Highly efficient and stereoselective construction of bispirooxindole derivatives via a three-component 1,3-dipolar cycloaddition reaction

Article abstract of DOI:10.1002/open.201402003

A highly regio- and stereoselective synthesis of bispirooxindoles by 1,3-dipolar cycloaddition of in situ generated azomethine ylides from isatin and proline to different electron-deficient alkenes has been developed. The synthesis affords the desired bispiro scaffold compounds in excellent yields with high regioselectivity under mild conditions. The stereochemistry was determined by single-crystal X-ray analysis.

Full text of DOI:10.1002/open.201402003

DOI: 10.1002/open.201402003
Highly Efficient and Stereoselective Construction of
Bispirooxindole Derivatives via a Three-Component
1,3-Dipolar Cycloaddition Reaction
Qin Xu,[a] De Wang,[a] Yin Wei,[b] and Min Shi*[a, b]
A highly regio- and stereoselective synthesis of bispirooxin-
doles by 1,3-dipolar cycloaddition of in situ generated azome-
thine ylides from isatin and proline to different electron-defi-
cient alkenes has been developed. The synthesis affords the
desired bispiro scaffold compounds in excellent yields with
high regioselectivity under mild conditions. The stereochemis-
try was determined by single-crystal X-ray analysis.
Introduction
The development of highly effi-
cient methods to construct spiro
compounds have been a hot
topic of great relevance in or-
ganic synthesis due to the pro-
nounced biological activities of
this class of compounds.[1] In
particular, the spirooxindole ring
systems, which widely exist in
Figure 1. Examples of biologically active spirooxindole derivatives.
a variety of natural and unnatu-
ral products, are attractive syn-
thetic targets.[2,3] Recently, significant research efforts have
been focused on the strategy for construction of spiro 3,3’-cy-
clooxindoles in medicinal and agricultural chemistry due to
their unique biological activity, such as spiro 3,3’-cyclooxin-
doles A, B, C and D (Figure 1).[4] A variety of synthetic methods
have been developed to access analogous compounds pos-
sessing the spirocyclic oxindole skeleton at the C3 position of
the oxindole core.[4] Moreover, the fusion of oxindole motifs
with different heterocycles or heteroatoms for the formation of
diverse spirocyclic oxindoles have also attracted significant at-
tention.[5]
Among the strategies for the construction of the framework
of spirooxindoles,[6] it was noticed that 1,3-dipolar cycloaddi-
tion of azomethine ylides, generated from the decarboxylative
condensation of isatins with different amino acid, to various
olefins represented an efficient method for the construction of
spiro-fused oxindoles involving the pyrrolidine moiety
(Scheme 1).[7,8] Great efforts have been made towards the
[3+2] cycloaddition of azomethine ylides generated from isatin
with different olefins.[9,10] This methodology is fascinating be-
cause it provides an efficient method to construct five-mem-
bered heterocycles. Furthermore, when the electron-deficient
alkene is a trisubstituted cyclic compound, the bispiro product
would be obtained. A few excellent examples have been re-
ported for the construction of bispirooxindoles.[11] It is worth
noting that Xie and Wang’s group have reported the construc-
tion of spiropyrrolidine bisoxindoles via 1,3-dipolar cycloaddi-
tion reaction. However, the stereochemistry of bispirooxindoles
have not yet been determined when applying cyclic amino
acids.11c The reactivities of this 1,3-dipolar cycloaddition reac-
tion to construct bispirooxindoles still need to be carefully and
systematically studied, and the relative configuration of many
of them still need to be resolved. In this paper, we wish to
report a highly regio- and stereoselective synthesis of densely
functionalized bispirooxindole analogues via a three-compo-
nent 1,3-dipolar cycloaddition reaction of in situ generated
azomethine ylides from isatin and proline to different electron-
deficient trisubstituted cyclic olefins under mild conditions.
