Iron-Catalyzed Three-Component Cyanoalkylsulfonylation of 2,3-Allenoic Acids, Sulfur Dioxide, and Cycloketone Oxime Esters: Access to Cyanoalkylsulfonylated Butenolides

Article abstract of DOI:10.1002/adsc.202100463

An iron-catalyzed three-component cyanoalkylsulfonylation of 2,3-allenoic acids, K₂S₂O₅, and the ring-opening of cyclobutanone oxime esters is described. The radical tandem cyclization route allows access to diverse cyanoa

Full text of DOI:10.1002/adsc.202100463

UPDATES
DOI: 10.1002/adsc.202100463
Iron-Catalyzed Three-Component Cyanoalkylsulfonylation of 2,3-
Allenoic Acids, Sulfur Dioxide, and Cycloketone Oxime Esters:
Access to Cyanoalkylsulfonylated Butenolides
Xiangyun Zheng,a Tianshuo Zhong,a Xiao Yi,a Qitao Shen,a Chuanliu Yin,a
Lei Zhang,a Jian Zhou,a Junyu Chen,a and Chuanming Yua,*
a
College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, People’s Republic of China
E-mail: ycm@zjut.edu.cn
Manuscript received: April 14, 2021; Version of record online: ■■■, ■■■■
Supporting information for this article is available on the WWW under https://doi.org/10.1002/adsc.202100463
reactions to obtain complex furan-2(5H)-ones remains
Abstract: An iron-catalyzed three-component cya-
highly desirable.
noalkylsulfonylation of 2,3-allenoic acids, K2S2O5,
and the ring-opening of cyclobutanone oxime esters
Cyanoalkylsulfonyl groups are valuable organic
building blocks for the synthesis of bioactive
is described. The radical tandem cyclization route
molecules.[10] In addition, they can also be easily
allows access to diverse cyanoalkylsulfonylated
transformed into other useful functional groups.[11] In
butenolides in moderate to good yields under mild
recent years, various synthetic approaches have been
conditions. Moreover, the products are further
established for the introduction of cyanoalkylsulfonyl
converted, offering the corresponding derivatives.
groups. In 2008, Felton[12] reported the electrochemical
reduction of alkyl vinyl sulfones with acetonitrile to
obtain cyanoalkylsulfonyl groups. Later, Landais and
Keywords: Butenolides; Three-component; Cyanoal-
coworkers[13] demonstrated the three-component cya-
kylsulfonylation; Iron-catalyzed; Derivatization
noalkylsulfonylation of α-bromosulfone, olefin, and p-
Introduction
Furan-2(5H)-ones represent a prominent class of
structural scaffolds widely found in natural products
and biologically active compounds (Figure 1).[1] Alle-
noic acids have been intensively employed as synthons
to obtain furan-2(5H)-one derivatives, owing to their
high reactivity and easy preparation.[2] For example,
Ma and co-workers initially developed palladium-
catalyzed coupling cyclization of 2,3-allenoic acids
with allenes,[3] alkynes,[4] alkenes,[5] or aryl iodides[6] to
afford polysubstituted butenolides (Scheme 1a). After-
ward, Ma[7] and Qing[8] reported the copper-catalyzed
free radical cyclization of 2,3-allenoic acids with
Figure 1. Biologically active compounds containing furan-
2(5H)-ones.
various free radical donors to form various furan-
2(5H)-one compounds. In addition, Wu[9] and co-
workers reported the synthesis of arylsulfonylated
butenolides via a copper(II)-catalyzed three-component
reaction (Scheme 1b). Despite the successful imple- tosyl cyanide. Moreover, Chen[14] reported the copper-
mentation of these synthetic methods, the development catalyzed cross-coupling of oxime esters and sulfinates
of novel types of catalysts and multicomponent for the synthesis of cyanoalkylsulfonyl groups.
