Synthesis of Diverse Aryliodine(III) Reagents by Anodic Oxidation?

Article abstract of DOI:10.1002/cjoc.202000501

An anodic oxidation enabled synthesis of hypervalent iodine(III) reagents from aryl iodides is demonstrated. Under mild electrochemical conditions, a range of aryliodine(III) reagents including iodosylarenes, (difunctionaliodo)arenes, benziodoxoles and diaryliodonium salts can be efficiently synthesized and derivatized in good to excellent yields with high selectivity. As only electrons serve as the oxidation reagents, this method offers a more straightforward and sustainable manner avoiding the use of expensive or hazardous chemical oxidants.

Full text of DOI:10.1002/cjoc.202000501

Chinese Journal
of Chemistry
CJC
中 国 化 学 - An International Journal
Accepted Article
Title: Synthesis of Diverse Aryliodine(III) Reagents by Anodic Oxidation
Authors: Bing Zu, Jie Ke, Yonghong Guo, and Chuan He*
This manuscript has been accepted and appears as an Accepted Article online.
This work may now be cited as: Chin. J. Chem. 2020, 38, 10.1002/cjoc.202000501.
The final Version of Record (VoR) of it with formal page numbers will soon be
published online in Early View: http://dx.doi.org/10.1002/cjoc.202000501.
ISSN 1001-604X • CN 31-1547/O6
mc.manuscriptcentral.com/cjoc
www.cjc.wiley-vch.de

Chinese Journal
of Chemistry
Electrochemistry, Anodic oxidation, Hypervalent iodines, Aryliodine(III)
reagents, Aryl iodide catalysis
Report
CJC
中
国 化 学 - An International Journal
Synthesis of Diverse Aryliodine(III) Reagents by Anodic Oxidation
Bing Zu,‡,a,b Jie Ke,‡,b Yonghong Guo,b and Chuan He*,b
aSchool of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150080, China
bShenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and
Technology, Shenzhen, Guangdong 518055, China
Cite this paper: Chin. J. Chem. 2019, 37, XXX—XXX. DOI: 10.1002/cjoc.201900XXX
Summary of main observation and conclusion An anodic oxidation enabled synthesis of hypervalent iodine(III) reagents from aryl iodides is
demonstrated. Under mild electrochemical conditions, a range of aryliodine(III) reagents including iodosylarenes, (difunctionaliodo)arenes, benziodoxoles
and diaryliodonium salts can be efficiently synthesized and derivatized in good to excellent yields with high selectivity. As only electrons serve as the
oxidation reagents, this method offers a more straightforward and sustainable manner avoiding the use of expensive or hazardous chemical oxidants.
processes.[8] With the development of equipment and technology
in electrochemistry, the use of electricity in organic synthesis is
Background and Originality Content
Hypervalent iodine reagents have taken a privileged position
currently experiencing a renaissance. A few studies have shown
in modern organic synthesis due to their electrophilicity, valuable
that anodic oxidation of aryl iodides provide an effective approach
oxidizing properties and excellent leaving group ability, along with
for the generation of unstable hypervalent iodine reagents
their nontoxic, environment-friendly nature.[1] These reagents,
((difluoroiodo)arenes or (dialkoxyiodo)arenes), which are mainly
especially
aryliodine(III)
compounds,
find
tremendous
used in situ as redox mediators for the further transformation of
organic substrates.[9] For the electro-generation of stable
aryliodine(III) reagents, the preliminary work is mainly focus on
the electrochemical synthesis of diaryliodonium salts (Scheme
1a).[10] With the continued interest in electrosynthesis and
hypervalent iodine chemistry, we questioned whether one simple
and general anodic oxidation setting could be established for the
direct synthesis of various types of hypervalent iodine(III) reagents.
Herein we present a general electrochemical method for the
synthesis of diverse aryliodine(III) reagents by anodic oxidation.
Under mild conditions, a range of aryliodine(III) reagents including
iodosylarenes, (difunctionaliodo)arenes, benziodoxoles and
diaryliodonium salts can be efficiently synthesized and derivatized
in good to excellent yields with high selectivity (Scheme 1b).
applications in diverse chemical settings, including oxygenation
and oxidative functionalization of various organic substrates,[2]
functionalization of C−H bonds,[3] as group-transfer reagents in
numerous bond-forming reactions,[4] and as carbon and
heteroatom radical precursors or acceptors.[5] Therefore,
development of facile, sustainable methods for the efficient
preparation and derivatization of aryliodine(III) reagents is highly
demanded.
Typically, synthesis of aryliodine(III) reagents from aryl iodide
requires the use of stoichiometric amount or an excess of
expensive or hazardous chemical oxidants, such as peroxides
(m-chloroperbenzoic acid, hydrogen peroxide etc.), NaBO3, NaIO4,
Oxone or Selectfluor, which makes the process cumbersome with
a significant environmental footprint.[1a,1b,1i] Recently, utilization of
O2 as a terminal oxidant, Miyamoto, Uchiyama et al. and Powers
et al. respectively developed an elegant aerobic oxidation of
iodine(I) precursors producing hypervalent iodine reagents via
aldehyde autoxidation intermediates without or with metal
catalyst.[6] Since oxidation of aryl iodides is necessary for the
generation of aryliodine(III) reagents, directly using electrons to
perform oxidative transformation is undoubtably more
straightforward. In fact, organic electrochemistry is known for a
long time, offering an efficient and mild alternative to
conventional chemical approaches for redox transformations.[7] As
only electrons serve as reagents, it provides a cleaner manner
avoiding the generation of chemical waste. Moreover, organic
electrochemistry also allows for precise, external control of the
electroorganic transformation by regulating the applied potential,
which gives rise to inherently higher reaction selectivity, better
functional group tolerance, milder reaction conditions, and safer
This article has been accepted for publication and undergone full peer review but has not been
through the copyediting, typesetting, pagination and proofreading process which may lead to
differences between this version and the Version of Record. Please cite this article as doi:
10.1002/cjoc.202000501
This article is protected by copyright. All rights reserved.

