High-Valent Pentamethylcyclopentadienylcobalt(III) or -iridium(III)-Catalyzed C H Annulation with Alkynes: Synthesis of Heterocyclic Quaternary Ammonium Salts

Article abstract of DOI:10.1002/adsc.201600194

Nine types of diversely fused heterocyclic quaternary ammonium salts were constructed through an oxidative C H annulation reaction. Both high-valent pentamethylcyclopentadienylcobalt(III) and pentamethylcyclopentadienyliridium(III) were found to be effective as catalyst for this reaction. Broad substrate scope and good functional group tolerance were observed. (Figure presented.) .

Full text of DOI:10.1002/adsc.201600194

UPDATES
DOI: 10.1002/adsc.201600194
High-Valent Pentamethylcyclopentadienylcobalt(III) or
À
-iridium(III)-Catalyzed C H Annulation with Alkynes: Synthesis
of Heterocyclic Quaternary Ammonium Salts
Ye-Xing Lao,a,b Shang-Shi Zhang,a Xu-Ge Liu,a Chun-Yong Jiang,a Jia-Qiang Wu,a
Qingjiang Li,a Zhi-Shu Huang,a and Honggen Wanga,*
a
School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, Peopleꢀs Republic of China
E-mail: wanghg3@mail.sysu.edu.cn
The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510230, Peopleꢀs Republic of China
b
Received: February 26, 2016; Revised: April 17, 2016; Published online: && &&, 0000
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201600194.
Abstract: Nine types of diversely fused heterocyclic
one of the major players with one exception of using
Ru(II)[8] and Cp*Ir(III)[9] (Figure 2). To realize eco-
nomically superior organic syntheses, there is a grow-
ing tendency of using earth-abundant and therefore
less expensive first-row transition metals (for instance,
iron, cobalt, nickel, and copper) in catalysis.[10] This is
also appealing considering that new reactivities might
be uncovered. Since the seminal works by Kanai,[11]
high-valent Cp*Co(III) complexes have recently
quaternary ammonium salts were constructed
À
through an oxidative C H annulation reaction.
Both high-valent pentamethylcyclopentadienylco-
balt(III) and pentamethylcyclopentadienyliridi-
ACHTUNGTRENNUNGum(III) were found to be effective as catalyst for
this reaction. Broad substrate scope and good func-
tional group tolerance were observed.
À
gained much attention as an effective catalyst for C
À
Keywords: C H activation; cobalt; heterocycles;
H activation reactions.[12] It is interesting to note that
compared to its congener Cp*Rh(III), Cp*Co(III)
iridium; oxidation
Heterocyclic quaternary ammonium salts are preva-
lent in functional molecules,[1] as represented by their
wide occurrence in numerous natural products, dis-
playing diverse bioactivities[2] (Figure 1). Convention-
al approaches for their synthesis suffer from the lack
of generality, the necessity for pre-functionalization of
the starting materials, and therefore the need of
lengthy synthetic operations.[3]
Recently, in line with the increasing concerns of
sustainable chemistry and green chemistry,[4] transi-
À
tion metal-catalyzed C H activation reactions have
matured as viable tools for atom- and step-economi-
cal organic syntheses.[5] In this regard, largely taking
the advantage of high reactivities of noble transition
À
metals, heterocycle syntheses through direct C H an-
nulations reaction are well developed.[6] This is ap-
pealing in the field of medicinal chemistry, wherein
the rapid and straightforward assembly of a small
molecule library with molecular complexity and diver-
sity is crucial for lead discovery and optimization.
Specifically, for the construction of heterocyclic qua-
Figure 1. Representative bioactive heterocyclic quaternary
ternary ammonium salts, high-valent Cp*Rh(III)[7] is ammonium salts in natural products.
