Three-Component Ordered Annulation of Amines, Ketones, and Nitrovinylarenes: Access to Fused Pyrroles and Substituted Indoles under Metal-Free Conditions

Article abstract of DOI:10.1021/acs.joc.8b02410

An efficient synthesis of pyrroles and indoles has been developed via three-component ordered annulation of amines, ketones, and nitrovinylarenes. The reaction selectivity can be well controlled under metal-free conditions to afford the corresponding heterocyclic products in good yields.

Full text of DOI:10.1021/acs.joc.8b02410

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Article
Three-Component Ordered Annulation of Amines,
Ketones and Nitrovinylarenes: Access to Fused Pyrroles
and Substituted Indoles under Metal-Free Conditions
Jinjin Chen, Dan Chang, Fuhong Xiao, and Guo-Jun Deng
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.8b02410 • Publication Date (Web): 27 Dec 2018
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Three-Component Ordered Annulation of Amines, Ketones and
Nitrovinylarenes: Access to Fused Pyrroles and Substituted Indoles
under Metal-Free Conditions
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Jinjin Chen, Dan Chang, Fuhong Xiao*, and Guo-Jun Deng*
Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory
of Environmentally Friendly Chemistry and Application of Ministry of Education, College of
Chemistry, Xiangtan University, Xiangtan 411105, China
Fax: (+86)-731-58292251
R3
R3
NO2
R3
1) toluene, Ar
150 oC, 2 h
toluene, Ar
150 oC, 2 h
R4
+
R1
R4
R1
R4
(d)
O
N
R2
N
R2
( )n
( )n
2) I2 (25 mol%)
NH2
R2
R1
DMSO (2.0 eq.)
150 oC, O2, 3 h
n=1, 2, 3, 7
n=1
( )n
50 examples
10 examples
up to 93% yield
up to 75% yield
ABSTRACT: An efficient synthesis of pyrroles and indoles has been developed via
three-component ordered annulation of amines, ketones and nitrovinylarenes. The reaction
selectivity can be well controlled under metal-free conditions to afford the corresponding
heterocyclic products in good yields.
■ INTRODUCTION
Pyrroles and indoles both are privileged nitrogen-containing heterocycles and frequently
found in biologically active natural products and pharmaceuticals. Some of them have antifungal,
antitumor, anticancer, antibacterial, antiplasmodium, and anti-inflammortory properties.1
Furthermore, pyrroles and indoles can be used as important building blocks in the synthesis of
other nitrogen-containing biologically active chemicals and functional materials.2 Accordingly, the
development of efficient methods for the construction of pyrroles and indoles has attracted
considerable interest and great progress has been made during the past several decades.3
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Cyclohexanones have received much attention because of the advantages of low-cost, stability
and commercially available. In the past decade, cyclohexanones have been emerging as
environmentally friendly and key reagents in organic synthesis. The versatility of cyclohexanones
as aryl sources is reflected by the broad range of functionalized aromatic products they now
provide, which includding phenols,4 aromatic amines,5 aromatic ethers,6 biarenes,7 and some kinds
of benzoheterocycle.8 Besides, cyclohexanones have been proved to be versatile building blocks
for the construction of heterocycles without further dehydrogenative aromatization process. Our
recent research revealed that cyclohexanones can couple with amines to permit
1,2-difunctionalization/C-N bond formation under sulfur-based aerobic conditions.9 (Scheme 1a-b).
In 2016, we developed a highly efficient method for carbazole formation through three-component
assembly of indoles, ketones, and nitroalkenes under metal-free conditions (Scheme 1c).10
However, cyclohexanone acts as the six-membered ring and dehydrogenative aromatization did not
occur in these systems.
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Scheme 1 Cyclohexanone involves heterocyclic compounds formation
Previous work (cyclohexanone as six-membered ring)
O
S
N
S
N
S8
+
+
NH2
N
(a)
(b)
N
O
S8 + KHCO3
R
2
R
NH2
N
R=Ar, alkyl
R
O
NO2
R2
NH4I
+
+
(c)
N
R1
R2
R3
N
R1
R3
This work (cyclohexanone as both six-membered ring and aryl source)
R3
R3
NO2
R3
O
1) toluene, Ar
150 oC, 2 h
toluene, Ar
R4
150 oC, 2 h
R4
+
R1
R1
R4
(d)
N
N
R2
( )n
( )n
2) I2 (25 mol%)
DMSO (2.0 eq.)
150 oC, O2, 3 h
R2
n=1, 2, 3, 7
50 examples
up to 93% yield
NH2
R2
R1
n=1
10 examples
up to 75% yield
( )n
Metal-free
One-pot !
！
As we know, enamines are important precursors for pyrrole synthesis. However, these
important precursors are mainly rely on addition reaction of amines with alkynes which
means aditional isolation process is usually required. The multicomponent reactions (MCRs)
have been proved to be powerful protocol for the synthesis of pyrrole derivatives using simple
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and readily available substrates.11 Many MCRs pyrrole synthesis methods involve an enamine
intermediate in situ generated from amines and alkynes or carbonyl compounds have been
developed. The resulted enamines or enamides could subsequently cyclize with other
substrates such as alkenes,12 ketones,13 aldehydes,14 diketoesters15 and diols16. In 2013,
Davies and coworkers developed a strategy to convert cyclic ketones to 2,3-fused pyrroles via
multi-step procedure. However, functionalized cyclohexenyl derivatives and Rh/Cu catalysts
are required for the one-pot 2,3-fused pyrrole and substituted indole synthesis.17 Other
methods to convert fused pyrroles (tetrahydroindoles) into substituted indoles via
dehydrogenation process usually use Pd/C or Pd/Al2O3 as catalyst at high temperatures.18
Although these metal-catalyzed methods are very useful for the synthesis of pyrrole and
indoles, critical issues remain regarding the presence of metal impurities in the final product,
which may restrict their practical application. Therefore, efficient procedures for these
nitrogen-containing heterocycles using readily available starting materials under metal-free
conditions are still highly desirable. Although some efficient metal-free methods have been
recently developed,19 efficient method for both pyrrole and indole synthesis using the same
starting materials is rare. As our continuing efforts on heterocycle formation under metal-free
conditions,20 herein we describe a general three-component reaction for fused pyrroles
synthesis from readily available cyclic ketones, amines and nitrovinylarenes. Futhermore,
substituted indoles could be obtained from the same starting materials when the reaction was
carried out under oxidative conditions without the aid of metal-catalyst (Scheme 1d).
■ RESULTS AND DISCUSSION
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Our study was initiated by using cyclohexanone (1a), aniline (2a) and
(E)-(2-nitrovinyl)-benzene (3a) as the model reaction under an argon atmosphere to optimize
the reaction conditions (Table 1). When the mixture in PhCl without any initiator was stirred
at 150°C for 2 h, the desired product 4a was obtained in 68% yield (entry 1). Encouraged by
this result, various organic solvents were screened to find the suitable solvent (entries 2-7).
To our delight, toluene showed the best efficiency to provide 4a in 95% yield (entry 3). Other
organic solvents such as mesitylene, DMSO, NMP and 1,1,2,2-tetrachloroethane were less
effective (entries 4-7). Decreasing the amount of 2a or the reaction temperature both did not
enhance the reaction yields (entries 8 and 9). It should be noted that lower yield was obtained
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when the reaction was run under air atmosphere (entry 10). Decreasing the amount of
cyclohexanone and aniline decreased the reaction yield (entry 11). When three equiv. of 1a
and 2a were used, the yield was not improved obviously (entry 12).
9
Table 1. Optimization of the reaction conditionsa
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Ph
O
NH2
NO2
+
+
Ph
N
Ph
1a
2a
3a
4a
yieldb(%)
entry
1
solvent
PhCl
68
85
2
o-xylene
toluene
mesitylene
DMSO
NMP
3
95
4
57
5
trace
60
6
7
CHCl2CHCl2
toluene
42
8c
9d
10e
11f
12g
75
toluene
80
toluene
85
toluene
51
toluene
96
a
o
Conditions: 1a (0.4 mmol), 2a (0.4 mmol), 3a (0.2 mmol), solvent (0.5 mL), 150 C, 2 h, under argon
b
c
d
o
e
f
g
unless otherwise noted. GC yield. 2a (0.3 mmol). 140 C. under air. 1a (0.2 mmol), 2a (0.2 mmol).
1a (0.6 mmol), 2a (0.6 mmol).
Besides (E)-(2-nitrovinyl)-benzene, several other alkenes were also investigated to
provide two-carbon source for the present three-component reaction (Scheme 2). However, all
of them were found to be unfruitful for the pyrrole formation. These results show the unique
feature of nitrovinylarenes in this reaction system.
Scheme 2. Screening Different Alkenes for the Pyrrole Formationa
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R
O
NH2
LG
+
+
R
toluene, Ar
150 oC, 2 h
N
Ph
4a
(R=Ph)
1a
2a
NO2
3
Br
COOH
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80%
0%
O
trace
0%
HO
SO2Ph
O
O
0%
0%
a Conditions: 1a (0.4 mmol), 2a (0.4 mmol), 3 (0.2 mmol), toluene (0.5 mL), 150 oC, 2 h, under Ar. Isolated
yields based on 3.
Scheme 3. Scope of Cyclic Ketonesa
Ph
O
NH2
NO2
R1
+
+
Ph
3a
R1
toluene, Ar
150 oC, 2 h
N
n
n
Ph
1
2a
4
1
b
1
4a
4b
4c
4d
4e
4g
4h
, R = H, 80% (61%)
, R = t-Pentyl, 81%
Ph
R1
1
1
, R = Me, 84%
, R = Ph, 82%
1
1
4i
4j
, R = Et, 69%
, R = C6H4-4-OH, 60%
1
1
N
, R = n-Pr, 64%
, R = CO2Et, 73%
1
1
Ph
4k
, R = n-Pentyl, 45%
, R = NH-COMe, 60%
1
1
4f
4l
, R = t-Bu, 93%
, R = NH-Boc, 87%
Ph
Ph
Ph
N
N
N
Ph
, 60%
Ph
Ph
Ph
4m
4n
4q
4o
, 76%
, 71%
Ph
Ph
N
N
N
Ph
, 55%
Ph
Ph
4p
4r
, 90%
, 79%
a
o
Conditions: 1 (0.4 mmol), 2a (0.4 mmol), 3a (0.2 mmol), toluene (0.5 mL), 150 C, 2 h, under Ar. Isolated
yields based on 3a. b Yield from 5 mmol scale reaction.