First author et al.
Report
Scheme 1 Anodic oxidation of aryl iodides to aryliodine(III) reagents.
(difunctionaliodo)arenes 2a’ could be obtained in 91% NMR yield
(entry 10).
work:
electrochemical
of iodine(III)
generation
species
previous
(a)
Table 1 Effects of reaction parameters.
F
R
FO
=
I
15 mA,
C(+) | Pt(-),
H O
I
I
CF3CH2O
or
F
I
I
equiv)
(5.0
2
ORF
I
R
R
O
OCH2CF3
rt, 1.5 h
cell
LiClO4 TFE,
,
I
undivided
(difluoroiodo)arenes
(dialkoxyiodo)arenes
1a
2a
2a'
R
and used
as
X
unstable
in situ
redox mediators
R'
Entry
Variation from standard conditions
none
nBu4NBF4 instead of LiClO4
Pt (+) | Pt (-) instead of C (+) | Pt (-)
C (+) | C (-) instead of C (+) | Pt (-)
CH3CN instead of TFE
2a Yielda /%
I
1
2
80
57
R
salts
diaryliodonium
3
66
work:
this
anodic oxidation toward diverse
aryliodine(III)
general
reagents
(b)
4
12
5
25
I
I
(III)
2 H+
6
MeOH instead of TFE
trace
70
+
+
H2
R
R
7
10 mA instead of 15 mA, 2.3 h
20 mA instead of 15 mA, 1.1 h
without current
OTf
L
O
I
L
8
71
I
I
I
O
O
9
10b
n.d.
R
L
R
R
R'
without H2O
91 of 2a’
benziodoxoles
Standard conditions: graphite anode, Pt plate cathode, constant current =
15 mA (j = 10 mA/cm2), 1a (0.2 mmol), H2O (1.0 mmol), LiClO4 (0.4 mmol),
TFE (3.0 mL), room temperature, 1.5 h, undivided cell (2.1 F/mol).
aIsolated yields. n.d. = not detected; bNMR yield of 2a’, see Supporting
Information for details.
iodosylarenes
(difunctionaliodo)
arenes
diaryliodonium
salts
efficiency
high
selectivity
high
mild conditions
general
applicability
Results and Discussion
With the optimized reaction conditions in hand for the
preparation of iodosylarenes, we applied various aryl iodides to
this electrochemical method (Table 2). Since iodosylarenes are
widely used as effective oxidizing reagents in synthetic chemistry,
substitution of the aromatic ring would offer a synthetic handle to
tune both their oxidation potential and aggregation state.[11] We
found that aryl iodides with substituents at the para, meta and
ortho position of the aromatic ring all provided the desired
products in good yields (2b-2k). Electron-withdrawing substituted
groups on the aromatic ring were well tolerated under the
electrochemical conditions, such as fluoro, chloro, bromo, ester,
cyano and trifluoromethyl groups (2d-2k). Aryl iodides displaying
alkyl substituents, such as methyl and tert-butyl group could also
be introduced giving the corresponding oxidation product (2b, 2c).
Moreover, simply replacing H2O into AcOH, KCl, or changing the
solvent into 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) in the
absence of H2O, three classic (difunctionaliodo)arenes,
PhI(OAc)2,PhICl2 and PhI[OCH(CF3)2]2 (2l-2n) could be obtained in
good to excellent yields with high selectivity, which are common
hypervalent iodine(III) reagents in organic synthesis. It is worth
mentioning that the gram scale synthesis of 2l could also proceed
smoothly in 84% yield. Unfortunately, electron-donating groups,
such as methoxy, amino substituents, on the aromatic ring are not
suitable in this process. Efforts to access dinuclear iodine(III)
reagents from 2,2'-diiodo-1,1'-biaryl compounds under the
current conditions are not successful. In addition, besides simple
electron-transfer in oxidation reactions, the use of benziodoxoles
as hetero- and carbon- atom transfer reagents offers a powerful
We initiated our investigation of anodic oxidation of aryl
iodides for the generation of iodosylarenes, which are a broadly
important class of hypervalent iodine(III) reagents to be used in
many oxidation reactions.[1a,1b,1i] Normally, these iodosyl
compounds are prepared by hydrolysis of (diacetoxyiodo)arenes
or (dichloroiodo)arenes with aqueous NaOH. Therefore, we
commenced our study of the anodic oxidation of iodobenzene 1a
in the presence of H2O. After a careful examination of the anodic
oxidation conditions, we found that the desired aryliodine(III)
compound iodosylbenzene 2a can be obtained in 80% yield under
15 mA constant current (j = 10 mA/cm2) in 1.5 h by utilizing LiClO4
as the electrolyte, 2,2,2-trifluoroethanol (TFE) as the solvent, in
the presence of 5.0 equivalent H2O (Table 1, entry 1). A lower
yield was observed when nBu4NBF4 replaced LiClO4 as the
electrolyte (entry 2). Either using platinum plate to replace the
graphite anode or using graphite to replace the platinum plate
cathode led to the decrease of reaction yields (entries 3 and 4).
The solvent had a major influence on this anodic oxidation
reaction. When the solvent was changed to CH3CN, the yield of 2a
reduced sharply, while methanol was not suitable for this
transformation at all (entries 5 and 6). When keeping electric
quantity constant, both a decrease and an increase in current
from the standardized value of 15 mA afforded slightly lower
yields (entries 7 and 8). When the reaction was carried out in air
without electricity, no oxidation product was obtained (entry 9). It
is noteworthy that, in the absence of H2O, unstable
www.cjc.wiley-vch.de
© 2019 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2019, 37, XXX－XXX
This article is protected by copyright. All rights reserved.