[a] Dr. Q. Xu, D. Wang, Prof. Dr. M. Shi
Key Laboratory for Advanced Materials and Institute of Fine Chemicals
School of Chemistry & Molecular Engineering
East China University of Science and Technology
130 Mei Long Road, Shanghai 200237 (P. R. China)
[b] Dr. Y. Wei, Prof. Dr. M. Shi
State Key Laboratory of Organometallic Chemistry
Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences
345 Lingling Road, Shanghai 200032 (P. R. China)
E-mail: Mshi@mail.sioc.ac.cn
Supporting information for this article is available on the WWW under
http://dx.doi.org/10.1002/open.201402003.
ꢀ 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
This is an open access article under the terms of the Creative Commons
Attribution-NonCommercial-NoDerivs License, which permits use and
distribution in any medium, provided the original work is properly cited,
the use is non-commercial and no modifications or adaptations are
made.
ꢀ 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemistryOpen 2014, 3, 93 – 98 93

www.chemistryopen.org
in Figure 2A (CIF data are sum-
marized in the Supporting Infor-
mation).
With the identification of the
optimal reaction conditions, the
generality of this three-compo-
nent 1,3-dipolar cycloaddition re-
action was examined using a va-
riety of isatines 1 and isatin-de-
rived electron-deficient alkenes
Scheme 1. The reaction model of the decarboxylative condensation of isatin with different amino acid.
2. The results are summarized in Table 2. All reactions proceed-
ed smoothly to give the corresponding products 3 in moder-
ate to good yields with excellent stereoselectivities under the
optimal conditions (Table 2). Good yields and excellent stereo-
selectivities were obtained when utilizing electron-deficient ox-
indole alkenes 2b–f as the substrates because regardless of
whether R3 is an electron-donating or -withdrawing substituent
on the aromatic ring, the reactions proceeded smoothly to
Results and Discussion
Initial examination was carried out using N-benzyl-protected
isatin 1a (0.1 mmol), l-proline (0.12 mmol) and (E)-ethyl 2-(1-
benzyl-2-oxoindolin-3-ylidene)acetate 2a (0.12 mmol) as the
substrates in methanol at 608C for 2 h to determine the reac-
tion outcome (Table 1, Entry 1). We found that the desired cy-
Table 1. Optimization of the reaction conditions of the three-component
1,3-dipolar cycloaddition.
Entry[a]
Solvent
T [oC]
d.r.[b]
Yield [%][c]
1
2
3
4
5
6
7
8
9
MeOH
Actone
CH3CN
Toluene
EtOH
EtOH
EtOH
EtOH
EtOH
60
60
60
60
60
50
40
30
20
>99:1
–
67
trace
51
20
96
96
92
92
92
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
[a] All reaction was carried out with 1a (0.1 mmol), l-proline (0.12 mmol),
2a (0.1 mmol) in solvent (1.0 mL) in 2 h; [b] Determined by 1H NMR spec-
troscopy; [c] Isolated yield.
cloadduct 3a was obtained in 67% yield with >99:1 diastereo-
meric ratio (d.r.). Subsequently, we attempted to optimize the
reaction conditions by screening solvents, and the results are
summarized in Table 1 (Entries 2–5). As depicted in Table 1, the
employed solvent had a significant influence on the reaction
outcome. Using acetonitrile or toluene as the solvent, the yield
of desired product 3a decreased to 51% or 20%, respectively
(Entries 2, 3). The reaction could not take place in acetone
(Entry 4). Using ethanol as the solvent, the yield of 3a was in-
creased to 96% along with excellent diastereoselectivities
(Entry 5). Therefore, ethanol was the most suitable solvent for
this reaction. Lowering the reaction temperature to 508C,
408C, 308C or room temperature (208C), the reaction proceed-
ed smoothly, and the yield of 3a slightly decreased to 92%
(Table 1, Entries 6–9). The stereochemistry of 3a were deter-
mined by X-ray analysis and the ORTEP drawing is presented
Figure 2. The X-ray crystal structures of 3a and 5g.
