An efficient synthesis of ring-fused indoles via copper-catalyzed tandem reaction of N-(o-alkynylphenyl)imines

Article abstract of DOI:10.1002/aoc.1648

A copper-catalyzed tandem intramolecular cyclization-addition reaction of N-(o-alkynylphenyl)imines is disclosed. This strateg offers a simple and promising method for accessing ring-fused indoles.

Full text of DOI:10.1002/aoc.1648

Full Paper
Received: 25 October 2009
Revised: 9 February 2010
Accepted: 19 February 2010
Published online in Wiley Interscience: 29 March 2010
(www.interscience.com) DOI 10.1002/aoc.1648
An efficient synthesis of ring-fused indoles
via copper-catalyzed tandem reaction
of N-(o-alkynylphenyl)imines
Weijun Fua∗, Mei Zhua and Guanglong Zoub
Acopper-catalyzedtandemintramolecularcyclization-additionreactionofN-(o-alkynylphenyl)iminesisdisclosed. Thisstrategy
c
offers a simple and promising method for accessing ring-fused indoles. Copyright ꢀ 2010 John Wiley & Sons, Ltd.
Keywords: copper catalyst; indoles; tandem reaction; N-(o-alkynylphenyl)imines
Introduction
The indole nucleus is a prominent structural motif found in
numerous natural and unnatural products with vital biological
activities and thus considerable attention has been directed
toward general, flexible and selective methods for the synthe-
sis of highly functionalized indole derivatives.[1–5] One of the
Scheme 1. CuBr-catalyzed tandem reaction of N-(o-alkynylphenyl)imines.
most reliable approaches for the synthesis of this class of com-
pounds is the cyclization of orthoalkynylaniline derivatives by use
by a tethered nucleophile to afford ring-fused indoles in a novel
of transition metal catalysts.[6–9] For example, Yamamoto and
tandem reaction process (Scheme 1).
co-workers reported that tandem cyclization of 2-alkynylaniline
proceeded successfully to give nucleophile-incorporated indoles
in the presence of certain nucleophiles, such as allyl carbonate and
Results and Discussion
alcohol.[10–13] Hiroya developed efficient Cu(II)-catalyzed indoles
formation by cyclization of 2-ethynyl aniline derivatives.[14,15] Ma
and co-workers reported a CuI/L-proline-catalyzed domino cou-
pling–cyclization process of 2-bromotrifluoroacetanilides with
alkynes or β-keto esters for the preparation of indoles.[16,17]
Ohno and Fujii developed a copper(I)-catalyzed domino three-
component coupling–cyclization reaction for the synthesis of
2-(aminomethyl)indoles.[18–20] Other approaches include Fischer
synthesis,[21,22] Reissert synthesis,[23] Madelung synthesis,[24] Cas-
tro synthesis,[25] etc. However, these methods might suffer from
the limited availability of the starting materials, harsh conditions
or expensive catalysts. Therefore, more efficient and facile routes
to these useful molecules under mild conditions are needed.
Previous investigations have shown that Cu(I) catalysts display
considerable catalytic activity under moderate conditions.[26–29]
Recently, the design of Cu(I)-catalyzed tandem nucleophilic ad-
ditions that preserve atomeconomy in a one-pot reaction has
attracted attention becasue of the application to efficient con-
struction of molecular structures.[30–34] In the context of on-
going efforts to develop cascade reactions for the synthesis of
heterocycles,[35] we recently reported the electrophilic cyclization
of 1-(1-alkynyl)-cyclopropyl ketones using I+ or PhSe+ as elec-
trophilic species to afford an efficient synthesis of substituted
halofurans and chalcogenylfurans.[36] Herein, we report a concep-
tually new synthetic approach to ring-fused indoles utilizing the
copper-catalyzed domino reaction of N-(o-alkynylphenyl)imines.
In this simple one-pot assembly, N-(o-alkynylphenyl)imines might
cyclize via the formation of an iminium ion, which is trapped
We first examined the reaction of 3-[2-(diphenylmethylene-
amino)phenyl]prop- 2-yn-1-ol 1a with various Cu(I) salts to check
their catalytic activity for the formation of ring-fused indoles 2a.
