Diaryliodoniums by Rhodium(III)-Catalyzed C-H Activation: Mild Synthesis and Diversified Functionalizations

Article abstract of DOI:10.1002/anie.201502278

Diaryliodonium salts play an increasingly important role as an aryl source. Reported is the first synthesis of diaryliodoniums by rhodium(III)-catalyzed C-H hyperiodination of electron-poor arenes under chelation assistance. This C-I coupling reaction occurred at room temperature with high regio-selectivity and functional-group compatibility. Subsequent diversified nucleophilic functionalization of a diaryliodonium allowed facile construction of C-C, C-N, C-O, C-S, C-P and C-Br bonds, and in all cases the initial functionalization occurred at the arene containing the chelating-group. Bonds aplenty: Diaryliodonium salts were synthesized for the first time from electron-poor arenes by the title reaction. The diaryliodoniums can be readily functionalized by nucleophiles with high chemoselectivity, thus leading to C-C, C-S, C-N, C-P, and C-Br bond formation. Cp=C₅Me₅, DG=directing group, Ts=4-toluenesulfonyl.

Full text of DOI:10.1002/anie.201502278

Angewandte
Chemie
International Edition: DOI: 10.1002/anie.201502278
Hypervalent Compounds
German Edition:
DOI: 10.1002/ange.201502278
À
Diaryliodoniums by Rhodium(III)-Catalyzed C H Activation: Mild
Synthesis and Diversified Functionalizations**
Fang Xie, Zhipeng Zhang, Xinzhang Yu, Guodong Tang, and Xingwei Li*
Abstract: Diaryliodonium salts play an increasingly important
role as an aryl source. Reported is the first synthesis of
reactions have shown very broad substrate scope in the mild
and selective functionalization of arenes.[6] This broad sub-
strate scope is in part ascribable to the high polarity and
reactivity of the RhIII–aryl bond, in which the aryl ligand
functions as a relatively strong nucleophilic aryl source and
can be regenerated.[7] We reasoned that rhodium-catalyzed
À
diaryliodoniums by rhodium(III)-catalyzed C H hyperiodi-
nation of electron-poor arenes under chelation assistance. This
À
C I coupling reaction occurred at room temperature with high
regio-selectivity and functional-group compatibility. Subse-
À
quent diversified nucleophilic functionalization of a diarylio-
C H activation of electron-poor arenes may be extended to
the synthesis of unsymmetrical diaryliodonium salts. Indeed,
À
À
À
À
donium allowed facile construction of C C, C N, C O, C S,
we[8] and others[9] recently demonstrated that arene C H
activation and hypervalent iodines could be successfully
combined by using a [Cp*RhIII] catalyst, although in all
cases the iodine(III) reagents delivered no iodine to the
À
À
À
C P and C Br bonds, and in all cases the initial functional-
ization occurred at the arene containing the chelating-group.
H
ypervalent iodine compounds are versatile electrophiles
À
with the appealing combination of high reactivity, stability,
selectivity, and environmental friendliness.[1] Diaryliodonium
salts are particularly useful,[2] and they are typically accessed
by transmetalation between a boron reagent and a simple
iodine(III) source,[3] or by electrophilic functionalization of an
electron-rich arene (Scheme 1).[4] The latter method is
appealing because no prior functionalization of the arene is
necessary. However, the restriction to electron-rich arenes
may significantly limit the applications.
product. We now report a rhodium(III)-catalyzed C H
activation strategy for the mild hyperiodination of electron-
poor arenes. Significantly, these diaryliodonium products can
be selectively and conveniently functionalized by a large array
of nucleophiles.
We embarked on our studies with the optimization of the
reaction conditions for the coupling between 2-phenylpyr-
idine (1a) and Koser’s reagent (2) catalyzed by [{RhCp*Cl2}2]
(4 mol%) (Table 1). When using AgSbF6 as an additive in
CH2Cl2, no ortho phenylation product was detected. Instead,
the hyperiodination product 3a was isolated in 32% yield
(entry 1). The yield of 3a was doubled when the solvent was
It has been well demonstrated that unactivated arenes can
À
be readily functionalized by metal-catalyzed C H activa-
III
tion.[5] In particular, [Cp*Rh ]-catalyzed C H activation
À
Table 1: Optimization studies.
