Cuprous cluster as effective single-molecule metallaphotocatalyst in white light-driven C[sbnd]H arylation

Article abstract of DOI:10.1016/j.jcat.2019.08.017

This study investigated a series of ferrocenyltelluroether based cuprous halide clusters as effective single-molecule metallaphotocatalysts (SMP) in white light-driven C[sbnd]H arylation at room temperature and air. A systematic mechanistic study reveals that Cu(I) cluster can be irradiated by visible light to promote proton-coupled electron transfer (PCET), during which the electron from Cu(I)* leaves together with the proton from benzothiazole C[sbnd]H, leading to the formation of benzothiazolate-coordinated Cu(II) intermediate and aryl radical. Subsequently, the electron transfer (ET) from the ferrocene unit to the Cu(II) center releases the reactive benzothiazolate to form the target product with aryl radical. The advantages of these copper(I) halide clusters as SMP include high photocatalytic efficiency, structure adjustability, mild reaction conditions and good functional group tolerance.

Full text of DOI:10.1016/j.jcat.2019.08.017

Journal of Catalysis 378 (2019) 270–276
Contents lists available at ScienceDirect
Journal of Catalysis
journal homepage: www.elsevier.com/locate/jcat
Research Note
Cuprous cluster as effective single-molecule metallaphotocatalyst in
white light-driven CAH arylation
Wei Ji a,1, Hao Wang , Cheng-An Li , Fei Gao , Zhong-Fu An , Ling Huang , He Wang , Yue Pan ,
b,1
a,1
c
d
d
d
d
e
a
a
f
a,
⇑
Dun-Ru Zhu , Jian-Qiang Wang , Cheng Guo , José A. Mayoral , Su Jing
School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
Institute of Advanced Synthesis, Nanjing Tech University, Nanjing 211816, China
Jiangsu Key Laboratory of Vehicle Emissions Control Center of Modern Analysis, Nanjing University, Nanjing 210093, China
Institute of Advanced Materials, Nanjing Tech University, Nanjing 210009, China
a
b
c
d
e
f
College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
Instituto de Síntesis Química y Catálisis Homogénea, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, E-50009 Zaragoza, Spain
a r t i c l e i n f o
a b s t r a c t
Article history:
This study investigated a series of ferrocenyltelluroether based cuprous halide clusters as effective single-
molecule metallaphotocatalysts (SMP) in white light-driven CAH arylation at room temperature and air.
A systematic mechanistic study reveals that Cu(I) cluster can be irradiated by visible light to promote
proton-coupled electron transfer (PCET), during which the electron from Cu(I)* leaves together with
the proton from benzothiazole CAH, leading to the formation of benzothiazolate-coordinated Cu(II) inter-
mediate and aryl radical. Subsequently, the electron transfer (ET) from the ferrocene unit to the Cu(II)
center releases the reactive benzothiazolate to form the target product with aryl radical. The advantages
of these copper(I) halide clusters as SMP include high photocatalytic efficiency, structure adjustability,
mild reaction conditions and good functional group tolerance.
Received 7 July 2019
Revised 17 August 2019
Accepted 17 August 2019
Keywords:
Metallaphotocatalyst
Copper(I) halide cluster
Ferrocenyltelluroether
White light
Ó 2019 Elsevier Inc. All rights reserved.
CAH activation
1
. Introduction
Cuꢀ ꢀ ꢀIr MP [12–15]. Incorporating the hydrogen atom transfer
(
HAT) mode with Niꢀ ꢀ ꢀIr MP, MacMillan developed a ternary cat-
3
Enormous efforts have been paid to efficient CAH arylation due
alytic system that enables the selective arylation of sp CAH bonds
to its significance in chemical synthesis, pharmaceutics and mate-
rial fields [1–4]. To develop novel, economical and highly efficient
strategies for different types of CAH arylation under mild condi-
tions remains a very challenging subject. One approach that has
received much attention recently is the synergistic combination
of transition metal catalysis and photocatalysis, termed metal-
laphotocatalysis (MP). In MP platform, with suitable light irradia-
tion, photocatalyst can produce powerful driving force, which
effectively activates transition metal catalysts for direct coupling
of non-traditional nucleophile partners. The MP platform can per-
form well under the milder reaction conditions, with the advan-
tages such as visible-light irradiation, air, absence of high
temperature and external strong oxidants (Fig. 1) [5–10].
