Copper-Catalyzed TBHP-Mediated Radical Cross-Coupling Reaction of Sulfonylhydrazides with Thiols Leading to Thiosulfonates

Article abstract of DOI:10.1021/acs.joc.7b01121

A tert-butyl hydroperoxide (TBHP)-mediated coupling of sulfonylhydrazides with thiols catalyzed by CuBr₂ to afford thiosulfonates via a radical process is described.

Full text of DOI:10.1021/acs.joc.7b01121

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Note
Copper-catalyzed TBHP-mediated radical cross-coupling reaction
of sulfonylhydrazides with thiols leading to thiosulfonates
Guo-Yu Zhang, Shuai-Shuai Lv, Adedamola Shoberu, and Jian-Ping Zou
J. Org. Chem., Just Accepted Manuscript • Publication Date (Web): 16 Aug 2017
Downloaded from http://pubs.acs.org on August 16, 2017
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Copper-catalyzed TBHP-mediated radical cross-coupling reaction of
sulfonylhydrazides with thiols leading to thiosulfonates
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GuoꢀYu Zhang, ShuaiꢀShuai Lv, Adedamola Shoberu, JianꢀPing Zou*
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Key Laboratory of Organic Synthesis of Jiangsu Province,,College of Chemistry and Chemical Engineering,
Soochow University, 199 Renai Street, Suzhou, Jiangsu 215123, China. jpzou@suda.edu.cn
ABSTRACT: A tertꢀbutyl hydroperoxide (TBHP)–mediated coupling of sulfonylhydrazides with
thiols catalyzed by CuBr2 to afford thiosulfonates via a radical process is described.
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Oxidative radical crossꢀcoupling reactions are becoming increasingly important for the
construction of carbonꢀcarbon and carbonꢀheteroatom bonds (Scheme 1).1, 2 Most common types of
organic reactions involving free radicals have so far been well studied and understood.3 In contrast,
the oxidative radical crossꢀcoupling reaction still remains underdeveloped due to the issue of poor
selectivity caused by the inherent activity of radicals. Therefore, the challenge is how to conduct
these reactions in a highly efficient and selective manner.1c, 1e In general terms, only the radical
coupling between a persistent radical (longꢀlived) and a transient radical would lead to a selective
bond formation.4
5a
Sulfonylhydrazides are important intermediates in organic synthesis.
They are easily
transformed into sulfonyl radicals that can further add to unsaturated carbonꢀcarbon bonds.5bꢀk To the
best of our knowledge however, the selective crossꢀcoupling of sulfonylhydrazides with thiols has
not been reported. According to the previous reports on thiyl radical reactions,6 we hypothesized that
a radical crossꢀcoupling strategy for the construction of sulfur−sulfone bond could be developed. We
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envisioned that a thiyl radical can be generated from thiol and then stabilized by a suitable transition
metal catalyst (transient radical) which can subsequently couple with a persistent sulfonyl radical.
Thiosulfonates have found widespread use as reagents or intermediates, so far several protocols for
synthesis of thiosulfonates have been developed through the oxidation of thiols and disulfides, the
crossꢀcoupling reaction of sulfinic acid salts with disulfides or sulfonyl chlorides with thiols.7 Herein,
a new copperꢀcatalyzed selective radical crossꢀcoupling between sulfonylhydrazides and thiols for
the formation of thiosulfonates is described.
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Scheme 1. Oxidative radical cross-coupling reactions
We began our investigation by focusing on the reaction between 4ꢀmethylbenzenesulfonyl
hydrazide (1a) and benzenethiol (2a, 2 equiv.) in the presence of CuBr2 (10 mol%) and tertꢀbutyl
hydroperoxide (TBHP, 7.5 equiv) in CH3CN at room temperature (Table 1, entry 1). We were
pleased to find that 72% yield of product 3a could be obtained after 2 hours. In order to improve the
yield of 3a, other transition metal catalysts were screened. Whereas a similar result was obtained
with CuCl (Table 1, entry 2), the use of other metal catalyst such as FeCl3, AgNO3 and NiCl2 proved
to be detrimental to the reaction. This indicates that only copper catalysts could significantly stabilize
the thiyl radical. It is worthy to note that product 3a was not detected in the absence of a metal
catalyst (Table 1, entry 6). Next, we found that an increase in the temperature led to an increase in
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the yield of 3a, with an optimal yield of 84% at 80 C (Table 1, entries 7ꢀ10). Furthermore, a
variation in the ratio of the amount of 1a and 2a impacted upon the yield negatively (Table 1, entries
11ꢀ13). Also, we discovered that 7.5 equiv. of TBHP was optimal for this reaction (Table 1, entries
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14ꢀ19). Finally, CH3CN remained the solvent of choice as the results obtained with other solvents
were unsatisfactory (Table 1, entries 20ꢀ24).
