Disilylation of N-(2-Halophenyl)-2-phenylacrylamides with hexamethyldisilane via trapping the spirocyclic palladacycles

Article abstract of DOI:10.1016/j.tetlet.2018.03.086

The palladium-catalyzed disilylation of the spirocyclic palladacycles with hexamethylaisilane has been realized. The key spirocyclic palladacycles are generated from N-(2-haloaryl)-2-arylacrylamide via intramolecular Heck reaction and followed remote C-H activation. A range of 3-((trimethylsilyl)methyl)-3-(2-(trimethylsilyl)phenyl)indolin-2-ones are obtained in good to excellent yields from readily available starting material under mild conditions.

Full text of DOI:10.1016/j.tetlet.2018.03.086

Accepted Manuscript
Disilylation of N-(2-Halophenyl)-2-phenylacrylamides with Hexamethyldisi-
lane via Trapping the Spirocyclic Palladacycles
Genhua Xiao, Liang Chen, Guobo Deng, Jianbing Liu, Yun Liang
PII:
S0040-4039(18)30423-4
https://doi.org/10.1016/j.tetlet.2018.03.086
TETL 49855
DOI:
Reference:
Tetrahedron Letters
To appear in:
Received Date:
Revised Date:
Accepted Date:
3 March 2018
27 March 2018
29 March 2018
Please cite this article as: Xiao, G., Chen, L., Deng, G., Liu, J., Liang, Y., Disilylation of N-(2-Halophenyl)-2-
phenylacrylamides with Hexamethyldisilane via Trapping the Spirocyclic Palladacycles, Tetrahedron Letters
(2018), doi: https://doi.org/10.1016/j.tetlet.2018.03.086
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Tetrahedron Letters
Disilylation of N-(2-Halophenyl)-2-phenylacrylamides with Hexamethyldisilane via Trapping the
Spirocyclic Palladacycles
Genhua Xiao, Liang Chen, Guobo Deng, Jianbing Liu* and Yun Liang*
National & Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources, Key Laboratory of Chemical Biology and
Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules, Hunan
Normal University, Changsha, Hunan 410081, China.
ARTICLE INFO
ABSTRACT
Article history:
Received
Received in revised form
Accepted
The palladium-catalyzed disilylation of the spirocyclic palladacycles with hexamethylaisilane has been
realized. The key spirocyclic palladacycles are generated from N-(2-haloaryl)-2-arylacrylamide via
intramolecular Heck reaction and followed remote C-H activation. A range of 3-((trimethylsilyl)methyl)-
3-(2-(trimethylsilyl)phenyl)indolin-2-ones are obtained in good to excellent yields from readily available
starting material under mild conditions.
Available online
2015 Elsevier Ltd. All rights reserved.
keywords:
Spirocyclic Palladacycles
Disilylation
Hexamethyldisilane
Domino reaction
Organosilicon compounds are a very important class of
compounds due to their application in the synthetic
chemistry,1 medicinal chemistry2 and material science.3 As a
result, substantial efforts have been directed toward the
development of efficient method for the synthesis of silicon-
containing compounds. The conventional methods for the
construction of C-Si bonds focus on straightforward
silylation of either organomagnesium or organolithium
reagents with chlorosilanes4. However, these methods suffer
from poor tolerance of functional groups and harsh reaction
conditions. Recently, significant progress for the synthesis
of organosilanes has been made in transition metal-catalyzed
silylation reactions of hexamethyldisilane.5-7 So far, two
main types of silylation reactions have been developed by
using hexamethyldisilane as silyl reagent, including C-X
silylation via classic cross-coupling reaction6 (Scheme 1, eq
1), and C-H silylation via oxidative coupling reaction
(Scheme 1, eq 2).7 Mechanistically, these coupling reactions
are initiated by the formation of C-palladium intermediate,
then trapped by hexamethyldisilane, and finally afford
----------------
* Corresponding author.
