Visible-Light-Mediated Rose Bengal-Catalyzed α-Hydroxymethylation of Ketones with Methanol

Article abstract of DOI:10.1002/adsc.201800467

A visible-light-mediated α-hydroxymethylation of ketones using methanol as the hydroxymethylating reagent has been developed. Using 1 mol% rose bengal as the photosensitizer and air as the green oxidant, the reactions proceeded smoothly at room temperature. Experimental studies indicate the reaction proceeded via a radical pathway. (Figure presented.).

Full text of DOI:10.1002/adsc.201800467

Title: Visible-Light-Mediated Rose Bengal-Catalyzed α-
Hydroxymethylation of Ketones with Methanol
Authors: Jingya Yang, Dongtai Xie, Hongyan Zhou, Shuwen Chen,
Jiaokui Duan, Congde Huo, and Zheng Li
This manuscript has been accepted after peer review and appears as an
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published online in Early View as soon as possible and may be different
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To be cited as: Adv. Synth. Catal. 10.1002/adsc.201800467
Link to VoR: http://dx.doi.org/10.1002/adsc.201800467

10.1002/adsc.201800467
Advanced Synthesis & Catalysis
COMMUNICATION
DOI: 10.1002/adsc.201((will be filled in by the editorial staff))
Visible-Light-Mediated Rose Bengal-Catalyzed α-
Hydroxymethylation of Ketones with Methanol
Jingya Yang,a* Dongtai Xie,a Hongyan Zhou,b Shuwen Chen,a Jiaokui Duan,a Congde
Huo,a and Zheng Lia
a
College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
Fax: (+86)-931-7972-626; e-mail: yangjy@nwnu.edu.cn
College of Science, Gansu Agricultural University, Lanzhou 730070, China
b
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))
functionalization of ketones with methanol, the
Abstract. A visible-light-mediated α-hydroxymethylation
of ketones using methanol as the hydroxymethylating transition-metal catalyzed direct α-methylation[11] and
sodium iodide catalyzed direct α-methoxylation[12]
reagent has been developed. Using 1 mol% rose bengal as
the photosensitizer and air as the green oxidant, the
reactions proceeded smoothly at room temperature.
Experimental studies indicate the reaction proceeded via a
radical pathway.
have been successfully developed (Scheme 1a).
However, the challenging α-hydroxymethylation of
ketones with methanol has not yet been reported.
Hence, exploring an environmentally benign and
practical
protocol
for
the
α-C(sp3)–H
Keywords: hydroxymethylation; ketones; methanol;
photocatalysis; radical reactions
hydroxymethylation of ketones utilizing methanol as
the hydroxymethylating reagent is highly desirable
and of great importance.
The hydroxymethyl group is not only widely found in
natural products and bioactive molecules,[1] but it is
of great importance in organic synthesis due to the
broad range of synthetic transformations it can
undergo.[2] Hydroxymethylation reactions, one of the
most important types of C–C bond-forming reactions
and useful one-carbon extension methods in organic
synthesis, is the most straightforward approach for
introducing
hydroxymethyl
groups.
Hence,
hydroxymethylation reactions have been extensively
studied, and some significant achievements have been
made.[3] However, few methods for the direct α-
hydroxymethylation of ketones have been developed.
Formaldehyde
is
the
most
common
hydroxymethylating reagent for reactions involving
either a direct aldol reaction of ketones[4] or a
Mukaiyama aldol reaction of silicon enolates.[5]
Scheme 1. α-C(sp3)–H Functionalization of ketones with
methanol.
Methanol, the simplest aliphatic alcohol, is
abundant, inexpensive, readily available, and
biodegradable. The utilization of methanol as a
“green” and “renewable” C1 source is of great
importance in organic synthesis; thus, significant
advancements in the use of this reagent have been
Visible-light photocatalysis has emerging as a
green and powerful technique for organic synthesis in
recent years.[13] Moreover, this technique often
employs molecular oxygen, the “greenest” and
cheapest oxygen source, to achieve challenging
transformations in a green manner.[14]
Previously, we reported the visible-light promoted
α-hydroxylation of α-methylene ketones.[15] As part
of our continuing study on visible-light mediated
made
in
recent
years.[6]
However,
hydroxymethylation reactions that use methanol as
the C1 source are limited to C(sp2)–H bonds of
heteroarenes,[7] imines,[8] allenes[9] and dienes.[10]
Therein, transition-metal catalysts or a large excess of
peroxides were needed. As for α-C(sp3)–H
1
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10.1002/adsc.201800467
Advanced Synthesis & Catalysis
reactions, herein we report a novel, visible-light
photocatalytic strategy for the direct α-C(sp3)–H
hydroxymethylation of ketones with methanol under
aerobic and mild conditions (Scheme 1b).