Entry
Iodine(III)
Additive
Solvent
Yield [%][a]
1[b]
2[b]
3[b]
4[b]
5[b]
6[b]
7[c]
PhI(OH)OTs
PhI(OH)OTs
PhI(OH)OTs
PhI(OH)OTs
PhI(OH)OTs
PhI(OH)OTs
PhI(OAc)2/PTSA
PhI(OAc)2/PTSA
PhI(OAc)2/PTSA
PhI(OAc)2/PTSA
AgSbF6
AgSbF6
CuO
CH2Cl2
acetone
acetone
TFE
acetone
acetone
acetone
acetone
acetone
acetone
acetone
32
65
64
35
48
24
70
58
74
Scheme 1. Synthesis of diaryliodonium salts. PTSA=para-toluene sul-
fonic acid.
CuO
Cu(OAc)2
Ag2O
AgSbF6
–
CuO
CuO
8[c]
[*] Dr. F. Xie, Z. Zhang, Dr. X. Yu, G. Tang, Prof. Dr. X. Li
Dalian Institute of Chemical Physics, Chinese Academy of Science
Dalian 116023 (China)
9[c]
10[d]
11[c]
85
<5
E-mail: xwli@dicp.ac.cn
=
PhI O/PTSA
–
Dr. X. Yu
[a] Yield of product isolated after column chromatography. [b] Reaction
conditions: 1a (0.2 mmol), iodine(III) (0.4 mmol), additive
Department of Chemistry and Chemical Engineering, Taiyuan
Institute of Technology, Taiyuan 030008 (China)
(0.04 mmol), [{RhCp*Cl2}2] (0.008 mmol), solvent (2 mL), 2 h, RT under
air. [c] Reaction conditions: PhI(OAc)2 (0.3 mmol), p-TsOH·H2O
(0.3 mmol), acetone (2 mL), 1 h. Then 1a (0.2 mmol), additive
(0.04 mmol), and [{RhCp*Cl2}2] (0.008 mmol) were then added and were
stirred under air for 2 h. [d] PhI(OAc)2 (0.36 mmol) was used.
Cp*=C5Me5, TFE=2,2,2-trifluoroethanol, Ts=4-toluenesulfonyl.
[**] Financial support from the NNSFC (Nos. 21272231, 21402190, and
21472186) and from the Chinese Academy of Sciences is gratefully
acknowledged.
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/anie.201502278.
Angew. Chem. Int. Ed. 2015, 54, 1 – 6
ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1
These are not the final page numbers!

.
Angewandte
Communications
switched to acetone (entry 2). Further optimization using
a combination of PhI(OAc)2 (PIDA) and PTSA, which
afforded HOAc and 2 in situ, improved the yield (entries 7
and 9). Finally, 3a was isolated in 85% yield when the amount
of PIDA was increased to 1.8 equivalents with CuO being an
additive (Conditions A; entry 10). Control experiments veri-
fied that no product was detected when the rhodium catalyst
was omitted.
The scope of the coupling system was next explored under
the optimized reaction Conditions A (Scheme 2). Simple or 2-
Scheme 2. Hyperiodination assisted by heterocycles. [a] Conditions A:
PIDA (0.36 mmol) and PTSA (0.3 mmol) were stirred in acetone
(2 mL) under air for 1 h. Arene (0.2 mmol), [{Cp*RhCl2}2]
(0.008 mmol), and CuO (0.04 mmol) were added and was stirred for
another 2 h. Conditions B: PIDA (0.4 mmol) and PTSA (0.4 mmol)
were stirred in acetone (2 mL) under air for 1 h. Arene (0.2 mmol),
[{Cp*RhCl2}2] (0.008 mmol), CuO (0.04 mmol), PIDA (1.5 equiv), 2 h.
[b] Yield of isolated products.
