Electrochemical Oxidative Functionalization of Arylalkynes: Access to α,α-Dibromo Aryl Ketones

Article abstract of DOI:10.1002/adsc.202001105

A general and effective protocol to synthesize α,α-dibromo aryl ketones has been developed via an electrochemical oxidative method. The reaction proceeds smoothly at room temperature in an undivided cell without the addition of external oxidants. In the reaction process, LiBr acts as both bromine source and supporting electrolyte. This electrooxidation strategy has good substrate applicability and functional group compatibility. Moreover, the reaction could be scaled up efficiently in a continuous flow cell. The target product could undergo further functionalization for the synthesis of some useful heterocyclic compounds. (Figure presented.).

Full text of DOI:10.1002/adsc.202001105

Title: Electrochemical Oxidative Functionalization of Arylalkynes:
Access to α,α-Dibromoarylketones
Authors: Dan Wang, Zhaohua Wan, Heng Zhang, and Aiwen Lei
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Adv. Synth. Catal. 10.1002/adsc.202001105
Link to VoR: https://doi.org/10.1002/adsc.202001105

10.1002/adsc.202001105
Advanced Synthesis & Catalysis
COMMUNICATION
DOI: 10.1002/adsc.201((will be filled in by the editorial staff))
Electrochemical Oxidative Functionalization of Arylalkynes:
Access to α,α-Dibromo Aryl Ketones
Dan Wang,a‡ Zhaohua Wan,a‡ Heng Zhang,a* Aiwen Leia*
a
The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan
430072, P. R. of China.
Email: hengzhang@whu.edu.cn, aiwenlei@whu.edu.cn
‡ These authors contributed equally to this work.
Received: ((will be filled in by the editorial staff))
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201######.
Abstract. A general and effective protocol to synthesize
α,α-dibromo aryl ketones has been developed via an
electrochemical oxidative method. The reaction
proceeds smoothly at room temperature in an undivided
cell without the addition of external oxidants. In the
reaction process, LiBr acts as both bromine source and
supporting electrolyte. This electrooxidation strategy
has good substrate applicability and functional group
compatibility. Moreover, the reaction could be scaled up
efficiently in a continuous flow cell. The target product
could undergo further functionalization for the synthesis
Scheme 1. Examples of the synthesis of heterocyclic
of some useful heterocyclic compounds.
compounds from dibromo aryl ketones.
Keywords: electrochemistry; oxidation; external-
oxidant-free; arylalkynes; α,α-dibromo aryl ketones
α,α-Dihalo ketones are essential synthons in both
organic synthesis and the pharmaceutical industry,[1]
and could also be used to synthesize numerous
biologically active heterocyclic compounds (Scheme
1).[2] In the past few decades, tremendous efforts have
been devoted to developing facile and efficient
methods for synthesizing α,α-dihalo ketones from
alkynes.[3] The conversion of alkynes to the
corresponding dihalo ketones usually requires
corrosive halogen sources (Scheme 2a), such as N-
chlorosuccinimide (NCS),[4] N-bromosuccinimide
(NBS),[4] 1,3-dibromo-5,5-dimethylhydantoin,[5, 6] and
HX.[7] The following issues limit its potential
application: (1) the use of expensive/toxic halogen
sources; (2) the need for transition metal catalysts and
stoichiometric amount of exogenous oxidants; (3) the
harsh reaction conditions. Therefore, developing an
efficient and practical method for the synthesis of α,α-
dihalo ketones from alkynes is highly desirable.
Scheme 2. Synthesis of α,α-dihalo ketones based on
arylalkynes.
In the past decades, electrochemical reaction
protocols have shown the potential to be versatile and
sustainable methods for the synthesis of organic
compounds, and have attracted considerable
attention.[8]
Under
electrochemical
oxidative
conditions, substrates could be oxidized through single
electron transfer to construct various new bonds.[9-15]
In particular, electrochemical C-X formation is a
useful way to construct electrophiles, which can be
utilized for further synthetic manipulations.[15a,16]
Recently, Huang’s group reported the electrochemical
oxydihalogenation of arylalkynes using organic
halides as the halogen sources, including CHCl3,
1
This article is protected by copyright. All rights reserved.

