Trifluoromethylfluorosulfonylation of Unactivated Alkenes Using Readily Available Ag(O2CCF2SO2F) and N-Fluorobenzenesulfonimide

Article abstract of DOI:10.1002/anie.201709663

Presented is a novel intermolecular radical trifluoromethylfluorosulfonylation of unactivated alkenes under mild reaction conditions with good functional-group tolerance in the most atom-economic manner by using readily available Ag(O₂CCF₂SO₂F) and N-fluorobenzenesulfonimide (NFSI). Both the trifluoromethyl and sulfonyl groups in the products originate from Ag(O₂CCF₂SO₂F).

Full text of DOI:10.1002/anie.201709663

Angewandte
Communications
Chemie
International Edition: DOI: 10.1002/anie.201709663
German Edition: DOI: 10.1002/ange.201709663
Radicals
Trifluoromethylfluorosulfonylation of Unactivated Alkenes Using
Readily Available Ag(O2CCF2SO2F) and N-fluorobenzenesulfonimide
Yongan Liu, Hao Wu, Yong Guo, Ji-Chang Xiao, Qing-Yun Chen,* and Chao Liu*
Abstract: Presented is a novel intermolecular radical trifluor-
omethylfluorosulfonylation of unactivated alkenes under mild
reaction conditions with good functional-group tolerance in
the most atom-economic manner by using readily available
Ag(O2CCF2SO2F) and N-fluorobenzenesulfonimide (NFSI).
Both the trifluoromethyl and sulfonyl groups in the products
originate from Ag(O2CCF2SO2F).
Scheme 1. Our representative tetrafluoroethane b-sultone-derived fluo-
rinating reagents.
The selective introduction of fluorine-containing groups into
organic molecules can dramatically alter their physical,
chemical, and biological properties and has received consid-
erable attention.[1] As important groups in organofluorine
chemistry in the recent years, both trifluoromethyl (CF3)[2]
and fluorosulfonyl (SO2F)[3] groups have been widely ultilized
throughout the field of medicinal chemistry, chemical biology,
materials, and organic synthesis because of their unique
properties. In contrast, direct radical-mediated olefinic 1,2-
difunctionalization initiated by intermolecular addition of
a variety of radical precusors to alkenes, and trapping by an
appropriate external nucleophile, has recently developed into
an attractive and powerful method for simultaneously incor-
porating two functional groups into a carbon–carbon double
bond for the generation of various highly functionalized
skeletons in organic synthesis.[4,5] It would be highly desirable
to simultaneously introduce both CF3 and SO2F groups into
small molecules in one step by radical 1,2-difunctionalization
of alkenes. To the best of our knowledge, the efficient
synthesis of CF3-containing alkyl sulfonyl fluorides has not
been described to date.
release of CO2 and SO2 molecules. In some cases, it was
suspected that SO2, generated in situ during the reactions,
might have a negative effect on the desired reactions. To
address this issue and utilize the tetrafluoroethane b-sultone-
derived reagents in a more atom-economic manner, it is
desirable to use SO2, generated in situ, to generate some
useful functional groups, including the SO2F group. As a part
of our program for the application of various tetrafluoro-
ethane b-sultone-derived reagents,[6–9] and also inspired by
important advances in the radical-based sulfur dioxide
insertion reactions,[10] we proposed to develop a direct olefinic
intermolecular radical trifluoromethylfluorosulfonylation
reaction, thus focusing on the efficient and atom-economic
ultilization of SO2 generated in situ from various fluorosul-
fonyl difluoroacetic acid metal salts, M(O2CCF2SO2F)n.
Herein, we present the results.
