One-pot synthesis of sulfones via Ni(II)-catalyzed sulfonylation of boronic acids, Na2S2O5 and benzylic ammonium salts

Article abstract of DOI:10.1016/j.mcat.2021.111500

A one-pot nickel-catalyzed synthesis of (hetero)aryl alkyl sulfones from readily available boronic acids, sodium metabisulfite and benzylic ammonium salts as electrophiles is described. This general and efficient synthetic process is of broad scope, occurs in two steps, and delivers structural diverse sulfones, and the intermediate sulfinate is isolated. The transformation exhibits application of benzylic ammonium salts as novel electrophiles for direct insertion of SO₂ as a novel area to be investigated.

Full text of DOI:10.1016/j.mcat.2021.111500

Molecular Catalysis 505 (2021) 111500
Contents lists available at ScienceDirect
Molecular Catalysis
journal homepage: www.journals.elsevier.com/molecular-catalysis
One-pot synthesis of sulfones via Ni(II)-catalyzed sulfonylation of boronic
acids, Na2S2O5 and benzylic ammonium salts
,
Haibo Zhua b,*, Yishuai Liub, Yingying Zhangb, Liu Yangb, Jia Mengb, Qian Lib, Bozhen Gongb,
,
,
Zongbo Xieb *, Zhang-Gao Leb *
a Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices, East China University of Technology, Nanchang, 330013, China
b Jiangxi Province Key Laboratory of Synthetic Chemistry, School of Chemistry, Biology and Material Science, East China University of Technology, 330013, Nanchang,
China
A R T I C L E I N F O
A B S T R A C T
Keywords:
A one-pot nickel-catalyzed synthesis of (hetero)aryl alkyl sulfones from readily available boronic acids, sodium
metabisulfite and benzylic ammonium salts as electrophiles is described. This general and efficient synthetic
process is of broad scope, occurs in two steps, and delivers structural diverse sulfones, and the intermediate
sulfinate is isolated. The transformation exhibits application of benzylic ammonium salts as novel electrophiles
for direct insertion of SO2 as a novel area to be investigated.
Sulfones
C-N cleavage
C-S formation
Nickel catalysis
Boronic acids
Introduction
4-diazabicyclo[2.2.2]octane-sulfur dioxide [DABSO: DABCObis(sulfur
dioxide)] [24–31], K2S2O5 and Na2S2O5 [32–34]. In our previous work,
The sulfone functional group is widely present in a unique class of
highly active biological small molecules, such as pharmaceutical,
organic materials and dyes [1–4]. Great efforts have been devoted to
N-heterocyclic carbene metal-catalyzed sulfonylations for the synthesis
of sulfones from boronic acids with sulfur dioxide surrogates and various
electrophiles have been successfully achieved, such as alkyl halides and
diaryliodonium salts [35–37].
–
develop novel and effective methods to construct C S bonds [5,6],
especially in the synthesis of sulfones in the past few decades [7–11].
The electrophilic aromatic substitution of arenes [12,13], and the
oxidation of the corresponding sulfides are conventional approaches to
synthesize these valuable functional sulfones. However, the preparation
of sulfonyl chlorides requires harsh acidic reaction conditions with
limited functional group tolerance. The unpleasant odor and limited
commercial resource restricted the application of sulfides in synthesis of
sulfones. In addition, the couplings reaction of sulfinates and arylbor-
onic acids had a tremdous impact of the synthesis of sulfones [14–19],
however, low yields were afforded when electron-deficient or heteroaryl
boronic acids were used.
Recently, transition-metal-catalyzed sulfonylations of boronic acids,
aryl halides or aryl triethoxysilanes with sulfur dioxide surrogates rep-
resented significant advances, as these versatile intermediates could be
readily transformed to a variety of valuable functional compounds
(Scheme 1a) [27,38–42]. Our groups have developed an efficient
one-pot bimetal catalytic system that delivers diverse sulfonamides from
boronic acids, DABSO and electrophilic O-benzoyl hydroxylamines
under mild reaction conditions (Scheme 1b) [26,43]. Although advances
were achieved, these approaches suffer from harsh conditions, need for
external highly toxic reaction solvent, or limited compatibilities. Due to
low cost and alternative, complementary reactivity [44–48],
nickel-catalyzed reactions have been getting more popular and impor-
tant for the past few years, especially in a variety of transformations via
single-electron transfer processes [49]. Willis and co-works developed a
redox-neutral nickel-catalyzed sulfination of aryl and heteroaryl boronic
acids, using the combination of commercially available, airstable
NiBr2⋅(glyme), phenanthroline as ligand, and DABSO (Scheme 1a) [30].
