Visible-light initiated oxidative cyclization of phenyl propiolates with sulfinic acids to coumarin derivatives under metal-free conditions

Article abstract of DOI:10.1039/c5cc00878f

A visible-light initiated oxidative cyclization of phenyl propiolates with sulfinic acids has been developed. The arylsulfonylation of alkynes was performed at room temperature under metal-free conditions to generate coumarin derivatives with wide functio

Full text of DOI:10.1039/c5cc00878f

View Article Online
View Journal
ChemComm
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: W. Yang, S. Yang,
P. Li and L. Wang, Chem. Commun., 2015, DOI: 10.1039/C5CC00878F.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the Ethical guidelines still
apply. In no event shall the Royal Society of Chemistry be held
responsible for any errors or omissions in this Accepted Manuscript
or any consequences arising from the use of any information it
contains.
www.rsc.org/chemcomm

ChemComm
Page 1 of 4Chemical Communications
Dynamic Article Links ►
View Article Online
DOI: 10.1039/C5CC00878F
Cite this: DOI: 10.1039/c0xx00000x
www.rsc.org/xxxxxx
COMMUNICATION
Visibleꢀlight initiated oxidative cyclization of phenyl propiolates with
sulfinic acids to coumarin derivatives under metalꢀfree conditions
Wenchao Yang,a Shuai Yang,a Pinhua Li,a and Lei Wang*a,b
Received (in XXX, XXX) Xth XXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX
5
DOI: 10.1039/b000000x
a: Trost's work: Palladium-catalyzed synthesis of coumarins
A
visibleꢀlight initiated oxidative cyclization of phenyl
OR
OR
propiolates with sulfinic acids has been developed. The
arylsulfonylation of alkyne was performed at room
temperature under metalꢀfree conditions to generate
Pd2(dba)3 CHCl3
(2.5 mol%)
+
HCO2H, r.t.
COO2C2H5
RO
O
O
RO
OH
10 coumarin derivatives with wide functional group tolerance,
good yields and high regioꢀselectivity.
b: Shi and He's work: Au-(III)-catalyzed intermolecular addition of arenes to alkynes
R2
R2
The coumarin skeleton has been widely found in the structure of
natural products, pharmaceuticals and biologically active
molecules as antiꢀHIV, antiꢀcancer, antiꢀpsoriasis, antiꢀ
15 inflammatory, antiꢀdepressant and antiꢀdiabetic and it has
attracted considerable attention of chemists towards their
synthesis.1,2 Especially in the last decades, preparation of
coumarins has turned into one of the most significant and
fundamental missions in organic synthesis, and many routes have
20 been established.3 As we known, Pechmann condensation has
proven to be one of the most attractive methods.4 Recently,
transitionꢀmetalꢀcatalyzed synthesis of coumarin derivatives has
become the useful strategies. The selected elegant examples,
Trost employed a Pdꢀcatalyzed addition reactions of propargylic
25 esters with phenols to coumarins (Scheme 1a).5 Then, Shi and He
reported a gold(III)ꢀcatalyzed intermolecular addition of arenes to
alkynes within aryl alkynoates to various coumarins (Scheme
1b).6 Very recently, Alper described a novel synthesis of
coumarins through Pdꢀcatalyzed oxidative cyclocarbonylation of
30 unsaturated compounds with CO (Scheme 1c).7 Most recently, we
also developed a Ruꢀcatalyzed reactions for the synthesis of 2,3ꢀ
disubstituted coumarins involving decarboxylative annulations of
αꢀketo acids with internal alkynes.8 In addition, other metalꢀ
catalyzed methods for the direct construction of coumarins have
35 also been proven attractive.9 However, the above transformations
suffer from the requirement of toxic metal, ligand or additive,
extremely limiting their applications in pharmaceutical industry.
Therefore, exploring more convenient, straightforward and green
method for their synthesis is highly desirable.
AuCl3/AgOTf
R1
R1
O
O
O
O
c: Alper's work: Pd-catalyzed cyclocarbonylation of 2-vinylphenols
R1
R1
Pd(OAc)2 (10 mol%)/dppb
CO (100 psi)
R
CH3CN, 110 o
C
R
O
O
OH
d: This work: Visible-light induced arylsulfonylation of alkynes
R2
R2
O
SO2R3
O
Eosin Y (1 mol%)
visible-light irridiation
O
R3
S
R1
R1
+
TBHP, r.t.
