Room-Temperature Arylation of Thiols: Breakthrough with Aryl Chlorides

Article abstract of DOI:10.1002/anie.201610414

The formation of aryl C?S bonds is an important chemical transformation because aryl sulfides are valuable building blocks for the synthesis of biologically and pharmaceutically active molecules and organic materials. Aryl sulfides have traditionally been synthesized through the transition-metal-catalyzed cross-coupling of aryl halides with thiols. However, the aryl halides used are usually bromides and iodides; readily available, low-cost aryl chlorides often not reactive enough. Furthermore, the deactivation of transition-metal catalysts by thiols has forced chemists to use high catalyst loadings, specially designed ligands, high temperatures, and/or strong bases, thus leading to high costs and the incompatibility of some functional groups. Herein, we describe a simple and efficient visible-light photoredox arylation of thiols with aryl halides at room temperature. More importantly, various aryl chlorides are also effective arylation reagents under the present conditions.

Full text of DOI:10.1002/anie.201610414

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Communications
Chemie
International Edition: DOI: 10.1002/anie.201610414
German Edition: DOI: 10.1002/ange.201610414
Photoredox Catalysis
Room-Temperature Arylation of Thiols: Breakthrough with Aryl
Chlorides
Min Jiang, Haifang Li, Haijun Yang, and Hua Fu*
Abstract: The formation of aryl C S bonds is an important
chemical transformation because aryl sulfides are valuable
building blocks for the synthesis of biologically and pharma-
ceutically active molecules and organic materials. Aryl sulfides
have traditionally been synthesized through the transition-
metal-catalyzed cross-coupling of aryl halides with thiols.
However, the aryl halides used are usually bromides and
iodides; readily available, low-cost aryl chlorides often not
reactive enough. Furthermore, the deactivation of transition-
metal catalysts by thiols has forced chemists to use high catalyst
loadings, specially designed ligands, high temperatures, and/or
strong bases, thus leading to high costs and the incompatibility
of some functional groups. Herein, we describe a simple and
efficient visible-light photoredox arylation of thiols with aryl
halides at room temperature. More importantly, various aryl
chlorides are also effective arylation reagents under the present
conditions.
MacMillan,[6] Yoon,[7] and Stephenson[8] in 2008 and 2009,
visible-light photoredox catalysis has become a powerful
strategy, and various novel and useful reactions have been
developed under very mild conditions.[6–9] Recently, Oder-
inde, Johannes, and co-workers developed a photoredox-
mediated nickel-catalyzed cross-coupling reaction of thiols
with aryl and heteroaryl iodides via thiyl radicals.[10a] How-
ever, more readily available and inexpensive chlorides and
bromides were not effective substrates. The photoredox
synthesis of aryl sulfides from arenediazonium salts has also
recently been developed.[10b,c] As part of our continuing study
on visible-light photoredox catalysis,[11] we report herein
a general and efficient visible-light photoredox arylation of
thiols with various aryl halides, including iodides, bromides,
chlorides, and fluorides at room temperature, and the
corresponding mechanism is explored.
À
We selected the visible-light photoredox arylation of
thiophenol (2a) with methyl 4-iodobenzoate (1m) as the
model reaction to optimize the conditions, including the
photocatalyst, base, atmosphere, and reaction time. Three
bases were screened with [fac-Ir(ppy)3] (A) as the photo-
catalyst and N,N-dimethylformamide (DMF) as the solvent
under an argon atmosphere for 12 h (Table 1, entries 1–3),
and Cs2CO3 provided the highest yield (entry 1). Another two
photocatalysts, [Ir(ppy)2(dtbbpy)]PF6 (B; entry 4) and [Ru-
(bpy)3]Cl2 (C; entry 5), were found to be inferior to [fac-
Ir(ppy)3] (A). The reaction time could be shortened to 6 h
with no decrease in yield (Table 1, entries 6–8). When
dimethyl sulfoxide (DMSO) or MeCN was used as the
solvent, the product was formed in lower yield (entries 9 and
10). A decrease in yield was also observed when the reaction
was carried out in air (entry 11). A low yield was provided in
the absence of photocatalyst (entry 12), and no reaction
occurred without light (entry 13). The yield decreased when
the amount of Cs2CO3 was reduced from 1.5 equivalents to
1 equivalent (entry 14), and only a small amount of the target
product was observed in the absence of a base (entry 15).