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Table 1. Optimization of the reaction conditionsa
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With the optimized set of conditions in hand, the scope of this radical crossꢀcoupling reaction was
examined in detail. A variety of substituted benzenethiols were screened and results showed that
both electronꢀwithdrawing and electronꢀdonating substituents on the benzene ring had no influence
on product formation (Table 2). Also, this reaction was insensitive to steric effect as exemplified by
substrates bearing orthoꢀsubstituents (Table 2, 3c, 3g, 3i, 3l and 3p). Substrates containing methoxy
substituent gave relatively lower yields probably due to the partial oxidation of substrates (Table 2,
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3eꢀg). With heterocyclic thiols however, products such as 3q and 3r were formed in lower yields
while alkylthiols gave the corresponding products in moderate yields (Table 2, 3s-u).
Table 2. Scope of thiolsa,b
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Furthermore, the radical crossꢀcoupling reaction was tested over a broad range of
sulfonylhydrazides (Table 3). Again, we found that neither steric (Table 3, 4b, 4i and 4k) nor
electronic effect (Table 3, 4aꢀn) had any significant influence on the yield of products, all of the
sulfonylhydrazides gave the desired products in good yields, indicating that this reaction has good
substituent group tolerance.
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Table 3. Scope of sulfonylhydrazidesa, b
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In order to understand the mechanism of the reaction, a series of control experiments were carried
out (Scheme 2). Initially, a wellꢀknown radical trapping agent, 2,2,6,6ꢀtetramethylpiperidine oxide
(TEMPO), was added to the reaction mixture containing 4ꢀmethylbenzenesulfonylhydrazide (1a) and
benzenethiol (2a) under the optimal conditions. As expected, the reaction was inhibited while the
capture of a thiyl radical by TEMPO was detected by LCꢀMS (Scheme 2(a)). Also, the product
formation was completely suppressed upon the addition of the radical inhibitor BHT to the reaction
(Scheme 2(b)). Furthermore, when 1a was reacted with styrene under the optimal conditions, the
styrene adducts 6a and 6b were detected by LCꢀMS, in which 6b was isolated and confirmed by
NMR and HRMS further (Scheme 2(c)). These results therefore confirmed the involvement of thiyl
and sulfonyl radical intermediates.
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Scheme 2. The control experiments
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On the basis of the results above and literature1e, 2f, a plausible mechanism was proposed as shown
in Scheme 3. Initially, sulfonyl radical 7 could be formed from sulfonylhydrazide 1 via a multiꢀstep
reaction with tertꢀbutoxy radical (tꢀBuO•) or tertꢀbutylperoxy radical (tꢀBuOO•) alongside the
release of a nitrogen molecule. On the other hand, thiyl radical 8 could be generated from the
oxidation of thiol 2 by the tꢀBuO• or tꢀBuOO• radicals, which can further coordinate with the copper
species to form the complex 9. Finally, the sulphurꢀsulfone bond can be formed via the coupling of
sulfonyl radical 7 with complex 9 through intermediate 10 to give thiosulfonate 3. Meanwhile, the
copper species is released for the next cycle.
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Scheme 3. Plausible mechanism
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In conclusion, we have developed a convenient copperꢀcatalyzed TBHPꢀmediated radical crossꢀ
coupling of sulfonylhydrazides with thiols. The procedure is simple, mild, and tolerant to different
functional groups and affords a variety of thiosulfonates in good yields. The reaction proceeded
through the crossꢀcoupling of sulfonyl radicals with thiyl radical copper complex process to form
new sulfurꢀsulfone bonds in a highly selective manner. This method represents a useful contribution
to the area of radical crossꢀcoupling reaction.