[16]. Doyle reported that halogen radicals can function as HAT
reagents for Niꢀ ꢀ ꢀIr MP-mediated
a oxy CAH arylation [17]. Lee
found Auꢀ ꢀ ꢀRu MP conferred regioselectivity via the crucial Au-
catalyzed CAH activation step [18]. In all these aforementioned
dual MP systems, the excited state of the photocatalysts must live
long enough to encounter transition metal catalysts and/or sub-
strates before undergoing deactivation. So the expensive ruthe-
nium or iridium complexes, are pre-requisite photocatalysts due
to their strong absorption in visible light region and sufficient long
excited state lifetimes. The quest to culminate atom-economical
photocatalytic methods is then the driving force to explore SMP,
which bears ‘double duty’ in harvesting visible light and enabling
catalysis via unimolecular. As an emerging area, to construct effec-
tive visible light promoted SMPs in CAH arylation and to elucidate
the operative mode of activation will provide strong support to the
development of valuable transformations of organic molecules.
Copper complexes in catalytic processes have been actively
explored owing to their diverse structures with oriented electron
transfer properties and rich photoexcited states [19–22]. Recently,
Peters has achieved the NAC, SAC, OAC and CAC coupling of
The Pdꢀ ꢀ ꢀRu MP platform for CAH arylation with visible light at
room temperature was first reported by Sanford in 2011 [11]. Ack-
ermann accomplished the photoinduced CAH arylation with
⇑
Corresponding author.
E-mail address: sjing@njtech.edu.cn (S. Jing).
W. J., H. W. and C.-A. L. contributed equally to this work.
1
https://doi.org/10.1016/j.jcat.2019.08.017
021-9517/Ó 2019 Elsevier Inc. All rights reserved.
0

W. Ji et al. / Journal of Catalysis 378 (2019) 270–276
271
air-stable copper-phenylacetylide coordination polymer can be
used in effective elimination of organic pollutants under visible
light irradiation [27]. Overall, polynuclear copper(I) halide clusters
(
n n
Cu X ) have shown great potential application in the lumines-
cence and catalysis field [28–30]. Considering the fact that stable
copper(I) complexes can be constructed with soft Se or Te donor
atoms, our group has embarked on the systematic study of Cu
clusters based upon neutral ferrocenylchalcogenoethers, FcCu
n
X
X
n
n
n
(
Fc = ferrocenyl) [31,32]. In the previous study, we found that these
FcCu showed excellent catalytic activities in C-N coupling reac-
n n
X
tion of imidazole with iodobenzene under mild condition [31,32].
A concerted PCET process from the Cu(I) center and substrate facil-
itates the formation of Cu(II) intermediate. The different coordina-
tion mode of Cu(I)/Cu(II), together with the redox ferrocene unit,
lead to the formation of the target product. Furthermore, we suc-
Fig. 1. Light-driven CAH arylation with MP and SMP (Het = Heterocycle).