Scheme 3. Hyperiodination of oxime ethers. [a] Conditions C: PIDA
(0.4 mmol) and PTSA (0.4 mmol) were stirred in HFIP (2 mL) under
air for 1 h. Oxime (0.2 mmol), [{Cp*RhCl2}2] (0.008 mmol), Ag2O
(0.04 mmol), and PIDA (0.3 mmol) were added, followed by stirring
for 2 h. [b] Yield of the isolated product. HFIP=1,1,1,3,3,3-hexafluoro-
2-propanol.
phenylpyridines substituted with electron-donating groups
(EDGs) underwent smooth coupling and the iodoniums 3a–g
were isolated in good to high yields. However, introduction of
an electron-withdrawing group (EWG) onto either the phenyl
or the heterocyclic ring retarded the reaction. Fortunately,
introducing a second batch of PIDA improved the catalytic
efficiency (Conditions B). Under these two reaction condi-
tions, EDG, EWG, and halogen substituents at different
positions were fully tolerated, and the directing group (DG)
was extended to include pyrimidine and pyrazole rings. The
coupling of arenes bearing a meta substituent occurred at the
crystallography (CCDC 1052195).[10] The HFIP is a polar
solvent which activated the iodonium(III) reagent.[11] While
the Ag2O additive is unnecessary for oximes bearing an EDG
(3r–w), it significantly improved the yield for those with an
EWG or a halogen substituent. Under the globally optimized
reaction Conditions C, a broad spectrum of halogenated,
electron-rich, and electron-poor oxime ethers is fully toler-
ated. The iminyl substituent can be smoothly extended to
other alkyl (3s, 3t, and 3ai) and aryl (3x) groups. Significantly,
oxime ethers of benzaldehyde are equally competent,
À
less hindered C H bond (3g, 3h, and 3n), thus suggesting that
the site selectivity is dictated by steric effects. In addition, the
arene is not limited to a benzene ring, and 2-pyridylthiophene
proved to be a viable substrate (3o).
À
Extension of the arene substrate to oxime ethers met with
failure under both reaction Conditions A and B. It turned out
that the choice of solvent is crucial. Switching to HFIP as
a solvent and Ag2O (20 mol%) as an additive significantly
improved the efficiency of hyperiodination of the oxime ether
1r (Scheme 3), and the diaryliodonium 3r was isolated in
84% yield, and was additionally characterized by X-ray
although they are generally much less efficient in C H
activation.[12] The mild reaction conditions and high polarity
of the HFIP solvent may contribute to the applicability of
such substrates. In all cases, high site selectivity and good to
high yields (56–89%) were obtained, and for meta-substituted
À
arene substrates the C H functionalization occurred at the
less hindered site except for the product 3z, which bears
2
www.angewandte.org
ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2015, 54, 1 – 6
These are not the final page numbers!

Angewandte
Chemie
a meta-F substituent. In addition, the high-yielding synthesis
of 3r at a scale of 3 mmol using a reduced catalyst loading
(2 mol%) can also be achieved.
The rich chemistry of diaryliodonium as an arylating
reagent has been increasingly explored and it provides
a stepping stone for functionalized arenes, as in the seminal
work by the groups of Gaunt and Sanford.[13] By taking full
advantage of the electrophilicity of the diaryliodonium salt
3r, we next explored its synthetic applications (Scheme 4). In
a-Trimethylsiloxystyrene even reacted (À408C to RT) to
afford the phenacylation product 19 in 60% yield. By
following a procedure recently reported by Modha and
Greaney,[17] copper(I)-catalyzed one-pot coupling with
a simple indole led to selective and sequential difunctional-
ization at the 1- and 3-positions (20), in which both aryl
groups of the iodonium salt have been utilized. In all cases,
only the DG-bearing arene ring was initially functionalized.