E-mail address: 1485192973@qq.com (J. Liu); liang@hunnu.edu.cn
(Y. Liang).
reaction is a big challenge. Recently, Wang reported that the
palladium carbine species (containing carbon-palladium
double bond) could be inserted by disilane to access
germinal disilanes.11 In this reaction, two C-Si bonds were
formed, and two silyls were introduced. Based on our
previous studies on palladacycle12 and silicon-containing
compounds,13 we envision that the palladacycles could be
trapped by hexamethyldisilane for the synthesis of
disilylation products (Scheme 1, eq 3). (the similar work
was reported online by Zhang14 when we prepared to submit
our manuscript.)
trimethylsilyl-containing
compounds
via
reductive
elimination of C-Si bond. Importantly, the trimethylsilyl can
conveniently convert into other functional groups (such as
halogen, hydroxyl, amino)8. Therefore, development of new
method for introducing the trimethylsilyl in organic
molecular is very significant.
Palladacycle, as an important intermediate, has been
extensively studied and found wide applications in organic
synthesis.9,10 With two C-Pd bonds, palladacycle is
conveniently used to construct
a variety of cyclic
Scheme 1. Methods for Synthesis of Trimethylsilyl Compounds
compounds.9 However, ring-opening difunctionalization
products are quite rare.10 Therefore, utilizing the two C-Pd
The initial investigation focused on the reaction of
hexamethyldisilane with N-(2-iodophenyl)-N-methyl-2-
phenylacrylamide 1a for exploring the reaction conditions
bonds
of
palladacycle
for
the
synthesis
of
difunctionalization products via ring-opening coupling

2
Tetrahedron Letters
a Reaction conditions: 1a (0.2 mmol), Hexamethyldisilane (8 equiv),
(Table 1). Fortunately, the disilylation product 2a was
Palladium catalyst (10 mol%), Ligand (20 mol%), Base (5 equiv),
obtained in 70% yield by employing Pd(OAc)2 as catalyst,
Solvent (1 mL), 90 oC, 12 h. Yields of isolated are given.
P(tBu)3 as ligand and Cs2CO3 as base in CH3CN at 90 C
o
b 110 oC.
c 70 oC.
under nitrogen atmosphere, and the structure of 2a was
proved by a single-crystal X-ray diffraction (CCDC:
1822233). Encouraged by this result, the palladium catalysts
were tested firstly, and the results indicated that the catalyst
of Pd(OAc)2 performed the best catalytic efficiency. P-
ligand free condition and the other P-ligands including PPh3,
P(o-tol)3, X-Phos, and S-Phos were examined, and PPh3 was
found to give the best result. Subsequently, a variety of
bases such as KF, K3PO4, K2CO3 and Na2CO3 were
investigated. The results shown that the base K3PO4 was the
best for this disilylation of C,C-palladacyclices. To enhance
the reaction yield, several solvents such as THF, Toluene,
DMAc and Dioxane were screened, but the yield of the
disilylation product all gave rise in lower yields than
CH3CN. Finally, the temperature screening indicated that 90
oC was the most suitable temperature for this protocol.
Therefore, the optimized reaction conditions were as
follows: 1a (0.2 mmol), hexamethyldisilane (1.6 mmol),
K3PO4 (1.0 mmol), Pd(OAc)2 (10 mol%), PPh3 (20 mol%)
in CH3CN (1 mL), at 90 oC.
Table 2. Disilylation of N-(2-Iodophenyl)-2-phenylylacrylamidesa,b
Table 1. Optimization of Reaction Conditionsa
entry
catalyst
ligand
P(tBu)3
base
solvent
yield
70%
1
Pd(OAc)2
Cs2CO3
CH3CN
2
Pd(dba)2
Pd2(dba)3
P(tBu)3
P(tBu)3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
KF
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
THF
69%
68%
65%
69%
59%
72%
68%
68%
69%
trace
78%
71%
11%
54%
trace
61%
3
4
[Pd(π-ally)Cl]2 P(tBu)3
5
Pd(PPh3)4
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
P(tBu)3
-
6
7
PPh3
X-Phos
P(o-tol)3
S-Phos
PPh3
PPh3
PPh3
PPh3
PPh3
PPh3
PPh3
PPh3
PPh3
PPh3
8
9
10
11
12
13
14
15
16
17
18
19b
20c
K3PO4
K2CO3
Na2CO3
K3PO4
K3PO4
K3PO4
K3PO4
K3PO4
K3PO4
a Reaction conditions: 1a (0.2 mmol), Hexamethyldisilane (8 equiv),
Pd(OAc)2 (10 mol%), PPh3 (20 mol%), K3PO4 (5 equiv), CH3CN (1
mL), 90 oC, 12 h.
b Isolated yields.