Under the optimized reaction conditions, the scope and generality of the three-component
reaction was explored by using various cyclic ketones (Scheme 3). Moderate to good to high
yields were obtained when electron-donating substituents presented at the para position in
cyclohexanones (4b-4g). The reaction yields decreased with the linear alkyl substituents
prolonged. When 4-tert-butylcyclohexanone was used as the substrate, the desired product 4f
was obtained in 93% yield. The desired product 4h was obtained in 82% yield when
4-phenylcyclohexanone was used as the substrate. Good yield could be achieved when a free
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hydroxy group was presented at the phenyl ring of 4-phenylcyclohexanone (4i). We
delightedly found that functional groups such as ester and amide also could be survived to
give the desired product 4j and 4k in good yield. Furthermore, 4-NH-Boc substituted
cyclohexanones also smoothly reacted in this reaction to provide the corresponding products
4l in 87% yield. When 4,4-dimethylcyclohexanone was used as the substrate, the desired
product 4m was obtained in 60% yield. The substituent position slightly affected the reaction
yield and 76% yield was gained when a methyl group was located at the meta position of
cyclohexanone (4n). When β-tetralone was employed as the substrate, 4o was obtained in
71% yield. Besides cyclohexanones, other cyclic ketones such as cycloheptanone,
cyclooctanone, cyclododecanone were also successfully participated in the reaction,
delivering the corresponding products 4p, 4q and 4r in 55%, 90% and 79% yield,
respectively. Whereas the use of non-cyclic ketones and acetophenones as reaction partners
only provided the corresponding products in trace amounts.
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Scheme 4. Scope of Aminesa
Ph
O
NO2
+
+
R NH2
Ph
toluene, Ar
150 oC, 2 h
N
R
1a
2
3a
4
Ph
2
2
4s
4y
, R = Me, 84%
, R = F, 79%
2
2
4t
4z
, R = Et, 86%
, R = Cl, 92%
2
2
4u
4v
4aa
4ab
4ac
4ad
, R = i-Pr, 74%
, R = Br, 70%
N
2
2
, R = t-Bu, 75%
, R = COMe, 60%
2
2
4w
, R = OMe, 76%
, R = NO2, 62%
2
2
4x,
R = Ph, 81%
, R = CN, 50%
R2
Ph
2
Ph
4ae
, R = 3-Me, 82%
2
4af
, R = 3-Cl, 67%
2
N
4ag
4ah
, R = 2-Me,70%
N
2
, R = 2-Cl, 58%
R2
2
4ai
4aj
, R = 2, 3-dimethyl, 68%
2
, R = 2, 4-dimethyl, 74%
4ak
, 35%
Ph
Ph
3
4ao
, R = H, 81%
3
4ap
4aq
, R = 4-Me, 71%
N
N
3
, R = 4-OMe, 53%
R
3
4ar
, R = 4-Cl, 82%
4al
4am
4an
, R = 1-naphthyl, 40%
, R = 2-naphthyl, 50%
, R = Cy, 56%
3
R3
4as
4at
, R = 3-Me, 62%
3
, R = 2-Me, 58%
a
o
Conditions: 1a (0.4 mmol), 2 (0.4 mmol), 3a (0.2 mmol), toluene (0.5 mL), 150 C, 2 h, under Ar. Isolated
yields based on 3a.
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To further investigate the scope and limitation of this three-component system, various
amines were examined under the optimized reaction conditions (Scheme 4). Anilines bearing
alkyl substituents at the para position proceeded smoothly to give the corresponding
substituted pyrrole products in good to high yields (4s-4v). p-Anisidine and 4-phenylaniline
reacted smoothly to produce the desired products in 76% and 81% yields, respectively
(4w-4x). Halogen substituents such as fluoro, chloro and bromo were all well tolerated under
the optimized reaction conditions (4y-4aa). When substrates with electron-withdrawing
groups were employed, lower yields were obtained (4ac-4ad). The position of the substituent
on the benzene ring (ortho or meta) slightly affected the reaction yields (4ae-4aj). For
example, when the methyl group was located at the meta or ortho position on the benzene ring,
the corresponding products 4ae and 4ag were obtained in 82% and 70% yields, respectively.
Anilines with two functional groups were also found to be suitable substrates to give the
corresponding products in good yields (4ai-4aj). The reaction yield decreased dramatically
when 2,4,6-trimethylaniline was used as the substrate (4ak). Moderate yield was observed
when naphthylamine were used as the substrate (4al-4am). Interestingly, aliphatic
cyclohexylamine and benzylamines also could smoothly react with 1a and 2a to give the
corresponding products in moderate to good yields (4an-4at).
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Scheme 5. Scope of Nitrovinylarenesa
R3
O
NH2
NO2
R3
R4
+
+
toluene, Ar
150 oC, 2 h
R4
N
Ph
1a
2a
3
5
R
5a
5b
5c
5d
5e
, R = Me, 70%
, R = OMe, 72%
, R = Cl, 69%
, R = Br, 73%
, R = NO2, 52%
Cl
N
Ph
, 75%
N
5f
Ph
S
N
N
N
Ph
, 51%
Ph
Ph
5i
, 72%
5g
5h
, 70%
a
o
Conditions: 1a (0.4 mmol), 2a (0.4 mmol), 3 (0.2 mmol), toluene (0.5 mL), 150 C, 2 h, under Ar. Isolated
yields based on 3.
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Subsequently, a range of nitrovinylarenes were subjected to the optimized reaction
conditions (Scheme 5). When electron-donating substituents and halogen were present at the
para position, moderate to good yields of the desired adducts were generally obtained
(5a-5d). However, 5e was obtained in low yield when a strong electron-withdrawing nitro
group was located in para position. Slightly higher yield was obtained when the chloro
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substituent
was
presented
at
the
ortho
well
5g
position
(5f).
afford
moderate
Notably,
the
(Z)-(2-nitroprop-1-en-1-yl)-benzene
reacted
to
in
2-methyl-1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole
yield.
(E)-2-(2-nitrovinyl)naphthalene and (E)-2-(2-nitrovinyl)thiophene were also suitable
substrates to afford 5h and 5i in good yields.
To obtain the corresponding indoles from the same starting materials, we further
optimized the reaction conditions via an one-pot, two-step process. After systematic
investigation of the reaction conditions, we found that the combination use of I2/DMSO could
smoothly convert the fused pyrroles into the corresponding indole products (Scheme 6). The
desired products (6a-6j) were obtained in moderate yields when the substituents were located
at the para position of cyclohexanones, anilines and nitrovinylarenes. Under the given
reaction conditions, halogen functional groups such as chloro and bromo were survived to
give the desired products in good yields.
Scheme 6. One-Pot Synthesis of Indolesa
R3
NO
2 1) toluene, Ar
O
NH2
150 oC, 2 h
R1
+
+
N
R1
R2
2) I2 (25 mol%)
DMSO (2.0 eq.)
150 oC, O2, 3 h
R3
R2
6
1
2
3
R3
R1
N
N
N
R2
1
6a
6b
6c
6d
, R = H, 66%
1
2
3
6e
6h
, R = Me, 63%
, R = Me, 60%
, R = Me, 50%
1
t
2
3
6f
6i
6j
, R = Bu, 75%
, R = OMe, 52%
, R = OMe, 58%
1
2
3
6g
, R = Ph, 58%
, R = Cl, 70%
, R = Br, 60%
a
o
Conditions: 1 (0.4 mmol), 2 (0.4 mmol), 3 (0.2 mmol), toluene (0.5 mL), 150 C, 2 h, under Ar. Then I2
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(0.05 mmol), DMSO (0.4 mmol) was added and the mixture was further stirred under O2 at 150 C for 3 h.
5
6
Isolated yields based on 3.
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Based on the observations and the literature,10, 21 a plausible mechanism is outlined in
Scheme 7. Condensation of the amino group with the carbonyl group in cyclohexanones
generates an imine intermediate A which can be transformed into intermediate B via
isomerization process. Subsequent addition of nitrovinylarene 3a to the intermediate B
affords intermediate C, which tautomerizes into the intermediate D. Then the desired cyclo
intermediate E is obtained by the cyclization of intermediate D. Finally, the elimination of water
and nitroxyl molecules affords the desired product 4a.21 Treatment of 4a with I2/DMSO
provides the final product 6a via dehydrogenative aromatization process.
Scheme 7. Proposed Mechanism
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O
NH2
H
N
N
-H2O
+
A
B
NO2
Ph
Ph
HO
O
NO2
N
OH
N
OH
Ph
Ph
H
N
N
H
N
E
C
D
-H2O
-HNO
I2/DMSO
O2
4a
6a
■ CONCLUSIONS
In summary, we have disclosed a general three-component reaction for fused pyrroles
synthesis from readily available cyclic ketones, amines and nitrovinylarenes under metal- and
additive free conditions. Active substituents such as halogens, nitro, hydroxy, ester and N-boc
groups all survived under the current reaction systems. Substituted indoles were selectively
formed from the same starting materials when the reaction was carried out under oxidative
conditions without the aid of metal-catalyst. This controllable process provides new routes to
functionalized pyrroles and indoles under metal-free conditions.
■ EXPERIMENTAL SECTION
General Information. All experiments were carried out under the standard conditions. Flash
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column chromatography was performed over silica gel (200-300 mesh). H NMR and 13C NMR
spectra were recorded on Bruker-AV (400 and 100 MHz, respectively) instrument internally
referenced to TMS, chloroform signals. MS analyses were performed on Agilent 5975 GC-MS
instrument (EI). HRMS was conducted using electrospraying ionization (ESI) and was performed
on a Thermo Scientific LTQ Orbitrap XL at Keecloud (Shanghai) Biotechnology co. LTD.
Melting points were measured with a BÜ CHI B-545 melting point instrument. The new
compounds were characterized by 1H NMR, 13C NMR, MS, and HRMS. The structures of known
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compounds were further corroborated by comparing their H NMR, 13C NMR, and MS data with
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those of literature. All ketones and amines were used as received from commercial sources
without further purification. The nitroolefins obtained by the published methods,22 and all
nitroolefins are known compounds. The 1H and 13C NMR spectra of the nitroolefins are copied in
the Supporting Information.
General Procedure for the Synthesis of Pyrroles. A oven-dried reaction vessel was
charged with nitrovinylarenes (0.2 mmol), ketones (0.4 mmol), anilines (0.4 mmol) and toluene
o
(0.5 mL). The reaction vessel was sealed under argon and stirred at 150 C for 2 h. After cooling
to room temperature, the volatiles were removed under reduced pressure. The residue was purified
by column chromatography on silica gel to give the pure product.