2 2 2 2 n
cessfully constructed the core-shell TiO @[Cu I L ] material
heterocycle with organic halides under blue light irradiation and
mild conditions, in which, the in situ generated copper complex
was proposed as photocatalyst [23–25]. Hwang reported that
Sonogashira reaction can operate under irradiation of visible light
with low loading of CuCl catalysts [26]. Due to the adjustable com-
positions and designable architecture networks, copper-based
coordination polymers have been developed as a new member of
photocatalytic materials. Song demonstrated that the nanobelt of
which shows an effective visible-light photocatalytic property in
the reduction of aqueous chromium(VI) [33]. The excited [Cu I L ]
2
2 2 n
under visible light illumination generated electrons, which can
be transferred into the conduction band of TiO2 for the reduction
of chromium (VI) species. With these in mind, combining the pro-
gress in CAH activation with copper-containing catalysts, we are
now exploring a protocol for visible light-mediated CAH arylation
using FcCu X clusters as the possible SMP candidates (Fig. 1).
n
n
Scheme 1. Molecular structures of clusters 1–8.

2
72
W. Ji et al. / Journal of Catalysis 378 (2019) 270–276
2
. Materials and methods
2.2. Characterization
1H NMR spectra were recorded on a Bruker DRX spectrometer
400 MHz) at ambient temperature and the chemical shifts were
referenced to the solvent signal in CDCl . X-ray photoelectron spec-
2
.1. Reagents
(
0
Ferrocene, tellurium, dibromopropane,
a
,a
-dibromo-p-xylene,
3
0
a
1
4
3
,a
-dibromo-m-xylene, benzothiazole, benzoxazole, iodobenzene,
troscopy (XPS) with PHI 5000 VersaProbe of UIVAC-PHI and all
binding energies were referenced to the C1s peak at 284.8 eV.
The solution electron paramagnetic resonance (EPR) spectrum
was obtained using Bruker EMX plus-6/1 X-band variable-
temperature apparatus. Fourier transform infrared spectroscopy
-iodo-4-methylbenzene, 1-iodo-4-methoxybenzene, 1-iodo-
-chlorobenzene, 1-iodo-4-(trifluoromethyl)benzene, 1-iodo-
-methylbenzene, 1-iodo-3-methoxybenzene, 1-iodo-3-chloro-
benzene, 1-iodo-3-(trifluoromethyl)benzene, lithium tert-butoxide
and CuX (X = Br or I) are of AR grade. Copper clusters 1–8 were pre-
pared according to our reported methods [31,32]. All solvents used
were purified following standard procedures prior to use.
ꢁ1
(FTIR) was recorded within the 400–4000 cm region on a Thermo
Scientific Nicolet IS10 FTIR spectrometer using KBr pellets. UV–vis
diffuse reflectance spectra (UV–vis DRS) were recorded using
Table 1
Model photo-assisted CAH arylation using copper clusters 1–8.a
Entry
Catalyst
Solvent
Yield [%]b
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
1
1
1
1
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
THF
86
61
63
73
60
70
64
40
42
trace
59
23
70
56
0
10
11
12
13
14
15
16
17
18
2
H O
MeCN
Et
2
O
1
DMF
c
CuI (20% mol) + free ligand in 1
CuI (20% mol)
None
1 (dark)
1
DMSO
DMSO
DMSO
DMSO
DMSO
0
0
52
d
a
b
c
Model reaction condition: iodobenzene (1.25 mmol), benzothiazole (0.25 mmol), copper cluster (20 mol% Cu), t-BuOLi (0.75 mmol), solvent (2.0 mL).
Isolated yield of target product.
Free ligand in 1 is diferrocenyl ditelluride.
d
Only changing the ratio of substrates: iodobenzene (0.25 mmol), benzothiazole (0.25 mmol).
Scheme 2. The scopes of azole and iodobenzene in the CAH arylation with model reaction condition: iodobenzene (1.25 mmol), azole (0.25 mmol), cluster 1 (20 mol% Cu), t-
BuOLi (0.75 mmol), DMSO (2.0 mL).