Running title
Chin. J. Chem.
method in numerous bond-forming reactions.[4b, 12] Under slightly
modified electrochemical conditions, we found that 2-iodobenzoic
acid could successfully convert into benziodoxole reagents in high
yields, containing OCH2CF3 and OH groups (2o, 2p). The
electro-generation of these three types of aryliodine(III) species is
proposed to proceed via a two electron anodic oxidation of
iodoarene 1. The reduction of protons represents the cathodic
half-reaction, rendering H2 as the by-product (see Scheme S1 in
Supporting Information).
Diaryliodonium salts are usually air- and moisture-stable
compounds, which are widely employed as exceptional aryl-group
13]
transfer reagents in cross-coupling reactions.[4a,
A few
preliminary studies have shown that these compounds can be
produced under electrochemical conditions.[10] After some further
investigations, we found that utilizing trifluoromethanesulfonic
acid (TfOH) as both the electrolyte and counteranion, CH3CN and
TFE as the mixed solvent, a variety of diaryliodonium salts could
be obtained in good to excellent yields under 5 mA constant
current in 2 h (Table 3). Both cyclic (4a-4c) and acyclic (4d-4h)
iodonium salts could be produced smoothly by this
electrosynthesis method. Halogen substituted groups F, Cl, and Br
on the aromatic ring were well tolerated in the anodic oxidation
(4b, 4f-4h).
Table 2 Anodic oxidation for the synthesis of diverse aryliodine(III)
reagents from aryl iodidesa.
=
I
15 mA,
L
C(+) | Pt(-),
I
I
H2
O
equiv)
(5.0
L
R
R
TFE, rt, 1.5 h
cell
LiClO4
,
Table 3 Anodic oxidation for the synthesis of diaryliodonium saltsa.
undivided
1
2
OTf
=
mA
5
I
C(+) | Pt(-),
TfOH
(5.0
I
I
equiv)
/2.0
I
I
I
O
O
O
O
O
O
'
'
R
mL)
CH CN/TFE
R
R
(1.0
R
3
Me
tBu
F
rt, 2 h
4
3
I
cell
undivided
2b
2c
2d
2g
80%
75%
81%
,
,
,
I
I
I
OTf
OTf
OTf
I
I
Cl
Br
MeO2C
F
2e
,
2f
78%
67%
75%
,
,
Me Me
4c
CN
4a
4b
67%
,
90%
52%
,
,
I
I
I
I
MeO2C
O
O
O
O
NC
OTf
I
OTf
I
OTf
I
Me
Me
2h
2i
2j
77%
76%
86%
,
,
,
AcO
Cl
Me
Me Me
Me
Me
X
Me
Me
I
I
OAc
Cl
81%b
73%b
60%
=
4d
4e
,
4f
X
,
,
F,
F
3C
=
4g
X
Cl, 69%
Br, 73%
,
,
94%,b
81%d
2m
,
2k
,
2l
77%
,
=
4h
X
g)c
84%
(1.36
aStandard conditions: graphite anode, Pt plate cathode, constant current =
5 mA (j = 3.3 mA/cm2), aryl iodide (0.2 mmol), arene (0.3 mmol, for
intermolecular reaction), TfOH (1.0 mmol), CH3CN (1.0 mL), TFE (2.0 mL),
room temperature, 2 h, undivided cell (0.93 F/mol), isolated yields. bTFE
(3.0mL), without CH3CN.
I
I
OH
O
OCH2CF3
O
O
C)2HCO
(F3
I
O
OCH(CF3 2
)
86%e
86%
97%g
2p
,
f
2n
2o,
,
Moreover, to demonstrate the efficacy of this electrochemical
process for the anodic oxidation synthesis of diverse hypervalent
iodine(III) reagents, we showed that simple iodobenzene can be
efficiently transferred into phenyliodine diacetate (PIDA) under
mild electrochemical conditions (Scheme 2). Further treatment
with some common reagents led to the facile ligand exchange,
derivatizing a variety of useful hypervalent iodine(III) reagents in
good to excellent yields with high selectivity, including
[hydroxy(phosphoryloxy)iodo] benzene (5),[14] Koser’s reagent
(6),[15] amidoiodane (7),[16] iodonium imide (8),[17] alkynyliodonium
salt (9),[18] aryliodonium ylide (10),[19] and Weiss’ reagent (11),[20]
which all find numerous applications in various bond-forming
aStandard conditions: graphite anode, Pt plate cathode, constant current =
15 mA (j = 10 mA/cm2), 1 (0.2 mmol), H2O (1.0 mmol), LiClO4 (0.4 mmol),
TFE (3.0 mL), room temperature, 1.5 h, undivided cell (2.1 F/mol), isolated
yields. b1a (1.0 mmol), AcOH (5.0 mmol) instead of H2O, LiClO4 (0.2 mmol),
c
TFE (6.0 mL), 7.5 h. gram scale synthesis, see Supporting Information for
e
details. dKCl (0.6 mmol) instead of water. 1a (0.6 mmol), without H2O,
nBu4NBF4 (0.6 mmol) instead of LiClO4, HFIP (3.0 mL) instead of TFE, 3.0 h,
NMR yield. fwithout H2O. gCH3CN (3.0 mL) instead of TFE.
We next explored the capability of this electrochemical setting
for the anodic oxidative preparation of diaryliodonium salts.
Chin. J. Chem. 2019, 37, XXX－XXX
© 2019 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
This article is protected by copyright. All rights reserved.

First author et al.