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ed in high efficiency. Importantly, the reaction is also
À
amenable to alkenyl C H activation. Additionally, we
also explored the feasibility of using Cp*Ir(III)[15] as
catalyst for this transformation, with good results
being obtained. While preparing the manuscript,
Cheng reported a similar work using Cp*Co(III) as
catalyst under different reaction conditions.[16]
Initially, 2-phenylpyridine (1a) was reacted with
hex-3-yne (2a) using Cp*Co(CO)I2 as catalyst. De-
lightfully, after extensive screening, we were able to
obtain pyrido[2,1-a]isoquinolin-5-ium 3a in 39% iso-
lated yield under the reaction conditions of
Cp*Co(CO)I2 (10 mol%), AgBF4 (1.0 equiv.) and
Cu(OAc)2 (1.0 equiv.) in DCE at 608C for 24 h
(Table 1, entry 1). A simple elevation of the tempera-
ture to 1008C improved the yield to 86% (entries 2
and 3). Control experiments indicated that
Cp*Co(CO)I2 is essential for the reaction (entry 4).
The use of protic (MeOH) or polar (DMSO) solvents
Figure 2. Synthesis of heterocyclic quaternary ammonium
salts via direct C H annulation.
À
À
seems to favor redox-neutral C H addition reactions. led to diminished yields (entries 5 and 6). The sole
À
Relatively fewer oxidative C H functionalizations use of AgBF4 as additive gave only 4% yield
promoted by Cp*Co(III) are known in the literature. (entry 7).[16] Furthermore, the employment of differ-
We have been interested in exploring the synthesis ent silver and copper salts as co-oxidant gave inferior
and modification of biologically active small mole- results (entries 8–10).
[13]
À
cules by using the C H activation strategy. In our
With the optimized reaction conditions in hand, the
effort to discover new heterocyclic scaffolds targeting scope of this transformation was then extensively ex-
G-quadruplex DNA,[14] a simple and effective method plored. In general, diverse heterocyclic quaternary
for the construction of heterocyclic quaternary ammo- ammonium salts were constructed in satisfactory to
nium salts with structural diversity is highly demand- good yields (Scheme 1). 2-Phenylpyridines bearing
ed.
Herein,
different substituents regardless of the electronic
of properties underwent reaction smoothly (3b–g). The
we
disclose
our
realization
À
a Cp*Co(III)-catalyzed oxidative C H annulation of reaction took place at the less sterically hindered po-
diverse N-heterocycles/imines with alkynes. sition when meta-substituted substrates were used (3f
A
number of fused heterocyclic scaffolds were construct- and 3g). ortho-Substituents either on the aryl or pyri-
Table 1. Optimization of the reaction conditions.[a]
Entry
Solvent
Additive (equiv.)
Temperature [oC]
Yield[b]
1
2
3
4
5
6
7
8
9
10
DCE
DCE
DCE
DCE
MeOH
DMSO
DCE
DCE
DCE
DCE
AgBF4 (1.0), Cu(OAc)2 (1.0)
AgBF4 (1.0), Cu(OAc)2 (1.0)
AgBF4 (1.0), Cu(OAc)2 (1.0)
AgBF4 (1.0), Cu(OAc)2 (1.0)
AgBF4 (1.0), Cu(OAc)2 (1.0)
AgBF4 (1.0), Cu(OAc)2 (1.0)
AgBF4 (2.0)
AgOAc (10%), Cu(BF4)2·6H2O (2.0)
AgOAc(1.0), Cu(BF4)2·6H2O (1.0)
Cu(OAc)2 (1.0), Cu(BF4)2·6H2O (1.0)
60
80
39%
79%
86%
0[c]
2%
13%
4%
64%
34%
60%
100
100
100
100
100
100
100
100
[a]
Reaction conditions: 1a (0.3 mmol), 2a (0.9 mmol), Cp*Co(CO)I2 (0.03 mmol), additive, solvent (2.0 mL), 24 h.
Isolated yields.
Without catalyst.
[b]
[c]
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À
Scheme 1. Cp*Co(III)-catalyzed oxidative C H annulation of N-heterocycles with alkynes.