10.1002/adsc.202001105
Advanced Synthesis & Catalysis
CH2Cl2, ClCH2CH2Cl, and CH2Br2 (Scheme 2b).[17]
selection of electrode material, carbon cloth as anode
and Pt plate as cathode showed best result (entries 1-
3). Both increasing or decreasing operating current
afforded 3a in lower yields (entries 4-5). The co-
solvent of H2O/CH3OH (9:1) was found to be more
efficient in this transformation (entries 6-9). The
bromide sources were also important for achieving a
good reaction efficiency. Lower yield of the desired
product were obtained when LiBr was replaced by
NaBr or KBr (entries 10-11). A significant decreased
reaction yield was obtained without the addition of p-
toluenesulfonic acid monohydrate, indicating that acid
was beneficial for this transformation. HCl and H2SO4
exhibited lower efficiency compared with p-
toluenesulfonic acid monohydrate (entries 12-14). In
the control experiment, no desired product would be
observed without electric current (entry 15).
Last year, our group reported
a
series of
electrochemical halogenation reactions using NaX/HX
as the halogen sources.[18] In our electro-synthetic
approach, to explore green halogenation methods is
one of our priority research topics. With this objective,
herein,
we
reported
the
electrochemical
oxydibromination of arylalkynes to synthesize α,α-
dibromoacetophenones with sustainable halogenating
agents under metal-free and external-oxidant-free
reaction conditions (Scheme 2c).
Initially, phenylacetylene (1a) and LiBr (2a) were
chosen as the model to optimize reaction conditions.
After considerable efforts, the electrochemical
oxydibromination of arylalkynes was successfully
achieved using LiBr as the halogen source in the
presence of p-toluenesulfonic acid monohydrate under
undivided electrolytic conditions (Table 1). The
desired product, 3a, could be obtained in 88% yield at
12 mA constant current for 4.5 h (entry 1). As for the
With the optimized reaction conditions in hand,
the scope of arylalkynes was then explored (as shown
in Table 2). Firstly, we tested the reactivity of various
substituted phenylacetylenes. Phenylacetylene bearing
methyl or tert-butyl group showed similar reactivity
Table 1. Optimization of the reaction conditions.[a]
Table 2. Substrate scope for the electrochemical oxidative
functionalization of arylalkynes.[a,b]
Entry Variation from standard conditions Yield(%)[b]
1
2
3
None
88
75
67
Pt plate(+)|Pt plate(-)
Carbon cloth(+)|Ni plate(-)
10 mA, 4.8 h
4
70
5
15 mA, 3.2 h
50
6
10 mL H2O
46
7
8
9
10
11
12
13
14
15
10 mL CH3OH
n.d.
n.d.
40
62
57
35
46
20
n.d.
CH3CN/CH3OH=9 mL/1 mL
H2O/CH3OH=5 mL/5 mL
NaBr instead of LiBr
KBr instead of LiBr
HCl instead of p-TsOHH2O
H2SO4 instead of p-TsOHH2O
no p-TsOHH2O
no electric current
[a]
Reaction conditions: 1a (0.5 mmol), LiBr (3.0 equiv.),
[a] Reaction conditions: 1a (0.5 mmol), LiBr (3.0 equiv.),
carbon cloth anode (15 mm × 15 mm × 0.36 mm), Pt plate
cathode (15 mm × 15 mm × 0.3 mm), constant current = 12
mA, p-TsOHH2O (3.0 equiv.), H2O (9 mL), CH3OH (1 mL),
room temperature, 4.5 h, undivided cell (4.03 F mol−1),
n.d.=not detected. [b] Isolated yields of 3.
carbon cloth anode (15 mm × 15 mm × 0.36 mm), Pt plate
cathode (15 mm × 15 mm × 0.3 mm), constant current = 12
mA, p-TsOHH2O (3.0 equiv.), H2O (9 mL), CH3OH (1 mL),
room temperature, 4.5 h, undivided cell (4.03 F mol−1),
n.d.=not detected. [b] Isolated yields of 3a.