Report
reactions. Furthermore,
a
range of important benziodoxole
iodobenzene 1a as the catalyst precursor enabled by anodic
oxidation (Scheme 4). The difunctionalization of alkene 16 and
tosyloxylation of 18 proceed smoothly under mild aryl iodide
catalyzed electrochemical conditions.
reagents containing useful OMe (12), OAc (13), CN (14), and
acetylene (15) groups could be obtained in good to high yields via
the ligand exchange from crude hydroxy benziodoxolone 2p
(Scheme 3).
Scheme 4 Anodic oxidation enabled aryl iodide catalyzed reactions.
Scheme 2 Derivatization of PIDA in the anodic oxidation process.
OCH2CF3
=
Pt
Pt
I
15 mA,
(+) |
1a
(-),
HO
HO
AcO
mol%)
(20
I
I
I
OH
O
(1)
NTs2
OTs
OP(O)Ph2
n
Bu4NBF4 TFE, rt, 1 h
,
O
O
16
17
, 66%
5
6
7
65%
80%
92%
,
,
,
=
I
(-),
TsOH•H2O
Pt
Pt
5 mA,
(+) |
1a
Ts2NH
O
O
HOP(O)Ph2
mol%)
(20
OTs
(2)
Me
CO2
TsOH•H O
equiv)
(5.0
2
CO2
Me
n
Bu4NBF4 TFE, rt, 2 h
,
AcO
I
I
I
NTs
18
19
,
60%
OAc
HOAc
TsNH2
crude
2l
8
71%
,
Conclusions
O
In summary, we have developed a general electrochemical
method for the efficient and sustainable synthesis of diverse
aryliodine(III) reagents by anodic oxidation. This process works for
a variety of aryl iodide to generate a range of aryliodine(III)
reagents including iodosylarenes, (difunctionaliodo)arenes,
benziodoxoles and diaryliodonium salts in good to excellent yields
with high selectivity under mild electrochemical conditions. All
the aryliodine(III) products were easily produced with one simple
anodic oxidation setting, and purified by simple filtering, washing,
or extraction. We also demonstrate that simple aryl iodide can
be used as catalyst precursor or catalytic mediator under anodic
oxidation, which provides a more efficient and sustainable tactic
for the rapid transformation of organic molecules.
N2
CO2Me
CO2Me
Ph
O
BF4
I
O
OCOCF3
Ph
I
Me
CO2
I
O
Me
CO2
N2
11
10
9
67%
,
85%
61%
,
,
Scheme 3 Derivatization of hydroxy benziodoxolone in the anodic
oxidation process.
I
I
I
OMe
OH
O
OH
O
MeOH
O
O
O
H2O
Ph
Experimental
,
12
84%
crude
2p
General Procedure for the electrosynthesis of iodosylbenzene
(2a): To an ElectraSyn vial (5 mL) with a stir bar was added LiClO4
(42.6 mg, 0.4 mmol, 2.0 equiv) and 2,2,2-trifluoroethanol (TFE, 3.0
mL). Iodobenzene (1a) (40.8 mg, 0.2 mmol, 1.0 equiv), H2O (18.0
mg, 1.0 mmol, 5.0 equiv) were added to the above solution. The
EletraSyn vial cap equipped with anode (graphite) and cathode
(platinum) were inserted into the mixture. The reaction mixture
was electrolyzed under a constant current of 15 mA for 1.5 h at
room temperature. The EletraSyn vial cap was then removed and
electrodes were rinsed with CH2Cl2. The solvent was removed in
vacuo and residue was washed by H2O (1.0 mL) and diethyl ether
(1.0 mL), dried in vacuo to afford 35.2 mg of iodosylbenzene (2a)
as yellow solid (80% yield).
i. Ac2O
Ac2O
TMS
TMSOTf
ii, TMSCN
I
Ph
I
I
OAc
O
O
CN
O
O
O
O
15
14
13
92%
,
78%
84%
,
,
Finally, as hypervalent iodine(III) reagents can be generated
under electrochemical conditions, the development of anodic
oxidation enabled aryl iodide catalyzed reactions have started to
attract the attention of synthetic chemists more recently.
Nevertheless, stoichiometric amount of aryl iodide is often
needed in most of these in situ anodic oxidation reactions.[9a, 9b]
Here we illustrate two oxidative transformations using 20 mol%
Supporting Information
The supporting information for this article is available on the
www.cjc.wiley-vch.de
© 2019 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2019, 37, XXX－XXX
This article is protected by copyright. All rights reserved.

Running title
Chin. J. Chem.
WWW under https://doi.org/10.1002/cjoc.2018xxxxx.
J. 2017, 23, 15852-15863; (d) Boelke, A.; Finkbeiner, P.; Nachtsheim, B. J.
Atom-economical Group-transfer Reactions with Hypervalent Iodine
Compounds. Beilstein J. Org. Chem. 2018, 14, 1263-1280.
Acknowledgement
(a) Muraki, T.; Togo, H.; Yokoyama, M. Hypervalent Iodine Compounds as
Free Radical Precursors. Rev. Heteroat. Chem. 1997, 17, 213-243; (b) Dohi,
T.; Ito, M.; Yamaoka, N.; Morimoto, K.; Fujioka, H.; Kita, Y. Hypervalent
Iodine(III): Selective and Efficient Single-Electron-Transfer (SET) Oxidizing
Agent. Tetrahedron 2009, 65, 10797-10815; (c) Wang, L.; Liu, J. Synthetic
Applications of Hypervalent Iodine(III) Reagents Enabled by Visible Light
Photoredox Catalysis. Eur. J. Org. Chem. 2016, 2016, 1813-1824; (d) Wang,
X.; Studer, A. Iodine(III) Reagents in Radical Chemistry. Acc. Chem. Res.
2017, 50, 1712-1724.
We are grateful for financial support from the Thousand
Talents Program for Young Scholars, Shenzhen Science and
Technology Innovation Committee (JCYJ20190809142809370),
and Guangdong Provincial Key Laboratory of Catalysis (No.