ChemistryOpen 2014, 3, 93 – 98 94
ꢀ 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemistryopen.org
electron-deficient or electron-rich aromatic ring of
4a–4e (R5 =H, 6-Br, 7-Br, 5-Cl or 5-CH3) with 1a and
l-proline, providing a series of the desired products
5a–e in 75–93% yields with excellent diastereoselec-
tivities (Table 3, Entries 1–5). Switching the electron-
withdrawing group to benzoyl, cyano, benzyl ester or
a phenyl group, the corresponding products were
obtained in 80-99% yields (Table 3, Entries 6–9). The
stereochemical outcome of this cycloaddition was
determined by single-crystal X-ray analysis of bispiro-
oxindole 5g. The ORTEP drawing is shown in Fig-
ure 2B (CIF data are summarized in the Supporting
Information).
Table 2. Substrate scope of the three-component 1,3-dipolar cycloaddition reaction of
1, l-proline and 2.
Entry[a]
1 [R1/R2]
2 [R4/R3]
d.r.[b]
3 Yield [%][c]
1
2
3
4
5
6
7
8
1a (H/Bn)
1a (H/Bn)
1a (H/Bn)
1a (H/Bn)
2b (5-CH3/Bn)
2c (7-CH3/Bn)
2d (6-OCH3/Bn)
2e (7-OCH3/Bn)
2 f (5-Cl/Bn)
2a (H/Bn)
2a (H/Bn)
2a (H/Bn)
2a (H/Bn)
2a (H/Bn)
2g (H/allyl)
2h (H/H)
2i (H/CH3)
2a (H/Bn)
2a (H/Bn)
2j (H/allyl)
2a (H/Bn)
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
–
3b: 87
3c:90
3d: 69
3e: 72
3 f: 81
3g: 72
3h: 68
3i: 73
3j: 81
3k: 83
3l: 89
3m: 98
3n: 87
3o: 83
3p: 85
3q: 99
NR[f]
1a (H/Bn)
1b (5-CH3/Bn)d
1c (6-CH3/Bn)d
1d (7-CH3/Bn)d
1e (5-F/Bn)
1 f (5-Br/Bn)
1a (H/Bn)
We also investigated l-pipecolic acid or sarcrosine
instead of l-proline in this reaction. The desired bis-
piro product could be obtained in almost quantita-
tive yield with single stereoisomer (up to 99% yield
and >19:1 d.r.), respectively (Scheme 2A and 2B). En-
larging the reaction scale to 5.0 mmol afforded 3a
and 5g in 92% and 90% yields, respectively, under
the standard conditions (Scheme 2B).
9
10
11
12
13
14
15
16
17
1a (H/Bn)
1a (H/Bn)
1g (H/CH3)
1h (H/9-anthmethyl)e
1i (H/allyl)
Subsequently, we applied electron-deficient al-
kenes 8, which have similar structural motifs as 4, in
this three-component 1,3-dipolar cycloaddition reac-
tion. The results are summarized in Scheme 3. Re-
gardless of whether R1 or R2 is an electron-rich or
electron-deficient aromatic ring, the reactions pro-
ceeded smoothly to give the [3+2] annulation prod-
1j (4-Br/Bn)
[a]All reactions were carried out with 1 (0.1 mmol), l-proline (0.12 mmol), 2 (0.1 mmol)
in ethanol at 508C; [b] Determined by 1H NMR analysis of crude products. [c] Isolated
yield. [d] For 24 h. [e] 9-Anthmethyl=9-anthracenemethyl. [f] NR=no reaction.
give the corresponding bispirooxindole products 3b–f in good
yields (69–90%) with excellent stereoslectivities (single isomer)
(Table 2, Entries 1–5). Meanwhile, different substituents on the
aromatic ring of isatin 1 did not impact the yield of 3 signifi-
cantly (Table 2, Entries 6–10). Substrates with electron-donating
substituent on the aromatic ring of isatins produced 3 in mod-
erate yields (68–73%) upon prolonging the reaction time to
24 h (entries 6–8). The yields of 3 decreased slightly using sub-
strates with electron-withdrawing substituents on the
ucts in 75–94% yields along with >99:1 d.r. values (Scheme 3).