We envisioned M(O2CCF2SO2F)n easily decomposing into
a MCF3 species under the reaction conditions with the
extrusion of CO2 and SO2 molecules (Scheme 2). Under
appropriate reaction conditions, the MCF3 species generates
a CF3 radical which adds to an alkene to provide the new alkyl
We have had a long-standing interest in various perfluor-
oalkylation reactions, and have been focusing on developing
new
difluoromethylation
and
trifluoromethylation
approaches, particularly by using inexpensive and readily
available tetrafluoroethane b-sultone-based fluorinating
derivatives as reagents (Scheme 1).[6,7] Very recently, we
radical A. A may trap SO2, released in situ from
M(O2CCF2SO2F)n, to form the new sulfonyl radical B. Its
straightforward reaction with an electrophilic fluorination
reagent results in the desired trifluoromethylfluorosulfonyla-
tion product.
To test the feasibility of our hypothesis, we began to
explore the reactivity of various M(O2CCF2SO2F)n with 4-
reported
a
new
trifluoromethylating
reagent,
Cu(O2CCF2SO2F)2, for efficiently trifluoromethylating a vari-
ety of haloarenes.[8] The reaction pathway has been proposed
to involve the formation of the key intermediate CuCF3
species by its decarboxylation and decomposition with the
[*] Y. Liu, Dr. H. Wu, Prof. Dr. Y. Guo, Prof. Dr. J.-C. Xiao,
Prof. Dr. Q.-Y. Chen, Prof. Dr. C. Liu
Key Laboratory of Organofluorine Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Sciences
345 Lingling Road, 200032, Shanghai (China)
E-mail: chenqy@sioc.ac.cn
chaoliu@sioc.ac.cn
Supporting information for this article can be found under:
https://doi.org/10.1002/anie.201709663.
Scheme 2. Proposed intermolecular radical trifluoromethylfluorosulfo-
nylation of alkenes.
Angew. Chem. Int. Ed. 2017, 56, 1 – 5
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1
These are not the final page numbers!

Angewandte
Communications
Chemie
phenyl-1-butene (1a) as the model substrate and N-fluoro-
benzenesulfonimide (NFSI) as the electrophilic fluorination
reagent. As can be seen in Table 1, Cu(O2CCF2SO2F)2 was
first tested in the intermolecular radical trifluoromethylfluor-
osulfonylation reaction. Although the complete transforma-
tion of Cu(O2CCF2SO2F)2 was observed, the reaction did not
provide the desired trifluoromethylfluorosulfonylation prod-
uct 2a at either room temperature or 808C (entry 1).
Fortunately, replacement of Cu(O2CCF2SO2F)2 with
Ag(O2CCF2SO2F) under similar reaction conditions did
result in the formation of the desired product 2a in good
yield, thus showing the important role of the metal counter
cation in the reaction (entry 2). It is worth mentioning that
Ag(O2CCF2SO2F) is easily prepared on large scale in 95%
yield from the facile reaction of FSO2CF2COOH with
Ag2CO3, and it is a stable white powder which can be stored
and used conveniently.[11] A survey on the reaction temper-
atures showed that higher reaction temperatures had negative
effects and room temperature was the best choice for the
reaction temperature (entries 2–5). Later, several common
solvents were screened and it was found that DMF and
acetone gave lower yields of 2a (entries 6 and 7), while the
other solvents tested led to no formation of 2a (entry 8). In
addition, using water as a co-solvent was harmful for the
reaction and resulted in no formation of the desired product
(entry 9). It should be mentioned that utilizing NFSI as the
electrophilic fluorination reagent played a key role in the
reaction, as significantly lower yield of the desired product
was observed by using other electrophilic fluorination
reagents (entry 10). Finally, increasing the amounts of
Ag(O2CCF2SO2F) or NFSI only provided slightly better
yields of 2a, thus demonstrating the high efficiency of the
reaction as well (entries 11 and 12).
