1H), 8.47 (s, 1H), 7.82 (dd, J = 14.2, 7.3 Hz, 2H), 7.69 (t, J = 7.4 Hz, 1H), 7.58 (d, J = 8.1 Hz,
1H), 5.60 (s, 2H), 2.65 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 172.1, 147.7, 137.9,
133.0, 130.9, 130.0, 127.6, 125.5, 124.6, 124.3, 124.2, 124.1, 123.0, 119.1, 68.5, 22.4; IR (KBr), ν
(cm-1) 1747, 1637, 1412, 1110, 1040, 754, 604; HRMS (ESI) m/z: calcd for C17H12O2Na [M +
Na]+ 271.0730; found 271.0729.
9-Methoxyphenanthro[9,10-c]furan-1(3H)-one (2c). White solid. Yield: 81%, 42.8mg. Mp:
198.6-200.1 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.88 (d, J = 8.8 Hz, 1H), 8.56 (d, J = 8.3 Hz,
1H), 7.93 (d, J = 2.1 Hz, 1H), 7.77 (t, J = 7.6 Hz, 1H), 7.71 (d, J = 7.7 Hz, 1H), 7.66 (t, J = 7.4 Hz,
1H), 7.30 (dd, J = 8.9, 2.3 Hz, 1H), 5.47 (s, 2H), 4.01 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3) δ
(ppm) 171.9, 159.2, 145.9, 132.3, 132.3, 129.4, 127.6, 125.6, 125.5, 124.1, 123.9, 120.8, 118.8,
117.4, 105.1, 68.3, 55.5; IR (KBr), ν (cm-1) 2934, 1747, 1618, 1450, 1232, 1117, 1024, 835, 758,
609; HRMS (ESI) m/z: calcd for C17H12O3Na [M + Na]+ 287.0679; found 287.0675.
9-Chlorophenanthro[9,10-c]furan-1(3H)-one (2d). White solid. Yield: 70%, 37.5 mg. Mp:
268.2-269.6 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.01 (d, J = 8.6 Hz, 1H), 8.66 (d, J = 8.3 Hz,
1H), 8.62 (d, J = 1.6 Hz, 1H), 7.87 (dd, J = 17.9, 7.6 Hz, 2H), 7.76 (t, J = 7.4 Hz, 1H), 7.69 (dd, J
= 8.6, 1.9 Hz, 1H), 5.62 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 171.6, 148.8, 134.4,
132.2, 132.1, 130.6, 128.9, 128.5, 125.9, 125.8, 125.0, 124.4, 124.2, 123.0, 118.9, 68.5; IR (KBr),
ν (cm-1) 1745, 1636, 1446, 1124, 1020, 754, 588; HRMS (ESI) m/z: calcd for C16H9ClO2Na [M +
Na]+ 291.0183; found 291.0181.
6-Chloro-9-methylphenanthro[9,10-c]furan-1(3H)-one (2e). Yellow solid. Yield: 72%, 40.6
o
mg. Mp: 272.4-273.9 C. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.95 (d, J = 8.2 Hz, 1H), 8.65 (s,
1H), 8.35 (s, 1H), 7.74 (d, J = 8.4 Hz, 1H), 7.67-7.63 (m, 1H), 7.61 (d, J = 8.4 Hz, 1H), 5.58 (s,
2H), 2.65 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 171.7, 147.0, 138.4, 136.4, 134.2,
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130.7, 130.0, 128.2, 125.6, 124.9, 124.2, 124.0, 123.8, 123.0, 119.4, 68.3, 22.4; IR (KBr), ν (cm-1)
2924, 1749, 1636, 1406, 1038, 806, 606; HRMS (ESI) m/z: calcd for C17H11ClO2Na [M + Na]+
305.0340; found 305.0342.
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9-Fluorophenanthro[9,10-c]furan-1(3H)-one (2f). White solid. Yield: 72%, 36.3 mg. Mp:
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215.6-217.1 C. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.12 (dd, J = 8.9, 6.1 Hz, 1H), 8.66 (d, J =
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8.5 Hz, 1H), 8.34-8.31 (m, 1H), 7.89-7.87 (m, 2H), 7.77 (t, J = 7.5 Hz, 1H), 7.53-7.49 (m, 1H),
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132.9 (d, J=8.57 Hz), 132.6 (d, J=4.28 Hz), 130.4, 128.5, 126.9 (d, J=9.00 Hz), 125.9, 124.4,
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124.4, 123.4, 119.0, 117.3 (d, J=23.36 Hz), 108.8 (d, J=22.72 Hz), 68.5; IR (KBr), ν (cm-1)
2170, 1755, 1649, 1406, 1113, 829, 756, 596; HRMS (ESI) m/z: calcd for C16H10FO2 [M + H]+
253.0659, found 253.0647.
9-Fluoro-6-methylphenanthro[9,10-c]furan-1(3H)-one (2g). White solid. Yield: 78%, 41.5 mg.
Mp: 272.2-273.9 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.09 (dd, J = 8.8, 6.1 Hz, 1H), 8.42 (s,
1H), 8.30 (dd, J = 11.0, 2.1 Hz, 1H), 7.76 (d, J = 8.1 Hz, 1H), 7.58 (d, J = 8.0 Hz, 1H), 7.50-7.47
(m, 1H), 5.61 (s, 2H), 2.69 (s, 3H); 13C{1H} NMR (101 MHz, CDCl3) δ (ppm) 171.9, 162.3 (d,
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1J=246.20 Hz), 148.0, 140.9, 132.8 (d, J=4.33 Hz), 132.6 (d, J=8.65 Hz), 130.1, 126.8 (d,
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3J=9.20 Hz), 124.3, 124.2, 123.7, 123.5, 118.1, 117.1 (d, J=23.29 Hz), 108.7 (d, J=22.73 Hz),
68.5, 22.6; IR (KBr), ν (cm-1) 1745, 1610, 1522, 1441, 1173, 1022, 851, 548; HRMS (ESI) m/z:
calcd for C17H11FO2Na [M + Na]+ 289.0635; found 289.0636.
9-(Tert-butyl)-6-fluorophenanthro[9,10-c]furan-1(3H)-one (2h). White solid. Yield: 77%, 47.4
o
mg. Mp: 223.2-224.6 C. 1H NMR (600 MHz, CDCl3, TFA-d1) δ (ppm) 8.86 (d, J = 8.5 Hz, 1H),
8.53 (s, 1H), 8.37 (dd, J = 11.0, 2.2 Hz, 1H), 7.88 (dd, J = 8.5, 1.6 Hz, 1H), 7.82 (dd, J = 8.7, 5.7
Hz, 1H), 7.47-7.44 (m, 1H), 5.65 (s, 2H), 1.52 (s, 9H); 13C{1H} NMR (150 MHz, CDCl3, TFA-d1)
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δ (ppm) 175.3, 164.1 (d, J=250.45 Hz), 151.7, 148.8, 136.2 (d, J=8.79 Hz), 130.1 (d, J=3.81
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Hz), 127.8, 127.0 (d, J=9.46 Hz), 124.3, 124.0, 121.9, 119.2, 117.9, 117.0 (d, J=24.13 Hz),
109.8 (d, 2J=22.79 Hz), 69.9, 35.6, 31.5; IR (KBr), ν (cm-1) 3084, 2961, 1747, 1622, 1419, 1257,
1176, 1022, 845, 584, 469; HRMS (ESI) m/z: calcd for C20H17FO2Na [M + Na]+ 331.1105; found
331.1105.