The stereochemistries of compounds 9 have not yet been de-
termined, since these compounds gradually decomposed
during recrystallization.
We next utilize this methodology to alkene 10 derived from
piperidine and alkylidene azlactone 12. As results, the corre-
sponding products 11 were obtained in 92% and 67% yields
as single stereoisomer, respectively (Scheme 4A and 4B). The
aromatic ring (Entries 9–10). Experiments with differ-
Table 3. Substrate scope of the three-component 1,3-dipolar cycloaddition reaction
of 1a, l-proline and 4.
ent protecting groups at the nitrogen atoms of 1 or
2 were also conducted. To our delight, with these dif-
ferent protecting groups such as allyl, methyl, 9-an-
thracenemethyl or without protecting group, the re-
actions proceeded efficiently, affording the corre-
sponding products in 73–99% yield with >99:1 d.r.
(Entries 11–16). It should be noted that using isatin
1k having a R1 substituent at the C4 position, the
three-component 1,3-dipolar cycloaddition could not
give the corresponding product, perhaps due to
a steric effect (Table 2, Entry 17).
Entry[a]
4 (EWG/R5/R6)
d.r.[b]
5 Yield [%][c]
1
2
3
4
5
6
7
8
9
4a (COCH3/H/Bn)
4b (COCH3/5-CH3/Bn)
4c (COCH3/6-Br/Bn)
4d (COCH3/7-Br/Bn)
4e (COCH3/5-Cl/Bn)
4 f (COPh/5-F/Bn)
4g (CN/H/Bn)
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
>99:1
5a: 93
5b: 83
5c: 75
5d: 78
5e: 82
5 f: 99
5g: 91
5h: 84
5i: 80
Instead of 2, we next attempted to use various
isatin-derived electron-deficient alkenes 4 to examine
the reaction outcome. Gratefully, we found that the
reactions also proceeded smoothly to give the annu-
lation products in high yields with high diastereose-
lectivities. The results are summarized in Table 3.
Changing the electron-withdrawing group to an
acetyl group, the reaction was also tolerant to an
4h (CO2Bn/H/Bn)
4i (Ph/H/H)
[a] All reaction was carried out with 1a (0.1 mmol), l-proline (0.12 mmol), 2a
(0.1 mmol) in ethanol (1.0 mL) for 2 h; [b] Determined by crude product 1H NMR spec-
troscopy; [c] Isolated yield by column chromatography.
ꢀ 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemistryOpen 2014, 3, 93 – 98 95

www.chemistryopen.org
Conclusions
In conclusion, we have synthe-
sized a series of bispirooxindole
compounds via a three-compo-
nent 1,3-dipolar cycloaddition re-
action with respect to a variety
of different alkenes, affording
the corresponding bispirooxin-
doles in moderate to good
yields (up to >99%) and excel-
lent diastereoselectivities (as
single isomer in most cases)
under mild conditions. Current
efforts focusing on the asymmet-
ric version of this reaction and
applying this methodology to
synthesize biologically active
products are also in progress.
Scheme 2. Three-component 1,3-dipolar cycloaddition reaction A) with l-pipecolic acid, B) with sarcrosine and
Experimental Section
C) performed in large scale.
General
1
procedure:
(0.10 mmol),
Isatin
l-proline
(0.12 mmol) and electron-deficient
olefin (0.1 mmol) were added to
a reaction tube. Ethanol (1.0 mL)
was added, and the resulting reac-
tion mixture was stirred at RT for
2–48 h. The solvent was removed
under reduced pressure and resi-
due was chromatographed on
silica gel (elution with petroleum
ether/EtOAc=6:1–4:1) to provide
the desired product or filtrated to
get the product.