2
This article is protected by copyright. All rights reserved.

10.1002/adsc.202001105
Advanced Synthesis & Catalysis
with phenylacetylene (3a-3c). Electron-donating
methoxy substituent at the para position was well
tolerated (3d). Phenylacetylenes bearing halogen
groups, such as fluorine, chlorine and bromine, were
able to deliver the desired products in good yields (3e-
3g). In addition, phenylacetylenes bearing electron-
withdrawing groups, such as aldehyde, ketone,
ester,etc. could also be suitable in this transformation
(3h-3l). Besides substituted phenylacetylenes, other
aromatic alkynes such as 2-naphthylacetylene and 3-
thiopheneacetylene could also gave the corresponding
product in good yields (3m and 3n). Moreover,
internal arylalkynes were found to be compatible with
this method to give the target products in good yields
(3o and 3p). Unfortunately, aliphatic alkynes were
incompatible in this transformation.
To further explore the practicality of our
approach, the reaction between 1a and 2a was
expanded to a 5 mmol scale. Considering the easy
scale-up feasibility, an electrochemical continuous
flow cell was employed and the desired product (3a)
could be obtained in 62% isolated yield (Scheme
3a).[19] According to the screening results in Table 1,
the co-solvent of methanol and water performed better
than pure water. Methanol is believed to facilitate the
dissolution of arylalkynes. Thus, a small amount of
methanol (100 L) was used to dissolve 1a and pure
water was used as the solvent. As a result, the yield has
been increased from 46% (entry 6, Table 1) to 65%
(Scheme 3b).
Scheme 4. Application in the synthesis of heterocyclic
compounds.
1-phenylethan-1-one (3a) was used as the starting
material to synthesize several useful heterocycles
(Scheme 4). Benzo[d]oxazol-2-yl(phenyl)methanone
could be prepared in 72% yield via a Et2NH/DMF
mediated cyclization between 2-aminophenol and 3a.
Benzo[d]thiazol-2-yl(phenyl)methanone could be
obtained in 40% yield when 2-aminophenol was
replaced with 2-aminothiophenol. Moreover, the
reaction between 1,2-diaminobenzene and 3a in the
Et2NH/DMF mediated reaction system could give 2-
phenylquinoxaline in 70% yield.
The electrochemical behavior of LiBr was
investigated by performing cyclic voltammetry (CV)
experiments as shown in Figure 1. An obvious
oxidation peak of LiBr was observed at 1.82 V (red
line). The mixture of LiBr and p-toluenesulfonic acid
monohydrate demonstrated an oxidation peak at 1.47
V (blue line), which demonstrated that the acid could
promote the oxidation of bromide. Moreover, a
catalytic current was observed when 1a was added,
which may result from the addition of bromine radical
to phenylacetylene (purple line).
Heterocyclic compounds are among the
important classes of organic chemicals in the
pharmaceutical and agrochemical industries.[20] To
expand the applicability of our protocol, 2,2-dibromo-
To gain more insight into the mechanism of this
electrochemical oxidative functionalization of
-1
blank
-0.8
LiBr
LiBr+p-TsOH
-0.6
LiBr+p-TsOH+phenylacetylene
-0.4
-0.2
0
0.2
0.4
0
0.5
1
1.5
2
Potential/V (vs Ag/AgCl)
Figure 1. Cyclic voltammetry of phenylacetylene, LiBr and
p-TsOHH2O in H2O/CH3OH.
Scheme 3. (a) Scale-up synthesis in an electrochemical
continuous flow cell. (b) Using H2O as solvent.
3
This article is protected by copyright. All rights reserved.