Toluene
DMAc
With the optimized conditions in hand, we turned our
attention to survey the substrate scope of disilylation by
using a variety of acrylamides and hexamethyldisilane, and
the results were summarized in Table 2. First,
phenylacrylamides with mono-substitution and di-
substitution on the nitrogen atom were investigated.
Satisfactorily, electron-donating substituents such as ethyl
Dioxane 56%
CH3CN
CH3CN
68%
67%
(
1b) and benzyl (1c) substrates reacted well, and delivered

a Reaction conditions: 1a (0.2 mmol), Hexmethyldisilane (8 equiv),
Pd(OAc)2 (10 mol%), PPh3 (20 mol%), K3PO4 (5 equiv), CH3CN (1
mL), 90 oC, 12 h.
the target disilylation products in 87% and 94% yield
respectively. However, the N-free and N-tosyl substituted
substrates were unfavourable to this disilylation.
Subsequently, our study focused on screening the effect of
substitutents on the 2-iodophenyl of acrylamides. It was
observed that the substrates containing electron-rich groups
such as methyl and methoxyl could smoothly transform into
the correspond products in high yields. The substrates
containing electron-poor groups such as trifluoromethyl,
fluoro, chloro, and bromo groups survived under the
standard conditions, and the corresponding products were
formed in yields ranging from 43% to 93%. Specifically, the
benzyl protecting group on the nitrogen moiety improved
the overall yield. Interesting, heterocyclic N-(3-iodopyridin-
b Isolated yields.
It is notable that the reaction can also be performed on a
gram scale, with no impact on the yield. As shown in
Scheme 2, treatment of 1.17 g (3.0 mmol) of 3c with hex-
methyldisilane (8 equiv), afforded the product 2c in 91%
yield (1.04 g).
2-yl)-N-methyl-2-phenylacrylamide gave
a
disilylation
product 2q in 60% yield. Furthermore, the compatibility of
functional groups on the phenyl linked to the double bonds
was checked. The substrates containing the electron-
donating group such as methoxyl and the electron-
withdrawing group such as fluoro (including orthor-, para-
and meta-fluoro groups) were well-tolerated, and the
corresponding products were given in perfect yields.
However, two regioisomers were generated from substrate 1u in
a ratio of 3 : 1. Notably, the electronic effect and steric effect
did not affect the yields obviously.
In order to widen the scope of substrates, aryl bromides were
screened. As shown in Table 3, the reaction results indicated the
aryl bromides were also reactive enough to undergo the
disilylation reaction. Under the standard reaction conditions, the
N-methyl and N-benzyl substituted N-(2-iodophenyl)-2-
phenylylacrylamides gave the corresponding products in 81%
and 93% yields respectively. To our delight, the substrates
bearing the electron-donating groups such as methyl and
methoxyl or the electron-withdrawing groups such as fluorine,
chlorine, nitryl and cyano all could tolerate, and the desired
disilylation products were obtained in good to excellent yields.
Scheme 2. Gram-Scale Double Silylation of 3c
To further gain insight into the mechanism, the palladacycle C
was prepared following the literature procedure.15 It is noted that
C was disilylated to give 2a in 70% yield. The experimental
result indicate that the disilylation reaction should proceed
through palladacycle intermediates. Furthermore, a crossover
experiment was carried out (Scheme 3). First, 15% of disilylation
product 2y was afforded when hexamethyldisilane was instead of
1,2-dibenzyl-tetramethyldisilane under standard conditions.
Then, the reaction of 1a with the mixture of hexamethyldisilane
and 1,2-dibenzyl-tetramethyldisilane was performed, and only
the corresponding products 2a and 2y were obtained in 50% yield
(2a:2y = 5:3; determined by 1H NMR). This result indicated that
the disilylation of the palladacycle underwent a coordinate
process.
a
Table 3. Disilylation of N-(2-Bromophenyl)-2-phenylylacrylamide
,b
Scheme 3. Control Experiments

4
Tetrahedron Letters
cooperative process. Successive studies on the detailed
mechanism and applications of the new method are
underway in our laboratory.
Acknowledgments
This work was supported by the National Natural Science
Foundation of China (21572051, 21602057), Ministry of
Education of the People's Republic of China (213027A),
Education Department of Hunan Province (15A109), Opening
Fund of Key Laboratory of Chemical Biology and Traditional
Chinese Medicine Research (Ministry of Education of China),
Hunan
Normal
University
(KLCBTCMR201707,
KLCBTCMR201708).
References and notes
1. (a) Nakao, Y.; Sahoo, A. K.; Imanaka, H.; Yada, A.; Hiyama, T.
Pure Appl. Chem. 2006, 78, 435. (b) Suzawa, K.; Ueno, M.;
Wheatley, A. E. H.; Kondo, Y. Chem. Commun. 2006, 42, 4850.
(c) Pierrat, P.; Gros, P.; Fort, Y. Org. Lett. 2005, 7, 697. (d)
Denmark, S. E.; Sweis, R. F. in Metal-Catalyzed Cross-
Coupling Reactions, Vol. 1, 2nd ed. (Eds.: De Meijere, A.;
Diederich, F.), Wiley-VCH, Weinheim, 2004. (e) Abele, E.;
Lukevics, E. Heterocycles 2002, 57, 361. (f) Langkopf, E.;
Schinzer, D. Chem. Rev. 1995, 95, 1375.
2. (a) Franz, A. K.; Wilson, S. O. J. Med. Chem. 2013, 56, 388. (b)
Mortensen, M.; Husmann, R.; Veri, E.; Bolm, C. Chem. Soc.
Rev. 2009, 38, 1002. (c) Barnes, M. J.; Conroy, R.; Miller, D. J.;
Mills, J. S.; Montana, J. G.; Pooni, P. K.; Showell, G. A.;
Walsh, L. M.; Warneck, J. B. H. Bioorg. Med. Chem. Lett.
2007, 17, 354. (d) Tacke, R.; Heinrich, T.; Bertermann, R.;
Burschka, C.; Hamacher, A.; Kassack, M. U. Organometallics
2004, 23, 4468. (e) Tacke, R.; Handmann, V.; Bertermann, I.
R.; Burschka, C.; Penka, M.; Seyfried, C. Organometallics
2003, 22, 916. (f) Showell, G. A.; Mills, J. S. Drug Discovery
Today 2003, 8, 551.
Scheme 4. Possible Mechanism for the Synthesis of 2a
Based on the present experimental results, as well as
previous reported mechanisms,5-14 the hypothetical catalytic
cycle is shown in Scheme 4. The reaction starts with
oxidative addition of Pd(0) to C-X bond, followed by a 5-
exo trig carbopalladation to form alkylpalladium(II)
intermediate
to the five-membered palladacycle
B
. Then a C-H activation step would give rise
. In general, two
C
reaction pathways [A: Pd(IV) versus B: Pd(II)-Pd(II)] for
the disilylation of hexamethyldisilane are considerable. Path
A: intermediate
the Pd(IV) intermediate
C
occurs an oxidative addition to generate
. Finally, the intermediate
D
D
undergoes double reductive elimination and affords the
product 2a. Path B: the reaction starts with oxidative
addition of Si-Si bond to Pd(0)
transmetalation-type exchange, and finally reductive
elimination of C-Si bond to afford the product 2a
The strategic utility of the trimethylsilyl was
,
followed by
.
3. (a) Mochida, K.; Shimizu, M.; Hiyama, T. J. Am. Chem. Soc.
2009, 131, 8350. (b) Bai, D.; Han, S.; Lu, Z.-H.; Wang, S. Can.
J. Chem. 2008, 86, 230. (c) Iida, A.; Nagura, K.; Yamaguchi, S.
Chem. Asian. J. 2008, 3, 1456. (d) You, Y.; An, C.-G.; Kim, J.-
J.; Park, S. Y. J. Org. Chem. 2007, 72, 6241. (e) Liu, X.-M.; He,
C.; Huang, J.; Xu, J. Chem. Mater. 2005, 17, 434. (f) Kumagai,
T.; Itsuno, S. Macromolecules 2002, 35, 5323.
demonstrated
through
selective
iodination
and
bromination,8a-8c and the corresponding products were
afforded in good yields (Scheme 5).