OH
O
O
Metal-free system !
Scheme 1. Synthetic strategies for the coumarins synthesis
55
Arylsulfinic acids are versatile and readily available
intermediates in organic synthesis.13 In recent years, many efforts
have been devoted to develop sulfonylation reactions using
sulfinic acids as sulfonylating agents for the construction of
60 sulfoneꢀcontaining
coumarins,15 as materials, and pharmaceuticals.16 Herein, we
report novel visibleꢀlight induced Eosin catalyzed
molecules,14
including
3ꢀsulfonated
a
Y
difunctionalization of alkynes with sulfinic acids via C−C and
C−S bond formation for the synthesis of 3ꢀsulfonated coumarins
65 at room temperature under metalꢀfree conditions (Scheme 1d).
For the optimization of the reaction conditions, 3ꢀ
phenylpropiolate (1a) and 4ꢀmethylbenzenesulfinic acid (2a)
were chosen as the model substrates. Initially, the reaction was
performed in the presence of 1.0 mol% Eosin Y as a photoredox
70 catalyst, 1 equiv of tertꢀbutyl hydroperoxide (TBHP) as an
additive and CH3CN–H2O (1:1 v/v) as solvent at room
temperature under the irradiation of 18 W fluorescent lamp for 12
h. To our delight, the desired coumarin (3a) was obtained in 71%
isolated yield (Table 1, entry 1). When H2O2 was instead of TBHP,
75 the model reaction generated the desired product 3a in 42% yield
(Table 1, entry 2). Other additives such as DTBP, DCP and
PhI(OAc)2 led to poor yield of 3a (Table 1, entries 3−5). Changiꢀ
40
Visibleꢀlight induced organic transformation has emerged as
one of the most flourishing and attractive research area for its
intrinsic characteristics of sustainability and green chemistry in
recent years.10 Although ruthenium, iridium or copper complexes
as photoredox catalysts have been well demonstrated for C−C,
45 C−hetero bonds coupling under visibleꢀlight irradiation,11 organic
dyes compared with metalꢀbased photoredox catalysts show
splendid superiorities, cheapness and nonꢀtoxicity. The organic
dyes including Eosin Y, Fluorescein, Rose Bengal and Eosin B in
visibleꢀlightꢀpromoted organic transformations have proven to be
50 efficient, ecological and economical.12 Nevertheless, it should be
noted that the formation of coumarin and its derivatives has not
been reported through a visibleꢀlight initiation method up to date.
This journal is © The Royal Society of Chemistry [year]
[journal], [year], [vol], 00–00 | 1

ChemComm
Page 2 of 4
View Article Online
DOI: 10.1039/C5CC00878F
Table 1. Optimization of the Reaction Conditions.[a]
Scheme 2. Reaction Scope of Phenyl 3ꢀArylpropiolates.[a]
Ph
O
Ph
O
Ph
O
O
O
O
O
O
O
O
Yield(%)[b]
S
Et
S
Entry
1
Light source
Light[c]
Light[c]
Light[c]
Light[c]
Light[c]
Light[c]
Light[c]
Catalyst
Eosin Y
Additive
TBHP
H2O2
Me
S
71
42
O
Me
O
Me
Me
O
Me
3b, 72%
3c, 70%
3a, 71%
2
Eosin Y
Ph
Ph
Ph
3
Eosin Y
DTBP
DCP
15
O
O
O
O
O
Ph
S
t-Bu
Me
S
i-Pr
S
4
Eosin Y
24
O
O
O
O
Me
O
O
5
Eosin Y
PhI(OAc)2
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
−
N.R.
33
3e, 66%
3d, 74%
3f, 55%
6
[Ru(bpy)3]Cl2·6H2O
Acid Red 87
Eosin Y
Me Ph
Ph
Ph
O
O
O
O
O
O
O
7
16
S
MeO
Me
S
F
S
8
Green LED[d]
Blue LED[e]
−
41
Me
Cl
O
O
O
O
Me
O
O
Me
Me
3h, trace
3g, 65%
9
Eosin Y
N.R.
N.R.
N.R.
N.R.
