A convenient domino synthesis of 4,9-diphenyl-2,3-dihydro-1H-benzo[f] isoindole derivatives

Article abstract of DOI:10.1055/s-0030-1257908

The first examples are described of a convenient domino synthesis of 4,9-diphenyl-2,3-dihydro-1H-benzo[f]isoindole derivatives in a single operation by means of palladium-catalyzed cyclization of simple 1,6-diynes with aryl halides. Georg Thieme Verlag Stuttgart.

Full text of DOI:10.1055/s-0030-1257908

PAPER
3467
A Convenient Domino Synthesis of 4,9-Diphenyl-2,3-dihydro-1H-benzo[f]iso-
indole Derivatives
Yi-min Hu,* Xian-gang Lin, Tao Zhu, Jing Wan, Yong-jie Sun, Quan-sheng Zhao, Tao Yu
Laboratory of Functional Molecular Solids, Ministry of Education and Anhui Key Laboratory of Molecular-Based Materials,
School of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui, 241000, P. R. of China
Fax +86(553)3883517; E-mail: yiminhu@mail.ahnu.edu.cn
Received 26 May 2010; revised 21 June 2010
bis(3-phenylprop-2-yn-1-yl)benzenesulfonamide (2), 4-
Abstract: The first examples are described of a convenient domino
methyl-N,N-bis[3-(4-methylphenyl)prop-2-yn-1-yl]ben-
synthesis of 4,9-diphenyl-2,3-dihydro-1H-benzo[f]isoindole deriv-
zenesulfonamide (3), N,N-bis[3-(4-chlorophenyl)prop-2-
yn-1-yl]-4-methylbenzenesulfonamide (4), and N,N-
bis[3-(4-methoxyphenyl)prop-2-yn-1-yl]-4-methylben-
zenesulfonamide (5) with various aryl halides, which pro-
vide a direct, efficient, and economic method for the
construction of polycyclic heterocycles through both C–C
bond coupling and C–H bond activation processes.
atives in a single operation by means of palladium-catalyzed cy-
clization of simple 1,6-diynes with aryl halides.
Key words: domino reactions, cyclizations, heterocycles, polycy-
cles, isoindoles
Condensed heterocyclic compounds are playing increas-
ingly important roles as synthetic building blocks, phar-
macophores, and electroluminescent materials.1 The
intramolecular palladium-catalyzed hydroarylation of
alkynes was reported by Fujiwara in 2000.2 Soon after,
other transition-metal- and Lewis acid catalyzed domino
versions of this transformation emerged, and the method
quickly became a powerful tool for the construction of in-
doles and other heterocycles.3 These processes are usually
clean, because they generate less waste by minimizing the
need for isolation of intermediates in multistep syntheses
of complex molecular targets.4 The design of new catalyt-
ic and regioselective syntheses of p-conjugated fused
rings is therefore a continuing challenge that lies at the
forefront of synthetic chemistry.5 Recently, an effective
rhodium-catalyzed asymmetric cyclopentannulation has
been developed that leads to a formal synthesis of indolyl
rings,6 and a gold(I)-catalyzed 5-endo-dig cyclization has
been used in an enantioselective synthesis of cephalosta-
tin 1.7 A promising route has been developed for activa-
tion of C–H bonds in the preparation of indolines and
In a typical procedure, a mixture of 4-methyl-N,N-bis(3-
phenylprop-2-yn-1-yl)benzenesulfonamide (a), ethyl 4-
bromobenzoate, tributylamine, and palladium(II) acetate
was heated in N,N-dimethylformamide under argon over-
night. Standard workup procedures afforded the coupled
products in excellent regioselectivities for most 1,6-
diynes (Table 1). The temperature was crucial for this re-
action, and no domino reaction occurred at below 95 °C.
In contrast, higher reaction temperatures (above 130 °C)
led to the decomposition of the product 1a (Table 1), as
indicated by thin-layer chromatography. Among the cata-
lysts tested [chitosan-Pd, tetrakis(triphenylphosphine)pal-
ladium,
palladium(II)
chloride/triphenylphosphine,
palladium(II) acetate/triphenylphosphine, and bis(diben-
zylideneacetone)palladium/triphenylphosphine], palladi-
um(II) acetate/triphenylphosphine was the most effective.
N,N-Dimethylformamide was found to be a better solvent
than N,N-dimethylacetamide, toluene, or dioxane for this
reaction. Tributylamine was more effective than any of in-
organic base tested (potassium or cesium carbonate). The
following standard reaction conditions were therefore se-
lected for subsequent studies. The diyne (1 equiv) was
treated with the aryl halide (1.2 equiv) in the presence of
palladium(II) acetate (2 mol%), triphenylphosphine (4
mol%), and tributylamine (2 equiv) in N,N-dimethylform-
amide at 125 °C.
tetrahydroisoquinolines.8
The
palladium-catalyzed,
chemoselective, intramolecular, sp3 C–H activation of the
methyl group in 2-bromo-N-(2-methylaryl)-pyrroles can
afford 9H-pyrrolo[1,2-a]indoles;9 these molecules have
interesting biological and pharmaceutical properties, and
much effort has been made toward their synthesis.10 The
intramolecular nature of these transformations means that
the regio- and stereoselectivities are often excellent, per-
mitting the single compound to be obtained after several
bond-forming reactions.