General Procedure for the Synthesis of Pyrroles in 5 mmol Scale. To a 25 mL pressure
tube with Teflon cover was added (E)-(2-nitrovinyl)-benzene (747.5mg, 5 mmol), cyclohexanone
(1.03 mL, 10 mmol), aniline (0.91 mL, 10 mmol) and toluene (12.5 mL). The reaction vessel was
o
sealed under argon and stirred at 150 C for 2 h. After cooling to room temperature, the volatiles
were removed under reduced pressure. The residue was purified by column chromatography on
silica gel (petroleum ether) to give the desired product 4a as yellow solid (831 mg, 61% yield).
General Procedure for the One-Pot Synthesis of Indoles. A oven-dried reaction vessel was
charged with nitrovinylarenes (0.2 mmol), ketones (0.4 mmol), anilines (0.4 mmol) and toluene
o
(0.5 mL). The reaction vessel was sealed under argon and stirred at 150 C for 2 h. After cooling
to room temperature, I2 (12.7 mg, 25 mol%) , DMSO (28.4 μL, 0.4 mmol ) was added and the
o
resulting solution was sealed under oxygen. The reaction vessel was stirred at 150 C for 3 h.
After cooling to room temperature, the volatiles were removed under reduced pressure. The
residue was purified by column chromatography on silica gel to give the pure product.
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1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole (4a). Yellow solid (43.8 mg, yield 80%,
petroleum ether), mp 55-57 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.51 (d, J = 8.0 Hz, 2H), 7.45
(t, J = 8.0 Hz, 2H), 7.39-7.30 (m, 6H), 7.22 (t, J = 8.0 Hz, 1H), 2.79 (t, J = 6.0 Hz, 2H), 2.63 (t, J
= 6.0 Hz, 2H), 1.85-1.82 (m, 4H).13C{1H} NMR (100 MHz, CDCl3, ppm) 139.9, 136.1, 129.2,
129.1, 128.4, 126.9, 126.3, 125.3, 124.6, 123.7, 117.6, 117.1, 23.6, 23.5, 23.5, 23.2. HRMS (ESI,
m/z): calcd for: C20H20N+ [M+H]+, 274.1590; found 274.1591.
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5-methyl-1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole (4b). Yellow solid (48.3 mg, yield
84%, petroleum ether), mp 92-94 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.50 (d, J = 8.0 Hz, 2H),
7.45 (t, J = 8.0 Hz, 2H), 7.37 (t, J = 8.0 Hz, 4H), 7.32 (t, J = 8.0 Hz, 1H), 7.22 (t, J = 8.0 Hz, 1H),
6.99 (s, 1H), 2.85 (dd, J = 15.5, 5.0 Hz, 1H), 2.75-2.58 (m, 2H), 2.39 (dd, J = 15.6, 9.9 Hz, 1H),
1.93-1.89 (m, 2H), 1.52-1.42 (m, 1H), 1.12 (d, J = 8.0 Hz, 3H). 13C{1H} NMR (100 MHz, CDCl3,
ppm) δ 140.0, 136.1, 129.1, 128.9, 128.4, 126.9, 126.3, 125.3, 124.5, 123.6, 117.8, 117.2, 32.1,
31.5, 29.9, 23.3, 21.9. HRMS (ESI) m/z calcd for C21H22N+ [M+H]+ 288.1747, found 288.1745.
5-ethyl-1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole (4c). Yellow solid (41.4 mg, yield 69%,
petroleum ether), mp 63-64 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.50 (d, J = 8.0 Hz, 2H), 7.44
(t, J = 8.0 Hz, 2H), 7.40-7.35 (m, 4H), 7.31 (t, J = 6.0 Hz, 1H), 7.22 (t, J = 8.0 Hz, 1H), 6.99 (s,
1H), 2.88 (dd, J = 15.4, 5.0 Hz, 1H), 2.74-2.59 (m, 2H), 2.39 (dd, J = 15.5, 10.0 Hz, 1H), 1.97 (d,
J = 12.0 Hz, 1H), 1.69-1.60 (m, 1H), 1.46 (p, J = 8.0 Hz, 3H), 0.99 (t, J = 8.0 Hz, 3H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 140.0, 136.1, 129.2, 129.1, 128.4, 127.0, 126.3, 125.3, 124.5,
123.7, 117.8, 117.1, 36.7, 29.7, 29.3, 29.1, 23.4, 11.8. HRMS (ESI) m/z calcd for C22H24N+
[M+H]+ 302.1903, found 302.1908.
1,3-diphenyl-5-propyl-4,5,6,7-tetrahydro-1H-indole (4d). Yellow solid (40.6 mg, yield
64%, petroleum ether), mp 52-54 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.51 (d, J = 8.0 Hz, 2H),
7.45 (t, J = 8.0 Hz, 2H), 7.40-7.36 (m, 4H), 7.32 (t, J = 8.0 Hz, 1H), 7.23 (t, J = 8.0 Hz, 1H), 7.00
(s, 1H), 2.88 (dd, J = 15.5, 5.0 Hz, 1H), 2.74-2.58 (m, 2H), 2.42-2.36 (m, 1H), 1.98-1.93 (m, 1H),
1.77-1.73 (m, 1H), 1.49-1.38 (m, 5H), 0.94 (t, J = 6.0 Hz, 3H). 13C{1H} NMR (100 MHz, CDCl3,
ppm) δ 140.0, 136.1, 129.2, 129.1, 128.4, 126.9, 126.2, 125.3, 124.5, 123.7, 117.8, 117.1, 38.7,
34.6, 30.0, 29.7, 23.4, 20.2, 14.3. HRMS (ESI) m/z calcd for C23H26N+ [M+H]+ 316.2060, found
316.2058.
5-pentyl-1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole (4e). Yellow solid (31.0 mg, yield
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45%, petroleum ether), mp 44-46 °C.1H NMR (400 MHz, CDCl3, ppm) δ 7.50 (d, J = 8.0 Hz, 2H),
7.44 (t, J = 8.0 Hz, 2H), 7.40-7.35 (m, 4H), 7.31 (t, J = 8.0 Hz, 1H), 7.22 (t, J = 8.0 Hz, 1H), 6.99
(s, 1H), 2.87 (dd, J = 15.3, 4.8 Hz, 1H), 2.73-2.58 (m, 2H), 2.38 (dd, J = 15.3, 10.1 Hz, 1H), 1.96
(d, J = 12.0 Hz, 1H), 1.73 (s, 1H), 1.50-1.27 (m, 9H), 0.89 (t, J = 6.0 Hz, 3H). 13C{1H} NMR (100
MHz, CDCl3, ppm) δ 140.0, 136.1, 129.2, 129.1, 128.4, 127.0, 126.3, 125.4, 124.5, 123.7, 117.8,
117.2, 36.4, 35.0, 32.2, 30.1, 29.7, 26.9, 23.4, 22.7, 14.2. HRMS (ESI) m/z calcd for C25H30N+
[M+H]+ 344.2373, found 344.2373.
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5-(tert-butyl)-1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole (4f). Yellow solid (61.0 mg,
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yield 93%, petroleum ether), mp 51-53 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.51 (d, J = 8.0
Hz, 2H), 7.46-7.29 (m, 8H), 7.23 (t, J = 8.0 Hz, 1H), 2.81 (dd, J = 15.2, 4.3 Hz, 1H), 2.70-2.62 (m,
2H), 2.53 (t, J = 12.0 Hz,1H), 2.06 (d, J = 11.6 Hz, 1H), 1.53-1.35 (m, 2H), 0.97 (s, 9H).13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 140.0, 136.1, 129.3, 129.1, 128.5, 127.0, 126.2, 125.4, 124.4,
123.9, 117.8, 117.6, 45.57, 32.53, 27.5, 24.8, 24.7, 24.5. HRMS (ESI, m/z): calcd for: C24H28N+
[M+H]+ 330.2216, found 330.2218.
5-(tert-pentyl)-1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole (4g). Yellow solid (55.8 mg,
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yield 81%, petroleum ether), mp 36-37 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.51 (d, J = 7.9
Hz, 2H), 7.46-7.29 (m, 8H), 7.23 (t, J = 8.0 Hz, 1H), 2.77-2.51 (m, 4H), 2.01 (d, J = 12.0 Hz, 1H),
1.65-1.61 (m, 1H), 1.45-1.32 (m, 3H), 0.91 (d, J = 4.0 Hz, 6H), 0.83 (t, J = 8.0 Hz, 3H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 140.0, 136.1, 129.3, 129.1, 128.4, 127.0, 126.2, 125.4, 124.4,
123.9, 117.8, 117.7, 42.9, 34.8, 32.7, 24.5, 24.3, 24.3, 24.2, 24.1, 8.2. HRMS (ESI) m/z calcd for
C25H30N+ [M+H]+ 344.2372, found 344.2373.
1,3,5-triphenyl-4,5,6,7-tetrahydro-1H-indole (4h). Yellow solid (57.5 mg, yield 82%,
petroleum ether). mp 90-92 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.50-7.45 (m, 4H), 7.39 (d, J
= 4.0 Hz, 2H), 7.34 (d, J = 8.0 Hz, 7H), 7.25-7.23 (m, 1H), 7.20 (t, J = 8.0 Hz, 1H), 7.05 (s, 1H),
3.11-3.00 (m, 2H), 2.93-2.83 (m, 2H), 2.76-2.71 (m, 1H), 2.19-2.16 (m, 1H), 2.07 (m, 1H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 146.8, 139.9, 135.75, 129.2, 128.8, 128. 4, 128.4, 127.0, 127.0,
126.5, 126.2, 125.5, 124.6, 123.6, 118.0, 117.2, 41.6, 32.4, 30.0, 23.9. HRMS (ESI) m/z calcd for
C26H24N+ [M+H]+ 350.1903, found 350.1906.
4-(1,3-diphenyl-4,5,6,7-tetrahydro-1H-indol-5-yl)phenol (4i). Yellow solid (45.1 mg, yield
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62%, petroleum ether/ethyl acetate = 5:1), mp 119-122 °C. H NMR (400 MHz, CDCl3, ppm) δ
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7.49-7.44 (m, 5H), 7.39-7.32 (m, 6H), 7.19 (d, J = 8.0 Hz, 3H), 6.81 (d, J = 8.0 Hz, 2H), 3.05 (dd,
J = 14.6, 4.5 Hz, 1H), 2.99-2.93 (m, 1H), 2.87-2.81 (m, 2H), 2.74-2.69 (m, 1H), 2.15-2.11 (m, 1H),
2.05-1.95 (m, 1H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 153.8, 139.9, 139.1, 135.8, 129.2,
128.8, 128.4, 128.0, 126.9, 126.4, 125.4, 124.6, 123.5, 118.0, 117.2, 115.2, 40.69, 32.5, 30.3, 23.8.
HRMS (ESI) m/z calcd for C26H24NO+ [M+H]+ 366.1852, found 366.1857.