With the optimal reaction conditions identified (Table 1,
entry 4), the substrate scope of the intermolecular radical
trifluoromethylfluorosulfonylation reaction was examined
and the results are summarized in Table 2. A wide range of
unactivated terminal alkenes were applicable to the reaction
and provided the CF3-substituted alkyl sulfonyl fluoride in
moderate to good yields. A series of functional groups,
including ether (2c–g, 2ee), ester (2h–u, 2aa, 2bb, 2 ff),
heterocyclic (2r–t), halogen (2l, 2y, 2z, 2aa), sulfonic ester
Table 2: Substrate scope of the intermolecular trifluoromethylfluorosul-
fonylation of various alkenes.[a]
Table 1: Optimization of reaction conditions for trifluoromethylfluoro-
sulfonylation of alkenes.[a]
Entry Conditions
Yield [%][b]
1
2
3
4
5
6
7
8
Cu(O2CCF2SO2F)2, CH3CN, RT or 808C
0
66
73
86
84
20
28
0
Ag(O2CCF2SO2F), CH3CN, 808C
Ag(O2CCF2SO2F), CH3CN, 508C
Ag(O2CCF2SO2F), CH3CN, RT
Ag(O2CCF2SO2F), CH3CN, 08C
Ag(O2CCF2SO2F), DMF, RT
Ag(O2CCF2SO2F), acetone, RT
Ag(O2CCF2SO2F), solvent: THF, DCM, DCE, benzene
or EA, RT
9
Ag(O2CCF2SO2F), CH3CN/H2O (9:1 v/v), RT
0
<20
88
10[c] Ag(O2CCF2SO2F), CH3CN, RT
11[d] Ag(O2CCF2SO2F), CH3CN, RT
12[e] Ag(O2CCF2SO2F), CH3CN, RT
88
[a] Reaction conditions: the alkene 1 (0.3 mmol, 1.0 equiv),
Ag(O2CCF2SO2F) (0.45 mmol, 1.5 equiv), and NFSI (0.36 mmol,
1.2 equiv) in CH3CN (4.5 mL) at room temperature under an Ar
atmosphere for 3 hours. Yields of isolated products were reported.
[b] Reaction conditions: the alkene 1 (0.3 mmol, 1.0 equiv),
Ag(O2CCF2SO2F) (0.6 mmol, 2.0 equiv), and NFSI (0.48 mmol,
1.6 equiv) in CH3CN (4.5 mL) at room temperature under an Ar
atmosphere for 3 hours. [c] Yields were determined by 19F NMR
spectroscopy with 1-methoxy-4-(trifluoromethoxy)benzene as an internal
standard. Thermal ellipsoids of the X-ray crystal structure[15] of 3u shown
at 50% probability.
[a] Reaction conditions: 1a (0.2 mmol, 1.0 equiv), M(O2CCF2SO2F)n
(0.3 mmol, 1.5 equiv), NFSI (0.24 mmol, 1.2 equiv) in solvent (3 mL)
under Ar atmosphere for 3 hours. [b] Yields were determined by 19F NMR
spectroscopy with 1-methoxy-4-(trifluoromethoxy)benzene as an internal
standard. [c] Selectfluor or N-fluoropyridinium pyridine heptafluorodi-
borate (0.24 mmol, 1.2 equiv) was used instead of NFSI.
[d] Ag(O2CCF2SO2F) (0.4 mmol, 2.0 equiv) was used. [e] NFSI
(0.3 mmol, 1.5 equiv) was used. DCE=1,2-dichloroethane, DCM=di-
chloromethane, DMF=N,N-dimethylformamide, EA=ethyl acetate,
THF=tetrahydrofuran.
2
www.angewandte.org
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2017, 56, 1 – 5
These are not the final page numbers!

