Organocatalytic diels-alder reaction of 2-vinylindoles with methyleneindolinones: An efficient approach to functionalized carbazolespirooxindoles

Article abstract of DOI:10.1002/adsc.201400780

An unprecedented asymmetric Diels-Alder reaction of 2-vinylindoles with methyleneindolinones has been disclosed. Under bifunctional organocatalysis by cinchona-derived squaramide catalyst, a series of diversely functionalized carbazolespirooxindole derivatives bearing three contiguous stereocenters are rapidly constructed under mild conditions (48-90% yields, up to >20:1 dr and 99% ee).

Full text of DOI:10.1002/adsc.201400780

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DOI: 10.1002/adsc.201400780
Organocatalytic Diels–Alder Reaction of 2-Vinylindoles with
Methyleneindolinones: An Efficient Approach to Functionalized
Carbazolespirooxindoles
Lin-Jie Huang,a Jiang Weng,a,* Sheng Wang,a and Gui Lua,b,*
a
Institute of Medicinal Chemistry, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, Peopleꢀs
Republic of China
Fax : (+86)-20-3994-3048; e-mail: lugui@mail.sysu.edu.cn or wengj2@mail.sysu.edu.cn
Institute of Human Virology, Sun Yat-sen University, Guangzhou 510080, Peopleꢀs Republic of China
b
Received: August 6, 2014; Revised: November 26, 2014; Published online: && &&, 0000
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201400780.
Abstract: An unprecedented asymmetric Diels– centers are rapidly constructed under mild conditions
Alder reaction of 2-vinylindoles with methyleneindo- (48–90% yields, up to >20:1 dr and 99% ee).
linones has been disclosed. Under bifunctional orga-
nocatalysis by cinchona-derived squaramide catalyst,
a series of diversely functionalized carbazolespiroox- Keywords: asymmetric catalysis; cycloaddition; in-
indole derivatives bearing three contiguous stereo- doles; organocatalysis; spiro compounds
Introduction
the D–A reaction, vinylindoles[6,7] have recently been
broadly applied in this transformation for the synthe-
The proficiency with which nature constructs structur- sis of biologically significant tetrahydrocarbazole de-
al complexity has inspired generations of synthetic rivatives. In 2008, Ricci et al.[7e] developed an organo-
chemists to develop efficient synthetic strategies and catalytic asymmetric Diels–Alder reaction of 3-vinyl-
methodologies for rapidly accessing intricate molecu- indoles with maleimides and quinines to afford opti-
lar architectures.[1] Despite the significant progress cally active tetrahydrocarbazoles. Recently, the Mac-
that has been made so far, efficient and practical Millanꢀs group described the total syntheses of
asymmetric approaches remain in high demand. In alkaloids including (+)-minfiensine,[8a] (À)-vincori-
particular, a challenge comes with the construction of ne[8b] and (À)-minovincine,[8c] which are based on
highly functional polycyclic molecules containing tandem Diels–Alder cyclization of 2-vinylindole de-
spiro-stereocenters and multiple contiguous stereo- rivatives. On the other hand, methyleneindolinone
centers.[2]
has been recently proved to be a versatile synthon for
The spirooxinole[3] and tetrahydrocarbazole[4] skele- accessing the spirooxindole motifs through acting as
tons containing multiple stereogenic centers are fea- Michael acceptor and dipolarophile in cascade reac-
tured in a range of natural alkaloids and bioactive tions and cycloaddition reactions.[9]
compounds (Figure 1), which exhibit a wide spectrum
Therefore, we envisioned that the desired carbazo-
of interesting bioactivities, such as anticancer, antide- lespirooxindole skeleton could be constructed by
pressant and antimalaria properties. Considering the a [4+2] D–A reaction of vinylindole with methyle-
versatile and relevant bioactivities of these two privi- neindolinone. The challenges associated with the ste-
leged spirooxindole and tetrahydrocarbazole struc- reocontrolled construction of the carbazolespirooxin-
tures, we hypothesized that the combination of the dole core arise from the great steric hindrance while
two structural units into one molecule might result in introducing the quaternary spirostereocenter. Recent-
the discovery of novel scaffolds with significant bioac- ly, Barbasꢀs and Fengꢀs groups have reported the
tivities.
asymmetric synthesis of the carbazolespirooxindole
The catalytic asymmetric Diels–Alder (D–A) cyclo- skeleton via asymmetric D–A reaction between 3-vi-
addition reaction has served as a powerful tool for nylindoles and methyleneindolinones by using an or-
the rapid construction of complex cyclic molecules.[5] ganocatalyst and a metal complex catalyst (Scheme 1,
Among the different diene counterparts being used in a), respectively.[7c,f] Inspired by the previous work,
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Figure 1. Representative biologically active compounds containing spirooxindole or tetrahydrocarbazole scaffolds.
Scheme 1. Synthesis of carbazolespirooxindole scaffolds via D–A reactions.
herein we describe an efficient and unprecedented or- through H-bonding interaction. As shown in Table 1,
ganocatalytic asymmetric D–A reaction of 2-vinylin- in the presence of the cinchonine-derived thiourea
doles with methyleneindolinones for the synthesis of catalyst (Table 1, entry 1), the desired product 3a was
a new series of potentially biologically important car- obtained in low yield and low enantioselectivity. To
bazolespirooxindole derivatives (Scheme 1, b).
our delight, when changing the catalyst framework to
cinchonidine-thiourea catalyst II (entry 2), the ee
value was improved to 55%. Next, the cinchonidine-
based squaramides IIIa and IIIb were examined, and
IIIa showed much higher stereoselectivity than the
Results and Discussion
Initially, the D–A reaction between (E)-1-methyl-2- corresponding thiourea catalyst II (entry 3 vs.
styryl-1H-indole 1a and N-Boc-protected methylene- entry 2). Squaramide catalysts containing chiral sub-
ACHTUNGTRENNUNGindolinone 2a was selected as the model reaction. In- stituents on the other end of the squaramide (IIIc and
spired by the pioneering work on hydrogen bond-cat- IIId) were also evaluated, resulting in lower yields
alyzed D–A reactions,[10] we envisioned that Cinchona and enantioselectivities (Table 1, entries 5 and 6). To
alkaloid-derived thiourea[11] and squaramide[12] orga- our surprise, bisthiourea catalysts IVa and IVb, which
nocatalysts could interact with methyleneindolinones efficiently catalyze the D–A reaction of 3-vinylindoles
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Organocatalytic Diels–Alder Reaction of 2-Vinylindoles with Methyleneindolinones
Table 1. Optimization of the reaction conditions.[a]
Entry
Catalyst
Solvent
Yield [%][b]
dr[c]
ee [%][d]
1
2
3
4
5
6
7
8
I
II
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
THF
toluene
n-hexane
CHCl3
CH2Cl2
CH2Cl2
CH2Cl2
25
30
36
33
27
41
67
53
48
66
39
63
63
44
66
4:1
À27
55
88
À5
4
À5
À36
17
70
17
0
>20:1
10:1
>20:1
14:1
>20:1
10:1
6:1
10:1
3:1
8:1
IIIa
IIIb
IIIc
IIId
IVa
IVb
IIIa
IIIa
IIIa
IIIa
IIIa
IIIa
IIIa
9
10
11
12
13[e]
14[f]
15[g]
10:1
7:1
10:1
10:1
65
90
96
84
[a]
Unless otherwise specified, all reactions were carried out with catalyst (10 mol%), 1a (0.15 mmol) and 2a (0.10 mmol) in
the indicated solvent (1.0 mL) at room temperature.