2020B121201002).
References
(a) Varvoglis, A.; Ed. Hypervalent Iodine in Organic Synthesis, 1996;
(b) Zhdankin, V. V.; Ed. Hypervalent Iodine Chemistry: Preparation,
Structure, and Synthetic Applications of Polyvalent Iodine
Compounds, 2013; (c) Wirth, T.; Hirt, U. H. Hypervalent Iodine
Compounds. Recent Advances in Synthetic Applications. Synthesis 1999,
1271-1287; (d) Moriarty, R. M. Organohypervalent Iodine: Development,
Applications, and Future Directions. J. Org. Chem. 2005, 70, 2893-2903; (e)
Wirth, T. Hypervalent Iodine Chemistry in Synthesis: Scope and New
Directions. Angew. Chem., Int. Ed. 2005, 44, 3656-3665; (f) Zhdankin, V. V.;
Stang, P. J. Chemistry of Polyvalent Iodine. Chem. Rev. 2008, 108,
5299-5358; (g) Wirth, T.; Ed. Hypervalent Iodine Chemistry, 2016; (h)
Brown, M.; Farid, U.; Wirth, T. Hypervalent Iodine Reagents as Powerful
Electrophiles. Synlett 2013, 24, 424-431; (i) Yoshimura, A.; Zhdankin, V. V.
Advances in Synthetic Applications of Hypervalent Iodine Compounds.
Chem. Rev. 2016, 116, 3328-3435.
(a) Tohma, H.; Kita, Y. Hypervalent Iodine Reagents for the Oxidation of
Alcohols and Their Application to Complex Molecule Synthesis. Adv. Synth.
Catal. 2004, 346, 111-124; (b) Romero, R. M.; Woeste, T. H.; Muniz, K.
Vicinal Difunctionalization of Alkenes with Iodine(III) Reagents and
Catalysts. Chem. - Asian J. 2014, 9, 972-983; (c) Singh, F. V.; Wirth, T.
Hypervalent Iodine-Catalyzed Oxidative Functionalizations Including
Stereoselective Reactions. Chem. - Asian J. 2014, 9, 950-971; (d) Dohi, T.;
Kita, Y.; Kita, Y. Hypervalent Iodine-Induced Oxidative Couplings (New
Metal-Free Coupling Advances and Their Applications in Natural Product
Syntheses). Top. Curr. Chem. 2016, 373, 1-23; (e) Murarka, S.; Antonchick
Andrey, P.; Antonchick Andrey, P. Oxidative Heterocycle Formation Using
Hypervalent Iodine(III) Reagents. Top. Curr. Chem. 2016, 373, 75-104; (f)
Xing, L.; Zhang, Y.; Du, Y. Hypervalent Iodine-Mediated Synthesis of
Spiroheterocycles via Oxidative Cyclization. Curr. Org. Chem. 2019, 23,
14-37.
(a) Narayan, R.; Manna, S.; Antonchick, A. P. Hypervalent Iodine(III) in
Direct Carbon-Hydrogen Bond Functionalization. Synlett 2015, 26,
1785-1803; (b) Reddy Kandimalla, S.; Prathima Parvathaneni, S.; Sabitha,
G.; Subba Reddy, B. V. Recent Advances in Intramolecular Metal-Free
Oxidative C-H Bond Aminations Using Hypervalent Iodine(III) Reagents.
Eur. J. Org. Chem. 2019, 2019, 1687-1714; (c) Chen, W. W.; Cuenca, A. B.;
Shafir, A. The Power of Iodane-Guided C−H Coupling: A Group-Transfer
Strategy in Which a Halogen Works for Its Money. Angew. Chem., Int. Ed.
2020, 59, 16294-16309.
(a) Merritt, E. A.; Olofsson, B. Diaryliodonium Salts: A Journey from
Obscurity to Fame. Angew. Chem., Int. Ed. 2009, 48, 9052-9070; (b) Li, Y.;
Hari, D. P.; Vita, M. V.; Waser, J. Cyclic Hypervalent Iodine Reagents for
Atom-Transfer Reactions: Beyond Trifluoromethylation. Angew. Chem.,
Int. Ed. 2016, 55, 4436-4454; (c) Stuart, D. R. Aryl Transfer Selectivity in
Metal-Free Reactions of Unsymmetrical Diaryliodonium Salts. Chem. - Eur.
(a) Miyamoto, K.; Yamashita, J.; Narita, S.; Sakai, Y.; Hirano, K.; Saito, T.;
Wang, C.; Ochiai, M.; Uchiyama, M. Iodoarene-Catalyzed Oxidative
Transformations Using Molecular Oxygen. Chem. Commun. 2017, 53,
9781-9784; (b) Maity, A.; Hyun, S.-M.; Powers, D. C. Oxidase Catalysis via
Aerobically Generated Hypervalent Iodine Intermediates. Nat. Chem.
2018, 10, 200-204; (c) Hyun, S.-M.; Yuan, M.; Maity, A.; Gutierrez, O.;
Powers, D. C. The Role of Iodanyl Radicals as Critical Chain Carriers in
Aerobic Hypervalent Iodine Chemistry. Chem 2019, 5, 2388-2404.