Angewandte
Communications
Chemie
(2y), ketone (2ee), phthalimide (2u, 2v), nitro (2p), cyano
(2bb), and phosphoryl (2x) moieties, were well tolerated
under the reaction conditions, and might be attributed to the
mild reaction conditions employed. Notably, 1,1-disubstituted
terminal alkenes are also suitable for the trifluoromethyl-
fluorosulfonylation reaction, thus providing moderate yields
of the corresponding trifluoromethylfluorosulfonylation
products (2aa, 2bb). It is interesting that 1,2-disubstituted
cyclic internal alkenes can also be subjected to the trans-
formation, thus generating the desired products in acceptable
yields (2cc, 2dd). However, styrene-type alkenes and elec-
tron-poor alkenes are not good candidates for the trifluor-
omethylfluorosulfonylation reaction, thus suggesting a pro-
found effect of electronic properties of the alkenes (2gg,
2hh). In addition, terminal alkenes derived from relatively
complex molecules 4-methylumbelliferone and estrone were
compatible with the reaction conditions and yielded the
desired products in satisfactory yields, which demonstrates
the potential of the trifluoromethylfluorosulfonylation reac-
tion in late-stage functionalization (2ee, 2 ff). Moreover, the
trifluoromethylfluorosulfonylation reaction of the alkene 1v
on gram scale was carried out to study the possible scalability
of the reactions. It was found that the reaction proceeded
smoothly and yielded the desired product in 81% yield (2v),
thus exhibiting excellent scalability of the trifluoromethyl-
fluorosulfonylation reaction. In addition, further transforma-
tion of the trifluoromethylfluorosulfonylation products was
preliminarily investigated. As demonstrated in Equa-
tions (1)–(3), the reactions of the trifluoromethylfluorosulfo-
nylation product 2v with either MeONa, piperidine, or
NH3·H2O conveniently afforded the corresponding and
potentially useful sulfonate 3 and sulfonamides 4 and 5 in
good yields. And thus conveniently install two important
functional groups into the original lead compounds or drugs.
d = À87.8 ppm, which were considered to represent AgCF3
and AgSO2CF3,[12] respectively, and is consistent with the
literature.[13] After 3 hours, the signal of AgCF3 almost
disappeared while the intensity of the signal of AgSO2CF3
was enhanced, and observation that might be attributed to the
reaction of AgCF3 with SO2 generated in situ from
Ag(O2CCF2SO2F). Notably, the addition of NFSI into the
resulting reaction mixture led to the formation of CF3SO2F
because of the facile fluorination of sulfinate AgSO2CF3 by
NFSI.[14] Next, we investigated the stepwise reaction of
Ag(O2CCF2SO2F) in acetonitrile with 1a and NFSI
[Eq. (5)]. It was found that the reaction of 1a and NFSI
with the 15 minute decomposition reaction mixture of
Ag(O2CCF2SO2F) in acetonitrile afforded 49% yield of the
desired product 2a together with 21% yield of CF3SO2F,
while the 3 hour decomposition reaction mixture provided
a trace amount of 2a, and 41% yield of CF3SO2F was
obtained as the main product. These experimental results
suggest that AgCF3 generated in situ from Ag(O2CCF2SO2F)
may be the key CF3 radical source. Finally, addition of the new
alkyl radical, formed by addition of the CF3 radical to the
alkene, to sulfur dioxide, and subsequent reaction with NFSI
generate SO2F groups in the desired products.[14,10b] It should
be mentioned that Reiser et al. recently reported an elegant
visible-light-mediated trifluoromethylchlorosulfonylation of
unactivated alkenes with CF3SO2Cl in the presence of
a copper catalyst, and it was considered to proceed by an
inner-sphere radical mechanism,[5a] which is different from
ours.
In conclusion, we have developed, for the first time,
a novel intermolecular radical trifluoromethylfluorosulfony-
lation reaction of unactivated alkenes with the readily
available Ag(O2CCF2SO2F) and NFSI under mild reaction
conditions with good functional-group compatibility. The
reaction mechanism involves the addition of a CF3 radical,
generated from a AgCF3 species, to the alkene substrate to
generate an alkyl radical intermediate, sulfur dioxide inser-
tion, and subsequent fluorination reaction with NFSI. Nota-
bly, both CF3 and sulfonyl groups originate from
Ag(O2CCF2SO2F). Further investigation on the development
of other fluoroalkylfluorosulfonylation, or direct fluorosulfo-
nylation reactions is in progress.
