Gold(i)-catalyzed highly stereoselective synthesis of polycyclic indolines: The construction of four contiguous stereocenters

Article abstract of DOI:10.1039/c5cc08381h

A convenient and efficient synthetic method has been developed to construct highly functionalized polycyclic indoline skeletons with four contiguous stereocenters, which are of great importance in biological and pharmaceutical chemistry. The selective formation of either the oxabridged-ring or ring-opening polycyclic indoline derivatives can be controlled by using different gold catalytic systems. A variety of polycyclic indoline derivatives were obtained in moderate to good yields under mild conditions with moderate to excellent enantioselectivity.

Full text of DOI:10.1039/c5cc08381h

View Article Online
View Journal
ChemComm
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: M. Shi, J. Yang, Y.
Wei, X. Tang and P. Li, Chem. Commun., 2015, DOI: 10.1039/C5CC08381H.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the Ethical guidelines still
apply. In no event shall the Royal Society of Chemistry be held
responsible for any errors or omissions in this Accepted Manuscript
or any consequences arising from the use of any information it
contains.
www.rsc.org/chemcomm

Please do not adjust margins
ChemComm
Page 1 of 5
View Article Online
DOI: 10.1039/C5CC08381H
Journal Name
COMMUNICATION
Gold(I)-Catalyzed Highly Stereoselective Synthesis of Polycyclic
Indolines: Construction of Four Contiguous Stereocenters
Received 00th January 20xx,
Accepted 00th January 20xx
Jin-Ming Yang,a Peng-Hua Li,b Yin Wei,a Xiang-Ying Tang,*a and Min Shi*ab
DOI: 10.1039/x0xx00000x
www.rsc.org/
A convenient and efficient synthetic method has been developed Zhang,[7] Echavarren[8] and others[9] have intensively
to construct highly functionalized polycyclic indoline skeletons investigated the diverse transformations of these substrates.
with four contiguous stereocenters, which are of great importance In 2005, the pioneering work on the intramolecular cyclization
in biological and pharmaceutical chemistry. Selective formation of of indolyl propargylic esters catalyzed by AuI species to afford
either the oxabridged-ring or ring-opening polycyclic indoline polycyclic indolines
B through [2+2] cycloaddition was
derivatives can be controlled by using different gold catalytic reported by Zhang[7a] and co-workers. Afterwards, by varying
systems. A variety of polycyclic indoline derivatives were obtained the metal catalyst into PtII, they developed a rapid access to
in moderate to good yields under mild conditions along with tetracyclic 2,3-indoline-fused cyclopentenes C from the same
moderate to excellent enantioselectivities.
substrates[7b] (Scheme 1a). Very recently, Toste[9b] et al.
reported a highly enantioselective dearomative Rautenstrauch
The indoline moiety is a privileged heterocyclic substructure
in many biologically active natural products and
pharmaceutically valuable compounds.[1] Among these
polyheterocycles, the structurally diverse and biologically
interesting azepino[a]indoline skeletons, which feature a fused
seven-membered ring through the N1−C2 connecꢀon, are of
great importance because of their well-represented and wide
distribution in pharmaceutical chemistry. For instance,
Scheme 1. Previous and our work on the synthesis of polycyclic
indolines.
O
a) Zhang's work:
path a: [2+2]
MXn: [Au(PPh3)Cl]/AgSbF6
O
R3
2
R3
O
MXn R
DCM, RT
N
R1
H
O
B
R2
R3
MXn
O
O
azepino[a]indoline-based agonists were found to be
a
N
1,3-Shift
O
potential drug candidate for the treatment of anxiety[2a] as
well as promising inhibitors against human protein kinases.[2b]
To date, most documents have been concentrated on the
synthesis of 2,3-fused indolines.[3] To the best of our
knowledge, however, 1,2-fused indolines, especially
azepino[a]indolines, have been prepared in a few cases.[4] Thus,
the development of an efficient synthetic method to build
such polyheterocyclic skeletons is in need.