When a 5 W LED was used for 12 h, 3m was formed in 91%
yield (entry 16), which indicated that the reaction occurred in
the range of visible light. A low yield was observed when
Cs2CO3 was replaced with an organic base (triethylamine,
entry 17). The yield was similar when the reaction was
performed in a water bath at 258C (entry 18).
T
he arylation of thiols has attracted much attention because
aryl sulfides are valuable intermediates in the preparation of
biologically and pharmaceutically active molecules and
organic materials.[1] Transition-metal-catalyzed cross-cou-
pling reactions of thiols with aryl halides are common
methods.[2] Unfortunately, the aryl halides used are usually
aryl bromides and iodides. Although aryl chlorides are widely
available and inexpensive, their application in transition-
metal-catalyzed coupling reactions is greatly limited by their
poor reactivity.[3] Furthermore, a high catalyst loading,
specially designed ligands, a high temperature, and/or strong
bases are often required because the strong coordination of
thiolates to transition-metal catalysts leads to catalyst deac-
tivation.[2] The high temperature and strong bases required for
these reactions limit functional-group tolerance. Other meth-
ods for the synthesis of aryl sulfides from arenediazonium
salts and aryl boronic acids have been developed.[4] One
hundred years ago, Ciamician carried out organic reactions
under irradiation with visible light.[5] However, developments
in visible-light photoredox organic reactions have been slow
because most organic molecules are not photoactive them-
selves. Since seminal studies by the research groups of
[*] M. Jiang, Dr. H. Li, Dr. H. Yang, Prof. Dr. H. Fu
Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical
Biology (Ministry of Education)
Only a trace amount of the product was observed when
the substrates in a common glass flask were irradiated with
a low-pressure mercury phosphor-coated lamp (310 nm,
100 W) for 12 h (Table 1, entry 19). To investigate whether
a trace amount of transition metals in the system were
involved in this reaction, we removed the solvent from the
mixture resulting from the reaction described in entry 7 of
Department of Chemistry, Tsinghua University
Beijing 100084 (China)
E-mail: fuhua@mail.tsinghua.edu.cn
Homepage: http://chem.tsinghua.edu.cn
Supporting information for this article can be found under:
http://dx.doi.org/10.1002/anie.201610414.
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Table 1: Optimization of the reaction conditions for the visible-light
photoredox arylation of thiophenol (2a) with methyl 4-iodobenzoate
(1m).[a]
base. We also intentionally added different transition-metal
salts (5 mol%), NiCl2, Cu(OAc)2, FeCl3, Pd(OAc)2, and
Mn(OAc)2, to the reaction system, and in each case the
reaction was performed under the same conditions as those in
entry 7 of Table 1. The results showed that the addition of the
transition-metal salts lowered the reactivity (product yield:
21% for NiCl2, 65% for Cu(OAc)2, 89% for FeCl3, 82% for
Pd(OAc)2, 57% for Mn(OAc)2). Thus, we could conclude that
the arylation of the thiol was not due to catalysis by transition-
metal-salt impurities in the reaction system.
Having optimized the reaction conditions, we investigated
the scope of the visible-light photoredox arylation of thiols
with aryl iodides and bromides (Scheme 1). Various aryl
iodides and bromides were first tested with thiophenol (2a) as
the reaction partner, and aryl iodides exhibited slightly higher
reactivity than the corresponding bromides. Electronic effects
on the aryl iodides and bromides did not lead to an obvious
difference in reactivity, but the substrates with ortho sub-
stituents gave lower yields (see 3g and 3o). The reaction of
1,3-dibromobenzene (1t) with 2a afforded the diarylation
product 3t. 4-Methylthiophenol (see 3u), 4-methoxythiophe-
nol (see 3v), 3-methoxythiophenol (see 3w), 2-methoxythio-
phenol (see 3x) and 4-(trifluoromethyl)thiophenol (see 3y)
delivered satisfactory results as arylthiolating reagents. We
attempted the S-arylation of the aliphatic thiol 1-butanethiol
with methyl 4-iodobenzoate (1m). Unfortunately, the reac-
tion provided 3z in only 52% yield. The arylation of thiols
tolerated various functional groups, including ether, ketone,
aldehyde, ester, cyan, nitro, and trifluoromethyl groups and
an N heterocycle.