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Ethyl 1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole-5-carboxylate (4j). Yellow solid (50.4
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mg, yield 73%, petroleum ether/ethyl acetate = 20:1), mp 70-71 °C. H NMR (400 MHz, CDCl3,
ppm) δ 7.46 (q, J = 8.0, 4H), 7.39-7.31 (m, 5H), 7.22 (t, J = 6.0 Hz, 1H), 6.99 (s, 1H), 4.18 (q, J
=6.7 Hz, 2H), 3.08-2.95 (m, 2H), 2.78-2.67 (m, 3H), 2.27-2.23 (m, 1H), 1.96-1.85 (m, 1H), 1.28 (t,
J = 6.0 Hz, 3H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 175.6, 139.7, 135.6, 129.1, 128.4,
128.1, 126.9, 126.5, 125.5, 124.5, 123.7, 118.1, 115.5, 60.4, 40.7, 26.1, 25.9, 22.7, 14.2. HRMS
(ESI) m/z calcd for C23H24NO2+ [M+H]+ 346.1802, found 346.1805.
N-(1,3-diphenyl-4,5,6,7-tetrahydro-1H-indol-5-yl)acetamide (4k). Yellow solid (39.8 mg,
yield 60%, petroleum ether/ethyl acetate = 1:1), mp 140-142 °C. 1H NMR (400 MHz, CDCl3, ppm)
δ 7.46 (t, J = 8.0 Hz, 4H), 7.38-7.32 (m, 5H), 7.22 (t, J = 8.0 Hz, 1H), 7.01 (s, 1H), 5.68 (d, J = 4.0
Hz, 1H), 4.43-4.36 (m, 1H), 3.15 (dd, J = 15.5, 5.2 Hz, 1H), 2.80-2.73 (m, 1H), 2.69-2.62 (m, 2H),
2.04-1.88 (m, 5H).13C{1H} NMR (100 MHz, CDCl3, ppm) δ 169.6, 139.6, 135.5, 129.2, 128.5,
127.8, 126.8, 126.6, 125.6, 124.5, 123.8, 118.4, 114.3, 45.3, 30.0, 28.0, 23.5, 20.6. HRMS (ESI)
m/z calcd for C22H23N2O+ [M+H]+ 331.1805, found 331.1803.
Tert-butyl (1,3-diphenyl-4,5,6,7-tetrahydro-1H-indol-5-yl)carbamate (4l). Yellow solid
(67.5 mg, yield 87%, petroleum ether/ethyl acetate = 10:1), mp 133-135 °C. 1H NMR (400 MHz,
CDCl3, ppm) δ 7.45 (d, J = 8.0 Hz, 4H), 7.38-7.31 (m, 5H), 7.22 (t, J = 8.0 Hz, 1H), 6.99 (s, 1H),
4.73 (d, J = 4.0 Hz, 1H), 4.11-4.04 (m, 1H), 3.13 (dd, J = 15.5, 5.2 Hz, 1H), 2.76-2.62 (m, 3H),
2.07-2.00 (m, 1H), 1.91-1.82 (m, 1H), 1.45 (s, 9H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ
155.3, 139.7, 135.6, 129.2, 128.5, 127.8, 126.9, 126.6, 125.6, 124.6, 123.9, 118.4, 114.6, 79.1,
+
46.4, 30.4, 28.6, 28.4, 20.8. HRMS (ESI) m/z calcd for C25H29N2O2 [M+H]+ 389.2224, found
389.2220.
5,5-dimethyl-1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole (4m). Yellow solid (36.3 mg,
yield 60%, petroleum ether), mp 67-69 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.50-7.43 (m, 4H),
7.39-7.35 (m, 4H), 7.31 (t, J = 6.0 Hz, 1H), 7.21 (t, J = 6.0 Hz, 1H), 7.01 (s, 1H), 2.62 (t, J = 8.0
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Hz, 2H), 2.58 (s, 2H), 1.60 (t, J = 6.0 Hz, 2H), 1.05 (s, 6H). 13C{1H} NMR (100 MHz, CDCl3,
ppm) δ 140.1, 136.2, 129.1, 128.4, 127.8, 127.0, 126.2, 125.3, 124.5, 123.9, 118.0, 116.7, 37.4,
36.0, 30.1, 28.1, 20.8. HRMS (ESI) m/z calcd for C22H24N+ [M+H]+ 302.1903, found 302.1904.
6-methyl-1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole (4n). Yellow solid (43.6 mg, yield
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76%, petroleum ether), mp 118-120 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.52 (d, J = 8.0 Hz,
2H), 7.46 (t, J = 8.0 Hz, 2H), 7.39-7.31 (m, 5H), 7.22 (t, J = 8.0 Hz, 1H), 7.01 (s, 1H), 2.88-2.76
(m, 2H), 2.64 (dd, J = 15.7, 5.0 Hz, 1H), 2.33-2.27 (m, 1H), 1.95-1.92 (m, 2H), 1.50-1.40 (m, 1H),
1.09 (d, J = 8.0 Hz, 3H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 139.9, 136.1, 129.2, 129.1,
128.4, 126.9, 126.3, 125.3, 124.7, 123.5, 117.8, 116.9, 32.0, 32.0, 29.7, 23.2, 21.9. HRMS (ESI)
m/z calcd for C21H22N+ [M+H]+ 288.1747, found 288.1745.
1,3-diphenyl-4,5-dihydro-3H-benzo[e]indole (4o). Brown solid (45.6 mg, yield 71%,
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petroleum ether), mp 155-157 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.55 (d, J = 4.0 Hz, 2H),
7.48 (t, J = 6.0 Hz, 2H), 7.42-7.30 (m, 6H), 7.22 (t, J = 6.0 Hz, 2H), 7.02 (t, J = 6.0 Hz, 2H), 6.89
(s, 1H), 3.00 (t, J = 6.0 Hz, 2H), 2.81 (t, J = 6.0 Hz, 2H). 13C{1H} NMR (100 MHz, CDCl3, ppm)
δ 139.1, 136.1, 134.1, 133.2, 131.8, 129.2, 128.8, 128.3, 127.8, 126.7, 126.2, 126.2, 124.5, 124.4,
123.3, 123.2, 120.2, 117.2, 30.4, 21.8. HRMS (ESI) m/z calcd for C24H20N+ [M+H]+ 322.1590,
found 322.1592.
1,3-diphenyl-1,4,5,6,7,8-hexahydrocyclohepta[b]pyrrole (4p). Yellow solid (31.8 mg,
yield 55%, petroleum ether), mp 82-84 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.45-7.33 (m, 7H),
7.30 (d, J = 8.0 Hz, 2H), 7.23 (t, J = 6.0 Hz, 1H), 6.72 (s, 1H), 2.76 (t, J = 6.0 Hz, 2H), 2.69 (t, J =
6.0 Hz, 2H), 1.88-1.83 (m, 2H), 1.73-1.64 (m 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ
140.1, 136.3, 132.8, 128.9, 128.6, 128.2, 126.7, 126.1, 125.5, 124.9, 121.6, 117.5, 32.1, 28.5, 27.3,
26.8, 25.7. HRMS (ESI) m/z calcd for C21H22N+ [M+H]+ 288.1747, found 288.1745.
1,3-diphenyl-4,5,6,7,8,9-hexahydro-1H-cycloocta[b]pyrrole (4q). Yellow solid (54.2 mg,
yield 90%, petroleum ether), mp 62-64 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.45 (t, J = 8.0 Hz,
4H), 7.39-7.34 (m, 5H), 7.23 (t, J = 8.0 Hz, 1H), 6.83 (s, 1H), 2.74 (t, J = 6.0 Hz, 2H), 2.67 ((t, J =
6.0 Hz, 2H), 1.79-1.71 (m, 2H), 1.60-1.49 (m, 6H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ
140.3, 136.5, 131.2, 129.0, 128.3, 128.0, 126.9, 126.2, 125.4, 124.4, 119.2, 118.4, 31.2, 30.3, 26.1,
26.0, 23.4, 23.4. HRMS (ESI) m/z calcd for C22H24N+ [M+H]+ 302.1903, found 302.1906.
1,3-diphenyl-4,5,6,7,8,9,10,11,12,13-decahydro-1H-cyclododeca[b]pyrrole (4r). Yellow
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solid (56.2 mg, yield 79%, petroleum ether), mp 78-80 °C. H NMR (400 MHz, CDCl3, ppm) δ
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7.50 (d, J = 8.0 Hz, 2H), 7.45 (t, J = 8.0 Hz, 2H), 7.39-7.34 (m, 5H), 7.22 (t, J = 6.0 Hz, 1H), 6.78
(s, 1H), 2.72-2.66 (m, 4H), 1.51-1.42 (m, 6H), 1.35 (s, 4H), 1.26-1.19 (m, 6H). 13C{1H} NMR
(100 MHz, CDCl3, ppm) δ 141.0, 137.1, 131.5, 129.0, 128.2, 127.6, 126.9, 126.1, 125.4, 124.2,
120.3, 119.9, 28.2, 27.2, 25.5, 25.4, 24.9, 24.9, 22.6, 22.5, 22.3, 21.5. HRMS (ESI) m/z calcd for
C26H32N+ [M+H]+ 358.2529, found 358.2524.
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3-phenyl-1-(p-tolyl)-4,5,6,7-tetrahydro-1H-indole (4s) Yellow solid (48.2 mg, yield 84%,
petroleum ether), mp 87-89 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.51 (d, J = 8.0 Hz, 2H), 7.37
(t, J = 8.0 Hz, 2H), 7.25 (s, 5H), 7.21 (t, J = 8.0 Hz, 1H), 2.79 (t, J = 6.0 Hz, 2H), 2.61 (t, J = 6.0
Hz, 2H), 2.41 (s, 3H), 1.85-1.82 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 137.4, 136.2,
136.1, 129.7, 129.2, 128.4, 126.9, 125.2, 124.6, 123.4, 117.6, 116.8, 23.6, 23.5, 23.2, 21.0. HRMS
(ESI) m/z calcd for C21H22N+ [M+H]+ 288.1747, found 288.1745.
1-(4-ethylphenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4t). Yellow solid (51.6 mg,
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yield 86%, petroleum ether), mp 70-72 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.50 (d, J = 8.0
Hz, 2H), 7.37 (t, J = 6.0 Hz, 2H), 7.27 (s, 5H), 7.21 (t, J = 8.0 Hz, 1H), 2.79 (t, J = 6.0 Hz, 2H),
2.71 (q, J = 8.0Hz, 2H), 2.61 (t, J = 6.0 Hz, 2H), 1.85-1.81 (m, 4H) (s, 4H), 1.29 (t, J = 8.0 Hz,
3H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 142.4, 137.5, 136.1, 129.2, 128.4, 128.4, 126.9,
125.2, 124.6, 123.4, 117.6, 116.8, 28.3, 23.6, 23.5, 23.2, 15.5. HRMS (ESI) m/z calcd for
C22H24N+ [M+H]+ 302.1903, found 302.1908.