20
21
rose bengal
rose bengal
‒
K2CO3
‒
K2CO3
61,[i] 67,[j] 42[k]
n.r.
trace
22
[a]
General conditions: 1a (0.3 mmol), methanol (1 mL),
We commenced this study using propiophenone
(1a) as a model substrate to optimize the reaction
conditions, and the results are shown in Table 1.
Generally, the model reaction was carried out in the
presence of 1 mol% of a photosensitizer under the
irradiation of a 5 W white LED in methanol while
exposed to air. First, a variety of photosensitizers
were investigated in conjunction with K2CO3 as the
base (entries 1–7). Some of the photosensitizers
provided desired α-hydroxymethyl ketone 2a with
tolerable results, but organic dye rose bengal gave the
highest yield (53%, entry 5). Then, a series of
inorganic and organic bases were screened (entries 8–
15), but the results they provided were inferior to
those provided by K2CO3. Furthermore, using an
oxygen balloon instead of air gave a similar yield
(entry 16). Further studies showed that reducing or
increasing the amount of K2CO3 resulted in a
diminished yield of 2a (entry 17). On the other hand,
the desired product was obtained in 49% and 40%
yield when the reaction was conducted under the
irradiation of a 5 W blue LED and 5 W green LED,
respectively (entry 18). Moreover, using a 7 W white
LED instead of a 5 W white LED increased the yield
slightly (entry 19). Interestingly, adding H2O was
beneficial for the model reaction (entry 20). Finally,
control studies revealed that this reaction did not
occur in the absence of base, and only a trace amount
of the product was detected in the absence of the
photocatalyst (entries 21 and 22).
photocatalyst (1 mol %), base (1 equiv), rt, air, irradiated
by a 5 W white LED for 36 h. [b] Isolated yield. [c] Oxygen
[e]
balloon instead of air. [d] K2CO3 loading was 0.5 equiv.
K2CO3 loading was 1.5 equiv. [f] A 5 W blue LED was used.
[g] A 5 W green LED was used. [h] A 7 W white LED was
[k]
used. [i] With 0.1 mL of H2O. [j] With 0.3 mL of H2O.
With 0.5 mL of H2O. TMG = tetramethylguanidine. n.r. =
no reaction occurred.
Table 2. Scope of substrate.[a][b]
Table 1. Optimization of the Reaction Conditions.[a]
Entry Photosensitizer
Base
Yield [%][b]
1
Ru(bpy)3Cl2·6H2O K2CO3
49
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Ir(ppy)3
eosin Y
eosin B
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K3PO4
Cs2CO3
7
39
trace
53
trace
36
rose bengal
rhodamine B
fluorescein
rose bengal
rose bengal
rose bengal
rose bengal
rose bengal
rose bengal
rose bengal
rose bengal
rose bengal
rose bengal
rose bengal
rose bengal
48
46
NaHCO3 n.r.
K2HPO4
KOtBu
DBU
TMG
DABCO n.r.
K2CO3
K2CO3
K2CO3
K2CO3
n.r.
43
trace
34
[a]
Reaction conditions: 1 (0.3 mmol), methanol (1 mL),
rose bengal (1.0 mol %), K2CO3 (1.0 equiv), H2O (0.3 mL),
[b]
rt, air, under irradiation of a 7 W white LEDs for 36 h.
Isolated yield.
55[c]
32,[d] 44[e]
49,[f] 40[g]
56[h]
With the optimum reaction conditions in hand, the
scope of ketones was evaluated (Table 2). Other than
4-methoxypropiophenone, which gave corresponding
2
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10.1002/adsc.201800467
Advanced Synthesis & Catalysis
product 2d in low yield due to its poor solubility in
piperidinyloxy) was added to the system, the reaction
was completely inhibited, and only a trace amount of
product 2a was detected, suggesting the reaction
might proceed via a radical pathway (Scheme 3, eq 3).