From a practical viewpoint, the use of aryl chlorides is
highly desirable because they are much more inexpensive and
readily available than the corresponding iodides and bro-
mides. Next, we surveyed visible-light photoredox coupling
reactions of aryl chlorides with thiols. Aryl chlorides contain-
ing neutral and electron-donating groups gave the desired
products in moderate yields, and those containing electron-
withdrawing groups provided good to excellent yields
(Scheme 2). N-Heteroaryl chlorides were also good substrates
and afforded the corresponding products 3s and 3ad–af in
high yields. The reactions of aryl chlorides also tolerated
similar functional groups to those possible with aryl iodides
and bromides. Notably, these cross-coupling reactions pro-
ceeded well at room temperature. We believe that the present
method will find wide application in the synthesis of
biologically and pharmaceutically active molecules and
organic materials containing aryl sulfur moieties.
Entry PC Base (equiv) Solvent Atmosphere t [h] Yield [%][b]
1
2
3
4
5
6
7
8
9
10
11
12[c]
13[d]
14
15[e]
16[f]
17
18[g]
19[h]
20[i]
A
A
A
B
C
A
A
A
A
A
A
–
A
A
A
A
A
A
–
Cs2CO3 (1.5) DMF
K2CO3 (1.5) DMF
Ar
Ar
Ar
Ar
Ar
Ar
Ar
Ar
12
12
12
12
12
8
6
4
6
6
6
6
6
6
6
12
6
6
6
94
56
50
62
10
94
94
87
70
23
73
12
NR
83
12
91
11
90
trace
94
Na2CO3 (1.5) DMF
Cs2CO3 (1.5) DMF
Cs2CO3 (1.5) DMF
Cs2CO3 (1.5) DMF
Cs2CO3 (1.5) DMF
Cs2CO3 (1.5) DMF
Cs2CO3 (1.5) DMSO Ar
Cs2CO3 (1.5) MeCN
Cs2CO3 (1.5) DMF
Cs2CO3 (1.5) DMF
Cs2CO3 (0.5) DMF
Cs2CO3 (1.0) DMF
Ar
air
Ar
Ar
Ar
Ar
Ar
Ar
Ar
Ar
Ar
–
DMF
Cs2CO3 (1.5) DMF
NEt3 (1.5) DMF
Cs2CO3 (1.5) DMF
Cs2CO3 (1.5) DMF
Cs2CO3 (1.5) DMF
A
6
[a] Reaction conditions: Ar atmosphere (in a sealed Schlenk tube) and
irradiation with visible light from a 23 W compact fluorescent lamp
(CFL), methyl 4-iodobenzoate (1m; 0.2 mmol), thiophenol (2a;
0.3 mmol), photocatalyst (2.0 mmol), base (0.2 or 0.3 mmol), solvent
(2.0 mL), room temperature (ca. 258C; the temperature was almost
constant because the reaction was carried out under a fume hood with
a fast stream of air). [b] Yield of the isolated product. [c] The reaction was
carried out without a photocatalyst. [d] The reaction was carried out in
the dark. [e] No base was added. [f] A 5 W blue LED was used. [g] The
reaction was performed in a water bath at 258C. [h] The reaction mixture
in a common glass flask was irradiated with 100 W UV light
(l=310 nm). [i] Highly pure Cs2CO3 (99.995% purity) was used as the
base. LED=light-emitting diode, PC=photocatalyst, NR=no reaction.
We extended the visible-light photoredox arylation of
thiols to aryl fluoride substrates. Several aryl fluorides
containing electron-withdrawing groups were tested with 4-
methoxythiolphenol as the coupling partner (see 3al–ap in
Scheme 2), and they provided the corresponding target
products in good yields.
To explore the mechanism for the visible-light photoredox
arylation of thiols, we carried out some control experiments.