3-Oxo-1,3-dihydrophenanthro[9,10-c]furan-6-carbonitrile (2i). White solid. Yield: 86%, 44.5
mg. Mp: >300 oC. 1H NMR (600 MHz, CDCl3, TFA-d1) δ (ppm) 9.14 (d, J = 8.4 Hz, 1H), 9.11 (s,
1H), 8.79 (d, J = 8.4 Hz, 1H), 8.03 (t, J = 7.7 Hz, 1H), 8.01-7.95 (m, 2H), 7.89 (t, J = 7.5 Hz, 1H),
5.82 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3, TFA-d1) δ (ppm) 174.5, 153.5, 132.4, 132.3,
130.8, 130.2, 129.7, 129.1, 129.0, 125.5, 125.4, 125.1, 124.3, 118.0, 110.6, 70.3; IR (KBr), ν
(cm-1) 1749, 1622, 1416, 1117, 1038, 847, 756, 617, 530; HRMS (ESI) m/z: calcd for
C17H9NO2Na [M + Na]+ 282.0525; found 282.0531.
9-Methoxy-3-oxo-1,3-dihydrophenanthro[9,10-c]furan-6-carbonitrile (2j). Yellow solid.
Yield: 88%, 50.9 mg. Mp: 261.6-262.9 oC. 1H NMR (400 MHz, CDCl3, TFA-d1) δ (ppm) 9.12 (d,
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J = 8.4 Hz, 1H), 8.99 (s, 1H), 8.07 (s, 1H), 7.96 (d, J = 8.4 Hz, 1H), 7.86 (d, J = 8.8 Hz, 1H), 7.46
(d, J = 8.6 Hz, 1H), 5.74 (s, 2H), 4.14 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3, TFA-d1) δ (ppm)
174.6, 162.8, 153.4, 134.9, 130.2, 130.2, 129.8, 129.1, 126.8, 125.6, 119.8, 119.7, 118.3, 115.6,
110.2, 105.9, 70.0, 56.2; IR (KBr), ν (cm-1) 2926, 2170, 1749, 1616, 1416, 1244, 1063, 1024, 837,
573; HRMS (ESI) m/z: calcd for C18H11NO3Na [M + Na]+ 312.0631; found 312.0628.
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9-(Tert-butyl)-1-oxo-1,3-dihydrophenanthro[9,10-c]furan-5-carbonitrile (2k). White solid.
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Yield: 76%, 47.9 mg. Mp: 230.2-231.8 C. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.05 (d, J = 8.6
Hz, 1H), 8.90 (d, J = 8.6 Hz, 1H), 8.69 (s, 1H), 8.17 (d, J = 1.3 Hz, 1H), 8.03 (dd, J = 8.7, 1.6 Hz,
1H), 7.95 (dd, J = 8.6, 1.7 Hz, 1H), 5.65 (s, 2H), 1.52 (s, 9H); 13C{1H} NMR (150 MHz, CDCl3) δ
(ppm) 171.1, 152.1, 146.5, 135.8, 131.2, 129.8, 129.3, 128.5, 125.5, 125.3, 125.3, 124.4, 121.1,
119.5, 118.3, 111.2, 68.2, 35.7, 31.5; IR (KBr), ν (cm-1) 2963, 1757, 1630, 1392, 1267, 1117,
1036, 841, 636, 473; HRMS (ESI) m/z: calcd for C21H17NO2Na [M + Na]+ 338.1151; found
338.1147.
9-(Trifluoromethyl)phenanthro[9,10-c]furan-1(3H)-one (2l). White solid. Yield: 87%, 52.5
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mg. Mp: 194.6-196.2 C. H NMR (600 MHz, CDCl3) δ (ppm) 9.18 (d, J = 8.4 Hz, 1H), 8.92 (s,
1H), 8.77 (d, J = 8.4 Hz, 1H), 7.95-7.91 (m, 2H), 7.89 (d, J = 7.6 Hz, 1H), 7.80 (t, J = 7.5 Hz, 1H),
5.66 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 171.3, 150.8, 132.8, 131.0, 130.5, 129.8
(q, 2J=31.95 Hz), 128.7, 128.6, 125.7, 125.3, 124.6, 123.6 (q, 1J=273.92 Hz), 124.4, 124.2, 120.5
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(q, J=3.36 Hz), 118.7, 68.5; IR (KBr), ν (cm-1) 2926, 1744, 1632, 1398, 1335, 1111, 1069, 762,
625; HRMS (ESI) m/z: calcd for C17H9F3O2Na [M + Na]+ 325.0447; found 325.0447.
6-Methyl-9-(trifluoromethyl)phenanthro[9,10-c]furan-1(3H)-one (2m). White solid. Yield:
89%, 56.2 mg. Mp: 238.1-239.3 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.12 (d, J = 8.2 Hz, 1H),
8.85 (s, 1H), 8.49 (s, 1H), 7.89 (d, J = 8.2 Hz, 1H), 7.75 (d, J = 7.9 Hz, 1H), 7.60 (d, J = 7.9 Hz,
1H), 5.59 (s, 2H), 2.71 (s, 3H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 171.5, 150.8, 141.7,
132.9, 130.4, 130.1, 129.5 (q, 2J=33.22 Hz), 128.8, 124.5 (q, 1J=271.41 Hz), 125.2, 124.4, 124.2,
124.0, 123.5, 120.4 (q, 3J=3.21 Hz), 117.7, 68.5, 22.6; IR (KBr), ν (cm-1) 2926, 1742, 1626, 1423,
1321, 1115, 1016, 831, 654, 569; HRMS (ESI) m/z: calcd for C18H11F3O2Na [M + Na]+ 339.0603;
found 339.0603.
3-Methylchryseno[5,6-c]furan-11(13H)-one (2n). Yellow solid. Yield: 65%, 38.7 mg. Mp:
231.2-232.6 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.69 (d, J = 8.5 Hz, 1H), 8.66 (d, J = 9.0 Hz,
1H), 8.57 (s, 1H), 8.06 (d, J = 9.0 Hz, 1H), 7.98 (d, J = 7.2 Hz, 1H), 7.79 (d, J = 8.1 Hz, 1H),
7.74-7.71 (m, 1H), 7.70-7.65 (m, 1H), 7.57 (d, J = 7.5 Hz, 1H), 5.70 (s, 2H), 2.70 (s, 3H); 13C{1H}
NMR (150 MHz, CDCl3) δ (ppm) 172.0, 150.0, 141.0, 133.6, 133.3, 130.3, 130.1, 129.6, 129.5,
129.2, 127.8, 127.5, 126.1, 126.1, 124.2, 123.7, 123.4, 120.8, 119.3, 68.0, 22.8; IR (KBr), ν (cm-1)
2964, 1738, 1622, 1416, 1261, 1030, 800, 592, 442; HRMS (ESI) m/z: calcd for C21H15O2 [M +
H]+ 299.1067; found 299.1064.
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3-(Trifluoromethyl)chryseno[5,6-c]furan-13(11H)-one (2o). White solid. Yield: 68%, 47.9 mg.