Additionally, 1,1-diphenylethylene was used as
radical-trapping reagent to trap possible radical
intermediates (Scheme 3, eq 4). Fortunately, the
possible carbon radical formed in situ was captured
by 1,1-diphenylethylene, with the product detected by
HRMS analysis (see Supporting Information). On the
other hand, when BHT (2,6-di-t-butyl-p-cresol) was
added to the reaction mixture under the standard
conditions, the oxidative products BHT-OOH (3) and
BHT-OH (4) were obtained in addition to 2a in yields
of 17%, 60% and 15%, respectively (Scheme 3, eq 5).
The result suggests singlet oxygen, 1O2, was
methanol, propiophenone derivatives with either
electron-donating
or
electron-withdrawing
substituents on their phenyl ring were efficiently
converted to the desired products in good yields (2a–
2c and 2e–2l). The results indicate that the electronic
effect of the substituents on the benzene ring is small.
The substrate scope was further extended to a series
of ketones with longer alkyl chains (R2 = Et, Pr,
phenethyl), which were also well-tolerated and
afforded the corresponding products (2m–2q) in
moderate
yields.
Furthermore,
1,2,3,4-
tetrahydronaphthalene propanone (2r) and 1,2,3,4-
tetrahydronaphthalene butanone (2s) were suitable
substrates for this protocol. Notably, the heteroaryl
thiophene propanones were found to be promising
substrates
and
provided
corresponding
α-
generated during the reaction.[16] This was further
1
hydroxymethylated products 2t and 2u in good yields. confirmed by adding O2 scavenger DABCO, and
However, α-methine ketone 1v gave corresponding
hydroxymethylated product 2v in low yield, which is
possibly caused by its larger steric hindrance.
under these conditions, the reaction was almost
completely inhibited (Scheme 3, eq 6). In addition,
we speculate that H2O prevents the dehydration of the
target product, which would lead to byproducts. This
hypothesis was confirmed by the water-free reaction
starting from 2a, which afforded methoxymethylation
product 5a in 28% isolated yield (Scheme 3, eq 7).
Compound 5a was likely formed by a dehydration-
conjugate addition sequence.
In addition, octan-2-one and 4-phenylbutan-2-one
were tested under standard conditions. Unfortunately,
they leaded to incomplete transformations and gave a
complex mixture. This accounts for the fact that
acidity of the α-C–H bond of ketones is crucial.
We also performed the reactions of propiophenone
(1a) with ethanol, propanol or isopropanol,
respectively. Ethanol gave the desired product as a
mixture of stereoisomers in 12% yield (see
Supporting Information). Propanol and isopropanol
did not react at all. We speculate that this may be the
cause of steric hindrance.
To further showcase the synthetic utility of the
established method, a gram-scale experiment of 1a
was performed under the standard conditions. As
shown in Scheme 2, the reaction proceeded well and
furnished the product 2a in 52% isolated yield.
Scheme 2. Gram-scale experiment.
To explore the possible mechanism of this reaction,
a series of control experiments were conducted
(Scheme 3). Initially, several reactions were carried
out under conditions in which one parameter was
changed/added to the standard conditions (Scheme 3,
eqs 1–7). First, no reaction occurred at all when 1a
was stirred in the dark, which shows that visible light
is essential to the present transformation (Scheme 3,
eq 1). Moreover, only a trace amount of product 2a
was detected when the model reaction was conducted
under an argon atmosphere, which indicates that air is
required (Scheme 3, eq 2). Next, when radical
Scheme 3. Control experiments.
In addition, the kinetic isotopic effect (KIE)
experiments were also conducted (Scheme 4). When
two parallel reactions were carried out with methanol
inhibitor
TEMPO
(2,2,6,6-tetramethyl-1-
3
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10.1002/adsc.201800467
Advanced Synthesis & Catalysis
and d4-methanol as the substrates respectively to
determine the kinetic isotopic effect, a value of KH/KD
= 1.1 was obtained (Scheme 4, a). We further did an
intermolecular competitive reaction of methanol and
d4-methanol with 1a and a KIE value of KH/KD = 1.4
was observed (Scheme 4, b). These results suggest
that the C−H cleavage of methanol was probably not
involved in the rate-determining step.
Scheme 5. Proposed reaction mechanism.
To illustrate the application of the products, α-
hydroxymethyl ketones, some functionalizations of
the hydroxymethyl group of 2a were implemented
(Scheme 6). Under literature conditions,[19] 2a was
smoothly converted to chloro derivative 6a and enone
7a which are useful synthetic intermediates.
Scheme 4. Kinetic isotopic effect experiments.
Based on the experimental results and the literature
d
precedent,[7 ,16,17] we proposed a reaction mechanism
for the α-hydroxymethylation of ketones (Scheme 5).
