Rhodium-Catalyzed Direct Oxidative C-H Acylation of 2-Arylpyridines with Terminal Alkynes: A Synthesis of Pyrido[2,1-a]isoindoles

Article abstract of DOI:10.1002/adsc.201400198

A synthesis of pyrido[2,1-a]isoindoles is reported by the rhodium-catalyzed direct oxidative CH acylation of 2-aryl pyridines with terminal alkynes. The desired products were obtained in moderate to excellent yields. This is an efficient and clean method to construct C-C/C-N bonds in one step. In addition, the effective rhodium(III) catalyst was isolated and characterized by X-ray crystallography.

Full text of DOI:10.1002/adsc.201400198

COMMUNICATIONS
DOI: 10.1002/adsc.201400198
À
Rhodium-Catalyzed Direct Oxidative C H Acylation of
2-Arylpyridines with Terminal Alkynes: A Synthesis of
Pyrido[2,1-a]isoindoles
G
Binlin Zhao,a Mengxuan Yu,a Hui Liu,a Yu Chen,a Yu Yuan,a,* and Xuejian Xieb,*
a
College of Chemistry and Chemical Engineering, Yangzhou University, 225002 Yangzhou, Peopleꢀs Republic of China
E-mail: yyuan@yzu.edu.cn
Nanjing General Hospital of Nanjing Military Command, 210002 Nanjing, Peopleꢀs Republic of China
b
E-mail: flying121988@126.com
Received: February 21, 2014; Revised: June 17, 2014; Published online: && &&, 0000
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201400198.
Abstract: A synthesis of pyrido
N
tional materials.[3] In the traditional manner, the free
radical cyclization is used frequently to construct
these motifs as a powerful strategy. In 2008, Zhang
reported by the rhodium-catalyzed direct oxidative
À
C H acylation of 2-aryl pyridines with terminal al-
kynes. The desired products were obtained in mod-
erate to excellent yields. This is an efficient and
and Huang reported the synthesis of pyridoACTHNGUTER[NNUG 2,1-a]iso-
indoles via multicomponent reaction assembly involv-
ing benzynes, respectively.[4,5] Recently, Cheng devel-
oped a new strategy using 2-arylpyridine and 2-bro-
moacetophenone catalyzed by iron (Scheme 1).[6] In
the past decades, many chemists have been interested
À
clean method to construct C C/C N bonds in one
step. In addition, the effective rhodium(III) catalyst
was isolated and characterized by X-ray crystallog-
raphy.
À
in selective oxidative C H functionalization reactions
Keywords: acylation; 2-arylpyridines; C H/C H
functionalization; rhodium; terminal alkynes
of alkynes employing Ag,[7] Fe,[8] Rh,[9] Ru,[10] Pd,[11]
Cu,[12] Au,[13] Zn,[14] Ni,[15] In,[16] Mn,[17] and Re.[18] In
most cases, extra ligands are necessary to enhance the
high activities of the catalysis. It was shown that
rhodiumACTHNUTRGNEUG(N III) chelated by many ligands such as pen-
tamethylcyclopentadiene (Cp*),[19] cyclo-1,5-octadiene
PyridoACHTUNGTRENNUNG
[2,1-a]isoindoles are very important structural (cod),[9b,d,20] and PCy3 provide effective catalysts in
[21]
motifs in many pharmaceuticals,[1] dyes,[2] and func- rhodium-catalyzed direct coupling reactions. In con-
Scheme 1. Different pathways for the synthesis of pyrido
ACHTUNGTRENNUNG
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1
ÞÞ
These are not the final page numbers!

COMMUNICATIONS
Binlin Zhao et al.
[a]
À
Table 1. Optimization of the Rh-catalyzed direct oxidative C H acylation.
Entry
Oxidant (equiv.)
Cu(OAc)2 (3)
Additive (equiv.)