As a sustainable and inexpensive base-metal catalyst, nickel catalysis
With the development of organic synthesis, gaseous sulfur dioxide
can be effectively used to synthesize various sulfonyl-derived com-
pounds through the pericyclic reactions [20–22]. However, toxic and
harmful sulfur dioxide may poison the catalytic species, limiting the
application of gaseous SO2 in transition-metal-catalyzed insertion re-
actions [23]. Rapid progress has been witnessed with the insertion of
sulfur dioxide by using the sulfur dioxide surrogate, such as 1,
* Corresponding authors at: Jiangxi Province Key Laboratory of Synthetic Chemistry, School of Chemistry, Biology and Material Science, East China University of
Technology, 330013, Nanchang, China.
E-mail addresses: hbzhu@ecut.edu.cn (H. Zhu), zbxie@ecit.edu.cn (Z. Xie), zhgle@ecit.edu.cn (Z.-G. Le).
https://doi.org/10.1016/j.mcat.2021.111500
Received 30 October 2020; Received in revised form 4 February 2021; Accepted 21 February 2021
Available online 4 March 2021
2468-8231/© 2021 Elsevier B.V. All rights reserved.

H. Zhu et al.
Molecular Catalysis 505 (2021) 111500
Scheme 1. Transition-metal-catalyzed sulfonylations.
Table 1
Table 2
Optimization of reaction conditionsa.
Reaction of benzylic ammonium iodides (2a) with various arylboronic acids
(1)a.
Entry
catalyst
base
yield (%)b
1
NiBr2 (glyme)
NiCl2 (glyme)
NiCl2
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
Li2CO3
Na3PO4
Cs2CO3
Na2CO3
tBuONa
tBuOK
Li2CO3
55
20
56
trace
70
NR
72
45
32
58
19
26
80
2
3
4
Ni(acac)2
Ni(OTf)2
–
5
6
7
Ni(OTf)2
Ni(OTf)2
Ni(OTf)2
Ni(OTf)2
Ni(OTf)2
Ni(OTf)2
Ni(OTf)2
8
9
10
11
12
13[c]
aReaction conditions: 1 (0.2 mmol, 1.0 equiv.), Ni(OTf)2 (20 mol%), tmphen (30
mol%), Li2CO3 (2.0 equiv), Na2S2O5 (0.7 equiv), in 2 mL DMF at 120 ◦C under an
atmosphere of N2 for 16 h, then 2a (2.0 equiv), N2, 120 ◦C, 24 h.
bIsolated yield.
a
Reaction conditions: 1a (0.2 mmol, 1.0 equiv), catalyst (20 mol%), tmphen
(30 mol%), base (2.0 equiv), Na2S2O5 (1.0 equiv), in 2 mL DMF at 120 ◦C under
an atmosphere of N2 for 16 h, then 2a (2.0 equiv), N2, 120 ◦C, 24 h.