First, rose bengal (RB) is excited to its excited state
species, RB*, under visible-light irradiation. Then,
excited state RB* activates molecular oxygen to
singlet oxygen, 1O2, by energy transfer, and it returns
to its ground state (RB). Simultaneously, ketone 1a is
converted to enol 1a’ by enolization in the presence
of a base. Then, the generated singlet oxygen reacts
with enols 1a’ rapidly to generate the α-carbon
radical A and hydroperoxide radical B (after
superoxide formation and protonation). In this step,
another possibility is that the enol/single oxygen pair
might also undergo a sequence of electron transfer
and proton transfer leading to an overall hydrogen
transfer.[18] Subsequently, hydroperoxide radical B
abstracts a hydrogen from methanol to produce
hydroxymethyl radical C with the concomitant
release of hydrogen peroxide. Finally, the
hydroxymethyl radical C combines the carbon radical
A to afford desired product 2a.
Scheme 6. Transformations of α-hydroxymethyl ketone 2a.
In conclusion, we have developed a visible-light
mediated
method
for
the
α-C(sp3)–H
hydroxymethylation of ketones using methanol as the
C1 source. The present work is essentially different
from the previously reported α-methylation and α-
methoxylation reactions of ketones with methanol.
The reaction likely involves a visible-light-induced
radical process. This is also the first report for the
hydroxymethylation reaction of a C(sp3)–H bond
using methanol as the hydroxymethylating reagent. A
series of α-methylene ketones are well tolerated in the
developed method, and they afforded the desired
products in moderate to good yields. Visible light,
atmospheric oxygen, methanol and mild conditions
meet the requirements of green chemistry, which
make this protocol environmentally friendly.
Experimental Section
General procedure for ɑ-hydroxymethylation of
ketones
4
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10.1002/adsc.201800467
Advanced Synthesis & Catalysis
Ketones 1 (0.3 mmol), rose bengal (3.1 mg, 1 mol%),
K2CO3 (41.5 mg, 1.0 equiv), MeOH (1 mL) and H2O (0.3
mL) were added into a 5 mL glass vial. The reaction
mixture was stirred at room temperature under 7 W white
LED irradiation and ambient air (connected to air with an
injection needle) for 36 h. After completion of the reaction
(monitored by TLC), the reaction solution was
concentrated under reduced pressure and the reaction
mixture was purified by column chromatography on silica
gel (PE:EtOAc = 5:1) to afford pure product 2.
J. Mlynarski, Tetrahedron Lett. 2010, 51, 4088‒4090; d)
N. Mase, A. Inoue, M. Nishio, K. Takabe, Bioorg. Med.
Chem. Lett. 2009, 19, 3955‒3958; e) J. Casas, H.
Sundén, A. Córdova, Tetrahedron Lett. 2004, 45,
6117‒6119.
[5] a) H. Miyamura, A. Sonoyama, D. Hayrapetyan, S.
Kobayashi, Angew. Chem. 2015, 127, 10705‒10709;
Angew. Chem. Int. Ed. 2015, 54, 10559‒10563; b) M.
Kokubo, C. Ogawa, S. Kobayashi, Angew. Chem. 2008,
120, 7015‒7017; Angew. Chem. Int. Ed. 2008, 47,
6909‒6911; c) M. Kokubo, S. Kobayashi, Synlett 2008,
1562‒1564; d) S. Kobayashi, T. Ogino, H. Shimizu, S.
Ishikawa, T. Hamada, K. Manabe, Org. Lett. 2005, 7,
4729‒4731; e) S. Ishikawa, T. Hamada, K. Manabe, S.
Kobayashi, J. Am. Chem. Soc. 2004, 126, 12236‒12237;
f) K. Manabe, S. Ishikawa, T. Hamada, S. Kobayashi,
Tetrahedron 2003, 59, 10439‒10444; g) S. Kobayashi,
I. Hachiya, J. Org. Chem. 1994, 59, 3590‒3596; h) S.
Kobayashi, Chem. Lett. 1991, 20, 2187‒2190.
Acknowledgements
We thank the National Nature Science Foundation of China
(21362034 and 21462038) and the Program for Improving
Scientific Research Ability of Young Teachers of Northwest
Normal University (NWNU-LKQN-17-3) for financial support.