3i, 69%
Ph
Ph
O
Ph
O
10
11
12
Eosin Y
O
O
O
S
Br
Me
S
I
S
Light[c]
Light[c]
−
O
O
O
O
Me
O
O
Eosin Y
3j, 62%
3l, 65%
3k, 66%
[a]
Reaction conditions: phenyl 3ꢀphenylpropiolate (1a, 0.30 mmol), 4ꢀ
Me Ph
Ph
O
Ph
O
methylbenzenesulfinic acid (2a, 0.60 mmol), photocatalyst (1.0 mol%),
additive (1.0 equiv), CH3CN/H2O (1:1, 1.5 mL) at room temperature under
air for 12 h. [b] Isolated yields. [c] Fluorescent lamp (18 W) was used. [d] Green
LED (530−535 nm) was used. [e] Blue LED (450−455 nm) was used. N.R. =
no reaction.
O
O
O
O
O
S
S
S
O
O
Me
O
Me
Me
O
Me
O
Me
3m, 36%
3m', 36%
3n, trace
3m+3m' (1:1, 72%)
[a] Reaction conditions: 1 (0.30 mmol), 2 (0.60 mmol), Eosin Y (1 mol%),
TBHP (0.30 mmol), CH3CN/H2O (1:1, 1.5 mL), 18 W fluorescent lamp,
at room temperature for 12 h. [b] Isolated yields.
ng photoredox catalyst from Eosin Y to [Ru(bpy)3]Cl2·6H2O or
5
Acid Red 87 could not make better contribution to this
transformation (Table 1, entries 6 and 7). As shown in Table 1,
the application of green LED got lower yield of 3a, but blue LED
failed (Table 1, entries 8 and 9). It is important to note that visible
light, catalyst and additive are essential in the reaction (Table 1,
40
ng groups (F, Cl, Br and F3C) and electronꢀdonating groups (Me)
underwent the transformation well to generate the corresponding
arylsulfonylation products (3o–3t, 3v and 3w) in 58−77% yields.
10 entries 10−12).
With the optimized conditions in hand, we next explored the
45 It also indicated that the reactions are well tolerated for the
substituted groups on the benzene rings of R1 (Scheme 3). The
reaction of 3ꢀphenylpropiolate (1a) with 2ꢀnaphathenesulfinic
acid also afforded the anticipated product 3u in 67% yield. When
R1 was used as alkylꢀsubstitute (Me or nꢀC5H11) in the oxidative
50 cyclization with 2a, no desired product was found. These results
indicated that alkylꢀsubstitutes dramatically affect the reaction.
To gain more mechanistic insights of this reaction, we
performed several control experiments as shown in Scheme 4.
When phenyl 3ꢀphenylpropiolate (1a) was carried out under the
55 standard condition in the absence of 2a, no 4a was observed
(Scheme 4a). In addition, the reaction 2a with prepared 4a could
not transform into 3a under the present conditions (Scheme 4b).
When 2,2,6,6ꢀtetramethylꢀ1ꢀpiperidinyloxy (TEMPO), a radical
scavenger, was added to the system, the oxidative cyclization
60 reaction was completely inhibited (Scheme 4c). In order to verify
the tꢀBuO radical formation, we performed a control experiment
involving in 1a, 2a and TBHP in MeCN/H2O at 90 °C for 12 h
without Eosin Y and visible light irradiation, providing the
desired product 3a in 34% yield (Scheme 4d). The result
65 indicated that TBHP was readily split into tꢀBuO free radical to
perform the reaction under heating conditions.
scope of the oxidative coupling reaction. The results are shown in
Scheme 2. Some representative substituents, including electronꢀ
donating groups, electronꢀwithdrawing groups and halogens,
15 were introduced into phenyl ring of phenyl propiolates (1), and
which were evaluated under standard reaction conditions,
respectively. The arylsulfonylations of phenyl propiolates (1)
without substituent group and containing electronꢀdonating
groups, such as Me, Et, iꢀPr, tꢀBu and Ph on the paraꢀposition of
20 phenyl rings with 4ꢀmethylbenzenesulfinic acid (2a) generated
the corresponding compounds (3a−3f) in moderate to good yields
(55−74%). It should be noted that substrate 1 with a strong
electronꢀdonating substituent (MeO) on the benzene ring could be
reacted with 2a, providing trace amount of the desired product 3h.