10.1002/adsc.202001105
Advanced Synthesis & Catalysis
anodic oxidation can produce intermediate I and II in
sequence. Subsequently, the nucleophilic attack of
H2O to intermediate II can generate the enol
intermediate III. In the meantime, the intermediate II
can react with bromide anion to produce the by-
product 3a’’. Since water is used as a solvent in the
reaction system, intermediate III should be formed
preferentially. The reaction between intermediate III
and bromine radical and the following single electron
oxidation and deprotonation can give the desired
product 3a. Meanwhile, intermediate III may also
undergo keto-enol tautomerization in the presence of
acid to afford by-product 3a’. Along with the anode
oxidation, concomitant cathodic reduction of protons
can generate H2 during the reaction process.
Scheme 5. Control experiments.
In conclusion, the electrochemical oxidative
functionalization of arylalkynes for the synthesis of
α,α-dibromoacetophenones has been achieved in an
undivided cell under mild conditions. No exogenous
oxidant is needed and easily available LiBr was used
as both the bromine source and the supporting
electrolyte during this transformation. Both terminal
and internal arylalkynes were compatible with this
protocol. In addition, the target product of this method
could be proceed further functionalization for the
synthesis of various heterocyclic compounds. The
study of electrooxidation functionalization of alkynes
is underway in our laboratory.
Scheme 6. Proposed mechanism.
arylalkynes, several control experiments were
performed (Scheme 5). As shown in Scheme 5a, no
desired product 3a could be detected under the
standard reaction conditions when acetophenone was
employed as the substrate, indicating that the reaction
does not go through an acetophenone intermediate.
Moreover, the target product 3a can be detected by
GC-MS when 2-bromo-1-phenylethan-1-one (3a')
was employed as the substrate (Scheme 5b).
Considering the keto-enol equilibrium, and 3a' could
be detected by GC-MS in the standard reaction, it is
speculated that 3a' and its enol form may be the
intermediates in this transformation. Furthermore, the
substrate scope exploration indicated that only
aromatic alkynes could be compatible with this
protocol, which indicated that the aryl group might
play a paramount role in stabilizing the reaction
intermediate.
Experimental Section
Electrochemical Synthesis of α,α- Dibromo Aryl
Ketones; General Procedure
The appropriate arylalkyne (0.5 mmol), LiBr (130.3
mg, 1.5 mmol), and p-toluenesulfonic acid monohydrate
(285.3 mg, 1.5 mmol) were combined and added to an oven-
dried undivided three-necked bottle (20 mL) equipped with
a stir bar. The bottle was equipped with carbon cloth
(1.5×1.5 cm2) and platinum plate (1.5×1.5 cm2) and was
then charged with nitrogen. Under the protection of N2, H2O
(9 mL) and CH3OH (1 mL) were injected respectively into
the tube via syringe. The reaction mixture was stirred and
electrolyzed at a constant current of 12 mA at room
temperature for 4.5 h. When the reaction was finished, the
reaction mixture was washed with water and extracted with
ethyl acetate (50 mL x 3). The organic layers were combined,
dried over Na2SO4, and concentrated. The pure product was
obtained by flash column chromatography on silica gel
using petroleum ether and ethyl acetate as the eluent.
Based on the above-mentioned results and
literature reports,[18, 21] a possible mechanism for this
electrochemical oxydibromination of arylalkynes is
proposed in Scheme 6. Initially, bromine radical is
yielded through the oxidation of bromide at the anode.
The addition of bromine radical and the following
4
This article is protected by copyright. All rights reserved.

10.1002/adsc.202001105
Advanced Synthesis & Catalysis
Acknowledgements
[7] T. Nobuta, S.-i. Hirashima, N. Tada, T. Miura, A.
Itoh, Tetrahedron Lett., 2010, 51, 4576-4578.
[8] a) J.-i. Yoshida, K. Kataoka, R. Horcajada, A.