The reaction of 3-[2-(diphenylmethyleneamino)phenyl]prop- 2-
yn-1-ol 1a at 80 ◦C in the absence of any catalyst did not yield
any desired product (entry 1, Table 1). As anticipated, the use
of a copper(I) catalyst such as CuI gave the desired product 2a,
albeit in 37% yield (entry 2, Table 1). Surprisingly, when CuBr was
employed as a catalyst, the desired product 2a was isolated in
81% yield (entry 3, Table 1). In contrast, the employment of other
copper(I)catalystssuchasCuCl, CuCl(PPh3)andCuCN, underthese
conditions resulted in low yields, and the reactions were generally
much more sluggish.
Next we investigated the annulation reaction of various
N-(o-propynolphenyl)imines 1. The results, summarized in Table 2,
prove that this sequential reaction indeed provides a straightfor-
ward entry to a variety of fused tricyclic compounds with an
indole unit in good to high yields. The substituent on the aromatic
∗
Correspondenceto:Weijun Fu,CollegeofChemistryandChemicalEngineering,
Luoyang Normal University, Luoyang 471022, China. E-mail: wjfu@lynu.edu.cn
a
College of Chemistry and Chemical Engineering, Luoyang Normal University,
Luoyang 471022, People’s Republic of China
b
School of Chemistry and Environmental Science, Guizhou University for
Nationalities, Guiyang 550025, People’s Republic of China
c
Appl. Organometal. Chem. 2010, 24, 499–502
Copyright ꢀ 2010 John Wiley & Sons, Ltd.

W. Fu and G. Zou
Table 1. Effect of various Cu(I) salts on the reaction of 1a to give 2aa
Scheme 2. Plausible mechanism for the cyclization of N-(o-
alkynylphenyl)imines.
The proposed reaction mechanism is shown in Scheme 2. The
intramolecular addition of the nitrogen atom of the imine to the
copper-coordinated alkynes[37,38] might result in the formation
of the intermediate iminium ion 3, which upon subsequent
trappingwithatetherednucleophilefollowedbyprotonationwith
regeneration of the Cu(I) catalyst produces the final product 2.
Entry
Catalyst
Time
Yields (%)b
1
2
3
4
5
6
None
CuI
12 h
12 h
6 h
0
37
CuBr
81
CuCl
12 h
12 h
12 h
45
CuCl(PPh3)
CuCN
Trace
34
a All of the reactions were carried out using 1a (0.5 mmol) in DMF (2 ml)
at 80 ◦C for the specified time.
Conclusions
b Isolated yields.
In conclusion, we have developed a CuBr-catalyzed domino
reaction of N-(o-alkynylphenyl)imines that provides an efficient
route to ring-fused indoles under mild conditions. The cascade
cyclization has some advantages such as mild reaction conditions,
simple procedure and good yields. Further studies to elucidate
the precise mechanism of this reaction and to extend the scope of
synthetic utility are in progress in our laboratory.
Table 2. CuBr-catalyzed tandem cyclization of 1a
Experimental
General Synthetic Procedure
Entry
R1, R2
R3
n
Yields (%)b
All experiments were operated according to the following general
procedure: to a mixture of N-(o-alkynylphenyl)imines 1 (0.5 mmol)
and Cu(I)Br (0.05 mmol) was added DMF (2 ml) and the resulting
solution was stirred until the disappearance of starting material
on TLC at 80 ◦C. Water (20 ml) was added and the product was
extracted with ethyl acetate. The extracts were washed with
water and dried over anhydrous sodium sulfate. The solvent was
removed, and the residue was then filtered through a short silica
gel column with hexane–EtOAc as eluent to give pure product 2.
The analytical data to these products are shown below.