À
dinyl rings deteriorated the reactivity due to steric tion of alkenyl C H bond with alkynes was also ex-
reasons (3h–j). Importantly, it was found that other plored. The reactions of 2-vinylpyridine took place
N-heterocycles such as pyrimidine (6 and 7) and thia- smoothly, giving the corresponding quinolizin-5-ium
zole (8) could also be applied as the directing groups, salts in good efficiency [13a and 13b, Eq. (2)].
thus greatly enriching the structural diversity of the
Cp*Ir(III), the congener of Cp*Co(III) and
À
products. However, oxazole was found to be a less ef- Cp*Rh(III), was relatively less studied in C H annu-
fective directing group (9). The reaction was also lation reactions.[15] We were intrigued whether this
À
amendable to thienyl C H activation, giving the cor-
responding tri-heterocycle fused compounds (4 and
7). Benzo[h]quinoline was also suitable for this trans-
formation. In addition to dialkylalkynes, diarylalkynes
were compatible with the current reaction conditions
as well, giving the ammonium salts in good to excel-
lent yields, although low efficiency for the reaction of
dithienylacetylene was observed (3q–t). Two re-
gioisomers were obtained when unsymmetrical al-
kynes were used (3u and 3v).
To further extend the scope, imine 10 was reacted
with both dialkylalkyne and diarylalkyne [Eq. (1)].
Gratifyingly, under the identical reaction conditions,
1,2-isoquinolinium salts (11a and 11b) were formed in
satisfactory yields. In addition, the oxidative annula-
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À
Scheme 2. Cp*Ir(III)-catalyzed oxidative C H annulation of N-heterocycles with alkynes.
complex could also promote the same reaction. To nitrogen atom of the N-heterocycle is followed by
À
our delight, by simply switching the catalyst to a C H bond cleavage to form a cyclocobaltated spe-
[Cp*IrCl2]2, the oxidative annulation of diverse heter-
ocyclic substrates gave comparable results to the
Cp*Co(III)-catalyzed version (Scheme 2). Further-
more, imine and 2-vinylpyridine underwent the reac-
tion smoothly as well under the current catalytic
system. It is noteworthy that the reaction was also
amenable to an oxazole substrate, providing another
type of heterocyclic scaffold in reasonable yield (9).
To better understand the mechanism, several ex-
periments were conducted. A swift H/D scramble was
observed regardless of the presence or absence of
a coupling partner [Eq. (3)]. The incorporated proton
is supposed to come from the moisture of solvent.
This speculation is consistent with a more pronounced
H/D scramble when 10 equivalents of H2O were
added. Interestingly, inverse equilibrium isotope
effect values of 0.85 and 0.67 were measured for par-
allel and competition experiments, respectively [Eq.
À
(4)]. These results implicate rehybridization of the C
2
3
À
H bond from sp to sp in the C H bond activation
step.[17] It should be noted that these observations are
in sharp contrast to Chengꢀs observations.[16] In addi-
tion, the use of the radical scavenger TEMPO in the
reaction did not hamper the reactivity, which is indi-
cative that a radical mechanism is not involved in the
reaction [Eq. (5)].[18]
A plausible mechanism for the Cp*Co(III)-cata-
lyzed oxidative annulation reaction is outlined in
Scheme 3. Initially, the halogen abstraction and ligand
exchanges yield the reactive cationic catalyst
[Cp*Co(III)]2+ (A). Thereafter, coordination of the
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ture was then subjected to flash column chromatography on
silica gel using EtOAc/petroleum ether (1:1), and then
DCM/MeOH (20:1) as the eluent to give the products.
Acknowledgements
We are grateful for the support of this work by “1000-Youth
Talents Plan”, a Start-up Grant from Sun Yat-sen University
and National Natural Science Foundation of China
(81402794 and 21472250).
References
[1] a) T. Welton, Chem. Rev. 1999, 99, 2071–2084; b) K. R.
Seddon, Nat. Mater. 2003, 2, 363–365; c) R. P. Haug-
land, in: Handbook of Fluorescent Probes and Research
Chemicals, Molecular Probes Inc., Eugene, 2001; d) D.
Wu, L. Zhi, G. J. Bodwell, G. Cui, N. Tsao, K. Mꢂllen,
Angew. Chem. 2007, 119, 5513–5516; Angew. Chem.
Int. Ed. 2007, 46, 5417–5420.