[b]
[c]
[d]
[e]
[f]
Isolated yields of 3a.
1
Determined by H NMR analysis of the crude products.
Determined by chiral-phase HPLC analysis.
Portionwise addition of 2a every 5 min for three times.
0.10 mmol 1a was used; portionwise addition of 2a every 5 min for three times.
The solution of 2a (0.10 mmol) in CH2Cl2 (0.5 mL) was added to 1a (0.15 mmol) in CH2Cl2 (0.5 mL) by syringe pump in
20 min.
[g]
and methyleneindolinones,[7c] provided the products in tially,[13] we optimized the ratio and feeding mode of
moderate yields and poor stereoselectivities (entries 7 substrate 2a (entries 13–15). It was found that the
and 8). Furthermore, the screening of a variety of sol- yield of product was increased and the ee value was
vents such as THF, toluene, n-hexane and chloroform, maintained when 2a was added in three separate por-
could not result in any improvement in terms of yield, tions every five minutes (entry 14). Under optimal
diastereoselectivity and enantioselectivity (entries 9– conditions, the desired product 3a can be isolated
12). With observation of the competitive side reaction with 63% yield, 7:1 dr and 90% ee in 20 min
of cycloadduct 3a with substrate 2a (Scheme 3), which (entry 13).
might reduce the yield of the D–A reaction substan-
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Scheme 2. Gram-scale preparation of 3a.
Scheme 3. Tandem D–A/Michael/aromatization reaction.
With the optimized reaction conditions in hand, we position of the substituent also had an effect on the
next examined the scope and limitation of the D–A stereoselectivity, 2-vinylindoles bearing the electron-
reactions using various 2-vinylindoles and methyle- donating methoxy group at the para (1c) or ortho (1e)
neindolinones. The results are summarized in Table 2. position of the phenyl ring were far superior to the
All reactions were performed in CH2Cl2 at room tem- meta-substituted counterpart (1d) in stereoselective
perature for 20 min in the presence of 10 mol% cin- control (Table 2, entris 3–5). In addition, 5-methoxy-
chonidine-squaramide catalyst IIIa. For b-aryl-substi- substituted 2-vinylindole (1k) could also participate in
tuted 2-vinylindoles, the substrates with neutral, elec- this reaction efficiently to afford the desired product
tron-withdrawing or electron-donating groups at the in high yield and excellent stereoselectivity (entry 11).
para-, meta- or ortho-position of the b-aryl ring were Furthermore, when more sterically hindered N-
investigated (Table 2, entries 1–12). In most cases, the benzyl-protected substrate 1l was employed, the reac-
cycloadducts were obtained in moderate to good tion also proceeded smoothly, affording the product
yields (52–84%) with high diastereoselectivities (up to 3k in high yield and enantioselectivity (entry 12, 65%
>20:1 dr) and excellent enantioselectivities (up to yield, 88% ee).
99% ee). It also appeared that the electronic proper-
Further exploration of the substrate scope was fo-
ties of the b-aryl group of 2-vinylindoles showed an cused upon various substituted methyleneindolinones
obvious influence on the results (entries 1–10). Gener- (Table 3). As shown in entries 1–6, the methylenein-
ally, 2-vinylindoles 1 with electronically rich substitu- dolinones (2b–2e) with electron-withdrawing (en-
ents on the b-aryl moiety exhibited better reactivities tries 1–3 and 5) or electron-donating substituents (en-
and enantioselectivities than those with electronically tries 4 and 6) on the indolinone backbone underwent
poor substituents (entries 2–5 vs. 6–10). Besides, the the reaction efficiently, giving moderate to good
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Table 2. Enantioselective Diels–Alder reactions of various 2-vinylindoles 1 with methyleneindolinone 2a.[a]
Entry
1
R1
R2
R3
Product
Yield [%][b]
dr[c]
ee [%][d]
1
2
3
4
5
6
7
8
1a
1b
1c
1d
1e
1f
1g
1h
1i
H
H
H
H
H
H
H
H
H
H
5-OMe
H
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Bn
H
3a
3b
3c
3d
3e
3f
3g
3h
3i
63
62
71
65
83
57
62
84
52
61
74
65
7:1
5:1
90
91
90
76
93
97
80
60
65
75
99
88
4-Me
4-OMe
3-OMe
2-OMe
4-Br
4-Cl
4-F
4-CN
4-Ac
H
15:1
15:1
>20:1
7:1
14:1
10:1
6:1
9:1
4:1
7:1
9
10
11
12
1j
1k
1l
3j
3k
3l
H
[a]
To a solution of 1 (0.15 mmol) and IIIa (0.01 mmol) in CH2Cl2 (1.0 mL) at room temperature was portionwise added 2
(0.10 mmol) every 5 min for three times, and the mixture was stirred for 20 min.
Isolated yields.
Determined by H NMR analysis of the crude products.
Determined by chiral-phase HPLC analysis.
[b]
[c]
[d]
1
Table 3. Enantioselective Diels–Alder reactions of 2-vinylindoles 1a and 1i with various methyleneindolinones 2.[a]
Entry
1
R1
2
R4
R5
Product
Yield [%][b]
dr[c]
ee [%][d]
1
2
3
4
5
6
7
8
9
10
1a
1a
1a
1a
1i
H
H
H
H
5-OMe
5-OMe
H
H
H
H
2b
2c
2d
2e
2b
2e
2f
2g
2h
2i
5-F
5-Cl
5-Br
5-Me
5-F
5-Me
H
H
H
H
CO2Et
CO2Et
CO2Et
CO2Et
CO2Et
CO2Et
CO2Me
COPh
CN
3m
3n
3o
3p
3q
3r
3s
3t
3u
3v
63
50
48
75
74
90
82
60
>20:1
20:1
20:1
>20:1
9:1
10:1
10:1
6:1
96
88
84
88
93
90
99
89
4
1i
1a
1a
1a
1a
63
trace
4:1
–
Ph
–
[a]
To a solution of 1 (0.15 mmol) and IIIa (0.01 mmol) in CH2Cl2 (1.0 mL) at room temperature was portionwise added 2
(0.10 mmol) every 5 min for three times, and the mixture was stirred for 20 min.
Isolated yields.
Determined by H NMR analysis of the crude products.
Determined by chiral-phase HPLC analysis.