EXPERIMENTAL SECTION
General Methods. 1H NMR (400 MHz) and 13C NMR (101 MHz) spectra were determined with
CDCl3 or DMSOꢀd6 as solvent and tetramethylsilane (TMS) as internal standard. Chemical shifts
were reported in ppm from internal TMS (δ), all coupling constants (J values) were reported in Hertz
(Hz). High resolution mass spectra were recorded on a TOF machine (ESI). Column chromatography
was performed with 300ꢀ400 mesh silica gel using flash column techniques. All of the reagents were
used directly as obtained commercially unless otherwise noted.
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General procedure for the preparation of thiosulfonates 3 and 4. To a acetonitrile (5 mL)
solution of sulfonylhydrazide 1 (1 mmol), thiol 2 (2 mmol) and CuBr2 (0.1 mmol) in Schlenk tube
equipped a magnetic bar was added tertꢀbutyl hydroperoxide (TBHP, 7.5 mmol) dropwise over a
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minute. The reaction mixture was stirred at 80 C for 2 hours in air. After the substrates were
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completely consumed, the solvent was evaporated off and the residue was purified by flash column
chromatography (silica gel, petroleum ether/EtOAc = 40:1) to afford the thiosulfonates 3 and 4.
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Sꢀphenylꢀ4ꢀmethylbenzenesulfonothioate (3a).7d Yellow solid, mp 73.5−74.8 C, 84% yield (216
1
mg). H NMR (400 MHz, CDCl3): δ 7.49 – 7.44 (m, 1H), 7.43 (d, J = 8.4 Hz, 2H), 7.37 – 7.30 (m,
4H), 7.19 (d, J = 10 Hz, 2H), 2.41 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 144.3, 139.7, 136.1,
130.9, 129.0, 128.9, 127.5, 127.1, 21.2. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C13H13O2S2
265.0357, found 265.0353.
Sꢀpꢀtolylꢀ4ꢀmethylbenzenesulfonothioate (3b). 7d Yellow solid, mp 76.7−77.5 oC, 86% yield (240
mg). 1H NMR (400 MHz, CDCl3): δ 7.46 (d, J = 8.3 Hz, 2H), 7.24 (d, J = 8.2 Hz, 2H), 7.21 (d, J =
13
8.1 Hz, 2H), 7.14 (d, J = 8.0 Hz, 2H), 2.42 (s, 3H), 2.38 (s, 3H); C NMR (100 MHz, CDCl3): δ
144.6, 142.0, 140.5, 136.5, 130.2, 129.4, 127.6, 124.6, 21.7, 21.5. HRMS (ESIꢀTOF) m/z: (M + H)+
Calcd for C14H15O2S2 279.0513, found 279.0504.
7d
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Sꢀoꢀtolylꢀ4ꢀmethylbenzenesulfonothioate (3c). Yellow solid, mp 104.1−104.6 C, 85% yield
(236 mg). 1H NMR (400 MHz, CDCl3): δ 7.44 (d, J = 8.3 Hz, 2H), 7.35 (dd, J = 13.1, 7.1 Hz, 2H),
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7.22 (t, J = 8.1 Hz, 3H), 7.16 (t, J = 7.6 Hz, 1H), 2.43 (s, 3H), 2.16 (s, 3H); C NMR (100 MHz,
CDCl3): δ 144.7, 144.2, 140.8, 138.3, 131.8, 131.0, 129.4, 127.5, 127.3, 126.9, 21.7, 20.7. HRMS
(ESIꢀTOF) m/z: (M + H)+ Calcd for C14H15O2S2 279.0513, found 279.0499.
Sꢀmꢀtolylꢀ4ꢀmethylbenzenesulfonothioate (3d). 7d Yellow solid, mp 76.5−77.0 oC, 83% yield (230
mg). 1H NMR (400 MHz, CDCl3): δ 7.46 (d, J = 8.3 Hz, 2H), 7.27 (d, J = 6.8 Hz, 1H), 7.23 – 7.19
(m, 3H), 7.17 (s, 1H), 7.13 (d, J = 7.5 Hz, 1H), 2.42 (s, 3H), 2.30 (s, 3H); 13C NMR (100 MHz,
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CDCl3): δ 144.1, 139.8, 138.9, 136.7, 133.0, 131.6, 128.8, 128.7, 127.2, 127.2, 21.2, 20.6. HRMS
(ESIꢀTOF) m/z: (M + H)+ Calcd for C14H15O2S2 279.0513, found 279.0525.