[2] a) K. Bbadra, G. S. Kumar, Med Res. Rev. 2011, 31,
821–862; b) Z. Lv, H. Wei, E. Wang, Analyst 2009, 134,
1647–1651; c) V. Rosenkranz, M. Wink, Molecules
2008, 13, 2462–2473; d) Y. H. Choi, W. Y. Choi, S. H.
Hong, S. O. Kim, G. Y. Kim, W. H. Lee, Y. H. Yoo,
Chem-Biol. Interact. 2009, 179, 185–191; e) Z. Ding,
S. C. Tang, P. Weerasinghe, X. Yang, A. Pater, A. Lie-
pins, Biochem. Pharmacol. 2002, 63, 1415–1421; f) K.
Benner, H. Ihmels, S. Kçlsh, P. M. Pithan, Org. Biomol.
Chem. 2014, 12, 1725–1734; g) X. Cheng, D. Wang, L.
Jiang, D. Yang, Chem. Biodivers. 2008, 5, 1335–1344;
h) P. Dickens, R. Fitzgerald, P. M. Fischer, Semin.
Cancer Biol. 2010, 20, 10–18.
[3] a) R. B. Woodward, B. Witkop, J. Am. Chem. Soc.
1949, 71, 379–379; b) V. Boekelheide, J. P. Lodge Jr, J.
Am. Chem. Soc. 1951, 73, 3681–3684; c) V. Boekel-
heide, W. G. Gall, J. Am. Chem. Soc. 1954, 76, 1832–
1836; d) P. Crews, R. R. Kintne, H. C. Padgett, J. Org.
Chem. 1973, 38, 4391–4395; e) T. Fukutani, N. Umeda,
K. Hirano, T. Satoh, M. Miura, Chem. Commun. 2009,
5141–5143; f) P. C. Too, Y.-F. Wang, S. Chiba, Org. Lett.
2010, 12, 5688–5691.
[4] a) P. T. Anastas, J. C. Warner, in: Green Chemistry:
Theory and Practice, Oxford University Press, New
York, 1998; b) Y. Hayashi, Chem. Sci. 2016, 7, 866–880;
c) B. M. Trost, Science 1991, 254, 1471–1477; d) P. A.
Wender, M. P. Croatt, B. Witulski, Tetrahedron 2006,
62, 7505–7511; e) N. Z. Burns, P. S. Baran, R. W. Hoff-
mann, Angew. Chem. 2009, 121, 2896–2910; Angew.
Chem. Int. Ed. 2009, 48, 2854–2867.
Scheme 3. Proposed mechanism.
À
cies C. Based on our mechanistic studies, the C H ac-
tivation step might proceed via an electrophilic metal-
lation mechanism rather than the concerted metalla-
tion-deprotonation (CMD) or single electron transfer
mechanism,[18] and is reversible. Subsequently, a migra-
tory insertion of alkyne gives a seven-membered ring
intermediate D. Upon reductive elimination, the het-
erocyclic quaternary ammonium salt is formed. The
reduced Cp*Co(I) species is regenerated by the oxi-
dation of copper or silver salt.
In summary, we have successfully developed
À
a Cp*Co(III)-catalyzed C H annulation reaction with
alkynes towards the syntheses of heterocyclic quater-
nary ammonium salts. Diverse N-heterocycles and
imines were found to be efficient directing groups for
À
this transformation. In addition, alkenyl C H activa-
tion was also realized, greatly extending the reaction
scope. Importantly, we identified that the Cp*Ir(III)
complex was also effective for this transformation.
The evaluation of the biological activity of these
products toward G-quadruplex DNA is currently un-
derway in our laboratories. Given the simplicity of
this reaction and the importance of heterocyclic qua-
ternary ammonium salts as functional molecules, we
anticipate this reaction may find applications.
Experimental Section
[5] For selected reviews, see: a) R. Giri, B.-F. Shi, K. M.
Engle, N. Maugel, J.-Q. Yu, Chem. Soc. Rev. 2009, 38,
3242–3272; b) O. Daugulis, H.-Q. Do, D. Shabashov,
Acc. Chem. Res. 2009, 42, 1074–1086; c) T. W. Lyons,
M. S. Sanford, Chem. Rev. 2010, 110, 1147–1169;
d) D. A. Colby, R. G. Bergman, J. A. Ellman, Chem.