The treatment of (2-chlorophenyl)(phenyl)methanone (4)
with thiophenol (2a) under the standard reaction conditions
provided the direct S-arylation product 5 without the cyclic
product 6 (Scheme 3a), which implied that no free aryl radical
Table 1 with a rotary evaporator and examined the residue by
ICP mass spectrometry. Ru, Rh, Ni, Cu, Fe, Pd, Pt, Co, and
Mn were hardly observed at all (data determined by ICP mass
spectrometry: Ru: < 0.5 ppm, Rh: < 0.5 ppm, Ni: 2.86 ppm,
Cu: < 0.05 ppm, Fe: < 0.5 ppm, Pd: < 0.5 ppm, Pt: < 0.5 ppm,
Co: < 0.5 ppm, Mn: < 0.05 ppm). We attempted the reaction
with highly pure Cs2CO3 (99.995% purity, Alfa Aesar)[12] and
obtained the product in 94% yield (entry 20); thus no
difference was observed between the reactions with analyti-
cally pure (99%) and highly pure (99.995%) Cs2CO3 as the
2
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demonstrated that no aryl
carbon-centered radical (ArC)
was generated.
We investigated the kinds of
radicals produced during the
reaction by electron spin reso-
nance (ESR) spectroscopy.
Argon was bubbled into a mix-
ture of [fac-Ir(ppy)3] (A;
1 mol%),
thiophenol
(2a,
10 mm), 5,5-dimethyl-1-pyrro-
line N-oxide (DMPO; 50 mm)
as the radical trapper, and
Cs2CO3 (10 mm) in DMF for
over 20 min, and then a small
amount of the mixture was
transferred to a capillary under
argon, and ESR spectra of the
mixture were recorded under
different conditions. No radical
signal was observed without irra-
diation with visible light (Fig-
ure 1i); in contrast,
a sextet
signal with a g value of 2.006
(AN = 1.35 mT, AH = 1.47 mT)
was observed under irradiation
with visible light, which indi-
cated that a sulfur-centered rad-
ical was produced (Figure 1ii).[13]
A mixture of [fac-Ir(ppy)3] (A;
1 mol%), 4-chlorobenzonitrile
(1p; 10 mm), thiophenol (2a;
10 mm), Cs2CO3 (10 mm), and
DMPO (50 mm) in DMF was
also studied by ESR spectrosco-
py. Again, no radical signal was
observed without irradiation
with visible light (Figure 1iii);
however, besides the sextet
observed under irradiation with
visible light, we also observed
a
single-peak signal with
Scheme 1. Visible-light photoredox arylation of thiols with aryl iodides and bromides. Reaction
conditions: Ar atmosphere (sealed Schlenk tube), visible-light irradiation with a 23 W CFL, [fac-Ir(ppy)3]
(A; 2.0 mmol), aryl iodide or bromide 1 (0.2 mmol), thiol 2 (0.3 mmol), Cs2CO3 (0.3 mmol), DMF
(2.0 mL), room temperature (ca. 258C; see Table 1), 6 or 9 h. Yields are for the isolated product. [a] The
reaction was carried out with 0.6 mmol of thiophenol (2a) when 1,3-dibromobenzene (1t) was used as
the substrate.
a g value of 2.004 that could
correspond to another sulfur-
centered radical (Figure 1iv).[14]
During irradiation with visible
light, the sextet and single-peak
signals gradually decreased over
5 min (see Figures S1–S4 in the
(ArC) was formed during the reaction. The treatment of 4-
chlorobenzonitrile (1p; 0.2 mmol) with 2c (0.2 mmol) in the
presence of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO;
2 equiv) provided the product 7, resulting from trapping of
the sulfur radical derived from 2c by TEMPO, and only trace
amount of 3ah appeared, and no 4-(2,2,6,6-tetramethylpiper-
idin-1-yloxy)benzonitrile (8) was observed (Scheme 3b). The
treatment of 1p with 2c and diphenyl disulfide under the
standard conditions only provided 3ah without the formation
of 3p (Scheme 3c). The results of these two experiments also
Supporting Information), but no aryl carbon-centered radical
(ArC) with AH > 2.0 mT was found.