25 Meanwhile, substrate 1 with 3,5ꢀdimethyl groups on phenyl ring
underwent the tandem reaction to afford the coumarin 3g in
acceptable yield (65%). Moreover, halogens (F, Cl, Br and I)
attached on the substrate 1 could be well tolerated, giving the
desired products (3i–3l) in 62−69% yields. The reaction of
30 substrate 1 with a methyl group on the metaꢀposition of phenyl
ring reacted and 2a, providing two isomers 3m and 3m' in a ratio
of 1:1 with 72% total yield. However, a significant steric effect
was observed during the reaction of 1 with a methyl group on the
orthoꢀposition of phenyl ring and 2a, and trace amount of 3n was
35 found.
On the basis of above investigation and the literature,17 the
reaction may involve a radical process, along with a sulfonyl
radical addition to alkyne. Thus, a possible mechanism for this
70 photoreaction is proposed in Scheme 5. Initially, a tꢀbutoxyl
radical (A) is produced by a SET from the reaction of excited
state of Eosin Y* with tertꢀbutyl hydroperoxide (TBHP). Then,
On the other hand, a variety of arylsulfinic acids were
examined and the results are shown in Scheme 3. A number of
substituted arylsulfinic acids containing both electronꢀwithdrawiꢀ
2
| Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

Page 3 of 4
ChemComm
View Article Online
DOI: 10.1039/C5CC00878F
Scheme 3. The Scope of Arylsulfinic Acids and Substituent
Scheme 5. Possible reaction mechanism.
Group R1.[a]
In summary, we have developed an efficient and visibleꢀlight
25 initiated, Eosin Yꢀcatalyzed arylsulfonylation of alkynes with
arylsulfinic acids, providing a novel and direct approach to the
preparation of 3ꢀsulfonated coumarins. The reactions generated
the corresponding products in good yields through a tandem
reaction process under metalꢀfree conditions. Further application
30 of this protocol and investigation of detail reaction mechanism
are underway in our laboratory.
[a]
Reaction conditions: 1 (0.30 mmol), 2 (0.60 mmol), Eosin Y (1
mol%), TBHP (0.30 mmol), CH3CN/H2O (1:1, 1.5 mL), 18 W
fluorescent lamp, at room temperature for 12 h. [b] Isolated yields.
This work was financially supported by the National Science
Foundation of China (No. 21372095, 21172092).
Notes and reference
35 Department of Chemistry, Huaibei Normal University, Huaibei, Anhui
5
an abstraction of hydrogen radical from 4ꢀmethylbenzenesulfinic
acid (2a) undergoes to give the corresponding sulfonyl radical (B)
and t-BuOH. Addition of sulfonyl radical B to 3ꢀphenylpropiolate
(1a) delivers the radical intermediate C, which is further
transformed into carbocation intermediate D through an oxidation
a
235000, P R China; E-mail: leiwang@chnu.edu.cn
Tel.: +86-561-380-2069; fax: +86-561-309-0518
b
State Key Laboratory of Organometallic Chemistry, Shanghai Institute
of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032,
40 P R China
† Electronic Supplementary Information (ESI) available: [details of
any supplementary information available should be included here].
See DOI: 10.1039/b000000x/
10 of the radical species C by an Eosin Y+, a radical cation. Finally,
species D is deprotonated, regenerating the aromatic system and
affording the desired 3ꢀsulfonated coumarin product 3a.
1 (a) L. Santana, E. Uriarte, F. Roleira, N. Milhazes and F. Borges, Curr.
45
50
55
60
65
Med. Chem., 2004, 11, 3239; (b) A. Murakami; G. Gao, M. Omura,
M. Yano, C. Ito, H. Furukawa, D. Takahashi, K. Koshimizu and H.
Ohigashi, Bioorg. Med. Chem. Lett., 2000, 10, 59; (c)Y. M. Yang, J.
W. Hyun, M. S. Sung, H. S. Chung, B. K. Kim, W. H. Paik, S. S.
Kang and J. G. Park, Planta Med., 1996, 62, 353; (d) M. A.
Khalmuradov and A. I. Saidkhodzhaev, Chem. Nat. Compd., 1999,
35, 364; (e) F. Borges, F. Roleira, N. Milhazes, L. Santana and E.