To gain more insights into the reaction mechanism
(Scheme 2), several control experiments were conducted on
1a. First, several radical inhibition and radical-clock exper-
imental results demonstrate that the reaction may proceed
through a radical pathway and possibly involve a CF3 radical
species (see the Supporting Information for details). Second,
the decomposition of Ag(O2CCF2SO2F) itself in acetonitrile
and its stepwise reactions with either 1a or NFSI were
monitored and investigated by 19F NMR analysis [Eqs. (4)
and (5); see the Supporting Information for details]. 19F NMR
spectra of the reaction mixture of Ag(O2CCF2SO2F) in
acetonitrile at room temperature under an Ar atmosphere
for 15 minutes showed signals at d = À22.2, À24.7 ppm, and
Acknowledgements
The authors gratefully acknowledge the financial support
from the National Natural Science Foundation of China (Nos.
21421002, 21302207, 21672239, 21737004), the National Basic
Angew. Chem. Int. Ed. 2017, 56, 1 – 5
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
3
These are not the final page numbers!

Angewandte
Communications
Chemie
81, 7139; c) S. K. Pagire, S. Paria, O. Reiser, Org. Lett. 2016, 18,
2106; d) Z. Wu, R. Ren, C. Zhu, Angew. Chem. Int. Ed. 2016, 55,
10821; Angew. Chem. 2016, 128, 10979; e) Y. Xu, Z. Wu, J. Jiang,
Z. Ke, C. Zhu, Angew. Chem. Int. Ed. 2017, 56, 4545; Angew.
Chem. 2017, 129, 4616; f) Z. Wu, D. Wang, Y. Liu, L. Huan, C.
Zhu, J. Am. Chem. Soc. 2017, 139, 1388; g) Z. L. Li, X. H. Li, N.
Wang, N. Y. Yang, X.-Y. Liu, Angew. Chem. Int. Ed. 2016, 55,
15100; Angew. Chem. 2016, 128, 15324; h) L. Li, Z. L. Li, F. L.
Wang, Z. Guo, Y. F. Cheng, N. Wang, X. W. Dong, C. Fang, J. Liu,
C. Hou, B. Tan, X.-Y. Liu, Nat. Commun. 2016, 7, 13852; i) J.-S.
Lin, X.-Y. Dong, T.-T. Li, N.-C. Jiang, B. Tan, X.-Y. Liu, J. Am.
Chem. Soc. 2016, 138, 9357; j) L. Li, Z. L. Li, Q. S. Gu, N. Wang,
X.-Y. Liu, Sci. Adv. 2017, 3, e1701487; k) J. S. Lin, F. L. Wang,
X. Y. Dong, W. W. He, Y. Yuan, S. Chen, X.-Y. Liu, Nat.
Commun. 2017, 8, 14841; l) Y. F. Cheng, X. Y. Dong, Q. S. Gu,
Z. L. Yu, X.-Y. Liu, Angew. Chem. Int. Ed. 2017, 56, 8883;
Angew. Chem. 2017, 129, 9009; m) D. Zhu, X. Shao, X. Hong, L.
Lu, Q. Shen, Angew. Chem. Int. Ed. 2016, 55, 15807; Angew.
Chem. 2016, 128, 16039; n) Q. Zhao, L. Lu, Q. Shen, Angew.
Chem. Int. Ed. 2017, 56, 11575; Angew. Chem. 2017, 129, 11733.
[6] a) Q. Y. Chen, J. Fluorine Chem. 1995, 72, 241; b) C. P. Zhang,
Q. Y. Chen, Y. Guo, J. C. Xiao, Y. C. Gu, Chem. Soc. Rev. 2012,
41, 4536; c) C. P. Zhang, Q. Y. Chen, Y. Guo, J. C. Xiao,
Tetrahedron 2013, 69, 10955; d) C. P. Zhang, Q. Y. Chen, Y.