1
C6H5, C6H5
4-FC6H4, 4-FC6H4
C6H5, 4-ClC6H4
C6H5, 4-MeOC6H4
C6H5, C6H5
H
H
1
1
1
1
1
1
1
2
2
2
2
2
2
2
3
3
2a, 81
2b, 78
2c, 85
2d, 87
2e, 72
2f, 71
2g, 78
2h, 89
2i, 79
2
3
H
4
H
5
CH3
CH3
CH3
H
6
4-MeOC6H4, 4-MeOC6H4
C6H5, 4-ClC6H4
C6H5, C6H5
7
8
9
4-FC6H4, 4-FC6H4
C6H5, 4-ClC6H4
C6H5, C6H5
H
10
11
12
13
14
15
16
H
2j, 74
CH3
CH3
CH3
CH3
H
2k, 78
2l, 69
1,3-Dihydro-3,3-diphenyloxazolo[3,4-a]indole (2a)
4-MeOC6H4, 4-MeOC6H4
C6H5, 4-ClC6H4
4-FC6H4, 4-FC6H4
C6H5, C6H5
1H NMR (400M, CDCl3): 7.59–7.63 (m, 1H, ArH), 7.36–7.41 (m,
10H, ArH), 6.99–7.10 (m, 2H, ArH), 6.86–6.88 (m, 1H, ArH), 6.30 (s,
1H, CH–), 5.18 (s, 2H, –CH2 –O); 13C NMR (100M, CDCl3): 140.3
(indole–C), 139.8, 133.9, 132.0, 129.2, 128.4, 128.1, 121.4, 121.2,
120.0, 110.5 (Ar–C), 98.1(N–C–O), 91.5 (indole–C), 65.4 (CH2). IR
(KBr): 2915, 1626, 1602, 1503, 1445, 1279, 1149; HRMS: calcd for
C22H17NO: 311.1310. Found: 311.1302.
2m, 82
2n, 77
2o, 80
2p, 70
C6H5, 4-ClC6H4
H
a All of the reaction was carried out using 1 (0.5 mmol) in DMF (2 ml) at
80 ◦C.
b Isolated yields.
3,3-Bis(4-fluorophenyl)-1,3-dihydrooxazolo[3,4-a]indole (2b)
ring of R1 and R2 does not affect the efficiency of the reac-
tion. For imines 1 having an electron-withdrawing group or an
electron-donating group on the benzene ring, these reactions pro-
ceeded smoothly to give the corresponding cyclization products.
This transformation can be successfully extended to a variety of
N-(o-hydroxyalkynylphenyl)imines 1 leading to the generation of
the corresponding ring-fused indoles in 69–93% yields (Table 2,
entries 8–16).
1H NMR (400M, CDCl3): 7.59 (d, J = 7.6 Hz, 1H, ArH), 7.28–7.33
(m, 4H, ArH), 6.97–7.10 (m, 6H, ArH), 6.78 (d, J = 8 Hz, 1H, ArH),
6.27 (s, 1H, CH–), 5.11 (s, 2H, –CH2 –O); 13C NMR (100M, CDCl3):
164.5, 162.1(Ar–C), 140.0 (indole–C), 135.6 (d, J = 2.9 Hz), 133.9,
131.8, 130.0 (d, J = 8.4 Hz), 121.6 (d, J = 27.3 Hz), 120.2, 115.4 (d,
J = 22.1 Hz), 110.2 (Ar–C), 97.2 (N–C–O), 91.9 (indole–C), 65.3
(CH2). IR (KBr): 2914, 1619, 1600, 1509, 1485, 1450, 1184; HRMS:
calcd for C22H15F2NO: 347.1122. Found: 347.1128.
c
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Copyright ꢀ 2010 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2010, 24, 499–502

Synthesis of ring-fused indoles
3-(4-Chlorophenyl)-1,3-dihydro-3-phenyloxazolo[3,4-a]indole (2c)
140.8 (indole–C), 137.7, 136.2, 134.7, 132.4, 130.1, 128.9, 128.2,
120.6, 119.7, 112.8 (Ar–C), 99.5 (N–C–O), 94.2 (indole–C), 59.5
(–OCH2), 24.4 (–CH2); IR (KBr): 2927, 2886, 1632, 1605, 1496, 1195,
1148, 1021; HRMS: calcd for C23H19NO: 325.1467. Found: 325.1462.