Notably, one-pot functionalization of acetophenone O-
methyl oxime (1r) with N-methylindole and with NaN3
afforded 18 and 14, respectively, albeit in somewhat lower
yield. Besides copper catalysis, palladium-catalyzed Sonoga-
shira and Suzuki couplings of 3r have also been achieved
(products 21 and 22; see the Supporting Information).[18]
Our functionalization reactions are complementary to
those known using unsymmetrical diaryliodoniums, in which
an aryl group (such as mesityl) is typically sterically deacti-
vated.[19] To further probe the origin of the biased aryl groups,
we performed the azidation of the iodonium salt 23 (synthe-
sized following reaction Conditions C). The fact that only the
azide 14 was detected [79% yield; Eq. (1)] indicated that the
two aryl groups in 23 were differentiated, likely by the ligating
effect of the oxime DG. We propose that chelation-assisted
À
C I oxidative addition to copper(I) affords a copper(III)
À
species, C C reductive elimination of which furnishes the
final functionalization product (Scheme 4 and see the Sup-
porting Information).[15d,20]
Scheme 4. Copper-catalyzed diverse nucleophilic functionalizations.
See the Supporting Information for details. DCE=1,2-dichloroethane,
DMEDA=N,N’-dimethylethylenediamine, DMF=N,N-dimethylforma-
mide, DIPEA=N,N-diisopropylethylamine, DTBMP=2,6-di-tert-butyl-4-
methylpyridine, TMS=trimethylsilyl.
Preliminary mechanistic studies have been performed to
À
briefly explore the mechanism. To probe the relevancy of C
H
activation,
a
cyclometalated [Cp*RhIIICl] complex
(7 mol%) was prepared and was designated as a catalyst for
À
the C H functionalization of 2-phenylpyridine under other-
wise identical reaction conditions, from which 3a was isolated
À
the absence of any external nucleophile, Cu(OTf)2-catalyzed
reductive coupling afforded the tosylation product 4 in good
yield. Phenoxylation using NaOPh produced the ether 5 in
in a yield of 77% (Scheme 5a). This result suggests that C H
À
66% yield. C S coupling as in trifluoromethylthiolation,
sulfonylation, and arylthiolation (6–9) has been readily
achieved using the corresponding AgSCF3, sodium sulfinates,
and mercaptan. Of note, the reaction of the Langlois reagent
is sulfonyl-retentive, thus indicating that a radical pathway is
not operational.[14] Analogously, smooth amination, amida-
À
tion, imidation, azidation, and nitration afforded the C N
coupled[15] products (10–15) in good to high yield starting
from the corresponding secondary amine or sodium salts. The
mild hetero-functionalization can be further extended to
bromination using NaBr (17) and to phosphorylation (16)
using diphenylphosphine oxide.
Carbofunctionalization of the iodonium salt 3r also
proved successful (Scheme 4). Cu(OTf)2-catalyzed attack of
N-methylindole afforded the 3-arylated indole 18 in the
presence of 1,6-di-tert-butyl-4-methylpyridine (DTBMP).[16]
Scheme 5. Mechanistic considerations.
Angew. Chem. Int. Ed. 2015, 54, 1 – 6
ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
3
These are not the final page numbers!

.
Angewandte
Communications
À
[2] Selected examples: a) N. R. Deprez, D. Kalyani, A. Krause,
M. S. Sanford, J. Am. Chem. Soc. 2006, 128, 4972; b) S. R.
Neufeldt, M. S. Sanford, Adv. Synth. Catal. 2012, 354, 3517; c) G.
Fumagalli, S. Boyd, M. F. Greaney, Org. Lett. 2013, 15, 4398;
d) N. Ichiishi, A. J. Canty, B. F. Yates, M. S. Sanford, Org. Lett.
2013, 15, 5134.
[3] a) M. A. Carroll, V. W. Pike, D. A. Widdowson, Tetrahedron
Lett. 2000, 41, 5393; b) M. Yoshida, K. Osafune, S. Hara,
Synthesis 2007, 1542; c) M. Bielawski, D. Aili, B. Olofsson, J.
Org. Chem. 2008, 73, 4602.
activation is likely involved. To further probe the C H
activation process, the kinetic isotope effect (KIE) of hyper-
iodination of the oxime 1r has been measured (Scheme 5b).