On the basis of the mechanistic experiments described
above, we propose the following mechanism for the visible-
light photoredox arylation of thiols (Scheme 4): The treat-
ment of an aryl thiol 2 with Cs2CO3 yields the corresponding
thiolate (Ar2SÀ Cs+). Visible-light irradiation of the photo-
catalyst IrIII affords an excited state *IrIII. Single-electron-
transfer (SET) oxidation of the Ar2SÀ anion (for example,
E1/2ox =+ 0.95 V versus the saturated calomel electrode (SCE)
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Scheme 2. Visible-light photoredox arylation of thiols with aryl chlorides and fluorides. Reaction conditions: Ar atmosphere (sealed Schlenk tube),
visible-light irradiation with a 23 W CFL, [fac-Ir(ppy)3] (A; 2.0 mmol), aryl chloride or fluoride 1 (0.2 mmol), thiol 2 (0.3 mmol), Cs2CO3 (0.3 mmol),
DMF (2.0 mL), room temperature (ca. 258C; see Table 1), 12 or 24 h. Yields are for the isolated product.
in MeCN for thiophenol)[15] by the oxidizing photoexcited
fer from III to Ar2SC affords the target product 3 and releases
the Ar2SÀ anion.
*IrIII (E1/2 [*IrIII/IrII] =+ 1.21 V versus SCE in MeCN)[9a]
red
provides both the sulfur-centered radical I and IrII. The
reduction of Ar1X (1) by IrII gives radical anion II[16] and
regenerates the photocatalyst IrIII. To further verify this
process, we used cyclic voltammetry to probe the redox
properties of IrIII/IrII and PhCl/PhCÀCl (see Figures S8 and S9).
The overlap in the potential range of the oxidation signal of
IrIII/IrII (from À1.55 to À0.78 V) and the reduction signal of
PhCl/PhCÀCl (from À1.27 to À2.22 V) indicates that the
process is thermodynamically feasible. The similar reduction
In summary, we have developed a general and efficient
visible-light photoredox arylation of thiols with aryl halides at
room temperature. The method uses readily available aryl
halides, including aryl iodides, bromides, chlorides, and
fluorides, as the arylating reagents, and exhibits broad
tolerance of functional groups. The mechanism of the
visible-light photoredox arylation was investigated. More
importantly, various aryl chlorides were also effective at room
temperature. We believe that the present discovery will be
helpful for the development of novel reactions of aryl halides,
especially chlorides, under mild conditions.
À
II
À
of Ar Cl to the radical anion ArC Cl by Ir in the presence of
diisopropylethylamine (DIPEA) was reported by Senaweera
and Weaver.[16c] The Ar2SÀ anion reacts with II to give the
sulfur-centered radical anion III,[14a] and single-electron trans-
4
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Scheme 3. Investigation of the mechanism of the visible-light photoredox arylation of thiols. Reaction conditions: a) standard conditions; b) 1p
(0.2 mmol), 2a (0.2 mmol), TEMPO (2 equiv, 0.4 mmol); c) 1p (0.2 mmol), 2c (0.2 mmol), diphenyl disulfide (0.2 mmol).
Figure 1. ESR spectra under different conditions: i) ESR spectrum for
a mixture of [fac-Ir(ppy)3] (1 mol%), 2a (10 mm), DMPO (50 mm), and
Scheme 4. Proposed mechanism for the visible-light photoredox aryla-
tion of thiols.
Cs2CO3 (10 mm) in DMF without irradiation with visible light; ii) ESR
spectrum for a mixture of [fac-Ir(ppy)3] (1 mol%), 2a (10 mm), DMPO
(50 mm), and Cs2CO3 (10 mm) in DMF under irradiation with visible
light for 30 s; iii) ESR spectrum for a mixture of [fac-Ir(ppy)3]
(1 mol%), 1p (10 mm), 2a (10 mm), DMPO (50 mm), and Cs2CO3
(10 mm) in DMF without irradiation with visible light; iv) ESR spec-
trum for a mixture of [fac-Ir(ppy)3] (1 mol%), 1p (10 mm), 2a
(10 mm), DMPO (50 mm), and Cs2CO3 (10 mm) in DMF under
irradiation with visible light for 30 s.
Conflict of interest
The authors declare no conflict of interest.
À
Keywords: arylation · C S coupling · photocatalysis ·
synthetic methods · thiols
Acknowledgements
Financial support for this research was provided by the
National Natural Science Foundation of China (Grant No.
21372139).