Mp: >300 oC. 1H NMR (600 MHz, CDCl3, TFA-d1) δ (ppm) 9.17 (d, J = 8.5 Hz, 1H), 8.91 (s, 1H),
8.60 (d, J = 9.1 Hz, 1H), 8.17 (d, J = 9.0 Hz, 1H), 8.11-8.06 (m, 1H), 7.94 (d, J = 8.2 Hz, 1H),
7.88 (d, J = 8.0 Hz, 1H), 7.82-7.76 (m, 2H), 5.86 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3,
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TFA-d1) δ (ppm) 174.5, 149.7, 133.9, 133.0, 132.8, 130.3, 130.3 (q, J=32.13 Hz), 130.1, 123.0,
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129.1, 128.3, 128.0, 124.3 (q, J=270.61 Hz), 124.8 (q, J=3.18 Hz), 123.5, 121.2, 121.2, 121.2,
118.1, 72.9; IR (KBr), ν (cm-1) 3059, 1749, 1626, 1427, 1321, 1119, 1028, 852, 748, 596, 509;
HRMS (ESI) m/z: calcd for C21H12F3O2 [M + H]+ 353.0784; found 353.0797.
Piceno[13,14-c]furan-13(15H)-one (2p). Yellow solid. Yield: 62%, 41.4 mg. Mp: 220.4-221.9
oC. H NMR (600 MHz, CDCl3) δ (ppm) 9.34 (d, J = 8.1 Hz, 1H), 8.75 (d, J = 9.2 Hz, 1H), 8.66
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(d, J = 9.1 Hz, 1H), 8.15 (d, J = 8.8 Hz, 2H), 8.08 (t, J = 7.6 Hz, 2H), 8.01-7.97 (m, 1H), 7.81 (dd,
J = 11.1, 4.0 Hz, 1H), 7.77-7.70 (m, 3H), 6.03 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm)
171.1, 147.4, 133.6, 133.2, 132.9, 131.4, 130.7, 130.6, 130.2, 129.5, 129.5, 128.3, 128.3, 128.0,
127.7, 127.3, 126.8, 125.9, 125.4, 123.8, 122.2, 120.9, 119.9, 71.0; IR (KBr), ν (cm-1) 2922, 1746,
1630, 1392, 1265, 1151, 868, 802, 664; HRMS (ESI) m/z: calcd for C24H14O2Na [M + Na]+
357.0886; found 357.0885.
Naphtho[2,1-b:3,4-c']difuran-10(8H)-one (2q). White solid. Yield: 68%, 30.4 mg. Mp:
218.2-219.9 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.23 (d, J = 8.3 Hz, 1H), 7.89 (d, J = 1.9 Hz,
1H), 7.86 (d, J = 8.3 Hz, 1H), 7.79 (t, J = 7.4 Hz, 1H), 7.63 (t, J = 7.5 Hz, 1H), 7.32 (d, J = 2.0 Hz,
1H), 5.70 (s, 2H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 169.1, 146.1, 145.9, 145.3, 130.8,
129.9, 126.3, 125.2, 124.9, 124.3, 124.1, 111.6, 105.8, 69.9; IR (KBr), ν (cm-1) 2924, 1761, 1630,
1389, 1269, 1123, 1003, 878, 752, 471; HRMS (ESI) m/z: calcd for C14H8O3Na [M + Na]+
247.0366; found 247.0366.
5-Methylnaphtho[2,1-b:3,4-c']difuran-10(8H)-one (2r). White solid. Yield: 51%, 24.2 mg. Mp:
267.2-268.9 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.04 (s, 1H), 7.89 (d, J = 1.8 Hz, 1H), 7.79
(d, J = 8.3 Hz, 1H), 7.48 (d, J = 8.2 Hz, 1H), 7.32 (d, J = 1.9 Hz, 1H), 5.71 (s, 2H), 2.64 (s, 3H);
13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 169.2, 145.7, 145.4, 140.6, 131.2, 128.6, 128.3, 124.7,
124.3, 124.2, 122.2, 110.8, 105.8, 69.9, 22.4; IR (KBr), ν (cm-1) 2924, 2170, 1765, 1657, 1400,
1292, 1105, 760, 548; HRMS (ESI) m/z: calcd for C15H10O3Na [M + Na]+ 261.0522; found
261.0522.
Thieno[2',3':3,4]naphtho[1,2-c]furan-10(8H)-one (2s). White solid. Yield: 65%, 31.2 mg. Mp:
240.4-242.1 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.46 (d, J = 8.2 Hz, 1H), 8.05 (d, J = 5.1 Hz,
1H), 7.89 (d, J = 8.0 Hz, 1H), 7.85-7.72 (m, 2H), 7.67 (t, J = 7.4 Hz, 1H), 5.72 (s, 2H); 13C{1H}
NMR (150 MHz, CDCl3) δ (ppm) 170.5, 146.3, 137.9, 131.2, 130.1, 129.3, 128.7, 126.8, 125.2,
125.1, 124.5, 122.6, 117.6, 70.4; IR (KBr), ν (cm-1) 3113, 1759, 1630, 1396, 1342, 1134, 1030.
727, 609; HRMS (ESI) m/z: calcd for C14H8O2SNa [M + Na]+ 263.0137; found 263.0137.
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5-(Tert-butyl)thieno[2',3':3,4]naphtho[1,2-c]furan-8(10H)-one (2t). White solid. Yield: 70%,
o
41.4 mg. Mp: 251.2-253.1 C. 1H NMR (600 MHz, CDCl3, TFA-d1) δ (ppm) 9.01 (d, J = 8.7 Hz,
1H), 8.34 (d, J = 1.6 Hz, 1H), 8.13 (d, J = 5.3 Hz, 1H), 7.84 (d, J = 5.3 Hz, 1H), 7.81 (dd, J = 8.7,
1.9 Hz, 1H), 5.43 (s, 2H), 1.49 (s, 9H); 13C{1H} NMR (150 MHz, CDCl3) δ (ppm) 171.5, 150.9,
143.4, 141.9, 129.9, 129.7, 129.0, 126.3, 124.8, 124.0, 123.3, 119.6, 117.0, 68.0, 35.4, 31.5; IR
(KBr), ν (cm-1) 2955, 1755, 1512, 1393, 1344, 1178, 1038, 839, 681, 592, 478; HRMS (ESI) m/z:
calcd for C18H16O2SNa [M + Na]+ 319.0763; found 319.0766.
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2-Benzyl-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3a).18 Yield: 72%, 36.4 mg. H NMR (600
MHz, CDCl3) δ (ppm) 9.14 (d, J = 8.1 Hz, 2H), 8.72 (d, J = 8.3 Hz, 2H), 7.81 (t, J = 7.6 Hz, 2H),
7.76 (t, J = 7.5 Hz, 2H), 7.51 (d, J = 7.6 Hz, 2H), 7.35 (t, J = 7.6 Hz, 2H), 7.28 (d, J = 7.2 Hz, 1H),
4.93 (s, 2H)；13C{1H} NMR (151 MHz, CDCl3) δ 169.8, 136.9, 133.6, 129.6, 128.9, 128.7, 128.6,
127.9, 127.7, 126.4, 125.7, 123.3, 41.6.