Ethyl 2,3-bis(1’-benzyl-spiro-3’-in-
dolino)-hexahydro-1H-pyrroli-
zine-1-carboxylate (3a): White
solid (57 mg 96%): mp: 151–
1528C; 1H NMR (400 MHz, CDCl3,
TMS): d=7.69 (d, J=8.0 Hz, 1H),
7.58 (d, J=8.0 Hz, 1H), 7.14–6.87
(m, 10H), 6.69 (d, J=6.8 Hz, 2H),
6.50 (d, J=6.8 Hz, 2H), 6.43 (t, J=
8.0 Hz, 2H), 5.28–5.23 (m, 1H), 5.06
(d, J=16.0 Hz, 1H), 4.91 (d, J=
16.0 Hz, 1H), 4.48 (d, J=16.0 Hz,
1H), 4.21 (d, J=16.0 Hz, 1H), 3.88
(d, J=10.0 Hz, 1H), 3.79–3.71 (m,
1H), 3.68–3.55 (m, 2H), 2.92 (t, J=
8.4 Hz, 1H), 2.47–2.40 (m, 1H),
2.16–2.00 (m, 2H), 1.94–1.88 (m,
1H), 0.55 (t, J=8.0 Hz, 3H);
13C NMR (100 MHz, CDCl3): d=
177.2, 175.2, 169.9, 143.5, 142.9,
135.2, 129.6, 128.7, 128.6, 128.5,
Scheme 3. Substrate scope of three-component 1,3-dipolar cycloaddition reaction of 1, l-proline and 8.
stereochemistry of bispiro compound 11 has been determined
by single-crystal X-ray analysis and its ORTEP drawing is indi-
cated in Figure 3.
127.7, 127.1, 127.0, 126.6, 126.4, 126.3, 122.5, 122.1, 109.0, 108.5,
77.9, 67.1, 66.6, 60.3, 57.9, 48.1, 43.8, 43.4, 29.7, 26.0, 13.4; IR (neat)
n˜ =3064, 1729, 1703, 1607, 1487, 1361, 1178, 1113, 1015, 761,
ꢀ 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemistryOpen 2014, 3, 93 – 98 96

www.chemistryopen.org
Acknowledgement
We are grateful for financial sup-
port from Shanghai Municipal
Committee of Science and Tech-
nology, China (11JC1402600), the
National Basic Research Program
of China ((973)-2010CB833302),
and the National Natural Science
Foundation of China (20472096,
21372241, 21361140350, 20672127,
21102166, 21121062, 21302203
and 20732008).
Keywords: azomethine ylides ·
bispirooxindoles · cycloaddition ·
Scheme 4. [3+2] Annulation of A) olefin 10 and B) olefin 12.
stereochemistry
olefins
·
substituted
[1] a) G. M. Nicholas, L. L. Eckman, G. L. Newton, Bioorg. Med. Chem. 2003,
11, 601; b) K. Suenaga, K. Araki, T. Sengoku, Org. Lett. 2001, 3, 527;
c) W. G. Beyersbergen van Henegouwen, R. M. Fieseler, F. P. J. T. Rutjes,
H. Hiemstra, J. Org. Chem. 2000, 65, 8317; d) P. Ciminiello, C. Dell’Aversa-
no, E. Fattorusso, S. Magno, M Pansini, J. Nat. Prod. 1999, 62, 590;
e) B. C. M. Potts, D. J. Faulkner, J. A. Chan, G. C. Simolike, P. Offen, M. E.
Hemling, T. A. Francis, J. Am. Chem. Soc. 1991, 113, 6321.
