Ruthenium(II)-Catalyzed Homocoupling of Weakly Coordinating Sulfoxonium Ylides via C?H Activation/Annulations: Synthesis of Functionalized Isocoumarins

Article abstract of DOI:10.1002/adsc.201900764

Homocoupling of weakly coordinating sulfoxonium ylides was accomplished via ruthenium (II) catalyzed C?H activation process. This strategy provides a convenient, efficient and step-economic method to access 3-substituted isocoumarins with good functional

Full text of DOI:10.1002/adsc.201900764

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DOI: 10.1002/adsc.201900764
Ruthenium(II)-Catalyzed Homocoupling of Weakly Coordinating
Sulfoxonium Ylides via CÀ H Activation/Annulations: Synthesis of
Functionalized Isocoumarins
Ming-Dong Zhou,a,* Zhen Peng,a He Wang,a,* Zhao-Hui Wang,a Da-Jin Hao,a
and Lei Lia
a
School of Chemistry and Materials Science, Liaoning Shihua University, Fushun 113001, People’s Republic of China
Fax: (+86)-24-56863837
phone: (+86)-24-56863837
E-mail: heliwang123@126.com; mingdong.zhou@lnpu.edu.cn
Manuscript received: June 21, 2019; Revised manuscript received: September 22, 2019;
Version of record online: ■■■, ■■■■
Supporting information for this article is available on the WWW under https://doi.org/10.1002/adsc.201900764
Abstract: Homocoupling of weakly coordinating sulfoxonium ylides was accomplished via ruthenium (II)
catalyzed CÀ H activation process. This strategy provides a convenient, efficient and step-economic method to
access 3-substituted isocoumarins with good functional group tolerance. The sulfoxonium ylide acts both as
the convenient aromatic substrate and the acylmethylation reagent in this transformation. Moreover, the
products could be transformed to diverse valuable derivatives.
Keywords: CÀ H Activation; Ruthenium(II) catalysis; Homocoupling; Isocoumarins; Sulfoxonium ylides
Introduction
synthetic intermediates which can be transformed into
useful molecules such as canesin, isochromenes, and
Isocoumarins are ubiquitous structural motifs widely alkaloids.[9] Given the substantial applications of
existed in natural products, pharmaceuticals, and isocoumarins, tremendous and persistent efforts have
bioactive compounds.[1–3] Among various isocoumarin been made to seek efficient methods to assemble this
derivatives, 3-substituted isocoumarins possess versa- scaffold. Traditional approaches to synthesis 3-substi-
tile pharmacophores such as anticancer,[4] anti- tuted isocoumarins generally rely on electrophilic
inflammatory,[5] antifungal,[6] antiallergic,[7] and anti- cyclization of substituted alkynes, or the metal-
HIV[8] activities and have been received much atten- catalyzed 2-haloaromatic acid/esters with terminal
tions (Figure 1). Moreover, they are also valuable alkynes.[10] However, most of these methods suffer
from the utilization of halogen functionalized reagents,
formation of isomeric mixtures of products, and multi-
step synthesis under harsh reaction conditions, which
limited their synthetic practicality and utility. There-
fore, the development of efficient, expeditious and
straightforward strategies for the construction of
isocoumarins is highly desirable.
During the past two decades, transition-metal-
catalyzed directing group-assisted CÀ H bond activation
have emerged as powerful tool to compose various
functionalized molecules in organic synthesis.[11]
Meanwhile, the synthesis of isocoumarins has been
witnessed the rapid development via Ru, Rh, Co, Pd,
or Ir complexes catalyzed CÀ H bond activations.[12]
Figure 1. Representative Naturally and Pharmacologically Ac-
tive 3-Substituted Isocoumarins.
Owing to the lower cost of [Ru(p-cymene)Cl2]2 (as
compared to Cp*Rh(III), Cp*Ir(III), or Cp*Co(III)
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Table 1. Optimization of the Reaction Conditions[a].
catalysts), the ruthenium(II)-catalyzed CÀ H activation
of arenes has been increasingly explored in recent
years.[13] In particular, the ruthenium(II)-catalyzed
CÀ H activation/annulation reaction has been recog-
nized as an important and valuable strategy for the
construction of heterocyclic compounds.[14] Despite
these considerable advances, very limited efforts have
been made to the synthesis of 3-substituted isocouu-
marins via ruthenium(II)-catalyzed CÀ H activations.
Recently, Ackermann’s group described a Ru(II)-
catalyzed coupling of aromatic acids with sulfoxonium
ylides[15] to synthesis 3-substituted isocouumarins.[12k]
Inspired by these work and as part of our interest in
CÀ H activation reactions,[16] we recently developed a
Ru(II)-catalyzed homocoupling of weakly coordinating
sulfoxonium ylides to synthesize 3-substituted isocouu-
marins. Therefore, we wish to report the primary
results of this work herein.
Entry
Additive (equiv.)
Solvent
Yield[b]
1
2
3
4
5
6
7
8
AcOH (1)
AcOH (2)
TFE
TFE
TFE
TFE
TFE
TFE
TFE
EtOH
DCE
DMF
HFIP
TFE
TFE
TFE
TFE
TFE
91
76
67
85
79
22
70
trace
84
68
51
41
trace
trace
74
2,4-Me2PhCOOH (1)
AdCO2H (1)
PivOH (1)
Zn(OTf)1 (1)
Cu(OAc)2 ·H2O (1)
AcOH (1)
AcOH (1)
AcOH (1)
AcOH (1)
AcOH (1)
9
10
11
12[c]
13[d]
14
15[e]
16[f]
AcOH (1)
Results and Discussion
At the outset of our studies, we selected sulfoxonium
ylide 1a as the model substrate to optimize the reaction
conditions. Our initial efforts revealed that the reaction
could be activated with [Ru(p-cymene)Cl2]2 (5 mol%)/
AgSbF6 (20 mol%) in the presence of 1 equiv. AcOH
AcOH (1)
AcOH (1)
71
[a] Reactions were carried out using 1a (0.4 mmol), [Ru(p-
cymene)Cl2]2 (5 mol%), AgSbF6 (20 mol%), and additive
(0.4 mmol) in a solvent (2 mL) for 12 h.