[b]
[c]
[d]
1
yields (48–90%) and high stereoselectivities (84–96% tioselectivity (99% ee, entry 7). On the other hand,
ee, >9:1 dr). The methyl ester-substituted methylene- the benzoyl-substituted methyleneindolinone 2g was
ACHTUNGTRENNUNGindoline 2f afforded the product with excellent enan- also tolerated in the catalytic system to afford the cy-
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Figure 2. X-ray crystal structure of compound 3f.
cloadduct in 60% yield with 89% ee (entry 8), while ous stereocenters including a spiro-quaternary carbon.
the cyano-substituted methyleneindolinone 2h gave Many highly functionalized carbazolespirooxindoles
the corresponding product in nearly racemic form can be readily obtained with moderate to good yields
with 63% yield (entry 9). Unfortunately, no desired (up to 90%) and high enantioselectivities (up to 99%
product was obtained when the phenyl-substituted ee). The broad substrate scope, short reaction time
methyleneindolinone 2i served as substrate (entry 10), and mild reaction conditions make this protocol very
due to its relatively lower reactivity.
useful and attractive. Further investigations aimed at
To determine the absolute configuration of the exploring the bioactive properties of the products are
products, a single crystal of compound 3f was ob- currently underway in our laboratory.
tained
for
X-ray
crystallographic
analysis
(Figure 2).[14] The newly formed chiral centers of 3f
were confirmed as (2S,3R,4R). The configurations of Experimental Section
the other products were assigned by analogy to 3f.
Moreover, an additional scaled-up experiment General Remarks
(Scheme 2) showed that this reaction could be per-
All the commercial reagents were used as such without fur-
formed on the gram scale without obvious loss of dia-
stereoselectivity and enantioselectivity (3.0 mmol sub-
strate, 73% total yield, 4:1 dr and 86% ee).
It is worth noting that a tandem D–A/Michael/aro-
matization reaction occurred along with the desired
D–A/aromatization reaction when excess methylene-
ther purification. All solvents were used as commercial an-
hydrous grade without further purification. The flash
column chromatography was carried out over silica gel
1
(230–400 mesh). H and 13C NMR spectra were recorded on
a Bruker Avance 400 MHz spectrometer. Chemical shifts in
1H NMR spectra are reported in parts per million (ppm, d)
downfield from the internal standard Me4Si (TMS, d=
0 ppm). Chemical shifts in 13C NMR spectra are reported
relative to the central line of the chloroform signal (d=
77.0 ppm). Peaks were labeled as singlet (s), doublet (d),
triplet (t), quartet (q), and multiplet (m). High resolution
mass spectra were obtained with a Shimadzu LCMS-IT-TOF
mass spectrometer. Enantiomeric excesses of compounds
were determined by HPLC using a Daicel Chiralpak AD-H
column.
ACHTUNGTRENNUNGindolinone was subjected to the optimized conditions.
As demonstrated in Scheme 3, highly functionalized
carbazolespirooxindole 4a with six contiguous stereo-
centers was isolated in 47% yield along with 3a (42%
yield) when 2.0 equiv. of 2a was added once to the re-
action system. The configuration of 4a was tentatively
unassigned due to the difficulty in separation of the
complex diastereomers.
Conclusions
General Procedure for the Diels–Alder Reactions
After the solution of 2-vinylindole 1 (0.15 mmol) and cata-
lyst IIIa (0.01 mmol) in dry CH2Cl2 (1 mL) had been stirred
for 5 min at ambient temperature, methyleneindolinone 2
(0.1 mmol) was divided into three portions and added in
five-minute intervals. The solution was stirred for 20 min,
In conclusion, we have developed a bifunctional
squaramide-catalyzed D–A reaction of 2-vinylindoles
and methyleneindolinones. This strategy allows
a rapid and efficient access to diverse and structurally
complex carbazolespirooxindoles with three contigu- then the reaction mixture was directly purified by column
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Organocatalytic Diels–Alder Reaction of 2-Vinylindoles with Methyleneindolinones
chromatography on silica gel (eluted with EtOAc/petroleum
ether) to provide the desired product 3.
7.40 (d, J=7.8 Hz, 1H), 7.37–7.32 (m, 1H), 7.29 (d, J=
8.2 Hz, 1H), 7.20–7.11 (m, 2H), 7.10–6.98 (m, 4H), 6.61 (t,
J=5.9 Hz, 2H), 4.43 (dd, J=10.6, 5.8 Hz, 1H), 4.17 (d, J=
5.1 Hz, 1H), 4.12 (ddd, J=14.3, 9.0, 5.4 Hz, 1H), 3.99 (dq,
J=10.8, 7.1 Hz, 1H), 3.68 (t, J=5.7 Hz, 6H), 3.65–3.57 (m,
1H), 3.26–3.14 (m, 1H), 1.59 (s, 9H), 1.12 (t, J=7.1 Hz,
3H); 13C NMR (100 MHz, CDCl3): d=174.5, 172.3, 158.4,
149.2, 139.4, 137.5, 136.9, 132.0, 129.6, 128.4, 126.4, 125.0,
123.6, 121.0, 119.1, 117.8, 114.4, 113.5, 108.9, 103.5, 84.2,
60.9, 55.1, 52.4, 46.5, 42.8, 31.6, 29.3, 28.1, 14.1; HR-MS
(ESI): m/z=581.2654 [M+H]+, calcd. for [C35H37N2O6]+:
581.2646; [a]2D5: +2.4 (c 1.43, CH2Cl2). The enantiomeric
excess was determined by HPLC with a Chiralpak AD-H
column (hexane/i-PrOH=98/2, 0.8 mL·minÀ1, 230 nm):
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 9-methyl-2’-oxo-2-phenyl-
1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-1’,4-dicar-
boxylate (3a): white solid; mp 182.5–184.88C; 1H NMR
(400 MHz, CDCl3): d=7.58 (d, J=8.2 Hz, 1H), 7.41 (d, J=
7.8 Hz, 1H), 7.35 (d, J=7.6 Hz, 1H), 7.29 (d, J=8.2 Hz,
1H), 7.18 (d, J=7.2 Hz, 1H), 7.15–7.10 (m, 3H), 7.09–7.03
(m, 4H), 7.00 (t, J=7.4 Hz, 1H), 4.50 (dd, J=10.7, 5.8 Hz,
1H), 4.18 (d, J=5.5 Hz, 1H), 4.16–3.95 (m, 2H), 3.76–3.62
(m, 4H), 3.22 (dd, J=16.7, 5.8 Hz, 1H), 1.59 (s, 9H), 1.13 (t,
J=7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3): d=174.4,
172.3, 149.2, 140.0, 139.3, 137.5, 136.9, 128.7, 127.9, 127.1,
126.4, 125.1, 123.6, 121.0, 119.1, 117.8, 114.4, 108.9, 103.5,
84.2, 60.9, 52.2, 46.5, 43.7, 29.3, 28.1, 26.8, 14.1; HR-MS
(ESI): m/z=551.2546 [M+H]+, calcd. for [C34H35N2O5]+:
551.2540; [a]2D5: +7.8 (c 0.90, CH2Cl2). The enantiomeric
excess was determined by HPLC with a Chiralpak AD-H
column (hexane/i-PrOH=98/2, 0.8 mL·minÀ1, 230 nm):
t
major =29.3 min, tminor =13.7 min.