2-Benzyl-6-methyl-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3b). Yellow solid. Yield: 75%,
39.5 mg. Mp: 241.5-243.2 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.06 (d, J = 7.9 Hz, 1H), 8.96
(d, J = 8.3 Hz, 1H), 8.63 (d, J = 8.2 Hz, 1H), 8.43 (s, 1H), 7.75-7.69 (m, 2H), 7.55 (d, J = 8.3 Hz,
1H), 7.51 (d, J = 7.5 Hz, 2H), 7.35 (t, J = 7.5 Hz, 2H), 7.28 (d, J = 7.3 Hz, 1H), 4.91 (s, 2H), 2.64
(s, 3H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 169.9, 139.9, 137.0, 133.7, 133.1, 130.3,
129.3, 128.9, 128.7, 128.4, 127.9, 127.7, 126.5, 126.3, 126.1, 125.8, 123.6, 123.2, 123.0, 41.6,
22.6; IR (KBr), ν (cm-1) 2930, 1703, 1624, 1392, 1053, 771, 708, 565; HRMS (APCI) m/z: calcd
for C24H18NO2 [M + H]+ 352.1332; found 352.1321.
2-Benzyl-6-methoxy-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3c). Yellow solid. Yield: 77%,
42.4 mg. Mp: 200.5-201.9 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.02 (dd, J = 6.7, 2.6 Hz, 1H),
8.97 (d, J = 9.0 Hz, 1H), 8.52-8.48 (m, 1H), 7.92 (d, J = 2.3 Hz, 1H), 7.71-7.66 (m, 2H), 7.51 (d, J
= 7.3 Hz, 2H), 7.36-7.31 (m, 3H), 7.28 (d, J = 7.3 Hz, 1H), 4.89 (s, 2H), 4.03 (s, 3H); 13C{1H}
NMR (151 MHz, CDCl3) δ (ppm) 169.9, 169.8, 160.7, 137.0, 135.6, 132.4, 128.9, 128.8, 128.7,
128.6, 127.9, 127.9, 127.8, 126.3, 126.1, 124.7, 123.2, 120.2, 118.7, 104.6, 55.6, 41.5; IR (KBr), ν
(cm-1) 2932, 1699, 1610, 1394, 1227, 1055, 770, 627, 494; HRMS (APCI) m/z: calcd for
C24H18NO3 [M + H]+ 368.1281; found 368.1277.
2-Benzyl-6-chloro-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3d). Yellow solid. Yield: 64%,
35.62 mg. Mp: 197.5-199.3 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.07-9.02 (m, 1H), 8.99 (d, J
= 8.7 Hz, 1H), 8.55 (d, J = 1.4 Hz, 1H), 8.50 (d, J = 8.0 Hz, 1H), 7.77-7.71 (m, 2H), 7.65 (dd, J =
8.7, 1.7 Hz, 1H), 7.51 (d, J = 7.5 Hz, 2H), 7.36 (t, J = 7.6 Hz, 2H), 7.29 (t, J = 7.3 Hz, 1H), 4.90 (s,
2H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 169.4, 136.7, 136.2, 134.5, 132.3, 129.8, 129.2,
128.9, 128.8, 128.0, 127.7, 127.6, 127.2, 126.4, 126.0, 123.8, 123.3, 123.1, 41.7; IR (KBr), ν
(cm-1) 2934, 1703, 1607, 1394, 1109, 1013, 766, 465; HRMS (APCI) m/z: calcd for C23H15ClNO2
[M + H]+ 372.0786; found 372.0787.
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2-Benzyl-6-chloro-9-methyl-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3e). Yellow solid. Yield:
66%, 38.1 mg. Mp: 267.2-269.1 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.99 (d, J = 8.7 Hz, 1H),
8.94 (d, J = 8.3 Hz, 1H), 8.56 (d, J = 1.5 Hz, 1H), 8.31 (s, 1H), 7.65 (dd, J = 8.7, 1.8 Hz, 1H), 7.57
(d, J = 8.3 Hz, 1H), 7.50 (d, J = 7.4 Hz, 2H), 7.35 (t, J = 7.6 Hz, 2H), 7.29 (d, J = 7.3 Hz, 1H), 4.90
(s, 2H), 2.64 (s, 3H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 169.5, 140.4, 136.8, 135.9, 134.2,
132.6, 131.0, 129.0, 128.9, 128.8, 128.0, 127.8, 127.7, 126.2, 124.0, 123.9, 123.1, 123.0, 41.6,
22.6; HRMS (APCI) m/z: calcd for C24H17ClNO2 [M + H]+ 386.0942; found 386.0926.
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2-Benzyl-6-fluoro-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3f). Yellow solid. Yield: 74%, 39.4
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mg. Mp: 198.5-200.5 C. H NMR (600 MHz, CDCl3) δ (ppm) 9.10 (dd, J = 9.0, 6.1 Hz, 1H),
9.08-9.05 (m, 1H), 8.49 (d, J = 7.7 Hz, 1H), 8.23 (dd, J = 10.9, 2.0 Hz, 1H), 7.78-7.73 (m, 2H),
7.51 (d, J = 7.5 Hz, 2H), 7.48-7.46 (m, 1H), 7.35 (t, J = 7.5 Hz, 2H), 7.29 (t, J = 7.3 Hz, 1H), 4.91
(s, 2H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 169.5, 169.5, 163.3 (d, 1J=249.81 Hz), 136.8,
135.7 (d, 3J=8.78 Hz), 132.7 (d, 4J=4.51 Hz), 129.6, 129.17, 129.0 (d, 3J=9.01 Hz), 128.9, 128.8,
128.0, 127.4, 126.8 (d, 4J=2.59 Hz), 126.5, 125.9, 123.4, 122.3, 117.9 (d, 2J=23.79 Hz), 108.7 (d,
2J=22.82 Hz), 41.6; 19F NMR (565 MHz, CDCl3) δ -107.4; IR (KBr), ν (cm-1) 2934, 1703, 1609,
1395, 1344, 1192, 1115, 1055, 831, 766, 619, 501; HRMS (APCI) m/z: calcd for C23H15FNO2 [M
+ H]+ 356.1081; found 356.1073.
2-Benzyl-6-fluoro-9-methyl-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3g). Yellow solid. Yield:
77%, 42.6 mg. Mp: 166.3-167.9 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.95 (dd, J = 8.8, 6.3 Hz,
1H), 8.81 (d, J = 8.3 Hz, 1H), 8.09 (s, 1H), 8.04 (d, J = 9.7 Hz, 1H), 7.52 (d, J = 7.7 Hz, 2H), 7.47
(d, J = 8.3 Hz, 1H), 7.38-7.34 (m, 3H), 7.29 (t, J = 7.3 Hz, 1H), 4.87 (s, 2H), 2.59 (s, 3H); 13C{1H}
NMR (151 MHz, CDCl3) δ (ppm) 169.5, 163.0 (d, 1J=249.24 Hz), 139.9, 136.8, 135.0 (d, 3J=8.73
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Hz), 132.7 (d, J=4.20 Hz), 130.8, 128.9, 128.8, 128.7 (d, J=8.88 Hz), 128.0, 126.7 (d, J=2.52
Hz), 126.1, 126.0, 123.6, 123.0, 122.3, 117.6 (d, 2J=23.85 Hz), 108.5 (d, 2J=22.78 Hz), 41.5, 22.5;
19F NMR (376 MHz, CDCl3) δ (ppm) -107.8; IR (KBr), ν (cm-1) 2934, 1703, 1607, 1392, 1165,
1111, 1022, 825, 700, 542, 490; HRMS (APCI) m/z: calcd for C24H17FNO2 [M + H]+ 370.1238;
found 370.1223.
2-Benzyl-6-(tert-butyl)-9-fluoro-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3h). Yellow solid.
Yield: 78%, 48.1 mg. Mp: 183.2-184.9 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.11 (dd, J = 8.9,
6.2 Hz, 1H), 9.02 (d, J = 8.6 Hz, 1H), 8.52 (s, 1H), 8.33-8.30 (m, 1H), 7.87 (d, J = 8.8 Hz, 1H),
7.50-7.46 (m, 3H), 7.34 (t, J = 7.5 Hz, 2H), 7.28 (d, J = 7.3 Hz, 1H), 4.91 (s, 2H), 1.51 (s, 9H);
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126.9, 126.6, 126.1, 123.9, 122.6, 119.1, 117.7 (d, J=23.55 Hz), 108.6 (d, J=22.62 Hz), 41.6,
35.8, 31.4; 19F NMR (376 MHz, CDCl3) δ (ppm) -107.9；IR (KBr), ν (cm-1) 2955, 1703, 1389,
1013, 822, 727, 571, 471; HRMS (APCI) m/z: calcd for C27H23FNO2 [M + H]+ 412.1707; found
412.1706.
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2-Benzyl-1,3-dioxo-2,3-dihydro-1H-dibenzo[e,g]isoindole-6-carbonitrile (3i). Yellow solid.
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Yield: 79%, 42.9 mg. Mp: 265.7-267.5 C. H NMR (600 MHz, CDCl3) δ (ppm) 9.20 (d, J = 8.5
Hz, 1H), 9.14 (d, J = 8.0 Hz, 1H), 8.98 (s, 1H), 8.62 (d, J = 8.3 Hz, 1H), 7.91-7.89 (m, 2H), 7.83
(t, J = 7.5 Hz, 1H), 7.52 (d, J = 7.5 Hz, 2H), 7.36 (t, J = 7.6 Hz, 2H), 7.30 (t, J = 7.3 Hz, 1H), 4.93
(s, 2H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 168.9, 168.9, 136.4, 132.8, 132.7, 130.8,
130.3, 129.8, 129.7, 129.0, 128.8, 128.5, 128.2, 127.7, 127.4, 126.8, 126.5, 125.9, 123.2, 118.8,
112.9, 41.8; IR (KBr), ν (cm-1) 2930, 1707, 1609, 1392, 1117, 1032, 777, 623, 488; HRMS
(APCI) m/z: calcd for C24H15N2O2 [M + H]+ 363.1128; found 363.1128.
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2-Benzyl-9-methoxy-1,3-dioxo-2,3-dihydro-1H-dibenzo[e,g]isoindole-6-carbonitrile
(3j).
Yellow solid. Yield: 75%, 44.1 mg. Mp: 298-299.5 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.18
(d, J = 8.5 Hz, 1H), 9.08 (d, J = 9.0 Hz, 1H), 8.92 (s, 1H), 7.95 (d, J = 2.2 Hz, 1H), 7.89 (dd, J =
8.5, 1.2 Hz, 1H), 7.50 (d, J = 7.4 Hz, 2H), 7.46 (dd, J = 9.0, 2.3 Hz, 1H), 7.35 (t, J = 7.6 Hz, 2H),
7.29 (d, J = 7.3 Hz, 1H), 4.91 (s, 2H), 4.09 (s, 3H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm)
169.2, 169.1, 161.7, 136.5, 135.1, 131.9, 130.7, 129.7, 128.9, 128.8, 128.7, 128.5, 128.4, 128.1,
127.4, 123.5, 120.6, 120.2, 119.0, 112.2, 104.6, 55.9, 41.8; IR (KBr), ν (cm-1) 2928, 1703, 1616,
1393, 1248, 1038, 837, 702, 581, 478; HRMS (APCI) m/z: calcd for C25H17N2O3 [M + H]+
393.1234; found 393.1223.
2-Benzyl-9-(tert-butyl)-1,3-dioxo-2,3-dihydro-1H-dibenzo[e,g]isoindole-5-carbonitrile (3k).
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Yellow solid. Yield: 68%, 42.6 mg. Mp: 240.5-242.2 C. H NMR (600 MHz, CDCl3) δ (ppm)
9.49 (s, 1H), 9.09 (d, J = 8.6 Hz, 1H), 8.82 (d, J = 8.8 Hz, 1H), 8.69 (s, 1H), 7.95 (d, J = 8.6 Hz,
2H), 7.50 (d, J = 7.5 Hz, 2H), 7.35 (t, J = 7.5 Hz, 2H), 7.29 (d, J = 7.3 Hz, 1H), 4.93 (s, 2H), 1.52
(s, 9H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 169.1, 154.0, 136.5, 135.4, 132.6, 131.5, 130.3,
129.3, 128.9, 128.8, 128.1, 126.4, 125.7, 125.3, 124.4, 124.39, 124.3, 119.5, 118.6, 111.9, 41.8,
35.9, 31.4; IR (KBr), ν (cm-1) 2963, 1707, 1624, 1394, 1117, 1036, 841, 700, 633, 490; HRMS
(APCI) m/z: calcd for C28H23N2O2 [M + H]+ 419.1754; found 419.1756.
2-Benzyl-6-(trifluoromethyl)-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3l). White solid. Yield:
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72%, 43.7 mg. Mp: 203.7-205.6 C. 1H NMR (600 MHz, CDCl3) δ (ppm) H NMR (600 MHz,
CDCl3) δ (ppm) 9.12 (d, J = 8.5 Hz, 1H), 9.02 (d, J = 7.9 Hz, 1H), 8.80 (s, 1H), 8.53 (d, J = 8.3 Hz,
1H), 7.87 (d, J = 8.5 Hz, 1H), 7.78-7.72 (m, 2H), 7.53 (d, J = 7.5 Hz, 2H), 7.37 (t, J = 7.6 Hz, 2H),
7.30 (t, J = 7.3 Hz, 1H), 4.91 (s, 2H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 169.0, 169.0,
136.6, 133.2, 132.7, 130.9 (q, 2J=32.42 Hz), 130.3, 129.4, 129.3, 128.9, 128.9, 128.1, 127.2, 124.2
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(q, J=271.06 Hz), 126.6, 125.7, 124.3 (q, J=3.12 Hz), 123.2, 120.5 (q, J=4.02 Hz), 41.8; 19F
NMR (376 MHz, CDCl3) δ (ppm) -62.4; IR (KBr), ν (cm-1) 2934, 1709, 1612, 1393, 1315, 1122,
1022, 843, 700, 613, 509; HRMS (APCI) m/z: calcd for C24H15F3NO2 [M + H]+ 406.1049; found
406.1034.
2-Benzyl-6-methyl-9-(trifluoromethyl)-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3m). Yellow
solid. Yield: 78%, 49.0 mg. Mp: 242.2-243.8 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.06 (d, J =
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8.4 Hz, 1H), 8.88 (d, J = 8.2 Hz, 1H), 8.72 (s, 1H), 8.26 (s, 1H), 7.82 (d, J = 8.4 Hz, 1H), 7.52 (d, J
= 6.6 Hz, 3H), 7.36 (t, J = 7.4 Hz, 2H), 7.30 (t, J = 7.1 Hz, 1H), 4.89 (s, 2H), 2.63 (s, 3H); 13C{1H}
NMR (151 MHz, CDCl3) δ (ppm) 169.1, 169.1, 140.9, 136.6, 133.3, 132.1, 131.1, 130.5 (q,
1
2J=31.89 Hz), 129.5, 128.9, 128.8, 128.1, 127.3, 127.1, 126.2, 125.5, 124.2 (q, J=271.48 Hz),
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124.1 (q, J=2.86 Hz), 123.6, 122.9, 120.4 (q, J=3.96 Hz), 41.7, 22.6; 19F NMR (376 MHz,
CDCl3) δ (ppm) -62.3; IR (KBr), ν (cm-1) 2934, 1705, 1394, 1321, 1117, 1080, 922, 833, 700, 571,
438; HRMS (APCI) m/z: calcd for C25H17F3NO2 [M + H]+ 420.1206; found 420.1209.
12-Benzyl-3-methyl-11H-benzo[e]naphtho[2,1-g]isoindole-11,13(12H)-dione (3n). Yellow
solid. Yield: 81%, 48.7 mg. Mp: 176-177.8 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.45 (d, J =
8.3 Hz, 1H), 9.10 (d, J = 8.4 Hz, 1H), 8.42 (d, J = 9.1 Hz, 1H), 8.30 (s, 1H), 7.93 (d, J = 9.1 Hz,
1H), 7.90 (d, J = 7.5 Hz, 1H), 7.70-7.64 (m, 2H), 7.55 (d, J = 7.5 Hz, 2H), 7.50 (d, J = 8.4 Hz, 1H),
7.35 (t, J = 7.6 Hz, 2H), 7.28 (t, J = 7.4 Hz, 1H), 4.92 (s, 2H), 2.60 (s, 3H); 13C{1H} NMR (151
MHz, CDCl3) δ (ppm) 169.4, 169.3, 140.0, 136.9, 133.7, 133.2, 133.0, 130.6, 130.6, 130.2, 129.1,
128.9, 128.8, 128.6, 127.9, 127.8, 127.8, 127.2, 126.4, 125.9, 125.0, 124.0, 123.1, 120.8, 41.9,
22.7; IR (KBr), ν (cm-1) 2928, 1695, 1392, 1034, 829, 748, 590, 496; HRMS (APCI) m/z: calcd for
C28H20NO2 [M + H]+ 402.1489; found 402.1471.
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12-Benzyl-3-(trifluoromethyl)-11H-benzo[e]naphtho[2,1-g]isoindole-11,13(12H)-dione (3o).
o
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Yellow solid. Yield: 75%, 51.2 mg. Mp: 243.1-245.2 C. H NMR (600 MHz, CDCl3) δ (ppm)
9.46 (d, J = 8.2 Hz, 1H), 9.42 (d, J = 8.6 Hz, 1H), 8.94 (s, 1H), 8.54 (d, J = 9.0 Hz, 1H), 8.08 (d, J
= 9.0 Hz, 1H), 7.95 (dd, J = 15.7, 7.9 Hz, 2H), 7.75-7.70 (m, 2H), 7.55 (d, J = 7.5 Hz, 2H), 7.36 (t,
J = 7.6 Hz, 2H), 7.29 (t, J = 7.3 Hz, 1H), 4.97 (s, 2H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm)
2
172.4, 159.6, 133.9, 133.2, 130.6 (q, J=32.55 Hz), 130.57, 129.5, 129.2, 129.1, 128.9, 127.6,
127.2, 127.0, 123.9 (q, 1J=270.42 Hz), 125.9, 125.6, 125.3 (q, 3J=3.65 Hz), 124.4, 72.8; 19F NMR
(376 MHz, CDCl3) δ (ppm) -62.3; IR (KBr), ν (cm-1) 2951, 1695, 1398, 1311, 1121, 1076, 839,
748, 513; HRMS (APCI) m/z: calcd for C28H17F3NO2 [M + H]+ 456.1206; found 456.1203.
14-Benzyl-13H-dinaphtho[1,2-e:2',1'-g]isoindole-13,15(14H)-dione (3p). Yellow solid. Yield:
65%, 42.6 mg. Mp: 175.6-177.4 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 7.77 (d, J = 7.8 Hz, 2H),
7.73 (d, J = 7.7 Hz, 2H), 7.56 (d, J = 7.3 Hz, 3H), 7.40 (t, J = 7.4 Hz, 2H), 7.37-7.32 (m, 6H), 7.21
(t, J = 7.1 Hz, 2H), 4.95 (s, 2H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 170.5, 140.2, 136.6,
133.6, 130.8, 130.5, 129.1, 128.9, 128.9, 128.5, 128.1, 126.4, 126.2, 125.3, 125.2, 42.6; IR (KBr),
ν (cm-1) 2920, 1701, 1394, 1261, 1101, 1022, 789, 532, 478; HRMS (APCI) m/z: calcd for
C31H20NO2 [M + H]+ 438.1489; found 438.1485.
9-Benzyl-8H-benzo[e]furo[3,2-g]isoindole-8,10(9H)-dione (3q). Yellow solid. Yield: 64%, 31.4
mg. Mp: 193.8-195.5 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.03 (d, J = 8.1 Hz, 1H), 8.13 (d, J
= 8.1 Hz, 1H), 8.02 (d, J = 1.8 Hz, 1H), 7.71-7.65 (m, 2H), 7.51 (d, J = 7.4 Hz, 2H), 7.35-7.33 (m,
3H), 7.28 (d, J = 7.3 Hz, 1H), 4.92 (s, 2H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 169.6,
166.5, 148.8, 144.6, 136.7, 130.8, 130.8, 129.2, 128.8, 128.0, 127.8, 126.2, 125.4, 124.1, 124.1,
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117.8, 106.4, 41.7; IR (KBr), ν (cm-1) 2941, 1701, 1387, 1337, 1057, 1022, 914, 756, 590, 511;
HRMS (APCI) m/z: calcd for C21H14NO3 [M + H]+ 328.0968; found 328.0970.
9-Benzyl-5-methyl-8H-benzo[e]furo[3,2-g]isoindole-8,10(9H)-dione (3r). Yellow solid. Yield:
67%, 34.3 mg. Mp: 241.9-243.8 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 8.81 (d, J = 8.6 Hz, 1H),
7.90 (s, 1H), 7.81 (s, 1H), 7.43 (d, J = 7.5 Hz, 2H), 7.40 (d, J = 8.6 Hz, 1H), 7.26 (t, J = 7.5 Hz,
2H), 7.21-7.17 (m, 2H), 4.83 (s, 2H), 2.52 (s, 3H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm)
169.7, 166.6, 148.5, 144.8, 139.7, 136.8, 131.1, 130.0, 128.8, 128.8, 127.9, 125.8, 124.1, 123.5,
123.3, 116.8, 106.3, 41.6, 22.3; IR (KBr), ν (cm-1) 2932, 1705, 1607, 1387, 1344, 1055, 1024, 827,
741, 617, 447; HRMS (APCI) m/z: calcd for C22H16NO3 [M + H]+ 342.1125; found 342.1128.
9-Benzyl-8H-benzo[e]thieno[3,2-g]isoindole-8,10(9H)-dione (3s). Yellow solid. Yield: 66%,
33.9 mg. Mp: 244.7-246.4 oC. 1H NMR (600 MHz, CDCl3) δ (ppm) 9.01 (d, J = 8.1 Hz, 1H), 8.35
(d, J = 8.0 Hz, 1H), 8.01 (d, J = 5.2 Hz, 1H), 7.92 (d, J = 5.2 Hz, 1H), 7.73-7.67 (m, 2H), 7.52 (d, J
= 7.5 Hz, 2H), 7.35 (t, J = 7.4 Hz, 2H), 7.29 (d, J = 7.3 Hz, 1H), 4.92 (s, 2H); 13C{1H} NMR (151
MHz, CDCl3) δ (ppm) 169.7, 168.3, 142.5, 136.8, 132.9, 132.0, 129.2, 128.9, 128.9, 128.8, 128.1,
128.0, 126.8, 126.0, 125.9, 124.5, 124.1, 122.0, 41.8; IR (KBr), ν (cm-1) 2930, 1701, 1630, 1394,
1342, 1059, 725, 507; HRMS (APCI) m/z: calcd for C21H14NO2S [M + H]+ 344.0740; found
344.0726.