°
[b] Isolated yield.
in TFE at 100 C for 12 h under N2 (for more details
[c] [RhCp*Cl2]2 (5.0 mol%) was applied as the catalyst.
see Table S1 of SI). To further optimize the reaction
condition, the variation of additives such as 2,4-
Me2PhCOOH, AdCO2H (1-Adamantanecarboxylic
acid), PivOH, Zn(OTf)2, and Cu(OAc)2 ·H2O were
investigated. Unfortunately, these additives led to only
[d] Cp*Co(CO)I2 (5.0 mol%) was applied as the catalyst.
[e]
[f]
°
°
80 C. 120 C.
poor conversion of sulfoxonium ylide 1a (entries 1–7). Meta-substituted sulfoxonium ylides bearing methyl,
Screening of solvents indicated that TFE was better fluroro, chloro, and trifluoromethyl at the benzene
than EtOH, DCE, DMF, and HFIP (entries 8–11). rings also proceeded well at the less hindered site,
When switching the ruthenium catalyst to Rh(III) furnishing the annulated products in moderate to
catalyst ([RhCp*Cl2]2) or Co(III) catalyst (Cp*Co(CO) excellent yields (2i–2k). In the case of meta-trifluor-
I2), the reaction could not be activated however omethoxy sulfoxonium ylide, the reaction afforded a
(entries 12–13). Control experiment indicated that the mixture of two regioisomeric products 2l and 2 l’ with
introduction of an acid additive is necessary for this a total yield of 79% in approximately 1:1.45 ratio.
transformation (entry 14). Likely, the acid additive not Introduction of electron-donating and halogen groups
only help to facilitate the CÀ H activation, but also at the ortho-position of phenyl ring could be well
promote the intramolecular cyclization process. Low- tolerated to this transformation (2m–2o). Unfortu-
°
ing down the temperature to 80 C resulted in nately, the reactions using thiophene or furan rings did
diminished yield (entry 15), and 71% of 2a was not take place under the standard conditions. Notably,
°
isolated when increasing the temperature to 120 C di/tri-substituted sulfoxonium ylides were also viable
(entry 16).
for this transformation. (2p–2r). Besides the homo-
With the optimized reaction conditions in hand, coupling reaction, we were also curious to examine the
various sulfoxonium ylides were subsequently utilized cross-coupling mode of sulfoxonium ylides. First, the
to investigate the scope and generality of this homo- coupling of 1e with 1h was carried out under the
coupling reaction (Table 2). Sulfoxonium ylides bear- standard conditions, and the reaction afforded a
ing electron-donating, halogen, and electron-withdraw- mixture of 2e (20%), 2h (12%), 2eh (21%), and 2he
ing groups at the para-position of phenyl ring all (10%). The molecular structure of 2eh and 2he was
coupled smoothly to afford the targeted isocoumarins also confirmed by H-1H NOESY spectra (for more
1
with moderated to excellent yields (2b–2h). The details see the SI). In addition, coupling of 1a with 1s
molecular structure of 2b was unambiguously con- yielded a mixture of 2a (53%) and 2s (36%). When
firmed by X-ray crystallography (CCDC 1917189).[17] less steric hindered alkyl sufoxonium ylides 1t–1v
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Table 2. Scope of Sulfoxonium Ylides[a]
Figure 2. Derivatives of 3-Substituted Isocouumarins and Deu-
terium Labeling Experiment.
reversible.[12j] Furthermore, the observed deuterium
incorporation at the olefinic position of [D]n-2a may
suggest enolization of the alkylation intermediate F,
which may due to the enhanced acidity of the meth-
ylene protons.
On the basis of the above experimental results and
related reports,[12j,k,21] a plausible mechanism is pro-
posed as shown in Scheme 1. First, cyclometalation of
sulfoxonium ylide 1 gives a metalacyclic intermdiate
B. Next, the coordination of B with sulfoxonium ylide
1 affords ruthenium(II) species C, which is then
transformed into a key ruthenium(II) carbene species
D by α-elimination of DMSO. The subsequent
migratory insertion of the RuÀ C(Ar) bond into carbene
[a] Reactions were carried out using 1 (0.4 mmol), [Ru(p-
cymene)Cl2]2 (5 mol%), AgSbF6 (20 mol%), and AcOH
(0.2 mmol) in TFE (2 mL) for 12 h.
[b] Isolated yield.
[c] Reactions were carried out using 1a (0.2 mmol), 1s
(0.8 mmol).
were applied, the reaction delivered 2t–2v as the moiety of D generates a six-membered ruthenacyclic
major cross-coupling products in good yields.
intermediate E. Then, E undergoes protonolysis to
Based on the above studies, we next investigated
the synthetic applications of the obtained functional-
ized isocouumarins. In the presence of BBr3, isocouu-
marins 2q could be deprotected to the analogous
thunberginol 3q in 48% yield (Figure 2, eq 1).[18]
Under the Grignard reaction condition, 3-substituted
isocoumarin 2a could be nicely transferred to the
corresponding benzophenone 4a (Figure 2, eq 2).[12j]
Ammoniation of 2a in the presence of an excess
amount of aqueous ammonia readily afforded the
corresponding 3-phenylisoquinolin-1(2H)-one 5a in
95% yield (Figure 2, eq 3).[19] Treatment of 2a with
hydrazine hydrate delivered the ring-expanding prod-
uct in 86% yield (Figure 2, eq 4).[20] To get some
insights into the reaction mechanism, control experi-
ment was performed (Figure 2, eq 5 ). The H/D
exchange homocoupling of 1a under the standard
conditions was carried out in the presence of CD3OD,
and the result suggests that the CÀ H activation is
Scheme 1. Postulated Mechanism.
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NMR (400 MHz, CDCl3) δ 8.23 (d, J=8.4 Hz, 1H), 7.83 (d,
J=8.8 Hz, 2H), 7.54 (dd, J=8.4, 2.0 Hz, 1H), 7.49–7.46 (m,
3H), 6.93 (s, 1H), 1.39 (s, 9H), 1.36 (s, 9H). 13C NMR
(100 MHz, CDCl3) δ 162.5, 158.8, 153.7, 153.3, 137.7, 129.4,
129.3, 126.0, 125.8, 125.0, 122.2, 118.0, 101.7, 35.4, 34.9, 31.2,
31.0. HRMS (ESI): calcd for C23H26O2 ([M+Na]+) 357.1825,
found 357.1824.
form an alkylation intermediate F, and further transfers
to intermediate G in the presence of acid. Finally, an
intramolecular nucleophilic attack of the enol oxygen
furnishes isocouumarin 2, meanwhile releasing a
Corey’s ylide.[22] The formation of benzyloxirane was
confirmed by trapping with phenylacetaldehyde, sug-
gesting that the Corey’s ylide could form in our
reaction system (for more details see the SI).[23]
6-Methoxy-3-(4-methoxyphenyl)-1H-isochromen-1-one (2e);
1
°
White solid, m.p. 146–147 C, 39.3 mg, yield: 70%. H NMR
(400 MHz, CDCl3) δ 8.19 (d, J=8.8 Hz, 1H), 7.80 (d, J=
8.8 Hz, 2H), 7.00–6.94 (m, 3H), 6.82 (d, J=2.4 Hz, 1H), 6.75
(s, 1H), 3.91 (s, 3H), 3.86 (s, 3H). 13C NMR (100 MHz, CDCl3)
δ 164.7, 162.2, 161.1, 154.2, 140.2, 131.8, 126.8, 124.6, 116.2,
114.2, 113.3, 107.6, 100.3, 55.6, 55.4. HRMS (ESI): calcd for
C17H14O4 ([M+Na]+) 305.0784, found 305.0779.
Conclusion
In conclusion, we have developed a ruthenium(II)-
catalyzed homocoupling of weakly coordinating sul-
foxonium ylides involving CÀ H activation/intramolec-
ular nucleophilic addition/elimination process. This
reaction protocol provides a simple, efficient, step-
economic approach with excellent functional group
compatibility to access synthetically and pharmaceuti-
cally valuable 3-substituted isocouumarins. More im-
portantly, the sufoxonium ylide acts both as the
convenient aromatic substrate and the acylmethylation
reagents in this transformation.
6-Fluoro-3-(4-fluorophenyl)-1H-isochromen-1-one
(2f);
White solid, m.p. 158–159 C, 30 mg, yield: 58%. 1H NMR
(400 MHz, CDCl3) δ 8.32 (dd, J=8.8, 5.6 Hz, 1H), 7.90–7.84
(m, 2H), 7.22–7.13 (m, 4H), 6.85 (s, 1H). 13C NMR (100 MHz,
CDCl3) δ 166.8 (d, J=255.2 Hz), 164.0 (d, J=250.1 Hz),
161.2, 154.0, 140.1 (d, J=10.8 Hz), 133.1 (d, J=10.4 Hz),
127.8 (d, J=3.3 Hz), 127.5 (d, J=8.6 Hz), 116.8 (d, J=
2.2 Hz), 116.5 (d, J=23.1 Hz), 116.1 (d, J=21.9 Hz), 111.5 (d,
J=22.4 Hz), 101.0 (dd, J=2.7, 1.7 Hz). 19F NMR (377 MHz,
CDCl3) δ À 109.5, À 101.6. HRMS (ESI): calcd for C15H8F2O2
([M+Na]+) 281.0385, found 281.0383.
°
Experimental Section
General Procedure for Synthesis of 2
6-Chloro-3-(4-chlorophenyl)-1H-isochromen-1-one
(2g);
1
°
A
pressure tube was charged with [RuCl2(p-cymene)]2
White solid, m.p. 227–228 C, 48.7 mg, yield: 84%. H NMR
(400 MHz, CDCl3) δ 8.23 (d, J=8.4 Hz, 1H), 7.81 (d, J=
8.4 Hz, 2H), 7.49–7.44 (m, 4H), 6.86 (s, 1H). 13C NMR
(100 MHz, CDCl3) δ 161.3, 153.9, 141.7, 138.7, 136.5, 131.4,
130.0, 129.2, 128.9, 126.7, 125.5, 118.8, 101.1. HRMS (ESI):
calcd for C15H8Cl2O2 ([M+Na]+) 312.9794, found 312.9798.
(5 mol%), AgSbF6 (20 mol%), AcOH (1 equiv.), sulfoxonium
ylides (1, 0.4 mmol) and TFE (1 mL). The reaction mixture was
°
stirred under N2 condition at 100 C for 12 h. Then, the solvent
was removed under reduced pressure and the residue was
purified by silica gel chromatography with PE/EA to afford the
product 2.
6-(Trifluoromethyl)-3-(4-(trifluoromethyl)phenyl)-1H-iso-
3-Phenyl-1H-isochromen-1-one (2a);[12j] White solid, 40.2 mg,
°
chromen-1-one (2h); White solid, m.p. 175–176 C, 52.9 mg,
yield: 74%. H NMR (400 MHz, CDCl3) δ 8.44 (d, J=8.4 Hz,
1
1
yield: 91%. H NMR (400 MHz, CDCl3) δ 8.30 (d, J=8.4 Hz,
1H), 7.88–7.85 (m, 2H), 7.72–7.68 (m, 1H), 7.50–7.41 (m, 5H),
6.94 (s, 1H). 13C NMR (100 MHz, CDCl3) δ 162.3, 153.6,
137.5, 134.9, 132.0, 130.0, 129.6, 128.8, 128.2, 126.0, 125.2,
120.5, 101.8.
1H), 8.00 (d, J=8.0 Hz, 2H), 7.81 (s, 1H), 7.77–7.73 (m, 3H),
7.10 (s, 1H). 13C NMR (100 MHz, CDCl3) δ 160.6, 153.4,
137.3, 136.6, (q, J=32.6 Hz) 134.6, 132.2 (q, J=32.6 Hz),
130.8, 126.0 (q, J=3.8 Hz), 125.7, 125.0 (q, J=3.2 Hz ), 123.7
(q, J=270.8 Hz), 123.4 (q, J=3.6 Hz), 123.2 (q, J=271.7 Hz),
123.1, 102.7. 19F NMR (377 MHz, CDCl3) δ À 62.9, À 63.5.
HRMS (ESI): calcd for C17H8F6O2 ([M+Na]+) 381.0321, found
381.0327.
6-Methyl-3-(p-tolyl)-1H-isochromen-1-one (2b);[10b] White
1
solid, 45.0 mg, yield: 90%. H NMR (400 MHz, CDCl3) δ 8.17
(d, J=8.0 Hz, 1H), 7.76 (d, J=8.4 Hz, 2H), 7.29–7.24 (m, 4H),
6.83 (s, 1H), 2.47 (s, 3H), 2.40 (s, 3H). 13C NMR (100 MHz,
CDCl3) δ 162.5, 153.9, 145.9, 140.2, 137.8, 129.6, 129.5, 129.4,
129.3, 125.8, 125.2, 118.1, 101.1, 22.0, 21.4.
7-Methyl-3-(m-tolyl)-1H-isochromen-1-one (2i);[10b] White
1
solid, 46.3 mg, yield: 93%. H NMR (400 MHz, CDCl3) δ 8.10
(s, 1H), 7.69 (s, 1H), 7.64 (d, J=8.0 Hz, 1H), 7.53–7.50 (m,
1H), 7.37 (d, J=8.0 Hz, 1H), 7.32 (t, J=7.6 Hz, 1H), 7.21 (d,
J=7.6 Hz, 1H), 6.90 (s, 1H), 2.45 (s, 3H), 2.41 (s, 3H). 13C
NMR (100 MHz, CDCl3) δ 162.6, 153.0, 138.5, 138.4, 136.2,
135.1, 132.0, 130.6, 129.3, 128.7, 125.9, 125.7, 122.2, 120.4,
101.7, 21.5, 21.4.
6-Ethyl-3-(4-ethylphenyl)-1H-isochromen-1-one (2c); White
1
°
solid, m.p. 55–56 C, 52.2 mg, yield: 94%. H NMR (400 MHz,
CDCl3) δ 8.21 (d, J=8.4 Hz, 1H), 7.80 (d, J=8.0 Hz, 2H),
7.33–7.28 (m, 4H), 6.88 (s, 1H), 2.77 (q, J=7.6 Hz, 2H), 2.70
(q, J=7.6 Hz, 2H), 1.31 (t, J=7.6 Hz, 3H), 1.27 (t, J=7.6 Hz,
3H). 13C NMR (100 MHz, CDCl3) δ 162.5, 153.9, 152.0, 146.4,
137.9, 129.7, 129.6, 128.4, 128.3, 125.3, 124.6, 118.2, 101.3,
29.2, 28.7, 15.4, 15.1. HRMS (ESI): calcd for C19H18O2 ([M+
Na]+) 301.1199, found 301.1200.
7-Fluoro-3-(3-fluorophenyl)-1H-isochromen-1-one
(2j);
White solid, m.p. 165–166 C, 41 mg, yield: 80%. 1H NMR
(400 MHz, CDCl3) δ 8.10 (dd, J=7.2, 2.0 Hz, 1H), 7.68 (d, J=
8.0 Hz, 1H), 7.59 (dt, J=10.0, 2.0 Hz, 1H), 7.50–7.41 (m, 3H),
7.16–7.11 (m, 2H). 13C NMR (100 MHz, CDCl3) δ 163.1 (d, J=
245.3 Hz), 160.6 (d, J=3.6 Hz), 157.3 (d, J=251.5 Hz), 152.8
°
6-(tert-Butyl)-3-(4-(tert-butyl)phenyl)-1H-isochromen-1-one
1
°
(2d); White solid, m.p. 139–140 C, 53.2 mg, yield: 80%. H
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(d, J=4.0 Hz), 133.8 (d, J=8.1 Hz), 130.5 (d, J=8.2 Hz),
128.9 (d, J=7.7 Hz), 126.3 (d, J=16.7 Hz), 125.4 (d, J=
3.9 Hz), 122.0 (d, J=3.8 Hz), 121.0 (d, J=3.1 Hz), 120.4 (d,
J=19.6 Hz), 117.2 (d, J=21.2 Hz), 112.4 (d, J=23.8 Hz), 95.1
(d, J=5.0 Hz). 19F NMR (377 MHz, CDCl3) δ À 111.8, À 120.7.
HRMS (ESI): calcd for C15H8F2O2 ([M+Na]+) 281.0385, found
281.0384.
J=4.3 Hz), 119.6 (d, J=9.7 Hz), 116.5 (d, J=22.7 Hz), 115.7
(d, J=21.1 Hz), 109.6 (d, J=7.4 Hz), 106.5 (dd, J=16.0,
3.0 Hz). 19F NMR (377 MHz, CDCl3) δ À 107.1, À 111.7.
HRMS (ESI): calcd for C15H8F2O2 ([M+Na]+) 281.0385, found
281.0383.
8-Chloro-3-(2-chlorophenyl)-1H-isochromen-1-one
(2o);
1
°
White solid, m.p. 150–151 C, 14.2 mg, yield: 25%. H NMR
(400 MHz, CDCl3) δ 7.75–7.71 (m, 1H), 7.62–7.54 (m, 2H),
7.52–747 (m, 1H), 7.41–7.37 (m, 3H), 6.96 (s, 1H). 13C NMR
(100 MHz, CDCl3) δ 158.8, 152.0, 140.0, 137.2, 134.6, 132.3,
131.5, 131.0, 130.9, 130.7, 130.6, 127.1, 125.2, 117.8, 107.5.
HRMS (ESI): calcd for C15H8Cl2O2 ([M+Na]+) 312.9794,
found 312.9796.
7-(Trifluoromethyl)-3-(3-(trifluoromethyl)phenyl)-1H-iso-
°
chromen-1-one (2k); White solid, m.p. 169–170 C, 59.8 mg,
yield: 84%. 1H NMR (400 MHz, CDCl3) δ 8.58 (s, 1H), 8.13 (s,
1H), 8.08 (d, J=8.0 Hz, 1H), 7.96 (dd, J=8.4, 2.0 Hz, 1H),
7.73 (d, J=7.6 Hz, 1H), 7.67 (d, J=8.0 Hz, 1H), 7.63 (t, J=
8.0 Hz, 1H), 7.08 (s, 1H). 13C NMR (100 MHz, CDCl3) δ 160.7,
154.0, 139.7, 132.2, 132.7 (q, J=32.6 Hz), 131.4 (q, J=
3.4 Hz), 130.7 (q, J=33.5 Hz), 129.6, 128.6, 127.3 (q, J=
4.0 Hz), 127.2 (q, J=3.7 Hz), 127.0, 123.7 (q, J=270.9 Hz),
123.3 (q, J=270.8 Hz), 122.3 (q, J=3.8 Hz), 120.8, 102.0. 19F
NMR (377 MHz, CDCl3) δ À 62.80, À 62.83; HRMS (ESI):
calcd for C17H8F6O2 ([M+Na]+) 381.0321, found 381.0321.
3-(3,5-Dimethylphenyl)-5,7-dimethyl-1H-isochromen-1-one
1
°
(2p); White solid, m.p. 213–214 C, 14.2 mg, yield: 21%. H
NMR (400 MHz, CDCl3) δ 7.99 (s, 1H), 7.51 (s, 2H), 7.38 (s,
1H), 7.06 (s, 1H), 7.01 (s, 1H), 2.53 (s, 3H), 2.43 (s, 3H), 2.39
(s, 6H). 13C NMR (100 MHz, CDCl3) δ 163.1, 152.7, 138.4,
137.7, 137.2, 133.9, 133.4, 132.3, 131.5, 127.3, 123.0, 120.5,
98.5, 21.4, 21.3, 18.8. HRMS (ESI): calcd for C19H18O2 ([M+
Na]+) 301.1199, found 301.1193.
7-(Trifluoromethoxy)-3-(3-(trifluoromethoxy)phenyl)-1H-
isochromen-1-one (2l); White solid, m.p. 103–104 C,
°
24.6 mg, yield: 32%. 1H NMR (400 MHz, CDCl3) δ 8.28 (d, J=
7.6 Hz, 1H), 7.86–7.83 (m, 1H), 7.75 (s, 1H), 7.67 (dt, J=8.0,
1.6 Hz, 1H), 7.56 (d, J=8.0 Hz, 1H), 7.52 (d, J=8.0 Hz, 1H),
7.35–7.32 (m, 1H), 7.18 (s, 1H). 13C NMR (100 MHz, CDCl3) δ
160.5, 153.2, 149.8, 143.9, 133.7, 130.8, 130.5, 128.7, 128.3,
126.3, 123.8, 122.7, 122.3, 120.6 (q, J=258.1 Hz), 120.4 (q,
J=256.5 Hz), 118.4, 96.0. 19F NMR (377 MHz, CDCl3) δ
À 57.7, À 57.8. HRMS (ESI): calcd for C17H8F6O4 ([M+Na]+)
413.0219, found 413.0216.
3-(3,5-Dimethoxyphenyl)-5,7-dimethoxy-1H-isochromen-1-
°
one (2q); White solid, m.p. 195–196 C, 41.5 mg, yield: 61%.
1H NMR (400 MHz, CDCl3) δ 7.28 (d, J=2.4 Hz, 1H), 7.22 (s,
1H), 7.00 (d, J=2.4 Hz, 2H), 6.73 (d, J=2.4 Hz, 1H), 6.49 (t,
J=2.4 Hz, 1H), 3.93 (s, 3H), 3.91 (s, 3H), 3.86 (s, 6H). 13C
NMR (100 MHz, CDCl3) δ 162.3, 161.0, 160.3, 155.7, 150.8,
134.4, 122.5, 122.1, 105.1, 102.9, 101.9, 101.0, 96.8, 56.0,
55.9, 55.6. HRMS (ESI): calcd for C19H18O6 ([M+Na]+)
365.0996, found 365.0989.
5-(Trifluoromethoxy)-3-(3-(trifluoromethoxy)phenyl)-1H-
3-(2,3-Dimethoxyphenyl)-7,8-dimethoxy-1H-isochromen-1-
°
isochromen-1-one (2 l’); White solid, m.p. 115–116 C,
°
one (2r); White solid, m.p. 129–130 C, 28.5 mg, yield: 42%.
1
35.6 mg, yield: 47%. H NMR (400 MHz, CDCl3) δ 8.14 (s,
1H NMR (400 MHz, CDCl3) δ 7.47 (dd, J=8.0, 1.6 Hz, 1H),
7.35 (d, J=8.4 Hz, 1H), 7.25 (s, 1H), 7.23 (d, J=8.4 Hz, 1H),
7.14 (t, J=8.0 Hz, 1H), 6.97 (dd, J=8.0, 1.6 Hz, 1H), 4.01 (s,
3H), 3.95 (s, 3H), 3.92 (s, 3H), 3.87 (s, 3H). 13C NMR
(100 MHz, CDCl3) δ 159.0, 153.2, 152.8, 150.9, 148.6, 147.1,
132.5, 126.4, 124.3, 122.3, 120.3, 120.0, 115.3, 113.4, 106.5,
61.6, 60.5, 56.7, 56.0. HRMS (ESI): calcd for C19H18O6 ([M+
Na]+) 365.0996, found 365.0999.
1H), 7.81 (d, J=8.4 Hz, 1H), 7.71 (s, 1H), 7.59–7.58 (m, 2H),
7.51 (t, J=8.4 Hz, 1H), 7.32–7.29 (m, 1H), 6.99 (s, 1H). 13C
NMR (100 MHz, CDCl3) δ 160.7, 152.4, 149.8 (q, J=1.8 Hz),
148.8 (q, J=1.9 Hz), 135.6, 133.6, 130.5, 128.2, 123.6, 122.6,
122.0, 121.2, 121.1, 120.4 (q, J=256.3 Hz), 120.3 (q, J=
257.4 Hz), 118.0, 101.8. 19F NMR (377 MHz, CDCl3) δ À 57.8,
À 58.0. HRMS (ESI): calcd for C17H8F6O4 ([M+Na]+)
413.0219, found 413.0218.
3-(tert-Butyl)-1H-isochromen-1-one (2s);[12j] Yellow oil,
8-Methoxy-3-(2-methoxyphenyl)-1H-isochromen-1-one
1
15.0 mg, yield: 36%. H NMR (400 MHz, CDCl3) δ 8.27–8.25
1
°
(2m); White solid, m.p. 168–169 C, 43 mg, yield: 76%. H
(m, 1H), 7.69–7.65 (m, 1H), 7.47–7.38 (m, 1H), 7.39 (d, J=
7.6 Hz, 1H), 6.31 (s, 1H), 1.33 (s, 9H). 13C NMR (100 MHz,
CDCl3) δ 165.2, 163.1, 137.7, 134.6, 129.4, 127.6, 125.5, 120.1,
99.7, 35.6, 28.0.
NMR (400 MHz, CDCl3) δ 7.98 (dd, J=7.6, 1.6 Hz, 1H), 7.59
(t, J=8.0 Hz, 1H), 7.38–7.34 (m, 1H), 7.28 (s, 1H), 7.07–7.02
(m, 2H), 6.98 (d, J=8.0 Hz, 1H), 6.92 (d, J=8.0 Hz, 1H), 4.01
(s, 3H), 3.95 (s, 3H). 13C NMR (100 MHz, CDCl3) δ 161.5,
159.4, 157.2, 150.7, 141.0, 135.5, 130.7, 128.9, 120.8, 120.6,
118.5, 111.3, 109.7, 109.4, 107.0, 56.3, 55.6. HRMS (ESI):
calcd for C17H14O4 ([M+Na]+) 305.0784, found 305.0790.
3-Cyclohexyl-1H-isochromen-1-one (2t);[10h] White solid,
25.8 mg, yield: 57%. 1H NMR (400 MHz, CDCl3) δ 8.25 (d, J=
8.0 Hz, 1H), 7.66 (t, J=7.6 Hz, 1H), 7.44 (t, J=7.6 Hz, 1H),
7.36 (d, J=7.6 Hz, 1H), 6.23 (s, 1H), 2.47–2.41 (m, 1H), 2.05–
1.73 (m, 5H), 1.50–1.23 (m, 5H).13C NMR (100 MHz, CDCl3) δ
163.2, 162.4, 137.8, 134.7, 129.5, 127.5, 125.3, 120.3, 100.9,
41.9, 30.6, 26.0, 25.9.
8-Fluoro-3-(2-fluorophenyl)-1H-isochromen-1-one
(2n);
1
°
White solid, m.p. 171–172 C, 25.7 mg, yield: 50%. H NMR
(400 MHz, CDCl3) δ 8.00 (td, J=8.0, 2.0 Hz, 1H), 7.68 (td, J=
8.0, 5.2 Hz, 1H), 7.43–7.38 (m, 1H), 7.31–7.25 (m, 2H), 7.20–
7.14 (m, 3H). 13C NMR (100 MHz, CDCl3) δ 162.9 (d, J=
265.2 Hz), 160.1 (d, J=251.6 Hz), 157.5 (d, J=5.4 Hz), 149.0
(d, J=4.9 Hz), 140.0, 136.3 (d, J=10.1 Hz), 131.5 (d, J=
9.1 Hz), 128.6 (d, J=1.7 Hz), 124.7 (d, J=3.6 Hz), 122.3 (d,
3-Isobutyl-1H-isochromen-1-one (2u);[10f] Yellow solid,
1
24.3 mg, yield: 60%. H NMR (400 MHz, CDCl3) δ 8.27–8.24
(m, 1H), 7.70–7.66 (m, 1H), 7.47–7.43 (m, 1H), 7.36 (d, J=
8.0 Hz, 1H), 6.25 (s, 1H), 2.39 (d, J=7.6 Hz, 2H), 2.20–2.10
Adv. Synth. Catal. 2019, 361, 1–8
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(m, 1H), 0.98 (d, J=6.4 Hz, 6H). 13C NMR (100 MHz, CDCl3)
δ 163.2, 157.4, 137.6, 134.7, 129.5, 127.6, 125.0, 120.1, 104.0,
42.8, 26.6, 22.3.
[7] M. Yoshikawa, E. Harada, Y. Naitoh, K. Inoue, H.
Matsuda, H. Shimoda, J. Yamahara, N. Murakami,
Chem. Pharm. Bull. 1994, 42, 2225–2230.
[8] Y. Shikishima, Y. Takaishi, G. Honda, M. Ito, Y. Takeda,
O. K Kodzhimatov, O. Ashurmetov, K. H. Lee, Chem.
Pharm. Bull. 2001, 49, 877–880.
3-Butyl-1H-isochromen-1-one (2v);[12g] Colorless liquid,
25.4 mg, yield: 63%. H NMR (400 MHz, CDCl3) δ 8.26–8.24
(m, 1H), 7.70–7.65 (m, 1H), 7.47–7.43 (m, 1H), 7.35 (d, J=
8.0 Hz, 1H), 6.26 (s, 1H), 2.53 (t, J=7.6 Hz, 2H), 1.73–1.67
(m, 2H), 1.45–1.36 (m, 2H), 0.95 (t, J=7.2 Hz, 3H). 13C NMR
(100 MHz, CDCl3) δ 163.2, 158.3, 137.7, 134.7, 129.5, 127.5,
125.0, 120.1, 102.9, 33.2, 29.0, 22.1, 13.8.
1
[9] a) S. Pal, V. Chatare, M. Pal, Curr. Org. Chem. 2011, 15,
782–800; b) M. Conda-Sheridan, E.-J. Park, D. E. Beck,
P. V. N. Reddy, T. X. Nguyen, B. J. Hu, L. Chen, J. J.
White, R. B. van Breemen, J. M. Pezzuto, M. Cushman,
J. Med. Chem. 2013, 56, 2581–2605; c) C. Dasaradhan,
Y. S. Kumar, F.-R. N. Khan, E. D. Jeong, E. H. Chung,
Tetrahedron Lett. 2015, 56, 187–191; d) W. Li, M. P.
Wiesenfeldt, F. Glorius, J. Am. Chem. Soc. 2017, 139,
2585–2588.
[10] Selected references a) P. Zhao, D. Chen, G. Song, K.
Han, X. Li, J. Org. Chem. 2012, 77, 1579–1584; b) D.
Nandi, D. Ghosh, S. J. Chen, B. C. Kuo, N. M. Wang,
H. M. Lee, J. Org. Chem. 2013, 78, 3445–3451; c) H.
Liu, Y. Yang, J. Wu, X.-N. Wang, J. Chang, Chem.
Commun. 2016, 52, 6801–6804; d) J. Zhang, X. Han, X.
Lu, J. Org. Chem. 2016, 81, 3423–3429; e) D. J. Faizi,
A. Issaian, A. J. Davis, S. A. Blum, J. Am. Chem. Soc.
2016, 138, 2126–2129; f) A. Casnati, R. Maggi, G.
Maestri, N. Della Ca’, E. Motti, J. Org. Chem. 2017, 82,
8296–8303; g) X. W. Wang, C. L. Wu, Y. W. Sun, X. Q.