Rev. 2010, 110, 624–655; e) J. Wencel-Delord, T. Drçge,
F. Liu, F. Glorius, Chem. Soc. Rev. 2011, 40, 4740–4761;
f) B.-J. Li, Z.-J. Shi, Chem. Soc. Rev. 2012, 41, 5588–
General Procedure
To a 10-mL sealed tube were added the corresponding
substrate (0.3 mmol), alkyne (0.9 mmol, 3.0 equiv.),
Cp*Co(CO)I2
or
[Cp*IrCl2]2
(0.03 mmol),
AgBF4
(0.3 mmol), Cu(OAc)2 (0.3 mmol) and DCE (2.0 mL). The
resulting reaction mixture was allowed to stir at 1008C for
24 h. After cooling to room temperature, the reaction mix-
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ÞÞ
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5598; g) P. B. Arockiam, C. Bruneau, P. H. Dixneuf,
2015, 17, 5316–5319; l) T. Gensch, S. Vꢃsquez-Cꢄs-
pedes, D.-G. Yu, F. Glorius, Org. Lett. 2015, 17, 3714–
3717; m) Z.-Z. Zhang, B. Liu, C.-Y. Wang, B.-F. Shi,
Org. Lett. 2015, 17, 4094–4097; n) E. Ozkal, B. Cacher-
at, B. Morandi, ACS Catal. 2015, 5, 6458–6462; o) X.-K.
Guo, L.-B. Zhang, D. Wei, J.-L. Niu, Chem. Sci. 2015,
6, 7059–7071; p) J. Park, S. Chang, Angew. Chem. 2015,
127, 14309–14313; Angew. Chem. Int. Ed. 2015, 54,
14103–14107; q) Y. Liang, Y.-F. Liang, C. Tang, Y.
Yuan, N. Jiao, Chem. Eur. J. 2015, 21, 16395–16399.
[13] a) X.-G. Liu, S.-S. Zhang, C.-Y. Jiang, J.-Q. Wu, Q. Li,
H. Wang, Org. Lett. 2015, 17, 5404–5407; b) Y.-X. Lao,
J.-Q. Wu, Y. Chen, S.-S. Zhang, Q. Li, H. Wang, Org.
Chem. Front. 2015, 2, 1374–1378; c) X.-G. Liu, S.-S.
Zhang, J.-Q. Wu, Q. Li, H. Wang, Tetrahedron Lett.
2015, 56, 4093–4095; d) W. Cui, S. Chen, J.-Q. Wu, X.
Zhao, W. Hu, H. Wang, Org. Lett. 2014, 16, 4288–4291.
[14] a) Y. Ma, T.-M. Ou, J.-Q. Hou, Y.-J. Lu, J.-H. Tan, L.-
Q. Gu, Z.-S. Huang, Bioorg. Med. Chem. 2008, 16,
7582–7591; b) Y. Ma, T.-M. Ou, J.-H. Tan, J.-Q. Hou,
S.-L. Huang, L.-Q. Gu, Z.-S. Huang, Bioorg. Med.
Chem. Lett. 2009, 19, 3414–3417; c) Y. Ma, T.-M. Ou,
J.-H. Tan, J.-Q. Hou, S.-L. Huang, L.-Q. Gu, Z.-S.
Huang, Eur. J. Med. Chem. 2011, 46, 1906–1913; d) Y.-
X. Xiong, Z.-S. Huang, J.-H. Tan, Eur. J. Med. Chem.
2015, 97, 538–551.
Chem. Rev. 2012, 112, 5879–5918; h) L. Ackermann,
Acc. Chem. Res. 2014, 47, 281–295; i) G. Song, X. Li,
Acc. Chem. Res. 2015, 48, 1007–1020.
[6] X.-F. Wu, in: Transition Metal-Catalyzed Heterocycle
À
Synthesis via C H Activation, John Wiley & Sons,
2015.
