Visible-Light-Mediated Stereoselective 1,2-Iodoalkylation of Alkynes

Article abstract of DOI:10.1002/adsc.201801636

A visible-light-mediated and photocatalyst/initiator-free addition to alkynes has been developed. An atom transfer radical addition (ATRA) mechanistic afforded a broad scope of valuable iodo-substituted alkenyl derivatives with high E/Z-selectivities, which are versatile intermediates for the synthesis of various tri- and tetra- substituted alkenes. (Figure presented.).

Full text of DOI:10.1002/adsc.201801636

Title: Visible-Light-Mediated Stereoselective 1,2-Iodoalkylation of
Alkynes
Authors: Jie-Jie Liu, Ling Lan, Yu-Ting Gao, Qi Liu, Liang Cheng, Dong
Wang, and Li Liu
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Adv. Synth. Catal. 10.1002/adsc.201801636
Link to VoR: http://dx.doi.org/10.1002/adsc.201801636

10.1002/adsc.201801636
Advanced Synthesis & Catalysis
COMMUNICATION
DOI: 10.1002/adsc.201((will be filled in by the editorial staff))
Visible-Light-Mediated Stereoselective 1,2-Iodoalkylation of
Alkynes
Jie-Jie Liu,a,b Ling Lan,a,b Yu-Ting Gao,a,b Qi Liu,a,b Liang Cheng,a,b,* Dong Wang,a and
Li Liua,b,*
a
Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and
Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese
Academy of Sciences, Beijing 100190, China. E-mails: chengl@iccas.ac.cn (L.C.), lliu@iccas.ac.cn (L.L.)
b
University of Chinese Academy of Sciences, Beijing 100049, China.
Received: ((will be filled in by the editorial staff))
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201######.((Please
delete if not appropriate))
substituted alkenyl derivatives. Atom transfer radical
addition (ATRA) of haloalkanes to alkenes and
alkynes serves as an atom-economical method of
simultaneously forming C-C and C-X bonds, and it
has been recognized as a useful tool in organic
chemistry.[5] However, most ATRA required toxic
and hazardous initiators, peroxides, organotins, and
triethylboron, to name a few. By using light
irradiation, the radical process could be initiated via a
direct energy transfer,[5n-5p] otherwise, a photocatalyst
was always required to activate the reactants which
were not able to absorb the visible light (Scheme 1,
Equation (a)).[1-3] Besides, these methods constantly
employed harsh conditions and lack broad functional
group tolerance. To the best of our knowledge, only
a few examples induced by visible light in the
absence of photocatalyst/initiator was reported to date
(Scheme 1, Equation (b)).[2a] Nonetheless, the
substrates were limited in multihalogen alkanes,
while simple alkyl halides or their C-H precursors
were not applicable. In this regard, we sought to
develop a protocol capable of conducting ATRA with
a broad scope under mild conditions without
photocatalyst or radical initiator. Here we report a
successful realization of a visible-light-mediated
route to 1-iodoalkenyl products from readily
available carbonyls and alkynes via ATRA pathway,[6]
which proceeds under very mild conditions upon
irradiation with blue light-emitting-diodes (LEDs).
This process does not require the use of external
photocatalyst or initiator and the generated products
have proven to be flexible synthons in a variety of
transformations.
Abstract.
A
visible-light-mediated
and
photocatalyst/initiator-free addition to alkynes has been
developed. An atom transfer radical addition (ATRA)
mechanistic afforded a broad scope of valuable iodo-
substituted alkenyl derivatives with high E/Z-
selectivities, which are versatile intermediates for the
synthesis of various tri- and tetra- substituted alkenes.
Keywords: visible-light-mediated; three component;
stereoselective; iodo-substituted alkenes
The demand for synthetic strategies that proceed
under mild and environmental benign conditions is
one of the most pressing problems facing the
synthetic community. Recent decades has witnessed
the blooming of photochemical irradiation as a
powerful approach for challenging transformations.[1]
Typically, photocatalysts which are capable of
engaging in the energy transfer (ET) or single-
electron-transfer (SET) process are heavily employed
in current photochemical reactions. On the other
hand, there are relatively fewer examples of an
organic transformation driven by visible-light without
a photocatalyst.[2] Currently reported visible-light-
induced organic reactions in the absence of
photocatalysts deeply relied on the formation of
electron-donor-acceptor (EDA) complex.[3] Thus, the
development
of
effective
photocatalyst-free
transformations with substrates that were not capable
of forming EDA complex is a challenging goal in
organic synthesis but yet remains largely unexplored.
In the context of our continuous interest in the
chemo- and stereo-selective functionalization of
alkynes,[4] we envisioned that photochemical
reactions induced by visible light could open up mild
and general synthetic approaches to valuable
1
This article is protected by copyright. All rights reserved.

