Rhodium-catalyzed direct C7 alkynylation of indolines

Article abstract of DOI:10.1002/adsc.201401007

An efficient rhodium(III)-catalyzed direct C7 alkynylation of indoline C-H bonds with the alkynylated hypervalent iodine reagents has been developed. This reaction proceeds smoothly under mild conditions over a wide structural scope with high site-selectivity and excellent functional-group tolerance. N-Acetyl as well as other N-acyls served as effective directing groups (DG). This procedure allows for the synthesis of a variety of 7-alkynyl-substituted indolines in good to excellent yield. More significantly, C7-alkynylated indoles through further transformations have been successfully accessed.

Full text of DOI:10.1002/adsc.201401007

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DOI: 10.1002/adsc.201401007
Rhodium-Catalyzed Direct C7 Alkynylation of Indolines
Ning Jin,a Changduo Pan,a Honglin Zhang,a Pan Xu,a Yixiang Cheng,a
and Chengjian Zhua,b,*
a
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University,
Nanjing, 210093, Peopleꢀs Republic of China
E-mail: cjzhu@nju.edu.cn
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai, 200032, Peopleꢀs
b
Republic of China
Received: October 23, 2014; Revised: January 26, 2015; Published online: && &&, 0000
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201401007.
Abstract: An efficient rhodium(III)-catalyzed direct
C7 alkynylation of indoline C H bonds with the al-
EBX under very mild conditions.[4] Very recently, in
2014, Li,[5] Loh,[6] Glorius,[7] and Chang[8] independent-
ly reported the rhodium-catalyzed alkynylation of C
À
À
kynylated hypervalent iodine reagents has been de-
veloped. This reaction proceeds smoothly under
mild conditions over a wide structural scope with
high site-selectivity and excellent functional-group
tolerance. N-Acetyl as well as other N-acyls served
as effective directing groups (DG). This procedure
allows for the synthesis of a variety of 7-alkynyl-
substituted indolines in good to excellent yield.
More significantly, C7-alkynylated indoles through
further transformations have been successfully ac-
cessed.
H bonds with TIPS-EBX.
The indoline nucleus is a prominent structural
motif found in numerous natural products and bioac-
tive compounds.[9] Particularly, C7-substituted indo-
line scaffolds are found in many pharmaceutical
agents.[10] Thus, the direct C H bond functionalization
À
of indolines at the C7 position through chelation-as-
À
sisted C H activation is synthetically attractive but
relatively rare. In the past years, considerable efforts
À
have been made to achieve direct C H bond aryla-
tion[11] or alkenylation[12] of indolines at the C7 posi-
tion (Scheme 1).
À
Keywords: alkynylation; C H activation; indolines;
iodine; rhodium
Inspired by this, our group focused on the synthesis
À
of indole and indoline derivatives via C H activa-
tion,[13] and recently, we have reported a Ru-catalyzed
C7 amidation of indolines with sulfonyl azides.[14]
Later, Chang also disclosed an Ir-catalyzed C7 amida-
Alkynes are important building blocks in synthetic or- tion of indolines by using organic azides.[15] Shortly af-
ganic chemistry and material sciences since the terwards, Kim developed a facile method for the de-
alkyne moiety has been recognized as a versatile func- carboxylative C7 acylation of indolines with a-oxocar-
tional group for facile conversion into a multitude of boxylic acids.[16] Most recently, Zhou described C7 al-
functionalities or various useful molecules.[1] In this kylation of indolines by Rh and Ir catalysis.[17] Howev-
regard, the discovery of novel and reliable methods er, to the best of our knowledge, the C7 alkynylation
for the introduction of alkynyl functionality has at- of indolines has not been reported. Herein, we de-
tracted much attention. Over the past few decades, scribed a rhodium-catalyzed direct C7 alkynylation of
À
with the surge in research on C H activation, rhodi- indolines with the alkynylated hypervalent iodine
um-catalyzed direct functionalization of C H bonds compounds.
À
has emerged as a straightforward and highly efficient
At the outset, we first investigated the reaction of
À
tool for the construction of C E bonds (E=C, N, O, N-acetylindoline (1a) with TIPS-EBX (2a) in the
or S).[2] However, rhodium-catalyzed direct C H presence of 5 mol% [RhCp*Cl2]2 and 20 mol%
À
bond alkynylation has hung behind. Notably, in 1996, AgNTf2 in DCE under an Ar atmosphere at 508C for
Zhdankin first introduced the alkynylated hypervalent 16 h. To our delight, the alkynylation product 3a was
iodine reagent 1-[(triisopropylsilyl)ethynyl]-1,2-ben- obtained in 82% yield (Table 1, entry 1). Among dif-
ziodoxol-3(1H)-one (TIPS-EBX).[3] Since then, Waser ferent solvents screened, DCM turned out to have the
developed several Au- and Pd-catalyzed direct alky- best efficiency, giving the alkynylation product 3a in
nylations of heterocycles and enolates by using TIPS- 85% isolated yield, while THF exhibited negative re-
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Ning Jin et al.
sults, and MeCN was ineffective in this reaction
(Table 1, entries 2–4). On the other hand, lower
amounts of product were formed with [RuCl2(p-
cymene)]2 (Table 1, entry 5). Meanwhile, various addi-
tives were also tested, and it was found that AgSbF6,
AgOTf and Zn(OTf)2 were also active to provide 3a
selectively, but with lower yields than AgNTf2
(Table 1, entries 7–9). In addition, the additive
CsOAc was found to be ineffective in this coupling re-
action (Table 1, entry 10). This alkynylation reaction
was also sensitive to temperature. Raising the reac-
tion temperature reduced the yield of product 3a
(Table 1, entry 11). Furthermore, screening of the
loading of rhodium catalyst and silver salt indicated
that 5 mol% [RhCp*Cl2]2 and 20 mol% of AgNTf2
were optimal (Table 1, entries 12–14). In controlled
experiments, the alkynylation product 3a was not ob-
served in absence of either [RhCp*Cl2]2 or AgNTf2,
which implied that a cationic RhIII species was re-
quired for this coupling process (Table 1, entries 15
and 16).
With the optimized reaction conditions in hand, we
began to examine the substrate scope for this novel
protocol. As shown in Table 2, the C7 alkynylation of
N-acetyl indolines proceeded well to give the desired
products in good yields irrespective of various substi-
tution patterns on the aromatic ring (3a–3h). It
should be mentioned that halogen substituted
À
Scheme 1. Direct C H bond functionalizations of indolines
at the C7 position.
Table 1. Screening conditions for the Rh-catalyzed alkynylation[a]
Entry
Catalyst (mol%)
Additive (mol%)
Solvent
T [8C]
Yield [%][b]
1
2
3
4
5
7
8
9
10
11
12
13
14
15
16
[RhCp*Cl2]2(5)
[RhCp*Cl2]2 (5)
[RhCp*Cl2]2 (5)
[RhCp*Cl2]2 (5)
[RuCl2(p-cymene)]2 (5)
[RhCp*Cl2]2 (5)
[RhCp*Cl2]2 (5)
[RhCp*Cl2]2 (5)
[RhCp*Cl2]2 (5)
[RhCp*Cl2]2 (5)
[RhCp*Cl2]2 (2.5)
[RhCp*Cl2]2(2.5)
[RhCp*Cl2]2 (5)
[RhCp*Cl2]2 (0)
[RhCp*Cl2]2 (5)
AgNTf2(20)
AgNTf2(20)
AgNTf2(20)
AgNTf2(20)
AgNTf2(20)
AgSbF6(20)
AgOTf(20)
Zn(OTf)2(20)
CsOAc(20)
AgNTf2(20)
AgNTf2(10)
AgNTf2(20)
AgNTf2(40)
AgNTf2(20)
AgNTf2(0)
DCE
THF
50
50
50
50
50
50
50
50
50
80
50
50
50
50
50
82
61
trace
85
59
80
60
22
0
64
65
69
83
0
MeCN
DCM
DCM
DCM
DCM
DCM
DCM
DCM
DCM
DCM
DCM
DCM
DCM
0
[a]
Reaction conditions: 1a (0.1 mmol), 2a (0.15 mmol), [RhCp*Cl2]2 (5 mol%), AgNTf2 (20 mol%), 4ꢂ molecular sieves
(100 mg), solvent (0.5 mL), under Ar at 508C for 16 h.
Isolated yield.
[b]
2
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Rhodium-Catalyzed Direct C7 Alkynylation
Table 2. Scope of indolines[a]
Table 3. Scope of the alkynylated hypervalent iodines[a]
Entry
Product 3
R
Yield[%][b]
1
2
3
4
5
6
3a
3r
3s
3t
3u
3v
TIPS
TMS
TES
TBDMS
Ph
85
37
45
52
Nd
Nd
tBu
[a]
Reaction conditions: 1a (0.1 mmol),
2
(0.15 mmol),
[RhCp*Cl2]2 (5 mol%), AgNTf2 (20 mol%), 4 ꢂ molecu-
lar sieves (100 mg), solvent (0.5 mL), under Ar at 508C
for 16 h.
Isolated yield.
[b]
light, TMS-EBX, TES-EBX and TBMS-EBX were
suitable for the alkynylation reaction, albeit the corre-
sponding products were obtained in moderate yields
(3r–3t). Here the reason is that TIPS-EBX has more
steric protection for the stability of product. However,
t
when Ph-EBX and Bu-EBX were used, the reaction
failed to give the desired product 3u and 3v.
Finally, in order to show the further synthetic utility
of our products, we provided a method to access C7-
alkynyl-substituted indoles (Scheme 2). Dehydrogena-
tion of 3a was performed well with the MnO2 oxi-
dant,[18] which gave 4a in 50% yield. Then, using
a well-known method,[19] we were able to remove the
directing group of 4a with DBU, which generated the
C7-alkynylated indoles 5a in 90% yield.
[a]
Reaction conditions:
1 (0.1 mmol), 2a (0.15 mmol),
[RhCp*Cl2]2 (5 mol%), AgNTf2 (20 mol%), 4 ꢂ molecu-
lar sieves (100 mg), solvent (0.5 mL), under Ar at 508C
for 16 h.
Accordingly, a plausible mechanism for this reac-
N-acetyl indolines at C5 and C6 position were well- tion has been outlined in Scheme 3. Initially, treat-
tolerated, and the bromo moiety of 3e was kept ment of [RhCp*Cl2]2 with AgNTf2 generates the
intact in the reaction course, thus providing a handle
for further transformations. This reaction also dis-
played high reactivity with C2- or C3-substituted in-
dolines, affording the corresponding products (3i–3l)
in high yields. Moreover, different directing groups
(DG) have been investigated under the optimal reac-
tion conditions. To our delight, indolines bearing
a series of N-acyl groups were compatible with the re-
action, giving the corresponding products (3m–3q) in
good yields. However, the present reaction did not
proceed when Boc- or Cbz-protecting groups were
employed as a directing group.
Next, we further explored the scope of the alkyny-
lated hypervalent iodine. TMS-EBX, TES-EBX,
TBMS-EBX, Ph-EBX and tBu-EBX were tested
Scheme 2. Dehydrogenation and removal of the directing
using 2a as the model substrate (Table 3). To our de- group.
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Experimental Section
Typical Experimental Procedure for Rh-Catalyzed
Alkynylation of Indolines:
Under Ar atmosphere,
a mixture of N-acetyindoline
(0.1 mmol), TIPS-EBX (0.15 mmol), [RhCp*Cl2]2 (5 mol%),
AgNTf2 (20 mol%), 4 ꢂ molecular sieves (100 mg), and
DCM (0.5 mL) was stirred in a sealed tube at 508C for 16 h.
After cooling to room temperature, the solvent was evapo-
rated under reduced pressure and the residue was purified
by flash column chromatography (n-hexane/ethyl acetate)
on silica gel to give the product.
Procedure for Dehydrogenation of 3a:
A mixture of the product 3a (34.1 mg, 0.1 mmol), MnO2
(173.9 mg, 2 mmol), 4 ꢂ molecular sieves (100 mg) in DCM
(2 mL) was stirred in a sealed tube at 508C for 12 h. After
cooling to room temperature, the solvent was evaporated
under reduced pressure and the residue was purified by
flash column chromatography (n-hexane/ethyl acetate) on
silica gel to give the product 4a (17 mg, 50%).
Scheme 3. Proposed mechanism.
Procedure for Removal of the Directing Group of 4a:
active cationic RhIII catalyst.[20] This active RhIII cata-
lyst coordinates to the substrate 1a, which affords the
rhodacycle intermediate I via a C-H activation. Subse-
quently, direct oxidative addition of the alkynylated
hypervalent iodine reagents 2a allows generation of
the RhV alkynyl intermediate II (Path A).[5] Then, re-
ductive elimination of intermediate II delivers the
RhIII alkyne intermediate III. Alternatively, rhodacy-
clic intermediate I may undergo regioselective migra-
tory insertion into the alkyne unit to generate an al-
kenyl-rhodacycle IV (Path B). The following a-elimi-
nation of 2-iodobenzoic acid of IV occurs to produce
a RhIII vinylidene intermediate V. Then, a concerted
or stepwise 1,2-aryl migration and elimination allows
generation of the same intermediate III.[6,7] Finally,
alkyne dissociation from III furnishes the alkynylated
product 3a together with an active RhIII benzoate cat-
To a solution of the product 4a (34.0 mg, 0.1 mmol) in meth-
anol (0.5 mL) was added DBU (30.2 mg, 0.2 mmol), and the
mixture was refluxed in a sealed tube for 16 h. After cooling
to room temperature, the solvent was evaporated under re-
duced pressure and the residue was purified by flash column
chromatography (n-hexane/ethyl acetate) on silica gel to
give the product 5a (26.7 mg, 90%).
Acknowledgements
We thank the National Natural Science Foundation of China
(No. 21372114, 21172106, 21474048, and 51173078), the Na-
tional Basic Research Program of China (2010CB923303)
and the Research Fund for the Doctoral Program of Higher
Education of China (20120091110010) for financial support.
À
alyst, which may undergo a C H activation with 1a
to regenerate intermediate I.
References
In conclusion, we have developed the first rhodi-
À
um-catalyzed direct C7 alkynylation of indoline C H
[1] a) P. Siemsen, R. C. Livingston, F. Diederich, Angew.
Chem. 2000, 112, 2740; Angew. Chem. Int. Ed. 2000, 39,
2632; b) E. Negishi, L. Anastasia, Chem. Rev. 2003,
103, 1979; c) F. Diederich, P. J. Stang, R. R. Tykwinsky
(Eds.), Acetylene Chemistry: Chemistry Biology and
Material Science, Wiley-VCH, Weinheim, 2005; d) S.
Toyota, Chem. Rev. 2010, 110, 5398; e) S. Diez-Gonza-
lez, Catal. Sci. Technol. 2011, 1, 166; f) J. P. Brand, J.
Waser, Chem. Soc. Rev. 2012, 41, 4165; g) R. Chinchil-
la, C. Najera, Chem. Rev. 2014, 114, 1783.
bonds with the alkynylated hypervalent iodine re-
agent as the alkynyl source. This present reaction is
applicable to a variety of substrates under mild condi-
tions with the features of high site-selectivity and ex-
cellent functional-group tolerance. Furthermore, this
protocol provides an efficient approach for the syn-
thesis of a range of 7-alkynyl-substituted indolines,
which are valuable for further transformations. More
importantly, we have successfully disclosed a reliable
method to access C7-alkynylated indoles.
[2] For selected recent reviews, and communications on
À
rhodium-catalyzed C H bond functionalization:
a) D. A. Colby, A. S. Tsai, R. G. Bergman, J. A.
Ellman, Acc. Chem. Res. 2011, 45, 814; b) G. Song, F.
Wang, X. Li, Chem. Soc. Rev. 2012, 41, 3651; c) F. W.
Patureau, J. Wencel-Delord, F. Glorius, Aldrichimica
4
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COMMUNICATIONS
Rhodium-Catalyzed Direct C7 Alkynylation
Acta. 2012, 45, 31; d) S. Chen, J. Yu, Y. Jiang, F. Chen,
J. Cheng, Org. Lett. 2013, 15, 4754; e) X. Li, S. Yu, F.
Wang, B. Wan, X. Yu, Angew. Chem. 2013, 125, 2637;
Angew. Chem. Int. Ed. 2013, 52, 2577; f) N. Kuhl, N.
Schrçder, F. Glorius, Adv. Synth. Catal. 2014, 356, 1443;
g) Y. Yang, W. Hou, L. Qin, J. Du, H. Feng, B. Zhou,
Y. Li, Chem. Eur. J. 2014, 20, 416; h) T. Zhang, Z. Qi,
X. Zhang, L. Wu, X. Li, Chem. Eur. J. 2014, 20, 3283;
i) K. Wu, Z. Fan, Y. Xue, Q. Yao, A. Zhang, Org. Lett.
2014, 16, 42; j) X Zhang, W. Si, M. Bao, N. Asao, Y.
Yamamoto, T. Jin, Org. Lett. 2014, 16, 4830.
Sharp, G. A. Stephenson, J. D. Williams, H. Yu, K. M.
Zimmerman, M. I. Steinberg, P. K. Jadhav, J. Med.
Chem. 2007, 50, 6443; e) B. M. Trost, M. K. Brennan,
Synthesis 2009, 3003.
[10] a) S. P. Govek, L. E. Overman, J. Am. Chem. Soc. 2001,
123, 9468; b) T. Owa, A. Yokoi, K. Yamazaki, K. Yosh-
imatsu, T. Yamori, T. Nagasu, J. Med. Chem. 2002, 45,
4913; c) R. J. Keizer, M. K. Zamacona, M. Jansen, D.
Critchley, J. Wanders, J. H. Beijnen, J. H. M. Schellens,
A. D. R. Huitema, Invest. New Drugs 2009, 27, 140;
d) Y. Ozawa, K. Kusano, T. Owa, A. Yokoi, M. Asada,
K. Yoshimatsu, Cancer Chemother. Pharmacol. 2012,
69, 1353.
[11] For selected examples, see: a) D. Kalyani, N. R.
Deprez, L. V. Desai, M. S. Sanford, J. Am. Chem. Soc.
2005, 127, 7330; b) Z. Shi, B. Li, X. Wan, J. Cheng, Z.
Fang, B. Cao, C. Qin, Y. Wang, Angew. Chem. 2007,
119, 5650; Angew. Chem. Int. Ed. 2007, 46, 5554; c) T.
Nishikata, A. R. Abela, S. Huang, B. H. Lipshutz, J.
Am. Chem. Soc. 2010, 132, 4978; d) S. De, S. Ghosh, S.
Bhunia, J. A. Sheikh, A. Bisai, Org. Lett. 2012, 14,
4466; e) L.-Y. Jiao, M. Oestreich, Chem. Eur. J. 2013,
19, 10845.
[12] For selected examples, see: a) L.-Y. Jiao, M. Oestreich,
Org. Lett. 2013, 15, 5374; b) Z. Song, R. Samanta, A. P.
Antonchick, Org. Lett. 2013, 15, 5662.
[13] For selected examples, see: a) J. Xie, Q. Xue, H. Jin, H.
Li, Y. Cheng, C. Zhu, Chem. Sci. 2013, 4, 1281; b) C.
Pan, H. Jin, X. Liu, Y. Cheng, C. Zhu, Chem.
Commun. 2013, 49, 2933; c) P. Xu, J. Xie, Q. Xue, C.
Pan, Y. Cheng, C. Zhu, Chem. Eur. J. 2013, 19, 14039;
d) C. Pan, H. Jin, P. Xu, X. Liu, Y. Cheng, C. Zhu, J.
Org. Chem. 2013, 78, 9494.
[3] a) V. V. Zhdankin, C. J. Kuehl, A. P. Krasutsky, J. T.
Bolz, A. J. Simonsen, J. Org. Chem. 1996, 61, 6547;
b) V. V. Zhdankin, P. J. Stang, Tetrahdedron 1998, 54,
10927; c) V. V. Zhdankin, P. J. Stang, Chem. Rev. 2008,
108, 5299.
[4] a) J. P. Brand, J. Charpentier, J. Waser, Angew. Chem.
2009, 121, 9510; Angew. Chem. Int. Ed. 2009, 48, 9346;
b) J. P. Brand, J. Waser, Angew. Chem. 2010, 122, 7462;
Angew. Chem. Int. Ed. 2010, 49, 7304; c) D. Fernandez
Gonzalez, J. P. Brand, J. Waser, Chem. Eur. J. 2010, 16,
9457; d) S. Nicolai, S. Erard, D. Fernandez Gonzalez, J.
Waser, Org. Lett. 2010, 12, 384; e) J. P. Brand, C. Che-
valley, J. Waser, Beilstein J. Org. Chem. 2011, 7, 565;
f) J. P. Brand, J. Waser, Org. Lett. 2012, 14, 744; g) D.
Fernandez Gonzalez, J. P. Brand, R. Mondiere, J.
Waser, Adv. Synth. Catal. 2013, 355, 1631; h) R. Frei, J.
Waser, J. Am. Chem. Soc. 2013, 135, 9620; i) Y. Li, J. P.
Brand, J. Waser, Angew. Chem. 2013, 125, 6875;
Angew. Chem. Int. Ed. 2013, 52, 6743; j) Y. Li, J.
Waser, Beilstein J. Org. Chem. 2013, 9, 1763; k) G. L.
Tolnai, S. Ganss, J. P. Brand, J. Waser, Org. Lett. 2013,
15, 112.
[5] a) F. Xie, Z. Qi, S. Yu, X. Li, J. Am. Chem. Soc. 2014,
136, 4780; b) X. Zhang, Z. Qi, J. Gao, X. Li, Org.
Biomol. Chem. 2014, 12, 9329.
[6] a) C. Feng, T.-P. Loh, Angew. Chem. 2014, 126, 2760;
Angew. Chem. Int. Ed. 2014, 53, 2722; b) C. Feng, D.
Feng, T.-P. Loh, Chem. Commun. 2014, 50, 9865.
[7] K. D. Collins, F. Lied, F. Glorius, Chem. Commun.
2014, 50, 4459.
[14] C. Pan, A. Abdukader, J. Han, Y. Cheng, C. Zhu,
Chem. Eur. J. 2014, 20, 3606.
[15] K. Shin, S. Chang, J. Org. Chem. 2014, 79, 12197.
[16] M. Kim, N. K. Mishra, J. Park, S. Han, Y. Shin, S.
Sharma, Y. Lee, E.-K. Lee, J. H. Kwak, I. S. Kim,
Chem. Commun. 2014, 50, 14249.
[17] W. Ai, X. Yang, Y. Wu, X. Wang, Y. Li, Y. Yang, B,
Zhou, Chem. Eur. J. 2014, 20, 17653.
[8] J. Jeong, P. Patel, H. Hwang, S. Chang, Org. Lett. 2014,
16, 4598.
[18] For selected oxidation of indoline to indole using
MnO2, see: a) Y. S. Lo, D. A. Walsh Jr, W. J. Welstead,
R. P. Mays, E. K. Rose, D. H. Causey, R. L. Duncan, J.
Heterocycl. Chem. 1980, 17, 1663; b) T. Chandra, S.
Zou, K. L. Brown, Tetrahedron Lett. 2004, 45, 7783.
[19] M. Chakrabarty, N. Ghosh, S. Khasnobis, M. Chakra-
barty, Synth. Commun. 2002, 32, 265.
[20] a) J. Kim, J. Kim, S. Chang, Chem. Eur. J. 2013, 19,
7328; b) J. Ryu, J. Kwak, K. Shin, D. Lee, S. Chang, J.
Am. Chem. Soc. 2013, 135, 12861; c) H. Kim, K. Shin,
S. Chang, J. Am. Chem. Soc. 2014, 136, 5904.
[9] a) D. L. Boger, C. W. Boyce, R. M. Garbaccio, J. A.
Goldberg, Chem. Rev. 1997, 97, 787; b) D. A. Horton,
G. T. Bourne, M. L. Smythe, Chem. Rev. 2003, 103, 893;
c) J. M. Ontoria, S. Di Marco, I. Conte, M. E. Di Fran-
cesco, C. Gardelli, U. Koch, V. G. Matassa, M. Poma,
C. Steinkuhler, C. Volpari, S. Harper, J. Med. Chem.
2004, 47, 6443; d) M. G. Bell, D. L. Gernert, T. A.
Grese, M. D. Belvo, P. S. Borromeo, S. A. Kelley, J. H.
Kennedy, S. P. Kolis, P. A. Lander, R. Richey, V. S.
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6 Rhodium-Catalyzed Direct C7 Alkynylation of Indolines
Adv. Synth. Catal. 2015, 357, 1 – 6
Ning Jin, Changduo Pan, Honglin Zhang, Pan Xu,
Yixiang Cheng, Chengjian Zhu*
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