[7] a) C.-Z. Luo, P. Gandeepan, Y.-C. Wu, C.-H. Tsai, C.-
H. Cheng, ACS Catal. 2015, 5, 4837–4841; b) N. Senthil-
kumar, P. Gandeepan, J. Jayakumar, C.-H. Cheng,
Chem. Commun. 2014, 50, 3106–3108; c) J. Jayakumar,
C.-H. Cheng, Chem. Eur. J. 2016, 22, 1800–1804; d) C.-
Z. Luo, J. Jayakumar, P. Gandeepan, Y.-C. Wu, C.-H.
Cheng, Org. Lett. 2015, 17, 924–927; e) G. Zhang, L.
Yang, Y. Wang, Y. Xie, H. Huang, J. Am. Chem. Soc.
2013, 135, 8850–8853; f) Z. Qi, S. Yu, X. Li, J. Org.
Chem. 2015, 80, 3471–3479.
[8] C.-Z. Luo, P. Gandeepan, C.-H. Cheng, Chem.
Commun. 2013, 49, 8528–8530.
[9] R. S. Phatake, P. Patel, C. V. Ramana, Org. Lett. 2016,
18, 292–295.
[10] For reviews, see: a) A. A. Kulkarni, O. Daugulis, Syn-
thesis 2009, 4087–4109; b) P. Kumar, J. Louie, Angew.
Chem. 2011, 123, 10956–10958; Angew. Chem. Int. Ed.
2011, 50, 10768–10769; c) J. J. Mousseau, A. B. Char-
ette, Acc. Chem. Res. 2013, 46, 412–424; d) C. Wang,
Synlett 2013, 24, 1606–1613; e) D. Tilly, G. Dayaker, P.
Bachu, Catal. Sci. Technol. 2014, 4, 2756–2777; f) L. Ac-
kermann, J. Org. Chem. 2014, 79, 8948–8954; g) K.
Gao, N. Yoshikai, Acc. Chem. Res. 2014, 47, 1208–1219;
h) F. Jia, Z. Li, Org. Chem. Front. 2014, 1, 194–214;
i) W. Liu, J. T. Groves, Acc. Chem. Res. 2015, 48, 1727–
1735; j) J. Miao, H. Ge, Eur. J. Org. Chem. 2015, 2015,
7859–7868.
[11] a) T. Yoshino, H. Ikemoto, S. Matsunaga, M. Kanai,
Angew. Chem. 2013, 125, 2263–2267; Angew. Chem. Int.
Ed. 2013, 52, 2207–2211; b) H. Ikamoto, T. Yoshino, K.
Sakata, S. Matsunaga, M. Kanai, J. Am. Chem. Soc.
2014, 136, 5424–5431; c) T. Andou, Y. Saga, H. Komai,
S. Matsunaga, M. Kanai, Angew. Chem. 2013, 125,
3295–3298; Angew. Chem. Int. Ed. 2013, 52, 3213–3216;
d) B. Sun, T. Yoshino, M. Kanai, S. Matsunaga, Angew.
Chem. 2015, 127, 13160–13164; Angew. Chem. Int. Ed.
2015, 54, 12968–12972.
[12] For a review, see: a) T. K. Hyster, Catal. Lett. 2015,
145, 458–467; for selected examples, see: b) T. M. Figg,
S. Park, J. Park, S. Chang, D. G. Musaev, Organometal-
lics 2014, 33, 4076–4085; c) J. Li, L. Ackermann,
Angew. Chem. 2015, 127, 3706–3709; Angew. Chem.
Int. Ed. 2015, 54, 3635–3638; d) D.-G. Yu, T. Gensch, F.
de Azambuja, S. Vꢃsquez-Cꢄspedes, F. Glorius, J. Am.
Chem. Soc. 2014, 136, 17722–17725; e) J. R. Hummel,
J. A. Ellman, J. Am. Chem. Soc. 2015, 137, 490–498;
f) P. Patel, S. Chang, ACS Catal. 2015, 5, 853–858;
g) A. B. Pawar, S. Chang, Org. Lett. 2015, 17, 660–663;
h) N. Yoshikai, ChemCatChem 2015, 7, 732–734; i) D.
Zhao, J. H. Kim, L. Stegemann, C. A. Strassert, F. Glo-
rius, Angew. Chem. 2015, 127, 4591–4594; Angew.