Nagaki, Chem. Rev., 2008, 108, 2265-2299; b)
M. Yan, Y. Kawamata, P. S. Baran, Chem. Rev.,
2017, 117, 13230-13319; c) A. Wiebe, T.
Gieshoff, S. Moehle, E. Rodrigo, M. Zirbes, S. R.
Waldvogel, Angew. Chem. Int. Ed., 2018, 57,
5594-5619; d) S. R. Waldvogel, S. Lips, M. Selt,
B. Riehl, C. J. Kampf, Chem. Rev., 2018, 118,
6706-6765; e) S. Tang, Y. Liu, A. Lei, Chem,
2018, 4, 27-45; f) N. Sauermann, T. H. Meyer, Y.
Qiu, L. Ackermann, ACS Catal., 2018, 8, 7086-
7103; g) K. D. Moeller, Chem. Rev., 2018, 118,
4817-4833; h) M. D. Karkas, Chem. Soc. Rev.,
2018, 47, 5786-5865; i) A. Jutand, Chem. Rev.,
2008, 108, 2300-2347; j) Y. Jiang, K. Xu, C.
Zeng, Chem. Rev., 2018, 118, 4485-4540; k) Y.
Yuan, A. Lei, Acc. Chem. Res., 2019, 52, 3309-
3324; l) H. Wang, X. Gao, Z. Lv, T. Abdelilah,
A. Lei, Chem. Rev., 2019, 119, 6769-6787.
This work was supported by the National Natural Science
Foundation of China (22031008, 21520102003) and the Hubei
Province Natural Science Foundation of China (2017CFA010).
The Program of Introducing Talents of Discipline to Universities
of China (111 Program) is also appreciated. The numerical
calculations in this paper have been done on the supercomputing
system in the Supercomputing Center of Wuhan University.
Dedication
Dedicated to P.H. Dixneuf for his meaningful contribution to
organometallic chemistry and catalysis.
References
[1] a) M. L. Landry, N. Z. Burns, Acc. Chem. Res.,
2018
, 51, 1260–1271; b) J. Latham, E.
Brandenburger, S. A. Shepherd, B. R. K. Menon,
J. Micklefield, Chem. Rev., 2018, 118, 232–269;
c) F. H. Vaillancourt, E. Yeh, D. A. Vosburg, S.
Garneau-Tsodikova, C. T. Walsh, Chem. Rev.,
2006, 106, 3364–3378; d) I. Saikia, A. J. Borah,
P. Phukan, Chem. Rev., 2016, 116, 6837–7042.
[2] a) J. Jiang, H. Zou, Q. Dong, R. Wang, L. Lu, Y.
Zhu, W. He, J. Org. Chem., 2016, 81, 51–56; b)
O. Prakash, N. Sharma, K. Pannu, Synth.
Commun., 2007, 37, 1995-1999; c) M. Walter, Y.
von Coburg, K. Isensee, K. Sander, X. Ligneau,
J. C. Camelin, J. C. Schwartz, H. Stark, Bioorg.
Med. Chem. Lett., 2010, 20, 5879-5882; d) J.
Kim, D. Lee, C. Park, W. So, M. Jo, T. Ok, J.
Kwon, S. Kong, S. Jo, Y. Kim, J. Choi, H. C.
Kim, Y. Ko, I. Choi, Y. Park, J. Yoon, M. K. Ju,
J. Kim, S.-J. Han, T.-H. Kim, J. Cechetto, J. Nam,
P. Sommer, M. Liuzzi, J. Lee, Z. No, ACS Med.
Chem. Lett., 2012, 3, 678-682; e) J. Limanto, R.
A. Desmond, D. R. Gauthier, P. N. Devine, R. A.
Reamer, R. P. Volante, Org. Lett., 2003, 5, 2271-
2274; f) S. Srivastava, L. K. Bajpai, S. Batra, A.
P. Bhaduri, J. P. Maikhuri, G. Gupta, J. D. Dhar,
Bioorg. Med. Chem., 1999, 7, 2607-2613.