(a) Francke, R.; Little, R. D. Redox Catalysis in Organic Electrosynthesis:
Basic Principles and Recent Developments. Chem. Soc. Rev. 2014, 43,
2492-2521; (b) Fuchigami, T.; Atobe, M.; Inagi S.; Ed. Fundamentals
and Applications of Organic Electrochemistry: Synthesis, Materials,
Devices, 2014; (c) Hammerich, O.; Speiser B.; Ed. Organic
Electrochemistry: Revised and Expanded, Fifth Edition, 2016; (d) Yan, M.;
Kawamata, Y.; Baran, P. S. Synthetic Organic Electrochemical Methods
Since 2000: On the Verge of a Renaissance. Chem. Rev. 2017, 117,
13230-13319; (e) Jiang, Y.; Xu, K.; Zeng, C. Use of Electrochemistry in the
Synthesis of Heterocyclic Structures. Chem. Rev. 2018, 118, 4485-4540; (f)
Kaerkaes, M. D. Electrochemical Strategies for C-H Functionalization and
C-N Bond Formation. Chem. Soc. Rev. 2018, 47, 5786-5865; (g) Okada, Y.;
Chiba, K. Redox-Tag Processes: Intramolecular Electron Transfer and Its
Broad Relationship to Redox Reactions in General. Chem. Rev. 2018, 118,
4592-4630; (h) Tang, S.; Liu, Y.; Lei, A. Electrochemical Oxidative
Cross-coupling with Hydrogen Evolution: A Green and Sustainable Way
for Bond Formation. Chem 2018, 4, 27-45; (i) Waldvogel, S. R.; Lips, S.;
Selt, M.; Riehl, B.; Kampf, C. J. Electrochemical Arylation Reaction. Chem.
Rev. 2018, 118, 6706-6765; (j) Wiebe, A.; Gieshoff, T.; Moehle, S.; Rodrigo,
E.; Zirbes, M.; Waldvogel, S. R. Electrifying Organic Synthesis. Angew.
Chem., Int. Ed. 2018, 57, 5594-5619; (k) Yoshida, J.-i.; Shimizu, A.; Hayashi,
R. Electrogenerated Cationic Reactive Intermediates: The Pool Method
and Further Advances. Chem. Rev. 2018, 118, 4702-4730; (l) Wang, F.;
Stahl, S. S. Electrochemical Oxidation of Organic Molecules at Lower
Overpotential: Accessing Broader Functioinal Groups Compatibility with
Electron-Electron Transfer Mediators. Acc. Chem. Res. 2020, 53, 561-574;
(m) Wu, Y.; Xi, Y.; Zhao, M.; Wang, S. Progress in Electrochemical C-H
Functionalizations of Aromatic Compounds. Chin. J. Org. Chem. 2018, 38,
2590-2605.
(a) Badalyan, A.; Stahl, S. S. Cooperative Electrocatalytic Alcohol
Oxidation with Electron-Proton-Transfer Mediators. Nature 2016, 535,
406-410; (b) Fu, N.; Sauer, G. S.; Saha, A.; Loo, A.; Lin, S. Metal-Catalyzed
Electrochemical Diazidation of Alkenes. Science 2017, 357, 575-579; (c)
Zhao, H.-B.; Liu, Z.-J.; Song, J.; Xu, H.-C. Reagent-Free C-H/N-H
Cross-Coupling: Regioselective Synthesis of N-Heteroaromatics from
Biaryl Aldehydes and NH3. Angew. Chem., Int. Ed. 2017, 56, 12732-12735;
Chin. J. Chem. 2019, 37, XXX－XXX
© 2019 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
This article is protected by copyright. All rights reserved.

First author et al.
Report
(d) Yang, Q.-L.; Wang, X.-Y.; Lu, J.-Y.; Zhang, L.-P.; Fang, P.; Mei, T.-S.
(a) Miller, L. L.; Hoffmann, A. K. Electrochemical Formation of Carbonium
and Iodonium Ions from Alkyl and Aryl iodides. J. Am. Chem. Soc. 1967, 89,
593-597; (b) Hoffelner, H.; Lorch, H. W.; Wendt, H. Anodic Phenyl-onium
Cation Formation. II. Reaction Mechanism and Optimization for the
Anodic Formation of Diphenyliodonium Cations. J. Electroanal. Chem.
Interfacial Electrochem. 1975, 66, 183-194; (c) Peacock, M. J.; Pletcher, D.
The Electrosynthesis of Diaryliodonium Salts. Tetrahedron Lett. 2000, 41,
8995-8998; (d) Peacock, M. J.; Pletcher, D. The Synthesis of
Diaryliodonium Salts by the Anodic Oxidation of Aryl Iodide/Arene
Mixtures. J. Electrochem. Soc. 2001, 148, D37-D42; (e) Watts, K.; Gattrell,
W.; Wirth, T. A Practical Microreactor for Electrochemistry in Flow.
Beilstein J. Org. Chem. 2011, 7, 1108-1114; (f) Francke, R.; Broese, T.;
Roesel, A. F. Electrochemistry of Hypervalent Iodine Compounds. In
Patai’s Chemistry of Functional Groups, Wiley, Hoboken, 2018.
(a) Mueller, P.; Godoy, J. Ruthenium-Catalyzed Oxidations with
Iodosylbenzene Derivatives. Substituent Effects on Selectivity in
Oxidation of Sulfides and Alcohols. Helv. Chim. Acta 1983, 66, 1790-1795;
(b) Katritzky, A. R.; Gallos, J. K.; Durst, H. D. Structure of and Electronic
Interactions in Aromatic Polyvalent Iodine Compounds: a Carbon-13 NMR
Study. Magn. Reson. Chem. 1989, 27, 815-822; (c) Hiller, A.; Patt, J. T.;
Steinbach, J. NMR study on the structure and stability of 4-substituted
aromatic iodosyl compounds. Magn. Reson. Chem. 2006, 44, 955-958.
(a) Zhdankin, V. V. Benziodoxole-Based Hypervalent Iodine Reagents in
Organic Synthesis. Curr. Org. Synth. 2005, 2, 121-145; (b) Hari, D. P.;
Caramenti, P.; Waser, J. Cyclic Hypervalent Iodine Reagents: Enabling
Tools for Bond Disconnection via Reactivity Umpolung. Acc. Chem. Res.
2018, 51, 3212-3225.
Copper-Catalyzed Electrochemical C-H Amination of Arenes with
Secondary Amines. J. Am. Chem. Soc. 2018, 140, 11487-11494; (e) Feng,
E.; Hou, Z.; Xu, H.-C. Electrochemical Synthesis of Tetrasubstituted
Hydrazines by Dehydrogenative N-N Bond Formation. Chin. J. Org. Chem.
2019, 39, 1424-1828. (f) Cao, Z.; Liu, J.; Chu, Y.; Zhao, F.; Zhu, Y.; She, Y.
Paired Electro-synthesis of Aryl Nitriles. Chin. J. Org. Chem. 2019, 39,
2499-2506.
(a) Elsherbini, M.; Wirth, T. Hypervalent Iodine Reagents by Anodic
Oxidation:
A Powerful Green Synthesis. Chem. - Eur. J. 2018, 24,
13399-13407; (b) Francke, R. Electrogenerated Hypervalent Iodine
Compounds as Mediators in Organic Synthesis. Curr. Opin. Electrochem.
2019, 15, 83-88; (c) Fuchigami, T.; Fujita, T. Electrolytic Partial
Fluorination of Organic Compounds. 14. The First Electrosynthesis of
Hypervalent Iodobenzene Difluoride Derivatives and Its Application to
Indirect Anodic gem-Difluorination. J. Org. Chem. 1994, 59, 7190-7192; (d)
Hara, S.; Hatakeyama, T.; Chen, S.-Q.; Ishi-i, K.; Yoshida, M.; Sawaguchi,
M.; Fukuhara, T.; Yoneda, N. Electrochemical Fluorination of β-Dicarbonyl
Compounds Using p-Iodotoluene Difluoride as a Mediator. J. Fluorine
Chem. 1998, 87, 189-192; (e) Kajiyama, D.; Inoue, K.; Ishikawa, Y.;
Nishiyama, S.
A
Aynthetic Approach to Carbazoles Using
Electrochemically Generated Hypervalent Iodine Oxidant. Tetrahedron
2010, 66, 9779-9784; (f) Sawamura, T.; Kuribayashi, S.; Inagi, S.;
Fuchigami, T. Use of Task-Specific Ionic Liquid for Selective
Electrocatalytic Fluorination. Org. Lett. 2010, 12, 644-646; (g) Kajiyama,
D.; Saitoh, T.; Nishiyama, S. Application of electrochemically generated
hypervalent iodine oxidant to natural products synthesis.
Electrochemistry 2013, 81, 319-324; (h) Broese, T.; Francke, R.
Electrosynthesis Using a Recyclable Mediator-Electrolyte System Based
on Ionically Tagged Phenyl Iodide and 1,1,1,3,3,3-Hexafluoroisopropanol.
Org. Lett. 2016, 18, 5896-5899; (i) Gao, W.-C.; Xiong, Z.-Y.; Pirhaghani, S.;
Wirth, T. Enantioselective Electrochemical Lactonization Using Chiral
Iodoarenes as Mediators. Synthesis 2019, 51, 276-284; (j) Haupt, J. D.;
Berger, M.; Waldvogel, S. R. Electrochemical Fluorocyclization of
N-Allylcarboxamides to 2-Oxazolines by Hypervalent Iodine Mediator. Org.
Lett. 2019, 21, 242-245; (k) Moeckel, R.; Babaoglu, E.; Hilt, G.
(a) Yusubov, M. S.; Maskaev, A. V.; Zhdankin, V. V. Iodonium Salts in
Organic Synthesis. ARKIVOC 2011, 370-409; (b) Aradi, K.; Toth, B. L.;
Tolnai, G. L.; Novak, Z. Diaryliodonium Salts in Organic Syntheses: A
Useful Compound Class for Novel Arylation Strategies. Synlett 2016, 27,
1456-1485; (c) Olofsson, B. Arylation with Diaryliodonium Salts. Top. Curr.
Chem. 2016, 373, 135-166; (d) Chatterjee, N.; Goswami, A. Synthesis and
Application of Cyclic Diaryliodonium Salts:
A
Platform for
Bifunctionalization in a Single Step. Eur. J. Org. Chem. 2017, 2017,
3023-3032; (e) Pacheco-Benichou, A.; Besson, T.; Fruit, C.
Diaryliodoniums Salts as Coupling Partners for Transition-Metal Catalyzed
C- and N-arylation of Heteroarenes. Catalysts 2020, 10, 483.
Iodine(III)-Mediated
Electrochemical
Trifluoroethoxylactonisation:
Rational Reaction Optimisation and Prediction of Mediator Activity. Chem.
- Eur. J. 2018, 24, 15781-15785; (l) Koleda, O.; Broese, T.; Noetzel, J.;
Roemelt, M.; Suna, E.; Francke, R. Synthesis of Benzoxazoles Using
Electrochemically Generated Hypervalent Iodine. J. Org. Chem. 2017, 82,
11669-11681; (m) Elsherbini, M.; Winterson, B.; Alharbi, H.;
Folgueiras-Amador, A. A.; Genot, C.; Wirth, T. Continuous-Flow
Electrochemical Generator of Hypervalent Iodine Reagents: Synthetic
Applications. Angew. Chem., Int. Ed. 2019, 58, 9811-9815. (n) Maity, A.;
Frey, B. L.; Hoskinson, N. D.; Powers, D. C. Electrocatalytic C-N Coupling
via Anodically Generated Hypervalent Iodine Intermediates. J. Am. Chem.
Soc. 2020, 142, 4990-4995. (o) Qian, P.; Zha, Z.; Wang, Z. Recent
Advances in C-H Functionalization with Electrochemistry and Various
Iodine-Containing Reagents. ChemElectroChem 2020, 7, 2527-2544; (P)
Doobary, S.; Sedikides, A. T.; Caldora, H. P.; Poole, D. L.; Lennox, A. J. J.