W. Ji et al. / Journal of Catalysis 378 (2019) 270–276
273
PerkinElmer Lambda 950 UV/Vis/NIR Spectrophotometer, with
BaSO as the reference. UV–vis absorption spectra were measured
with Hitachi spectrophotometer UV-3900. Steady state photolumi-
nescence emission spectra were measured with Horiba Jobin Yvon
FluoroMax-4 and the fluorescence photos of samples were taken
with Hitachi fluorescence spectrophotometer F-7000. Fluorescence
decay and time-resolved emission spectra were recorded using an
Edinburgh FLSP920 fluorescence spectrophotometer equipped
with tunable bonds of laser from 400 nm to 500 nm. GC experi-
ments were performed on an Agilent 7890B gas chromatograph
4
equipped with a 30 m ꢂ 0.32 mm ꢂ 0.25
lm HP-5 capillary col-
umn and a FID detector.
Fig. 2. Proposed mechanism.
Fig. 3. (a) UV–Vis spectra of 1 and 1i suspension in DMSO solution; (b) UV–vis DRS spectra of solid 1 and 1i.

2
74
W. Ji et al. / Journal of Catalysis 378 (2019) 270–276
2.3. Evaluation of catalytic activity
tive TLC (EtOAc:n-hexane = 1:20 (v/v)) to afford the desired
product.
All reagents were weighed and handled in air at room temper-
ature. For the studies of catalytic activity reactions, a White-LED
2
with the power density of 300 mW/cm , was employed as the light
3. Results and discussion
source. A general procedure: heterocycle substrate (0.25 mmol),
aryl halide (1.25 mmol), copper(I) cluster (20 mol%), t-BuOLi
3.1. Investigation of initial optimization and substrate scopes
(
1
0.75 mmol), and DMSO (2.0 mL) were placed in a pre-dried
0 mL quartz tube. The tube was opened to air and the resulting
We initiated the catalytic studies by probing the photo-assisted
CAH arylation of benzothiazole with iodobenzene. Eight ferro-
cenyltelluroethers FcCu X , 1–8 (Scheme 1), were chosen for the
reaction mixture was stirred for 16 h under white light irradiation
at ambient temperature. Next, the crude reaction mixture was
n
n
diluted with 20 mL H
solvent of the combined organic phases was removed under
reduced pressure. The resulting residue was purified by prepara-
2
O and extracted with 3 ꢂ 20 mL EtOAc. The
screening as SMP candidates. The model reactions were performed
using copper cluster with 20 mol% Cu as the SMP, 5 equiv. of
iodobenzene and 3 equiv. of base relative to the amount of
Fig. 4. XPS spectra of (a) 1 and 1i; (b) Cu2p in 1; (c) Cu2p in 1i; (d) Te3d in 1 and 1i; (e) S2p in 1i; and (f) N1s in 1i.
Fig. 5. (a) Fluorescence spectra of 1 and 1i in DMSO excited at 459 nm; (b) Fluorescence lifetime decay profiles of fluorescence emission bands of 1, and 1i excited in the
region of 400–500 nm.

W. Ji et al. / Journal of Catalysis 378 (2019) 270–276
275
7
ꢁ1
ꢁ1
benzothiazole at room temperature, air and DMSO solvent. Product
N-(4-phenyl)benzothiazole in isolated yield was shown in Table 1.