Solvent
Yield [%][b]
1
2
3
4
5
6
7
8
G
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (1)
CuI (0.5)
–
DMA
DMF
DMSO
o-dichlorobenzene
o-xylene
toluene
o-xylene/DMA=1:3
o-xylene/DMA=1:3
o-xylene/DMA=1:3
o-xylene/DMA=1:3
o-xylene/DMA=1:3
o-xylene/DMA=1:3
o-xylene/DMA=1:3
o-xylene/DMA=1:3
o-xylene/DMA=1:3
o-xylene/DMA=1:3
o-xylene/DMA=1:3
45
37
30
80
83
0[c]
91
72
0
Cu(OAc)2 (3)
Cu(OAc)2 (3)
Cu(OAc)2 (3)
Cu(OAc)2 (3)
Cu(OAc)2 (3)
Cu(OAc)2 (3)
T
E
E
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
G
PhIACTHNGUETRNU(NG OAc)2 (3)
9
DDQ[d] (3)
10
11
12
13
14
15
16
17
O2
air
72
62
93
69
78
49
0
Cu
Cu
Cu
Cu
–
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
–
Cu
N
CuI (1)
0[e]
[a]
Reaction conditions: 1a (0.1 mmol), 2a (0.3 mmol), catalyst, oxidant, additive, in solvent (2.0 mL), 1408C, air.
Yield after purification.
The reaction was carried out at 1008C.
DDQ=2,3-dichloro-5,6-dicyano-1,4-benzoquinone.
The reaction was carried out under argon.
[b]
[c]
[d]
[e]
tinuation of our efforts in transition metal-catalyzed (Table 1, entry 12). However, the yield dropped to
[22]
À
C H functionalization,
herein, we report the syn- 69% when the amount of CuACTHGNUTRENNU(G OAc)2 decreased to
thesis of pyrido
[2,1-a]isoindoles based on the rhodi- 0.5 equiv. (Table 1, entry 13). Moreover it was impor-
À
um-catalyzed direct oxidative C H acylation reaction tant for high yield to add 1 equiv. of CuI in the reac-
of 2-arylpyridines with terminal alkynes in the pres- tion because Cu(I) readily coordinated with terminal
ence of copper salts under air via oxidative coupling. alkynes to generate a copper-alkyne complex.[23] No-
Our initial efforts focused on the reaction of 2-phe- tably, no reaction occurred when the atmosphere was
nylpyridine (1a) and phenylacetylene (2a) catalyzed changed from air to argon (Table 1, entry 17).
by rhodium(II) acetate dimer in N,N-dimethylaceta-
mide (DMA) at 1408C under air in the presence of oxidative acylation reaction was expanded to a variety
Cu(OAc)2 (3 equiv.) and CuI (1 equiv.). It was ob- of 2-arylpyridines (1) with phenylacetylene (2a). As
served that the reaction afforded pyrido[2,1-a]isoin- shown in Table 2, all reactions afforded the desired
Under the optimized conditions, the scope of the
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
dole (3aa) in 45% yield (Table 1, entry 1). Inspired by products in moderate to good yields. Substrates with
this result, further studies were continued in order to electron-donating groups on the aryl ring of 2-arylpyr-
find suitable reaction conditions to accomplish this idines underwent the reaction smoothly to give the
transformation. Screening of the solvents revealed corresponding products in good yields (Table 2, 3ba–
that o-xylene was a good candidate which induced an ea). Product 3ba was characterized by single X-ray
increase in yield to 83% (Table 1, entries 2–7), where- crystallography[24] (Figure 1). ortho- and meta-sub-
as the best solvent was the mixture of o-xylene and stituents on the aryl ring showed no obvious influence
DMA (1:3) due to the good solubility of the reagents on the reaction outcome (Table 2, 3da and 3ea).
in DMA (Table 1, entry 7). It was found that the
other oxidants could also give the desired products in aryl ring of 2-arylpyridines hindered the reaction, and
good yields with the exception of DDQ (Table 1, en- the pyrido[2,1-a]isoindole derivatives were formed in
tries 8–11). While the amount of Cu(OAc)2 was drop- moderate yields (Table 2, 3fa–ia). Functional groups
ped to 1 equiv., a 93% yield of 3aa could be formed such as chloro, acetyl, ester, nitro group on the aryl
Meanwhile, the electron-withdrawing groups on the
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
2
asc.wiley-vch.de
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 0000, 000, 0 – 0
ÝÝ
These are not the final page numbers!

À
COMMUNICATIONS
Rhodium-Catalyzed Direct Oxidative C H Acylation of 2-Arylpyridines
[a]
À
Table 2. Rh-catalyzed direct oxidative C H acylation with different 2-arylpyridines.
[a]
Reaction conditions: 1 (0.1 mmol), 2a (0.3 mmol), [RhACHTNUGTRNEN(UG OAc)2]2 (5 mmol%), CuHCATUNGTERN(NUNG OAc)2
(0.1 mmol), CuI (0.1 mmol), in solvent (2.0 mL), 1408C, air.
Yield after purification.
0.5 mmol of phenylacetylene.
[b]
[c]
substituted electron-donating groups on the aryl ring
of acetylenes exhibited low reactivities and only mod-
erate yields were obtained (Table 3, 3ab and 3ac). It
was thought that the electron-donating groups hin-
dered the activity of the alkynes. The meta-substituted
methyl group on the aryl ring was compatible with
the optimized reaction system, and the desired prod-
uct was obtained in excellent yield (Table 3, 3ad). The
electron-withdrawing substituted phenylacetylenes
were beneficial to the reaction (Table 3, 3ae and 3af).
Moreover, 3-ethynylpyridine (2g) and 3-ethynylthio-
phene (2h) could also react with 2-phenylpyridine
smoothly to form the desired products in moderate
yields (Table 3, 3ag and 3ah). Interestingly, aliphatic
acetylene (2i) took part in the reaction readily, and
was transformed to the corresponding product in 63%
yield (Table 3, 3ai).
Figure 1. X-ray crystal structure of product 3ba.
To gain some insights into the mechanism, we ob-
served that no product was formed under an atmos-
rings were compatible with the reaction conditions phere of argon (Table 1, entry 17). This indicated that
(Table 2, 3fa–ia). The corresponding products could oxygen in the air is necessary for the reaction. Firstly,
be applied in the additional transformations in organ- rhodium(II) acetate dimer coordinated with 2-phenyl-
ic synthesis.
pyridine in DMA at 1408C to afford the rhodiumACHTUNGTRENNUNG(III)
Next, the reactions of 2-phenylpyridine (1a) with complex A in 71% yield under an air atmosphere. It
different terminal acetylenes (2) were examined. In was found that the complex A could not be generated
contrast to the substituted 2-arylpyridines, the para- in the absence of oxygen, which showed that Rh(II)
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
3
ÞÞ
These are not the final page numbers!

COMMUNICATIONS
Binlin Zhao et al.
[a]
À
Table 3. Rh-catalyzed direct oxidative C H acylation with different terminal alkynes.
[a]
Reaction conditions: 1a (0.1 mmol), 2 (0.3 mmol), [RhACHTNUGTRNEN(UG OAc)2]2 (5 mmol%), CuHCATUNGTERN(NUNG OAc)2
(0.1 mmol), CuI (0.1 mmol), in solvent (2.0 mL), 1408C, air.
Yield after purification.
0.5 mmol of phenylacetylene.
[b]
[c]
was oxidized to RhACTHNUTRGNEU(GN III). Fortunately, the structure of the reaction was carried out under an oxygen atmos-
complex A was characterized by X-ray crystallogra- phere with 5 equiv. of H2O. Meanwhile only a trace
phy[25] (Figure 2) and NMR spectroscopy. It was ob- amount of complex A was detected under anhydrous
served that two molecules of 1a coordinated with one conditions (Scheme 2, a). Interestingly, the reaction
rhodium atom and water acted as a ligand. The water performed smoothly and the product (3aa) could be
was mainly generated from the air atmosphere be- obtained in 94% yield when rhodiumACHTUNTRGNEUNG(III) complex A
cause complex A could be formed in 87% yield when and phenylacetylene reacted under the optimized
conditions (91% yield under an anhydrous oxygen at-
mosphere). Moreover, the yield was decreased when
employing one kind of copper salt. However, no de-
sired reaction occurred when air or copper salts were
absent in the system. Meanwhile, no product was ob-
served under argon with addition of extra water
(Scheme 2, b). It was shown that oxygen took part in
the formation of the product and water in complex A
merely acted as ligand. Then 10 mmol% complex A
was tested as the catalyst in the reaction of 2-phenyl-
pyridine with phenylacetylene under the optimal con-
ditions to afford desired product in 62% yield. Fortu-
nately, the yield was increased to 88% along with the
increase of complex A to 15 mmol% (Scheme 2, c).
Furthermore, the copper-alkyne complex which was
generated from Cu(I) and alkyne[23d] could react with
complex A smoothly to get 3aa in 85% yield (82%
yield under anhydrous oxygen) (Scheme 2, d). There-
fore, rhodium
cies in this reaction and oxygen and copper salts par-
Figure 2. X-ray crystal structure of rhodiumAHCTUNGTERGUNN(N III) complex A. ticipated in the formation of the product.
ACHTUNGTRENN(UNG III) complex A is the real active spe-
4
asc.wiley-vch.de
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 0000, 000, 0 – 0
ÝÝ
These are not the final page numbers!

À
COMMUNICATIONS
Rhodium-Catalyzed Direct Oxidative C H Acylation of 2-Arylpyridines
Scheme 2. Synthesis of RhACTHNUTRGNE(NUG III) complex A and a study of its activity.
On the basis of the real active species and the pre- lent yields in the presence of copper salts. The mecha-
vious literature reports,[12g,19e,23,26] a plausible mecha- nism was investigated according to the real catalytic
À
nism of the catalytic C H acylation reaction of 2-aryl- species which was derived from the substrates and
pyridines with terminal alkynes is described in rhodium acetate. It should give a new strategy for de-
Scheme 3. Rhodium(II) acetate dimer reacted with 2- signing some new and efficient Rh-catalyzed oxidative
À
phenylpyridine and water to generate the active cata- C H activation reactions. Considering the complex
lyst A under air. Then rhodium
A
ed with copper complex B, which was formed from tailed mechanisms are underway in our laboratory.
the reaction of alkyne with Cu(I),[12g,23] to produce
complex C in the presence of oxygen according to our
experiments (Scheme 2). The target product was ob-
Experimental Section
tained with the release of a Rh(I) species. Finally, the
formed Rh(I) species was oxidized by Cu(OAc)2 to
regenerate Rh
(III) to fulfill the catalytic cycle.[19e,26]
AHCTUNGTRENNUNG
Typical Procedure
ACHTUNGTRENNUNG
In conclusion, we have developed a direct and effi-
cient rhodium-catalyzed oxidative acylation of 2-aryl-
pyridines with terminal alkynes to afford the corre-
2-Phenylpyridine 1a (15.5 mg, 0.1 mmol), [Rh
(2.2 mg, 0.005 mmol), Cu(OAc)2 (18.2 mg, 0.1 mmol), CuI
(19.1 mg, 0.1 mmol), N,N-dimethylacetamide (DMA)
ACHTUNGTRNE(NUNG OAc)2]2
AHCTUNGTRENNUNG
sponding pyridoACHTUNGTRENNUNG[2,1-a]isoindoles in moderate to excel- (1.5 mL), and o-xylene (0.5 mL) were placed into a 10-mL
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
5
ÞÞ
These are not the final page numbers!

COMMUNICATIONS
Binlin Zhao et al.
Acknowledgements
This work was supported by the Priority Academic Program
Development of Jiangsu Higher Education Institutions.
References
[1] a) S. Wang, L. Cao, H. Shi, Y. Dong, J. Sun, Y. Hu,
Chem. Pharm. Bull. 2005, 53, 67–71; b) C. M. Martꢃnez-
Viturroa, D. Domꢃnguez, Tetrahedron Lett. 2007, 48,
4707–4710; c) P. Diana, A. Martorana, P. Barraja, A.
Montalbano, G. Dattolo, G. Cirrincione, F. Dall’acqua,
A. Salvador, D. Vedaldi, G. Basso, G. Viola, J. Med.
Chem. 2008, 51, 2387–2399.
[2] N. N. Romanov, Ukr. Khim. Zhur. 1981, 1280.
[3] T. Mitsumori, M. Bendikov, O. Dautel, F. Wudl, T.
Shioya, H. Sato, Y. Sato, J. Am. Chem. Soc. 2004, 126,
16793–16803.
[4] C. Xie, Y. Zhang, P. Xu, Synlett 2008, 3115–3120.
[5] X. Huang, T. Zhang, Tetrahedron Lett. 2009, 50, 208–
211.
[6] S. Liu, X. Hu, X. Li, J. Cheng, Synlett 2013, 24, 847–
850.
[7] a) C. A. Correia, C.-J. Li, Heterocycles 2010, 82, 555–
562; b) C. He, S. Guo, J. Ke, J. Hao, H. Xu, H.-Y.
Chen, A.-W. Lei, J. Am. Chem. Soc. 2012, 134, 5766–
5769; c) C. He, J. Hao, H. Xu, Y.-P. Mo, H.-Y. Liu, J.-J.
Han, A.-W. Lei, Chem. Commun. 2012, 48, 11073–
11075; d) M. Gao, C. He, H.-Y. Chen, R.-P. Bai, B.
Cheng, A.-W. Lei, Angew. Chem. 2013, 125, 7096–7099;
Angew. Chem. Int. Ed. 2013, 52, 6958–6961; e) T. B.
Nguyen, M. Q. Tran, L. Ermolenko, A. Al-Mourabit,
Org. Lett. 2014, 16, 310–313.
À
Scheme 3. Plausible mechanism for the oxidative C H func-
tionalization of 2-phenylpyridine with a terminal alkyne.
[8] a) M. Carril, A. Correa, C. Bolm, Angew. Chem. 2008,
120, 4940–4943; Angew. Chem. Int. Ed. 2008, 47, 4862–
4865; b) S.-K. Xiang, L.-H. Zhang, N. Jiao, Chem.
Commun. 2009, 6487–6489; c) C. M. Volla, P. Vogel,
Org. Lett. 2009, 11, 1701–1704; d) P. Liu, C.-Y. Zhou, S.
Xiang, C.-M. Che, Chem. Commun. 2010, 46, 2739–
2741.
[9] a) A. D. Giuseppe, R. Castarlenas, J. J. Pꢄrez-Torrente,
M. Crucianelli, V. Polo, R. Sancho, F. J. Lahoz, L. A.
Oro, J. Am. Chem. Soc. 2012, 134, 8171–8183; b) I.
Kim, C. Lee, Angew. Chem. 2013, 125, 10207–10210;
Angew. Chem. Int. Ed. 2013, 52, 10023–10026; c) M.
Castaing, S. L. Wason, B. Estepa, J. F. Hooper, M. C.
Willis, Angew. Chem. 2013, 125, 13522–13525; Angew.
Chem. Int. Ed. 2013, 52, 13280–13283; d) J. Hara, M.
Ishida, M. Kobayashi, K. Noguchi, K. Tanaka, Angew.
Chem. 2014, 126, 3000–3003; Angew. Chem. Int. Ed.
2014, 53, 2956–2959.
[10] a) J. L. Paih, S. Derien, P. H. Dixneuf, Chem. Commun.
1999, 1437–1438; b) J. L. Paih, F. Monnier, S. Derien,
P. H. Dixneuf, E. Clot, O. Eisenstein, J. Am. Chem.
Soc. 2003, 125, 11964–11975; c) K. Cheng, B.-B. Yao, J.-
L. Zhao, Y.-H. Zhang, Org. Lett. 2008, 10, 5309–5312;
d) M. Zhang, H.-F. Jiang, H. Neumann, M. Beller, P. H.
Dixneuf, Angew. Chem. 2009, 121, 1709–1712; Angew.
Chem. Int. Ed. 2009, 48, 1681–1684; e) M.-H. Xie, M.
Wang, C.-D. Wu, Inorg. Chem. 2009, 48, 10477–10479;
f) M. Zhang, H. Jiang, P. H. Dixneuf, Adv. Synth. Catal.
Schlenk tube equipped with a reflux condenser. Then, the
temperature was increased to 1408C. Phenylacetylene 2a
(30.6 mg, 0.3 mmol) was dissolved in DMA (0.5 mL), which
was added in batches over five hours. After finishing the ad-
dition, the solution was stirred under an air atmosphere at
1408C for another 1 h and monitored by TLC. After cooling
to room temperature, the reaction mixture was quenched
with ethyl acetate (15 mL) and washed with water (30 mL).
The aqueous phase was extracted twice with EtOAc (3ꢂ
10 mL), and the combined organic layer was dried over an-
hydrous Na2SO4. After evaporation of the solvents under
vacuum, the crude product was purified by column chroma-
tography on aluminum oxide to give desired product 3aa as
a
yellow solid; yield: 25.2 mg (93%); mp 112–1158C.
1H NMR (600 MHz, CDCl3): d=10.61 (d, J=7.0 Hz, 1H),
8.19 (d, J=8.5 Hz, 1H), 8.07 (d, J=7.9 Hz, 1H), 7.67 (d, J=
7.1 Hz, 2H), 7.55 (t, J=7.3 Hz, 1H), 7.52–7.49 (m, 3H), 7.35
(t, J=6.9 Hz, 1H), 7.25–7.18 (m, 2H), 6.82 (d, J=8.3 Hz,
1H); 13C NMR (150 MHz, CDCl3): d=182.24, 141.50,
133.83, 131.48, 129.12, 128.36, 127.53, 127.17, 127.09, 124.20,
120.25, 118.90, 118.67, 118.19, 117.39, 116.20, 113.10; IR
(KBr): n=3059, 1585, 1562, 1522, 1457, 1434, 1312, 1268,
1218, 1022, 964, 794, 759, 690, 616, 437 cmÀ1; HR-MS: m/z=
271.1005, calculated for C19H13NO: 271.0997.
6
asc.wiley-vch.de
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 0000, 000, 0 – 0
ÝÝ
These are not the final page numbers!

À
COMMUNICATIONS
Rhodium-Catalyzed Direct Oxidative C H Acylation of 2-Arylpyridines
2009, 351, 1488–1494; g) S. Garcia-Rubin, C. Gonzalez-
Rodriguez, C. Garcia-Yebra, J. A. Varela, M. A. Ester-
uelas, C. Saa, Angew. Chem. 2014, 126, 1872–1875;
Angew. Chem. Int. Ed. 2014, 53, 1841–1844.
[16] a) M. Nakamura, K. Endo, E. Nakamura, J. Am. Chem.
Soc. 2003, 125, 13002–13003; b) C.-C. Malakar, B.-U. W.
Maes, K.-A. Tehrani, Adv. Synth. Catal. 2012, 354,
3461–3467.
[17] a) W.-K. Chan, C.-M. Ho, M.-K. Wong, C.-M. Che, J.
Am. Chem. Soc. 2006, 128, 14796–14797; b) B.-W.
Zhou, H. Chen, C.-Y. Wang, J. Am. Chem. Soc. 2013,
135, 1264–1267.
[11] a) M. Eckhardt, G. C. Fu, J. Am. Chem. Soc. 2003, 125,
13642–13643; b) G. Altenhoffa, S. Wꢅrtzb, F. Glorius,
Tetrahedron Lett. 2006, 47, 2925–2928; c) L. Zhou, L.
Chen, R. Skouta, H.-F. Jiang, C.-J. Li, Org. Biomol.
Chem. 2008, 6, 2969–2977; d) M. Chen, X.-L. Zheng,
W.-Q. Li, J. He, A.-W. Lei, J. Am. Chem. Soc. 2010,
132, 4101–4103; e) L. Yang, L. Zhao, C.-J. Li, Chem.
Commun. 2010, 46, 4184–4186; f) S. H. Kim, J. Yoon, S.
Chang, Org. Lett. 2011, 13, 1474–1477; g) Y. Weng, B.
Cheng, C. He, A.-W. Lei, Angew. Chem. 2012, 124,
9685–9689; Angew. Chem. Int. Ed. 2012, 51, 9547–9551;
h) C. He, J. Ke, H. Xu, A.-W. Lei, Angew. Chem. 2013,
125, 1567–1570; Angew. Chem. Int. Ed. 2013, 52, 1527–
1530; i) X.-M. Jie, Y.-P. Shang, P. Hu, W.-P. Su, Angew.
Chem. 2013, 125, 3718–3721; Angew. Chem. Int. Ed.
2013, 52, 3630–3633.
[12] a) Z. Li, C.-J. Li, J. Am. Chem. Soc. 2004, 126, 11810–
11811; b) Z. Li, C.-J. Li, Org. Lett. 2004, 6, 4997–4999;
c) L. Zhao, C.-J. Li, Angew. Chem. 2008, 120, 7183–
7186; Angew. Chem. Int. Ed. 2008, 47, 7075–7078; d) T.
Hamada, X. Ye, S. S. Stahl, J. Am. Chem. Soc. 2008,
130, 833–835; e) C. Zhang, N. Jiao, J. Am. Chem. Soc.
2010, 132, 28–29; f) Y. Wei, H.-Q. Zhao, J. Kan, W.-P.
Su, M.-C. Hong, J. Am. Chem. Soc. 2010, 132, 2522–
2523; g) L.-L. Chu, F.-L. Qing, J. Am. Chem. Soc. 2010,
132, 7262–7263; h) C. A. Correia, C.-J. Li, Adv. Synth.
Catal. 2010, 352, 1446–1450; i) C. J. Pierce, H. Yoo,
C. H. Larsen, Adv. Synth. Catal. 2013, 355, 3586–3590;
j) L.-H. Zou, A. J. Johansson, E. Zuidema, C. Bolm,
Chem. Eur. J. 2013, 19, 8144–8152.
[13] a) R. Knorr, Chem. Rev. 2004, 104, 3795–3849; b) G. Li,
L. Zhang, Angew. Chem. 2007, 119, 5248–5251; Angew.
Chem. Int. Ed. 2007, 46, 5156–5159; c) N. D. Shapiro,
F. D. Toste, J. Am. Chem. Soc. 2007, 129, 4160–4161;
d) J. Dheur, M. Sauthier, Y. Castanet, A. Mortreux,
Adv. Synth. Catal. 2007, 349, 2499–2506; e) T. Haro, C.
Nevado, J. Am. Chem. Soc. 2010, 132, 1512–1513.
[14] a) G. Gao, D. Moore, R.-G. Xie, L. Pu, Org. Lett. 2002,
4, 4143–4146; b) Z.-Q. Xu, R. Wang, J.-K. Xu, C.-S. Da,
W.-J. Yan, C. Chen, Angew. Chem. 2003, 115, 5925–
5927; Angew. Chem. Int. Ed. 2003, 42, 5747–5749; c) T.
Fang, D.-M. Du, S.-F. Lu, J.-X. Xu, Org. Lett. 2005, 7,
2081–2084; d) T. Sugiishi, H. Nakamura, J. Am. Chem.
Soc. 2012, 134, 2504–2507.
[18] Y. Kuninobu, A. Kawata, K. Takai, Org. Lett. 2005, 7,
4823–4825.
[19] a) F. W. Patureau, T. Besset, N. Kuhl, F. Glorius, J. Am.
Chem. Soc. 2011, 133, 2154–2156; b) N. Schrçder, J.
Wencel-Delord, F. Glorius, J. Am. Chem. Soc. 2012,
134, 8298–8301; c) S. Sharma, E. Park, J. Park, I. S.
Kim, Org. Lett. 2012, 14, 906–909; d) Y.-X. Yang, B.