Although some examples[15] of the synthesis of
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Table 1. Optimization of reaction conditions.[a]
Entry
Catalyst
Solvent
Yield (%)[b]
1
2
3
4
5
6
7
8
Cu(OAc)2
CuOAc
FeCl2
Ni(acac)2
Cu(CH3CN)4BF4
Fe(OTf)2
Fe(OTf)3
FeCl3
Fe(OAc)2
FeCl2
FeCl2
FeCl2
FeCl2
DCE
DCE
DCE
DCE
DCE
DCE
DCE
DCE
DCE
CH3CN
THF
1,4-dioxane
DCE
DCE
DCE
DCE
DCE
DCE
18
trace
65
0
20
35
50
54
45
25
trace
8
42
10
42
60
55
75
9
10
11
12
13c
14d
15e
16f
17g
18h
Scheme 1. Synthesis of various butenolides.
FeCl2
FeCl2
FeCl2
FeCl2
cyanoalkylsulfonyl groups using cyclobutanone oxime
[17]
esters[16] and K2S2O5
as cyanoalkyl and sulfonyl
group sources,[18] respectively, have been reported,
synthesis methods of cyanoalkylsulfonylated buteno-
lides are not very common. Based on our previous
work on radical synthesis,[19] herein we report the iron-
catalyzed three-component cyanoalkylsulfonylation of
2,3-allenoic acids and the ring opening of O-acyl
oximes with the insertion of sulfur dioxide.
FeCl2
[a] Reaction conditions: 1a (0.2 mmol), 2a (0.3 mmol), catalyst
°
(10 mol%), K2S2O5 (2 equiv.), and DCE (2 mL) at 60 C for
18 h under Ar atmosphere.
[b] Isolated yield.
[c] Na2S2O5.
[d] DABSO.
[e]
°
50 C.
[f]
Results and Discussion
°
70 C.
[g] 12 h.
[h] 24 h.
First, a model reaction between 2-methyl-4-phenyl-
2,3-allenoic acid (1a), K2S2O5, and cyclobutanone O-
(4-(trifluoromethyl)benzoyl) oxime (2a) was carried
out in the presence of catalytic Cu(OAc)2 under Ar
°
atmosphere at 60 C for 18 h, and the cyanoalkylsulfo- with different allenes (Scheme 2). We mainly consid-
nylated product 3a was isolated in 18% yield (Table 1, ered 2,3-allenoic acids bearing the R1 substituent group
entry 1). Among the various screened catalysts (en- on the aromatic ring. Different substituents containing
tries 1–9), FeCl2 proved to be most suitable one, electron-donating groups such as methyl and methoxy
providing 3a in 65% yield (entry 3). However, lower groups in para position or bis-methyl substituents of
yields (0–25%) were obtained when other solvents, the aromatic ring reacted smoothly and with high
such as MeCN, tetrahydrofuran (THF), and 1,4- efficiency, delivering the cyclization products 3a–3d
dioxane were employed (entries 10–12). Next, screen- in 67–78% yields. Halogen substituents at the para,
ing of sulfur dioxide surrogates revealed that K2S2O5 ortho, or meta positions of the aromatic ring were also
was still the most efficient reagent (entries 13 and 14). well tolerated, affording the corresponding compounds
In addition, changing the reaction temperature and 3e–3i in 22–59% yields. However, substrate 1, bearing
reducing the reaction time resulted in lower yields methyl and methoxy groups at the ortho position,
(entries 15–17). Interestingly, a 75% yield of 3a was delivered the desired products 3j and 3k in relatively
achieved upon extending the reaction time to 24 h low yields compared to electron-donating groups at the
(entry 18). Therefore, the optimal conditions were para position, presumably due to steric hindrance
determined as follows: 1a (0.2 mmol), 2a (0.3 mmol), effects. In addition, when the aromatic ring was
K2S2O5 (0.4 mmol), FeCl2 (10 mol.%), and DCE replaced by a naphthalene unit, an unexpected cycliza-
°
(2 mL), under Ar atmosphere at 60 C for 24 h.
tion product (3l) was formed in 70% yield. Interest-
Based on the above optimized conditions, we next ingly, this reaction type could also be utilized for the
explored the substrate cyanoalkylsulfonylation reaction substrate with n-propyl as R3 substituent (3m).