b
impressive catalytic activities in cross-couplings, to our delight, this
reaction takes place when using commercially available and air-stable
NiBr2⋅(glyme), 3,4,7,8-tetramethyl-1,10-phenanthroline (tmphen) as
ligand, product 3a could be isolated in 55 % yield (Table 1, entry 1). The
reaction under Ni(OTf)2 as a catalyst afforded a relatively superior yield
(Table 1, entry 5) compared to other Ni(II) catalysts (Table 1, entries
2–5). It is also worth noting that reaction in the absence of catalysts did
not occur (Table 1, entry 6). Further evaluation of nitrogen ligands
revealed that tmphen was better to promote the reaction (for more in-
formation see the Supplementary data, Table S2). In the cases of other
organic or inorganic bases, including Li2CO3, Na3PO4, Cs2CO3, Na2CO3,
tBuONa or tBuOK, but carbonates showed good results with Li2CO3
being superior to others, and product 3a was formed in 72 % yield
(Table 1, entry 7). Using other bases resulted in diminished yields
(Table 1, entries 8–12). In order to further investigate the effects of this
method, the reaction temperature, time and molar ratio were also
considered (for more information see the Supplementary data,
Table S3). To our delight, the yield was dramatically improved to 80 %
when 0.7 equiv of Na2S2O5 was used (Table 1, entry 13). The nature of
the counterion had negative influence on the yield, and variable yields
were obtained when different benzylic ammonium salts were uesd (for
more information see the Supplementary data, Table S4). Finally, a yield
of 80 % was provided when using 20 mol% of Ni(OTf)2, 2.0 equiv of
Li2CO3, 30 mol% of tmphen, 1.0 equiv of phenylboronic acid (1a) and
0.7 equiv of Na2S2O5 in 2 mL DMF at 120 ◦C under an atmosphere of N2
for 16 h in the first step, then, adding 2.0 equiv of benzylic ammonium
Isolated yield.
c
Na2S2O5 (0.7 equiv).
can provide new reactivity in sulfination chemistry and solve the limi-
tations of current catalytic methods.
Due to the high reactivity and stability, safe to handle, and easy to
prepare, the quaternary ammonium salts have represented types of
neotype electrophilic reagents [50–53], especially in the formation of
–
–
C
C and C S bonds catalyzed by transition-metal with various nucle-
ophilic reagents [54–60]. In particular, recent remarkable achievements
have demonstrated the practical synthetic reactions via
transition-metal-free approaches to form valuable compounds,
including sulfones using the quaternary ammonium salts as novel elec-
trophiles [61–64]. To avoid the direct coupling of boronic acids and
quaternary ammonium salts under nickel catalysis, we would like to
investigate one-pot nickel-catalyzed sulfination to synthetic various
sulfones using the electrophilic quaternary ammonium salts.
Results and discussion
Initially, we commenced our research by screening a catalytic ac-
tivity of various Ni(II) complexes for the synthesis of sulfone 3a from
phenylboronic acid (1a), Na2S2O5 and benzylic ammonium iodides (2a)
in a one-pot process. We started the optimization using K2CO3 as base in
N, N-dimethylformamide (DMF) at 120 ◦C for 40 h in one-pot procedure,
various nickel catalysts were investigated since they have exhibited
2

H. Zhu et al.
Molecular Catalysis 505 (2021) 111500
and 4e, 66 % and 88 %, respectively). Notably, when a range of ortho-
substitutes even with strong electron-withdrawing (o-trifluoromethyl)
were used on the coupling process, up to 66 % yields were afforded (4f-
4i), and similar outcome was obtained when bulky 1-naphthylbenzylic
ammonium salt 4j was used on the coupling process. The results of 4f-
4j reveal that steric hindrance could activate benzylic ammonium io-
dides in this one-pot coupling reaction. The process works well for
substrates displaying (hetero)aryl ammonium salt, and good results
were observed with the couplings of 2-furyl and 2-thienyl benzylic
ammoniums as substrates (4k and 4l, 60 % and 61 %, respectively).
Oxygen-containing heterocyclic substrates could work well in the re-
action to provide the corresponding heterocyclic products 4m in 52 %
yields.
Table 3
Reaction of phenylboronic acid (1a) with various benzylic ammonium iodides
(2)a.
a Reaction conditions: 1a (0.2 mmol, 1.0 equiv), Ni(OTf)2 (20 mol%), tmphen
(30 mol%), Li2CO3 (2.0 equiv), Na2S2O5 (0.7 equiv), in 2 mL DMF at 120 ◦C
under an atmosphere of N2 for 16 h, then 2a (2.0 equiv), N2, 120 ◦C, 24 h.
b Isolated yield.
In order to stress the practicality of this protocol, we have demon-
strated the application of this Ni(II)-catalyzed one-pot multi-component
sulfone synthesis on a gram-scale (Scheme 2). When 10.0 mmol of
phenylboronic acid (1.21 g) reacted with Na2S2O5 (7.0 mmol) and
benzylic ammonium iodides (20.0 mmol) under the optimal conditions,
the expected sulfone 3a was isolated in 63 % yield, demonstrated the
high efficiency of the newly developed sulfones protocol.
iodide (2a) for another 24 h at 120 ◦C under an atmosphere of N2.