Illustrative examples of the scope of the reaction are
shown in Table 1. Various diynes and substituted aryl ha-
lides are compatible with this palladium-catalyzed domi-
no reaction. A range of 4,9-diphenyl-2,3-dihydro-1H-
benzo[f]isoindole derivatives were readily isolated in
good-to-excellent yields, except in the case of 1i, when
aryl halides with a variety of substituents was used. Suit-
able substituents included ethoxycarbonyl, methoxycar-
bonyl, chloro, sulfonyl, oxo, naphthyl, cyano, or formacyl
groups. When substrate 1 or 2 was treated with an aryl ha-
lide, such as ethyl 4-bromobenzoate, methyl 4-bromoben-
zoate, or 1-bromonaphthalene, the reaction afforded 3,3-
Here, we report the first examples of convenient palladi-
um-catalyzed domino reactions11 of 4-methyl-N,N-bis(3-
phenylprop-2-yn-1-yl)benzenesulfonamide (1), N,N-
SYNTHESIS 2010, No. 20, pp 3467–3473
x
x.
x
x
.
2
0
1
0
Advanced online publication: 30.07.2010
DOI: 10.1055/s-0030-1257908; Art ID: F09310SS
© Georg Thieme Verlag Stuttgart · New York

3468
Y.-m. Hu et al.
PAPER
disubstituted 4,9-diphenyl-2,3-dihydro-1H-benzo[f]isoin- clic compound 5a (58%) in a relatively low yield (entry
doles 1a, 1e, 1h, and 2c, respectively, in yields of more 8), showing the existence of electronic effects on the dom-
than 84%. The yield of compound 1e was the highest ino reaction. The reaction of substrate 2 with aryl iodides
(87%; entry 5). Yields from substrate 1 were close to gave much lower yields than did aryl bromides (entries 9–
those of substrate 2. These results demonstrate the appli- 11). Interestingly, when aryl halides containing C–Cl or
cation of bromo compounds for the direct C–H function- C–F bonds on the benzene ring in addition to C–Br react-
alization of molecular scaffolds in the synthesis of the ed, the C–Br bond coupled selectively with the 1,6-diyne
benzo[f]isoindoline core.
(entries 6, 10–12).
Table 1 Palladium-Catalyzed One-Pot Cascade Reaction
Table 2 The Palladium-Catalyzed Reaction for the Formation of p-
Conjugated Fused Heterocycles
R1
R1
Pd(OAc)2, n-Bu3N
DMF, 125–130 °C
Pd(OAc)2, n-Bu3N
DMF, 125–130 °C
R1
PG
N
PG
N
R1C6H4Br
PG
N
R2
PG
N
R2C6H4X
R1
1 PG = Ts
1 PG = Ts, R1 = H
2 PG = SO2Ph
R1
2 PG = SO2Ph, R1 = H
3 PG = Ts, R1 = 4-Me
4 PG = Ts, R1 = 4-Cl
5 PG = Ts, R1 = 4-MeO
Entry Substratea R2C6H4Br
Product Yield (%)b
1
2
1
1
1
1
1
1
1
1
1
2
2
2
2
2
4-EtO2CC6H4Br
4-AcC6H4Br
4-NCC6H4Br
4-ClC6H4Br
1a
1b
1c
1d
85
73
60
62
87
82
62
84
45
83
74
85
60
82
Entry Substratea R2C6H4X
Product Yield (%)b
1
2
3
3
3
4
4
4
4
5
1
1
2
2
4-EtO2CC6H4Br
1-bromonaphthalene
4-MeO2CC6H4Br
4-EtO2CC6H4Br
1-bromonaphthalene
4-ClC6H4Br
3a
3b
3c
4a
4b
4c
4d
5a
1j
75
76
69
80
79
70
72
58
55
56
57
69
3
4
3
5
1-bromonaphthalene 1e
4
6
4-MeO2SC6H4Br
4-OHCC6H4Br
4-MeO2CC6H4Br
4-MeC6H4Br
1f
5
7
1g
1h
1i
6
8
7
4-MeO2CC6H4Br
1-bromonaphthalene
PhI
9
8
10
11
12
13
14
4-EtO2CC6H4Br
4-AcC6H4Br
2a
2b
9
10
11
12
4-FC6H4I
1k
2f
1-bromonaphthalene 2c
4-FC6H4I
4-OHCC6H4Br
2d
4-FC6H4Br
2f
4-MeO2CC6H4Br
2e
a General conditions: 1 or 2 (1.0 equiv), ArBr (1.2 equiv), Pd(OAc)2
(2 mol%), Ph3P (4 mol%), Bu3N (2 equiv), DMF (10 mL), 125–130
°C.
a General conditions: 1–5 (1.0 equiv), ArX (X = Br; I) (1.2 equiv),
Pd(OAc)2 (2 mol%), Ph3P (4 mol%), nBu3N (2 equiv), DMF 10 mL,
125–130 °C.
b Isolated yield after flash column chromatography.
b Isolated yield after flash column chromatography.
To examine the effect of the diyne on the C–H functional-
ization, and to study the generality of the method in pre-
paring more-highly functionalized benzo[f]isoindoline
derivatives, the reactions of various 1,6-diynes (3, 4, and
5) with various aryl halides were studied (Table 2). The
results indicate that various benzo[f]isoindoline could be
constructed in a one-pot process in good yields by reac-
tion of the corresponding diynes with aryl halides
(Table 2, entries 1–8). However, the reaction of substrates
having strongly electron-donating methoxy groups (5)
with 1-bromonaphthalene gave the corresponding tetracy-
All the new benzo[f]isoindoline polycycles were fully
characterized by various spectroscopic techniques (1H
NMR, 13C NMR, UV, and IR), and by high-resolution
mass spectrometry.