1H NMR (400M, CDCl3): 7.58 (d, J = 8 Hz, 1H, ArH), 7.24–7.37
(m, 9H, ArH), 7.07 (t, J = 7.6 Hz, 1H, ArH), 6.98 (t, J = 7.2 Hz,
1H, ArH), 6.80 (d, J = 8 Hz, 1H, ArH), 6.23 (s, 1H, CH–), 5.13
(s, 2H, –CH2 –O); 13C NMR (100M, CDCl3): 140.1(indole–C), 139.2,
138.5, 135.3, 134.0, 131.9, 129.5, 129.4, 128.6, 128.5, 127.9, 121.6,
121.3, 120.1, 110.3 (Ar–C), 97.6 (N–C–O), 91.8 (indole–C), 65.4
(CH2). IR (KBr): 1624, 1604, 1503, 1450, 1226, 1159; HRMS: calcd for
C22H16ClNO: 345.0920. Found: 345.0929.
1,1-Bis(4-fluorophenyl)-3,4-dihydro-1H-[1,3]oxazino[3,4-a]indole
(2i)
1H NMR (400M, CDCl3): 7.50 (d, J = 7.6 Hz, 1H, ArH), 7.16–7.26
(m, 4H, ArH), 7.00–7.05 (m, 5H, ArH), 6.77–6.80 (m, 1H, ArH), 6.42
(s, 1H, CH–), 6.28 (t, J = 4 Hz, 1H, ArH), 3.90 (t, J = 5.6 Hz,
2H, –OCH2), 3.26 (t, J = 5.6 Hz, 2H, –CH2). 13C NMR (100M,
CDCl3): 164.4, 161.9 (Ar–C), 136.7 (indole–C), 136.0, 134.6, 130.8
(d, J = 9.2 Hz), 128.3, 121.0, 120.0, 115.3 (d, J = 21.1 Hz), 112.6
(Ar–C), 99.9 (N–C–O), 93.5 (indole–C), 59.7 (–OCH2), 24.4 (–CH2).
IR (KBr): 2921, 1617, 1607, 1512, 1480, 1184, 1016; HRMS: calcd for
C23H17F2NO: 361.1278. Found: 361.1287.
1,3-Dihydro-3-(4-methoxyphenyl)-3-phenyloxazolo[3,4-a]indole
(2d)
1H NMR (400M, CDCl3): 7.60–7.65 (m, 1H, ArH), 7.24–7.38 (m,
6H, ArH), 7.10–7.13 (m, 1H, ArH), 6.79–6.83 (m, 5H, ArH), 6.29 (s,
1H, CH–), 5.18 (s, 2H, –CH2 –O), 3.77 (s, 3H, OCH3). 13C NMR
(100M, CDCl3): 159.8 (Ar–C), 140.5 (indole–C), 137.2, 134.6, 132.2,
131.0, 129.1, 126.3, 125.8, 124.3, 123.0, 121.2, 120.8, 117.4, 112.6
(Ar–C), 98.7 (N–C–O), 92.1 (indole–C), 65.2 (CH2), 55.4 (OCH3); IR
(KBr): 2951, 2915, 1624, 1598, 1501, 1450, 1172; HRMS: calcd for
C23H19NO2: 341.1416. Found: 341.1418.
1-(4-Chlorophenyl)-3,4-dihydro-1-phenyl-1H-[1,3]oxazino[3,4-
a]indole (2j)
1H NMR (400M, CDCl3): 7.51 (d, J = 7.2 Hz, 1H, ArH), 7.25–7.34
(m, 5H, ArH), 7.15–7.21 (m, 4H, ArH), 6.97 (t, J = 8 Hz, 1H, ArH),
6.38 (s, 1H, CH–), 6.27 (t, J = 8 Hz, 1H, ArH), 3.87 (t, J = 6 Hz,
2H, –OCH2), 3.22 (t, J = 6 Hz, 2H, –CH2). 13C NMR (100M, CDCl3):
140.5 (indole–C), 139.7, 136.2, 135.1, 134.7, 130.5, 129.3, 128.9,
128.6, 128.5, 128.3, 121.0, 120.0, 112.7 (Ar–C), 99.9 (N–C–O), 93.9
(indole–C), 59.7 (–OCH2), 24.5(–CH2). IR (KBr): 2924, 1625, 1598,
1510, 1450, 1216, 1150; HRMS: calcd for C23H18ClNO: 359.1077.