An intermolecular competition using an equimolar amount of
1r and [D5]-1r at low conversion gave a KIE value of 2.0, thus
À
indicating that C H cleavage might be involved in the rate-
limiting step.[21]
A plausible mechanism[22] for this C I coupling may
À
involve coordination of PhI(OH)OTs to give the rhodium-
(III) intermediate A, followed by nucleophilic 1,2-migration
of the aryl group to the iodine with concomitant displacement
of the OH leaving group which is activated by TsOH and/or
HFIP to afford the rhodium(III) intermediate B (Sche-
me 5c).[7c,8a,12c] Dissociation of the coupled product furnishes
a [Cp*RhIII] intermediate which allows the turnover of the
catalytic cycle. The CuO and Ag2O additives possibly activate
the hypervalent iodine reagent and the catalyst by removal of
the Cl ligand. We noted the difference of reaction patterns in
our previous azidation system with PhI(N3)OTs being a likely
intermediate,[8a] where the azide ligand is soft and readily
undergoes umpolung upon coordination to iodine(III), thus
giving higher reactivity. In the current system the OH group in
PhI(OH)OTs is a hard ligand, and the Rh–Ar bond reacts
preferentially with the iodine atom.
[4] a) T. Kitamura, J. Matsuyuki, H. Taniguchi, Synthesis 1994, 147;
b) R. Kitamura, K. Furuki, K. Nagata, H. Taniguchi, P. J. Stang,
J. Org. Chem. 1992, 57, 6810; c) M. Bielawski, B. Olofsson,
Chem. Commun. 2007, 2521; d) M. Bielawski, B. Olofsson, Org.
Synth. 2009, 86, 308; e) P. P. Onysꢀko, T. V. Kim, O. I. Kiseleva,
Y. V. Rassukana, A. A. Gakh, J. Fluorine Chem. 2009, 130, 501.
[5] Selected reviews: a) R. Giri, B.-F. Shi, K. M. Engle, N. Maugel,
J.-Q. Yu, Chem. Soc. Rev. 2009, 38, 3242; b) D. A. Colby, R. G.
Bergerman, J. A. Ellman, Chem. Rev. 2009, 109, 624; c) T. W.
Lyons, M. S. Sanford, Chem. Rev. 2010, 110, 1147; d) L.
McMurray, F. O’Hara, M. J. Gaunt, Chem. Soc. Rev. 2011, 40,
1885; e) W. R. Gutekunst, P. S. Baran, Chem. Soc. Rev. 2011, 40,
1976; f) C. S. Yeung, V. M. Dong, Chem. Rev. 2011, 111, 1215;
g) J. Wencel-Delord, T. Droge, F. Liu, F. Glorius, Chem. Soc. Rev.
2011, 40, 4740; h) S. H. Cho, J. Y. Kim, J. Kwak, S. Chang, Chem.
Soc. Rev. 2011, 40, 5068; i) L. Ackermann, R. Vicente, A. R.
Kapdi, Angew. Chem. Int. Ed. 2009, 48, 9792; Angew. Chem.
2009, 121, 9976.
In summary, we have achieved the first synthesis of diaryl
À
[6] For reviews on rhodium(III)-catalyzed C H activation, see a) T.
À
iodonium salts by rhodium-catalyzed C H hyperiodination of
Satoh, M. Miura, Chem. Eur. J. 2010, 16, 11212; b) G. Song, F.
Wang, X. Li, Chem. Soc. Rev. 2012, 41, 3651; c) N. Kuhl, N.
Schrçder, F. Glorius, Adv. Synth. Catal. 2014, 356, 1443; d) G.
Song, X. Li, Acc. Chem. Res. 2015, 48, 1007.
electron-poor arenes. Nitrogen chelators such as pyridine,
pyrimidine, pyrazole, and oxime proved to be viable directing
groups. Subsequent diverse nucleophilic functionalization of
the iodonium product provided a stepping stone to access
a broad spectrum of carbo- and hetero-functionalized arenes
under copper catalysis. In all cases the initial functionalization
occurred at the DG-containing arene. The functionalization
[7] a) Y. Li, B.-J. Li, W.-H. Wang, W.-P. Huang, X.-S. Zhang, K.