R1
path b: [3+2]
O
R2
N
R1
R3
MXn: PtCl2, CO (1 atm)
Toluene, 80 o
C
A
N
R1
H
R2
C
b) This work:
O
R1
O
H
[Au(tBuXPhos)][OTf]
H2O
[Au]
DCE, RT
H
N
O
X
[Au]
O
X
R1
2
R2
[Au]
1,2-Shift
X
O
O
R1
7
N
OH
H
N1
R1
6
R2
Gold catalysis, which is currently
a
hot topic in
O
5
R2
O
2
[(IPr)Au(CH3CN)][SbF6]
DCE, H2O, RT
homogeneous catalysis, can be well understood with the
concept of carbophilic π-acids, which are widely employed in
the activation of C−C multiple bonds.[5] In particular, gold-
catalyzed cyclization of indole derivatives have attracted much
attention owing to the efficient synthesis of polyheterocyclic
skeletons.[6-9] Thus far, the research groups of Bandini,[6]
4
3
D
H
N
X
1: X = NTs, CH2, O
R2
3
rearrangement catalyzed by cationic gold(I), providing a
straightforward method to prepare enantioenriched
cyclopenta[b]indolines. As a part of our ongoing interest in
indole derivatives and propargylic esters,[10] we have already
reported several interesting transformations from indole
substrates as well as propargylic esters.[11] Based on these
findings, we envisaged that indoles bearing propargylic esters
might undergo very interesting transformations. To our great
a.State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic
Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032
China. E-mail: siocxiangying@mail.sioc.ac.cn; mshi@mail.sioc.ac.cn
b.Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China
University of Science and Technology, Meilong Road No. 130, Shanghai, 200237
(China).
† Electronic Supplementary Information (ESI) available: Experimental procedures,
characterization data of new compounds, and CCDC 1058692 and 1035121. See
DOI: 10.1039/b000000x
delight, upon treatment of substrates
polycyclic indolines and could be obtained selectively
through a gold vinyl carbene intermediate . Notably, the
1 with a gold catalyst,
2
3
D
oxabridged-ring products
2
would be transformed into ring-
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 2 of 5
View Article Online
DOI: 10.1039/C5CC08381H
COMMUNICATION
Journal Name
opening products
catalyst (Scheme 1b).
3
in the presence of water and the gold suitable for this cyclization. The structure of 2r has been
unequivocally confirmed by X-ray diffraction.[12]
Initially, we started our investigation by using model
substrate 1a, 5 mol% of [Au(tBuXPhos)][OTf] in anhydrous DCE
(1,2-dichloroethane) at room temperature (RT), giving the
polycyclic oxabridged-ring product 2a in 95% yield after 2 h
(Table 1, entry 1). However, when 1a was treated with
[Au(Me4tBuXPhos)(CH3CN)][SbF6], no reaction occurred,
presumably due to the steric effect of the phosphine ligand
(Table 1, entry 2) (for their structures, see Figure S1 in the
Supporting Information). Using [(IPr)Au(CH3CN)][SbF6] (IPr =
Table 2. Substrate scope of the reaction in the presence of
[Au(tBuXPhos)][OTf].
1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene)
as
the
catalyst, we obtained a different polycyclic ring-opening
product 3a in 70% yield instead of the desired product 2a
perhaps due to the ambient water (Table 1, entry 2). The
structure of 3a has been unequivocally confirmed by X-ray
diffraction.[12] The use of cationic gold(I) complex
[Au(nBuPAd2)(CH3CN)][SbF6] led to an increase of the yield of
3a to 89% (Table 1, entry 4). With an electron-deficient
phosphite P(OAr)3 as the ligand, an inferior result was
obtained (Table 1, entry 5). The reaction efficiency was
significantly improved by the addition of 1.0 equivalent of
water (Table 1, entries 3 and 6). 5 mol% of [Ph3PAuCl]/AgNTf2
did not give a better result (Table 1, entry 7). Furthermore,
decreasing the employed amount of catalyst did not have
significant impact on the reaction outcome (Table 1, entry 8).
Thus, finally, we established the optimal reaction conditions: 5
mol% of [Au(tBuXPhos)][OTf] in anhydrous DCE at room
temperature for the synthesis of compound 2a or 2.5 mol% of
[(IPr)Au(CH3CN)][SbF6] in wet DCE (anhydrous DCE with the
addition of 1.0 equiv of H2O) at room temperature for the
synthesis of compound 3a
.