4. (a) Nguyen, T.-H.; Castanet, A.-S.; Mortier, J. Org. Lett. 2006,
8, 765. (b) Manoso, A. S.; Ahn, C.; Soheili, A. C.; Handy, J.;
Correia, R.; Michael Seganish, W.; DeShong, P. J. Org. Chem.
2004, 69, 8305. (c) Hartung, C. G.; Fecher, A.; Chapell, B.;
Snieckus, V. Org. Lett. 2003, 5, 1899. (d) Luliński, S.;
Serwatowski, J.; J. Org. Chem. 2003, 68, 9384. (e) Denmark, S.
E.; Neuville, L. Org. Lett., 2000, 2, 3221. (e) Denmark, S. E.;
Wehrli, D. Org. Lett., 2000, 2, 565.
5. (a) Pan, J.-L.; Chen, C.; Ma, Z.-G.; Zhou, J.; Wang, L.-R.;
Zhang, S.-Y. Org. Lett. 2017, 19, 5216. (b) Denmark, S. E.;
Kallemeyn, J. M. Org. Lett. 2003, 5, 3483. (c) Postigo, A.;
Rossi, R. A. Org. Lett. 2001, 3, 1197. (d) Suginome, M.; Ito, Y.
Chem. Rev. 2000, 100, 3221.
6. (a) McNeill, E.; Barder, T. E.; Buchwald, S. L. Org. Lett. 2007,
9, 3785. (b) Denmark, S. E.; Kallemeyn, J. M. Org. Lett. 2003,
5, 3483. (c) Postigo, A.; Rossi, R. A. Org. Lett. 2001, 3, 1197.
(d) Shirakawa, E.; Kurahashi, T.; Yoshidab, H.; Hiyama, T.
Chem. Commun. 2000, 36, 1895. (e) Tobisu, M.; Kita, Y.; Ano,
Y.; Chatani, N. J. Am. Chem. Soc. 2008, 130, 15982; (f) Tobisu,
M.; Kita, Y.; N. Chatani, J. Am. Chem. Soc. 2006, 128, 8152.
7. (a) Maji, A.; Guin, S.; Feng, S.; Dahiya, A.; Singh, V. K.; Liu,
P.; Maitia, D. Angew. Chem. Int. Ed., 2017, 56, 14903. (b) Liu,
Scheme 5. Synthetic Utility of the Silylation Products
In conclusion, we have developed the palladium-
catalyzed disilylation of the spirocyclic palladacycles with
hexamethylsilane. Furthermore, the crossover experiments
have proved that the disilylation reaction underwent a

Y.-J.; Liu, Y.-H.; Zhang, Z.-Z.; Yan, S.-Y.; Chen, K.; Shi, B.-F.
Angew. Chem. Int. Ed. 2016, 55, 13859. (c) Pan, J.-L.; Li, Q.-Z.;
Zhang, T.-Y.; Hou, S.-H.; Kang, J.-C.; Zhang, S.-Y. Chem.
Commun. 2016, 52, 13151. (d) Chen, C.; Guan, M.; Zhang, J.;
Wen, Z.; Zhao, Y. Org. Lett., 2015, 17, 3646. (e) Kanyiva, K. S.;
Kuninobu, Y.; Kanai, M. Org. Lett. 2014, 16, 1968.
Ed. 2009, 48, 572. (k) Piou, T.; Bunescu, A.; Wang, Q.;
Neuville, L.; Zhu, J.; Angew. Chem. Int. Ed. 2013, 52, 12385. (l)
Yoon, H.; Lossouarn, A.; Landau, F.; Lautens, M. Org. Lett.
2016, 18, 6324.
10. (a) Chen, D.; Shi, G.; Jiang, H.; Zhang, Y.; Zhang, Y. Org. Lett.
2016, 18, 2130. (b) Ye, J.; Shi, Z.; Sperger, T.; Yasukawa, Y.;
Kingston, C.; Schoenebeck, F.; Lautens, M. Nat. Chem. 2017, 9,
361.