[2] For selected reviews, see: a) B. M. Trost, M. K. Brennan, Synthesis 2009,
3003; b) C. V. Galliford, K. A. Scheidt, Angew. Chem. 2007, 119, 8902;
Angew. Chem. Int. Ed. 2007, 46, 8748; c) C. Marti, E. M. Carreira, Eur. J.
Org. Chem. 2003, 2209; d) D. B. Ramachary, N. S. Chowdari, C. F. Barba-
s III, Angew. Chem. 2003, 115, 4365; Angew. Chem. Int. Ed. 2003, 42,
4233; e) D. Enders, C. Grondal, M. R. M. Huttl, Angew. Chem. 2007, 119,
1590; Angew. Chem. Int. Ed. 2007, 46, 1570; f) K. C. Nicolaou, J. S. Chen,
Chem. Soc. Rev. 2009, 38, 2993.
[3] For selected examples of recent years, see: a) G. Bencivenni, L.-Y. Wu, A.
Mazzanti, B. Giannichi, F. Pesciaioli, M.-P. Song, G. Bartoli, P. Melchiorre,
Angew. Chem. 2009, 121, 7336; Angew. Chem. Int. Ed. 2009, 48, 7200;
b) X.-H. Chen, Q. Wei, S.-W. Luo, H. Xiao, L.-Z. Gong, J. Am. Chem. Soc.
2009, 131, 13819; c) J. Dugal-Tessier, E. A. O’Bryan, T. B. H. Schroeder,
D. T. Cohen, K. A. Scheidt, Angew. Chem. 2012, 124, 5047; Angew. Chem.
Int. Ed. 2012, 51, 4963; d) K. Jiang, Z.-J. Jia, S. Chen, L. Wu, Y.-C. Chen,
Chem. Eur. J. 2010, 16, 2852; e) C. Lu, Q. Xiao, P. E. Floreancig, Org. Lett.
2010, 12, 5112; f) L. Shen, P. Shao, S. Ye, Adv. Synth. Catal. 2011, 353,
1943; g) S. Duce, F. Pesciaioli, L. Gramigna, L. Bernardi, A. Mazzanti, A.
Ricc, G. Bartoli, G. Bencivenni, Adv. Synth. Catal. 2011, 353, 860; h) F.
Zhong, X. Han, Y. Wang, Y. Lu, Angew. Chem. 2011, 123, 7983; Angew.
Chem. Int. Ed. 2011, 50, 7837; i) B. Tan, R. N. Candeias, C. F. Barbas III, J.
Am. Chem. Soc. 2011, 133, 4672; j) S. Kato, T. Yoshino, M. Shibasaki, M.
Kanai, S. Matsunaga, Angew. Chem. 2012, 124, 7113; Angew. Chem. Int.
Ed. 2012, 51, 7007; k) Z. Jia, H. Jiang, J. Li, B. Gschwend, Q. Li, X. Yin, J.
Grouleff, K. A. Jørgensen, J. Am. Chem. Soc. 2011, 133, 5053.
Figure 3. The X-ray crystal structure of 11.
694 cmÀ1; MS (ESI): m/z (%): 598.4 (100) [M+H]+; HRMS: m/z [M+
H]+ calcd for C38H36N3O4: 598.2708, found: 598.2700.
[4] a) M. A. Ali, R. Ismail, T. S. Choon, Y. K. Yoon, A. C. Wei, S. Pandian, R. S.
Kumar, H. Osman, E. Manogaran, Bioorg. Med. Chem. Lett. 2010, 20,
7064; b) A. S. Girgis, Eur. J. Med. Chem. 2009, 44, 91; c) R. R. Kumar, S.
Perumal, P. Senthikumar, P. Yogeeswari, D. Sriram, J. Med. Chem. 2008,
51, 5731–5735; d) T. Jiang, K. L. Kuhen, K. Wolff, H. Yin, K. Bieza, J. Cald-
well, B. Bursulaya, T. Y.-H. Wu, Y. He, Bioorg. Med. Chem. Lett. 2006, 16,
2105–2108; e) M. Rottmann, Science 2010, 329, 1175; f) G. Periyasami,
R. Raghunathan, G. Surendiran, N. Mathivanan, Bioorg. Med. Chem. Lett.
2008, 18, 2342; g) R. Murugan, S. Anbazhagan, S. S. Narayanan, Eur. J.