Chen, Z.-J. Shi, Angew. Chem. Int. Ed. 2011, 50, 2115; Angew.
Chem. 2011, 123, 2163; b) L. Yang, C. A. Correia, C.-J. Li, Adv.
Synth. Catal. 2011, 353, 1269; c) C. Grohmann, H. Wang, F.
Glorius, Org. Lett. 2012, 14, 656; d) N. Schrçder, J. W. Delord, F.
Glorius, J. Am. Chem. Soc. 2012, 134, 8298; e) A. Wangweer-
awong, R. G. Bergman, J. A. Ellman, J. Am. Chem. Soc. 2014,
136, 8520.
[8] a) F. Xie, Z. Qi, X. Li, Angew. Chem. Int. Ed. 2013, 52, 11862;
Angew. Chem. 2013, 125, 12078; b) F. Xie, Z. Qi, S. Yu, X. Li, J.
Am. Chem. Soc. 2014, 136, 4780; c) H. Wang, F. Xie, Z. Qi, X. Li,
Org. Lett. 2015, 17, 920.
À
can be one-pot starting from the arene. Streamlining of C
hyperiodination and nucleophilic functionalization overcame
À
some limitations of the C H functionalization of arenes
because tedious individual optimization of the conditions of
À
À
metal catalyzed C H activation and C E (E = C, O, N, S, P,
Br) coupling is no longer necessary. The mild hyperiodination
conditions and the rich chemistry of hypervalent iodine make
this method attractive, and future work will be directed to
detailed mechanistic studies and extension of the arenes.
[9] a) H. Zhao, Y. Shang, W. Su, Org. Lett. 2013, 15, 5106; b) C.
Feng, T.-P. Loh, Angew. Chem. Int. Ed. 2014, 53, 2722; Angew.
Chem. 2014, 126, 2760; c) K. D. Collins, F. Lied, F. Glorious,
Chem. Commun. 2014, 50, 4459.
À
Keywords: arenes · C H activation · copper ·
hypervalent compounds · rhodium
[10] CCDC 1052195 (3r-CH2Cl2) contains the supplementary crys-
tallographic data for this paper. These data can be obtained free
of charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif.
[11] a) T. Dohi, K. Morimoto, Y. Kiyono, A. Maruyama, H. Tohma,
Y. Kita, Chem. Commun. 2005, 2930; b) A. P. Antonchick, R.
Samanta, K. Kulikov, J. Lategahn, Angew. Chem. Int. Ed. 2011,
50, 8605; Angew. Chem. 2011, 123, 8764; c) S. Manna, A. P.
Antonchick, Angew. Chem. Int. Ed. 2014, 53, 7324; Angew.
Chem. 2014, 126, 7452.
[1] Reviews: a) A. Varvoglis, The Organic Chemistry of Polycoordi-
nated Iodine, VCH, Weinheim, 1992; b) V. V. Zhdankin, P. J.
Stang, Chem. Rev. 2008, 108, 5299; c) V. V. Zhdankin, P. J. Stang,
Chem. Rev. 2002, 102, 2523; d) T. Wirth, Angew. Chem. Int. Ed.
2005, 44, 3656; Angew. Chem. 2005, 117, 3722; e) R. D.
Richardson, T. Wirth, Angew. Chem. Int. Ed. 2006, 45, 4402;
Angew. Chem. 2006, 118, 4510; f) K. C. Nicolaou, T. Montagnon,
P. S. Baran, Y.-L. Zhong, J. Am. Chem. Soc. 2002, 124, 2245;
g) J. P. Brand, J. Waser, Chem. Soc. Rev. 2012, 41, 4165; h) E. A.
Merritt, B. Olofsson, Angew. Chem. Int. Ed. 2009, 48, 9052;
Angew. Chem. 2009, 121, 9214.