Yao, Tetrahedron Lett. 2017, 58, 3164–3167; h) M. Sun,
L. Su, J. Dong, L. Liu, Y. Zhou, S.-F. Yin, Tetrahedron
Lett. 2017, 58, 2433–2437; i) Y. Kita, T. Yata, Y.
Nishimoto, K. Chibac, M. Yasuda, Chem. Sci. 2018, 9,
6041–6052; j) L. Habert, P. Retailleaub, I. Gillaizeau,
Org. Biomol. Chem. 2018, 16, 7351–7355.
Acknowledgements
We acknowledge financial supports from the National Natural
Science Foundation of China (21702087, and 21801105),
Natural Science Foundation of Liaoning Province
(2015020196, 20170520353, and 20180510033), the Program
for Liaoning Innovative Talents in University (LR2017021),
Research Project Fund of Liaoning Provincial Department of
Education (L2017LQN010 and L2017LZD001), Talent Scien-
tific Research Fund of Liaoning Shihua University (2016XJJ-
078 and 2016XJJ-079), the open project of Jilin Province Key
Laboratory of Organic Functional Molecular Design & Syn-
thesis (No. 130028836 and 130028911).
References
[1] For reviews, see: a) R. D. Barry, Chem. Rev. 1964, 64,
229–260; b) M. Hussain, M. T. Hussain, N. H. Rama, S.
Hameed, A. Malik, K. M. Khan, Nat. Prod. Res. 2003,
17, 207–214; c) S. Pal, V. Chatare, M. Pal, Curr. Org.
Chem. 2011, 15, 782–800.
[11] For selected reviews, see: a) B. Ye, N. Cramer, Acc.
Chem. Res. 2015, 48, 1308–1318; b) B. Su, Z.-C. Cao,
Z.-J. Shi, Acc. Chem. Res. 2015, 48, 886–896; c) H.
Huang, X. Ji, W. Wu, H. Jiang, Chem. Soc. Rev. 2015,
44, 1155–1171; d) Z. Chen, B. Wang, J. Zhang, W. Yu,
Z. Liu, Y. Zhang, Org. Chem. Front. 2015, 2, 1107–
1295; e) W. Liu, L. Ackermann, ACS Catal. 2016, 6,
3743–3752; f) F. Wang, S. Yu, X. Li, Chem. Soc. Rev.
2016, 45, 6462–6477; g) T. Gensch, M. N. Hopkinson, F.
Glorius, J. Wencel-Delord, Chem. Soc. Rev. 2016, 45,
2900–2936; h) G. He, B. Wang, W. A. Nack, G. Chen,
Acc. Chem. Res. 2016, 49, 635–645; i) Y. Park, Y. Kim,
S. Chang, Chem. Rev. 2017, 117, 9247–9301; j) J. He, M.
Wasa, K. S. L. Chan, Q. Shao, J.-Q. Yu, Chem. Rev.
2017, 117, 8754–8786; k) J. R. Hummel, J. A. Boerth,
J. A. Ellman, Chem. Rev. 2017, 117, 9163; l) Z. Dong, Z.
Ren, S. J. Thompson, Y. Xu, G. B. Dong, Chem. Rev.
2017, 117, 9333–9403; m) Y. Wei, P. Hu, M. Zhang, W.
Su, Chem. Rev. 2017, 117, 8864–8907; n) P. Gandeepan,
T. Müller, D. Zell, G. Cera, S. Warratz, L. Ackermann,
Chem. Rev. 2019, 119, 2192–2452.
[2] a) F. Bellina, D. Ciucci, P. Vergamini, R. Rossi,
Tetrahedron. 2000, 56, 2533–2545; b) W. Zhang, K.
Krohn, S. Draeger, B. Schulz, J. Nat. Prod. 2008, 71,
1078–1081; c) A. C. Tadd, M. R. Fielding, M. C. Willis,
Chem. Commun. 2009, 6744–6746; d) K. M. Khan, S.
Ahmed, S. Hussain, N. Ambreen, S. Perveen, M. I.
Choudhary, Lett. Drug Des. Discovery 2010, 7, 265–268.
[3] a) N. A. Gormley, G. Orphanides, A. Meyer, P. M.
Cullis, A. Maxwell, Biochemistry. 1996, 35, 5083–5092;
b) T. Suzuki, T. Yamada, K. Watanabe, T. Katoh, Bioorg.
Med. Chem. Lett. 2005, 15, 2583–2585; c) M. Uchiyama,
H. Ozawa, K. Takuma, Y. Matsumoto, M. Yonehara, K.
Hiroya, T. Sakamoto, Org. Lett. 2006, 8, 5517–5520;
d) A. Kurume, Y. Kamata, M. Yamashita, Q. Wang, H.
Matsuda, M. Yoshikawa, I. Kawasaki, S. Ohta, Chem.
Pharm. Bull. 2008, 56, 1264–1269.
[4] M. E. Riveiro, A. Moglioni, R. Vazquez, N. Gomez, G.
Facorro, L. Piehl, E. R. De Celis, C. Shayo, C. Davio,
Bioorg. Med. Chem. 2008, 16, 2665–2675.
[5] T. Furuta, Y. Fukuyama, Y. Asakawa, Phytochemistry
1986, 25, 517–520.
[6] a) B. Kalinova, J. Kindl, P. Jiros, P. Zacek, S. Vasickova,
M. Budesinsky, I. Valterova, J. Nat. Prod. 2009, 72, 8–
13; b) V. Rukachaisirikul, A. Rodglin, Y. Sukpondma, S.
Phongpaichit, J. Buatong, J. Sakayaroj, J. Nat. Prod.
2012, 75, 853–858.
[12] a) D. A. Frasco, C. P. Lilly, P. D. Boyle, E. A. Ison, ACS
Catal. 2013, 3, 2421–2429; b) Y. Unoh, K. Hirano, T.
Satoh, M. Miura, Tetrahedron 2013, 69, 4454–4458;
c) M. Zhang, H.-J. Zhang, T. Han, W. Ruan, T.-B. Wen,
J. Org. Chem. 2015, 80, 620–627; d) J. Mo, L. Wang, X.
Adv. Synth. Catal. 2019, 361, 1–8
6
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
��
These are not the final page numbers!

FULL PAPER
asc.wiley-vch.de
Cui, Org. Lett. 2015, 17, 4960–4963; e) S. Warratz, C.
Kornhaaß, A. Cajaraville, B. Niepötter, D. Stalke, L.
Ackermann, Angew. Chem. Int. Ed. 2015, 54, 5513–
5517; Angew. Chem. 2015, 127, 5604–5608; f) E. Kudo,
Y. Shibata, M. Yamazaki, K. Masutomi, Y. Miyauchi, M.
Fukui, H. Sugiyama, H. Uekusa, T. Satoh, M. Miura, K.
Y. Xu, S. Yang, B. Liu, X. Li, Org. Lett. 2018, 20, 2160–
2163; e) G. Zheng, M. Tian, Y. Xu, X. Chen, X. Li, Org.
Chem. Front. 2018, 5, 998–1002; f) P. Hu, Y. Zhang, B.
Liu, X. Li, Org. Chem. Front. 2018, 5, 3263–3266. g) Y.
Xu, X. Yang, X. Zhou, L. Kong, X. Li, Org. Lett. 2017,
19, 4307–4310.
Tanaka, Chem. Eur. J. 2016, 22, 14190–14194; g) G. [16] a) R. J. Mi, J. Sun, F. E. Kühn, M. D. Zhou, Z. Q. Xu,
Jiang, J. X. Li, C. Zhu, W. Wu, H. Jiang, Org. Lett. 2017,
19, 4440–4443; h) C. Yang, X. He, L. Zhang, G. Han, Y.
Zuo, Y. Shang, J. Org. Chem. 2017, 82, 2081–2088; i) P.
Saikia, S. Gogoi, Adv. Synth. Catal. 2018, 360, 2063–
2075; j) T. T. Nguyen, L. Grigorjeva, O. Daugulis,
Angew. Chem. Int. Ed. 2018, 57, 1688–1691; Angew.
Chem. Commun. 2017, 53, 13209–13212; b) J.-H. Duan,
R.-J. Mi, J. Sun, M.-D. Zhou, Org. Chem. Front. 2018, 5,
162–165; c) J.-X. Li, L. Li, M.-D. Zhou, H. Wang, Org.
Chem. Front. 2018, 5, 1003–1007; d) R.-J. Mi, Y.-Z.
Sun, J.-Y. Wang, J. Sun, Z. Q. Xu, M. D. Zhou, Org.
Lett. 2018, 20, 5126–5129.
Chem. 2018, 130, 1704–1707; k) Y. Xu, G. Zheng, X. [17] CCDC-1917189 (2b) contains the supplementary crystal-
Yang, X. Li, Chem. Commun. 2018, 54, 670–673; l) Y. F.
Liang. L. Yang, T. Rogge, L. Ackermann, Chem. Eur. J.
2018, 24, 16548–16552; m) P. Sihag, M. Jeganmohan, J.
Org. Chem. 2019, 84, 2699–2712.
lographic 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.
[18] A. C. Tadd, M. R. Fielding, M. C. Willis, Chem. Com-
mun. 2009, 6744–6746.
[13] For selected reviews, see: a) L. Ackermann, R. Vicente,
Top. Curr. Chem. 2009, 292, 211–229; b) P. B. Arock- [19] P. Manivel, K. Prabakaran, Y. Suneel, S. M. Ghouse,
iam, C. Bruneau, P. H. Dixneuf, Chem. Rev. 2012, 112,
5879–5918; c) B. Li, P. H. Dixneuf, Chem. Soc. Rev.
P. M. Vivek, E. Ubba, I. Pugazhenthi, F.-R. N. Khan,
Res. Chem. Intermed. 2015, 41, 2081–2094.
2013, 42, 5744–5767; d) S. I. Kozhushkov, L. Acker- [20] A. E. Kümmerle, M. M. Vieira, M. Schmitt, A. L. P.
mann, Chem. Sci. 2013, 4, 886–896; e) L. Ackermann,
Acc. Chem. Res. 2014, 47, 281–295; f) V. S. Thirunavuk-
Miranda, C. A. M. Fraga, J. J. Bourgignon, E. J. Barreiro,
Bioorg. Med. Chem. Lett. 2009, 19, 4963–4966.
karasu, S. I. Kozhushkov, L. Ackermann, Chem. Com- [21] a) Y. Xu, X. Zhou, G. Zheng, X. Li, Org. Lett. 2017, 19,
mun. 2014, 50, 29–39; g) S. Ruiz, P. Villuendas, E. P.
Urriolabeitia, Tetrahedron Lett. 2016, 57, 3413–3432.
[14] G. Duarah, P. P. Kaishap, T. Begum, S. Gogoi, Adv.
Synth. Catal. 2019, 361, 654–672.
5256–5259; b) M. Barday, C. Janot, N. R. Halcovitch, J.
Muir, C. Assa, Angew. Chem. Int. Ed. 2017, 56, 13117–
13121; Angew. Chem. 2017, 129, 13297–13301.
[22] E. J. Corey, M. Chaykovsky, J. Am. Chem. Soc. 1965,
87, 1353–1364.
[15] a) C. Wu, J. Zhou, G. He, H. Li, Q. Yang, R. Wang, Y.
Zhou, H. Liu, Org. Chem. Front. 2019, 6, 1183–1188; [23] A. Leggio, R. De Marco, F. Perri, M. Spinella, A.
b) H. Xie, J. Lan, J. Gui, F. Chen, H. Jiang, W. Zeng,
Adv. Synth. Catal. 2018, 360, 3534–3543; c) X. Shi, R.
Wang, X. Zeng, Y. Zhang, H. Hu, C. Xie, M. Wang, Adv.
Synth. Catal. 2018, 360, 4049–4053; d) P. Hu, Y. Zhang,
Liguori, Eur. J. Org. Chem. 2012, 114–118.
Adv. Synth. Catal. 2019, 361, 1–8
7
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Ruthenium(II)-Catalyzed Homocoupling of Weakly Coordi-
nating Sulfoxonium Ylides via CÀ H Activation/Annulations:
Synthesis of Functionalized Isocoumarins
Adv. Synth. Catal. 2019, 361, 1–8
M.-D. Zhou*, Z. Peng, H. Wang*, Z.-H. Wang, D.-J. Hao, L.
Li