Med. Chem. 2009, 44, 3272; h) R. Ranjith Kumar, S. Perumal, P. Senthilku-
mar, P. Yogeeswari, D. Sriram, Eur. J. Med. Chem. 2009, 44, 3821.
Spectroscopic data of the compounds shown in Tables 1–3 and
Scheme 1–3, the detailed descriptions of experimental procedures
and the crystal structures of 3a, 5g, 8c and 11 are given in the
Supporting Information. CCDC-821930 (3a), CCDC-824511 (5g),
CCDC-826476 (8c) and CCDC-863229 (11) contain the supplemen-
tary crystallographic data for this paper. These data can be ob-
tained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
[5] For selected examples of recent years, see: a) Y. Cao, X. Jiang, L. Liu, F.
Shen, F. Zhang, R. Wang, Angew. Chem. 2011, 123, 9290; Angew. Chem.
Int. Ed. 2011, 50, 9124; b) X. Jiang, Y. Cao, Y. Wang, L. Liu, F. Shen, R.
ꢀ 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemistryOpen 2014, 3, 93 – 98 97

www.chemistryopen.org
Wang, J. Am. Chem. Soc. 2010, 132, 15328; c) J. Wang, E. A. Crane, K. A.
Scheidt, Org. Lett. 2011, 13, 3086; d) S. M. Hande, M. Nakajima, H. Kami-
saki, C. Tsukano, Y. Takemoto, Org. Lett. 2011, 13, 1828; e) J. J. Badillo,
G. E. Arevalo, J. C. Fettinger, A. K. Franz, Org. Lett. 2011, 13, 418; f) T.
Chen, X.-P. Xu, S. Ji, J. Comb. Chem. 2010, 12, 659; g) Y. Li, H. Chen, C.
Shi, D. Shi, S. Ji, J. Comb. Chem. 2010, 12, 231; h) H. Chen, D. Shi, J.
Comb. Chem. 2010, 12, 571; i) R. Shintani, S.-y. Hayashi, M. Murakami, M.
Takeda, T. Hayashi, Org. Lett. 2009, 11, 3754; j) Y.-L. Liu, X. Wang, Y.-L.
Zhao, F. Zhu, X.-P. Zeng, L. Cheng, C.-H. Wang, X.-L. Zhao, J. Zhou,
Angew. Chem. 2013, 125, 13980; Angew. Chem. Int. Ed. 2013, 52, 13735.
[6] For reviews, see: a) G. S. Singh, Z. Y. Desta, Chem. Rev. 2012, 112, 6104;
b) R. Dalpozzo, G. Bartoli, G. Bencivenni, Chem. Soc. Rev. 2012, 41,
7247–7290; c) F. Zhou, Y.-L. Liu, J. Zhou, Adv. Synth. Catal. 2010, 352,
1381; d) Y. Liu, H. Wang, J. Wan, Asian J. Org. Chem. 2013, 2, 374.
[7] R. Grigg, M. F. Aly, V. Sridharan, S. Thianpatanagul, J. Chem. Soc. Chem.
Commun. 1984, 182.
Org. Lett. 2007, 9, 4095–4098; c) J. Azizian, A. Asadi, K. Jadidi, Synth.
Commun. 2001, 31, 2727–2733; d) V. Nair, K. C. Sheela, N. P. Rath, Chem.
Lett. 2000, 980; e) M. Ghandi, A. Taheri, A. Abbasi, Tetrahedron 2010, 66,
6744; f) N. V. Lakshmi, P. Thirumurugan, P. T. Perumal, Tetrahedron Lett.