1-(4-isopropylphenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4u). Yellow solid (46.6 mg,
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yield 74%, petroleum ether), mp 67-68 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.51 (d, J = 8.0
Hz, 2H), 7.37 (t, J = 8.0 Hz, 2H), 7.29 (s, 5H), 7.21 (t, J = 8.0 Hz, 1H), 3.00-2.93 (m, 1H), 2.79 (t,
J = 6.0 Hz, 2H), 2.62 (t, J = 6.0 Hz, 2H), 1.85-1.82 (m, 4H), 1.30 (d, J = 8.0 Hz, 6H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 147.0, 137.6, 136.2, 129.3, 128.4, 127.0, 126.9, 125.2, 124.6,
123.4, 117.7, 116.8, 33.7, 24.0, 23.6, 23.5, 23.5, 23.2. HRMS (ESI) m/z calcd for C23H26N+
[M+H]+ 316.2060, found 316.2059.
1-(4-(tert-butyl)phenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4v). Yellow solid (49.3
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mg, yield 75%, petroleum ether), mp 90-91 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.50 (d, J =
8.0 Hz, 2H), 7.45 (d, J = 8.0 Hz, 2H), 7.36 (t, J = 7.6 Hz, 2H), 7.28 (d, J = 8.0 Hz, 3H), 7.21 (t, J
= 8.0 Hz, 1H), 2.79 (t, J = 6.0 Hz, 2H), 2.62 (t, J = 6.0 Hz, 2H), 1.85-1.82 (m, 4H), 1.37 (s, 9H).
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13C{1H} NMR (100 MHz, CDCl3, ppm) δ 149.3, 137.3, 136.2, 129.3, 128.4, 126.9, 126.0, 125.2,
124.2, 123.4, 117.6, 116.8, 34.5, 31.4, 23.6, 23.6, 23.5, 23.2. HRMS (ESI, m/z): calcd for:
C24H28N+ [M+H]+ 330.2216, found 330.2218.
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1-(4-methoxyphenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4w). Yellow solid (46.1 mg,
yield 76%, petroleum ether/ethyl acetate = 100:1), mp 74-75 °C. 1H NMR (400 MHz, CDCl3, ppm)
δ 7.50 (d, J = 8.0 Hz, 2H), 7.36 (t, J = 8.0 Hz, 2H), 7.28 (d, J = 8.0 Hz, 3H), 7.21 (t, J = 7.4 Hz,
1H), 6.97 (d, J = 12.0 Hz, 2H), 3.86 (s, 3H), 2.80-2.77 (t, J = 6.0 Hz, 2H), 2.58-2.55 (t, J = 6.0 Hz,
2H), 1.85-1.81 (m, 4H).13C{1H} NMR (100 MHz, CDCl3, ppm) δ 158.1, 136.2, 133.0, 129.4,
128.4, 126.9, 126.1, 125.2, 123.2, 117.8, 116.5, 114.2, 55.5, 23.6, 23.5, 23.3, 23.2. HRMS (ESI)
m/z calcd for C21H22NO+ [M+H]+ 304.1696, found 304.1698.
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1-([1,1'-biphenyl]-4-yl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4x). Yellow solid (56.8
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mg, yield 81%, petroleum ether/ethyl acetate = 100:1), mp 150-152 °C. H NMR (400 MHz,
CDCl3, ppm) δ 7.65 (q, J = 8.0 Hz, 4H), 7.53-7.36 (m, 10H), 7.23 (t, J = 8.0 Hz, 1H), 2.80 (t, J
=6.0 Hz, 2H), 2.69 (t, J = 6.0 Hz, 2H), 1.87-1.84 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm)
δ 140.2, 139.2, 139.1, 136.0, 129.2, 128.8, 128.4, 127.8, 127.4, 127.0, 127.0, 125.4, 124.8, 123.9,
117.5, 117.3, 23.7, 23.5, 23.5, 23.2. HRMS (ESI) m/z calcd for C26H24N+ [M+H]+ 350.1903,
found 350.1906.
1-(4-fluorophenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4y). Yellow solid (45.8 mg,
yield 79%, petroleum ether), mp 69-71 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.49 (dd, J = 8.2,
1.4 Hz, 2H), 7.37 (t, J = 8.0 Hz, 2H), 7.32 (q, J = 4.0 Hz, 2H), 7.22 (t, J = 8.0 Hz, 1H), 7.13 (t, J =
8.0 Hz, 2H), 6.93 (s, 1H), 2.77 (t, J = 6.0 Hz, 2H), 2.57 (t, J = 6.0 Hz, 2H), 1.85-1.80 (m, 4H).
13C{1H} NMR (100 MHz, CDCl3, ppm) δ 161.1(d, J = 245 Hz), 136.0(d, J = 3 Hz), 135.9, 129.3,
128.4, 126.9, 126.4(d, J = 9 Hz), 125.4, 123.8, 117.7, 117.1, 115.9(d, J = 23 Hz), 23.5, 23.4, 23.4,
23.2. HRMS (ESI) m/z calcd for C21H19FN+ [M+H]+ 292.1496, found 292.1494.
1-(4-chlorophenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4z). Yellow solid (56.5 mg,
yield 92%, petroleum ether), mp 137-139 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.48 (d, J = 4.0
Hz, 2H), 7.42-7.35 (m, 4H), 7.29 (d, J = 8.0 Hz, 2H), 7.22 (t, J = 8.0 Hz, 1H), 6.94 (s, 1H), 2.76 (t,
J = 6.0 Hz, 2H), 2.59 (t, J = 4.0 Hz, 2H), 1.86-1.79 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3,
ppm) δ 138.4, 135.8, 131.9, 129.2, 129.1, 128.4, 126.9, 125.7, 125.5, 124.2, 117.6, 117.4, 23.5,
23.4, 23.4, 23.2. HRMS (ESI) m/z calcd for C20H19ClN+ [M+H]+ 308.1201, found 308.1203.
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1-(4-bromophenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4aa). Yellow solid (48.8 mg,
yield 70%, petroleum ether), mp 108-111 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.56 (d, J = 8.0
Hz, 2H), 7.49 (d, J = 8.0 Hz, 2H), 7.37 (t, J = 8.0 Hz, 2H), 7.23 (d, J = 8.0 Hz, 4H), 2.76 (t, J =
6.0 Hz, 2H), 2.59 (t, J = 4.0 Hz, 2H), 1.86-1.79 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ
138.9, 135.8, 132.2, 129.0, 128.4, 126.9, 126.0, 125.5, 124.2, 119.7, 117.6, 117.3, 23.6, 23.4, 23.4,
23.2. HRMS (ESI) m/z calcd for C20H19BrN+ [M+H]+ 352.0695, found 352.0697.
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1-(4-(3-phenyl-4,5,6,7-tetrahydro-1H-indol-1-yl)phenyl) ethan-1-one (4ab). Yellow solid
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(37.5 mg, yield 60%, petroleum ether/ethyl acetate = 10:1) mp 136-137 °C. H NMR (400 MHz,
CDCl3, ppm) δ 8.05 (d, J = 8.0 Hz, 2H), 7.50 (d, J = 8.0 Hz, 2H), 7.45 (d, J = 12.0 Hz, 2H), 7.38 (t,
J = 8.0 Hz, 2H), 7.24 (t, J = 8.0 Hz, 1H), 7.02 (s, 1H), 2.77 (t, J = 4.0 Hz, 2H), 2.68 (t, J = 6.0 Hz,
2H), 2.64 (s, 3H), 1.85-1.83 (m, 4H). 13C{1H} NMR (101 MHz, CDCl3, ppm) δ 197.0, 143.8,
135.6, 134.4, 129.6, 129.0, 128.4, 127.0, 125.7, 124.9, 123.6, 118.6, 117.2, 26.6, 24.0, 23.4, 23.3,
23.2. HRMS (ESI) m/z calcd for C22H22NO+ [M+H]+ 316.1696, found 316.1697.
1-(4-nitrophenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4ac). Yellow solid (39.5mg,
yield 62%, petroleum ether/ethyl acetate = 50:1), mp 89-90 °C. 1H NMR (400 MHz, CDCl3, ppm)
δ 8.33 (d, J = 8.9 Hz, 2H), 7.49 (dd, J = 8.0, 5.7 Hz, 4H), 7.39 (t, J = 7.7 Hz, 2H), 7.26 (t, J = 8.0
Hz, 2H), 7.03 (s, 1H), 2.76 (t, J = 4.0 Hz, 2H), 2.69 (t, J = 6.0 Hz, 2H), 1.87-1.83 (m, 4H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 145.2, 145.0, 135.2, 129.1, 128.5, 127.1, 126.0, 125.8, 125.0,
+
123.6, 119.6, 117.1, 24.2, 23.4, 23.2, 23.2. HRMS (ESI) m/z calcd for C20H19N2O2 [M+H]+
319.1441, found 319.1441.
4-(3-phenyl-4,5,6,7-tetrahydro-1H-indol-1-yl)benzonitrile (4ad). Yellow solid (29.7 mg,
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yield 50%, petroleum ether/ethyl acetate = 50:1), mp 126-129 °C. H NMR (400 MHz, CDCl3,
ppm) δ 7.74 (d, J = 8.0 Hz, 2H), 7.47 (t, J = 8.2 Hz, 4H), 7.38 (t, J = 7.7 Hz, 2H), 7.25 (t, J = 6.0
Hz, 1H), 6.99 (s, 1H), 2.76 (t, J =6.0 Hz, 2H), 2.66 (t, J =6.0 Hz, 2H), 1.85-1.82 (m, 4H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 143.5, 135.3, 133.3, 129.0, 128.5, 127.0, 125.9, 125.5, 124.1,
+
119.1, 118.5, 117.0, 109.2, 24.0, 23.4, 23.2, 23.2. HRMS (ESI) m/z calcd for C21H19N2 [M+H]+
299.1543, found 299.1542.
3-phenyl-1-(m-tolyl)-4,5,6,7-tetrahydro-1H-indole (4ae). Yellow liquid (47.2 mg, yield
82%, petroleum ether). 1H NMR (400 MHz, CDCl3, ppm) δ 7.51 (d, J = 8.0 Hz, 2H), 7.39-7.31 (m,
3H), 7.23-7.13 (m, 4H), 6.98 (s, 1H), 2.79 (t, J = 6.0 Hz, 2H), 2.62 (t, J = 6.0 Hz, 2H), 2.42 (s, 3H),
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1.85-1.82 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 139.8, 139.0, 136.2, 129.1, 128.8,
128.3, 127.1, 126.9, 125.3, 125.2, 123.6, 121.7, 117.6, 117.0, 23.6, 23.6, 23.5, 23.2, 21.4. HRMS
(ESI) m/z calcd for C21H22N+ [M+H]+ 288.1747, found 288.1745.