Guo, J. C. Xiao, Y. C. Gu, Coord. Chem. Rev. 2014, 261, 28.
[7] For a nice review on the application of our trifluoromethylation
reagent FSO2CF2COOMe, see: S. L. Clarke, G. P. McGlacken,
Chem. Eur. J. 2017, 23, 1219.
Research Program of China (2012CB821600), and Science
and Technology Commission of Shanghai Municipality
(17ZR1437000).
Conflict of interest
The authors declare no conflict of interest.
Keywords: alkenes · fluorine · radicals · reaction mechanisms ·
synthetic methods
[1] a) K. Mꢀller, C. Faeh, F. Diederich, Science 2007, 317, 1881;
b) J. P. Bꢁguꢁ, D. Bonnet-Delpon, Bioorganic and Medicinal
Chemistry of Fluorine, Wiley, Hoboken, 2008; c) I. Ojima,
Fluorine in Medicinal Chemistry and Chemical Biology, Wiley-
Blackwell, Hong Kong, 2009; d) W. K. Hagmann, J. Med. Chem.
2008, 51, 4359; e) S. Purser, P. R. Moore, S. Swallow, V.
Gouverneur, Chem. Soc. Rev. 2008, 37, 320; f) J. Wang, M.
Sꢂnchez-Rosellꢃ, J. L. AceÇa, C. D. Pozo, A. E. Sorochinsky, S.
Fustero, V. A. Soloshonok, H. Liu, Chem. Rev. 2014, 114, 2432.
[2] For leading reviews on various trifluoromethylation reactions,
see: a) O. A. Tomashenko, V. V. Grushin, Chem. Rev. 2011, 111,
4475; b) S. Roy, B. T. Gregg, G. W. Gribble, V. D. Le, S. Roy,
Tetrahedron 2011, 67, 2161; c) T. Liu, Q. Shen, Eur. J. Org. Chem.
2012, 6679; d) L. Chu, F. L. Qing, Acc. Chem. Res. 2014, 47, 1513;
e) X. Liu, C. Xu, M. Wang, Q. Liu, Chem. Rev. 2015, 115, 683;
f) C. Ni, M. Hu, J. Hu, Chem. Rev. 2015, 115, 765; g) C. Alonso,
E. M. Marigorta, G. Rubiales, F. Palacios, Chem. Rev. 2015, 115,
1847; h) Q. Liu, C. Ni, J. Hu, Nat. Sci. Rev. 2017, 4, 303.
[3] For a comprehensive review on sulfur(VI) fluoride exchange
(SuFEx) chemistry, see: a) J. Dong, L. Krasnova, M. G. Finn,
K. B. Sharpless, Angew. Chem. Int. Ed. 2014, 53, 9430; Angew.
Chem. 2014, 126, 9584. For recent examples on the application of
SuFEx process, see: b) J. Dong, K. B. Sharpless, L. Kwisnek, J. S.
Oakdale, V. V. Fokin, Angew. Chem. Int. Ed. 2014, 53, 9466;
Angew. Chem. 2014, 126, 9620; c) B. Gao, L. Zhang, Q. Zheng, F.
Zhou, L. M. Klivansky, J. Lu, Y. Liu, J. Dong, P. Wu, K. B.
Sharpless, Nat. Chem. 2017, 9, 1083.
[8] G. Zhao, H. Wu, Z. Xiao, Q. Y. Chen, C. Liu, RSC Adv. 2016, 6,
50250.
[9] a) C. Liu, Q. Y. Chen, Eur. J. Org. Chem. 2005, 3680; b) C. Liu,
D. M. Shen, Q. Y. Chen, J. Am. Chem. Soc. 2007, 129, 5814.
[10] For recent reviews on sulfur dioxide insertion reactions, see:
a) E. J. Emmett, M. C. Willis, Asian J. Org. Chem. 2015, 4, 602;
b) D. Zheng, J. Wu, Sulfur Dioxide Insertion Reactions for
Organic Chemisty, Springer, Singapore, 2017.