11. Liu, Z.; Tan, H.; Fu, T.; Xia, Y.; Qiu, D.; Zhang, Y.; Wang, J. J.
Am. Chem. Soc. 2015, 137, 12800.
8. (a) Maji, A.; Guin, S.; Feng, S.; Dahiya, A.; Singh, V. K.; Liu,
P.; Maiti, D. Angew. Chem. Int. Ed. 2017, 129, 15099. (b)
Zarate, C.; Nakajima, M.; Martin, R. J. Am. Chem. Soc. 2017,
139, 1191. (c) Jacob, L. A.; Chen, B. L.; Stec, D. Synthesis
1993, 6, 611. (d) Lam, P. Y. S.; Deudon, S.; Averill, K. M.; Li,
R.; He, M. Y.; De Shong, P.; Clark, C. G. J. Am. Chem. Soc.
2000, 122, 7600. (e) Fleming, I.; Henning, R.; Plaut, H. J. Chem.
Soc., Chem. Commun. 1984, 29. (f) Tamao, K.; Ishida, N.;
Tanaka, T.; Kumada, M. Organometallics 1983, 2, 1694.
9. (a) Xu, S.; Chen, R.; Fu, Z.; Zhou, Q.; Zhang, Y.; Wang, J. ACS
Catal. 2017, 7, 1993. (b) Hu, T.-J.; Zhang, G.; Chen, Y.-H.;
Feng, C.-G.; Lin, G.-Q. J. Am. Chem. Soc. 2016, 138, 2897. (c)
Li, J.-Y.; Chang, H.-I.; Feng, C.-N. Wu, Y.-T. Org. Lett. 2016,
18, 6444. (d) Jiang, H.; Zhang, Y.; Chen, D.; Zhou, B.; Zhang,
Y. Org. Lett. 2016, 18, 2032. (e) Shi, G.; Chen, D.; Jiang, H.;
Zhang, Y.; Zhang, Y. Org. Lett. 2016, 18, 2958. (f) Masselot,
D.; Charmant, J. P. H.; Gallagher, T. J. Am. Chem. Soc. 2006,
128, 694. (g) Liu, Z.; Zhang, X.; Larock, R. C. J. Am. Chem.
Soc. 2005, 127, 15716. (h) Pérez-Gómez, M.; García-López, J.-
A. Angew. Chem. Int. Ed. 2016, 55, 14389. (i) Yoon, H.; Rçlz,
M.; Landau, F.; Lautens, M.; Angew. Chem. Int. Ed. 2017, 56,
10920. (j) Gerfaud, T.; Neuville, L.; Zhu, J. Angew. Chem. Int.
12. Wu, L.; Deng, G.; Liang, Y. Org. Biomol. Chem. 2017, 15,
6808.
13. (a) Liang, Y.; Geng, W.; Wei, J.; Xi, Z. Angew. Chem. Int. Ed.
2012, 51, 1934. (b) Liang, Y.; Geng, W.; Wei, J.; Ouyanga, K.;
Xi, Z. Org. Biomol. Chem. 2012, 10, 1537. (c) Liang, Y.;
Zhang, S.; Xi, Z. J. Am. Chem. Soc. 2011, 133, 9204.
14. Lu, A.; Ji, X.; Zhou, B.; Wu, Z.; Zhang, Y. Angew. Chem. Int.
Ed. 2018, 57, 3233.JJ
Supplmentary Material
Supplementary
data
(experimental
procedures
and
characterization data for all new compounds and copies of NMR
spectra) associated with this article can be found, in the online
version.
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3
Highlights:
1). Double silylation of spirocyclic palladacycles with hexamethylsilane
2). Initiated by intramolecular Heck reaction and followed remote C-H activation
3). Obtained disilylation compounds of indolinone in good to excellent yields

Tetrahedron Letters
4
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Disilylation of N-(2-Halopenyl)-
2-penylacrylamides with
Hexamethyldisilane via
Trapping the Spirocyclic
Palladacycles
Genhua Xiao, Liang Chen, Guobo Deng,
Jianbing, Liu* Yun Liang*