After the optimal conditions were obtained, the scope of this one-pot
reaction of phenylboronic acid, Na2S2O5 and benzylic ammonium io-
dides in the presence of Ni(OTf)2 was then explored. A range of aryl-
boronic acids were examined, and it was found that all reactions
proceeded smoothly, resulting in the desired products in moderate to
good yields (Table 2). Good results were observed when using strong
electron donating groups containing tert-butyl group or methoxy group
(3b and 3c, 81 and 80 %, respectively). Arylboronic acids bearing
electron-donating alkyl groups at meta- and para-positions of phenyl ring
performed smoothly in the reaction condition. Due to the steric hin-
drance of o-methylphenylboronic acid and 1-naphthaleneboronic acid,
no corresponding target products were obtained in this reation condi-
tions. In the cases of substrates bearing electron-donating groups (iso-
propyl, methylthio) or electron-neutral arylboronic acid (biphenyl),
only moderate yields of products were observed (3f, 3g, 3k, 40–46 %).
Boronic acids bearing different electron-withdrawing groups were well-
tolerated, delivering good isolated yields. Moderate results were
observed when using weak electron-withdrawing groups containing p-F,
p-Cl and m-F groups (3i, 3j and 3m, 50 %, 78 % and 50 % respectively),
strong electron-withdrawing groups such as trifluoromethyl and tri-
fluoromethoxy still have considerable results (3h and 3l, 65 % and 46 %
respectively). In addition, a number of heteroaromatic boronic acids
were compatible in this catalytic system, with O-, and S-heterocyclic
substrates delivering the corresponding sulfones in aceptable yields (3n
and 3o, 39 % and 41 % respectively). Unexpectedly, only trace amounts
of products were observed when we examined thiophene boronic acids,
furan boronic acids and various of N-heterocyclic substrates.
A few control experiments were carried out to gain more insights into
the mechanism (for more information see the Supplementary data). The
yields in the presence of radical inhibitors are significantly decreased,
however, the radical coupling products were not detected when TEMPO
or 1,1- diphenylethylene was added. We probably think that more than
one mechanism is at play in this coupling reaction [60,65]. On the basis
of these results and our previous works [35–37,43,66], a possible
mechanism for the transformation is proposed in Scheme 3. Initially, the
LnNi(II) species transmetalates with the aryl boronic acid to produce the
intermediate A (LnNiX-Ar) [67–69]. Next, SO2 (generated in situ from
Na2S2O5 under heating) insertion into the Ni-C bond affords a sterically
congested sulfonyl Ni(II) complex B (LnNi(II)X-SO2-Ar) [70–72]. In the
presence of
a suitable base, along with regeneration of the
less-congested LnNi(II) catalyst to complete the catalytic cycle, the key
intermediate arylsulfinate C is produced, which further reacts with the
selected electrophilic quaternary ammonium salts to afford the corre-
sponding sulfone products. More detailed mechanistic studies of these
reactions are ongoing in our laboratory.
Conclusions
In conclusion, we have developed an efficient one-pot nickel cata-
lytic system that delivers structurally diverse sulfones from readily
available boronic acids, Na2S2O5 and benzylic ammonium salts. This
general and efficient synthetic process works well with a wide range of
benzylic ammonium salts and various functional boronic acids, and the
intermediate sulfinate was isolated. The transformation exhibits appli-
cation of Nickel catalysis for direct insertion of SO2 into aryl-benzyl
sulfone synthesis as a novel area to be investigated. At the same time,
the application of benzyl quaternary ammonium salt as a new electro-
philic reagent in sulfonylation was expanded.