On the basis of the above observations, a plausible mech-
anism is proposed for the selective formation polycyclic
heterocycles (Scheme 1). Coordination and insertion of
the arylpalladium(II) halide in the diyne substrate pro-
duces the intermediate I (‘Heck-type’ product), which
then reacts with the C=C double bond through a carbopal-
ladation reaction and s-bond metathesis onto the aryl
Synthesis 2010, No. 20, 3467–3473 © Thieme Stuttgart · New York

PAPER
4,9-Diphenyl-2,3-dihydro-1H-benzo[f]isoindoles
3469
Ethyl 4,9-Diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoindole-
6-carboxylate (1a); Typical Procedure
group via the intermediate II. This is followed by proton
abstraction12 by the base to give the benzo[f]isoindoline
polycyclic product.
4-Methyl-N,N-bis(3-phenylprop-2-yn-1-yl)benzenesulfonamide
(1; 1.0 equiv), 4-BrC6H4CO2Et (1.2 equiv), Pd(OAc)2 (2 mol%),
and Ph3P (4 mol%) were added to the degassed solution of Bu3N (2
equiv) in DMF (5 mL). The mixture was stirred at rt for 30 min,
heated at 125 °C for 20 h, and then cooled. The reaction was
quenched with H2O, and the mixture was extracted with EtOAc (20
mL). The combined organic layers were washed sequentially with
5% aq HCl (5 mL), 5% aq Na2CO3 (5 mL), and brine (3 × 5 mL),
then dried (MgSO4), and concentrated. The residue was subjected to
flash chromatography [silica gel, PE–EtOAc (6:1)] to give a white
solid; mp 250–251 °C; Rf = 0.48 (PE–EtOAc, 6:1).
Pd0
Pd
X
PG
N
PG
N
PhX
I
FT-IR (KBr): 2978, 1716, 1344, 1287, 1255, 1096, 606 cm–1.
1H NMR (300 MHz, CDCl3): d = 8.39 (s, 1 H), 7.92 (d, J = 8.5 Hz,
1 H), 7.70–7.67 (m, 3 H), 7.63–7.45 (m, 6 H), 7.31–7.29 (m, 6 H),
4.56 (s, 4 H), 4.32 (q, J = 6.9 Hz, 2 H), 2.40 (s, 3 H), 1.32 (t, J = 6.9
Hz, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 166.6, 143.7, 137.1, 136.8,
135.4, 134.4, 133.8, 131.6, 129.8, 129.3, 128.9, 128.8, 128.1, 127.8,
127.6, 126.1, 125.2, 61.1, 53.6, 53.5, 21.5, 14.2.
– [HPdX]
PG
N
PG N
Pd
H
HRMS (EI): m/z calcd for C34H29NO4S: 547.1817; found:
X
547.1887.
UV/Vis (MeCN): lmax = 252 nm.
II
1-(4,9-Diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoindol-6-
yl)ethanone (1b)
Scheme 1 Proposed mechanism for the domino reaction
White solid; mp 245–246 °C; Rf = 0.46 (PE–EtOAc, 6:1).
To summarize, we have developed an efficient method for
the synthesis of 3,3-disubstituted 4,9-diphenyl-2,3-dihy-
dro-1H-benzo[f]isoindoline derivatives in good yields and
excellent regioselectivities under mild conditions by cy-
clization of a diyne with an aryl halides in the presence of
a palladium(II) acetate based catalytic system. This meth-
od provides direct, easy, and economic construction of
FT-IR (KBr): 2859, 1686, 1599, 1344, 1240, 1157, 1096, 706, 596
cm–1.
1H NMR (300 MHz, CDCl3): d = 8.24 (s, 1 H), 7.89 (d, J = 8.5 Hz,
1 H), 7.70–7.68 (m, 4 H), 7.59–7.50 (m, 5 H), 7.32–7.26 (m, 6 H),
4.56 (s, 4 H), 2.49 (s, 3 H), 2.39 (s, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 198.0, 143.8, 137.0, 136.7,
135.7, 135.3, 134.5, 134.4, 134.0, 133.9, 131.7, 129.8, 129.4, 129.0,
fused p-conjugated polycyclic heterocycles through mul- 128.4, 128.2, 128.0, 127.6, 126.5, 123.9, 53.6, 53.5, 26.5, 21.5.
tistep C–C bond formation and C–H activation of the ben-
zene ring. In addition to the synthetic utility of the
reaction, its ability to combine direct arylation into this
class of tandem processes raises confidence in the viabil-
ity of other domino processes involving alkenylpalladi-
um(II) reactive intermediates. Further investigation to
understand this catalytic transformation, evaluation of the
HRMS (EI): m/z calcd for C33H27NO3S: 517.1712; found:
517.1779.
UV/Vis (MeCN): lmax = 265 nm.
4,9-Diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoindole-6-car-
bonitrile (1c)
White solid; mp 258–259 °C; Rf = 0.46 (PE–EtOAc, 6:1).
process with a broader scope of substrates, synthesis of FT-IR (KBr): 2860, 2226, 1599, 1491, 1344, 1157, 1096, 667 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.99 (s, 1 H), 7.79 (d, J = 7.3 Hz,
2 H), 7.71–7.68 (m, 5 H), 7.49–7.46 (m, 4 H), 7.29–7.27 (m, 5 H),
4.56 (s, 4 H), 2.41 (s, 3 H).
more-complex p-system heterocycles, and the develop-
ment of functional organic materials are in progress.
13C NMR (75.5 MHz, CDCl3): d = 143.5, 136.4, 132.8, 132.7,
132.2, 131.5, 129.8, 129.2, 129.1, 128.9, 128.7, 128.6, 128.5, 127.9,
127.6, 127.2, 126.3, 119.1, 118.3, 112.4, 109.4, 53.5, 53.4, 21.5.