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1-(3-chlorophenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4af). Yellow solid (41.4 mg,
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yield 67%, petroleum ether), mp 82-84 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.49 (d, J = 7.1
Hz, 2H), 7.37 (t, J = 7.8 Hz, 4H), 7.30-7.21 (m, 3H), 6.96 (s, 1H), 2.77 (t, J = 4.6 Hz, 2H), 2.63 (t,
J = 4.7 Hz, 2H), 1.87-1.80 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 141.0, 135.8, 134.7,
130.1, 129.1, 128.4, 127.0, 126.3, 125.5, 124.7, 124.3, 122.6, 117.8, 117.4, 23.6, 23.4, 23.2.
HRMS (ESI) m/z calcd for C20H19ClN+ [M+H]+ 308.1201, found 308.1203.
3-phenyl-1-(o-tolyl)-4,5,6,7-tetrahydro-1H-indole (4ag). Yellow solid (40.4 mg, yield 70%,
petroleum ether), mp 78-81 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.50 (d, J = 7.8 Hz, 2H), 7.34
(t, J = 7.7 Hz, 2H), 7.30 (d, J = 3.2 Hz, 2H), 7.25 (t, J = 3.3 Hz, 2H), 7.18 (t, J = 7.4 Hz, 1H), 6.80
(s, 1H), 2.79 (t, J = 4.0 Hz, 2H), 2.43-2.26 (m, 2H), 2.11 (s, 3H), 1.82-1.78 (m, 4H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 139.0, 136.5, 135.9, 130.7, 130.0, 128.4, 128.0, 128.0, 126.7,
126.3, 125.0, 122.7, 117.8, 115.5, 23.8, 23.6, 23.0, 22.5, 17.5. HRMS (ESI) m/z calcd for
C21H22N+ [M+H]+ 288.1747, found 288.1745.
1-(2-chlorophenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4ah). Yellow solid (35.4 mg,
yield 58%, petroleum ether), mp 42-43 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.54-7.50 (m, 3H),
7.37-7.33 (m, 5H), 7.19 (t, J = 7.4 Hz, 1H), 6.86 (s, 1H), 2.79 (d, J = 4.0 Hz, 2H), 2.38 (t, J = 6.0
Hz, 2H), 1.83-1.80 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 137.6, 136.1, 132.1, 130.4,
130.3, 129.6, 129.0, 128.3, 127.3, 126.8, 125.2, 123.4, 118.1, 116.0, 23.7, 23.5, 22.9, 22.4. HRMS
(ESI) m/z calcd for C20H19ClN+ [M+H]+ 308.1201, found 308.1203.
1-(2,3-dimethylphenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4ai). Yellow solid (40.7
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mg, yield 68%, petroleum ether), mp 82-84 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.51 (d, J =
8.1 Hz, 2H), 7.35 (t, J = 7.7 Hz, 2H), 7.21-7.16 (m, 3H), 7.13 (t, J = 6.3 Hz, 1H), 6.80 (s, 1H),
2.80 (t, J = 4.9 Hz, 2H), 2.34 (s, 4H), 2.21-2.17 (m, 1H), 1.96 (s, 3H), 1.83-1.79 (m, 4H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 139.0, 138.0, 136.5, 134.7, 130.3, 129.5, 128.4, 126.6, 125.6,
125.0, 122.6, 118.1, 115.3, 23.9, 23.6, 23.0, 22.5, 20.4, 14.2. HRMS (ESI) m/z calcd for C22H24N+
[M+H]+ 302.1903, found 302.1907.
1-(2,4-dimethylphenyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4aj). Yellow liquid (44.8
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mg, yield 74%, petroleum ether). H NMR (400 MHz, CDCl3, ppm) δ 7.50 (d, J = 7.8 Hz, 2H),
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7.35 (t, J = 7.7 Hz, 2H), 7.20-7.12 (m, 3H), 7.06 (d, J = 8.1 Hz, 1H), 6.79 (s, 1H), 2.79 (t, J = 6.0
Hz, 2H), 2.38 (s, 3H), 2.33-2.19 (m, 2H), 2.07 (s, 3H), 1.82-1.79 (m, 4H). 13C{1H} NMR (100
MHz, CDCl3, ppm) δ 137.8, 136.5, 136.4, 135.5, 131.3, 130.0, 128.3, 127.7, 126.9, 126.6, 124.9,
122.6, 117.9, 115.3, 23.8, 23.6, 23.0, 22.5, 21.0, 17.4. HRMS (ESI) m/z calcd for C22H24N+
[M+H]+ 302.1903, found 302.1907.
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1-mesityl-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4ak). Yellow liquid (22.2 mg, yield 35%,
petroleum ether). 1H NMR (400 MHz, CDCl3, ppm) δ 7.51 (d, J = 7.1 Hz, 2H), 7.34 (t, J = 7.7 Hz,
2H), 7.16 (t, J = 7.4 Hz, 1H), 6.95 (s, 2H), 6.69 (s, 1H), 2.82-2.78 (m, 2H), 2.34 (s, 3H), 2.17-2.13
(m, 2H), 1.99 (s, 6H), 1.81-1.78 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 137.7, 136.8,
136.4, 135.6, 129.3, 128.5, 128.4, 126.4, 124.8, 122.7, 116.6, 115.2, 24.0, 23.8, 23.0, 22.2, 21.0,
17.5. HRMS (ESI) m/z calcd for C23H26N+ [M+H]+ 316.2060, found 316.2058.
1-(naphthalen-1-yl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4al). Brown solid (25.9 mg,
yield 40%, petroleum ether), mp 72-73 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.92 (t, J = 7.7 Hz,
2H), 7.57-7.52 (m, 5H), 7.50-7.47 (m, 2H), 7.38 (t, J = 7.7 Hz, 2H), 7.21 (t, J = 7.4 Hz, 1H), 7.01
(s, 1H), 2.86 (t, J = 4.0 Hz, 2H), 2.41-2.34 (m, 1H), 2.22-2.16 (m, 1H), 1.88-1.75 (m, 4H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 136.6, 136.3, 134.1, 131.2, 131.0, 128.4, 128.2, 128.0, 127.0,
126.7, 126.5, 125.2, 125.1, 124.9, 123.7, 122.9, 119.4, 115.8, 23.8, 23.6, 23.0, 22.5. HRMS (ESI)
m/z calcd for C24H22N+ [M+H]+ 324.1747, found 324.1756.
1-(naphthalen-2-yl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4am). Brown solid (32.4 mg,
yield 50%, petroleum ether), mp 55-57 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.88 (m, 3H), 7.79
(s, 1H), 7.56-7.49 (m, 5H), 7.38 (t, J = 7.6 Hz, 2H), 7.23 (t, J = 8.0 Hz, 1H), 7.10 (s, 1H), 2.81 (s,
2H), 2.70 (s, 2H), 1.87-1.84 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 137.4, 136.1,
133.5, 131.7, 129.4, 129.0, 128.4, 127.7, 127.7, 127.0, 126.8, 126.0, 125.4, 124.0, 123.6, 122.2,
117.8, 117.4, 23.7, 23.6, 23.5, 23.3. HRMS (ESI) m/z calcd for C24H22N+ [M+H]+ 324.1747,
found 324.1756.
1-cyclohexyl-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4an). Yellow solid (31.3 mg, yield
56%, petroleum ether), mp 78-79 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.45 (d, J = 7.9 Hz, 2H),
7.33 (t, J = 7.5 Hz, 2H), 7.16 (t, J = 7.3 Hz, 1H), 6.85 (s, 1H), 3.80-3.72 (m, 1H), 2.72 (t, J = 5.7
Hz, 2H), 2.61 (t, J = 6.0 Hz, 2H), 2.06 (d, J = 12.0 Hz, 2H), 1.92-1.87 (m, 4H), 1.81-1.74 (m, 3H),
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1.64 (q, J = 12.0 Hz, 2H), 1.42 (q, J = 12.0 Hz, 2H), 1.26 (t, J = 14.0 Hz, 1H). 13C{1H} NMR (100
MHz, CDCl3, ppm) δ 136.7, 128.2, 126.6, 124.7, 121.8, 114.8, 112.9, 54.8, 34.3, 25.9, 25.5, 23.9,
23.4, 23.0, 22.1. HRMS (ESI) m/z calcd for C20H26N+ [M+H]+ 280.2060, found 280.2058
1-benzyl-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4ao). Yellow liquid (46.3 mg, yield 81%,
petroleum ether). 1H NMR (400 MHz, CDCl3, ppm) δ 7.46 (d, J = 7.6 Hz, 2H), 7.33 (t, J = 8.0 Hz,
5H), 7.28 (d, J = 8.8 Hz 1H), 7.17 (t, J = 7.3 Hz, 1H), 7.10 (d, J = 7.2 Hz, 2H), 5.01 (s, 2H), 2.73
(t, J = 6.0 Hz, 2H), 2.47 (t, J = 6.0 Hz, 2H), 1.84-1.80 (m, 2H), 1.78-1.74 (m, 2H). 13C{1H} NMR
(100 MHz, CDCl3, ppm) δ 138.1, 136.5, 129.1, 128.7, 128.3, 127.3, 126.7, 126.6, 124. 9, 122.2,
117.3, 115.8, 50.0, 23.7, 23.5, 22.9, 21.9. HRMS (ESI) m/z calcd for C21H22N+ [M+H]+ 288.1747,
found 288.1741.
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1-(4-methylbenzyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4ap). Yellow liquid (42.6 mg,
yield 71%, petroleum ether). 1H NMR (400 MHz, CDCl3, ppm) δ 7.45 (d, J = 7.6 Hz, 2H), 7.32 (t,
J = 7.5 Hz, 2H), 7.17-7.12 (m, 3H), 7.00 (d, J = 7.8 Hz, 2H), 6.78 (s, 1H), 4.95 (s, 2H), 2.72 (t, J =
6.0 Hz, 2H), 2.48 (t, J = 6.2 Hz, 2H), 2.33 (s, 3H), 1.85-1.81 (m, 2H), 1.77-1.72 (m, 2H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 137.0, 136.6, 135.0, 129.3, 129.1, 128.3, 126.8, 126.6, 124.8,
122.2, 117.2, 115.8, 49.8, 23.7, 23.5, 22.9, 22.0, 21.0. HRMS (ESI) m/z calcd for C22H24N+
[M+H]+ 302.1903, found 302.1904.