Found: 359.1080.
1,3-Dihydro-7-methyl-3,3-diphenyloxazolo[3,4-a]indole(2e)
1H NMR (400M, CDCl3): 7.32–7.39 (m, 11H, ArH), 6.83 (d, J = 8.4 Hz,
1H, ArH), 6.74 (d, J = 8.4 Hz, 1H, ArH), 6.20 (s, 1H, CH–), 5.16 (s,
2H, –CH2 –O), 2.42 (s, 3H, –CH3). 13C NMR (100M, CDCl3): 140.2
(indole–C), 139.8, 134.1, 130.2, 129.1, 129.0, 128.2, 127.9, 122.8,
120.8, 110.0(Ar–C), 97.9(N–C–O), 90.9(indole–C), 65.3(CH2), 21.4
(–CH3); IR (KBr): 2924, 2856, 1619, 1604,1501, 1489, 1455, 1184,
1015; HRMS: calcd for C23H19NO: 325.1467. Found: 325.1467.
3,4-Dihydro-7-methyl-1,1-diphenyl-1H-[1,3]oxazino[3,4-a]indole
(2k)
1,3-Dihydro-3,3-bis(4-methoxyphenyl)-7-methyloxazolo[3,4-
1H NMR (400M, CDCl3): 7.31–7.37 (m, 7H, ArH), 7.24–7.26 (m,
4H, ArH), 6.57–6.59 (m, 1H, ArH), 6.33 (s, 1H, CH–), 6.18 (d,
J = 8.8 Hz, 1H, ArH), 3.92 (t, J = 6 Hz, 2H, –OCH2), 3.25 (t, J = 6 Hz,
2H, –CH2), 2.36 (s, 3 H,–CH3). 13C NMR (100M, CDCl3): 145.1(Ar–C),
141.0 (indole–C), 134.9, 129.1, 129.0, 128.9, 128.3, 127.9, 122.3,
119.6, 112.5(Ar–C), 99.1(N–C–O), 94.2 (indole–C), 59.7(–OCH2),
24.5(–CH2), 21.4(–CH3); IR (KBr): 2924, 2856, 1620, 1606, 1510,
1448, 1219, 1183; HRMS: calcd for C24H21NO: 339.1623. Found:
339.1629.
a]indole (2f)
1H NMR (400M, CDCl3): 7.36 (s, 1H, ArH), 7.23–7.35 (m, 4H, ArH),
6.79–6.83 (m, 5H, ArH), 6.70 (d, J = 8 Hz, 1H, ArH), 6.15 (s,
1H, CH–), 5.09 (s, 2H, –CH2 –O), 3.78 (s, 6H, –OCH3), 2.40 (s,
3H,–CH3). 13C NMR (100M, CDCl3): 160.1 (Ar–C), 140.4 (indole–C),
134.2, 132.2, 130.3, 129.4, 129.1, 122.8, 120.9, 113.6, 110.1(Ar–C),
97.7 (N–C–O), 90.7 (indole–C), 65.1 (CH2), 55.4 (–OCH3), 21.5
(–CH3); IR (KBr): 2842, 1621, 1601, 1505, 1455, 1178, 1029; HRMS:
calcd for C25H23NO3: 385.1678. Found: 385.1668.