Uriarte, Curr. Med. Chem., 2005, 12, 887.
15 Scheme 4. Control experiments.
2 (a) V. RajeshwarRao, K. Srimanth and P. VijayaKumar, Indian J.
Heterocyclic Chem., 2004, 14, 141; (b) J. F. Vasconcelos, M. M.
Teixeira, J. M. BarbosaꢀFilho, M. F. Agra, X. P. Nunes, A. M.
Giulietti, R. RibeiroꢀdosꢀSantos and M. B. P. Soares, Eur. J.
Pharmacol., 2007, 609, 126; (c) X. Peng, G. Damu and C. Zhou,
Curr. Pharm. Des., 2013, 19, 3884; (d) K. V. Sashidhara, A. Kumar,
M. Chatterjee, K. B. Rao, S. Singh, A. K. Verma and G. Palit, Bioorg.
Med. Chem. Lett., 2011, 21, 1937; (e) S. J. Lee, U. S. Lee, W. J. Kim
and S. K. Moon, Mol. Med. Rep., 2011, 4, 337.
3 (a) D. V. Kadnikov and R. C. Larock, Org. Lett., 2000, 2, 3643; (b) J.
Oyamada and T. Kitamura, Tetrahedron, 2006, 62, 6918; (c) G. W.
Kabalka, G. Dong and B. Venkataiah, Tetrahedron Lett., 2004, 45,
5139; (d) T. N. Van, S. Debenedetti, N. D. Kimpe, Tetrahedron Lett.,
2003, 44, 4199; (e) T. Harayama, K. Katsuno. H. Nishiok, M. Fujii,
Y. Nishita, H. Ishii and Y. Kaneko, Heterocycles, 1994, 39, 613; (f) I.
G. Collado, R. HernándezꢀGalán, G. M. Massanet, F. RodríguezꢀLuis
and J. Salvá, Tetrahedron Lett., 1991, 32, 3209.
20
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 3

ChemComm
Page 4 of 4
View Article Online
DOI: 10.1039/C5CC00878F
4 S. Sethna and R. Phadke, Org. React., 1953, 7, 1.
5 B. M. Trost and F. D. Toste, J. Am. Chem. Soc., 1996, 118, 6305.
6 Z. Shi and C. He, J. Org. Chem., 2004, 69, 3669.
press); (g) M. Neumann, S. Füldner, B. König and K. Zeitler, Angew.
Chem., Int. Ed., 2011, 50, 951; (h) A. K. Yadav and L. D. S. Yadav,
Tetrahedron Lett., 2014, 55, 2065.
70
7 (a) J. Ferguson, F. Zeng and H. Alper, Org. Lett., 2012, 14, 5602; (b)
M. AmézquitaꢀValencia and H. Alper, Org. Lett., 2014, 16, 5827.
8 H. Tan, H. Li, J. Wang and L. Wang, Chem. Eur. J., 2015, 21, 1904.
9 Metalꢀcatalyzed synthsis of coumarin and its derivatives see: (a) A.
13 (a) S. G. Modha, V. P. Mehta and E. Van der Eycken, Chem. Soc. Rev.,
2013, 42, 5042; (b) Y. Xi, B. Dong, E. J. McClain, Q. Wang, T. L.
Gregg, N. G. Akhmedov, J. L. Petersen and X. Shi, Angew. Chem. Int.
Ed., 2014, 53, 4657.
5
10
15
20
Seoane, N. Casanova, N. Quiñones, J. L. Mascareñas, and M. Gulías, 75 14 For selected examples, see: (a) M. Ueda and J. F. Hartwig, Org. Lett.,
J. Am. Chem. Soc., 2014, 136, 834; (b) L. Zhang, T. Meng, R. Fan and
J. Wu, J. Org. Chem., 2007, 72, 7279; (c) C. Jia, D. Piao, J. Oyamada,
W. Lu, T. Kitamura and Y. Fujiwara, Science 2000, 287, 1992; (d) X.
Mi, C. Wang, M. Huang, J. Zhang, Y. Wu and Y. Wu, Org. Lett.,
2014, 16, 3356; (e) T. d. A. Fernandes, B. Gontijo Vaz, M. N. Eberlin,
A. J. M. Silva and P. R. R. Costa, J. Org. Chem., 2010, 75, 7085; (f)
B. Schmidt and S. Krehl, Chem. Commun., 2011, 47, 5879; (g) U.
Sharma, T. Naveen, A. Maji, S. Manna and D. Maiti, Angew. Chem.,
Int. Ed., 2013, 52, 12669; (h) X.ꢀH. Cao, X. Pan, P.ꢀJ. Zhou, J.ꢀP. Zou
and O. T. Asekun, Chem. Commun., 2014, 50, 3359; (i) X.ꢀF. Wu, L.