1-(4-methoxybenzyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4aq). Yellow liquid (33.8
mg, yield 53%, petroleum ether/ethyl acetate = 20:1). 1H NMR (400 MHz, CDCl3, ppm) δ 7.45 (d,
J = 7.2 Hz, 2H), 7.33 (t, J = 7.7 Hz, 2H), 7.16 (t, J = 7.3 Hz, 1H), 7.06 (d, J = 8.6 Hz, 2H), 6.86 (d,
J = 8.6 Hz, 2H), 6.77 (s, 1H), 4.93 (s, 2H), 3.80 (s, 3H), 2.72 (t, J = 5.9 Hz, 2H), 2.50 (t, J = 6.0 Hz,
2H), 1.87-1.81 (m, 2H), 1.78-1.72 (m, 2H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 158.9,
136.6, 130.0, 129.0, 128.3, 128.1, 126.6, 124.8, 122.1, 117.1, 115.8, 114.0, 55.2, 49.5, 23.7, 23.5,
22.9, 22.0. HRMS (ESI) m/z calcd for C22H24NO+ [M+H]+ 318.1853, found 318.1855.
1-(4-chlorobenzyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4ar). Yellow liquid (52.7 mg,
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yield 82%, petroleum ether). H NMR (400 MHz, CDCl3, ppm) δ 7.45 (d, J = 7.4 Hz, 2H),
7.35-7.27 (m, 4H), 7.17 (t, J = 7.3 Hz, 1H), 7.01 (d, J = 8.2 Hz, 2H), 6.77 (s, 1H), 4.96 (s, 2H),
2.72 (t, J = 6.0 Hz, 2H), 2.44 (t, J = 6.2 Hz, 2H), 1.85-1.79 (m, 2H), 1.77-1.72 (m, 2H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 136.7, 136.3, 133.1, 128.8, 128.5, 128.3, 128.0, 126.6, 125.0,
122.5, 117.2, 116.1, 49.4, 23.7, 23.5, 22.9, 21.9. HRMS (ESI) m/z calcd for C21H21ClN+ [M+H]+
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322.1357, found 322.1358.
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1-(3-methylbenzyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4as). Yellow liquid (37.0 mg,
yield 62%, petroleum ether). 1H NMR (400 MHz, CDCl3, ppm) δ 7.46 (d, J = 7.2 Hz, 2H), 7.33 (t,
J = 7.7 Hz, 2H), 7.23 (t, J = 7.6 Hz, 1H), 7.16 (t, J = 7.3 Hz, 1H), 7.09 (d, J = 7.6 Hz, 1H), 6.96 (s,
1H), 6.90 (d, J = 7.6 Hz, 1H), 6.79 (s, 1H), 4.96 (s, 2H), 2.73 (t, J = 5.9 Hz, 2H), 2.50 (t, J = 6.0
Hz, 2H), 2.34 (s, 3H), 1.86-1.81 (m, 2H), 1.79-1.73 (m, 2H). 13C{1H} NMR (100 MHz, CDCl3,
ppm) δ 138.3, 138.0, 136.6, 129.1, 128.6, 128.3, 128.1, 127.5, 126.6, 124.8, 123.9, 122.2, 117.3,
115.7, 50.0, 23.7, 23.5, 22.9, 22.0, 21.4. HRMS (ESI) m/z calcd for C22H24N+ [M+H]+ 302.1903,
found 302.1904.
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1-(2-methylbenzyl)-3-phenyl-4,5,6,7-tetrahydro-1H-indole (4at). Yellow liquid (34.7 mg,
yield 58%, petroleum ether). 1H NMR (400 MHz, CDCl3, ppm) δ 7.45 (d, J = 7.2 Hz, 2H), 7.32 (t,
J = 7.7 Hz, 2H), 7.20-7.13 (m, 4H), 6.71 (d, J = 5.3 Hz, 2H), 4.95 (s, 2H), 2.75 (t, J = 5.9 Hz, 2H),
2.48 (t, J = 5.9 Hz, 2H), 2.33 (s, 3H), 1.87-1.82 (m, 2H), 1.80-1.75 (m, 2H). 13C{1H} NMR (100
MHz, CDCl3, ppm) δ 136.6, 136.1, 135.1, 130.1, 129.3, 128.3, 127.3, 126.9, 126.6, 126.4, 124.8,
122.2, 117.2, 115.7, 47.9, 23.8, 23.6, 22.9, 21.9, 19.0. HRMS (ESI) m/z calcd for C22H24N+
[M+H]+ 302.1903, found 302.1904.
1-phenyl-3-(p-tolyl)-4,5,6,7-tetrahydro-1H-indole (5a). Yellow solid (40.1 mg, yield 70%,
petroleum ether), mp 104-105 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.46-7.35 (m, 7H), 7.31 (t,
J = 8.0 Hz, 1H), 7.19 (d, J = 7.9 Hz, 2H), 2.77 (t, J = 6.0 Hz, 2H), 2.63 (t, J = 5.7 Hz, 2H), 2.37 (s,
3H), 1.84-1.81 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 139.9, 134.9, 133.1, 129.1,
129.1, 129.0, 126.9, 126.2, 124.6, 123.7, 117.3, 117.1, 23.6, 23.5, 23.4, 23.2, 21.1. HRMS (ESI)
m/z calcd for C21H22N+ [M+H]+ 288.1747, found 288.1745.
3-(4-methoxyphenyl)-1-phenyl-4,5,6,7-tetrahydro-1H-indole (5b). Yellow solid (43.4 mg,
yield 72%, petroleum ether), mp 118-120 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.44 (t, J = 8.6
Hz, 4H), 7.36 (d, J = 7.5 Hz, 2H), 7.31 (t, J = 7.3 Hz, 1H), 6.93 (t, J = 4.0 Hz, 3H), 3.84 (s, 3H),
2.75 (t, J = 6.0 Hz, 2H), 2.63 (t, J = 6.0 Hz, 2H), 1.84-1.81 (m, 4H). 13C{1H} NMR (100 MHz,
CDCl3, ppm) δ 157.5, 139.9, 129.1, 128.9, 128.6, 128.0, 126.1, 124.5, 123.4, 117.0, 116.9, 113.8,
55.2, 23.6, 23.5, 23.4, 23.2. HRMS (ESI) m/z calcd for C21H22NO+ [M+H]+ 304.1696, found
304.1698.
3-(4-chlorophenyl)-1-phenyl-4,5,6,7-tetrahydro-1H-indole (5c). Yellow solid (42.3 mg,
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yield 69%, petroleum ether), mp 100-101 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.47-7.42 (m,
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4H), 7.36-7.32 (m, 5H), 6.98 (s, 1H), 2.75 (s, 2H), 2.62 (s, 2H), 1.86-1.81 (m, 4H). 13C{1H} NMR
(100 MHz, CDCl3, ppm) δ 139.7, 134.6, 130.8, 129.4, 129.1, 128.5, 128.0, 126.4, 124.6, 122.5,
117.6, 116.9, 23.5, 23.4, 23.4, 23.1. HRMS (ESI) m/z calcd for C20H19ClN+ [M+H]+ 308.1201,
found 308.1203.
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3-(4-bromophenyl)-1-phenyl-4,5,6,7-tetrahydro-1H-indole (5d). Yellow solid (51.3 mg,
yield 73%, petroleum ether), mp 81-83 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.50-7.41 (m, 4H),
7.37-7.31 (m, 5H), 6.98 (s, 1H), 2.74 (t, J = 6.0 Hz, 2H), 2.60 (t, J = 6.0 Hz, 2H), 1.84-1.81 (m,
4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 139.7, 135.0, 131.4, 129.5, 129.1, 128.4, 126.5,
124.6, 122.5, 118.9, 117.6, 116.9, 23.5, 23.5, 23.4, 23.1. HRMS (ESI) m/z calcd for C20H19BrN+
[M+H]+ 352.0695, found 352.0697.
3-(4-nitrophenyl)-1-phenyl-4,5,6,7-tetrahydro-1H-indole (5e). Yellow solid (32.8 mg,
yield 52%, petroleum ether), mp 148-150 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 8.21 (d, J = 8.7
Hz, 2H), 7.62 (d, J = 8.7 Hz, 2H), 7.47 (t, J = 7.6 Hz, 2H), 7.36 (t, J = 8.0 Hz, 2H), 7.13 (s, 1H),
2.81 (t, J = 6.0 Hz, 2H), 2.59 (t, J = 6.0 Hz, 2H), 1.86-1.83 (m, 4H). 13C{1H} NMR (100 MHz,
CDCl3, ppm) δ 145.0, 143.4, 139.3, 130.5, 129.3, 127.1, 126.4, 124.8, 124.1, 121.6, 119.4, 117.2,
+
23.8, 23.4, 23.4, 22.9. HRMS (ESI) m/z calcd for C20H19N2O2 [M+H]+ 319.1441, found
319.1441.
3-(2-chlorophenyl)-1-phenyl-4,5,6,7-tetrahydro-1H-indole (5f). Yellow liquid (46.1 mg,
yield 75%, petroleum ether). 1H NMR (400 MHz, CDCl3, ppm) δ 7.46-7.40 (m, 4H), 7.36 (d, J =
7.9 Hz, 2H), 7.29 (t, J = 8.0 Hz, 1H), 7.24 (d, J = 7.4 Hz, 1H), 7.17 (t, J = 7.6 Hz, 1H), 7.00 (s,
1H), 2.64 (t, J = 5.6 Hz, 2H), 2.58 (t, J = 5.6 Hz, 2H), 1.83-1.77 (m, 4H). 13C{1H} NMR (100
MHz, CDCl3, ppm) δ 139.8, 134.7, 133.0, 131.6, 129.8, 129.0, 128.0, 127.1, 126.3, 126.2, 124.5,
120.6, 119.8, 118.5, 23.5, 23.4, 23.3, 22.9. HRMS (ESI) m/z calcd for C20H19ClN+ [M+H]+
308.1201, found 308.1203.
2-methyl-1,3-diphenyl-4,5,6,7-tetrahydro-1H-indole (5g). Yellow solid (29.2 mg, yield
51%, petroleum ether), mp 86-88 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.48 (t, J = 7.5 Hz, 2H),
7.40 (d, J = 4.5 Hz, 5H), 7.31 (d, J = 7.6 Hz, 2H), 7.24 (t, J = 8.0, 1H), 2.62 (t, J = 5.2 Hz, 2H),
2.41 (t, J = 5.1 Hz, 2H), 2.15 (s, 3H), 1.82-1.77 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm)
δ 138.5, 136.5, 129.4, 129.0, 128.0, 128.0, 127.8, 127.3, 125.1, 124.8, 120.2, 115.8, 23.9, 23.4,
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22.9, 22.7, 11.5. HRMS (ESI) m/z calcd for C21H22N+ [M+H]+ 288.1747, found 288.1745.