Next, further examinations were performed to extend the scope
of this cyclization in the presence of [(IPr)Au(CH3CN)][SbF6] (Table
3). As can be seen from Table 3, substrates 1a-g bearing o-, m-
methylbenzenesulfonyl, benzenesulfonyl mesitylenesulfonyl (Mes),
2,4,6-triisopropylbenzenesulfonyl and p-bromobenzenesulfonyl (Bs)
groups all gave the desired products 3a-g in 71-89% yields,
indicating that the electronic properties and steric effects of the
sulfonyl group did not have significant impact on the reaction
Table 1. Optimization of the Reaction Conditions.
outcome. Meanwhile,
electron-donating (1h-k)
a
variety of substrates bearing either
or electron-withdrawing (1l-o)
substituents on the indole core worked smoothly, furnishing the
corresponding polycyclic adducts 3h-o in 64-85% yields. Moreover,
the oxygen- or carbon-tethered substrates 1p and 1q were also
suitable for this cyclization, providing the desired products in
reasonable yields. Furthermore, reactions of starting materials with
an acetyl (MeC(O)-, 1r) or a pendant benzoyl (Bz, 1s) group were
found to be well-tolerated under the standard conditions,
furnishing the corresponding products 3r-s in 94% and 70% yields,
respectively. Moreover, we also tested a substrate bearing 4-Me on
the indole core (1u), however the reaction became very complex
under the optimized conditions. This might be due to the steric
hindrance of the methyl group with the tert-butyl group, and
therefore, the formal [3+2] cycloaddition was blocked out. Using
[Au(nBuPAd2)(CH3CN)][SbF6] instead of [(IPr)Au(CH3CN)][SbF6] as
the catalyst afforded a new product 4u through a 7-exo-dig
cyclization process (Scheme 2).[8] Substrate 1q also gave 4q in 71%
yield with this gold catalyst through the same reaction pathway
(Scheme 2). When the migrating group was carbobenzyloxy (Cbz, X
= NTs, 1t), no reaction occurred under the standard conditions.
With the optimized conditions in hand, we turned our attention
to determine the scope and limitations of the reaction in the
presence of [Au(tBuXPhos)][OTf]. As summarized in Table 2, all of
the reactions proceeded smoothly to afford the corresponding
products 2a-d in good to excellent yields upon isolation (80-96%)
when R1 sulfonyl group was p-, o-, m-methylbenzenesulfonyl or
benzenesulfonyl. Next, the scope of this transformation with
respect to the indole moiety was examined. Substrates bearing
either electron-donating (5-Me, 6-Me, 7-Me, 5-OMe) or electron-
withdrawing (6-F, 5-Br, 6-Br, 6-Cl) groups on the indole core all
afforded the corresponding products 2h-o in moderate to good
yields. Furthermore, the substrate 1r bearing an acetyl (MeC(O)-)
moiety instead of pivaloyl (Piv, 1a) as the migrating group was also
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 3 of 5
View Article Online
DOI: 10.1039/C5CC08381H
Journal Name
COMMUNICATION
moieties were well tolerated, affording the desired products in 46-
88% yields with 62-82% ee values, regardless of whether they were
electron-donating or electron-withdrawing groups (Table 4, entries
5-11) (for more information, see Table S2 in the Supporting
Information).
Table 3. Substrate scope of the reaction in the presence of
[(IPr)Au(CH3CN)][SbF6].
Table 4. Substrate scope of enantioselective Au(I)-catalyzed
cyclization of 1.
A plausible mechanism for this reaction is outlined in
Scheme 3 on the basis of previous literature.[10g,l] Gold(I)
activation of the triple bond in
gold carbene intermediate through a 1,2-acyloxy migration.
A nucleophilic attack of the carbonyl group to the gold carbene
results in the formation of the 1,3-dipolar intermediate
which undergoes a [3+2] cycloaddition with C2−C3 of the
indole moiety to afford the vinyl ketal product and
regenerate the gold catalyst. Finally, hydrolysis of by water
provides the ring-opening product . Notably, 2a was found to
1 promotes the formation of
H
J
,
2
2
Scheme 2. Different reaction pathway.
3
be stable overnight upon exposure to 3.0 equivalent of water
in DCE, but was easily converted into 3a in 86% yield when
treated again with 2.5 mol% of [(IPr)Au(CH3CN)][SbF6] (see
Scheme S6 in the Supporting Information), thus suggesting the
critical role of the gold catalyst during the ring-opening event.