References
[1] a) R. Suau, F. Nájera, R. Rico, Tetrahedron 1999, 55,
4019‒4028; (b) R. Suau, F. Nájera, R. Rico,
Tetrahedron Lett. 1996, 37, 3575‒3578; c) P. C. Bansal,
I. H. Pitman, J. N. S. Tam, M. Mertes, J. J. Kaminski, J.
Pharm. Sci. 1981, 70, 850‒854.
[6] For a review, see: K. Natte, H. Neumann, M. Beller, R.
V. Jagadeesh, Angew. Chem. 2017, 129, 6482‒6492;
Angew. Chem. Int. Ed. 2017, 56, 6384‒6394.
[7] a) F. Minisci, O. Porta, F. Recupero, C. Punta, C.
Gambarotti, B. Pruna, M. Pierini, F. Fontana, Synlett
2004, 0874‒0876; b) B. Bohman, B. Berntsson, R. C.
M. Dixon, C. D. Stewart, R. A. Barrow, Org. Lett. 2014,
16, 2787‒2789; c) C. A. Huff, R. D. Cohen, K. D.
Dykstra, E. Streckfuss, D. A. DiRocco, S. W. Krska, J.
Org. Chem. 2016, 81, 6980‒6987; d) L. Zhou, N.
Okugawa, H. Togo, Eur. J. Org. Chem. 2017, 6239‒
6245.
[2] For selected examples, see: a) S. Biswas, B. Dutta, A.
Mannodi-Kanakkithodi, R. Clarke, W. Song, R.
Ramprasad, S. L. Suib, Chem. Commun. 2017, 53,
11751‒11754; b) X.-F. Wu, M. Sharif, J.-B. Feng, H.
Neumann, A. Pews-Davtyan, P. Langer, M. Beller,
Green Chem. 2013, 15, 1956‒1961; c) S. Iida, H. Togo,
Tetrahedron 2007, 63, 8274‒8281.
[3] For a review, see: a) B. Sam, B. Breit, M. J. Krische,
Angew. Chem. 2015, 127, 3317‒3325; Angew. Chem.
Int. Ed. 2015, 54, 3267‒3274; For examples, see: b) Y.
Wu, B. Zhou, ACS Catal. 2017, 7, 2213‒2217; c) G.-F.
Zhang, Y. Li, X.-Q. Xie, C.-R. Ding, Org. Lett. 2017,
19, 1216‒1219; d) V. J. Garza, M. J. Krische, J. Am.
[8] a) B. Rossi, N. Pastori, A. Clerici, C. Punta,
Tetrahedron 2012, 68, 10151‒10156; b) A. Clerici, A.
Ghilardi, N. Pastori, C. Punta, O. Porta, Org. Lett. 2008,
10, 5063‒5066.
Chem. Soc. 2016, 138, 3655‒3658; e) X. Gao, J. Han, L. [9] J. Moran, A. Preetz, R. A. Mesch, M. J. Krische, Nat.
Wang, Org. Chem. Front. 2016, 3, 656‒660; f) K. J.
Hale, Z. Xiong, L. Wang, S. Manaviazar, R. Mackle,
Org. Lett. 2015, 17, 198‒201; g) T. Yamamoto, A.
Zhumagazin, T. Furusawa, R. Tanaka, T. Yamakawa,
Y. Oe, T. Ohta, Adv. Synth. Catal. 2014, 356, 3525‒
3529; h) H.-J. Li, Y.-Y. Wu, Q.-X. Wu, R. Wang, C.-Y.
Dai, Z.-L. Shen, C.-L. Xie, Y.-C. Wu, Org. Biomol.
Chem. 2014, 12, 3100‒3107; i) X.-L. Liu, Y.-H. Liao,
Z.-J. Wu, L.-F. Cun, X.-M. Zhang, W.-C. Yuan, J. Org.
Chem. 2010, 75, 4872‒4875; j) R. G. Soengas, A. M.
Estévez, Synlett 2010, 2625‒2627; k) T. Smejkal, H.
Han, B. Breit, M. J. Krische, J. Am. Chem. Soc. 2009,
131, 10366‒10367; l) K. Bica, P. Gaertner, Eur. J. Org.
Chem. 2008, 3453‒3456; m) C. Ogawa, S. Kobayashi,
Chem. Lett. 2007, 36, 56‒57; n) S. Shirakawa, S.
Shimizu, Synlett 2007, 3160‒3164; o) F. Rezgui, M. M.
El Gaied, Tetrahedron Lett. 1998, 39, 5965‒5966; p) P.
A. Grieco, K. Hiroi, J. Chem. Soc., Chem. Commun.
1972, 1317‒1318.