3-(naphthalen-2-yl)-1-phenyl-4,5,6,7-tetrahydro-1H-indole (5h). Yellow solid (45.1 mg,
yield 70%, petroleum ether), mp 94-96 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.93 (s, 1H), 7.83
(t, J = 6.4 Hz, 3H), 7.68 (d, J = 8.5 Hz, 1H), 7.46 (t, J = 7.5 Hz, 4H), 7.40 (t, J = 6.4 Hz, 3H), 7.34
(t, J = 7.3 Hz, 1H), 2.90 (s, 2H), 2.66 (s, 2H), 1.88-1.86 (m, 4H). 13C{1H} NMR (100 MHz,
CDCl3, ppm) δ 139.8, 133.8, 133.6, 131.6, 129.4, 129.1, 127.9, 127.7, 127.6, 126.4, 126.2, 125.9,
124.9, 124.7, 124.5, 123.6, 118.1, 117.3, 23.7, 23.6, 23.6, 23.2. HRMS (ESI) m/z calcd for
C24H22N+ [M+H]+ 324.1747, found 324.1747.
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1-phenyl-3-(thiophen-2-yl)-4,5,6,7-tetrahydro-1H-indole (5i). Yellow liquid (45.1 mg,
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yield 72%, petroleum ether). H NMR (400 MHz, CDCl3, ppm) δ 7.45 (t, J = 7.7 Hz, 2H),
7.36-7.31 (m, 3H), 7.14 (d, J = 4.9 Hz, 1H), 7.06 (d, J = 7.7 Hz, 3H), 2.79 (t, J = 6.1 Hz, 2H), 2.60
(t, J = 4.0 Hz, 2H), 1.89-1.79 (m, 4H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 139.6, 138.6,
129.3, 129.1, 127.3, 126.4, 124.5, 121.8, 121.8, 117.4, 117.2, 117.0, 23.5, 23.3, 23.2, 23.1. HRMS
(ESI) m/z calcd for C18H18NS+ [M+H]+ 280.1155, found 280.1156.
1,3-diphenyl-1H-indole (6a, CAS: 20538-11-8)[23]. Yellow solid (35.5 mg, yield 66%,
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petroleum ether), mp 102-104 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.99 (d, J = 8.4 Hz, 1H),
7.72 (d, J = 7.4 Hz, 2H), 7.61 (d, J = 7.5 Hz, 1H), 7.55 (d, J = 6.5 Hz, 4H), 7.51 (s, 1H), 7.47 (t, J
= 7.7 Hz, 2H), 7.41–7.36 (m, 1H), 7.34–7.24 (m, 3H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ
139.4, 136.6, 135.0, 129.6, 128.8, 127.6, 127.1, 126.6, 126.2, 125.5, 124.4, 122.8, 120.8, 120.1,
119.0, 110.8.
5-methyl-1,3-diphenyl-1H-indole (6b). Yellow solid (35.7 mg, yield 63%, petroleum ether),
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mp 104-106 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.78 (s, 1H), 7.72 (d, J = 7.7 Hz, 2H),
7.57–7.46 (m, 8H), 7.39-7.31 (m, 2H), 7.11 (d, J = 8.3 Hz, 1H), 2.51 (s, 3H). 13C{1H} NMR (100
MHz, CDCl3, ppm) δ 139.6, 135.2, 134.9, 130.2, 129.6, 128.8, 127.6, 127.3, 126.4, 126.1, 125.5,
124.3, 124.2, 119.7, 118.6, 110.5, 21.5. HRMS (ESI) m/z calcd for C21H18N+ [M+H]+ 284.1434,
found 284.1436
5-(tert-butyl)-1,3-diphenyl-1H-indole (6c). White solid (48.8 mg, yield 75%, petroleum
ether), mp 168-171 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.98 (s, 1H), 7.73 (d, J = 7.7 Hz, 2H),
7.59–7.49(m, 8H), 7.40-7.33 (m, 3H), 1.43 (s, 9H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ
143.9, 139.6, 135.3, 134.7, 129.6, 128.8, 127.6, 126.9, 126.4, 126.1, 125.6, 124.1, 121.0, 119.2,
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115.7, 110.4, 34.7, 31.9. HRMS (ESI) m/z calcd for C24H24N+ [M+H]+ 326.1903, found 326.1905.
1,3,5-triphenyl-1H-indole (6d). Yellow solid (40.2 mg, yield 58%, petroleum ether), mp
112-114 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 8.18 (s, 1H), 7.75 (d, J = 7.5 Hz, 2H), 7.68 (d, J
= 8.3 Hz, 3H), 7.61–7.45 (m, 10H), 7.41 (t, J = 6.7 Hz, 1H), 7.35 (t, J = 7.3 Hz, 2H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 142.3, 139.4, 136.0, 134. 9, 134.5, 129.7, 128.9, 128.7, 127.7,
127.6, 127.5, 126.7, 126.5, 126.3, 126.1, 124.3, 122.6, 119.4, 118.6, 111.1. HRMS (ESI) m/z
calcd for C26H20N+ [M+H]+ 346.1590, found 346.1592.
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3-phenyl-1-(p-tolyl)-1H-indole (6e). Yellow liquid (33.9 mg, yield 60%, petroleum ether).
1H NMR (400 MHz, CDCl3, ppm) δ 7.99 (d, J = 7.7 Hz, 1H), 7.72 (d, J = 7.7 Hz, 2H), 7.57 (d, J =
7.7 Hz, 1H), 7.46 (dd, J = 15.9, 7.4 Hz, 5H), 7.35–7.29 (m, 3H), 7.25 (t, J = 6.0 Hz, 2H), 2.45 (s,
3H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 136.9, 136.7, 136.5, 135.1, 130.2, 128.8, 127.5,
126.9, 126.1, 125.6, 124.4, 122.6, 120.7, 120.0, 118.7, 110.8, 21.1. HRMS (ESI) m/z calcd for
C21H18N+ [M+H]+ 284.1434, found 284.1436.
1-(4-methoxyphenyl)-3-phenyl-1H-indole (6f, CAS: 1423744-14-2)[24]. Yellow liquid (31.3
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mg, yield 52%, petroleum ether). H NMR (400 MHz, CDCl3, ppm) δ 7.99 (d, J = 8.0 Hz, 1H),
7.72 (d, J = 7.6 Hz, 2H), 7.51–7.44 (m, 6H), 7.33-7.21 (m, 3H), 7.05 (d, J = 8.6 Hz, 2H), 3.89 (s,
3H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 158.3, 137.0, 135.2, 132.4, 128.8, 127.5, 126.6,
126.0, 126.0, 125.9, 122.6, 120.6, 120.0, 118.4, 114.7, 110.7, 55.5.
1-(4-chlorophenyl)-3-phenyl-1H-indole (6g). Yellow solid (42.5 mg, yield 70%, petroleum
ether), mp 95-97 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.99 (d, J = 7.8 Hz, 1H), 7.71 (d, J = 7.8
Hz, 2H), 7.56 (d, J = 7.8 Hz, 1H), 7.51-7.46 (m, 7H), 7.35–7.28 (m, 3H). 13C{1H} NMR (100
MHz, CDCl3, ppm) δ 138.0, 136.4, 134.7, 132.1, 129.8, 128.8, 127.6, 127.1, 126.4, 125.5, 125.1,
123.0, 121.1, 120.2, 119.5, 110.5. HRMS (ESI) m/z calcd for C20H15ClN+ [M+H]+ 304.0888,
found 304.0884.
1-phenyl-3-(p-tolyl)-1H-indole (6h)[25]. Yellow liquid (28.5 mg, yield 50%, petroleum
ether). 1H NMR (400 MHz, CDCl3, ppm) δ 7.98 (d, J = 7.5 Hz, 1H), 7.61 (d, J = 7.7 Hz, 3H), 7.54
(q, J = 8.0 Hz, 4H), 7.48 (s, 1H), 7.37 (t, J = 6.4 Hz, 1H), 7.30-7.22 (m, 4H), 2.42 (s, 1H). 13C{1H}
NMR (100 MHz, CDCl3, ppm) δ 139.5, 136.5, 135.8, 132.0, 129.6, 129.5, 127.5, 127.1, 126.5,
125.2, 124.4, 122.7, 120.7, 120.1, 119.0, 110.7, 21.2.
3-(4-methoxyphenyl)-1-phenyl-1H-indole (6i, CAS: 1379825-88-3)[25]. Yellow solid (34.8
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mg, yield 58%, petroleum ether), mp 83-86 °C. H NMR (400 MHz, CDCl3, ppm) δ 7.95 (d, J =
5
6
7
8
7.6 Hz, 1H), 7.62 (t, J = 8.6 Hz, 3H), 7.54 (q, J = 8.0 Hz, 4H), 7.45 (s, 1H), 7.40–7.35 (m, 1H),
7.29–7.22 (m, 2H), 7.03 (d, J = 8.5 Hz, 2H), 3.87 (s, 3H). 13C{1H} NMR (100 MHz, CDCl3, ppm)
δ 158.2, 139.5, 136.4, 129.6, 128.7, 127.5, 127.2, 126.5, 124.9, 124.3, 122.7, 120.7, 120.0, 118.7,
114.3, 110.7, 55.3.
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3-(4-bromophenyl)-1-phenyl-1H-indole (6j, CAS: 1379825-86-1)[25]. Yellow solid (41.9
mg, yield 60%, petroleum ether), mp 120-123 °C. 1H NMR (400 MHz, CDCl3, ppm) δ 7.93 (d, J =
7.7 Hz, 1H), 7.59 (s, 5H), 7.55 (d, J = 4.3 Hz, 4H), 7.51 (s, 1H), 7.42-7.38 (m, 1H), 7.32–7.26 (m,
2H). 13C{1H} NMR (100 MHz, CDCl3, ppm) δ 139.3, 136.6, 134.0, 131.9, 129.7, 129.0, 126.8,
126.7, 125.6, 124.5, 122.9, 121.0, 119.8, 117.8, 110.9.
■ ASSOCIATED CONTENT
Supporting Information
This material is available free of charge via the Internet at http://pubs.acs.org.
1H and 13C NMR spectra for the products.
■ AUTHOR INFORMATION
Corresponding Author
*E-mail: fhxiao@xtu.edu.cn.
*E-mail: gjdeng@xtu.edu.cn.
■ ACKNOWLEDGMENT
This work was supported by the National Natural Science Foundation of China (21572194,
21871226, 21502160), the Collaborative Innovation Center of New Chemical Technologies for
Environmental Benignity and Efficient Resource Utilization, the Hunan Provincial Innovative
Foundation for Postgraduate (CX2018B046).
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