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Scheme 3. Reaction of 2-methyl-4-phenyl-2,3-allenoic acid 1a
a
with cyclobutanone oxime esters derivatives 2.
Reaction
conditions A: 1a (0.2 mmol), 2 (0.3 mmol), FeCl2 (10 mol%),
°
K2S2O5 (2 equiv.), and DCE (2 mL) at 60 C for 24 h under Ar
atmosphere. b Isolated yields.
Scheme 2. Reaction of 2,3-Allenoic acids 1 with cyclobutanone
a
O-(4-(trifluoromethyl)benzoyl) oxime 2a. Reaction conditions
A: 1 (0.2 mmol), 2a (0.3 mmol), FeCl2 (10 mol%), K2S2O5
°
(2 equiv.), and DCE (2 mL) at 60 C for 24 h under Ar
atmosphere. b Isolated yields.
Similarly, both Ph and Me groups were effective
substituents at the R2 position (3n and 3o). The crystal
structure of compound 3c was confirmed by X-ray
crystallographic analysis (see Supporting Information
for details).[20]
Scheme 4. Transformation of butenolides.
To further extend the versatility of this radical
cascade cyclization reaction, we evaluated a series of 3a can easily be transformed to provide the N-tert-
3-substituted
cyclobutanone
oxime
esters
2
butyl-substituted amide 5b through a Ritter reaction.
(Scheme 3). As expected, various functional groups
A series of control experiments were conducted to
including aryl, benzyl, ester, and benzyloxy moieties determine the detailed reaction mechanism (Scheme 5).
were compatible, producing the desired products 4a– Although product 3a was not obtained in the presence
4k (25–60%). Importantly, 3-disubstituted compounds of the 1,1-diphenylethene (DPE), TEMPO, and BHT
also reacted smoothly to afford the 4l and 4m radical scavengers, compound 6 was detected by GC-
compounds in 51% and 19% yields. However, other MS. Furthermore, compounds 7 and 8 could be
cycloketone oximes 2n and 2o failed to form the isolated in 34% and 13% yield respectively when DPE
desired product.
was added to a sulfonylation reaction mixture. These
We synthesized derivatives of sulfonylated product experimental results indicate the occurrence of a
3a, to demonstrate its synthetic value (Scheme 4). For radical process in this reaction. On the other hand, no
instance, 3a could undergo lactone ring opening and reaction occurred when the 2,3-allenoate 9 replaced
butanolysis to yield product 5a in the presence of n- allenoic acid, proving the crucial role of allenoic acid
butanol and ZnCl2. Furthermore, the cyano group of as a directing group for the cyanoalkylsulfonylation
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to form the intermediate D. Under Fe(III) catalysis, the
allylic cation E is generated from the oxidation of
radical species D, while Fe(II) is regenerated. Finally,
the intramolecular nucleophilic attack of intermediate
D yields the cyclization product 3a.
Conclusion
In conclusion, we have successfully developed an iron-
catalyzed cyanoalkylsulfonylation of 2,3-allenoic
acids, leading to a variety of cyanoalkylsulfonylated
butenolides under mild conditions. The use of K2S2O5
as sulfur dioxide surrogate renders this approach both
safer and more environmentally friendly than other
synthetic methods. Moreover, further transformations
of the cyanoalkylsulfonylated butenolides provided the
corresponding derivatives. Most of these compounds
were previously unknown; additional experiments
evaluating the further applicability of this protocol are
currently being performed in our laboratory.
Scheme 5. Control experiments.
Experimental Section
reaction. In addition, the reaction of 10 and 2a did not General Procedure for the Synthesis of Cyanoalky-
yield the desired product 3a under standard conditions, sulfonylated Butenolides
suggesting that 2,3-allenoic acids may not first undergo
intramolecular cyclization to form 10, and then reacted
with sulfonyl radical.