10.1002/adsc.201801636
Advanced Synthesis & Catalysis
5
AgNO3
CH3CN
40
40
35
35
trace
79
83
71
67
66
70
3
ndc
6
Mg(ClO4)2 CH3CN
Mg(ClO4)2 CH3CN
Mg(ClO4)2 CH3CN
10/1
12/1
12/1
11/1
7/1
7de
8ef
9de
10de
11de
12g
13h
14i
15j
Mg(ClO4)2 Acetone 40
Mg(ClO4)2 Toluene 40
Mg(ClO4)2 CH2Cl2
Mg(ClO4)2 CH3CN
Mg(ClO4)2 CH3CN
Mg(ClO4)2 CH3CN
Mg(ClO4)2 CH3CN
40
40
40
40
40
8/1
ndc
ndc
1
33
3
11/1
ndc
a)
General conditions: 1a (0.1 mmol), 2a (1.0 mmol),
additive (30 mmol%), NIS (0.11 mmol, 25 mg) solvent (2
mL), blue LED light (λmax = 444 nm) at argon for 3 hours.
b)
Isolated yields of the E/Z-isomers were given.
E/Z
determined using 1H NMR analysis. nd: Not determined.
10 mol% of Mg(ClO4)2 was used. 2 equiv. of 2a was
used. 5 mol% of Mg(ClO4)2 was used. I2 was used
c)
d)
e)
f)
g)
h)
instead of NIS. TMS-C≡C-I was used instead of NIS.
Reaction time: 15 h. i) Red LED light (λmax = 620 nm) was
Scheme 1. Photochemical ATRA approaches in the
difunctionalization of alkynes.
used. j) Reaction conducted under dark.
The scope of the reaction is shown in Schemes
2-5. A variety of different alkynes, including
terminal aryl alkynes (Scheme 2), terminal alkyl
alkynes (Scheme 3), internal alkynes (Scheme 4) and
various dicarbonyls (Scheme 5) could be applied in
this transformation and afford the corresponding
iodo-substituted alkenes 3-6 in good to excellent
yields (up to 92%). A range of diverse functional
substituents including electron-withdrawing (F, Cl,
Br, CO2Me, CHO, CN, NO2, CO2H) and electron-
donating groups (OMe, OH, Me, Bu-t) were well
tolerated. In all cases, the products were obtained in
excellent stereoselectivities. Interestingly, the E/Z
selectivity could be easily regulated simply by
switching the alkynes. E-iodoalkenes were generated
as the major products for (hetero)aryl substituted
alkynes (Schemes 2, 4-5) while Z-iodoalkenes were
generated predominately with terminal alkyl alkynes
(Scheme 3). The specific stereochemistry was also
confirmed by an X-ray analysis of the coupling
product 4g’, generated from the 4g (For preparation
details and X-ray analysis of 4g’, see SI for details).
This three-component iodoalkylation was also
compatible for a scaled-up experiment, in which the
corresponding iodo-substituted styrene 3a was
furnished in 80% isolated yield with a perfect
diastereoselecitivty (E/Z > 20/1) with only 1 mol% of
the catalyst (Scheme S1, see SI for details).
Initially, the visible-light-mediated coupling of
β-ketoester 1a, phenylacetylene 2a in the presence of
NIS was designed (Table 1). To our delight, the
desired product 3a was generated in 11% yield after 3
hours at room temperature under the irradiation of
blue LED light (λmax = 444 nm) without any addition
of external photosensitizer or initiator (entry 1).
Optimization studies involving the screening of
Lewis acids (entries 2-7), solvents (entries 8-11),
halogenation reagents (entries 12-13) and light
sources (entry 14) led to an significant improvement
in the yield of 3a to 83% isolated yield (E/Z 12/1) by
using Mg(ClO4)2 as the additive and CH3CN as the
solvent (entry 7). On the contrary, a control
experiment performed without irradiation by visible
light was unproductive, indicating that the visible
light irradiation was essential for this transformation
(entry 15).
Table 1. Optimization of the reaction conditionsa
Temp. Yield
Entry Additive
Solvent
E/Zb
(oC)
(%)
1
2
3
4
none
CH3CN
CH3CN
CH3CN
CH3CN
40
11
9/1
Cu(OTf)2
Fe(acac)3
Sc(OTf)3
40
38
10/1
ndc
40
trace
74
40
11/1
2
This article is protected by copyright. All rights reserved.

10.1002/adsc.201801636
Advanced Synthesis & Catalysis
Scheme 3. Substrate scope for terminal alkyl alkynesa
General conditions: a) 1a (0.1 mmol, 1.0 equiv, 15 µL),
alkynes 2 (5 equiv), Sc(OTf)3 (20 mmol%, 9.8 mg), NIS
(1.1 eq, 25 mg), CH3CN (2 mL), blue LED light (λmax =
444 nm) at argon for 24 h. Isolated yields of the E/Z-
isomers were given.
General Conditions: a) 1a (0.1 mmol, 15 µL), terminal aryl
alkynes 2 (2 equiv), Mg(ClO4)2 (10 mol%, 2.3 mg), NIS
Scheme 4. Substrate scope for internal alkynesa
(1.1 eq, 25 mg), CH3CN (2 mL), blue LED light (λmax
=
444 nm) at argon for 3 h. Isolated yields of the E/Z-isomers
were given. b) NMR yield. c) Reaction time: 12h.
Scheme 2. Substrate scope for aryl alkynesa
General conditions: a) 1a (0.1 mmol, 1.0 equiv, 15 µL),
alkynes 2 (5 equiv), Sc(OTf)3 (20 mmol%, 9.8 mg), NIS
(1.1 eq, 25 mg), CH2Cl2 (2 mL), blue LED light (λmax
444 nm) at argon for 12 h. Isolated yields of the E/Z-
isomers were given. b) 10 mL of CH2Cl2 was used as
=
General Conditions: a) carbonyl (0.1 mmol, 1.0 equiv),
alkyne 2a (2 equiv, 22 µL), Mg(ClO4)2 (10 mol%, 2.3 mg),
NIS (1.1 eq, 25 mg), CH3CN (2 mL), blue LED light (λmax
= 444 nm) at argon for 3 h. Isolated yields of the E/Z-
3
solvent, 24 h. c) 10 mL of CHCl3 was used as solvent, 24 h.
This article is protected by copyright. All rights reserved.

10.1002/adsc.201801636
Advanced Synthesis & Catalysis
d)
isomers were given. b) NMR yield. c) 5 mmol scale, 16 h.
Reaction time: 12h.
Scheme 5. Substrate scope for different dicarbonylsa
The application potential of the method was
further explored by converting the terminal iodo-
group by various reactions (Scheme 6). Thus, iodo-
substituted alkene 5a was subjected to Heck coupling
(Equation (a)), Sonogashira reaction (Equations (b))
and CuI catalyzed C-N amination (Equation (c)) to
give the conjugated unsaturated ester 7, phenyl enyne
8 and N-vinyl pyrrole 9, respectively. A selective
deiodination of 3a with Zn/HOAc afforded
disubstituted alkene 10 (Equation (d)). The latter
compound was further converted via Pd/C-catalyzed
hydrogenation to afford phenethyl ketoester 11
(Equation (e)).
Iodonaphthalene (NpI) and its
derivatives are important building blocks in organic
synthesis, pharmaceutical industry and material
sciences.[7] The α-vinyl ketoester 3a and 6a easily
underwent a Friedel-Crafts acylation to afford the
fused 1-iodonaphthalene 12 and 13 smoothly
(Equation (f)). Interestingly, when 6l was subjected
to
a
similar
acylation,
iodo-substituted
naphthalenepropanoic acid 14 was isolated in good
yields (Equation (g)). An arenium cation was
proposed to be involved in this fragmentation in the
presence of AlCl3 (see SI, Scheme S2).[8] Multi-
substituted naphthalenepropanoic acid consist an
important structural motif in marine natural products
Scheme 6. Various transformations pertaining to the iodo-
substituted alkenes.
Several control experiments for the elucidation
of mechanism was summarized in Scheme 7. When
the reaction of 2-allyl malonate 1q with alkyne 2a
was performed under the standard reaction conditions,
the expected 1,2-iodoalkylation product was not
observed (equation (a)). Instead an iodomethyl
substituted cyclopentene 6s was isolated in 64 %
yield, which strongly consisted with a radical
pathway. In the presence of a radical scavenger
(Butylated hydroxytoluene (BHT) or (2,2,6,6-
and
pharmaceutical
candidates.[9]
of iodo-substituted
This
straightforward synthesis
naphthalenepropanoic acid will certainly benefit the
chemistry community.
tetramethylpiperidin-1-yl)oxidanyl
(TEMPO))
(Equations (b-c)), only trace of the desired products
3a was formed, while the adduct 15 was isolated,
indicating an involvement of ketoester radical
intermediate (see SI for details). Furthermore, we
have successfully isolated α-iodo intermediate 16 in
the absence of alkyne. As expected, irradiation of the
α-iodo intermediate 16 with additional alkyne 2a did
afford the desired product 6h in a comparable yield
(86%). A complete shutdown of reactivity was
observed without visible light or in the presence of
TEMPO, thus suggesting that 16 might be a possible
intermediate (equations (d-f)). We speculated that
the C-I bond dissociation might be the crucial step,
thus we prepared its bromo analogue 16-Br, and
subjected it to the standard reaction conditions. As
expected, no reaction occurred, probably due to the
high dissociation energy required for the C-Br bond
(see SI for details). On the other hand, 1-hydroxy-2-
naphthoate 18, formed by decomposition of 17, was
1
also isolated (see SI for details). The H NMR
analysis of the crude mixture of the in situ generated
4
This article is protected by copyright. All rights reserved.

10.1002/adsc.201801636
Advanced Synthesis & Catalysis
16 under blue LED irradiation or dark condition
further supported that the direct photolysis of the 16
was the first step to induce the radical process
(equations (g-h) and Figure S3). And the UV-visible
absorption of the 1i, 2a, 16 and 6h were also
conducted to prove this process (Figure S5).
the radical process (a quantum yield of 11.6 was
measured and again supported this chain reaction
pathway, see SI for details). The excellent E-
configuration control may be ascribed to steric
hindrance that A would like to approach the radical
from less steric direction (for related examples and
study, see ref 11).
Scheme 8. Hypothetical cascade radical pathway.
In summary, we have developed a novel visible-
light-mediated intermolecular ATRA coupling of
carbonyls, alkynes and NIS under mild conditions
without external photocatalyst or radical initiator.
The generated functionally diverse iodo-substituted
alkenyl derivatives may be of interest in
pharmaceutical or material sciences as they have
proven to be valuable building blocks in a variety of
transformations, some of which were demonstrated in
this work. Further applications of this mild ATRA
transformation is currently on-going in our lab and
will be reported in due courses.
Experimental Section
Scheme 7. Investigation of the Mechanism.
Representative procedure for the three component
coupling:
Based on previous investigations[10] and our
present data, the following reaction mechanism is
proposed (Scheme 8). The reaction was initiated by
visible light irradiation/Lewis acid catalysis,
generating α-carbonyl radical B with the release of
iodide radical. An intermolecular addition of the α-
carbonyl radical B with alkynes afforded the γ-
carbonyl vinyl radicals C (R1 = Alkyl) and D (R1 =
Aryl), respectively. The preferred Z-selectivity for
alkyl alkynes likely depended on the relative stability
of the E/Z-intermediates, with E-C being more stable
to give the Z-iodo alkenes as the major products.
When (hetero)aryl alkynes were used, the generated
radicals D would likely isomerize to a more stable π-
radical E,[11] which subsequently reacted with α-iodo
dicarbonyl intermediate A to deliver the final
products while releasing the radical B to regenerate
For terminal aryl alkynes: Mg(ClO4)2 (0.01 mmol,
2.3 mg), NIS (0.11 mmol, 25 mg) and aromatic alkynes 2
(0.2 mmol, if solid) were placed in an oven-dried Schlenk-
tube. The tube was evacuated and filled with argon for four
times. A solution of β-Ketocarbonyl 1 (0.1 mmol) and
aromatic alkynes 2 (0.2 mmol, if liquid) in CH3CN (2 mL)
was added at RT. The reaction mixture was irradiated
under 9.6 W blue LEDs (λmax = 444 nm) at RT and stirred
for 3 hours. The resulting mixture was directly subjected to
flash column chromatography on silica gel to afford the
desired products 3, 6.
For the procedure of internal and aliphatic alkynes,
detailed experimental procedures, characterization data,
1
mechanism study, copies of H and 13C NMR spectra, see
SI.
CCDC 1845340 (3a), 1845341 (6h), 1845342 (5a),
1845343 (4g’) and 1845344 (14) contain the
5
This article is protected by copyright. All rights reserved.