While different SMPs provided comparable results (Table 1, entries
two absorption bands at 394 nm (
e
= 5.30 ꢂ 10
M
m
) and
7
ꢁ1
ꢁ1
465 nm (
e
= 3.74 ꢂ 10
M
m ), which nicely overlap with the
emission band of the white light used for the catalytic reactions
(Fig. 3a). It was found that when benzothiazole and t-BuOLi were
added into the solution of 1, a yellow green mixture appeared
under white light, which can be ascribed to the formation of the
1
–8), the best performance was obtained with cluster 1 which gave
the target product in 86% yield. A reaction conducted in other reac-
tion media, including THF, H O, MeCN, Et O and DMF, proceeded
2
2
+
less efficiently (Table 1, entries 9–13). The catalytic activity of
CuI and free ligand diferrocenyl ditelluride (Table 1, entry 14)
was much worse than that of cluster 1, and no product was
observed if only CuI was used (Table 1, entry 15). The CAH aryla-
tion did not occur in the absence of SMP or in the dark (Table 1,
entries 16 and 17). Changing the molar ratio of iodobenzene and
benzothiazole to 1:1, the target product is obtained in lower yield
Fc . Diethyl ether was then added into solution to precipitate the
intermediate product, 1i. In the UV–vis DRS spectra of 1 and 1i
(Fig. 3b), the strong and broad visible absorption band in the region
of 380–650 nm suggests that 1 can behave as efficient photocata-
lyst candidate in visible light-driven reaction. This is in accordance
with the result that the catalytic activity of CuI and free ligand
(Table 1, entry 14) was much worse than that of cluster 1.
(
(
52%) (Table 1, entry 18) than that using 5 equiv. of iodobenzene
86%) (Table 1, entry 1). The scopes of the substrates in the
Secondly, X-ray photoelectron spectra (XPS) in Fig. 4 indicates
the coexistence of Cu(I) and Cu(II) in 1i. The main peak of Cu
2p3/2 at 933.0 eV and the satellite peak at 942.5 eV in 1i verify that
most of Cu centers are in +2 state (Fig. 4a–c). The weak peak at
931.7 eV and the ratio of intensity of the satellite peak to that of
the main peak (Isat/Imain = 0.77) in 1i can be ascribed to the exis-
tence of Cu(I) [38,39]. When a solution of 1, benzothiazole and t-
BuOLi is irradiated under the model condition by visible light at
room temperature, a weak EPR signal is observed which can be
tentatively ascribed to the Cu(II) in 1i (Fig. S12) [25]. The XPS
bands of Te 3d, S 2p and N 1 s shown in Fig. 4d–f, respectively, sup-
ports the coordination of benzothiazolate to Cu center in 1i, which
photo-assisted CAH arylation were then explored by probing
different substituted azole to react with iodobenzene (Scheme 2).
Cluster 1 was proved to have good functional group tolerance to
deliver the desired CAH arylation products (Figs. S1–S11).
3
.2. Mechanism study
As shown in Fig. 2, the proposed mechanism includes five steps:
(
i) Cu(I) center is irradiated by visible light to obtain the excited
state Cu(I)*; (ii) The photo promoted PCET is then progressed
34–37], in which the electron from Cu(I)* coupling the proton
from benzothiazole CAH leads to penta-coordinated Cu(II) com-
[
was also confirmed by FTIR (Fig. S13). The mC–H peak of free ben-
ꢁ
1
zothiazolate at 3030–3020 cm disappeared in the FTIR spectrum
ꢁ
+
ꢁ1
plex with two I , two Te atoms and one benzothiazolate. H is con-
sumed by t-BuOLi, and electron transferred to aryl halide giving
aryl radical and I ; (iii) The ET from Fc unit to the Cu(II) gives fer-
rocenium unit (Fc , the oxidized form of ferrocene) and Cu(I); (iv)
The released reactive benzothiazolate combines aryl radical to
form the product; (v) Finally the Fc was reduced by I to produce
the neutral Fc.
The proposed mechanism is supported by a series of experi-
ments. Firstly, UV–vis spectrum of cluster 1 in DMSO exhibited
of 1i. Moreover, the
m
C@N (1600–1300 cm ) and
m
C–S (780–
ꢁ1
600 cm ) of benzothiazolate are also shifted significantly due to
the formation of the intermediate 1i (Fig. S13).
ꢁ
+
Thirdly, the steady-state photoluminescence emission spec-
trum of cluster 1 under 459 nm excitation (Fig. 5a) revealed a weak
band at 535 nm, the obvious quenching effect can be ascribed to
the photoinduced electron transfer (PET) process from the fer-
rocene moiety to the excited copper center. And for 1i, the inten-
sity of photoluminescence increased significantly, indicating that
+
ꢁ
Scheme 3. Probing a radical mechanism.