Subsequently, we investigated the feasibility of the protocol toward
electrophilic benzylic ammonium iodides (Table 3). Both benzylic
ammonium iodides with electron-withdrawing and electron-donating
groups attached on the phenyl ring were compatible in this process
(4a-4i). The relative position of the methyl group on the aromatic ring of
benzyl ammonium iodide has a slight effect on the conversion efficiency,
and considerable yields were obtained with ortho-, meta-, and para-
substituents (4a-4c, 46–68 %). The benzyl ammonium iodides with
strong electron donor groups including methoxy and tert-butyl had good
compatibilities, and excellent yields were produced in synthetically (4d
CRediT authorship contribution statement
Haibo Zhu: Conceptualization, Methodology, Writing - review &
editing. Yishuai Liu: Data curation, Writing - original draft. Yingying
Scheme 2. Gram-scale synthesis of the sulfone 3a.
3

H. Zhu et al.
Molecular Catalysis 505 (2021) 111500
Scheme 3. Proposed reaction mechanism.
[17] S.L. Jain, B.S. Rana, B. Singh, A.K. Sinha, A. Bhaumik, M. Nandi, B. Sain, Green
Chem. 12 (2010) 374–377.
Zhang: Resources. Liu Yang: Investigation. Jia Meng: Validation. Qian
Li: Validation. Bozhen Gong: Validation. Zongbo Xie: Supervision.
Zhang-Gao Le: Supervision.
[18] N. Fukuda, T. Ikemoto, J. Org. Chem. 75 (2010) 4629–4631.
[19] B.M. Choudary, C.R.V. Reddy, B.V. Prakash, M.L. Kantam, B. Sreedhar, Chem.
Commun. (2003) 754–755.
[20] A. Stikute, J. Lugin¸ina, M. Turks, Tetrahedron Lett. 58 (2017) 2727–2731.
[21] A. Stikute, V. Peipin¸s, M. Turks, Tetrahedron Lett. 56 (2015) 4578–4581.
[22] P. Vogel, M. Turks, L.C. Bouchez, D. Markovic, A. Varelaalvarez, J. Sordo, Acc.
Chem. Res. 40 (2007) 931–942.
Declaration of Competing Interest
The authors declare that they have no known competing financial
interests or personal relationships that could have appeared to influence
the work reported in this paper.
[23] L.M. Wojcinski, M.T. Boyer, A. Sen, Inorganica Chim. Acta 270 (1998) 8–11.
[24] S. Ye, G. Qiu, J. Wu, Chem. Commun. 55 (2019) 1013–1019.
[25] G. Qiu, K. Zhou, J. Wu, Chem. Commun. 54 (2018) 12561–12569.
[26] H. Zhu, Y. Shen, Q. Deng, Z.-G. Le, T. Tu, Asian J. Org. Chem. 6 (2017) 1542–1545.
[27] Y. Chen, M.C. Willis, Chem. Sci. 8 (2017) 3249–3253.
[28] E.J. Emmett, B.R. Hayter, M.C. Willis, Angew. Chem. Int. Ed. 53 (2014)
10204–10208.
Acknowledgments
[29] S. Chen, Y. Li, M. Wang, X. Jiang, Green Chem. 22 (2020) 322–326.
[30] P.K.T. Lo, Y. Chen, M.C. Willis, ACS Catal. 9 (2019) 10668–10673.
[31] K. Gulbe, Mr. Turks, J. Org. Chem. 85 (2020) 5660–5669.
[32] M. Wang, J. Zhao, X. Jiang, ChemSusChem 12 (2019) 3064–3068.
[33] M. Wang, Q. Fan, X. Jiang, Green Chem. 20 (2018) 5469–5473.
[34] S. Ye, J. Wu, Chem. Commun. 48 (2012) 10037–10039.
[35] H. Zhu, Y. Shen, Q. Deng, J. Chen, T. Tu, ACS Catal. 7 (2017) 4655–4659.
[36] H. Zhu, Y. Shen, Q. Deng, J. Chen, T. Tu, Chem. Commun. 53 (2017)
12473–12476.
Financial support from the National Natural Science Foundation of
China (21801040), the Natural Science Foundation of Jiangxi Province
(20192BAB213006), the Science and Technology Projects of Jiangxi
(20181BBH80007), the Opening Project of Jiangxi Province Key Labo-
ratory of Polymer Micro/Nano Manufacturing and Devices
(PMND202001), East China University of Technology Research Foun-
dation for Advanced Talents (DHBK2017168) and School of Chemistry,
Biology and Material Science at East China University of Technology is
gratefully acknowledged.