All melting points were determined on a Gallenkamp melting-point
apparatus and are uncorrected. IR spectra were recorded on a Nico-
let 5DX spectrophotometer. The 1H NMR spectra were recorded in
CDCl3 using TMS as an internal reference on a Bruker Avance 300
NMR spectrometer operating at 300 MHz. The 13C NMR spectra
were determined using TMS as an internal reference with a Bruker
Avance 300 spectrometer operating at 75.5 MHz. HRMS spectra
were recorded on an Agilent 6200 LC/MS TOF spectrometer in EI
mode (70 eV). Flash column chromatography was performed on
silica gel (230–240 mesh). All the organic solvents were dried over
appropriate drying agents and distilled before use. All the chemicals
used in this study were sourced commercially.
HRMS (EI): m/z calcd for C32H24N2O2S: 500.1558; found:
500.1619.
UV/Vis (MeCN): lmax = 250 nm.
6-Chloro-4,9-diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoin-
dole (1d)
White solid; mp 235–236 °C; Rf = 0.46 (PE–EtOAc, 6:1).
FT-IR (KBr): 2858, 1599, 1494, 1344, 1157, 1096, 605 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.77 (d, J = 7.7 Hz, 2 H), 7.54–
7.29 (m, 6 H), 7.59–7.43 (m, 3 H), 7.32–7.28 (m, 6 H), 4.53 (s, 4 H),
2.40 (s, 3 H).
Synthesis 2010, No. 20, 3467–3473 © Thieme Stuttgart · New York

3470
Y.-m. Hu et al.
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13C NMR (75.5 MHz, CDCl3): d = 143.7, 137.1, 136.9, 134.2,
133.2, 132.2, 130.6, 129.8, 129.3, 129.0, 128.9, 128.8, 128.1, 127.9,
127.6, 126.7, 125.9, 125.5, 124.7, 120.7, 54.3, 53.8, 53.6, 53.1,
21.5.
1H NMR (300 MHz, CDCl3): d = 8.38 (s, 1 H), 7.92 (d, J = 8.7 Hz,
1 H), 7.70–7.64 (m, 3 H), 7.57–7.51 (m, 6 H), 7.32–7.26 (m, 6 H),
4.56 (s, 4 H), 3.87 (s, 3 H), 2.40 (s, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 167.1, 143.8, 137.1, 136.9,
135.5, 135.2, 134.5, 133.9, 131.6, 129.8, 129.4, 129.0, 128.9, 128.8,
128.3, 128.2, 127.7, 127.4, 126.2, 125.3, 53.6, 53.5, 52.2, 21.5.
HRMS (EI): m/z calcd for C31H24ClNO2S: 509.1216; found:
509.1275.
UV/Vis (MeCN): lmax = 248 nm.
HRMS (EI): m/z calcd for C33H27NO4S: 533.1661; found:
533.1733.
7,11-Diphenyl-9-tosyl-9,10-dihydro-8H-naphtho[1,2-f]isoin-
dole (1e)
UV/Vis (MeCN): lmax = 253 nm.
White solid; mp 268–269 °C; Rf = 0.46 (PE–EtOAc, 6:1).
6-Methyl-4,9-diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoin-
dole (1i)
White solid; mp 266–267 °C; Rf = 0.43 (PE–EtOAc, 6:1).
FT-IR (KBr): 3053, 2846, 1597, 1493, 1443, 1348, 1159, 1093, 705,
699 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.77 (d, J = 7.6 Hz, 1 H), 7.69–
7.66 (m, 3 H), 7.64–7.38 (m, 6 H), 7.31–7.26 (m, 2 H), 7.31–7.26
(m, 6 H), 7.09–7.04 (m, 2 H), 4.58 (s, 2 H), 4.51 (s, 2 H), 2.40 (s, 3
H).
13C NMR (75.5 MHz, CDCl3): d = 143.6, 142.1, 138.3, 135.4,
133.2, 133.1, 131.9, 129.9, 129.8, 129.5, 128.9, 128.3, 127.9, 127.8,
127.6, 127.5, 126.2, 125.3, 124.5, 54.7, 54.1, 21.5.
FT-IR (KBr): 2858, 1597, 1493, 1344, 1157, 1096, 752, 704 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.69 (d, J = 7.4 Hz, 2 H), 7.63–
7.58 (m, 5 H), 7.42–7.38 (m, 4 H), 7.22–7.18 (m, 5 H), 7.19 (d,
J = 7.6 Hz, 1 H), 4.53 (s, 4 H), 2.40 (s, 3 H), 2.36 (s, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 143.6, 137.8, 135.6, 133.5,
132.9, 132.8, 132.5, 131.9, 130.6, 129.8, 128.8, 128.7, 128.1, 127.9,
127.8, 127.6, 125.9, 125.8, 124.8, 53.6, 53.5, 21.7, 21.5.
HRMS (EI): m/z calcd for C35H27NO2S: 525.1762; found:
525.1819.
HRMS (EI): m/z calcd for C32H27NO2S: 489.1762; found:
489.1837.
UV/Vis (MeCN): lmax = 271 nm.
UV/Vis (MeCN): lmax = 239 nm.
6-Mesyl-4,9-diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoin-
dole (1f)
White solid; mp 279–280 °C; Rf = 0.46 (PE–EtOAc, 6:1).
4,9-Diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoindole (1j)
White solid; mp 270–271 °C; Rf = 0.39 (PE–EtOAc, 6:1).