[1] a) P. Metzner, A. Thuillier, Sulfur Reagents in Organic Synthesis
(Eds.: A. R. Katritzky, O. Meth-Cohn, C. W. Rees), Academic
Press, San Diego, CA, 1994; b) B. M. Trost, I. Fleming,
Comprehensive Organic Synthesis, Vol. 6, Pergamon, New
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Communications
Chemie
York, 1991; c) Z. Y. Sun, E. Botros, A. D. Su, Y. Kim, E. J. Wang,
N. Z. Baturay, C. H. Kwon, J. Med. Chem. 2000, 43, 4160 – 4168;
d) A. Gangjee, Y. B. Zeng, T. Talreja, J. J. McGuire, R. L.
Kisliuk, S. F. Queener, J. Med. Chem. 2007, 50, 3046 – 3053; e) B.
Le Grand, C. Pignier, R. Lꢀtienne, F. Cuisiat, F. Rolland, A. Mas,
B. Vacher, J. Med. Chem. 2008, 51, 3856 – 3866.
Chem. 2009, 121, 9969 – 9974; f) J. Xuan, W.-J. Xiao, Angew.
Chem. Int. Ed. 2012, 51, 6828 – 6838; Angew. Chem. 2012, 124,
6934 – 6944; g) L. Shi, W. Xia, Chem. Soc. Rev. 2012, 41, 7687 –
7697; h) D. P. Hari, B. Kçnig, Angew. Chem. Int. Ed. 2013, 52,
4734 – 4743; Angew. Chem. 2013, 125, 4832 – 4842; i) Y. Xi, H. Yi,
A. Lei, Org. Biomol. Chem. 2013, 11, 2387 – 2403.
[2] a) I. P. Beletskaya, V. P. Ananikov, Chem. Rev. 2011, 111, 1596 –
1636; b) M. Murata, S. L. Buchwald, Tetrahedron 2004, 60, 7397 –
7403; c) F. Y. Kwong, S. L. Buchwald, Org. Lett. 2002, 4, 3517 –
3520; d) J. F. Hartwig, Acc. Chem. Res. 2008, 41, 1534 – 1544;
e) M. A. Fernꢁndez-Rodrꢂguez, Q. Shen, J. F. Hartwig, J. Am.
Chem. Soc. 2006, 128, 2180 – 2181; f) E. Alvaro, J. F. Hartwig, J.
Am. Chem. Soc. 2009, 131, 7858 – 7868; g) C. Uyeda, Y. Tan,
G. C. Fu, J. C. Peters, J. Am. Chem. Soc. 2013, 135, 9548 – 9552;
h) M. Sayah, M. G. Organ, Chem. Eur. J. 2011, 17, 11719 – 11722;
i) P. Gogoi, S. Hazarika, M. J. Sarma, K. Sarma, P. Barman,
Tetrahedron 2014, 70, 7484 – 7489.
[3] a) A. F. Littke, G. C. Fu, Angew. Chem. Int. Ed. 2002, 41, 4176 –
4211; Angew. Chem. 2002, 114, 4350 – 4386; b) J. L. Farmer, M.
Pompeo, A. J. Lough, M. G. Organ, Chem. Eur. J. 2014, 20,
15790 – 15798; c) V. Dichiarante, M. Fagnoni, A. Albini, Chem.
Commun. 2006, 3001 – 3003; d) M. Bergami, S. Protti, D. Ravelli,
M. Fagnoni, Adv. Synth. Catal. 2016, 358, 1164 – 1172.
[4] a) N. Mukherjee, T. Chatterjee, B. C. Ranu, J. Org. Chem. 2013,
78, 11110 – 11114; b) G. Petrillo, M. Novi, G. Garbarino, D.
Carlo, Tetrahedron 1986, 42, 4007 – 4016; c) H.-J. Xu, Y.-Q.
Zhao, T. Feng, Y.-S. Feng, J. Org. Chem. 2012, 77, 2878 – 2884.
[5] G. Ciamician, Science 1912, 36, 385 – 394.
[6] D. A. Nicewicz, D. W. C. MacMillan, Science 2008, 322, 77 – 80.
[7] M. A. Ischay, M. E. Anzovino, J. Du, T. P. Yoon, J. Am. Chem.
Soc. 2008, 130, 12886 – 12887.
[10] a) M. S. Oderinde, M. Frenette, D. W. Robbins, B. Aquila, J. W.