A mixture of 2,3-allenoic acids 1 (1 equiv., 0.2 mmol), O-(4-
(trifluoromethyl)benzoyl) oximes 2 (1.5 equiv., 0.3 mmol), and
K2S2O5 (2 equiv., 0.4 mmol), FeCl2 (0.1 equiv., 0.02 mmol) and
Based on the control experiments discussed above
°
DCE (2 mL) was heated at 60 C for 24 h in a sealed tube
as well as previous studies,[7,8,15a–c] we propose a
(10 mL). After the reaction finished, the reaction mixture was
possible free radical pathway for the present cascade
cyclization. (Scheme 6). Initially, SET reduction of the
cycloketone oxime ester 2a catalyzed by Fe(II) leads
to the cleavage of NÀ O bonds, forming the iminyl
radical intermediate A. Subsequently, the CÀ C bond
cleavage of intermediate A yields the alkyl radical
species B. Next, sulfur dioxide, originated from
K2S2O5, attacks the intermediate B to give sulfonyl
radical C, followed by addition to 2,3-allenoic acid 1a
cooled to room temperature and diluted with dichloromethane
(5×3 mL), and the organic layers were combined, washed with
sat. aq. Na2CO3 (10 mL), dried (Na2SO4), and concentrated in
vacuo. The residue was purified by column chromatography to
afford the desired product.
Acknowledgements
We are thankful to the National Natural Science Foundation of
China (NSFC) (Grant No. 21676252 and 21506191) for their
financial support.
References
[1] a) E. Adelin, M. T. Martin, M. F. Bricot, S. Cortial, P.
Retailleau, J. Ouazzani, Phytochemistry. 2012, 84, 135–
140; b) H. Xiao, K. L. Parkin, Phytochemistry. 2007, 68,
1059–1067; c) W. S. Hamama, M. E. Ibrahim, E. A.
Ghaith, H. H. Zoorob, Synth. Commun. 2017, 47, 566–
580; d) E. Ehrich, A. Dallob, I. Delepeleire, A.
Vanhecken, D. Riendeau, W. Yuan, A. Porras, J.
Wittreich, J. Seibold, P. Deschepper, Clin. Pharmacol.
Ther. 1999, 65, 336–347.
[2] a) S. Ma, Chem. Rev. 2005, 105, 2829–2872; b) M.
Brasholz, H. U. Reissig, R. Zimmer, Acc. Chem. Res.
2009, 42, 45–56; c) L. Liu, R. M. Ward, J. M. Scho-
maker, Chem. Rev. 2019, 119, 12422–12490.
Scheme 6. Proposed reaction mechanism.
Adv. Synth. Catal. 2021, 363, 1–7
4
© 2021 Wiley-VCH GmbH
��
These are not the final page numbers!

UPDATES
asc.wiley-vch.de
[3] a) S. Ma, Z. Gu, J. Am. Chem. Soc. 2005, 127, 6182– [13] H. Hassan, V. Pirenne, M. Wissing, C. Khiar, A. Hussain,
6183; b) Z. Gu, X. Wang, W. Shu, S. Ma, J. Am. Chem.
Soc. 2007, 129, 10948–10956.
F. Robert, Y. Landais, Chem. Eur. J. 2017, 23, 4651–
4658.
[4] a) Z. Gu, S. Ma, Angew. Chem. Int. Ed. 2006, 45, 6002– [14] X. S. Zhou, Y. Cheng, J. Chen, X. Y. Yu, W. J. Xiao,
6005; Angew. Chem. 2006, 118, 6148–6151; b) S. Ma, Z. J. R. Chen, ChemCatChem. 2019, 11, 5300–5305.
Gu, Y. Deng, Chem. Commun. 2006, 94, 94–96; c) G. [15] a) J. Zhang, X. Li, W. Xie, S. Ye, J. Wu, Org. Lett. 2019,
Chen, R. Zeng, Z. Gu, C. Fu, S. Ma, Org. Lett. 2008, 10,
4235–4238.
[5] S. Ma, Z. Yu, J. Org. Chem. 2003, 68, 6149–6152.
[6] S. Ma, D. Duan, Y. Wang, J. Comb. Chem. 2002, 4, 239–
247.
[7] Q. Yu, S. Ma, Chem. Eur. J. 2013, 19, 13304–13308.
[8] a) Y. X. Xin, S. Pan, Y. Huang, X. H. Xu, F. L. Qing, J.