[9] a) L. Zhu, P. Xiong, Z.-Y. Mao, Y.-H. Wang, X.
Yan, X. Lu, H.-C. Xu, Angew. Chem. Int. Ed.,
2016, 55, 2226-2229; b) L. Zeng, H. Li, J. Hu, D.
Zhang, J. Hu, P. Peng, S. Wang, R. Shi, J. Peng,
C.-W. Pao, J.-L. Chen, J.-F. Lee, H. Zhang, Y.-
H. Chen, A. Lei, Nat. Catal., 2020, 3, 438-445;
c) Q.-L. Yang, X.-Y. Wang, J.-Y. Lu, L.-P.
Zhang, P. Fang, T.-S. Mei, J. Am. Chem. Soc.,
2018, 140, 11487-11494; d) K. Xu, Z. Zhang, P.
Qian, Z. Zha, Z. Wang, Chem. Commun., 2015
,
51, 11108-11111; e) Y.-C. Wu, S.-S. Jiang, R.-J.
Song, J.-H. Li, Chem. Commun., 2019, 55, 4371-
4374.
[10] a) Y. Wang, P. Qian, J.-H. Su, Y. Li, M. Bi, Z.
Zha, Z. Wang, Green Chem., 2017, 19, 4769-
4773; b) K.-J. Li, Y.-Y. Jiang, K. Xu, C.-C. Zeng,
B.-G. Sun, Green Chem., 2019, 21, 4412-4421;
c) J.-H. Wang, T. Lei, X.-L. Nan, H.-L. Wu, X.-
B. Li, B. Chen, C.-H. Tung, L. Z. Wu, Org. Lett.,
2019, 21, 5581-5585; d) S. Zhang, L. Li, H.
Wang, Q. Li, W. Liu, K. Xu, C. Zeng, Org. Lett.,
2018, 20, 252-255; e) D. Li, S. Li, C. Peng, L. Lu,
S. Wang, P. Wang, Y.-H. Chen, H. Cong, A. Lei,
Chem. Sci., 2019, 10, 2791-2795.
[3] a) C. F. Ye, J. M. Shreeve, J. Org. Chem., 2004
,
[11] Y. Liu, L. Xue, B. Shi, F. Bu, D. Wang, L. Lu, R.
Shi, A. Lei, Chem. Commun., 2019, 55, 14922-
14925.
69, 8561-8563; b) S. A. Rather, A. Kumar, Q. N.
Ahmed, Chem. Commun., 2019, 55, 4511-4514;
c) P. Pandit, K. S. Gayen, S. Khamarui, N.
[12] a) L. Li, Q. Yang, Z. Jia, S. Luo, Synthesis, 2018
,
Chatterjee, D. K. Maiti, Chem. Commun., 2011
,
50, 2924-2929; b) H. Wang, K. Liang, W. Xiong,
S. Samanta, W. Li, A. Lei, Sci. Adv., 2020, 6,
eaaz0590; c) L. Zhang, Z. Zhang, J. Hong, J. Yu,
J. Zhang, F. Mo, J. Org. Chem., 2018, 83, 3200-
3207.
47, 6933-6935; d) Y. Li, T. Mou, L. Lu, X. Jiang,
Chem. Commun., 2019, 55, 14299-14302; e) J.
M. D'Oyley, A. E. Aliev, T. D. Sheppard, Angew.
Chem. Int. Ed., 2014, 53, 10747-10750; f) E.
Cho, A. Jayaraman, J. Lee, K. C. Ko, S. Lee, Adv.
Synth. Catal., 2019, 361, 1846-1858.
[13] a) P. Feng, G. Ma, X. Chen, X. Wu, L. Lin, P.
Liu, T. Chen, Angew. Chem. Int. Ed., 2019, 58,
8400-8404; b) N. Fu, G. Sauer, A. Saha, A. Loo,
S. Lin, Science, 2017, 357, 575-579; c) X. Gao,
P. Wang, L. Zeng, S. Tang, A. Lei, J. Am. Chem.
Soc., 2018, 140, 4195-4199; d) K. Liu, S. Tang,
T. Wu, S. Wang, M. Zou, H. Cong, A. Lei, Nat.
Commun., 2019, 10, 639; e) N. Sauermann, R.