Johannes, J. Am. Chem. Soc. 2016, 138, 1760 – 1763; b) X. Wang,
G. D. Cuny, T. Noꢃl, Angew. Chem. Int. Ed. 2013, 52, 7860 – 7864;
Angew. Chem. 2013, 125, 8014 – 8018; c) M. Majekz, A. Jacobi
von Wangelin, Chem. Commun. 2013, 49, 5507 – 5509.
[11] a) M. Jiang, Y. Jin, H. Yang, H. Fu, Sci. Rep. 2016, 6, 26161; b) Y.
Jin, M. Jiang, H. Wang, H. Fu, Sci. Rep. 2016, 6, 20048; c) C. Gao,
J. Li, J. Yu, H. Yang, H. Fu, Chem. Commun. 2016, 52, 7292 –
7294; d) J. Li, H. Tian, M. Jiang, H. Yang, Y. Zhao, H. Fu, Chem.
Commun. 2016, 52, 8862 – 8864; e) M. Jiang, H. Yang, H. Fu,
Org. Lett. 2016, 18, 1968 – 1971; f) M. Jiang, H. Yang, H. Fu, Org.
Lett. 2016, 18, 5248 – 52511; g) Y. Jin, H. Yang, H. Fu, Chem.
Commun. 2016, 52, 12909 – 12912.
[12] The following data were provided by the company Alfa Aesar:
Cs2CO3: 99.995%, other impurities: 0.005% (total trace metal
impurities: < 0.0008%).
[13] M. J. Davies, L. G. Forni, S. L. Shuter, Chem.-Biol. Interact. 1987,
61, 177 – 188.
[14] a) F. Trompier, A. Romanyukha, R. Reyes, H. Vezin, F.
Queinnec, D. Gourier, Radiat. Environ. Biophys. 2014, 53,
291 – 303; b) F. Gerson, W. Huber, Electron Spin Resonance
Spectroscopy of Organic Radicals, Wiley-VCH, Weinheim, 2003.
[15] a) F. G. Bordwell, X.-M. Zhang, A. V. Satish, J.-P. Cheng, J. Am.
Chem. Soc. 1994, 116, 6605 – 6610; b) M. Kuss-Petermann, O. S.
Wenger, J. Phys. Chem. Lett. 2013, 4, 2535 – 2539.
[8] J. M. R. Narayanam, J. W. Tucker, C. R. J. Stephenson, J. Am.
Chem. Soc. 2009, 131, 8756 – 8757.
[16] a) I. Ghosh, T. Ghosh, J. I. Bardagi, B. Kçnig, Science 2014, 346,
725 – 728; b) S. M. Senaweera, A. Singh, J. D. Weaver, J. Am.
Chem. Soc. 2014, 136, 3002 – 3005; c) S. Senaweera, J. D. Weaver,
J. Am. Chem. Soc. 2016, 138, 2520 – 2523.
[9] a) C. K. Prier, D. A. Rankic, D. W. C. MacMillan, Chem. Rev.
2013, 113, 5322 – 5363; b) Chemical Photocatalysis (Ed.: B.
Kçnig), De Gruyter, Stuttgart, 2013; c) J. M. R. Narayanam,
C. R. J. Stephenson, Chem. Soc. Rev. 2011, 40, 102 – 113; d) T. P.
Yoon, M. A. Ischay, J. Du, Nat. Chem. 2010, 2, 527 – 532; e) K.
Zeitler, Angew. Chem. Int. Ed. 2009, 48, 9785 – 9789; Angew.
Manuscript received: October 24, 2016
Final Article published: && &&, &&&&
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ꢀ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2016, 55, 1 – 7
These are not the final page numbers!

Angewandte
Communications
Chemie
Communications
Photoredox Catalysis
M. Jiang, H. Li, H. Yang,
H. Fu*
&&&& — &&&&
Room-Temperature Arylation of Thiols:
Breakthrough with Aryl Chlorides
All clear for chlorides: In a general and
efficient visible-light photoredox arylation
of thiols with aryl halides at room tem-
perature, various aryl chlorides were also
effective arylation reagents (see scheme).
The successful use of these readily avail-
able, inexpensive substrates may inspire
the development of similar strategies for
other valuable chemical transformations.
Angew. Chem. Int. Ed. 2016, 55, 1 – 7
ꢀ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
7
These are not the final page numbers!