Org. Chem. 2018, 83, 6101–6109; b) S. Pan, Y. Huang,
X. H. Xu, F. L. Qing, Org. Lett. 2017, 19, 4624–4627.
[9] K. Zhou, J. Zhang, G. Qiu, J. Wu, Org. Lett. 2019, 21,
275–278.
21, 4950–4954; b) Y. Liu, Q. L. Wang, Z. Chen, H. Li,
B. Q. Xiong, P. L. Zhang, K. W. Tang, Chem. Commun.
2020, 56, 3011–3014; c) J. Zhang, M. Yang, J. B. Liu,
F. S. He, J. Wu, Chem. Commun. 2020, 56, 3225–3228;
d) J. Zhang, X. Wang, Y. Kuang, J. Wu, iScience. 2020,
23, 101872; e) Z. Chen, Q. Zhou, Q. L. Wang, P. Chen,
B. Q. Xiong, Y. Liang, K. W. Tang, Y. Liu, Adv. Synth.
Catal. 2020, 362, 3004–3010.
[16] a) D. Yang, H. Huang, M. H. Li, X. J. Si, H. Zhang, J. L.
Niu, M. P. Song, Org. Lett. 2020, 22, 4333–4338; b) Y.
Deng, C. Zhao, Y. Zhou, H. Wang, X. Li, G. J. Cheng, J.
Fu, Org. Lett. 2020, 22, 3524–3530; c) M.-M. Zhang, S.-
H. Li, J.-L. Tu, Q.-Q. Min, F. Liu, Org. Chem. Front.
2020, 7, 622–627; d) J. Li, S. Y. Wang, S. J. Ji, J. Org.
Chem. 2019, 84, 16147–16156; e) J. X. Yu, F. Teng,
J. N. Xiang, W. Deng, J. H. Li, Org. Lett. 2019, 21,
9434–9437; f) W. L. Xing, R. Shang, G. Z. Wang, Y. Fu,
Chem. Commun. 2019, 55, 14291–14294; g) B. Zhao, M.
Wang, Z. Shi, J. Org. Chem. 2019, 84, 10145–10159;
h) J. Lou, Y. He, Y. Li, Z. Yu, Adv. Synth. Catal. 2019,
361, 3787–3799; i) W. Zhang, Y. L. Pan, C. Yang, L.
Chen, X. Li, J. P. Cheng, J. Org. Chem. 2019, 84, 7786–
7795; j) J. Chen, B. Q. He, P. Z. Wang, X. Y. Yu, Q. Q.
Zhao, J. R. Chen, W. J. Xiao, Org. Lett. 2019, 21, 4359–
4364; k) L. Tian, S. Gao, R. Wang, Y. Li, C. Tang, L.
Shi, J. Fu, Chem. Commun. 2019, 55, 5347–5350; l) Q.-
Q. Min, N. Li, G.-L. Chen, F. Liu, Org. Chem. Front.
2019, 6, 1200–1204; m) Z. Yin, J. Rabeah, A. Bruckner,
X. F. Wu, Org. Lett. 2019, 21, 1766–1769; n) Y. He, J.
Lou, K. Wu, H. Wang, Z. Yu, J. Org. Chem. 2019, 84,
2178–2190; o) X. Y. Yu, Q. Q. Zhao, J. Chen, J. R.
Chen, W. J. Xiao, Angew. Chem. Int. Ed. 2018, 57,
15505–15509; Angew. Chem. 2018, 130, 15731–15735;
p) L. Yang, P. Gao, X. H. Duan, Y. R. Gu, L. N. Guo,
Org. Lett. 2018, 20, 1034–1037; q) B. Zhao, Z. Shi,
Angew. Chem. Int. Ed. 2017, 56, 12727–12731; Angew.
Chem. 2017, 129, 12901–12905; r) J. Wu, J. Y. Zhang, P.
Gao, S. L. Xu, L. N. Guo, J. Org. Chem. 2018, 83, 1046–
1055.
[10] a) M. L. Vazquez, N. Kaila, J. W. Strohbach, J. D.