[37] H. Zhu, Y. Shen, D. Wen, Z.-G. Le, T. Tu, Org. Lett. 21 (2019) 974–979.
[38] Y. Chen, P.R.D. Murray, A.T. Davies, M.C. Willis, J. Am. Chem. Soc. 140 (2018)
8781–8787.
[39] D. Zheng, M. Chen, L. Yao, J. Wu, Org. Chem. Front. 3 (2016) 985–988.
[40] D. Zheng, R. Mao, Z. Li, J. Wu, Org. Chem. Front. 3 (2016) 359–363.
[41] R. Mao, D. Zheng, H. Xia, J. Wu, Org. Chem. Front. 3 (2016) 693–696.
[42] A. Shavnya, K.D. Hesp, V. Mascitti, A.C. Smith, Angew. Chem. Int. Ed. 54 (2015)
13571–13575.
Appendix A. Supplementary data
Supplementary material related to this article can be found, in the
online version, at doi:https://doi.org/10.1016/j.mcat.2021.111500.
[43] H. Zhu, Y. Shen, Q. Deng, C. Huang, T. Tu, Chem. Asian J. 12 (2017) 706–712.
¨
[44] M. Borjesson, T. Moragas, D. Gallego, R. Martin, ACS Catal. 6 (2016) 6739–6749.
[45] M. Tobisu, N. Chatani, Acc. Chem. Res. 48 (2015) 1717–1726.
[46] V.P. Ananikov, ACS Catal. 5 (2015) 1964–1971.
References
[47] S.Z. Tasker, E.A. Standley, T.F. Jamison, Nature 509 (2014) 299–309.
[48] B.M. Rosen, K.W. Quasdorf, D.A. Wilson, N. Zhang, A.-M. Resmerita, N.K. Garg,
V. Percec, Chem. Rev. 111 (2011) 1346–1416.
[1] C. Shen, P. Zhang, Q. Sun, S. Bai, T.S.A. Hor, X. Liu, Chem. Soc. Rev. 44 (2015)
291–314.
[49] H. Yue, C. Zhu, M. Rueping, Angew. Chem. Int. Ed. 57 (2018) 1371–1375.
[50] L.G. Xie, Z.X. Wang, Angew. Chem. Int. Ed. 50 (2011) 4901–4904.
[51] S.B. Blakey, D.W.C. MacMillan, J. Am. Chem. Soc. 125 (2003) 6046–6047.
[52] E. Wenkert, A.-L. Han, C.-J. Jenny, J. Chem. Soc. Chem. Commun. (1998) 975–976.
[53] F. Zhu, J.L. Tao, Z.X. Wang, Org. Lett. 17 (2015) 4926–4929.
[54] W. Jiang, N. Li, L. Zhou, Q. Zeng, ACS Catal. 8 (2018) 9899–9906.
[55] F. Lu, Z. Chen, Z. Li, X. Wang, X. Peng, C. Li, R. Li, H. Pei, H. Wang, M. Gao, Asian
J. Org. Chem. 7 (2018) 141–144.
[2] Q. Lu, J. Zhang, F. Wei, Y. Qi, H. Wang, Z. Liu, A. Lei, Angew. Chem. Int. Ed. 52
(2013) 7156–7159.
[3] C. Zhang, C. Tang, N. Jiao, Chem. Soc. Rev. 41 (2012) 3464–3486.
[4] D.A. Bachovchin, A.M. Zuhl, A.E. Speers, M.R. Wolfe, E. Weerapana, S.J. Brown,
H. Rosen, B.F. Cravatt, J. Med. Chem. 54 (2011) 5229–5236.
[5] N.S. Simpkins, Sulphones in Organic Synthesis, Elsevier, 2013.
[6] S. Patai, Z. Rappoport, C. Stirling, The Chemistry of Sulphones and Sulphoxides,
Vol. 2, Wiley, 1988.
[56] T. Wang, S. Yang, S. Xu, C. Han, G. Guo, J. Zhao, RSC Adv. 7 (2017) 15805–15808.