Chem. Int. Ed. 2015, 54, 4508–4511; j) J. R. Hummel,
J. A. Ellman, Org. Lett. 2015, 17, 2400–2403; k) N. Sau-
ermann, M. J. Gonzalez, L. Ackermann, Org. Lett.
À
[15] For selected Cp*Ir(III)-catalyzed C H functionaliza-
tions, see: a) K. Ueura, T. Satoh, M. Miura, J. Org.
Chem. 2007, 72, 5362–5367; b) M. Itoh, K. Hirano, T.
Satoh, Y. Shibata, K. Tanaka, M. Miura, J. Org. Chem.
2013, 78, 1365–1370; c) D. A. Frasco, C. P. Lilly, P. D.
Boyle, E. A. Ison, ACS Catal. 2013, 3, 2421–2429; d) J.
Ryu, J. Kwak, K. Shin, D. Lee, S. Chang, J. Am. Chem.
Soc. 2013, 135, 12861–12868; e) D. Lee, Y. Kim, S.
Chang, J. Org. Chem. 2013, 78, 11102–11109; f) J. Kim,
S. Chang, Angew. Chem. 2014, 126, 2235–2239; Angew.
Chem. Int. Ed. 2014, 53, 2203–2207; g) T. Kang, Y. Kim,
D. Lee, Z. Wang, S. Chang, J. Am. Chem. Soc. 2014,
136, 4141–4144; h) H. Hwang, J. Kim, J. Jeong, S.
Chang, J. Am. Chem. Soc. 2014, 136, 10770–10776; i) F.
Xie, Z. Qi, S. Yu, X. Li, J. Am. Chem. Soc. 2014, 136,
4780–4787; j) H. Wang, F. Xie, Z. Qi, X. Li, Org. Lett.
2015, 17, 920–923; k) Y. Wu, Y. Yang, B. Zhou, Y. Li, J.
Org. Chem. 2015, 80, 1946–1951; l) C. Pan, N. Jin, H.
Zhang, J. Han, C. Zhu, J. Org. Chem. 2014, 79, 9427–
9432; m) L. Li, W. W. Brennessel, W. D. Jones, J. Am.
Chem. Soc. 2008, 130, 12414–12419.
[16] S. Prakash, K. Muralirajan, C.-H. Cheng, Angew.
Chem. 2016, 128, 1876–1880; Angew. Chem. Int. Ed.
2016, 55, 1844–1848. Reaction conditions: substrate
(0.1 mmol),
alkyne
(0.15 mmol),
CoCp*(CO)I2
(10 mol%), AgOAc (10 mol%), AgBF4 (0.2 mmol),
NaHCO3 (0.12 mmol), DCE, 1308C, 24 h.
[17] a) J. A. Tunge, L. N. Foresee, Organometallics 2005, 24,
6440–6444; b) S.-L. Shi, S. L. Buchwald, Angew. Chem.
2015, 127, 1666–1670; Angew. Chem. Int. Ed. 2015, 54,
1646–1650; c) G. B. Boursalian, M.-Y. Ngai, K. N. Hojc-
zyk, T. Ritter, J. Am. Chem. Soc. 2013, 135, 13278–
13281.
[18] X.-K. Guo, L.-B. Zhang, D. Wei, J.-L. Niu, Chem. Sci.
2015, 6, 7059–7071.
Adv. Synth. Catal. 0000, 000, 0 – 0
6
ꢁ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÞÞ
These are not the final page numbers!

UPDATES
High-Valent Pentamethylcyclopentadienylcobalt(III) or
7
À
-iridium(III)-Catalyzed C H Annulation with Alkynes:
Synthesis of Heterocyclic Quaternary Ammonium Salts
Adv. Synth. Catal. 2016, 358, 1 – 7
Ye-Xing Lao, Shang-Shi Zhang, Xu-Ge Liu,
Chun-Yong Jiang, Jia-Qiang Wu, Qingjiang Li,
Zhi-Shu Huang, Honggen Wang*
Adv. Synth. Catal. 0000, 000, 0 – 0
7
ꢁ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÞÞ
These are not the final page numbers!