[12] Z. Shi, D. C. Koester, M. Boultadakis-Arapinis, F. Glorius, J.
Am. Chem. Soc. 2013, 135, 12204.
[13] a) R. Phipps, M. J. Gaunt, Science 2009, 323, 1593; b) A. Bigot,
A. E. Williamson, M. J. Gaunt, J. Am. Chem. Soc. 2011, 133,
13778; c) B. S. L. Collins, M. G. Suero, M. J. Gaunt, Angew.
Chem. Int. Ed. 2013, 52, 5799; Angew. Chem. 2013, 125, 5911;
d) E. Cahard, N. Bremeyer, M. J. Guant, Angew. Chem. Int. Ed.
2013, 52, 9284; Angew. Chem. 2013, 125, 9454; e) F. Zhang, S.
4
www.angewandte.org
ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2015, 54, 1 – 6
These are not the final page numbers!

Angewandte
Chemie
Das, A. J. Walkinshaw, A. Casitas, M. Taylor, M. G. Suero, M. J.
Gaunt, J. Am. Chem. Soc. 2014, 136, 8851; f) A. M. Wagner,
M. S. Sanford, Org. Lett. 2011, 13, 288; g) A. M. Wagner, M. S.
Sanford, J. Org. Chem. 2014, 79, 2263.
[18] a) S. K. Kang, S.-K. Yoon, Y.-M. Kim, Org. Lett. 2001, 3, 2697;
b) S.-K. Kang, H.-W. Lee, S.-B. Jang, P.-S. Ho, J. Org. Chem.
1996, 61, 4720.
[19] J. Malmgren, S. Santoro, N. Jalalian, F. Himo, B. Olofsson, Chem.
Eur. J. 2013, 19, 10334.
[20] N. Ichiishi, A. J. Canty, B. F. Yates, M. S. Sanford, Organo-
metallics 2014, 33, 5525.
[21] E. M. Simmons, J. F. Hartwig, Angew. Chem. Int. Ed. 2012, 51,
3066; Angew. Chem. 2012, 124, 3120.
[14] a) B. R. Langlois, E. Laurent, N. Roidot, Tetrahedron Lett. 1991,
32, 7525; b) Y. Ji, T. Brueckl, R. D. Baxter, Y. Fujiwara, I. B.
Seiple, S. Su, D. G. Blackmond, P. S. Baran, Proc. Natl. Acad. Sci.
USA 2011, 108, 14411.
[15] Selected recent examples: a) D. Lubriks, I. Sokolovs, E. Suna, J.
Am. Chem. Soc. 2012, 134, 15436; b) I. Sokolovs, D. Lubriks, E.
Suna, J. Am. Chem. Soc. 2014, 136, 6920.
[22] The alternative mechanism of oxidative addition of PhI(O-
H)OTs to the RhIII to give a RhV species is also possible.
[16] R. J. Phipps, N. P. Grimster, M. J. Gaunt, J. Am. Chem. Soc. 2008,
130, 8172.
Received: March 12, 2015
[17] S. G. Modha, M. F. Greaney, J. Am. Chem. Soc. 2015, 137, 1416.
Published online: && &&, &&&&
Angew. Chem. Int. Ed. 2015, 54, 1 – 6
ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
5
These are not the final page numbers!

.
Angewandte
Communications
Communications
Hypervalent Compounds
F. Xie, Z. Zhang, X. Yu, G. Tang,
X. Li*
&&&& — &&&&
À
À
À
Diaryliodoniums by Rhodium(III)-
Bonds aplenty: Diaryliodonium salts were
synthesized for the first time from elec-
tron-poor arenes by the title reaction. The
diaryliodoniums can be readily function-
alized by nucleophiles with high chemo-
selectivity, thus leading to C C, C S, C
À
À
À
Catalyzed C H Activation: Mild Synthesis
N, C P, and C Br bond formation. Cp*=
C5Me5, DG=directing group, Ts=4-tol-
uenesulfonyl.
and Diversified Functionalizations
6
www.angewandte.org
ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2015, 54, 1 – 6
These are not the final page numbers!