FT-IR (KBr): 2857, 1597, 1494, 1344, 1159, 1093, 704, 678 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.69 (d, J = 7.5 Hz, 2 H), 7.64–
7.61 (m, 3 H), 7.55–7.52 (m, 6 H), 7.33–7.28 (m, 7 H), 4.56 (s, 4 H),
2.40 (s, 3 H).
FT-IR (KBr): 3055, 2926, 1599, 1495, 1342, 1038, 1157, 756, 705
cm–1.
1H NMR (300 MHz, CDCl3): d = 8.29 (s, 1 H), 7.80–7.78 (m, 2 H),
7.70–7.67 (m, 2 H), 7.57–7.53 (m, 4 H), 7.36–7.30 (m, 8 H), 4.57
(s, 4 H), 3.01 (s, 3 H), 2.41 (s, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 143.9, 137.6, 136.7, 136.5,
135.2, 134.4, 131.5, 129.9, 129.3, 129.1, 128.9, 128.7, 127.8, 127.6,
126.8, 126.3, 122.2, 53.4, 53.5, 44.6, 44.3, 21.5.
13C NMR (75.5 MHz, CDCl3): d = 143.7, 137.7, 133.7, 133.5,
132.8, 132.3, 129.8, 129.5, 128.8, 127.9, 127.6, 125.9, 53.6, 21.5.
HRMS (EI): m/z calcd for C31H25NO2S: 475.1606; found:
475.1672.
UV/Vis (MeCN): lmax = 243 nm.
HRMS (EI): m/z calcd for C32H27NO4S2: 553.1381; found:
553.1466.
6-Fluoro-4,9-diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoin-
dole (1k)
UV/Vis (MeCN): lmax = 249 nm.
White solid; mp 263–264 °C; Rf = 0.39 (PE–EtOAc, 6:1).
FT-IR (KBr): 2858, 1597, 1492, 1444, 1342, 1157, 705, 611 cm–1.
4,9-Diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoindole-6-carb-
aldehyde (1g)
1H NMR (300 MHz, CDCl3): d = 7.69 (d, J = 7.5 Hz, 1 H), 7.64–
7.52 (m, 2 H), 7.64–7.52 (m, 6 H), 7.34–7.29 (m, 7 H), 7.21–7.12
(m, 1 H), 4.54 (s, 4 H), 2.40 (s, 3 H).
White solid; mp 252–253 °C; Rf = 0.42 (PE–EtOAc, 6:1).
FT-IR (KBr): 3055, 2858, 1697, 1597, 1493, 1344, 1157, 1096, 704,
605 cm–1.
13C NMR (75.5 MHz, CDCl3): d = 162.4, 143.7, 137.4, 137.2,
134.1, 133.4, 129.8, 129.5, 129.4, 129.3, 128.9, 128.6, 128.4, 128.2,
128.1, 127.9, 127.6, 125.8, 120.7, 116.1, 115.8, 109.6, 109.3, 53.6,
53.5, 53.1, 21.5.
1H NMR (300 MHz, CDCl3): d = 9.96 (s, 1 H), 8.11 (s, 1 H), 7.86–
7.79 (m, 4 H), 7.70–7.58 (m, 6 H), 7.34–7.30 (m, 6 H), 4.57 (s, 4 H),
2.41 (s, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 192.2, 143.8, 136.9, 136.6,
136.5, 135.3, 134.4, 133.9, 132.6, 129.8, 129.4, 129.3, 129.1, 129.0,
128.9, 128.5, 128.3, 127.6, 127.1, 122.6, 53.7, 53.6, 53.5, 21.5.
HRMS (EI): m/z calcd for C31H24FNO2S: 493.1512; found:
493.1584.
UV/Vis (MeCN): lmax = 244 nm.
HRMS (EI): m/z calcd for C32H25NO3S: 503.1555; found:
503.1610.
Ethyl 4,9-Diphenyl-2-(phenylsulfonyl)-2,3-dihydro-1H-ben-
zo[f]isoindole-6-carboxylate (2a)
UV/Vis (MeCN): lmax = 268 nm.
White solid; mp 227–228 °C; Rf = 0.42 (PE–EtOAc, 6:1).
Methyl 4,9-Diphenyl-2-tosyl-2,3-dihydro-1H-benzo[f]isoindole-
6-carboxylate (1h)
White solid; mp 247–248 °C; Rf = 0.39 (PE–EtOAc, 6:1).
FT-IR (KBr): 3059, 2974, 1717, 1444, 1340, 1285, 1245, 1157,
1096, 752, 615 cm–1.
1H NMR (300 MHz, CDCl3): d = 8.40 (s, 1 H), 7.92 (d, J = 8.4 Hz,
1 H), 7.80 (d, J = 6.2 Hz, 2 H), 7.68–7.64 (m, 1 H), 7.59–7.50 (m, 8
H), 7.34–7.28 (m, 5 H), 4.59 (s, 4 H), 4.32 (q, J = 6.3 Hz, 2 H), 1.33
(t, J = 6.2 Hz, 3 H).
FT-IR (KBr): 2949, 1720, 1599, 1440, 1344, 1285, 1252, 1159,
1096, 704, 605 cm–1.
Synthesis 2010, No. 20, 3467–3473 © Thieme Stuttgart · New York

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4,9-Diphenyl-2,3-dihydro-1H-benzo[f]isoindoles
3471
13C NMR (75.5 MHz, CDCl3): d = 166.6, 137.1, 136.8, 135.3,
134.4, 133.8, 132.9, 131.6, 129.4, 129.3, 129.2, 128.9, 128.8, 128.3,
128.2, 127.8, 127.5, 126.3, 125.3, 61.1, 53.7, 53.6, 14.2.