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9-Benzyl-5-(tert-butyl)-8H-benzo[e]thieno[3,2-g]isoindole-8,10(9H)-dione (3t). Yellow solid.
o
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Yield: 69%, 41.3 mg. Mp: 186.5-188.4 C. H NMR (600 MHz, CDCl3) δ (ppm) 8.96 (d, J = 8.8
Hz, 1H), 8.34 (s, 1H), 8.09 (d, J = 5.3 Hz, 1H), 7.93 (d, J = 5.3 Hz, 1H), 7.81 (d, J = 8.6 Hz, 1H),
7.51 (d, J = 7.5 Hz, 2H), 7.34 (t, J = 7.5 Hz, 2H), 7.28 (d, J = 7.4 Hz, 1H), 4.92 (s, 2H), 1.48 (s,
9H); 13C{1H} NMR (151 MHz, CDCl3) δ (ppm) 169.9, 168.5, 152.6, 142.4, 136.8, 132.4, 132.3,
128.9, 128.8, 128.7, 127.9, 127.0, 126.1, 125.7, 124.2, 124.0, 122.0, 119.8, 41.8, 35.6, 31.3; IR
(KBr), ν (cm-1) 2957, 1705, 1622, 1394, 1342, 1015, 825, 696, 563; HRMS (APCI) m/z: calcd for
C25H22NO2S [M + H]+ 400.1366; found 400.1365.
1
2-Phenyl-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3aa).31 Yield: 52%, 25.2 mg. H NMR (600
MHz, CDCl3) δ (ppm) 9.15 (d, J = 8.1 Hz, 2H), 8.72 (d, J = 8.4 Hz, 2H), 7.80 (t, J = 7.5 Hz, 2H),
7.74 (t, J = 7.5 Hz, 2H), 7.51-7.45 (m, 4H), 7.37 (t, J = 6.8 Hz, 1H).
1H-Dibenzo[e,g]isoindole-1,3(2H)-dione (3ab). Yellow solid. Yield: 59%, 21.8 mg. Mp:
221.5-223.1 oC. 1H NMR (600 MHz, DMSO) δ (ppm) 11.35 (s, 1H), 9.03 (dd, J = 7.5, 6.3 Hz, 4H),
7.95-7.91 (m, 2H), 7.90-7.87 (m, 2H); 13C{1H} NMR (151 MHz, CDCl3, TFA-d1) δ (ppm) 172.6,
134.3, 130.6, 129.2, 128.0, 126.2, 125.4, 123.6; IR (KBr), ν (cm-1) 2170, 1657, 1398, 1290, 1082,
849, 540; HRMS (APCI) m/z: calcd for C16H10NO2 [M + H]+ 248.0706; found 248.0710.
2-Isopropyl-1H-dibenzo[e,g]isoindole-1,3(2H)-dione (3ac). Yellow solid. Yield: 76%, 34.5 mg.
o
1
Mp: 212.2-213.9 C. H NMR (600 MHz, CDCl3) δ (ppm) 9.11 (d, J = 7.8 Hz, 2H), 8.65 (d, J =
8.2 Hz, 2H), 7.78-7.71 (m, 4H), 4.61 (m, 1H), 1.58 (d, J = 7.0 Hz, 6H); 13C{1H} NMR (151 MHz,
CDCl3) δ (ppm) 170.1, 133.4, 129.3, 128.4, 127.4, 126.2, 125.7, 123.2, 43.0, 20.5; IR (KBr), ν
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(cm-1) 2970, 2170, 1659, 1394, 1082, 762, 544; HRMS (APCI) m/z: calcd for C19H16NO2 [M +
H]+ 290.1176; found 290.1180.
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ASSOCIATED CONTENT
Supporting Information
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The Supporting Information is available free of charge on the ACS Publications website, and
include NMR spectra, absorption spectra, fluorescence spectra and detection of the generation of
H2 chromatogram (PDF).
AUTHOR INFORMATION
Corresponding Author
* E-mail: zhangzt@snnu.edu.cn
ORCID
Yang Kang: 0000-0003-0856-1008
WeiZhang: 0000-0001-6563-2322
Tao Wang: 0000-0002-1494-5297
Yong Liang: 0000-0002-7225-7062
Zunting Zhang: 0000-0003-0806-2452
Present Address
†Department of Molecular Medicine, Beckman Research Institute of City of Hope, Duarte, CA
91010, US
Notes
The authors declare no competing financial interests.
ACKNOWLEDGMENTS
We are grateful for financial support from the National Natural Science Foundation of China
(Nos: 21672132 and 21502110).
REFERENCES
1. Fagnoni, M.; Dondi, D.; Ravelli, D.; Albini, A. Photocatalysis for the Formation of the C−C
Bond. Chem. Rev. 2007, 107, 2725-2756.
2. Dichiarante, V.; Fagnoni, M.; Albini, A. Eco-friendly hydrodehalogenation of electron-rich aryl
chlorides and fluorides by photochemical reaction. Green Chem. 2009, 11, 942-945.
3. Jørgensen, K. B. Photochemical Oxidative Cyclisation of Stilbenes and Stilbenoids–The
Mallory-Reaction. Molecules. 2010, 15, 4334-4358.
4. Mallory, F. B.; Butler, K. E.; Bérubé, A.; Luzik, E. D.; Mallory, C. W.; Brondyke, E. J.;
Hiremath, R.; Ngo, P.; Carroll, P. J. Phenacenes: a family of graphite ribbons. Part 3: Iterative
strategies for the synthesis of large phenacenes. Tetrahedron. 2001, 57, 3715-3724.
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Page 24 of 25
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8
9
5. (a) Miyachi, H.; Azuma, A.; Kitamoto, T.; Hayashi, K.; Kato, S.; Koga, M.; Sato, B.;
Hashimoto, Y. Potent novel nonsteroidal androgen antagonists with a phthalimide skeleton.
Bioorg. Med. Chem. Lett. 1997, 7, 1483-1488; (b) Miyachi, H.; Azuma, A.; Hioki, E.; Iwasaki, S.;
Kobayashi, Y.; Hashimoto, Y. Inducer-Specific Bidirectional Regulation by Thalidomide and
Phenylphthalimides of Tumor Necrosis Factor-α Production. Biochem. Biophys. Res. Comm. 1996,
224, 426-430.
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
6. (a) Chae, K. H.; Kim, Y. H. Red–Yellow Fluorescence Patterning of a Polymer Film Containing
Phthalimido Carbamate Groups. Adv.Funct. Mater. 2007, 17, 3470-3476; (b) Chen, G.; Zhang, X.;
Zhang, S.; Chen, T.; Wu, Y. Synthesis, properties, and gas permeation performance of cardo
poly(arylene ether sulfone)s containing phthalimide side groups. J. Appl. Polym. Sci. 2007, 106,
2808-2816.