Scheme 3. A plausible reaction mechanism.
Driven by the demand to construct highly enantioenriched
polycyclic indolines through asymmetric gold catalysis,[11a,13] which
still remains a challenging topic because of the linear geometry of
the gold(I) complexes, we thus attempted asymmetric synthesis of
these polycyclic indolines. The results of our examination of the
enantioselective cyclization of 1a are shown in Table S1 (see
Supporting Information for the details). Among the commonly used
chiral phosphine ligands, the use of Feringa phosphoramidite L5[14]
resulted in the best enantioselectivity. Optimization of the reaction
conditions revealed that carrying out the reaction in DCE at 0 oC
with AgNTf2 as the co-catalyst was the best condition for this
asymmetric reaction. Next, we performed the reaction under the
optimized conditions to synthesize enantioenriched polycyclic
indolines 3 and the results are summarized in Table 4. Substrates
In conclusion, we have developed a highly efficient and accessible
gold(I)-catalyzed intramolecular cyclization of indolyl propargylic
esters. A variety of polycyclic indolines bearing four contiguous
stereocenters are obtained in moderate to excellent yields under
mild conditions in high stereoselectivities with wide azepine ring
flexibility (N, C, O). The reaction mechanism is proposed on the
basis of control experiments and isolated key intermediates.
1c-f
bearing
m-methylbenzenesulfonyl,
benzenesulfonyl,
mesitylenesulfonyl (Mes) and 2,4,6-triisopropylbenzenesulfonyl
groups gave the desired products 3c-f in moderate yields along with
good to excellent ee values (Table 4, entries 1-4). Meanwhile, a
range of substituents at 5-, 6-, and 7-positions of the indole
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 4 of 5
View Article Online
DOI: 10.1039/C5CC08381H
COMMUNICATION
Journal Name
10 For recent reviews of propargylic esters, see: a) S. Wang, G.
Zhang, L. Zhang, Synlett 2010, 5, 692; b) R. K. Shiroodi, V.
Gevorgyan, Chem. Soc. Rev. 2013, 42, 4991. For selected
work on propargylic esters, see: c) H. Zheng, J. Zheng, B. Yu,
Q. Chen, X. Wang, Y. He, Z. Yang, X. She, J. Am. Chem. Soc.
2010, 132, 1788; d) D. Leboeuf, A. Simonneau, C. Aubert, M.
Malacria, V. Gandon, L. Fensterbank, Angew. Chem., Int. Ed.
2011, 50, 6868; e) S. Cai, Z. Liu, W. Zhang, X. Zhao, D. Z.
Wang, Angew. Chem., Int. Ed. 2011, 50, 11133; f) Y. Yu, W.
Yang, F. Rominger, A. S. K. Hashmi, Angew. Chem., Int. Ed.
2013, 52, 7586; g) W. Rao, M. J. Koh, D. Li, H. Hirao, P. W. H.
Chan, J. Am. Chem. Soc. 2013, 135, 7926; h) C. Zhao, X. Xie,
Further applications of this chemistry and more detailed
mechanistic investigations are underway in our laboratory.
We are grateful for the financial support from the National
Basic Research Program of China (973)-2015CB856603, and
the National Natural Science Foundation of China (20472096,
21372241, 21361140350, 20672127, 21421091, 21372250,
21121062, 21302203, 20732008 and 21572052).
Notes and references
S. Duan, H. Li, R. Fang, X. She, Angew. Chem., Int. Ed. 2014
,
1
a) D. Zhang, H. Song, Y. Qin, Acc. Chem. Res. 2011, 44, 447; b)
L. Chang, J. D. Podoll, W. Wang, S. Walls, C. P. O'Rourke, X.
Wang, J. Med. Chem. 2014, 57, 3803; c) P. Michael Barbour,
J. D. Podoll, L. J. Marholz, X. Wang, Bioorg. Med. Chem. Lett.
2014, 24, 5602; d) W. Zi, Z. Zuo, D. Ma, Acc. Chem. Res.
2015, 48, 702.
53, 10789; i) W. Rao, D. Susanti, B. J. Ayers, P. W. H. Chan, J.
Am. Chem. Soc. 2015, 137, 6350.