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 2-(3-methoxyphenyl)-9-
methyl-2’-oxo-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3e): white solid; mp 175.8–178.38C;
1H NMR (400 MHz, CDCl3): d=7.61 (d, J=8.1 Hz, 1H),
7.40 (d, J=7.8 Hz, 1H), 7.38–7.32 (m, 1H), 7.29 (d, J=
8.2 Hz, 1H), 7.20–7.11 (m, 2H), 7.07 (d, J=7.0 Hz, 1H),
7.04–6.96 (m, 2H), 6.69 (dd, J=10.0, 4.9 Hz, 2H), 6.60 (dd,
J=8.2, 1.8 Hz, 1H), 4.50 (dd, J=10.8, 5.7 Hz, 1H), 4.20–
4.08 (m, 2H), 4.00 (dq, J=10.9, 7.2 Hz, 1H), 3.70 (s, 3H),
3.68–3.60 (m, 4H), 3.23 (dd, J=16.7, 5.8 Hz, 1H), 1.58 (s,
9H), 1.13 (t, J=7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3):
d=174.8, 171.7, 156.8, 149.4, 139.3, 137.5, 136.8, 128.7, 128.3,
128.1, 126.8, 126.6, 125.0, 123.1, 120.9, 120.5, 119.0, 118.3,
114.1, 110.1, 108.9, 104.0, 84.0, 60.7, 55.1, 52.6, 46.2, 33.8,
29.3, 28.2, 14.0; HR-MS (ESI): m/z=581.2651 [M+H]+,
calcd. for [C35H37N2O6]+: 581.2646; [a]2D5: +7.5 (c 1.24,
CH2Cl2). The enantiomeric excess was determined by HPLC
with a Chiralpak AD-H column (hexane/i-PrOH=98/2,
0.8 mL·minÀ1, 230 nm): tmajor =21.2 min, tminor =16.0 min.
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 2-(2-methoxyphenyl)-9-
methyl-2’-oxo-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3f): white solid; mp 192.9–195.08C;
1H NMR (400 MHz, CDCl3): d=7.65 (d, J=8.0 Hz, 2H),
7.40 (d, J=7.8 Hz, 2H), 7.33 (dd, J=15.5, 7.9 Hz, 4H),
7.21–7.09 (m, 6H), 7.05 (ddd, J=9.0, 5.2, 2.3 Hz, 4H), 6.93
(t, J=7.2 Hz, 2H), 6.71 (t, J=7.4 Hz, 2H), 6.64 (d, J=
8.2 Hz, 2H), 4.20 (s, 2H), 3.96 (ddd, J=28.2, 17.7, 7.0 Hz,
5H), 3.73 (s, 7H), 3.70 (s, 7H), 3.51–3.37 (m, 2H), 3.19 (d,
J=11.0 Hz, 2H), 1.60 (s, 18H), 1.07 (t, J=7.0 Hz, 6H);
13C NMR (100 MHz, CDCl3): d=174.8, 171.7, 156.8, 149.4,
139.3, 137.5, 136.8, 129.1, 127.8, 128.1, 128.1, 126.7, 125.0,
123.1, 120.9, 120.5, 119.0, 118.3, 114.1, 110.1, 108.9, 104.0,
84.0, 60.7, 55.1, 52.6, 46.2, 33.8, 29.5, 29.3, 29.0, 28.1, 26.1,
14.0; HR-MS (ESI): m/z=581.2648 [M+H]+, calcd. for
[C35H37N2O6]+: 581.2646; [a]D25: +4.4 (c 1.03, CH2Cl2). The
enantiomeric excess was determined by HPLC with a Chiral-
pak AD-H column (hexane/i-PrOH=98/2, 0.8 mL·minÀ1,
230 nm): tmajor =28.4 min, tminor =18.5 min.
t
major =16.0 min, tminor =12.3 min.
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 9-benzyl-2’-oxo-2-phenyl-
1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-1’,4-dicar-
boxylate (3b): white solid; mp 178.5–180.38C; 1H NMR
(400 MHz, CDCl3): d=7.58 (d, J=7.8 Hz, 1H), 7.49–7.42
(m, 1H), 7.34 (dd, J=7.7, 0.9 Hz, 1H), 7.29 (t, J=7.3 Hz,
2H), 7.22 (dd, J=7.2, 5.9 Hz, 3H), 7.16–7.10 (m, 2H), 7.10–
7.05 (m, 5H), 7.01 (ddd, J=8.6, 8.0, 2.2 Hz, 4H), 4.50 (dd,
J=10.5, 5.7 Hz, 1H), 4.23 (s, 1H), 4.09 (m, 2H), 3.61 (dd,
J=16.6, 10.7 Hz, 1H), 3.16 (dd, J=16.7, 5.9 Hz, 1H), 1.60
(s, 9H), 1.15 (t, J=7.1 Hz, 3H); 13C NMR (100 MHz,
CDCl3): d=172.7, 170.4, 147.5, 137.6, 135.7, 135.2, 134.8,
127.1, 126.6, 126.6, 124.6, 123.2, 121.8, 119.1, 117.3, 116.0,
112.6, 107.1, 101.7, 82.4, 59.1, 50.4, 44.8, 41.4, 29.8, 27.5, 26.3,
20.8, 12.3; HR-MS (ESI): m/z=627.2859 [M+H]+, calcd.
for [C40H39N2O5]+: 627.2853; [a]D25: +9.1 (c 0.59, CH2Cl2).
The enantiomeric excess was determined by HPLC with
a
Chiralpak AD-H column (hexane/i-PrOH=98/2,
0.8 mL·minÀ1, 230 nm): tmajor =18.7 min, tminor =14.5 min.
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 9-methyl-2’-oxo-2-(para-
tolyl)-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-1’,4-di-
carboxylate (3c): white solid; mp 180.8–185.98C; 1H NMR
(400 MHz, CDCl3): d=7.61 (d, J=8.2 Hz, 1H), 7.40 (d, J=
7.8 Hz, 1H), 7.34 (d, J=7.6 Hz, 1H), 7.29 (d, J=8.2 Hz,
1H), 7.16 (dd, J=17.2, 8.1 Hz, 2H), 7.07 (d, J=7.8 Hz, 1H),
7.05–6.96 (m, 3H), 6.88 (d, J=7.9 Hz, 2H), 4.45 (dd, J=
10.7, 5.8 Hz, 1H), 4.17 (s, 1H), 4.12 (ddd, J=14.3, 9.0,
5.4 Hz, 1H), 3.99 (dq, J=10.8, 7.1 Hz, 1H), 3.69 (s, 3H),
3.67–3.59 (m, 1H), 3.20 (dd, J=16.7, 5.8 Hz, 1H), 2.18 (s,
3H), 1.59 (s, 9H), 1.12 (t, J=7.1 Hz, 3H); 13C NMR
(100 MHz, CDCl3): d=174.4, 172.3, 159.3, 149.2, 141.6,
139.4, 137.5, 136.9, 129.0, 128.5, 128.2, 126.3, 125.1, 123.6,
121.1, 121.0, 119.1, 117.7, 114.4, 113.6, 113.2, 108.9, 103.4,
84.2, 60.9, 55.0, 52.1, 46.7, 43.7, 29.7, 29.4, 28.1, 14.1; HR-MS
(ESI): m/z=565.2695 [M+H]+, calcd. for [C35H37N2O5]+:
565.2697; [a]2D5:+ 3.6 (c 1.21, CH2Cl2). The enantiomeric
excess was determined by HPLC with a Chiralpak AD-H
column (hexane/i-PrOH=98/2, 0.8 mL·minÀ1, 230 nm):
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 2-(4-bromophenyl)-9-
methyl-2’-oxo-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3g): white solid; mp 182.6–186.28C;
1H NMR (400 MHz, CDCl3): d=7.62 (d, J=8.0 Hz, 1H),
7.40 (d, J=7.8 Hz, 1H), 7.35–7.28 (m, 2H), 7.23–7.14 (m,
4H), 7.10–7.06 (m, 1H), 7.05–6.98 (m, 3H), 4.49 (dd, J=
10.6, 5.7 Hz, 1H), 4.17 (d, J=6.8 Hz, 1H), 4.15–3.95 (m,
2H), 3.70 (s, 3H), 3.62 (dd, J=16.6, 10.7 Hz, 1H), 3.20 (dd,
J=16.6, 5.8 Hz, 1H), 1.59 (s, 9H), 1.12 (t, J=7.1 Hz, 3H);
t
major =19.4 min, tminor =9.4 min.