Trzupek, M. F. Brown, M. E. Flanagan, M. J. Mitton-Fry,
T. A. Johnson, R. E. TenBrink, E. P. Arnold, A. Basak,
S. E. Heasley, S. Kwon, J. Langille, M. D. Parikh, S. H.
Griffin, J. M. Casavant, B. A. Duclos, A. E. Fenwick,
T. M. Harris, S. Han, N. Caspers, M. E. Dowty, X. Yang,
M. E. Banker, M. Hegen, P. T. Symanowicz, L. Li, L.
Wang, T. H. Lin, J. Jussif, J. D. Clark, J. B. Telliez, R. P.
Robinson, R. Unwalla, J. Med. Chem. 2018, 61, 1130–
1152; b) V. A. Palchykov, R. M. Chabanenko, V. V.
Konshin, V. V. Dotsenko, S. G. Krivokolysko, E. A.
Chigorina, Y. I. Horak, R. Z. Lytvyn, A. A. Vakhula,
M. D. Obushak, A. V. Mazepa, New J. Chem. 2018, 42,
1403–1412; c) W. A. Carroll, R. J. Altenbach, H. Bai,
J. D. Brioni, M. E. Brune, S. A. Buckner, C. Cassidy, Y.
Chen, M. J. Coghlan, A. V. Daza, I. Drizin, T. A. Fey, M.
Fitzgerald, M. Gopalakrishnan, R. J. Gregg, R. F. Henry,
M. W. Holladay, L. L. King, M. E. Kort, P. R. Kym, I.
Milicic, R. Tang, S. C. Turner, K. L. Whiteaker, L. Yi, H.
Zhang, J. P. Sullivan, J. Med. Chem. 2004, 47, 3163–
3179; d) T. Komine, A. Kojima, Y. Asahina, T. Saito, H.
Takano, T. Shibue, Y. Fukuda, J. Med. Chem. 2008, 51,
6558–6562; e) E. Nizi, A. Sferrazza, D. Fabbrini, V.
Nardi, M. Andreini, R. Graziani, N. Gennari, A.
Bresciani, G. Paonessa, S. Harper, Bioorg. Med. Chem.
Lett. 2018, 28, 1540–1544; f) J. Chen, C. Yi, S. Wang, S.
Wu, S. Li, D. Hu, B. Song, Bioorg. Med. Chem. Lett.
2019, 29, 1203–1210; g) J. D. Buynak, V. R. Doppalapu-
di, G. Adam, Bioorg. Med. Chem. Lett. 2000, 10, 853– [17] a) X. Gong, X. Li, W. Xie, J. Wu, S. Ye, Org. Chem.
857; h) R. Recio, E. Vengut-Climent, B. Mouillac, H.
Orcel, M. Lopez-Lazaro, J. M. Calderon-Montano, E.
Alvarez, N. Khiar, I. Fernandez, Eur. J. Med. Chem.
2017, 138, 644–660.
Front. 2019, 6, 1863–1867; b) Y. Meng, M. Wang, X.
Jiang, Angew. Chem. Int. Ed. 2020, 59, 1346–1353;
Angew. Chem. 2020, 132, 1362–1369; c) F. S. He, Y.
Yao, W. Xie, J. Wu, Adv. Synth. Catal. 2020, 362, 4744–
4748; d) X. Wang, Y. Kuang, S. Ye, J. Wu, Chem.
Commun. 2019, 55, 14962–14964; e) X. Gong, M. Yang,
J.-B. Liu, F.-S. He, X. Fan, J. Wu, Green Chem. 2020,
22, 1906–1910; f) X. Gong, M. Wang, S. Ye, J. Wu, Org.
Lett. 2019, 21, 1156–1160; g) F. S. He, X. Gong, P.
Rojsitthisak, J. Wu, J. Org. Chem. 2019, 84, 13159–
13163; h) H. Zhu, Y. Shen, D. Wen, Z. G. Le, T. Tu,
Org. Lett. 2019, 21, 974–979; i) X. Gong, M. Yang, J.-B.