11 For our previous work on indole chemistry, see: a) L. Huang,
H.-B. Yang, D.-H. Zhang, Z. Zhang, X.-Y. Tang, Q. Xu, M. Shi,
Angew. Chem., Int. Ed. 2013, 52, 6767; b) D.-H. Zhang, X.-Y.
Tang, Y. Wei, M. Shi, Chem. Eur. J. 2013, 19, 13668; c) Z.
Zhang, X. Tang, Q. Xu, M. Shi, Chem. Eur. J. 2013, 19, 10625;
d) J.-M. Yang, C.-Z. Zhu, X.-Y. Tang, M. Shi, Angew. Chem.,
2
a) M. D. Ennis, R. L. Hoffman, N. B. Ghazal, R. M. Olson, C. S.
Knauer, C. L. Chio, D. K. Hyslop, J. E. Campbell, L. W.
Fitzgerald, N. F. Nichols, K. A. Svensson, R. B. McCall, C. L.
Haber, M. L. Kagey, D. M. Dinh, Bioorg. Med. Chem. Lett.
2003, 13, 2369; b) V. N. Danilenko, A. Y. Simonov, S. A.
Lakatosh, M. H. G. Kubbutat, F. Totzke, C. Schächtele, S. M.
Elizarov, O. B. Bekker, S. S. Printsevskaya, Y. N. Luzikov, M. I.
Reznikova, A. A. Shtil, M. N. Preobrazhenskaya, J. Med.
Chem. 2008, 51, 7731.
Int. Ed. 2014, 53, 5142. For our previous work on
propargylic esters, see: e) Z. Zhang, M. Shi, Eur. J. Org.
Chem. 2011, 2610; f) D.-H. Zhang, L.-F. Yao, Y. Wei, M. Shi,
Angew. Chem., Int. Ed. 2011, 50, 2583; g) J.-M. Yang, Z.
Zhang, Y. Wei, M. Shi, Tetrahedron Lett. 2012, 53, 6173; h)
Z. Zhang, M. Shi, Chem. Eur. J. 2012, 18, 3654; i) J.-M. Yang,
X.-Y. Tang, M. Shi, Chem. Eur. J. 2015, 21, 4534.
3
a) A. M. Hyde, S. L. Buchwald, Angew. Chem., Int. Ed. 2008,
12 The molecular structures of products 2r and 3a have been
determined by means of X-ray crystallographic studies.
Their ORTEP drawings and the corresponding CIF data have
been presented in the Supporting Information.
47, 177; b) Y. Liu, W. Xu, X. Wang, Org. Lett. 2010, 12, 1448;
c) Q. Cai, C. Zheng, J.-W. Zhang, S.-L. You, Angew. Chem.,
Int. Ed. 2011, 50, 8665; d) N. Simpkins, I. Pavlakos, L. Male,
Chem. Commun. 2012, 48, 1958; e) X. Zhang, L. Han, S.-L.
You, Chem. Sci. 2014, 5, 1059; f) G. Mei, H. Yuan, Y. Gu, W.
Chen, L. W. Chung, C.-C. Li, Angew. Chem., Int. Ed. 2014, 53,
1105; g) X. Zhao, X. Liu, H. Mei, J. Guo, L. Lin, X. Feng,
Angew. Chem., Int. Ed. 2015, 54, 4032; h) Y. Tokimizu, S.
Oishi, N. Fujii, H. Ohno, Angew. Chem., Int. Ed. 2015, 54,
7862.
13 For selected examples on chiral AuI catalysis, see: a) H.
Teller, S. Flügge, R. Goddard, A. Fürstner, Angew. Chem.,
Int. Ed. 2010, 49, 1949; b) A. Z. Gonzalez, D. Benitez, E.
Tkatchouk, W. A. Goddard, III, F. D. Toste, J. Am. Chem. Soc.
2011, 133, 5500; c) S. A. Gawade, S. Bhunia, R.-S. Liu,
Angew. Chem., Int. Ed. 2012, 51, 7835; d) S. Suárez-Pantiga,
C. Hernández-Díaz, E. Rubio, J. M. González, Angew. Chem.,
Int. Ed. 2012, 51, 11552; e) H. Teller, M. Corbet, L. Mantilli,
G. Gopakumar, R. Goddard, W. Thiel, A. Fürstner, J. Am.
Chem. Soc. 2012, 134, 15331; f) W. Zi, F. D. Toste, J. Am.