3,4-Dihydro-1,1-bis(4-methoxyphenyl)-7-methyl-1H-[1,3]oxazino
[3,4-a]indole (2l)
3-(4-Chlorophenyl)-1,3-dihydro-7-methyl-3-phenyloxazolo[3,4-
a]indole (2g)
1H NMR (400M, CDCl3): 7.29 (s, 1H, ArH), 7.10–7.14 (m, 4H, ArH),
6.79–6.83 (m, 4H, ArH), 6.56–6.58 (m, 1H, ArH), 6.29 (s, 1H, CH–),
6.19 (d, J = 8.4 Hz, 1H, ArH), 3.86 (t, J = 6 Hz, 2H, –OCH2), 3.76 (s,
6H,–OCH3), 3.25(t, J = 6 Hz, 2H, –CH2), 2.33 (s, 3H, –CH3). 13CNMR
(100M, CDCl3):160.0 (Ar–C), 135.0 (indole–C), 134.7, 133.4, 130.3,
128.8, 128.5, 122.3, 119.6, 113.5, 112.6 (Ar–C), 99.0 (N–C–O), 93.8
(indole–C), 59.5(–OCH2), 55.4 (–OCH3), 24.5 (–CH2), 21.4(–CH3);
IR (KBr): 2922, 2851, 1623, 1601, 1509, 1450, 1220, 1178; EIMS m/z
(%): 399 (M+, 85). HRMS: calcd for C26H25NO3: 399.1834. Found:
399.1823.
1H NMR (400M, CDCl3): 7.36 (s, 1H, ArH), 7.26–7.34 (m, 9H, ArH),
6.80 (d, J = 8.4 Hz, 1H, ArH), 6.70 (d, J = 8.4 Hz, 1H, ArH), 6.16
(s, 1H, CH–), 5.09 (s, 2H, –CH2 –O), 2.38 (s, 3H, –CH3). 13C NMR
(100M, CDCl3): 140.2 (indole–C), 139.5, 138.7, 135.3, 134.4, 130.3,
129.6, 129.4, 129.3, 128.6, 128.5, 128.0, 123.2, 121.1, 110.0 (Ar–C),
97.6(N–C–O),91.3(indole–C),65.5(–CH2 –O),21.6(–CH3);IR(KBr):
2865, 1620, 1602, 1500, 1455, 1226, 1159, 1011; HRMS: calcd for
C23H18ClNO: 359.1077. Found: 359.1083.
3,4-Dihydro-1,1-diphenyl-1H-[1,3]oxazino[3,4-a]indole (2h)
1-(4-Chlorophenyl)-3,4-dihydro-7-methyl-1-phenyl-1H-[1,3]oxazino
[3,4-a]indole (2m)
1H NMR (400M, CDCl3): 7.80 (d, J = 7.6 Hz, 2H, ArH), 7.22–7.37 (m,
9H, ArH), 6.98 (t, J = 7.6 Hz, 1H, ArH), 6.73 (t, J = 7.6 Hz, 1H, ArH),
6.40 (s, 1H, CH–), 6.28 (d, J = 8 Hz, 1H, ArH), 3.91 (t, J = 7.6 Hz,
2H, –OCH2), 3.25 (t, J = 7.6 Hz, 2H, –CH2). 13C NMR (100M, CDCl3):
1H NMR (400M, CDCl3): 7.18–7.40 (m, 10H, ArH), 6.59–6.62 (m,
1H, ArH), 6.33 (s, 1H, CH–), 6.17 (d, J = 8.4 Hz, 1H, ArH), 3.90
c
Appl. Organometal. Chem. 2010, 24, 499–502
Copyright ꢀ 2010 John Wiley & Sons, Ltd.
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W. Fu and G. Zou
(t, J = 6 Hz, 2H, –OCH2), 3.24 (t, J = 6 Hz, 2H, –CH2), 2.36 (s, 3H, References
–CH3).13CNMR(100M,CDCl3):140.6(indole–C),139.7,135.1,134.7,
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134.5, 130.5, 129.2, 129.1, 128.9, 128.6, 128.5, 128.4, 122.5, 119.7,
112.3 (Ar–C), 99.4 (N–C–O), 93.8 (indole–C), 59.7(–OCH2), 24.5
(–CH2), 21.4 (–CH3); IR (KBr): 2925, 1630, 1608, 1508, 1452, 1216,
1167; HRMS: calcd for C24H20ClNO: 373.1233. Found: 373.1241.