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Sꢀ(4ꢀmethoxyphenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3e).
White solid, mp 127.2−128.0 C,
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68% yield (199 mg). H NMR (400 MHz, CDCl3): δ 7.46 (d, J = 8.3 Hz, 2H), 7.27 (d, J = 8.2 Hz,
2H), 7.22 (d, J = 8.0 Hz, 2H), 6.84 (d, J = 8.9 Hz, 2H), 3.83 (s, 3H), 2.42 (s, 3H); 13C NMR (100
MHz, CDCl3): δ 161.8, 144.1, 139.9, 137.9, 128.9, 127.1, 118.3, 114.5, 55.0, 21.2. HRMS (ESIꢀTOF)
m/z: (M + H)+ Calcd for C14H15O3S2 295.0463, found 295.0477.
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Sꢀ(3ꢀmethoxyphenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3f). 7d White solid, mp 97.8−98.6 oC, 75%
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yield (220 mg). H NMR (400 MHz, CDCl3): δ 7.48 (d, J = 8.3 Hz, 2H), 7.23 (t, J = 8.1 Hz, 3H),
7.00 (ddd, J = 8.4, 2.6, 0.9 Hz, 1H), 6.93 (ddd, J = 7.6, 1.5, 1.0 Hz, 1H), 6.88 (dd, J = 2.4, 1.7 Hz,
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1H), 3.72 (s, 3H), 2.42 (s, 3H); C NMR (100 MHz, CDCl3): δ 159.3, 144.2, 139.8, 129.6, 128.9,
128.3, 128.3, 127.2, 120.3, 117.6, 54.9, 21.2. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C14H15O3S2
295.0463, found 295.0470.
7d
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Sꢀ(2ꢀmethoxyphenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3g).
White solid, mp 103.5−104.0 C,
74% yield (217 mg). 1H NMR (400 MHz, CDCl3): δ 7.57 – 7.47 (m, 3H), 7.47 – 7.42 (m, 1H), 7.21
(d, J = 8.1 Hz, 2H), 6.97 (td, J = 7.6, 1.1 Hz, 1H), 6.79 (d, J = 8.3 Hz, 1H), 3.48 (s, 3H), 2.42 (s, 3H);
13C NMR (100 MHz, CDCl3): δ 160.2, 144.2, 141.6, 139.5, 133.8, 129.1, 127.7, 121.3, 115.6, 113.1,
55.4, 21.6. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C14H15O3S2 295.0463, found 295.0475.
Sꢀ(4ꢀfluorophenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3h).8 Yellow solid, mp 92.8−93.5 C, 80%
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yield (226 mg). H NMR (400 MHz, CDCl3): δ 7.45 (d, J = 8.2 Hz, 2H), 7.35 (dd, J = 8.6, 5.3 Hz,
2H), 7.23 (d, J = 8.1 Hz, 2H), 7.03 (t, J = 8.5 Hz, 2H), 2.43 (s, 3H); 13C NMR (100 MHz, CDCl3): δ
164.3 (d, J = 253.7 Hz), 144.5, 139.6, 138.4 (d, J = 9.1 Hz), 129.0, 127.1, 123.1 (d, J = 3.3 Hz),
116.3 (d, J = 22.3 Hz), 21.2. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C13H12FO2S2 283.0263,
found 283.0257.
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Sꢀ(2ꢀfluorophenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3i).8 Yellow solid, mp 65.8−66.2 C, 77%
yield (221 mg). 1H NMR (400 MHz, CDCl3): δ 7.54 – 7.41 (m, 4H), 7.23 (d, J = 8.1 Hz, 2H), 7.18 (t,
J = 7.1 Hz, 1H), 7.06 (td, J = 8.7, 1.1 Hz, 1H), 2.43 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 162.4 (d,
J = 253.7 Hz), 144.5, 140.2, 138.6, 133.7 (d, J = 8.3 Hz), 129.0, 127.0, 124.5, 115.9 (d, J = 22.7 Hz),
114.9 (d, J = 17.8 Hz), 21.2. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C13H12FO2S2 283.0263,
found 283.0250.