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 2-(4-methoxyphenyl)-9-
methyl-2’-oxo-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3d): white solid; mp180.2–183.48C;
1H NMR (400 MHz, CDCl3): d=7.61 (d, J=7.9 Hz, 1H),
Adv. Synth. Catal. 0000, 000, 0 – 0
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Lin-Jie Huang et al.
13C NMR (100 MHz, CDCl3): d=174.3, 172.1, 149.0, 139.2,
137.5, 136.4, 131.3, 130.3, 128.7, 127.9, 126.3, 124.9, 123.8,
121.1, 119.2, 117.8, 114.6, 109.0, 103.4, 84.5, 61.0, 52.0, 46.5,
43.0, 29.4, 28.1, 26.8, 14.1; HR-MS (ESI): m/z=629.1646
[M+H]+, calcd. for [C34H34BrN2O5]+: 629.1646; [a]2D5: +2.0
(c 1.04, CH2Cl2). The enantiomeric excess was determined
by HPLC with Chiralpak AD-H column (hexane/i-PrOH=
29.4, 28.1, 26.7, 26.5, 14.1; [a]2D5:+3.5 (c 0.96, CH2Cl2); HR-
MS (ESI): m/z=615.2454 calcd. for
[M+Na]+,
[C34H36N2O6Na]+: 615.2466. The enantiomeric excess was de-
termined by HPLC with
a Chiralpak AD-H column
(hexane/i-PrOH=95/5, 0.7 mL·minÀ1, 230 nm): tmajor
28.1 min, tminor =24.1 min.
=
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 2-(4-fluorophenyl)-9-
methyl-2’-oxo-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3k): white solid; mp 183.6–186.68C;
1H NMR (400 MHz, CDCl3): d=7.60 (d, J=8.1 Hz, 1H),
7.41 (d, J=7.7 Hz, 1H), 7.35 (d, J=7.6 Hz, 1H), 7.30 (d, J=
8.2 Hz, 1H), 7.17 (dd, J=15.4, 7.6 Hz, 3H), 7.09–7.06 (m,
2H), 7.01 (d, J=7.6 Hz, 1H), 6.76 (t, J=8.6 Hz, 2H), 4.49
(dd, J=10.5, 5.7 Hz, 1H), 4.13 (ddd, J=14.3, 10.7, 7.2 Hz,
1H), 4.06–3.95 (m, 1H), 3.72 (d, J=21.0 Hz, 3H), 3.63 (dd,
J=16.5, 10.8 Hz, 2H), 3.21 (dd, J=16.6, 5.8 Hz, 1H), 1.59
(s, 9H), 1.12 (t, J=7.1 Hz, 3H); 13C NMR (100 MHz,
CDCl3): d=174.3, 172.2, 149.1, 139.3, 137.5, 136.6, 135.7,
130.1, 128.6, 128.1, 126.3, 125.0, 123.7, 121.1, 119.2, 117.8,
115.2, 115.1, 114.9, 114.5, 109.0, 103.5, 84.4, 60.9, 52.2, 46.4,
42.9, 29.4, 28.1, 26.9, 14.1; HR-MS (ESI): m/z=569.2448
[M+H]+, calcd. for [C34H34FN2O5]+: 569.2446; [a]2D5: +6.8 (c
1.19, CH2Cl2). The enantiomeric excess was determined by
HPLC with a Chiralpak AD-H column (hexane/i-PrOH=
98/2, 0.8 mL·minÀ1, 230 nm):
11.2 min.
tmajor =20.5 min, tminor =
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 2-(4-chlorophenyl)-9-
methyl-2’-oxo-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3h): white solid; mp 182.2–187.38C;
1H NMR (400 MHz, CDCl3): d=7.62 (d, J=8.0 Hz, 1H),
7.40 (d, J=7.8 Hz, 1H), 7.37–7.28 (m, 2H), 7.21–7.13 (m,
2H), 7.10–7.06 (m, 1H), 7.06–7.03 (m, 4H), 7.01 (dd, J=7.6,
0.9 Hz, 1H), 4.50 (dd, J=10.6, 5.8 Hz, 1H), 4.18 (s, 1H),
4.11 (ddd, J=14.3, 9.0, 5.4 Hz, 1H), 3.99 (dq, J=10.8,
7.1 Hz, 1H), 3.70 (s, 3H), 3.62 (dd, J=16.5, 10.8 Hz, 1H),
3.20 (dd, J=16.6, 5.8 Hz, 1H), 1.59 (s, 9H), 1.12 (t, J=
7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3): d=174.3, 172.2,
149.1, 139.3, 138.6, 137.5, 136.5, 132.9, 130.0, 128.7, 128.3,
128.0, 126.3, 125.0, 123.8, 121.1, 119.2, 117.8, 114.5, 109.0,
103.5, 84.4, 61.0, 52.1, 46.5, 43.0, 29.4, 28.1, 26.9, 14.1; [a]2D5:
+5.5 (c 1.27, CH2Cl2); HR-MS (ESI): m/z=585.2145 [M+
H]+, calcd. for [C34H33ClN2O5]+: 585.2151. The enantiomeric
excess was determined by HPLC with a Chiralpak AD-H
column (hexane/i-PrOH=98/2, 0.8 mL·minÀ1, 230 nm):
98/2, 0.8 mL·minÀ1, 230 nm):
10.8 min.
tmajor =16.8 min, tminor =
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 6-methoxy-9-methyl-2’-
oxo-2-phenyl-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3l): white solid; mp 184.9–188.88C;
1H NMR (400 MHz, CDCl3): d=7.58 (d, J=8.1 Hz, 1H),
7.36 (d, J=6.8 Hz, 1H), 7.18 (d, J=8.8 Hz, 1H), 7.15–7.04
(m, 6H), 7.01 (dd, J=8.0, 7.2 Hz, 1H), 6.89 (d, J=2.3 Hz,
1H), 6.82 (dd, J=8.8, 2.4 Hz, 1H), 4.51 (dd, J=10.9, 5.8 Hz,
1H), 4.21–4.11 (m, 2H), 4.00 (dq, J=10.8, 7.1 Hz, 1H), 3.81
(s, 3H), 3.70–3.60 (m, 4H), 3.20 (dd, J=16.7, 5.8 Hz, 1H),
1.59 (s, 9H), 1.15 (t, J=7.1 Hz, 3H); 13C NMR (100 MHz,
CDCl3): d=174.4, 172.3, 153.9, 149.2, 140.0, 139.3, 137.5,
132.8, 128.8, 128.0, 127.1, 126.6, 125.1, 123.7, 114.4, 110.5,
109.6, 103.1, 100.5, 84.2, 60.9, 55.9, 52.2, 46.6, 43.6, 29.5, 28.1,
26.9, 14.2; HR-MS (ESI): m/z=581.2647 [M+H]+, calcd.
for [C35H37N2O6]+: 581.2646; [a]D25: +4.2 (c 1.74, CH2Cl2).