[57] X. Liu, H. Zhu, Y. Shen, J. Jiang, T. Tu, Chin. Chem. Lett. 28 (2017) 350–353.
[58] T. Moragas, M. Gaydou, R. Martin, Angew. Chem. Int. Ed. 55 (2016) 5053–5057.
[59] C.H. Basch, K.M. Cobb, M.P. Watson, Org. Lett. 18 (2016) 136–139.
[60] P. Maity, D.M. Shacklady-McAtee, G.P. Yap, E.R. Sirianni, M.P. Watson, J. Am.
Chem. Soc. 135 (2013) 280–285.
[7] Y. Meng, M. Wang, X. Jiang, Angew. Chem. Int. Ed. 59 (2020) 1346–1353.
[8] X. Gong, M. Wang, S. Ye, J. Wu, Org. Lett. 21 (2019) 1156–1160.
[9] X. Gong, J. Chen, L. Lai, J. Cheng, J. Sun, J. Wu, Chem. Commun. 54 (2018)
11172–11175.
[10] F. Xiao, S. Chen, Y. Chen, H. Huang, G.-J. Deng, Chem. Commun. 46 (2015)
652–654.
[61] Y. Liu, H. Zhu, L. Yang, Z. Xie, G. Jiang, Z. Le, T. Tu, Asian J. Org. Chem. 9 (2020)
247–250.
[11] J. Aziz, S. Messaoudi, M. Alami, A. Hamze, Org. Biomol. Chem. 12 (2014)
9743–9759.
[62] D.-Y. Wang, X. Wen, C.-D. Xiong, J.-N. Zhao, C.-Y. Ding, Q. Meng, H. Zhou,
C. Wang, M. Uchiyama, X.-J. Lu, A. Zhang, iScience 15 (2019) 307–315.
[63] J.-N. Zhao, M. Kayumov, D.-Y. Wang, A. Zhang, Org. Lett. 21 (2019) 7303–7306.
[64] D.-Y. Wang, Z.-K. Yang, C. Wang, A. Zhang, M. Uchiyama, Angew. Chem. Int. Ed.
57 (2018) 3641–3645.
[12] M. Ueda, K. Uchiyama, T. Kano, Synthesis 4 (1984) 323–325.
[13] B.M. Graybill, J. Org. Chem. 32 (1967) 2931–2933.
[14] A. Kar, I.A. Sayyed, W.F. Lo, H.M. Kaiser, M. Beller, M.K. Tse, Org. Lett. 9 (2007)
3405–3408.
[15] W. Zhu, D. Ma, J. Org. Chem. 70 (2005) 2696–2700.
[16] B.P. Bandgar, S.V. Bettigeri, J. Phopase, Org. Lett. 6 (2004) 2105–2108.
4

H. Zhu et al.
Molecular Catalysis 505 (2021) 111500
[65] M. Miao, L.-L. Liao, G.-M. Cao, W.-J. Zhou, D.-G. Yu, Sci. China Chem. 62 (2019)
1519–1524.
[69] S. Akkarasamiyo, J. Margalef, J.S.M. Samec, Org. Lett. 21 (2019) 4782–4787.
[70] Y. Yang, Q. Zhou, J. Cai, T. Xue, Y. Liu, Y. Jiang, Y. Su, L. Chung, D.A. Vicic, Chem.
Sci. 10 (2019) 5275–5282.
[66] K.M. Maloney, J.T. Kuethe, K. Linn, Org. Lett. 13 (2011) 102–105.
[67] A. Ohtsuki, K. Yanagisawa, T. Furukawa, M. Tobisu, N. Chatani, J. Org. Chem. 81
(2016) 9409–9414.
[71] R.T. Simons, G.E. Scott, A.G. Kanegusuku, J.L. Roizen, J. Org. Chem. 85 (2020)
6380–6391.
[68] Y. Li, Y. Luo, L. Peng, Y. Li, B. Zhao, W. Wang, H. Pang, Y. Deng, R. Bai, Y. Lan,
G. Yin, Nat. Commun. 11 (2020) 417.
[72] J. Liang, J. Han, J. Wu, P. Wu, J. Hu, F. Hu, F. Wu, Org. Lett. 21 (2019) 6844–6849.
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