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Sꢀ(4ꢀchlorophenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3j).7d Yellow solid, mp 86.1−87.2 C, 83%
yield (247 mg). 1H NMR (400 MHz, CDCl3): δ 7.47 (d, J = 8.3 Hz, 2H), 7.35 – 7.28 (m, 4H), 7.24 (d,
J = 8.2 Hz, 2H), 2.43 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 144.5, 139.7, 137.7, 137.2, 129.2,
129.1, 127.1, 126.1, 21.2. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C13H12ClO2S2 298.9967, found
298.9961.
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Sꢀ(3ꢀchlorophenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3k). Yellow solid, mp 77.6−78.5 C, 79%
yield (235 mg). 1H NMR (400 MHz, CDCl3): δ 7.47 (d, J = 8.4 Hz, 2H), 7.46 – 7.41 (m, 1H), 7.32 –
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7.27 (m, 3H), 7.25 (d, J = 8.1 Hz, 2H), 2.44 (s, 3H); C NMR (100 MHz, CDCl3): δ 145.2, 140.0,
136.1, 134.8, 134.6, 131.4, 130.4, 129.7, 129.5, 127.7, 21.7. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd
for C13H12ClO2S2 298.9967, found 298.9962.
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Sꢀ(2ꢀchlorophenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3l). White solid, mp 117.6−118.2 C, 80%
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yield (238 mg). H NMR (400 MHz, CDCl3): δ 7.68 (d, J = 8.2 Hz, 1H), 7.47 (d, J = 8.3 Hz, 2H),
7.43 – 7.37 (m, 2H), 7.34 – 7.29 (m, 1H), 7.22 (d, J = 8.1 Hz, 2H), 2.43 (s, 3H); 13C NMR (100 MHz,
CDCl3): δ 144.6, 140.3, 139.8, 139.1, 132.4, 129.8, 129.1, 127.2, 127.1, 126.7, 21.2.HRMS (ESIꢀ
TOF) m/z: (M + H)+ Calcd for C13H12ClO2S2 298.9967, found 298.9962.
Sꢀ(4ꢀbromophenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3m).7d Yellow solid, mp 102.5−103.4 C,
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83% yield (283 mg). H NMR (400 MHz, CDCl3): δ 7.49 (d, J = 2.7 Hz, 2H), 7.47 (d, J = 2.6 Hz,
13
2H), 7.26 – 7.21 (m, 4H), 2.43 (s, 3H); C NMR (100 MHz, CDCl3): δ 145.2, 140.0, 136.1, 134.6,
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131.4, 130.4, 129.5, 127.7, 21.7. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C13H12BrO2S2 342.9462,
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found 342.9453.
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Sꢀ(3ꢀbromophenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3n). Yellow solid, mp 73.9−74.8 C, 81%
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yield (277 mg). 1H NMR (400 MHz, CDCl3): δ 7.60 (ddd, J = 8.0, 1.9, 1.1 Hz, 1H), 7.47 (d, J = 8.4
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Hz, 2H), 7.41 – 7.35 (m, 2H), 7.26 – 7.18 (m, 3H), 2.44 (s, 3H); C NMR (100 MHz, CDCl3): δ
145.2, 139.9, 138.9, 135.1, 134.3, 130.7, 130.0, 129.5, 127.7, 122.6, 21.7. HRMS (ESIꢀTOF) m/z:
(M + H)+ Calcd for C13H12BrO2S2 342.9462, found 342.9464.
Sꢀ(4ꢀnitrophenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3o).7d Yellow solid, mp 129.9−130.2 oC, 62%
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yield (192 mg). H NMR (400 MHz, CDCl3): δ 8.18 (d, J = 8.9 Hz, 2H), 7.59 (d, J = 8.9 Hz, 2H),
7.49 (d, J = 8.4 Hz, 2H), 7.25 (d, J = 6.6 Hz, 2H), 2.44 (s, 3H); 13C NMR (100 MHz, CDCl3): δ
145.6, 140.2, 137.1, 135.8, 129.8, 127.6, 126.4, 124.1, 21.7. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd
for C13H12NO4S2 310.0208, found 310.0200.
Sꢀ(2,6ꢀdimethylphenyl)ꢀ4ꢀmethylbenzenesulfonothioate (3p). White solid; mp 95.3−95.7 oC, 91%
yield (266 mg). 1H NMR (400 MHz, CDCl3): δ 7.48 (d, J = 8.3 Hz, 2H), 7.26 – 7.21 (m, 3H), 7.10 (d,
J = 7.5 Hz, 2H), 2.44 (s, 3H), 2.20 (s, 6H); 13C NMR (100 MHz, CDCl3): δ 145.1, 144.3, 141.1,
131.0, 129.2, 128.3, 126.9, 126.40, 21.2, 21.2. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for
C15H17O2S2 293.0670, found 293.0656.