The enantiomeric excess was determined by HPLC with
t
major =19.4 min, tminor =10.9 min.
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 2-(4-cyanophenyl)-9-
methyl-2’-oxo-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3i): white solid; mp 190.1–194.28C;
1H NMR (400 MHz, CDCl3): d=7.63 (dd, J=8.3, 1.0 Hz,
1H), 7.44 (dt, J=7.8, 1.0 Hz, 1H), 7.43–7.38 (m, 2H), 7.35
(ddd, J=10.1, 8.0, 1.1 Hz, 2H), 7.28 (d, J=5.3 Hz, 1H), 7.11
(ddd, J=8.0, 7.1, 1.0 Hz, 1H), 7.05 (td, J=7.6, 1.1 Hz, 1H),
4.61 (dd, J=10.0, 5.6 Hz, 1H), 4.23 (s, 1H), 4.15 (dq, J=
10.9, 7.2 Hz, 1H), 4.03 (dq, J=10.8, 7.1 Hz, 1H), 3.73 (s,
3H), 3.66 (dd, J=16.5, 10.6 Hz, 1H), 3.25 (dd, J=16.6,
5.9 Hz, 1H), 1.62 (s, 9H), 1.15 (t, J=7.1 Hz, 3H); 13C NMR
(101 MHz, CDCl3): d=174.0, 172.0, 145.6, 139.1, 137.4,
135.8, 131.9, 129.4, 128.9, 127.5, 124.9, 123.9, 121.2, 119.3,
117.9, 114.6, 109.0, 103.4, 84.7, 61.0, 51.9, 46.3, 43.7, 29.4,
28.1, 26.4, 14.0; [a]D25:+3.3 (c 0.91, CH2Cl2); HR-MS (ESI):
m/z=598.2293 [M+Na]+, calcd. for [C35H33N3O5Na]+:
598.2312. The enantiomeric excess was determined by
HPLC with a Chiralpak AD-H column (hexane/i-PrOH=
a
Chiralpak AD-H column (hexane/i-PrOH=98/2,
0.8 mL·minÀ1, 230 nm): tmajor =37.0 min, tminor =23.8 min.
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 5’-fluoro-9-methyl-2’-oxo-
2-phenyl-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-
1’,4-dicarboxylate (3m): white solid; mp 192.2–194.58C;
1H NMR (400 MHz, CDCl3): d=7.57 (dd, J=9.0, 4.8 Hz,
1H), 7.41 (d, J=7.8 Hz, 1H), 7.30 (d, J=8.2 Hz, 1H), 7.19
(d, J=7.1 Hz, 1H), 7.15 (dd, J=5.9, 1.9 Hz, 1H), 7.13–7.08
(m, 5H), 7.06 (d, J=7.0 Hz, 1H), 6.83 (td, J=8.9, 2.7 Hz,
1H), 4.49 (dd, J=10.9, 5.8 Hz, 1H), 4.18 (s, 1H), 4.17–4.03
(m, 2H), 3.70 (s, 3H), 3.68–3.61 (m, 1H), 3.22 (dd, J=16.7,
5.8 Hz, 1H), 1.58 (s, 9H), 1.17 (t, J=7.1 Hz, 3H); 13C NMR
(100 MHz, CDCl3): d=173.9, 172.1, 160.6, 149.1, 139.6,
136.7, 130.5, 130.3, 130.1, 128.5, 128.2, 127.3, 126.2, 121.1,
119.2, 117.7, 115.6, 114.8, 112.5, 109.0, 103.2, 84.4, 61.1, 52.4,
46.4, 43.7, 29.4, 28.1, 26.8, 14.1; HR-MS (ESI): m/z=
591.2270 [M+H]+, calcd. for [C34H34FN2O5]+: 591.2266;
[a]2D5: +4.3 (c 0.46, CH2Cl2). The enantiomeric excess was
determined by HPLC with a Chiralpak AD-H column
95/5, 0.7 mL·minÀ1, 230 nm):
20.7 min.
tmajor =27.2 min, tminor =
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 2-(4-acetylphenyl)-9-
methyl-2’-oxo-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3j): white solid; mp 185.2–189.58C;
1H NMR (400 MHz, CDCl3): d=7.70–7.65 (m, 2H), 7.60
(dd, J=8.2, 1.0 Hz, 1H), 7.41 (dt, J=7.8, 1.0 Hz, 1H), 7.33
(ddd, J=17.5, 8.0, 1.1 Hz, 2H), 7.25–7.12 (m, 4H), 7.07
(ddd, J=8.0, 7.1, 1.0 Hz, 1H), 7.01 (td, J=7.6, 1.1 Hz, 1H),
4.61 (dd, J=10.6, 5.8 Hz, 1H), 4.20 (s, 1H), 4.13 (dq, J=
10.8, 7.1 Hz, 1H), 4.00 (dq, J=10.8, 7.1 Hz, 1H), 3.70 (s,
3H), 3.69–3.63 (m, 1H), 3.22 (dd, J=16.6, 5.8 Hz, 1H), 2.49
(s, 3H), 1.60 (s, 9H), 1.12 (t, J=7.1 Hz, 3H); 13C NMR
(101 MHz, CDCl3): d=172.1, 145.7, 139.2, 137.4, 136.3,
135.9, 128.8, 128.7, 128.2, 127.7, 126.2, 124.9, 123.8, 121.1,
119.2, 117.8, 114.5, 109.0, 103.4, 84.5, 61.0, 51.9, 46.5, 43.5,
8
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ÝÝ
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FULL PAPERS
Organocatalytic Diels–Alder Reaction of 2-Vinylindoles with Methyleneindolinones
(hexane/i-PrOH=98/2, 0.8 mL·minÀ1, 230 nm): tmajor
23.6 min, tminor =13.0 min.