7. Fraga-Dubreuil, J.; Çomak, G.; Taylor, A. W.; Poliakoff, M. Rapid and clean synthesis of
phthalimide derivatives in high-temperature, high-pressure H2O/EtOH mixtures. Green Chem.
2007, 9, 1067-1072.
8. Martin, B.; Sekljic, H.; Chassaing, C. Microwave-Assisted Solid-Phase Synthesis of
Phthalimides. Org. Lett. 2003, 5, 1851-1853.
9. Da Settimo, A.; Primofiore, G.; Da Settimo, F.; Simorini, F.; La Motta, C.; Martinelli, A.;
Boldrini, E. Synthesis of pyrrolo[3,4-c]pyridine derivatives possessing an acid group and their in
vitro and in vivo evaluation as aldose reductase inhibitors. Eur. J. Med. Chem. 1996, 31, 49-58.
10. Mehta, N. B.; Phillips, A. P.; Lui, F. F.; Brooks, R. E. Maleamic and Citraconamic Acids,
Methyl Esters, and Imides. J. Org. Chem. 1960, 25, 1012-1015.
11. Ali, M. A.; Moromi, S. K.; Touchy, A. S.; Shimizu, K.-i. Direct Synthesis of Cyclic Imides
from Carboxylic Anhydrides and Amines by Nb2O5 as a Water-Tolerant Lewis Acid Catalyst.
ChemCatChem. 2016, 8, 891-894.
12. Abdel-Aziz, A. A. M. Novel and versatile methodology for synthesis of cyclic imides and
evaluation of their cytotoxic, DNA binding, apoptotic inducing activities and molecular modeling
study. Eur. J. Med. Chem. 2007, 42, 614-626.
13. Upadhyay, S. K.; Pingali, S. R. K.; Jursic, B. S. Comparison of microwave-assisted and
conventional preparations of cyclic imides. Tetrahedron Letters. 2010, 51, 2215-2217.
14. Sheykhan, M.; Shafiee-Pour, M.; Abbasnia, M. C–H Activation under the Guise of
Diels–Alder Reaction: Annulation toward the Synthesis of Benzo[e]isoindole-1,3-diones. Org.
Lett. 2017, 19, 1270-1273.
15. Ji, F.; Li, J.; Li, X.; Guo, W.; Wu, W.; Jiang, H. Carbonylation Access to Phthalimides Using
Self-Sufficient Directing Group and Nucleophile. J. Org. Chem. 2018, 83, 104-112.
16. Inoue, S.; Shiota, H.; Fukumoto, Y.; Chatani, N. Ruthenium-Catalyzed Carbonylation at Ortho
C−H Bonds in Aromatic Amides Leading to Phthalimides: C−H Bond Activation Utilizing a
Bidentate System. J. Am. Chem. Soc. 2009, 131, 6898-6899.
17. Du, Y.; Hyster, T. K.; Rovis, T. Rhodium(III)-catalyzed oxidative carbonylation of
benzamides with carbon monoxide. Chem. Commun. 2011, 47, 12074-12076.
18. Blinco, J. P.; Fairfull-Smith, K. E.; Micallef, A. S.; Bottle*, S. E. Highly efficient,
stoichiometric radical exchange reactions using isoindoline profluorescent nitroxides. Polym.
Chem. 2010, 1, 1009-1012.
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Page 25 of 25
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1
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5
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7
8
9
19. Fukumoto, S.; Matsunaga, N.; Ohra, T.; Ohyabu, N.; Hasui, T.; Motoyaji, T.; Siedem, C. S.;
Tang, T. P.; Demeese, L. A.; Gauthier, C. Preparation of Fused Heterocycles as Mineralocorticoid
Receptor Antagonists. WO2007077961 A2, Jul 12, 2007.
20. Han, J.; Wang, T.; Liang, Y.; Li, Y.; Li, C.; Wang, R.; Feng, S.; Zhang, Z.
Transition-Metal-Free
Photoinduced
Intramolecular
Annulation
of
10
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47
48
49
50
51
52
53
54
55
56
57
58
59
60
2,3-Di(hetero)arylchromen-4-one. Org. Lett. 2017, 19, 3552-3555.
21. Kang, Y.; Wang, T.; Liang, Y.; Zhang, Y.; Wang, R.; Zhang, Z. Annulation of
2,3-diphenyl-4H-chromen-4-ones via photo-induced hydrogen evolution. RSC Adv. 2017, 7,
44333-44339.
22. Shi, J.; Kang, Y.; Wang, T.; Liang, Y.; Zhang, Z. Synthesis of Polycyclic Heteroaromatic
Coumarins via Photoinduced Dehydrogenative Annulation of 4-Phenyl-3-heteroarylcoumarins. J.
Org. Chem. 2018, 83, 13940-13948.
23. Pattabiraman, V. R.; Padakanti, S.; Veeramaneni, V. R.; Pal, M.; Yeleswarapu, K. R.
Synthesis of 3,4-Diarylsubstituted Maleic Anhydride/Maleimide via Unusual Oxidative
Cyclization of Phenacyl Ester/Amide. Synlett. 2002, 2002, 0947-0951.
24. Irie, M.; Fukaminato, T.; Matsuda, K.; Kobatake, S. Photochromism of Diarylethene
Molecules and Crystals: Memories, Switches, and Actuators. Chem. Rev. 2014, 114,
12174-12277.
25. Hoffmann, R.; Woodward, R. B. Conservation of orbital symmetry. Acc. Chem. Res. 1968, 1,
17-22.
26. Yamakawa, N.; Suzuki, K.; Yamashita, Y.; Katsu, T.; Hanaya, K.; Shoji, M.; Sugai, T.;
Mizushima, T. Structure–activity relationship of celecoxib and rofecoxib for the membrane
permeabilizing activity. Bioorg. Med. Chem., 2014, 22, 2529-2534.
27. Uddin, M. J.; Rao, P. N. P.; Knaus, E. E. Design and synthesis of novel rofecoxib analogs as
potential cyclooxygenase (COX-2) inhibitors: Replacement of the methylsulfonyl pharmacophore
by a sulfonylazide bioisostere. J. Heterocycl. Chem., 2003, 40, 861-868.
28. Uddin, M. J.; Elleman, A. V.; Ghebreselasie, K.; Daniel, C. K.; Crews, B. C.; Nance, K. D.;
Huda, T. Design of Fluorine-Containing 3,4-Diarylfuran-2(5H)-ones as Selective COX-1
Inhibitors. ACS Med. Chem. Lett., 2014, 5, 1254-1258.
29. Horký, P.; Voráčová, M.; Konečná, K.; Sedlák, D.; Bartůněk, P.; Vacek, J.; Kuneš, J.; Pour,
M. Nontoxic combretafuranone analogues with high in vitro antibacterial activity. Eur. J. Med.
Chem., 2018, 143, 843-853.
30. Saha, M.; Das, T. K.; Das, A.; Ghosh, N. R. Synthetic Studies with a Bisdiazoketone.
Synthetic Commun., 1990, 20, 137-151.
31.
Grycz,
P.;
Gawroński,
J.
IMPROVED
SYNTHESIS
OF
cis-9,10-DIHYDRO-9,10,-PHENANTHRENEDICARBOXIMIDES
AND
9,10-PHENANTHRENEDICARBOXIMIDES. Org. Prep. Proced. Int., 1999, 31, 442-447.
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