13C NMR (75.5 MHz, CDCl3): d = 167.1, 137.1, 136.8, 135.4,
133.8, 132.9, 131.6, 129.4, 129.3, 129.0, 128.9, 128.8, 128.3, 128.2,
127.5, 126.3, 125.3, 53.7, 53.6, 52.2.
HRMS (EI): m/z calcd for C33H27NO4S: 533.1661; found:
HRMS (EI): m/z calcd for C32H25NO4S: 519.1504; found:
533.1734.
519.1574.
UV/Vis (MeCN): lmax = 251 nm.
UV/Vis (MeCN): lmax = 253 nm.
1-[4,9-Diphenyl-2-(phenylsulfonyl)-2,3-dihydro-1H-ben-
zo[f]isoindol-6-yl]ethanone (2b)
White solid; mp 203–204 °C; Rf = 0.40 (PE–EtOAc, 6:1).
6-Fluoro-4,9-diphenyl-2-(phenylsulfonyl)-2,3-dihydro-1H-ben-
zo[f]isoindole (2f)
White solid; mp 245–246 °C; Rf = 0.39 (PE–EtOAc, 6:1).
FT-IR (KBr): 3057, 2860, 1684, 1599, 1444, 1346, 1155, 1097, 723,
621 cm–1.
FT-IR (KBr): 3059, 2860, 1627, 1445, 1344, 1161, 1097, 721, 621
cm–1.
1H NMR (300 MHz, CDCl3): d = 8.25 (s, 1 H), 7.89 (d, J = 8.6 Hz,
1 H), 7.80 (d, J = 6.8 Hz, 1 H), 7.68 (d, J = 7.6 Hz, 2 H), 7.69–7.66
(m, 1 H), 7.57–7.51 (m, 8 H), 7.35–7.29 (m, 4 H), 4.59 (s, 4 H), 2.50
(s, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 197.9, 136.9, 136.8, 135.6,
134.4, 133.9, 132.9, 129.4, 129.3, 129.2, 129.0, 128.9, 128.4, 128.2,
127.9, 127.5, 126.5, 123.9, 53.6, 53.5, 26.5.
1H NMR (300 MHz, CDCl3): d = 7.80 (d, J = 6.7 Hz, 2 H), 7.64–
7.60 (m, 4 H), 7.54–7.52 (m, 6 H), 7.32–7.29 (m, 5 H), 7.12 (t,
J = 8.3 Hz, 1 H), 4.57 (s, 4 H).
13C NMR (75.5 MHz, CDCl3): d = 162.5, 137.4, 137.1, 134.1,
132.9, 129.5, 129.3, 129.2, 129.1, 129.0, 128.9, 128.8, 128.6, 128.4,
128.2, 128.1, 127.9, 127.5, 125.9, 116.2, 115.6, 109.6, 109.3, 53.6,
53.5.
HRMS (EI): m/z calcd for C32H25NO3S: 503.1555; found:
HRMS (EI): m/z calcd for C30H22FNO2S: 479.1365; found:
503.1626.
479.1427.
UV/Vis (MeCN): lmax = 265 nm.
UV/Vis (MeCN): lmax = 240 nm.
7,11-Diphenyl-9-(phenylsulfonyl)-9,10-dihydro-8H-naph-
tho[1,2-f]isoindole (2c)
White solid; mp 239–240 °C; Rf = 0.41 (PE–EtOAc, 6:1).
Ethyl 4,9-Bis(4-tolyl)-2-tosyl-2,3-dihydro-1H-benzo[f]isoin-
dole-6-carboxylate (3a)
White solid; mp 252–253 °C; Rf = 0.39 (PE–EtOAc, 6:1).
FT-IR (KBr): 3057, 2851, 1597, 1445, 1348, 1312, 1163, 1097, 721,
619 cm–1.
FT-IR (KBr): 2978, 2920, 1717, 1516, 1344, 1285, 1250, 1157,
1096, 675, 607 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.79–7.72 (m, 5 H), 7.79–7.08 (m,
9 H), 7.57–7.50 (m, 5 H), 7.09–7.02 (m, 2 H), 4.57 (d, J = 19.2 Hz,
4 H).
13C NMR (75.5 MHz, CDCl3): d = 142.1, 138.3, 136.8, 135.3,
133.2, 132.8, 131.9, 130.5, 129.9, 129.5, 129.2, 128.9, 128.4, 128.0
127.9, 127.6, 127.4, 126.2, 125.3, 124.5, 54.7, 54.1.
1H NMR (300 MHz, CDCl3): d = 8.42 (s, 1 H), 7.89 (d, J = 7.8 Hz,
1 H), 7.68 (d, J = 7.1 Hz, 3 H), 7.36–7.34 (m, 4 H), 7.31–7.29 (m, 2
H), 7.21–7.19 (m, 4 H), 4.56 (s, 4 H), 4.33(q, J = 6.9 Hz, 2 H), 2.50
(s, 6 H), 2.40 (s, 3 H), 1.33 (t, J = 6.75 Hz, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 166.7, 143.7, 137.9, 137.8,
135.5, 134.6, 134.2, 133.9, 133.6, 133.5, 131.7, 129.8, 129.6, 129.3,
129.2, 128.9, 127.6, 126.2, 125.0, 61.0, 53.7, 53.6, 21.5, 21.3, 14.3.
HRMS (EI): m/z calcd for C34H25NO2S: 511.1606; found:
511.1680.
HRMS (EI): m/z calcd for C36H33NO4S: 575.2130; found:
575.2201.
UV/Vis (MeCN): lmax = 270 nm.
UV/Vis (MeCN): lmax = 251 nm.