Chem. 2011, 3, 287‒290.
[10] K. D. Nguyen, D. Herkommer, M. J. Krische, J. Am.
Chem. Soc. 2016, 138, 14210‒14213.
[11] For reviews, see: a) F. Huang, Z. Liu, Z. Yu, Angew.
Chem. 2016, 128, 872‒885; Angew. Chem. Int. Ed.
2016, 55, 862‒875; b) Y. Obora, Top. Curr. Chem.
2016, 374, 11; For examples, see: c) L. K. M. Chan, D.
L. Poole, D. Shen, M. P. Healy, T. J. Donohoe, Angew.
Chem. 2014, 126, 780‒784; Angew. Chem. Int. Ed.
2014, 53, 761‒765; d) S. Ogawa, Y. Obora, Chem.
Commun. 2014, 50, 2491‒2493; e) X. Quan, S.
Kerdphon, P. G. Andersson, Chem. Eur. J. 2015, 21,
3576‒3579; f) D. Shen, D. L. Poole, C. C. Shotton, A.
F. Kornahrens, M. P. Healy, T. J. Donohoe, Angew.
Chem. 2015, 127, 1662‒1665; Angew. Chem. Int. Ed.
2015, 54, 1642‒1645; g) T. T. Dang, A. M. Seayad,
Adv. Synth. Catal. 2016, 358, 3373‒3380; h) L. Jiang, F.
Guo, Z. Shi, Y. Li, Z. Hou, ChemCatChem 2017, 9,
3827‒3832; i) Z. Liu, Z. Yang, X. Yu, H. Zhang, B. Yu,
Y. Zhao, Z. Liu, Org. Lett. 2017, 19, 5228‒5231.
[4] a) S. Kobayashi, M. Kokubo, K. Kawasumi, T. Nagano,
Chem. Asian J. 2010, 5, 490‒492; b) A. Chen, J. Xu, W.
Chiang, C. L. L. Chai, Tetrahedron 2010, 66, 1489‒
1495; c) M. Pasternak, J. Paradowska, M. Rogozińska,
[12] C. Zhu, Y. Zhang, H. Zhao, S. Huang, M. Zhang, W.
Su, Adv. Synth. Catal. 2015, 357, 331‒338.
5
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10.1002/adsc.201800467
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[13] For selected reviews, see: a) J. M. R. Narayanam, C.
R. J. Stephenson, Chem. Soc. Rev. 2011, 40, 102‒113;
b) J. Xuan, W.-J. Xiao, Angew. Chem. 2012, 124,
6934‒6944; Angew. Chem. Int. Ed. 2012, 51, 6828‒
6838; c) C. K. Prier, D. A. Rankic, D. W. C.
MacMillan, Chem. Rev. 2013, 113, 5322‒5363; d) D.
M. Schultz, T. P. Yoon, Science 2014, 343, 1239176; e)
C. Stephenson, T. Yoon, Acc. Chem. Res. 2016, 49,
2059‒2060; f) J.-P. Goddard, C. Ollivier, L.
Fensterbank, Acc. Chem. Res. 2016, 49, 1924‒1936.
[17] J.-G. Sun, H. Yang, P. Li, B. Zhang, Org. Lett. 2016,
18, 5114‒5117.
[18] A. G. Leach, K. N. Houk, C. S. Foote, J. Org. Chem.
2008, 73, 8511–8519.
[19] a) M. M. Curzu, G. A. Pinna, Synthesis 1984, 339‒
342; b) G. Bartoli, M. C. Bellucci, M. Petrini, E.
Marcantoni, L. Sambri, E. Torregiani, Org. Lett. 2000,
2, 1791‒1793.
[14] For reviews, see: a) C. Bian, A. K. Singh, L. Niu, H.
Yi, A. Lei, Asian J. Org. Chem. 2017, 6, 386‒396; b)
Y.-F. Liang, N. Jiao, Acc. Chem. Res. 2017, 50, 1640‒
1653; c) D. C. Fabry, M. Rueping, Acc. Chem. Res.
2016, 49, 1969‒1979.
[15] J. Yang, D. Xie, H. Zhou, S. Chen, C. Huo, Z. Li, Org.
Chem. Front. 2018, DOI: 10.1039/c8qo00056e.
[16] X.-F. Wang, S.-S. Yu, C. Wang, D. Xue, J. Xiao, Org.
Biomol. Chem. 2016, 14, 7028‒7037.
6
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10.1002/adsc.201800467
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