=
2.7 Hz, 2H), 7.14–7.08 (m, 4H), 6.91 (d, J=2.3 Hz, 1H),
6.84 (dtd, J=7.0, 4.6, 2.8 Hz, 2H), 4.51 (dd, J=11.0, 5.8 Hz,
1H), 4.25–4.04 (m, 3H), 3.82 (s, 3H), 3.74–3.58 (m, 4H),
3.21 (dd, J=16.7, 5.8 Hz, 1H), 1.60 (s, 9H), 1.21 (t, J=
9.3 Hz, 3H); 13C NMR (100 MHz, CDCl3): d=173.9, 172.1,
153.9, 149.1, 139.5, 137.3, 132.8, 128.5, 128.2, 127.3, 126.5,
115.7, 115.0, 114.8, 112.8, 112.6, 110.6, 109.6, 102.8, 100.5,
84.4, 61.1, 55.9, 52.4, 46.4, 43.6, 29.5, 28.1, 26.9, 14.3; HR-MS
(ESI): m/z=599.2556 [M+H]+, calcd. for [C35H36FN2O6]+:
599.2552; [a]2D5: À1.6 (c 0.68, CH2Cl2). The enantiomeric
excess was determined by HPLC with a Chiralpak AD-H
column (hexane/i-PrOH=98/2, 0.8 mL·minÀ1, 230 nm):
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 5’-chloro-9-methyl-2’-oxo-
2-phenyl-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-
1’,4-dicarboxylate (3n): white solid; mp 186.3–188.48C;
1H NMR (400 MHz, CDCl3): d=7.54 (d, J=8.7 Hz, 1H),
7.40 (d, J=7.8 Hz, 1H), 7.36 (d, J=2.2 Hz, 1H), 7.30 (d, J=
8.2 Hz, 1H), 7.22–7.14 (m, 1H), 7.11 (d, J=4.0 Hz, 4H),
7.09 (d, J=2.5 Hz, 2H), 7.06 (d, J=7.1 Hz, 1H), 4.48 (dd,
J=10.9, 5.8 Hz, 1H), 4.17 (d, J=5.8 Hz, 1H), 4.16–4.07 (m,
2H), 3.70 (s, 3H), 3.67–3.60 (m, 1H), 3.23 (dd, J=16.7,
5.8 Hz, 1H), 1.58 (s, 9H), 1.18 (t, J=7.1 Hz, 3H); 13C NMR
(100 MHz, CDCl3): d=173.6, 172.1, 149.0, 139.5, 137.9,
137.4, 136.7, 130.9, 130.1, 129.3, 128.8, 128.7, 127.3, 126.2,
125.2, 124.5, 121.1, 119.2, 117.7, 115.6, 109.0, 103.2, 84.6,
61.2, 52.3, 46.4, 43.6, 29.4, 28.1, 26.7, 14.2; HR-MS (ESI):
m/z=585.2154 [M+H]+, calcd. for [C34H34ClN2O5]+:
585.2151; [a]2D5: +5.7 (c 0.28, CH2Cl2). The enantiomeric
excess was determined by HPLC with a Chiralpak AD-H
column (hexane/i-PrOH=98/2, 0.8 mL·minÀ1, 230 nm):
t
major =20.8 min, tminor =11.8 min.
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 6-methoxy-5’,9-dimethyl-
2’-oxo-2-phenyl-1,2,4,9-tetrahydrospiro [carbazole-3,3’-indo-
line]-1’,4-dicarboxylate (3r): white solid; mp 182.0–185.68C;
1H NMR (400 MHz, CDCl3): d=7.45 (d, J=8.3 Hz, 1H),
7.21–7.14 (m, 2H), 7.11 (dd, J=7.5, 2.3 Hz, 2H), 7.09–7.02
(m, 3H), 6.92 (dd, J=8.3, 1.1 Hz, 1H), 6.88 (d, J=2.3 Hz,
1H), 6.82 (dd, J=8.8, 2.4 Hz, 1H), 4.47 (dd, J=10.8, 5.8 Hz,
1H), 4.21–4.09 (m, 2H), 4.02 (dq, J=10.8, 7.1 Hz, 1H), 3.81
(s, 3H), 3.67 (d, J=5.4 Hz, 3H), 3.66–3.58 (m, 1H), 3.19
(dd, J=16.7, 5.8 Hz, 1H), 2.26 (s, 3H), 1.58 (s, 9H), 1.15 (t,
J=7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3): d=174.6,
172.3, 153.9, 149.2, 140.1, 137.6, 136.9, 133.1, 132.8, 130.9,
128.8, 128.6, 128.1, 127.1, 126.6, 125.5, 114.1, 110.4, 109.6,
103.2, 100.5, 84.0, 60.8, 55.9, 52.2, 46.6, 43.6, 29.5, 28.1, 27.0,
21.1, 14.2; HR-MS (ESI): m/z=617.2626 [M+H]+, calcd.
for [C36H39N2NaO6]+: 617.2622; [a]25: +5.4 (c 1.38, CH2Cl2).
The enantiomeric excess was detDermined by HPLC with
t
major =26.7 min, tminor =12.4 min.
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 5’-bromo-9-methyl-2’-oxo-
2-phenyl-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-
1’,4-dicarboxylate (3o): white solid; mp 185.8–187.78C;
1H NMR (400 MHz, CDCl3): d=7.52–7.46 (m, 2H), 7.40 (d,
J=7.8 Hz, 1H), 7.30 (d, J=8.2 Hz, 1H), 7.25 (dd, J=8.7,
2.0 Hz, 1H), 7.17 (dd, J=11.2, 4.0 Hz, 1H), 7.10 (d, J=
3.8 Hz, 4H), 7.09–7.04 (m, 2H), 4.47 (dd, J=10.9, 5.8 Hz,
1H), 4.21–4.05 (m, 3H), 3.70 (s, 3H), 3.68–3.59 (m, 1H),
3.23 (dd, J=16.7, 5.8 Hz, 1H), 1.58 (s, 9H), 1.19 (t, J=
7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3): d=173.5, 172.2,
149.0, 139.4, 138.4, 137.4, 136.7, 131.3, 130.4, 129.9, 128.5,
128.3, 128.0, 127.3, 126.2, 121.1, 119.2, 117.6, 116.7, 116.1,
109.0, 103.1, 84.6, 61.2, 52.2, 46.4, 43.6, 29.4, 28.1, 26.7, 14.2;
HR-MS (ESI): m/z=629.1649 [M+H]+, calcd. for
[C34H34BrN2O5]+: 629.1646; [a]D25: +4.1 (c 0.54, CH2Cl2). The
enantiomeric excess was determined by HPLC with a Chiral-
pak AD-H column (hexane/i-PrOH=98/2, 0.8 mL·minÀ1,
230 nm): tmajor =29.5 min, tminor =12.8 min.
a
Chiralpak AD-H column (hexane/i-PrOH=98/2,
0.8 mL·minÀ1, 230 nm): tmajor =43.0 min, tminor =22.1 min.
(2S,3R,4R)-1’-tert-Butyl 4-methyl 9-methyl-2’-oxo-2-
phenyl-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-1’,4-
1
dicarboxylate (3s): white solid; mp 182.0–185.68C; H NMR
(400 MHz, CDCl3): d=7.58 (d, J=8.2 Hz, 1H), 7.38 (d, J=
7.8 Hz, 1H), 7.30 (dd, J=5.3, 3.9 Hz, 2H), 7.20–7.14 (m,
1H), 7.11 (dd, J=7.9, 6.3 Hz, 3H), 7.10–7.03 (m, 4H), 7.01
(dd, J=7.6, 1.0 Hz, 1H), 4.48 (dd, J=11.0, 5.7 Hz, 1H), 4.21
(s, 1H), 3.77–3.64 (m, 4H), 3.61 (s, 3H), 3.23 (dd, J=16.7,
5.8 Hz, 1H), 1.59 (s, 9H); 13C NMR (101 MHz, CDCl3): d=
174.4, 172.8, 167.7, 149.1, 139.8, 139.3, 137.4, 136.9, 132.3,
130.9, 128.8, 128.5, 128.1, 127.1, 126.3, 124.7, 123.7, 121.0,
119.2, 117.6, 114.5, 109.0, 103.3, 84.3, 65.6, 51.8, 46.6, 43.7,
30.6, 29.4, 28.1; HR-MS (ESI): m/z=537.2383 [M+H]+,
calcd. for [C33H33N2O5]+: 537.2384; [a]2D5: +5.4 (c 1.38,
CH2Cl2). The enantiomeric excess was determined by HPLC
with a Chiralpak AD-H column (hexane/i-PrOH=98/2,
0.8 mL·minÀ1, 230 nm): tmajor =43.1 min, tminor =22.5 min.