4,9-Diphenyl-2-(phenylsulfonyl)-2,3-dihydro-1H-benzo[f]isoin-
dole-6-carbaldehyde (2d)
White solid; mp 215–216 °C; Rf = 0.39 (PE–EtOAc, 6:1).
7,11-Bis(4-methylphenyl)-9-tosyl-9,10-dihydro-8H-naph-
tho[1,2-f]isoindole (3b)
White solid; mp 266–267 °C; Rf = 0.49 (PE–EtOAc, 6:1).
FT-IR (KBr): 3057, 2965, 1682, 1622, 1445, 1346, 1163, 1097, 721,
613 cm–1.
1H NMR (300 MHz, CDCl3): d = 9.49 (s, 1 H), 7.83–7.80 (m, 4 H),
7.61–7.54 (m, 8 H), 7.36–7.30 (m, 6 H), 4.59 (s, 4 H).
13C NMR (75.5 MHz, CDCl3): d = 195.3, 149.1, 144.7, 137.1,
132.9, 132.3, 129.4, 129.3, 129.2, 129.1, 129.0, 128.9, 128.3, 128.2,
127.9, 127.5, 127.2, 126.8, 126.5, 122.7, 53.7, 53.6.
FT-IR (KBr): 3026, 2864, 1512, 1443, 1331, 1153, 1097, 752, 669
cm–1.
1H NMR (300 MHz, CDCl3): d = 7.75–7.67 (m, 5 H), 7.57–7.54 (m,
2 H), 7.37–7.29 (m, 6 H), 7.21–7.10 (m, 5 H), 4.57 (s, 2 H), 4.51 (s,
2 H), 2.53 (s, 3 H), 2.51 (s, 3 H), 2.40 (s, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 139.1, 137.6, 137.4, 135.5,
133.3, 133.0, 130.6, 129.8, 129.5, 128.3, 128.1, 127.5, 127.4, 126.1,
125.2, 124.6, 54.8, 54.2, 21.5, 21.4, 21.3.
HRMS (EI): m/z calcd for C31H23NO3S: 489.1379; found:
489.1468.
HRMS (EI): m/z calcd for C37H31NO2S: 553.2075; found:
553.2134.
UV/Vis (MeCN): lmax = 293 nm.
Methyl 4,9-Diphenyl-2-(phenylsulfonyl)-2,3-dihydro-1H-ben-
zo[f]isoindole-6-carboxylate (2e)
White solid; mp 215–216 °C; Rf = 0.38 (PE–EtOAc, 6:1).
UV/Vis (MeCN): lmax = 268 nm.
Methyl 4,9-Bis(4-methylphenyl)-2-tolyl-2,3-dihydro-1H-ben-
zo[f]isoindole-6-carboxylate (3c)
White solid; mp 260–261 °C; Rf = 0.45 (PE–EtOAc, 6:1).
FT-IR (KBr): 2949, 1720, 1444, 1346, 1287, 1252, 1155, 1097, 752,
619 cm–1.
FT-IR (KBr): 3024, 2863, 1718, 1516, 1443, 1345, 1285, 1252,
1157, 1096, 813, 675 cm–1.
1H NMR (300 MHz, CDCl3): d = 8.37 (s, 1 H), 7.92 (d, J = 8.5 Hz,
1 H), 7.80 (d, J = 7.0 Hz, 2 H), 7.70–7.67 (m, 4 H), 7.58–7.47 (m, 5
H), 7.31–7.27 (m, 5 H), 4.58 (s, 4 H), 3.86 (s, 3 H).
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Methyl 4,9-Bis(4-chlorophenyl)-2-tosyl-2,3-dihydro-1H-ben-
zo[f]isoindole-6-carboxylate (4d)
White solid; mp 275–276 °C; Rf = 0.45 (PE–EtOAc, 6:1).
1H NMR (300 MHz, CDCl3): d = 8.42 (s, 1 H), 7.90 (m, 1 H), 7.70
(m, 3 H), 7.36–7.22 (m, 6 H), 7.24–7.20 (m, 4 H), 4.56 (s, 4 H), 3.87
(s, 3 H), 2.52 (s, 6 H), 2.40 (s, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 167.2, 143.8, 137.9, 137.8,
135.5, 134.6, 134.1, 133.9, 133.8, 133.6, 131.7, 129.8, 129.7, 129.6,
129.3, 128.9, 127.6, 127.3, 126.3, 125.1, 53.7, 53.6, 52.3, 21.5,
21.4, 21.3.
FT-IR (KBr): 2953, 1718, 1493, 1344, 1259, 1157, 1093, 821, 675
cm–1.
1H NMR (300 MHz, CDCl3): d = 8.32 (s, 1 H), 7.96 (s, 1 H), 7.53
(d, J = 7.5 Hz, 2 H), 7.64–7.53 (m, 4 H), 7.32–7.25 (m, 7 H), 4.52
(s, 4 H), 3.89 (s, 3 H), 2.41 (s, 3 H).
HRMS (EI): m/z calcd for C35H31NO4S: 561.1974; found:
561.2043.
13C NMR (75.5 MHz, CDCl3): d = 166.80, 143.9, 135.6, 135.2,
135.0, 134.4, 134.3, 133.2, 131.4, 130.7, 129.8, 129.3, 129.2, 128.4,
127.7, 127.5, 126.0, 125.6, 53.4, 53.3, 52.3, 21.5.
UV/Vis (MeCN): lmax = 249 nm.
Ethyl 4,9-Bis(4-chlorophenyl)-2-tosyl-2,3-dihydro-1H-ben-
zo[f]isoindole-6-carboxylate (4a)
White solid; mp 262–263 °C; Rf = 0.45 (PE–EtOAc, 6:1).