Chem. Soc. 2013, 135, 12600; g) Z.-M. Zhang, P. Chen, W. Li,
Y. Niu, X.-L. Zhao, J. Zhang, Angew. Chem., Int. Ed. 2014, 53,
4350; h) D. Qian, H. Hu, F. Liu, B. Tang, W. Ye, Y. Wang, J.
Zhang, Angew. Chem., Int. Ed. 2014, 53, 13751; i) K. Ji, Z.
Zheng, Z. Wang, L. Zhang, Angew. Chem., Int. Ed. 2015, 54,
1245. Also see refs. [6c,9b,11a]. For reviews of asymmetric
gold catalysis, see: j) N. Bongers, N. Krause, Angew. Chem.,
Int. Ed. 2008, 47, 2178; k) R. A. Widenhoefer, Chem. Eur. J.
2008, 14, 5382; m) A. Pradal, P. Y. Toullec, V. Michelet,
Synthesis 2011, 1501. Also see refs. [5c,d,j].
4
5
S. J. Mahoney, E. Fillion, Chem. Eur. J. 2012, 18, 68. Also see
ref. [2a].
For selected reviews of gold catalysis, see: a) S. Sengupta, X.
Shi, ChemCatChem 2010, 2, 609; b) M. Bandini, Chem. Soc.
Rev. 2011, 40, 1358; c) B.-L. Lu, L. Dai, M. Shi, Chem. Soc.
Rev. 2012, 41, 3318; d) D.-H. Zhang, X.-Y. Tang, M. Shi, Acc.
Chem. Res. 2013, 47, 913; e) A. S. K. Hashmi, Acc. Chem.
Res. 2014, 47, 864; f) L. Zhang, Acc. Chem. Res. 2014, 47,
877; g) Y.-M. Wang, A. D. Lackner, F. D. Toste, Acc. Chem.
Res. 2014, 47, 889; h) C. Obradors; A. M. Echavarren, Acc.
Chem. Res. 2014, 47, 902; i) L. Fensterbank, M. Malacria,
Acc. Chem. Res. 2014, 47, 953; j) H.-S. Yeom, S. Shin, Acc.
Chem. Res. 2014, 47, 966; k) R. Dorel, A. M. Echavarren,
Chem. Rev. 2015, 115, 9028.
14 For a review, see: J. F. Teichert, B. Feringa, Angew. Chem.,
Int. Ed. 2010, 49, 2486.
6
a) M. Bandini, A. Eichholzer, Angew. Chem., Int. Ed. 2009, 48,
9533; b) M. Bandini, A. Eichholzer, Angew. Chem., Int. Ed.
2009, 48, 9608; c) M. Bandini, A. Bottoni, M. Chiarucci, G.
Cera, G. P. Miscione, J. Am. Chem. Soc. 2012, 134, 20690; d)
M. Jia, M. Monari, Q.-Q. Yang, M. Bandini, Chem. Commun.
2015, 51, 2320.
7
8
a) L. Zhang, J. Am. Chem. Soc. 2005, 127, 16804; b) G. Zhang,
V. J. Catalano, L. Zhang, J. Am. Chem. Soc. 2007, 129, 11358.
a) C. Ferrer, A. M. Echavarren, Angew. Chem., Int. Ed. 2006
,
45, 1105; b) C. Ferrer, C. H. M. Amijs, A. M. Echavarren,
Chem. Eur. J. 2007, 13, 1358.
9
a) S. G. Modha, A. Kumar, D. D. Vachhani, J. Jacobs, S. K.
Sharma, V. S. Parmar, L. V. Meervelt, E. V. V. der Eycken,
Angew. Chem., Int. Ed. 2012, 51, 9572; b) W. Zi, H. Wu, F. D.
Toste, J. Am. Chem. Soc. 2015, 137, 3225.
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 5 of 5
View Article Online
DOI: 10.1039/C5CC08381H
Journal Name
COMMUNICATION
Gold(I)-Catalyzed Highly Stereoselective Synthesis of Polycyclic
Indolines: Construction of Four Contiguous Stereocenters
A convenient and efficient synthetic method has been
developed to construct highly functionalized polycyclic
indoline skeletons with four contiguous stereocenters
Jin-Ming Yang,a Peng-Hua Li,b Yin Wei,a Xiang-Ying
Tang,a* Min Shia,b
*
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins