Selective Csp2-Csp bond cleavage: The nitrogenation of alkynes to amides

Article abstract of DOI:10.1002/anie.201303376

Breakthrough: A novel catalyzed direct highly selective C sp 2-C _sp bond functionalization of alkynes to amides has been developed. Nitrogenation is achieved by the highly selective C sp 2-C_sp bond cleavage of aryl-substituted alkynes. The oxidant-free and mild conditions and wide substrate scope make this method very practical. Copyright

Full text of DOI:10.1002/anie.201303376

.
Angewandte
Communications
DOI: 10.1002/anie.201303376
À
C C Bond Cleavage
À
Selective Csp2 Csp Bond Cleavage: The Nitrogenation of Alkynes to
Amides**
Chong Qin, Peng Feng, Yang Ou, Tao Shen, Teng Wang, and Ning Jiao*
À
Chemical bond cleavage is a fundamental process in organic
first direct Csp2 Csp bond functionalization of alkynes through
a nitrogenation process to amides, which is one of the most
important organic functional groups in natural products and
pharmaceuticals[8] (Scheme 1b).
transformation.[1] Compared to traditional C X (X = halo-
À
À
À
gen), C M (M = metal), and C Y (Y= O, N, S, P) bond
[2]
[3]
À
À
cleavage, C H and C C bond cleavage and thus associ-
ated transformations are much more challenging owing to the
unreactivity and ubiquity of these bonds. Although there has
been significant developments in this area in the recent
decades, there is still scope for the discovery of novel
Initially, we examined the transformation of 1,2-diphenyl-
ethyne (1a) to N,2-diphenylacetamide (2a) in the presence of
TFA and TMSN3, as a nitrogen source,[9] in DCE (Table 1). A
screen of transition metal catalysts showed that [PPh3AuCl]/
Ag2CO3 was more efficient than AuCl3, PtCl4, and other metal
salts (Table 1, entries 1–5). A better yield was obtained with
[PPh3AuCl]/Ag(CF3CO2), thus indicating that the active gold
catalytic species should be PPh3Au(CF3CO2) (see the Sup-
À
À
reactions through direct C H or C C functionalization.
À
À
Owing to the inertness of C C bonds and competing C H
À
activation, examples of C C bond activation are much less
[4,5]
À
common, with the exception of strained C C bonds.
For
À
C C bond cleavage of unstrained molecules, special driving
forces such as chelation assistants are required to generate
Table 1: Direct transformation of 1,2-diphenylethyne 1a to amide 2a.[a]
stable intermediates.[6] Among the reported C C s-bond
À
cleavages, a notable achievement is transition-metal-medi-
À
À
ated cleavage of Csp2 Csp bonds, in which strong C C s-bonds
can be cleaved without the aid of ring strain or extra
À
coordinating groups. Despite significant developments, Csp2
À
C
sp bond cleavages are mostly restricted to aryl cyano bonds
Entry
Catalyst
Acid
Solvent
Yield of
(Scheme 1a).[7] In comparison, catalytic aryl alkyne Csp2 Csp
bond cleavage has rarely been reported. Herein, we report the
À
À
2a [%][b]
1
2
3
4
5
6
7
8
AuCl3
PtCl4
[PPh3AuCl]/Ag2CO3
Cu(OAc)2
CoCl2
TFA
TFA
TFA
TFA
TFA
TFA
TFA
TFA
–
TfOH
H(NTf)2
HOAc
–
TFA
TFA
TFA
TFA
TFA
TFA
TFA
TFA
TFA
DCE
DCE
DCE
DCE
DCE
DCE
DCE
DCE
DCE
DCE
DCE
DCE
TFA
PhCl
HOAc
DCE
DCE
DCE
DCE
DCE
DCE
DCE
0
0
52
0
13
0
9
–
[PPh3AuCl]
Ag2CO3
0
9
PPh3AuCl/Ag2CO3
[PPh3AuCl]/Ag2CO3
[PPh3AuCl]/Ag2CO3
[PPh3AuCl]/Ag2CO3
[PPh3AuCl]/Ag2CO3
[PPh3AuCl]/Ag2CO3
[PPh3AuCl]/Ag2CO3
[PPh3AuCl]/Ag2CO3
[PPh3AuCl]/Ag2CO3
[XPhosAuCl]/Ag2CO3
[JohnPhosAuCl]/Ag2CO3
[IPrAuCl]/Ag2CO3
[IMesAuCl]/Ag2CO3
[(4-CF3C6H4)PAuCl]/Ag2CO3
<5
15
10
<5
45
31
15
72
89
43
35
52
41
66
10
11
12
13
14
15
16[c]
17[c,d]
18[c]
19[c]
20[c]
21[c]
22[c]
À
Scheme 1. Transition-metal-catalyzed cleavage of Csp2 Csp bonds.
FG=functional group.
[*] C. Qin, P. Feng, Y. Ou, T. Shen, T. Wang, Dr. N. Jiao
State Key Laboratory of Natural and Biomimetic Drugs
School of Pharmaceutical Sciences, Peking University
Xue Yuan Rd. 38, Beijing 100191 (China)
E-mail: jiaoning@bjmu.edu.cn
Homepage: http://sklnbd.bjmu.edu.cn/index.html
Dr. N. Jiao
State Key Laboratory of Organometallic Chemistry
Chinese Academy of Sciences, Shanghai 200032 (China)
[a] Reaction conditions: 1a (0.5 mmol), catalyst (0.05 mmol), TMSN3
(1.0 mmol), H2O (1.0 mmol), acid (200 mL) in solvent (2 mL), stirred at
608C. [b] Yield of the isolated product. [c] Two portions of TMSN3
(0.5 mmol each time) were added, once every 2 h. [d] [PPh3AuCl]
(20 mol%) and Ag2CO3 (20 mol%) were used. DCE=1,2-dichloro-
ethane, IMes=1,3-di(2,4,6-trimethylphenyl)imidazolin-2-ylidene,
IPr=N,N’-bis(2,6-(diisopropyl)phenyl)imidazol-2-ylidene, JohnPhos=2-
(di-tert-butylphosphino)biphenyl, Tf=trifluoromethanesulfonyl, TFA=
Trifluoroacetic acid, TMS=trimethylsilyl, Xphos=2-dicyclohexylphos-
phino-2’,4’,6’-triisopropylbiphenyl.
[**] Financial support from the National Basic Research Program of
China (973 Program) (Grant No. 2009CB825300), the National
Science Foundation of China (No. 21172006), and the Ph.D.
Programs Foundation of the Ministry of Education of China (No.
20120001110013) are greatly appreciated. We thank Yizhi Yuan for
reproducing the results of 4 f and 4i in Table 3.
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/anie.201303376.
7850
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2013, 52, 7850 –7854

Angewandte
Chemie
Table 2: Direct transformation of diaryl alkynes 1 to amides 2.[a]
porting Information, Table S1, entry 8). However, consider-
ing the cost, we choose to use Ag2CO3 as co-catalyst. Control
experiments indicated that [PPh3AuCl] is essential for this
transformation (Table 1, entry 6). In contrast to the Au
catalyst, when the Ag catalyst was used alone this amide
formation did not occur. Besides, only a trace amount of
desired product was detected when the reaction was per-
formed in the absence of TFA (Table 1, entry 9). Reactions in
which either HOTf, HN(Tf)2, or HOAc were used as an acid
additive did not give good results (Table 1, entries 10–12). We
also investigated the use of PhCl and HOAc as the solvent.
However, this resulted in low yields (Table 1, entries 13–15).
The reactivity of other gold catalysts with different ligands
(XPhos, JohnPhos, IPr, IMes, (4-CF3C6H4)3P) were also
investigated. Unfortunately, these catalysts gave poor results
(entries 18–22). After extensive screening on other parame-
ters (see the Supporting Information, Table S1), the optimum
reaction conditions were determined as: alkynes (0.5 mmol,
1.0 equiv), [PPh3AuCl] (10 mol%), Ag2CO3 (10 mol%),
TMSN3 (2.0 equiv, added in two portions), H2O (2.0 equiv),
TFA (200 mL), DCE (2 mL), 608C.
Entry Alkynes 1
Amides 2
Yield
[%][b]
1
2
3
4
72
74
42
56
The scope of the substrates were investigated under the
optimized conditions (Table 2). A variety of 1,2-diarylethynes
were found to be compatible with this protocol. Substituted
N,2-diphenylacetamides were generated through the cleavage
5
67
35
43
6[c]
À
of Csp Csp2 bonds of diarylethynes. Reactions of diarylethynes
bearing electron-donating substituents (Me, OMe, and nBu)
on the aryl ring afforded the desired products 2b, 2c, and 2d,
respectively, in moderate yields (74%, 42%, and 56%,
respectively). When diarylethynes with both electron-rich
and electron-poor aromatic substituents were employed, the
azide anion preferred to add at the electron-rich side of the
alkynes, thus leading to a low regioselectivity (see the
Supporting Information). Significantly, in addition to diaryl-
ethynes, alkyl-substituted phenylethynes, such as but-1-yn-1-
ylbenzene (1 f), 1-methoxy-4-(oct-1-yn-1-yl)benzene (1g), 1-
(cyclohexylethynyl)-4-methoxybenzene (1h), and 1-methoxy-
4-(5-phenylpent-1-yn-1-yl)benzene (1i) also gave the desired
7
8[d]
9[d]
10
44
47
0
[a] Reaction conditions: 1 (0.5 mmol), [PPh3AuCl] (0.05 mmol), Ag2CO3
(0.05 mmol), TMSN3 (1.0 mmol), H2O (1.0 mmol), TFA (200 mL) in DCE
(2 mL), stirred at 608C. [b] Yield of the isolated product. [c] HOTf
(5.2 mmol) was used instead of TFA. [d] 0.5 mmol TMSN3 was used.
À
amide products through highly selective Csp2 Csp bond
cleavage (Table 2, entries 6–9). The possible amide products
À
from Csp3 Csp bond cleavage were not detected in these cases.
Unfortunately, electron-deficient internal alkyne ethyl 3-
phenylpropiolate (1j) did not react under these conditions.
When the reactions of terminal alkynes were tested under
the optimized conditions, the reaction of 3a in TFA produced
the desired amide 4a in 70% yield (Table 3, entry 1). Based
on this result, TFA was chosen as the solvent for the reaction
of terminal alkynes. A variety of phenylethynes were con-
verted into the desired products in modest to good yields (up
to 93%, Table 3). Various substituents, including electron-
donating groups, such as methyl (4c and 4k), methoxy (4b, 4j
and 4l), tert-butyl (4g), and phenyl (4h), and electron-
withdrawing groups, such as fluoride (4d and 4m), carboxyl
(4i), were tolerated at the meta, ortho, and para positions of
the aromatic ring. Halogens were tolerated on the aromatic
ring (4d, 4e, 4 f, 4j, and 4m), thus offering an opportunity for
further cross-coupling, and facilitating the expedient synthesis
of complex compounds. Notably, the carboxylic acid group of
N-phenylacetamide 4i was also tolerated in this transforma-
tion (Table 3, entry 9).
To elucidate the mechanism, possible intermediates were
investigated. As ketones were detected as a by-product in this
reaction, we assumed that one possible pathway is a tandem
process involving gold-catalyzed hydration of alkynes to
ketones[10] and a subsequent Schmidt reaction.[11] To verify
this possibility, the reaction of 1a in the absence of TMSN3
was studied, and 1,2-diphenylethanone (5) was indeed
obtained in 73% yield (Scheme 2a). However, 5 failed to
be converted into 2a under the standard reaction conditions
(Scheme 2b). Thus, ketones are probably not a key inter-
mediate in this transformation.
Gold catalysts are one of the most effective catalysts for
electrophilic activation of alkynes toward a variety of
nucleophiles.[12] In a simplified form, nucleophilic attack on
Angew. Chem. Int. Ed. 2013, 52, 7850 –7854
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
7851

.
Angewandte
Communications
Table 3: Direct transformation of phenylacetylenes 3 to acetanilides 4.
reactions in the absence of either [PPh3AuCl] or Ag2CO3 gave
83% and 84% yield of 4a, respectively (see the Supporting
Information). All these results indicate that gold and silver
salts are not involved in the second step.
To further explore the reaction mechanism, the progress
of the reaction of phenylacetylene was monitored by 1H NMR
spectroscopy (Figure 1). The signal corresponding to the
Entry
Product
Yield [%][b]
1
2
3
4
5
6
7
8
9
R=H
4a
4b
4c
4d
4e
4 f
4g
4h
4i
70
78
52
81
92
93
66
69
52
R=OMe
R=Me
R=F
R=Cl
R=Br
R=tBu
R=Ph
R=COOH
10
4j
72
11
12
4k
4l
59
55
Figure 1. Reaction monitoring by NMR spectroscopy. A=olefinic
hydrogen in 6. B=alkynyl hydrogen in 3a. C=methyl group in 4a.
13
4m
69
olefinic hydrogen in (1-azidovinyl)benzene (6; d = 5.63 and
5.25, J = 3.2 Hz in CDCl3) appeared at 15 min after the
reaction started. This signal became strong at the early stage
and disappeared by the end of the reaction. The consumption
of 3a and production of 4a were also observed in the
spectrum as the reaction proceeded. These results strongly
indicate that azidoethene is an intermediate of this trans-
formation.
[a] Reaction conditions: 1 (0.5 mmol), [PPh3AuCl] (0.05 mmol), Ag2CO3
(0.05 mmol), TNSN3 (1.0 mmol), H2O (1.0 mmol), TFA (2 mL), stirred
at 608C.[b] Yield of the isolated product.
On the basis of the above results, a proposed mechanism is
illustrated in Scheme 3. Initially, alkyne is activated by
Scheme 2. Mechanistic studies and control experiments.
the gold-activated alkyne proceeds to give trans alkenyl gold
complexes as intermediates.[13] Therefore, it seems reasonable
that a gold-catalyzed nucleophilic attack by an azide anion
occurs in the initial stage of this transformation. To obtain
data to support mechanism, (1-azidovinyl)benzene 6 was
synthesized and subjected to the standard reaction conditions
(Scheme 2c); as expected, 4a (85% yield) was obtained.
Notably, in the absence of [PPh3AuCl] and Ag2CO3, 6 was
converted into 4a in a 81% yield (Scheme 2d). Moreover, the
Scheme 3. Proposed mechanism.
7852
www.angewandte.org
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2013, 52, 7850 –7854

Angewandte
Chemie
Int. Ed. 2009, 48, 6320; e) T. Seiser, N. Cramer, J. Am. Chem. Soc.
cationic gold(I) A generated in situ from [PPh3AuCl] and
Ag2CO3.[14] Subsequent attack of intermediate B by an azide
anion produces complexe C. The protolysis of C produces
alkenyl azide D. Further protonation of D forms resonance
azide cations E1 and E2, which could transform to amide F
through an acid-catalyzed rearrangement process.[15] It should
be noted that the electrophiles Au+ and H+ add preferentially
2010, 132, 5340; f) T. Seiser, N. Cramer, Chem. Eur. J. 2010, 16,
3383; g) T. Wang, C.-H. Wang, J. Zhang, Chem. Commun. 2011,
47, 5578; h) L. Zhou, F. Ye, Y. Zhang, J. Wang, Org. Lett. 2012,
14, 922; i) B.-L. Lu, M. Shi, Angew. Chem. 2011, 123, 12233;
Angew. Chem. Int. Ed. 2011, 50, 12027.
[6] a) C.-H. Jun, H. Lee, J. Am. Chem. Soc. 1999, 121, 880; b) N.
Chatani, Y. Ie, F. Kakiuchi, S. Murai, J. Am. Chem. Soc. 1999,
121, 8645; c) C.-H. Jun, D.-Y. Lee, H. Lee, J.-B. Hong, Angew.
Chem. 2000, 112, 3214; Angew. Chem. Int. Ed. 2000, 39, 3070;
d) C.-H. Jun, C. W. Moon, D.-Y. Lee, Chem. Eur. J. 2002, 8, 2422;
e) Y. J. Park, J.-W. Park, C.-H. Jun, Acc. Chem. Res. 2008, 41,
222; f) H. Li, Y. Li, X.-S. Zhang, K. Chen, X. Wang, Z.-J. Shi, J.
Am. Chem. Soc. 2011, 133, 15244; g) Z.-Q. Lei, H. Li, Y. Li, X.-S.
Zhang, K. Chen, X. Wang, J. Sun, Z.-J. Shi, Angew. Chem. 2012,
124, 2744; Angew. Chem. Int. Ed. 2012, 51, 2690; h) J. Wang, B.
Liu, H. Zhao, J. Wang, Organometallics 2012, 31, 8598; i) J.
Wang, W. Chen, S. Zuo, L. Liu, X. Zhang, J. Wang, Angew.
Chem. 2012, 124, 12500; Angew. Chem. Int. Ed. 2012, 51, 12334;
j) J. P. Lutz, C. M. Rathbun, S. M. Stevenson, B. M. Powell, T. S.
Boman, C. E. Baxter, J. M. Zona, J. B. Johnson, J. Am. Chem.
Soc. 2012, 134, 715.
[7] a) M. Tobisu, Y. Kita, N. Chatani, J. Am. Chem. Soc. 2006, 128,
8152; b) Y. Nakao, A. Yada, S. Ebata, T. Hiyama, J. Am. Chem.
Soc. 2007, 129, 2428; c) F. L. Taw, A. H. Mueller, R. G. Bergman,
M. Brookhart, J. Am. Chem. Soc. 2003, 125, 9808; d) M. Tobisu,
R. Nakamura, Y. Kita, N. Chatani, J. Am. Chem. Soc. 2009, 131,
3174; e) D.-G. Yu, M. Yu, B.-T. Guan, B.-J. Li, Y. Zheng, Z.-H.
Wu, Z.-J. Shi, Org. Lett. 2009, 11, 3374; f) M. R. Grochowski, T.
Li, W. W. Brennessel, W. D. Jones, J. Am. Chem. Soc. 2010, 132,
12412; g) K. Nakai, T. Kurahashi, S. Matsubara, J. Am. Chem.
Soc. 2011, 133, 11066; h) M. R. Grochowski, J. Morris, W. W.
Brennessel, W. D. Jones, Organometallics 2011, 30, 5604; i) M.
Tobisu, H. Kinuta, Y. Kita, E. Remond, N. Chatani, J. Am.
Chem. Soc. 2012, 134, 115.
À
at the less substituted carbon atoms of the unsaturated C C
triple and double bonds, respectively, (in intermediates B and
D) in accordance with Markovnikovꢀs rule.[16] In the rear-
rangement step, the migratory aptitude of aryl groups is
higher than that of alkyl groups. These two facts lead to the
high regioselectivity of this transformation, and result in no
formation of the regioisomer of amide product F’.
À
In summary, we have demonstrated a direct C C func-
tionalization of aryl-substituted alkynes to amides under mild
reaction conditions. This method offers a novel application of
alkynes in organic synthesis. A nitrogenation process is
À
achieved by the highly selective Csp2 Csp bond cleavage of
substituted alkynes. The mechanistic insights into this novel
transformation may promote the discovery of other reactions
À
involving C C bond cleavage. Further studies into the
reaction mechanism and applications of this protocol are
ongoing in our group.
Received: April 21, 2013
Revised: May 28, 2013
Published online: June 26, 2013
À
Keywords: alkynes · amides · C C bond cleavage · gold ·
rearrangement
.
[8] For recent reviews on amide synthesis, see: a) E. Valeur, M.
Bradley, Chem. Soc. Rev. 2009, 38, 606; b) C. L. Allen, J. M. J.
Williams, Chem. Soc. Rev. 2011, 40, 3405; c) A. J. A. Watson,
J. M. J. Williams, Science 2010, 329, 635; d) K. Ekoue-Kovi, C.
Wolf, Chem. Eur. J. 2008, 14, 6302.
[1] M. B. Smith, J. March in Marchꢀs Advanced Organic Chemistry:
Reactions, Mechanisms, and Structure, Wiley, Hoboken, NJ, 2007.
À
[2] For some recent reviews of C H activation, see: a) D. A. Colby,
[9] For some selected recent examples on the reaction of azide
compounds, see: a) Y.-F. Wang, K. K. Toh, J.-Y. Lee, S. Chiba,
Angew. Chem. 2011, 123, 6049; Angew. Chem. Int. Ed. 2011, 50,
5927; b) Y.-F. Wang, K. K. Toh, E. P. J. Ng, S. Chiba, J. Am.
Chem. Soc. 2011, 133, 6411; c) B. J. Stokes, S. Liu, T. G. Driver, J.
Am. Chem. Soc. 2011, 133, 4702; d) Q. Nguyen, K. Sun, T. G.
Driver, J. Am. Chem. Soc. 2012, 134, 7262; e) J. Y. Kim, S. H.
Park, J. Ryu, S. H. Cho, S. H. Kim, S. Chang, J. Am. Chem. Soc.
2012, 134, 9110; f) J. Ryu, K. Shin, S. H. Park, J. Y. Kim, S.
Chang, Angew. Chem. 2012, 124, 10042; Angew. Chem. Int. Ed.
2012, 51, 9904; g) Z.-Y. Yan, Y. Xiao, L. Zhang, Angew. Chem.
2012, 124, 8752; Angew. Chem. Int. Ed. 2012, 51, 8624; h) B. Lu,
Y. Luo, L. Liu, L. Ye, Y. Wang, L. Zhang, Angew. Chem. 2011,
123, 8508; Angew. Chem. Int. Ed. 2011, 50, 8358; i) H. Lu, H.
Jiang, L. Wojtas, X. P. Zhang, Angew. Chem. 2010, 122, 10390;
Angew. Chem. Int. Ed. 2010, 49, 10192; j) W. Yao, L. Pan, Y.
Zhang, G. Wang, X. Wang, C. Ma, Angew. Chem. 2010, 122,
9396; Angew. Chem. Int. Ed. 2010, 49, 9210; k) K. Weidner, A.
Giroult, P. Panchaud, P. Renaud, J. Am. Chem. Soc. 2010, 132,
17511; l) I. Cano, E. ꢁlvarez, M. C. Nicasio, P. J. Perꢂz, J. Am.
Chem. Soc. 2011, 133, 191; m) S. Zhang, J. Zhao, W.-X. Zhang, Z.
Xi, Org. Lett. 2011, 13, 1626; n) J. Wang, J. Wang, Y. Zhu, P. Lu,
Y. Wang, Chem. Commun. 2011, 47, 3275; o) Z. Chen, C. Ye, L.
Gao, J. Wu, Chem. Commun. 2011, 47, 5623; p) C. Qin, W. Zhou,
F. Chen, Y. Ou, N. Jiao, Angew. Chem. 2011, 123, 12803; Angew.
Chem. Int. Ed. 2011, 50, 12595; q) T. Bach, B. Schlummer, K.
Harms, Chem. Commun. 2000, 287; r) T. Miura, T. Biyajima, T.
R. G. Bergman, J. A. Ellman, Chem. Rev. 2010, 110, 624; b) C.-L.
Sun, B.-J. Li, Z.-J. Shi, Chem. Rev. 2011, 111, 1293; c) T. W.
Lyons, M. S. Sanford, Chem. Rev. 2010, 110, 1147; d) C. S. Yeung,
V. M. Dong, Chem. Rev. 2011, 111, 1215; e) J. Le Bras, J. Muzart,
Chem. Rev. 2011, 111, 1170; f) L. Ackermann, Chem. Rev. 2011,
111, 1315; g) G. E. Dobereiner, R. H. Crabtree, Chem. Rev. 2010,
110, 681.
À
[3] For reviews on C C cleavage, see: a) R. H. Crabtree, Chem. Rev.
1985, 85, 245; b) B. Rybtchinski, D. Milstein, Angew. Chem.
1999, 111, 918; Angew. Chem. Int. Ed. 1999, 38, 870; c) C.-H. Jun,
Chem. Soc. Rev. 2004, 33, 610; d) M. Tobisu, N. Chatani, Chem.
Soc. Rev. 2008, 37, 300.
[4] For some reviews, see: a) P. Binger, U. Schuchardt, Chem. Ber.
1981, 114, 3313; b) A. Brandi, A. Goti, Chem. Rev. 1998, 98, 589;
c) I. Nakamura, Y. Yamamoto, Adv. Synth. Catal. 2002, 344, 111;
d) A. Brandi, S. Cicchi, F. M. Cordero, A. Goti, Chem. Rev. 2003,
103, 1213; e) W. R. Dolbier, Jr., M. A. Battiste, Chem. Rev. 2003,
103, 1071; f) A. Sekiguchi, V. Y. Lee, Chem. Rev. 2003, 103, 1429;
g) R. Walsh, Chem. Soc. Rev. 2005, 34, 714; h) Z.-B. Zhu, Y. Wei,
M. Shi, Chem. Soc. Rev. 2011, 40, 5534; i) B.-L. Lu, L. Dai, M.
Shi, Chem. Soc. Rev. 2012, 41, 3318.
[5] For selected recent examples, see: a) T. Ohmura, H. Taniguchi,
Y. Kondo, M. Suginome, J. Am. Chem. Soc. 2007, 129, 3518; b) T.
Matsuda, M. Shigeno, M. Murakami, J. Am. Chem. Soc. 2007,
129, 12086; c) C. Winter, N. Krause, Angew. Chem. 2009, 121,
2497; Angew. Chem. Int. Ed. 2009, 48, 2460; d) T. Seiser, O. A.
Roth, N. Cramer, Angew. Chem. 2009, 121, 6438; Angew. Chem.
Angew. Chem. Int. Ed. 2013, 52, 7850 –7854
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
7853

.
Angewandte
Communications
Fujii, M. Murakami, J. Am. Chem. Soc. 2012, 134, 194; s) C. Qin,
N. Jiao, J. Am. Chem. Soc. 2010, 132, 15893; t) C. Tang, N. Jiao, J.
Am. Chem. Soc. 2012, 134, 18924; u) T. Wang, W. Zhou, H. Yin,
J.-A. Ma, N. Jiao, Angew. Chem. 2012, 124, 10981; Angew. Chem.
Int. Ed. 2012, 51, 10823; v) D. Lubriks, I. Sokolovs, E. Suna, J.
Am. Chem. Soc. 2012, 134, 15436; w) T. Miura, Y. Funakoshi, M.
Morimoto, T. Biyajima, M. Murakami, J. Am. Chem. Soc. 2012,
134, 17440; x) M. Zibinsky, V. V. Fokin, Angew. Chem. 2013, 125,
1547; Angew. Chem. Int. Ed. 2013, 52, 1507; y) D. J. Gorin, N. R.
Davis, F. D. Toste, J. Am. Chem. Soc. 2005, 127, 11260; z) K.
Hiroya, S. Matsumoto, M. Ashikawa, K. Ogiwara, T. Sakamoto,
Org. Lett. 2006, 8, 5349.
Yamamoto, I. D. Gridnev, N. T. Patil, T. Jin, Chem. Commun.
2009, 5075; h) E. Jimꢂnez-NfflÇez, A. M. Echavarren, Chem.
Commun. 2007, 333; i) D. J. Gorin, B. D. Sherry, F. D. Toste,
Chem. Rev. 2008, 108, 3351.
[13] For some selected examples, see: a) H.-S. Yeom, J.-E. Lee, S.
Shin, Angew. Chem. 2008, 120, 7148; Angew. Chem. Int. Ed.
2008, 47, 7040; b) P. W. Davies, S. J.-C. Albrecht, Angew. Chem.
2009, 121, 8522; Angew. Chem. Int. Ed. 2009, 48, 8372; c) N. D.
Shapiro, F. D. Toste, J. Am. Chem. Soc. 2007, 129, 4160; d) A. M.
Jadhav, S. Bhunia, H.-Y. Liao, R.-S. Liu, J. Am. Chem. Soc. 2011,
133, 1769; e) Y. Wang, K. Ji, S. Lan, L. Zhang, Angew. Chem.
2012, 124, 1951; Angew. Chem. Int. Ed. 2012, 51, 1915; f) Y. Luo,
K. Ji, Y. Li, L. Zhang, J. Am. Chem. Soc. 2012, 134, 17412; g) D.
Qian, J. Zhang, Chem. Commun. 2012, 48, 7082; h) M. Zhang, J.
Zhang, Chem. Commun. 2012, 48, 6399; i) D. Wang, X. Ye, X.
Shi, Org. Lett. 2010, 12, 2088; j) D. Wang, R. Cai, S. Sharma, J.
Jirak, S. K. Thummanapelli, N. G. Akhmedov, H. Zhang, X. Liu,
J. L. Petersen, X. Shi, J. Am. Chem. Soc. 2012, 134, 9012.
[14] D. V. Partyka, J. B. Updegraff III, M. Zeller, A. D. Hunter, T. G.
Gray, Organometallics 2007, 26, 183.
[10] a) X. Jin, T. Oishi, K. Yamaguchi, N. Mizuno, Chem. Eur. J. 2011,
17, 1261; b) S. Gaillard, J. Bosson, R. S. Ramꢃn, P. Nun, A. M. Z.
Slawin, S. P. Nolan, Chem. Eur. J. 2010, 16, 13729; c) A. Leyva,
A. Leyva, J. Org. Chem. 2009, 74, 2067.
[11] a) K. F. Z. Schmidt, Angew. Chem. 1923, 36, 511; b) S. Lang, J. A.
Murphy, Chem. Soc. Rev. 2006, 35, 146.
[12] For reviews on gold-catalyzed activation of alkynes, see: a) S.
Ma, S. Yu, Z. Gu, Angew. Chem. 2006, 118, 206; Angew. Chem.
Int. Ed. 2006, 45, 200; b) A. S. K. Hashmi, Chem. Rev. 2007, 107,
3180; c) N. Marion, S. P. Nolan, Chem. Soc. Rev. 2008, 37, 1776;
d) E. Jimꢂnez-NfflÇez, A. M. Echavarren, Chem. Rev. 2008, 108,
3326; e) M. N. Hopkinson, A. D. Gee, V. Gouverneur, Chem.
Eur. J. 2011, 17, 8248; f) H. A. Wegner, M. Auzias, Angew. Chem.
2011, 123, 8386; Angew. Chem. Int. Ed. 2011, 50, 8236; g) Y.
[15] a) R. D. Bach, G. J. Wolber, J. Org. Chem. 1982, 47, 239; b) A.
Hassner, E. S. Ferdinandi, R. J. Isbister, J. Am. Chem. Soc. 1970,
92, 1672.
[16] M. Beller, J. Seayad, A. Tillack, H. Jiao, Angew. Chem. 2004, 116,
3448; Angew. Chem. Int. Ed. 2004, 43, 3368.
7854
www.angewandte.org
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2013, 52, 7850 –7854