HRMS (EI): m/z calcd for C33H25Cl2NO4S: 601.0881; found:
601.0934.
UV/Vis (MeCN): lmax = 251 nm.
FT-IR (KBr): 2978, 1717, 1493, 1344, 1286, 1248, 1157, 1094, 825,
605 cm–1.
1H NMR (300 MHz, CDCl3): d = 8.34 (s, 1 H), 7.95 (d, J = 7.9 Hz,
1 H), 7.70 (d, J = 7.5 Hz, 2 H), 7.63–7.27 (m, 5 H), 7.32–7.26 (m, 6
H), 4.52 (s, 4 H), 4.34 (q, J = 6.9 Hz, 2 H), 2.41 (s, 3 H), 1.35 (t,
J = 6.9 Hz, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 166.4, 143.9, 135.5, 135.4,
135.1, 134.5, 134.4, 134.3, 134.0, 131.5, 130.7, 130.6, 129.9, 129.3,
128.5, 128.2, 127.6, 125.9, 125.6, 124.7, 61.2, 53.4, 53.3, 21.5,
18.2.
7,11-Bis(4-methoxyphenyl)-9-tosyl-9,10-dihydro-8H-naph-
tho[1,2-f]isoindole (5a)
White solid; mp 245–246 °C; Rf = 0.45 (PE–EtOAc, 6:1).
FT-IR (KBr): 2833, 1608, 1514, 1460, 1335, 1244, 1163, 1097,
1029, 831, 667 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.78–7.68 (m, 4 H), 7.60–7.56 (m,
2 H), 7.43–7.38 (m, 2 H), 7.25–7.19 (m, 5 H), 7.14–7.08 (m, 5 H),
4.59 (s, 2 H), 4.52 (s, 2 H), 3.95 (s, 6 H), 2.40 (s, 3 H).
13C NMR (75.5 MHz, CDCl3): d = 159.2, 159.1, 143.6, 135.8,
134.3, 134.2, 133.9, 133.5, 133.1, 132.3, 130.7, 130.4, 129.8, 129.4,
128.4, 127.9, 127.6, 127.4, 126.1, 125.3, 124.5, 115.3, 114.3, 55.4,
55.3, 54.7, 54.2, 21.5.
HRMS (EI): m/z calcd for C34H27Cl2NO4S: 615.1038; found:
615.1103.
UV/Vis (MeCN): lmax = 250 nm.
HRMS (EI): m/z calcd for C37H31NO4S: 585.1974; found:
585.2043.
7,11-Bis(4-chlorophenyl)-9-tosyl-9,10-dihydro-8H-naph-
tho[1,2-f]isoindole (4b)
White solid; mp 255–256 °C; Rf = 0.46 (PE–EtOAc, 6:1).
UV/Vis (MeCN): lmax = 236 nm.
FT-IR (KBr): 3049, 1597, 1491, 1350, 1094, 817, 671 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.80 (d, J = 7.7 Hz, 1 H), 7.69 (d,
J = 7.9 Hz, 1 H), 7.64–7.60 (m, 5 H), 7.56–7.48 (m, 3 H), 7.32–7.26
(m, 6 H), 7.17–7.12 (m, 2 H), 4.54 (s, 2 H), 4.48 (s, 2 H), 2.41 (s, 3
H).
Acknowledgment
The authors thank the National Science Foundation of China
(20872002) for financial support.
13C NMR (75.5 MHz, CDCl3): d = 140.4, 136.5, 135.4, 134.2,
133.9, 133.4, 133.1, 130.8, 130.2, 129.9, 129.8, 129.2, 128.6, 128.0,
127.8, 127.6, 126.4, 125.6, 124.0, 54.5, 53.9, 21.5.
References
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Blackwell Science: Oxford, 2000. (b) Eicher, T.;
HRMS (EI): m/z calcd for C35H25Cl2NO2S: 593.0983; found:
593.1049.
Hauptmann, S. The Chemistry of Heterocycles; Wiley-
VCH: New York, 2003. (c) Brunetti, F. G.; Gong, X.; Tong,
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UV/Vis (MeCN): lmax = 274 nm.
6-Chloro-4,9-bis(4-chlorophenyl)-2-tosyl-2,3-dihydro-1H-ben-
zo[f]isoindole (4c)
White solid; mp 276–277 °C; Rf = 0.45 (PE–EtOAc, 6:1).
FT-IR (KBr): 3030, 2860, 1597, 1493, 1344, 1157, 1094, 1014, 821,
669 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.69 (d, J = 6.5 Hz, 2 H), 7.56–
7.52 (m, 6 H), 7.33–7.30 (m, 3 H), 7.29–7.25 (m, 4 H), 4.50 (s, 4 H),
2.41 (s, 3 H).
(3) For multiple domino reactions, see: (a) Tietze, L. F.;
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13C NMR (75.5 MHz, CDCl3): d = 143.9, 135.4, 135.2, 134.5,
134.4, 134.3, 133.4, 132.6, 130.8, 130.7, 129.9, 129.4, 129.3, 129.2,
127.6, 127.4, 127.1, 124.5, 53.4, 53.3, 21.5.
HRMS (EI): m/z calcd for C31H22Cl3NO2S: 577.0437; found:
577.0497.
UV/Vis (MeCN): lmax = 245 nm.
Synthesis 2010, No. 20, 3467–3473 © Thieme Stuttgart · New York

PAPER
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Synthesis 2010, No. 20, 3467–3473 © Thieme Stuttgart · New York