[11] Ag(O2CCF2SO2F) was conveniently prepared according to our
previous report: D. B. Su, R. X. Zhu, Z. M. Qiu, Q. Y. Chen,
Acta Chim. Sin. 1990, 48, 596. For details, see the Supporting
Information.
[12] The AgCF3 species [AgCF3·CH3CN + Ag(CF3)2À] generated
from TMSCF3 and AgF shows similar signals in the 19F NMR
spectra to those of AgCF3 generated from Ag(O2CCF2SO2F).
For details, see the Supporting Information. And the 19F NMR
chemical shift of NaSO2CF3 was used as the reference to that of
AgSO2CF3.
[13] Y. Zeng, L. Zhang, Y. Zhao, C. Ni, J. Zhao, J. Hu, J. Am. Chem.
Soc. 2013, 135, 2955, and references therein.
[14] A. T. Davies, J. M. Curto, S. W. Bagley, M. C. Willis, Chem. Sci.
2017, 8, 1233.
[4] For representative reviews on radical-mediated olefinic 1,2-
difunctionalization, see: a) H. Egami, M. Sodeoka, Angew.
Chem. Int. Ed. 2014, 53, 8294; Angew. Chem. 2014, 126, 8434;
b) M. Y. Cao, X. Ren, Z. Lu, Tetrahedron Lett. 2015, 56, 3732;
c) A. Studer, D. P. Curran, Angew. Chem. Int. Ed. 2016, 55, 58;
Angew. Chem. 2016, 128, 58; d) A. J. Clark, Eur. J. Org. Chem.
2016, 2231; e) S. Kindt, M. R. Heinrich, Synthesis 2016, 48, 1597;
f) O. Reiser, Acc. Chem. Res. 2016, 49, 1990; g) X. W. Lan, N. X.
Wang, Y. Xing, Eur. J. Org. Chem. 2017, 39, 5821.
[15] CCDC 1562502 (2u) contain the supplementary crystallographic
data for this paper. These data can be obtained free of charge
from The Cambridge Crystallographic Data Centre.
[5] For selected recent examples on radical 1,2-difunctionalization
of unactivated alkenes, see: a) D. B. Bagal, G. Kachkovskyi, M.
Knorn, T. Rawner, B. M. Bhanage, O. Reiser, Angew. Chem. Int.
Ed. 2015, 54, 6999; Angew. Chem. 2015, 127, 7105; b) T. Rawner,
M. Knorn, E. Lutsker, A. Hossain, O. Reiser, J. Org. Chem. 2016,
Manuscript received: September 18, 2017
Version of record online: && &&, &&&&
4
www.angewandte.org
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2017, 56, 1 – 5
These are not the final page numbers!

Angewandte
Communications
Chemie
Communications
Radicals
Y. Liu, H. Wu, Y. Guo, J.-C. Xiao,
Q.-Y. Chen,* C. Liu*
&&&& — &&&&
Making it functional: The title reaction
proceeds using the readily available
Ag(O2CCF2SO2F) and N-fluorobenzene-
sulfonimide (NFSI) under mild reaction
conditions, and features good functional-
group tolerance. The CF3 group in the
product originates from a AgCF3 species
Trifluoromethylfluorosulfonylation of
Unactivated Alkenes Using Readily
Available Ag(O2CCF2SO2F) and N-
fluorobenzenesulfonimide
formed from Ag(O2CCF2SO2F), and the in
situ generated SO2 is trapped and con-
verted into a sulfonyl group, thus dem-
onstrating the atom-economy of the
reaction.
Angew. Chem. Int. Ed. 2017, 56, 1 – 5
ꢀ 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
5
These are not the final page numbers!