tert-Butyl (2S,3R,4R)-4-benzoyl-9-methyl-2’-oxo-2-phenyl-
1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-1’-carboxyla-
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 5’,9-dimethyl-2’-oxo-2-
phenyl-1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-1’,4-
1
dicarboxylate (3p): white solid; mp 182.8–184.78C; H NMR
(400 MHz, CDCl3): d=7.46 (d, J=8.3 Hz, 1H), 7.39 (d, J=
7.8 Hz, 1H), 7.30 (d, J=8.2 Hz, 1H), 7.20–7.13 (m, 2H),
7.13–7.02 (m, 6H), 6.93 (dd, J=8.3, 1.1 Hz, 1H), 4.46 (dd,
J=10.7, 5.8 Hz, 1H), 4.15 (d, J=7.6 Hz, 1H), 4.15–3.97 (m,
2H), 3.70 (s, 3H), 3.68–3.61 (m, 1H), 3.22 (dd, J=16.6,
5.8 Hz, 1H), 2.26 (s, 3H), 1.58 (s, 9H), 1.13 (t, J=7.1 Hz,
3H); 13C NMR (100 MHz, CDCl3): d=174.6, 172.3, 149.2,
140.1, 137.4, 136.9, 133.1, 128.8, 128.6, 128.1, 127.1, 126.4,
125.5, 121.0, 119.1, 117.7, 114.2, 108.9, 103.6, 84.0, 60.8, 52.2,
46.6, 43.7, 29.3, 28.1, 26.9, 21.1, 14.1; HR-MS (ESI): m/z=
587.2517 [M+H]+, calcd. for [C35H37N2O5]+: 587.2516; [a]D25:
+6.8 (c 1.00, CH2Cl2). The enantiomeric excess was deter-
mined by HPLC with a Chiralpak AD-H column (hexane/i-
1
te(3t): white solid; mp 198.1–203.38C; H NMR (400 MHz,
CDCl3): d=7.67–7.60 (m, 2H), 7.55–7.45 (m, 2H), 7.37–7.30
(m, 2H), 7.27 (s, 1H), 7.17–7.11 (m, 2H), 7.10–7.02 (m, 5H),
6.95 (td, J=7.9, 1.3 Hz, 1H), 6.85–6.76 (m, 2H), 6.69 (td, J=
7.6, 1.1 Hz, 1H), 5.29 (s, 1H), 4.62 (dd, J=11.2, 5.7 Hz, 1H),
3.79–3.73 (m, 1H), 3.72 (s, 3H), 3.31 (dd, J=16.7, 5.8 Hz,
1H), 1.62 (s, 9H); 13C NMR (101 MHz, CDCl3): d=201.4,
139.7, 138.5, 137.3, 137.2, 133.0, 128.7, 128.5, 128.3, 128.2,
128.0, 127.5, 127.1, 126.0, 123.6, 120.8, 118.8, 117.4, 114.2,
108.9, 104.7, 84.3, 52.8, 45.6, 43.9, 29.4, 28.1, 26.8; [a]2D5: +4.0
(c 1.01, CH2Cl2); HR.MS (ESI): m/z=583.2567 [M+H]+,
PrOH=98/2, 0.8 mL·minÀ1, 230 nm): tmajor =18.6 min, tminor
11.3 min.
=
(2S,3R,4R)-1’-tert-Butyl 4-ethyl 5’-fluoro-6-methoxy-9-
methyl-2’-oxo-2-phenyl-1,2,4,9-tetrahydrospiro [carbazole-
3,3’-indoline]-1’,4-dicarboxylate (3q): white solid; mp 177.2–
1
181.18C; H NMR (400 MHz, CDCl3): d=7.58 (dd, J=9.0,
4.7 Hz, 1H), 7.20 (d, J=8.8 Hz, 1H), 7.16 (dd, J=8.7,
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Lin-Jie Huang et al.
calcd. for [C38H35N2O4]+: 583.2519. The enantiomeric excess
was determined by HPLC with a Chiralcel OD-H column
metric synthesis of spirooxindoles, see: g) Y. Wang, F.
Shi, X.-X. Yao, M. Sun, L. Dong, S.-J. Tu, Chem. Eur. J.
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(hexane/i-PrOH=95/5, 0.5 mL·minÀ1, 230 nm): tmajor
24.7 min, tminor =18.6 min.
=
tert-Butyl (2S,3R,4R)-4-cyano-9-methyl-2’-oxo-2-phenyl-
1,2,4,9-tetrahydrospiro[carbazole-3,3’-indoline]-1’-carboxyl-
ate (3u): white solid; mp 180.1–184.68C; 1H NMR
(400 MHz, CDCl3): d=7.67 (dd, J=7.8, 1.3 Hz, 1H), 7.64–
7.60 (m, 1H), 7.56 (dt, J=7.7, 1.0 Hz, 1H), 7.36 (dt, J=8.2,
0.9 Hz, 1H), 7.26 (d, J=0.8 Hz, 3H), 7.23–7.19 (m, 1H),
7.18–7.15 (m, 1H), 7.15–7.10 (m, 3H), 7.07 (dd, J=6.8,
3.1 Hz, 2H), 4.42 (s, 1H), 3.86 (dd, J=9.8, 5.8 Hz, 1H), 3.72
(s, 3H), 3.62 (dd, J=17.0, 9.8 Hz, 1H), 3.24 (dd, J=16.9,
5.8 Hz, 1H), 1.60 (s, 9H); 13C NMR (101 MHz, CDCl3): d=
139.0, 138.5, 137.5, 136.1, 129.2, 128.3, 128.1, 127.6, 126.8,
125.6, 124.1, 121.8, 119.9, 118.0, 117.5, 114.4, 109.2, 100.1,
84.6, 51.2, 45.8, 33.0, 29.4, 28.0, 26.6; HR-MS (ESI): m/z=
504.2272 [M+H]+, calcd. for [C32H30N3O3]+: 504.2209. The
enantiomeric excess was determined by HPLC with a Chiral-
pak IA column (hexane/i-PrOH=95/5, 0.5 mL·minÀ1,
230 nm): tmajor =22.8 min, tminor =14.5 min.
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Acknowledgements
This work was financially supported by The National High-
tech R&D Program of China (No. 2013AA092903), The In-
troduction of Innovative R&D Team Program of Guangdong
Province (No. 2009010058), the Guangdong Natural Science
Foundation (No. S2013040012409), the Fundamental Re-
search Funds for the Central Universities (No. 12ykpy10) and
Guangdong Provincial Key Laboratory of Construction
Foundation (2011A060901014).
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12 Organocatalytic Diels–Alder Reaction of 2-Vinylindoles
with Methyleneindolinones: An Efficient Approach to
Functionalized Carbazolespirooxindoles
Adv. Synth. Catal. 2015, 357, 1 – 12
Lin-Jie Huang, Jiang Weng,* Sheng Wang, Gui Lu*
12
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