2010, 51, 1064; g) J. N. S. Rao, R. Raghunathan, Tetrahedron Lett. 2012,
53, 854; h) A. R. S. Babu, R. Raghunathan, Tetrahedron Lett. 2008, 49,
4618; i) A. R. Suresh Babu, R. Raghunathan, Tetrahedron Lett. 2008, 49,
4487; j) A. R. Suresh Babu, R. Raghunathan, Tetrahedron Lett. 2007, 48,
305; k) J. Jayashankaran, R. D. R. S. Maniyan, R. Raghunathan, Tetrahe-
dron Lett. 2004, 45, 7303; l) A. Thangamani, Eur. J. Med. Chem. 2010, 45,
6120; m) R. Suresh Kumar, S. Perumal, Tetrahedron Lett. 2007, 48, 7164;
n) R. Suresh Kumar, S. M. Rajesh, S. Perumal, D. Banerjee, P. Yogeeswari,
D. Sriram, Eur. J. Med. Chem. 2010, 45, 411; o) H. Liu, G. Dou, D. Shi, J.
Comb. Chem. 2010, 12, 292; p) X.-F. Hu, Y.-Q. Feng, Synth. Commun.
2005, 35, 1747; q) N. V. Lakshmi, P. Thirumurugan, C. Jayakumar, P. T. Pe-
rumal, Synlett 2010, 6, 955.
[8] O. Tsuge, S. Kanemasa, M. Ohe, S. Takenaka, Bull. Chem. Soc. Jpn. 1987,
60, 4079.
[11] a) A. Rehn, J. Bergman, B. Stensland, Eur. J. Org. Chem. 2004, 413–418;
b) B. Tan, N. R. Candeias, C. F. Barbas, III, Nat. Chem. 2011, 3, 473; c) J.
Liu, H. Sun, X. Liu, L. Ouyang, T. Kang, Y. Xie, X. Wang, Tetrahedron Lett.
2012, 53, 2336–2340; d) Y.-Y. Han, W.-B. Chen, W.-Y. Han, Z.-J. Wu, X.-M.
Zhang, W.-C. Yuan, Org. Lett. 2012, 14, 490; e) Y.-M. Cao, F.-F. Shen, F.-T.
Zhang, R. Wang, Chem. Eur. J. 2013, 19, 1184; f) J. Li, Y. Liu, C. Li, X. Jia,
Chem. Eur. J. 2011, 17, 7409; g) B. Zhang, P. Feng, L.-H. Sun, Y. Cui, S. Ye,
N. Jiao, Chem. Eur. J. 2012, 18, 9198.
[9] a) A. Franke, Justus. Liebigs Ann. Chem. 1978, 717; b) A. Casaschi, G. De-
simoni, G. Faita, A. G. Invernizzi, P. Grꢁnanger, Heterocycles 1994, 37,
1673; c) M. F. Aly, G. M. El-Nagger, T. I. El-Emary, R. Grigg, S. A. M. Met-
wally, S. Sivagnanam, Tetrahedron 1994, 50, 895; d) T. Coulter, R. Grigg,
J. F. Malone, V. Sridharan, Tetrahedron Lett. 1991, 32, 5417; e) H. Ardill, R.
Grigg, V. Sridharan, S. Surendrakumar, S. Thianpatanagul, S. Kanajun, J.
Chem. Soc. Chem. Commun. 1986, 602; f) H. Ardill, M. J. R. Dorrity, R.
Grigg, M. S. Leon-Ling, J. F. Malone, V. Sridharan, S. Thianpatanagul, Tet-
rahedron 1990, 46, 6433.
[10] a) M. Bakthadoss, N. Sivakumar, A. Devaraj, D. S. Sharada, Synthesis
2011, 2136–2146; b) P. Shanmugam, B. Viswambharan, S. Madhavan,
Received: March 13, 2014
ꢀ 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemistryOpen 2014, 3, 93 – 98 98