10.1002/adsc.201801636
Advanced Synthesis & Catalysis
supplementary crystallographic data for this paper. These
data can be obtained free of charge from The Cambridge
Jensen, W. H. Urry, J. Am. Chem. Soc. 1947, 69, 1100-
1105. p) M. S. Kharasch, B. M. Kuderna, W. Urry, J.
Org. Chem. 1948, 6, 895-902.
Crystallographic
Data
Centre
via
www.ccdc.cam.ac.uk/data_request/cif
[6] For selected examples with external halogenation
reagents, see: a) Z. Chen, J. Li, H. Jiang, S. Zhu, Y. Li,
C. Qi, Org. Lett. 2010, 12, 3262-3265; b) Y. Nishimoto,
H. Ueda, M. Yasuda, A. Baba, Chem. -Eur. J. 2011, 17,
11135-11138; c) Z. Hang, Z. Li, Z.-Q. Liu, Org. Lett.
2014, 16, 3648-3651.
Acknowledgements
This work was supported by the National Key R&D Program of
China (2016YFA0602900 and 2017YFA0208100), National
Natural Science Foundation of China (91853124, 21778057 and
21420102003) and Chinese Academy of Sciences.
[7] a) G. Kothandaraman, D. W. Pratt, J. Chem. Phys.
1975, 63, 3337-3348; b) M. F. Lecompte, S.
Krishnaswamy, K. G. Mann, M. E. Nesheim, C. Gitler,
J. Biol. Chem. 1987, 262, 1935-1937; c) Y. Raviv, Y.
Salomon,C. Gitler, T. Bercovici, Proc. Natl. Acad. Sci.
U.S.A. 1987, 84, 6103-6107; d) L. Herrera, P. Barrio, I.
Ibanez, R. Roman, N. Mateu, S. Fustero, Org. Lett.
2016, 18, 4722-4725.
References
[1] a) N. A. Romero, D. A. Nicewicz, Chem. Rev. 2016,
116, 10075-10166; b) C. K. Prier, D. A. Rankic, D. W.
C. MacMillan, Chem. Rev. 2013, 113, 5322-5363; c) J.
W. Tucker, C. R. J. Stephenson, J. Org. Chem. 2012,
77, 1617-1622; d) J. Xuan, W. Xiao, Angew. Chem. Int.
Ed. 2012, 51, 6828-6838; e) T. P. Yoon, M. A. Ischay,
J. Du, Nat. Chem. 2010, 2, 527-532; f) Arceo, E.;
Montroni E.; Melchiorre, P. Angew. Chem. Int. Ed.
2014, 53, 12064-12068; g) T. Yajima, M. Ikegami,
Eur. J. Org. Chem. 2017, 2126-2129.
[8] Y. Zhang, X. Tong, Org. Lett. 2017, 19, 5462-5465.
[9] a) M. Gao, H. Qi, J. Li, H. Zhang, J. Zhang, J. Wang,
W. Xiang, J. Asian Nat. Prod. Res. 2017, 19, 930-934;
b) S. Liu, Irbesartan pharmaceutical composition,
application thereof to biological medicine, Chinese
Patent CN105859547-A, June 7, 2016.
[2] a) J. F. Franz, W. B. Krausab, K. Zeitler, Chem.
Commun. 2015, 51, 8280-8283; b) W. Q. Ji, H. Tan, M.
Wang, P. H. Li, L. Wang, Chem. Commun. 2016, 52,
1462-1465; c) H. Wang, Y. Cheng, S. Yu, Sci China
Chem. 2016, 59, 195-198; d) P. Liu, W. B. Liu, C. J. Li,