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1H NMR (400M, CDCl3): 7.31 (s, 1H, ArH), 7.16–7.23 (m, 4H, ArH),
6.97–7.01 (m, 4H, ArH), 6.58–6.60 (m, 1H, ArH), 6.31 (s, 1H, CH–),
6.13 (d, J = 8.8 Hz, 1H, ArH), 3.86 (t, J = 6 Hz, 2H, –OCH2), 3.21 (t,
J = 6 Hz, 2H, –CH2), 2.34 (s, 3H, –CH3). 13C NMR (100M, CDCl3):
164.3, 161.9 (Ar–C), 136.8 (d, J = 3.1 Hz) (indole–C), 134.5 (d,
J = 16.9 Hz), 130.8 (d, J = 8.5 Hz), 129.3, 128.6, 122.6, 119.8, 115.3
(d, J = 21.2 Hz), 112.2 (Ar–C), 99.5 (N–C–O), 93.3 (indole–C),
59.7 (–OCH2), 24.5(–CH2), 21.3(–CH3); IR (KBr): 2923, 1622, 1610,
1502, 1450, 1183; EIMS m/z (%): 375 (M+, 73). HRMS: calcd for
C24H19F2NO: 375.1435. Found: 375.1446.
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1,3,4,5-Tetrahydro-1,1-diphenyl-[1,3]oxazepino[3,4-a]indole(2o)
1H NMR (400M, CDCl3): 7.73–7.77 (m, 1H, ArH), 7.20–7.39 (m,
10H, ArH), 6.98–7.07 (m, 2H, ArH), 6.70–6.72 (m, 1H, ArH), 6.35 (s,
1H, CH–), 3.85 (t, J = 6.4 Hz, 2H, –OCH2), 3.08 (t, J = 6.4 Hz,
2H,–CH2), 1.84–1.85(m, 2H,–CH2 –). 13CNMR(100M, CDCl3):140.5
(indole–C), 137.4, 134.6, 132.7, 130.1, 129.2, 128.6, 122.2, 121.4,
120.5, 111.8 (Ar–C), 100.5 (N–C–O), 96.3 (indole–C), 65.4(–OCH2),
28.3(–CH2), 26.4(–CH2 –); IR (KBr): 2920, 1632, 1605, 1500, 1452,
1268, 1150; HRMS: calcd for C24H21NO: 339.1623. Found: 339.1626.
1-(4-Chlorophenyl)-1,3,4,5-tetrahydro-1-phenyl-[1,3]oxazepino[3,4-
a]indole (2p)
1H NMR (400M, CDCl3): 7.43 (d, J = 7.6 Hz, 1H, ArH), 7.19–7.35 (m,
9H, ArH), 6.91 (t, J = 7.2 Hz, 1H, ArH), 6.65–6.69 (m, 1H, ArH), 6.37
(s, 1H, CH–), 6.05 (d, J = 8.4 Hz, 1H, ArH), 3.87 (t, J = 6.4 Hz, 2H,
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–OCH2), 3.11–3.14 (m, 2H, –CH2), 1.82–1.86 (m, 2H, –CH2 –). 13
C
NMR (100M, CDCl3): 143.4 (Ar–C), 140.2 (indole–C), 139.9, 137.9,
134.7, 130.4, 129.0, 128.4, 128.3, 120.6, 119.7, 119.6, 114.1 (Ar–C),
102.6 (N–C–O), 97.1 (indole–C), 65.4 (–OCH2), 28.3 (–CH2), 26.5
(–CH2 –); IR (KBr): 2925, 2850, 1621, 1611, 1502, 1450, 1183; HRMS:
calcd for C24H20ClNO: 373.1233. Found: 373.1240.
Acknowledgment
We are grateful to the National Natural Science Foundation of
China (project nos 20902042).
c
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Appl. Organometal. Chem. 2010, 24, 499–502