2
76
W. Ji et al. / Journal of Catalysis 378 (2019) 270–276
the PET process is prohibited due to the ferrocenium unit Fc+
Fig. 5a). Then the excited-state quenching kinetics of 1 and 1i
Province (Project No. 2018011), and Natural Science Fund for
Distinguished Young Scholars of Jiangsu Province (BK20180037)
and Natural Science Foundation of Jiangsu Province (BK20181374).
(
was further investigated (Fig. 5b). A clear biexponential decay of
the emission was observed, which gives a lifetime of 3.1 ns (64%)
and 0.6 ns (36%) for 1, 1.8 ns (60%) and 0.2 ns (40%) for 1i, respec-
tively (Fig. 5b) [40]. These differences may be due to the structure
variation of the Cu cluster and the potential change of the oxida-
tion state of Fe in the ferrocene unit. The longer fluorescence life-
time separation process can be attributed to the intrinsic
fluorescence lifetime of metal cluster, while the short lifetime com-
ponent suggests the presence of the quenched fluorescence of clus-
ter center [41]. As compared to the penta-coordinate mode of Cu
Appendix A. Supplementary material
Supplementary data to this article can be found online at
https://doi.org/10.1016/j.jcat.2019.08.017.
References
[1] I.V. Seregin, V. Gevorgyan, Chem. Soc. Rev. 36 (2007) 1173–1193.
[
[
2] O. Daugulis, H.Q. Do, D. Shabashov, Acc. Chem. Res. 42 (2009) 1074–1086.
3] J. Wencel-Delord, T. Dröge, F. Liu, F. Glorius, Chem. Soc. Rev. 40 (2011) 4740–
(
II) in 1i, the more stable tetrahedral coordination geometry of
Cu(I) in 1 can protect the Cu(I) center in excited state, and elongate
the emission lifetime. Similar phenomena have been observed
before [42].
4761.
[4] P. Nareddy, F. Jordan, M. Szostak, ACS Catal. 7 (2017) 5721–5745.
[
[
5] C.K. Prier, D.A. Rankic, D.W.C. MacMillan, Chem. Rev. 113 (2013) 5322–5363.
6] M.N. Hopkinson, B. Sahoo, J.-L. Li, F. Glorius, Chem. Eur. J. 20 (2014) 3874–
Fourthly, the addition of the radical TEMPO into the catalytic
system resulted in a significant inhibition of the catalytic perfor-
mance of 1 (Scheme 3a). When 1 equiv. of TEMPO (compared to
the benzothiazole) was applied, only 32% yield of the target pro-
duct was obtained, whereas under the same conditions the target
product was 86% yield without TEMPO. When 2 equiv. of TEMPO
3
886.
[7] K.L. Skubi, T.R. Blum, T.P. Yoon, Chem. Rev. 116 (2016) 10035–10074.
[
[
8] L. Huang, M. Rudolph, F. Rominger, A.S. Hashmi, Angew. Chem. Int. Ed. 55
2016) 4808–4813.
(
9] J. Twilton, C. Le, P. Zhang, M.H. Shaw, R.W. Evans, D.W.C. MacMillan, Nat. Rev.
Chem. 1 (2017) 0052.
[
[
10] V. Gevorgyan, M. Ratushnyy, M. Parasram, Y. Wang, Angew. Chem. Int. Ed. 57
2018) 2712–2715.
(
(
compared to the benzothiazole) was used, the SMP performance
11] D. Kalyani, K.B. McMurtrey, S.R. Neufeldt, M.S. Sanford, J. Am. Chem. Soc. 133
(2011) 18566–18569.
12] F. Yang, J. Koeller, L. Ackermann, Angew. Chem. Int. Ed. 55 (2016) 4759–4762.