[11] a) D. R. Gauthier, Jr., N. Yoshikawa, Org. Lett. 2016, 18,
5994–5997; b) T. Martzel, J.-F. Lohier, A.-C. Gaumont,
J.-F. Brière, S. Perrio, Adv. Synth. Catal. 2017, 359, 96–
106; c) R. J. Brooks, C. A. Bunton, J. M. Hellyer, J. Org.
Chem. 1973, 38, 2151–2156; d) A. Padmaja, T. Payani,
G. D. Reddy, V. Padmavathi, Eur. J. Med. Chem. 2009,
44, 4557–4566.
[12] G. A. N. Felton, Tetrahedron Lett. 2008, 49, 884–887.
Adv. Synth. Catal. 2021, 363, 1–7
5
© 2021 Wiley-VCH GmbH
��
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UPDATES
asc.wiley-vch.de
Liu, F.-S. He, J. Wu, Org. Chem. Front. 2020, 7, 938–
Chem. 2020, 2020, 1274–1287; f) P. Bisseret, N.
Blanchard, Org. Biomol. Chem. 2013, 11, 5393–5398;
g) M. Willis, A. Deeming, E. Emmett, C. Richards-
Taylor, Synthesis. 2014, 46, 2701–2710; h) D. Zheng, J.
Wu, Sulfur Dioxide Insertion Reactions for Organic
Synthesis, Springer, Singapore, 2017.
943; j) X. Wang, M. Yang, Y. Kuang, J. B. Liu, X. Fan,
J. Wu, Chem. Commun. 2020, 56, 3437–3440; k) K.
Chen, W. Chen, B. Han, W. Chen, M. Liu, H. Wu, Org.
Lett. 2020, 22, 1841–1845; l) M. Kumar, R. Ahmed, M.
Singh, S. Sharma, T. Thatikonda, P. P. Singh, J. Org.
Chem. 2020, 85, 716–725; m) G. You, D. Xi, J. Sun, L. [19] a) X. Jiang, B. Zhu, K. Lin, G. Wang, W. K. Su, C. Yu,
Hao, C. Xia, Org. Biomol. Chem. 2019, 17, 9479–9488;
n) S. Ye, J. Wu, Chem. Commun. 2012, 48, 10037–
10039; o) S. Ye, M. Yang, J. Wu, Chem. Commun. 2020,
56, 4145–4155; p) S. Ye, G. Qiu, J. Wu, Chem. Commun.
2019, 55, 1013–1019.
Org. Biomol. Chem. 2019, 17, 2199–2203; b) X. Jiang,
L. Yang, Z. Ye, X. Du, L. Fang, Y. Zhu, K. Chen, J. Li,
C. Yu, Eur. J. Org. Chem. 2020, 2020, 1687–1694; c) X.
Zheng, T. Zhong, L. Zhang, J. Chen, Z. Chen, X. Jiang,
C. Yu, Eur. J. Org. Chem. 2020, 2020, 4534–4541; d) B.
Zhu, H. Han, W. K. Su, C. Yu, X. Jiang, Adv. Synth.
Catal. 2020, 363, 484–489.
[18] Some reviews on the insertion of sulfur dioxide: a) E. J.
Emmett, M. C. Willis, Asian J. Org. Chem. 2015, 4,
602–611; b) G. Qiu, K. Zhou, L. Gao, J. Wu, Org. Chem. [20] CCDC-2073119 (3c) contains the supplementary crystal-
Front. 2018, 5, 691–705; c) G. Qiu, L. Lai, J. Cheng, J.
Wu, Chem. Commun. 2018, 54, 10405–10414; d) S. Ye,
D. Zheng, J. Wu, G. Qiu, Chem. Commun. 2019, 55,
2214–2217; e) S. Ye, X. Li, W. Xie, J. Wu, Eur. J. Org.
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.
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Iron-Catalyzed Three-Component Cyanoalkylsulfonylation of
2,3-Allenoic Acids, Sulfur Dioxide, and Cycloketone Oxime
Esters: Access to Cyanoalkylsulfonylated Butenolides
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X. Zheng, T. Zhong, X. Yi, Q. Shen, C. Yin, L. Zhang, J.
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