J. Am. Chem. Soc. 2017, 139, 14315-14321.
[10] a) P. J. Kropp, N. J. Pienta, J. Org. Chem. 1983, 48,
2084-2090; b) K. Usami, Y. Nagasawa, E. Yamaguchi,
N. Tada, A. Itoh, Org. Lett. 2016, 18, 8-11.
[11] a) K Wang, L.-G. Meng, L. Wang, J. Org. Chem.
2016, 81, 7080-7087; b) K. C. Sproul, W. A. Chalifoux,
Org. Lett. 2015, 17, 3334-3337; c) N. Iqbal, J. Jung, S.
Park, J. E. Cho, Angew. Chem., Int. Ed. 2014, 53, 539-
542.
[3] a) A. Vogler, H. Kunkely, Coord. Chem. Rev. 2000,
208, 321-329; Wang, Y.; b) J. Wang, G. Li, G. He, G.
Chen, Org. Lett. 2017, 19, 1442-1445.
[4] a) Y.-X. Li, Q.-Q. Xuan, L. Liu, D. Wang, Y.-J. Chen,
C.-J, Li, J. Am. Chem. Soc. 2013, 135, 12536-12539; b)
J. J. Liu, H. Y. Huang, L. Cheng, Q. Liu, D. Wang, L.
Liu, Org. Biomol. Chem. 2018, 16, 899-903.
[5] a) B. M. Trost, Science 1991, 254, 1471-1477; b) M. S.
Kharasch, P. S. Skell, P. Fisher, J. Am. Chem. Soc.
1948, 70, 1055-1059; c) M. S. Kharasch, E. V. Jensen,
W. H. Urry, Science. 1945, 102, 128-128. d) D. P.
Curran, E. Bosch, J. Kaplan, M. Newcomb, J. Org.
Chem. 1989, 54, 1826-1831; e) D. P. Curran , C.-T.
Chang, J. Org. Chem. 1989, 54, 3140-3157; f) D. P.
Curran, M.-H. Chen, E. Spleterz, C. M. Seong, C.-T.
Chang, J. Am. Chem. Soc. 1989, 111, 8872-8878; g) D.
P. Curran, C. M. Seong, J. Am. Chem. Soc. 1990, 112,
9401-9403; h) D. P. Curran, J. Tamine, J. Org. Chem.
1991, 56, 2746-2750; i) D. P. Curran, D. Kim,
Tetrahedron. 1991, 47, 6171-6188; j) D. P. Curran, D.
Kim, C. Ziegler, Tetrahedron. 1991, 47, 6189-6196; k)
H. Yorimitsu, T. Nakamura, H. Shinokubo, K. Oshima,
J. Org. Chem. 1998, 63, 8604-8605; l) H. Yorimitsu, T.
Nakamura, H. Shinokubo, K. Oshima, K. Omoto, H.
Fujimoto, J. Am. Chem. Soc. 2000, 122, 11041-11047;
m) H. Yorimitsu, H. Shinokubo, S. Matsubara, K.
Oshima, K. Omoto, H. Fujimoto, J. Org. Chem. 2001,
66, 7776-7785. n) T. Yajima, H. Nagano, Org. Lett.
2007, 9, 13, 2513-2515. For light-induced classic
Kharasch reactions, see: o) M. S. Kharasch, E. V.
6
This article is protected by copyright. All rights reserved.

10.1002/adsc.201801636
Advanced Synthesis & Catalysis
COMMUNICATION
Visible-Light-Mediated Stereoselective 1,2-
Iodoalkylation of Alkynes
Adv. Synth. Catal. Year, Volume, Page – Page
Jie-Jie Liu, Ling Lan, Yu-Ting Gao, Qi Liu, Liang
Cheng,* Dong Wang, and Li Liu*
7
This article is protected by copyright. All rights reserved.