Wu, R. Jackstell, H. Neumann and M. Beller, Chem. Eur. J., 2013, 19,
12245; (j) Y. Yamamoto and N. Kirai, Org. Lett., 2008, 10, 5513; (k)
B. M. Trost, F. D. Toste and K. Greenman, J. Am. Chem. Soc.,2003,
125, 4518; (l) D. Kim, M. Min and S. Hong, Chem. Commun., 2013,
49, 4021; (m) Y. Li, Y. Lu, G. Qiu and Q. Ding, Org. Lett., 2014, 16,
4240.
2010, 12, 92; (b) K. Maloney, J. Kuethe and K. Linn, Org. Lett., 2011,
13, 102; (c) H. Yang, Y. Li, M. Jiang, J. Wang and H. Fu, Chem.-Eur.
J., 2011, 17, 5652; (d) Q. Lu, J. Zhang, Y. Qi, H. Wang, Z. Liu and A.
Lei, Angew. Chem. Int. Ed., 2013, 52, 7156; (e) Q. Lu, J. Zhang, G.
Zhao, Y. Qi, H. Wang and A.ꢀW. Lei, J. Am. Chem. Soc., 2013, 135,
11481; (f) X. Tang, L. Huang, Y. Xu, J. Yang, W. Wu and H. Jiang,
Angew. Chem. Int. Ed., 2014, 53, 4205.
80
85
90
95
15 (a) H. Yoshida, Y. Ito and J. Ohshita, Chem. Commun., 2011, 47, 8512;
(b) T. A. Dias and M. F. Proença, Tetrahedron Lett., 2012, 53, 5235;
(c) W. Wei, J. Wen, D. Yang, M. Guo, Y. Wang, J. You and H.
Wang, Chem. Commun., 2015, 51, 768.
16 (a) M. N. Noshi, A. ElꢀAwa, E. Torres and P. L. Fuchs, J. Am.Chem.
Soc., 2007, 129, 11242; (b) J. N. Desrosiers and A. B. Charette,
Angew. Chem. Int. Ed., 2007, 46, 5955; (c) R. Ettari, E. Nizi, M. E. Di
Francesco, M.ꢀA. Dude, G. Pradel, R. Vicik, T. Schirmeister, N.
Micale, S. Grasso and M. Zappala, J. Med. Chem., 2008, 51, 988.
17 (a) Q. Lu, J. Zhang, G. Zhao, Y. Qi, H. Wang and A. Lei, J. Am.
Chem. Soc., 2013, 135, 11481; (b) J.ꢀY. Luo, H.ꢀL. Hua, Z.ꢀS. Chen,
Z.ꢀZ. Zhou, Y.ꢀF. Yang, P.ꢀX. Zhou, Y.ꢀT. He, X.ꢀY. Liu and Y.ꢀM.
Liang, Chem. Commun., 2014, 50, 1564; (c) W.ꢀT. Wei, R.ꢀJ. Song,
X.ꢀH. Ouyang, Y. Li, H.ꢀB. Li and J.ꢀH. Li, Org. Chem. Front., 2014,
1, 484; (d) X.ꢀH. Ouyang, R.ꢀJ. Song, Y. Li, B. Liu and J.ꢀH. Li, J.
Org. Chem., 2014, 79, 4582.
25 10 For selected reviews on visibleꢀlight induced organic reactions, see:
(a) J. Xuan and W.ꢀJ. Xiao, Angew. Chem. Int. Ed., 2012, 51, 6828;
(b) J. M. R. Narayanam and C. R. J. Stephenson, Chem. Soc. Rev.,
2011, 40, 102; (c) C. K. Prier, D. A. Rankic and D. W. C. MacMillan,
Chem. Rev., 2013, 113, 5322; (d) M. Reckenthäler and A. G.