13] P. Gandeepan, J. Koeller, L. Ackermann, ACS Catal. 7 (2017) 1030–1034.
14] P. Gandeepan, J. Mo, L. Ackermann, Chem. Commun. 53 (2017) 5906–5909.
[15] M.M. Lorion, K. Maindan, A.R. Kapdi, L. Ackermann, Chem. Soc. Rev. 46 (2017)
7399–7420.
16] M.H. Shaw, V.W. Shurtleff, J.A. Terrett, J.D. Cuthbertson, D.W.C. MacMillan,
Science 352 (2016) 1304–1308.
17] B.J. Shields, A.G. Doyle, J. Am. Chem. Soc. 138 (2016) 12719–12722.
[18] V. Gauchot, D.R. Sutherland, A.-L. Lee, Chem. Sci. 8 (2017) 2885–2889.
19] G. Evano, N. Blanchard, M. Toumi, Chem. Rev. 108 (2008) 3054–3131.
20] A.J. Hickman, M.S. Sanford, Nature 484 (2012) 177–185.
of the cluster 1 is completely inhibited because no product can
be detected after the reaction. This phenomenon can be ascribed
to a rapid reversible PCET process between TEMPO and TEMPOH
[
[
[
(Scheme 3b), in agreement with previous observations [43].
Finally, in our proposed mechanism, the photo-promoted PCET
[
is the prerequisite step for the generation of aryl radical. So the
application of iodobenzene in excess is essentially important. In a
control experiment using benzothiazole and iodobenzene in
[
[
[
[
1
:1 molar ratio, the target product was obtained in much lower
yield of only 52% compared to 86% that using 5 equiv. of iodoben-
zene (Table 1, entry 18 vs entry 1). And no biphenyl compound was
obtained as byproduct (Fig. S14). This indicates that once the ben-
zothiazole is consumed, no aryl radical can then be generated
effectively. Due to short lifetime of aryl radicals, excess iodoben-
zene can effectively obtain electron from PCET step to form aryl
radical, then improve the yield of the target product.
21] X.-X. Guo, D.-W. Gu, Z.-X. Wu, W.-B. Zhang, Chem. Rev. 115 (2014) 1622–1651.
[22] S. Paria, O. Reiser, ChemCatChem 6 (2014) 2477–2483.
23] J. He, C.-Y. Chen, G.C. Fu, J.C. Peters, ACS Catal. 8 (2018) 11741–11748.
24] W. Zhao, R.P. Wurz, J.C. Peters, G.C. Fu, J. Am. Chem. Soc. 139 (2017) 12153–
[
[
1
2156.
[25] J.M. Ahn, T.S. Ratani, K.I. Hannoun, G.C. Fu, J.C. Peters, J. Am. Chem. Soc. 139
2017) 12716–12723.
(
[
[
26] A. Sagadevan, K.C. Hwang, Adv. Synth. Catal. 354 (2012) 3421–3427.
27] H.-Y. Jiang, P. Zhou, Y.-Y. Wang, R. Duan, C.-C. Chen, W.-J. Song, J.-C. Zhao, Adv.
Mater. 28 (2016) 9776–9781.
[
[
[
28] W. Liu, K. Zhu, S.J. Teat, G. Dey, Z.-Q. Shen, L. Wang, D.M. O’Carroll, J. Li, J. Am.
4
. Conclusions
Chem. Soc. 139 (2017) 9281–9290.
29] D.-Y. Shi, R. Zheng, M.-J. Sun, X.-R. Cao, C.-X. Sun, C.-J. Cui, C.-S. Liu, J.-W. Zhao,
M. Du, Angew. Chem. Int. Ed. 56 (2017) 14637–14641.
30] B. Huitorel, H. El Moll, R. Utrera-Melero, M. Cordier, A. Fargues, A. Garcia, F.