Zhou, Y.-C. Li, Adv. Synth. Catal. 2012, 354, 2916–
2920; e) J.-X. Dong, Z. Long, F.-J. Song, N.-J. Wu, Q.
Guo, J.-B. Lan, J.-S. You, Angew. Chem. 2013, 125,
608–612; Angew. Chem. Int. Ed. 2013, 52, 580–584;
f) R. Zeng, S.-Z. Wu, C.-L. Fu, S.-M. Ma, J. Am. Chem.
Soc. 2013, 135, 18284–18287; g) P. Becker, D. L. Prieb-
benow, R. Pirwerdjan, C. Bolm, Angew. Chem. 2014,
126, 273–275; Angew. Chem. Int. Ed. 2014, 53, 269–271.
[20] a) Z. Ye, W. Wang, F. Luo, S. Zhang, J. Cheng, Org.
Lett. 2009, 11, 3974–3977; b) G. Danoun, P. Mamone,
L. J. Gooßen, Chem. Eur. J. 2013, 19, 17287–17290.
[21] H. U. Vora, A. P. Silvestri, C. J. Engelin, J.-Q. Yu,
Angew. Chem. 2014, 126, 2721–2724; Angew. Chem.
Int. Ed. 2014, 53, 2683–2686.
[22] a) Y. Yuan, D.-T. Chen, X.-W. Wang, Adv. Synth. Catal.
2011, 353, 3373–3379; b) Y. Han, X.-H. Wang, X.-W.
Wang, L.-Z. Lv, G.-W. Diao, Y. Yuan, Synthesis 2012,
44, 3027–3032; c) X.-W. Wang, Y.-J. Li, Y. Yuan, Syn-
thesis 2013, 45, 1247–1255.
[23] a) N. Sh. Pirguliyev, V. K. Brel, N. S. Zefirov, P. J. Stang,
Tetrahedron 1999, 55, 12377–12386; b) K. Osakada, T.
Yamamoto, Coord. Chem. Rev. 2000, 198, 397–399;
c) R. Chinchilla, C. Nꢆjera, Chem. Rev. 2007, 107, 874–
922; d) D. Gallego, A. Brꢅck, E. Irran, F. Meier, M.
Kaupp, M. Driess, J. F. Hartwig, J. Am. Chem. Soc.
2013, 135, 15617–15626.
[24] CCDC 982184 contains the supplementary crystallo-
graphic data for this paper. These data can be obtained
free of charge from The Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
[25] CCDC 982185 contains the supplementary crystallo-
graphic data for this paper. These data can be obtained
free of charge from The Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
[26] a) A. Seoane, N. Casanova, N. Quinones, J.-L. Mascare-
nas, M. Gulias, J. Am. Chem. Soc. 2014, 136, 834–837;
b) G.-Y. Song, F. Wang, X.-W. Li, Chem. Soc. Rev.
2012, 41, 3651–3678; c) T. Satoh, M. Miura, Chem. Eur.
J. 2010, 16, 11212–11222.
[15] a) O. Vechorkin, D. Barmaz, V. Proust, X.-L. Hu, J.
Am. Chem. Soc. 2009, 131, 12078–12079; b) W.-Y. Yin,
C. He, M. Chen, H. Zhang, A.-W. Lei, Org. Lett. 2009,
11, 709–712; c) N. Matsuyama, M. Kitahara, K. Hirano,
T. Satoh, M. Miura, Org. Lett. 2010, 12, 2358–2361.
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
7
ÞÞ
These are not the final page numbers!

COMMUNICATIONS
À
8 Rhodium-Catalyzed Direct Oxidative C H Acylation of 2-
Arylpyridines with Terminal Alkynes: A Synthesis of
PyridoACHTUNGTRENNUNG[2,1-a]isoindoles
Adv. Synth. Catal. 2014, 356, 1 – 8
Binlin Zhao, Mengxuan Yu, Hui Liu, Yu Chen, Yu Yuan,*
Xuejian Xie*
8
asc.wiley-vch.de
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 0000, 000, 0 – 0
ÝÝ
These are not the final page numbers!