30
35
40
45
50
55
60
65
Griesbeck, Adv. Synth. Catal., 2013, 355, 2727; (e) J. Xie, H. Jin, P.
Xu and C. Zhu, Tetrahedron Lett., 2014, 55, 36; (f) T. P. Yoon, M. A.
Ischay and J. Du, Nat. Chem., 2010, 2, 527; (g) Y. M. Xi, H. Yi and
A. W. Lei, Org. Biomol. Chem., 2013, 11, 2387; (h) M. N.
Hopkinson, B. Sahoo, J.ꢀL. Li and F. Glorius, Chem. Eur. J., 2014,
20, 3874; (i) S. Fukuzumi, K. Ohkubo, Chem. Sci., 2013, 4, 561.
11 Some examples for the CꢀC and Cꢀhetero bond formations via visibleꢀ
light irradiation using metalꢀbased photoredox catalysts, see: (a) J.
Zoller, D. C. Fabry, M. A. Ronge and M. Rueping, Angew. Chem. Int.
Ed., 2014, 53, 13264; (b) Q.ꢀY. Meng, T. Lei, L.ꢀM. Zhao, C.ꢀJ. Wu,
J.ꢀJ. Zhong, X.ꢀW. Gao, C.ꢀH. Tung and L.ꢀZ. Wu, Org. Lett., 2014,
16, 5968; (c) M. N. Hopkinson, B. Sahoo and F. Glorius, Adv. Synth.
Catal., 2014, 356, 2794; (d) H.ꢀQ. Do, S. Bachman, A. C. Bissember,
J. C. Peters and G. C. Fu, J. Am. Chem. Soc., 2014, 136, 2162; (e) Q.
Qin and S. Yu, Org. Lett., 2014, 16, 3504; (f) Y. Zhang, R. Qian, X.
Zheng, Y. Zeng, J. Sun, Y. Chen, A. Ding and H. Gao, Chem.
Commun., 2015, 51, 54; (g) R. Lin, H. Sun, C. Yang, W. Shen and W.
Xia, Chem. Commun., 2015, 51, 399; (h) A. Noble, S. J. McCarver
and D. W. C. MacMillan, J. Am. Chem. Soc., 2015, 137, 624; (i) A. J.
Musacchio, L. Q. Nguyen, G. H. Beard and R. R. Knowles, J. Am.
Chem. Soc., 2014, 136, 12217; (j) M. Rueping, S. Zhu and R. M.
Koenigs, Chem. Commun., 2011, 47, 8679; (k) N. J. W. Straathof, B.
J. P. Tegelbeckers, V. Hessel, X. Wang and T. Noël, Chem. Sci.,
2014, 5, 4768; (l) A. Baralle, L. Fensterbank, J.ꢀP. Goddard and C.
Ollivier, Chem. Eur. J., 2013, 19, 10809; (m) M. Pirtsch, S. Paria, T.
Matsuno, H. Isobe and O. Reiser, Chem. Eur. J., 2012, 18, 7336; (n)
A. C. HernandezꢀPerez and S. K. Collins, Angew. Chem. Int. Ed.,
2013, 52, 12696.
12 For selected examples using organic dyes as the photoredox catalysts,
see: (a) Y. Pan, S. Wang, C. W. Kee, E. Dubuisson, Y. Yang, K. P.
Loh and C.ꢀH. Tan, Green Chem., 2011, 13, 3341; (b) T. Xiao, L. Li,
G. Lin, Q. Wang, Pi. Zhang, Z. Mao and L. Zhou, Green Chem.,
2014, 16, 2418; (c) Y. Pan, C. W. Kee, L. Chen and C.ꢀH. Tan, Green
Chem., 2011, 13, 2682; (d) H. Liu, W. Feng, C. W. Kee, Y. Zhao, D.
Leow, Y. Pan and C.ꢀH. Tan, Green Chem., 2010, 12, 953; (e) D. P.
Hari, P. Schroll and B. König, J. Am. Chem. Soc., 2012, 134, 2958; (f)
W. Guo, L.ꢀQ. Lu, Y. Wang, Y.ꢀN. Wang, J.ꢀR. Chen and W.ꢀJ. Xiao,
Angew. Chem. Int. Ed., 2015, 54, DOI: 10.1002/anie.201408837 (in
4
| Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]