[4] L. Finck, J. Brats, B. Pavuluri, F. Gallou, S.
Handa, J. Org. Chem., 2018, 83, 7366-7372.
[5] P. Wu, S. Xu, H. Xu, H. Hu, W. Zhang,
Tetrahedron Lett., 2017, 58, 618-621.
[6] C. Wu, X. Xin, Z.-M. Fu, L.-Y. Xie, K.-J. Liu, Z.
Wang, W. Li, Z.-H. Yuan, W.-M. He, Green
Chem., 2017, 19, 1983-1989.
5
This article is protected by copyright. All rights reserved.

10.1002/adsc.202001105
Advanced Synthesis & Catalysis
Mei, L. Ackermann, Angew. Chem. Int. Ed.,
[16] Z. Zhou, Y. Yuan, Y. Cao, J. Qiao, A. Yao, J.
Zhao, W. Zuo, W. Chen, A. Lei, Chin. J. Chem.,
2019, 37, 611-615.
[17] X. Meng, Y. Zhang, J. Luo, F. Wang, X. Cao, S.
Huang, Org. Lett., 2020, 22, 1169-1174.
[18] Y. Yuan, A. Yao, Y. Zheng, M. Gao, Z. Zhou, J.
Qiao, J. Hu, B. Ye, J. Zhao, H. Wen, A. Lei,
iScience, 2019, 12, 293-303.
[19] D. Wang, P. Wang, S. Wang, Y.-H. Chen, H.
Zhang, A. Lei, Nat. Commun., 2019, 10, 2796.
[20] K. C. Majumdar, S. K. C Heterocycles in Natural
Product Synthesis; Wiley-VCH: Weinheim,
2018, 57, 5090-5094; f) S. Tang, S. Wang, Y.
Liu, H. Cong, A. Lei, Angew. Chem. Int. Ed.,
2018, 57, 4737-4741; g) Z. Wan, D. Wang, Z.
Yang, H. Zhang, S. Wang, A. Lei, Green Chem.,
2020, 22, 3742-3747.
[14] a) P. Wang, S. Tang, P. Huang, A. Lei, Angew.
Chem. Int. Ed., 2017, 56, 3009-3013; b) Y.-C.
Wu, S.-S. Jiang, S.-Z. Luo, R.-J. Song, J.-H. Li,
Chem. Commun., 2019, 55, 8995-8998.
[15] a) X. Sun, H.-X. Ma, T.-S. Mei, P. Fang, Y. Hu,
Org. Lett., 2019, 21, 3167-3171; b) N. Fu, G. S.
Sauer, S. Lin, J. Am. Chem. Soc., 2017, 139,
15548-15553; c) C. Chen, J.-C. Kang, C. Mao, J.-
W. Dong, Y.-Y. Xie, T.-M. Ding, Y.-Q. Tu, Z.-
M. Chen, S.-Y. Zhang, Green Chem., 2019, 21,
4014-4019.
Germany, 2011
.
[21] a) Z. Zheng, B. Han, P. Cheng, J. Niu, A. Wang,
Tetrahedron, 2014, 70, 9814; b) M. V. Adhikari,
S. D. Samant, Ultrason. Sonochem., 2002, 9,
107-111.
6
This article is protected by copyright. All rights reserved.

10.1002/adsc.202001105
Advanced Synthesis & Catalysis
COMMUNICATION
Electrochemical Oxidative Functionalization of
Arylalkynes: Access to α,α-Dibromo Aryl Ketones
Adv. Synth. Catal. Year, Volume, Page – Page
Dan Wang,‡ Zhaohua Wan,‡ Heng Zhang,* Aiwen
Lei*
7
This article is protected by copyright. All rights reserved.