Electrochemical Vicinal Difluorination of Alkenes: Scalable and Amenable
to Electron-rich Substrates. Angew. Chem., Int. Ed. 2020, 59, 1155-1160;
(q) Zhang, H.; Tang, R.; Shi, X.; Xie, L.; Wu, J. Recent Advances in Organic
Electrochemical Synthesis and Application of Hypervalent Iodine
Reagents. Chin. J. Org. Chem. 2019, 39, 1837-1845.
(a) Moriarty, R. M.; Condeiu, C.; Tao, A.; Prakash, O. New
Organohypervalent Iodine Reagents for α-Methylphosphonylations and
α-Diphenyl- and α-Dimethylphosphinylations. Tetrahedron Lett. 1997, 38,
2401-2404; (b) Murphy, G. K.; Racicot, L.; Carle, M. S. The Chemistry
between Hypervalent Iodine(III) Reagents and Organophosphorus
Compounds. Asian J. Org. Chem. 2018, 7, 837-851.
(a) Koser, G. F.; Wettach, R. H. Synthesis and Characterization of
[Methoxy(tosyloxy)iodo]benzene, an Acyclic Monoalkoxyiodinane. J. Org.
Chem. 1980, 45, 4988-4989; (b) Yoshimura, A.; Nguyen, K. C.; Rohde, G. T.;
Postnikov, P. S.; Yusubov, M. S.; Zhdankin, V. V. Hypervalent Iodine
Reagent Mediated Oxidative Heterocyclization of Aldoximes with
Heterocyclic Alkenes. J. Org. Chem. 2017, 82, 11742-11751.
(a) Souto, J. A.; Zian, D.; Muniz, K. Iodine(III)-Mediated Intermolecular
Allylic Amination under Metal-Free Conditions. J. Am. Chem. Soc. 2012,
134, 7242-7245; (b )Souto, J. A.; Martinez, C.; Velilla, I.; Muniz, K. Defined
Hypervalent Iodine(III) Reagents Incorporating Transferable Nitrogen
Groups: Nucleophilic Amination through Electrophilic Activation. Angew.
Chem., Int. Ed. 2013, 52, 1324-1328.
www.cjc.wiley-vch.de
© 2019 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2019, 37, XXX－XXX
This article is protected by copyright. All rights reserved.

Running title
Chin. J. Chem.
(a) Dauban, P.; Dodd, R. H. Iminoiodanes and C-N Bond Formation in
(a) Weiss, R.; Seubert, J.; Hampel, F. α-(Aryliodonio) diazo Compounds:
SN Reactions at the α-C Atom as a Novel Reaction of Diazo Compounds.
Angew. Chem. 1994, 106, 2038-2039; (b) Taylor, M. T.; Nelson, J. E.; Suero,
M. G.; Gaunt, M. J. A Protein Functionalization Platform Based on
Selective Reactions at Methionine Residues. Nature 2018, 562, 563-568.
Organic Synthesis. Synlett 2003, 1571-1586; (b) Wang, L.; Agnew, D. W.;
Yu, X.; Figueroa, J. S.; Cohen, S. M. A Metal-Organic Framework with
Exceptional Activity for C-H Bond Amination. Angew. Chem., Int. Ed. 2018,
57, 511-515.
(a) Zhdankin, V. V.; Stang, P. J. Alkynyliodonium Salts in Organic Synthesis.
Tetrahedron 1998, 54, 10927-10966; (b) Brand, J. P.; Waser, J.
Electrophilic Alkynylation. The Dark Side of Acetylene Chemistry. Chem.
Soc. Rev. 2012, 41, 4165-4179; (c) Waser, J. Alkynylation with Hypervalent
Iodine Reagents. Top. Curr. Chem. 2016, 373, 187-222.
(a) Mueller, P. Asymmetric Transfer of Carbenes with Phenyliodonium
Ylides. Acc. Chem. Res. 2004, 37, 243-251; (b) Malamidou-Xenikaki, E.;
Spyroudis, S. Zwitterionic Iodonium Compounds: Useful Tools in Organic
Synthesis. Synlett 2008, 2725-2740.
(The following will be filled in by the editorial staff)
Manuscript received: XXXX, 2019
Manuscript revised: XXXX, 2019
Manuscript accepted: XXXX, 2019
Accepted manuscript online: XXXX, 2019
Version of record online: XXXX, 2019
Chin. J. Chem. 2019, 37, XXX－XXX
© 2019 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
This article is protected by copyright. All rights reserved.

First author et al.
Report
Entry for the Table of Contents
I
I
(III)
Page No.
2 H+
+
+
H2
R
R
Synthesis of Diverse Aryliodine(III) Reagents by
Anodic Oxidation
efficiency
selectivity
high
high
OTf
L
O
I
L
I
I
I
O
O
R
L
R
R
R'
mild conditions
benziodoxoles
iodosylarenes
(difunctionaliodo)
arenes
diaryliodonium
salts
general
applicability
An anodic oxidation enabled efficient synthesis of hypervalent iodine(III) reagents from aryl
iodides is demonstrated. Under mild electrochemical conditions, a range of aryliodine(III) reagents
including iodosylarenes, (difunctionaliodo)arenes, benziodoxoles and diaryliodonium salts can be
efficiently synthesized and derivatized in good to excellent yields with high selectivity. As only
electrons serve as the oxidation reagents, this method offers a more straightforward and
sustainable manner avoiding the use of expensive or hazardous chemical oxidants.
Bing Zu, Jie Ke, Yonghong Guo, and Chuan He*
www.cjc.wiley-vch.de
© 2019 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2019, 37, XXX－XXX
This article is protected by copyright. All rights reserved.