Massuyeau, C. Martineau-Corcos, F. Fayon, A. Rakhmatullin, S. Kahlal, J.Y.
Saillard, T. Gacoin, S. Perruchas, Inorg. Chem. 57 (2018) 4328–4339.
In summary, the ferrocenyltelluroether based copper(I) halide
clusters have been proven to be the effective SMP in white light-
driven CAH arylation of azoles. The ‘double duty’ of the copper(I)
halide clusters enables the success: (I) Ferrocenyltelluroether
based copper(I) cluster owns high visible-light activity; (II) Cop-
per(I) acts as high catalytic-active participant in the forming step
of Cu-benzothiazolate intermediate. In this catalytic cycle, PCET
process avoids the high-energy intermediate state, and redox fer-
rocene unit plays the important role of electron shuttle to stabilize
the intermediate redox products. These synergistic effects endow
ferrocenyltelluroether based copper(I) halide clusters with SMP
feature to activate the corresponding inert substrates. The present
visible-light-driven photocatalytic system opens new opportuni-
ties for CAH bond activation. Future directions of this field are to
construct cost-effective and more environment-friendly chemical
transformations based on recyclable SMP platforms.
[31] W. Ji, J. Qu, S. Jing, D.-R. Zhu, W. Huang, Dalton Trans. 45 (2016) 1016–1024.
[
[
[
[
32] C.-A. Li, W. Ji, J. Qu, S. Jing, F. Gao, D.-R. Zhu, Dalton Trans. 47 (2018) 7463–
470.
7
33] W. Ji, J. Qu, C.-A. Li, J.-W. Wu, S. Jing, F. Gao, Y.-N. Lv, C. Liu, D.-R. Zhu, X.-M.
Ren, W. Huang, Appl. Catal. B: Environ. 205 (2017) 368–375.
34] C.R. Waidmann, A.J.M. Miller, C.-W.A. Ng, M.L. Scheuermann, T.R. Porter, T.A.
Tronic, J.M. Mayer, Energy Environ. Sci. 5 (2012) 7771–7780.
35] O.S. Wenger, Acc. Chem. Res. 46 (2013) 1517–1526.
[36] S. Hammes-Schiffer, J. Am. Chem. Soc. 137 (2015) 8860–8871.
[37] J.C. Lennox, D.A. Kurtz, T. Huang, J.L. Dempsey, ACS Energy Lett. 2 (2017) 1246–
1256.
[
38] C.-J. Tang, J.-F. Sun, X.-J. Yao, Y. Cao, L.-C. Liu, C.-Y. Ge, F. Gao, L. Dong, Appl.
Catal. B: Environ. 146 (2014) 201–212.
[39] X.-J. Yao, L. Zhang, L.-L. Li, L.-C. Liu, Y. Cao, X. Dong, F. Gao, Y. Deng, C.-J. Tang, Z.
Chen, L. Dong, Y. Chen, Appl. Catal. B: Environ. 150–151 (2014) 315–329.
[
[
[
40] X.-Y. Wu, W.-T. Wu, X.-N. Cui, J.-Z. Zhao, M.-B. Wu, J. Mater. Chem. C 4 (2016)
843–2853.
2
41] J. Qu, Q. Xia, W. Ji, S. Jing, D.-R. Zhu, L. Li, L. Huang, Z.-F. An, C.-Q. Xin, Y. Ni, M.-
X. Li, J.-D. Jia, Y.-L. Song, W. Huang, Dalton Trans. 47 (2018) 1479–1487.
42] M.W. Mara, K.A. Fransted, L.X. Chen, Coordin. Chem. Rev. 282–283 (2015) 2–
Acknowledgements
1
8.
This work is funded by the National Natural Science Foundation
of China (NSFC Project Nos. 21671101, 21871137, 21875104, and
[43] A. Badalyan, S.S. Stahl, Nature 535 (2016) 406–410.
5
1673095), Department of Ecological Environment of Jiangsu