Sꢀthiophenꢀ2ꢀylꢀ4ꢀmethylbenzenesulfonothioate (3q). Purple solid, mp 51.8−52.0 oC, 52% yield
1
(140 mg). H NMR (400 MHz, CDCl3): δ 7.61 (dd, J = 5.3, 1.3 Hz, 1H), 7.54 (d, J = 8.4 Hz, 2H),
7.25 (d, J = 7.9 Hz, 2H), 7.16 (dd, J = 3.7, 1.3 Hz, 1H), 7.07 (dd, J = 5.3, 3.7 Hz, 1H), 2.44 (s, 3H);
13C NMR (100 MHz, CDCl3): δ 144.6, 139.0, 138.9, 134.6, 129.0, 127.9, 127.4, 124.9, 21.2. HRMS
(ESIꢀTOF) m/z: (M + H)+ Calcd for C11H11O2S3 270.9921, found 270.9927.
Sꢀpyridinꢀ2ꢀylꢀ4ꢀmethylbenzenesulfonothioate (3r).9 Yellow solid, mp 51.1−52.0 oC, 35% yield
(93 mg). 1H NMR (400 MHz, CDCl3): δ 8.52 (d, J = 4.5 Hz, 1H), 7.80 – 7.70 (m, 2H), 7.57 (d, J =
8.4 Hz, 2H), 7.38 – 7.32 (m, 1H), 7.24 (d, J = 8.1 Hz, 2H), 2.41 (s, 3H); 13C NMR (100 MHz,
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CDCl3): δ 150.7, 150.2, 144.5, 140.9, 137.3, 131.4, 129.1, 127.0, 124.4, 21.2. HRMS (ESIꢀTOF) m/z:
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(M + H)+ Calcd for C12H12NO2S2 266.0309, found 266.0315.
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Sꢀpꢀmethoxybenzylꢀ4ꢀmethylbenzenesulfonothioate (3s).10 White solid, mp 61.8−62.7 C, 70%
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yield (216 mg). H NMR (400 MHz, CDCl3): δ 7.74 (d, J = 8.3 Hz, 2H), 7.28 (d, J = 8.1 Hz, 2H),
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7.10 (d, J = 8.7 Hz, 2H), 6.75 (d, J = 8.7 Hz, 2H), 4.21 (s, 2H), 3.76 (s, 3H), 2.46 (s, 3H); 13C NMR
(100 MHz, CDCl3): δ 158.9, 144.1, 141.6, 129.9, 129.2, 128.5, 124.9, 113.7, 54.8, 39.4, 20.9. HRMS
(ESIꢀTOF) m/z: (M + Na)+ Calcd for C15H16O3S2Na 331.0439, found 331.0440.
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Sꢀpentylꢀ4ꢀmethylbenzenesulfonothioate (3t).11 Yellow liquid, 65% yield (168 mg). H NMR
(400 MHz, CDCl3): δ 7.81 (d, J = 8.4 Hz, 2H), 7.34 (d, J = 8.0 Hz, 2H), 3.04 – 2.92 (m, 2H), 2.45 (s,
3H), 1.58 – 1.56 (m, 2H), 1.29 – 1.24 (m, 4H), 0.84 (t, J = 7.1 Hz, 3H); 13C NMR (100 MHz,
CDCl3): δ 144.6, 142.1, 129.8, 127.0, 36.0, 30.7, 28.3, 22.0, 21.6, 13.8. HRMS (ESIꢀTOF) m/z: (M +
H)+ Calcd for C12H19O2S2 259.0826, found 259.0835.
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Sꢀdecylꢀ4ꢀmethylbenzenesulfonothioate (3u). Yellow liquid, 62% yield (204 mg). H NMR (400
MHz, CDCl3) : δ 7.81 (d, J = 5.0 Hz, 2H), 7.34 (d, J = 8.0 Hz, 2H), 2.98 (t, J = 8.0 Hz, 2H), 2.45 (s,
13
3H), 1.58 (t, J = 7.4 Hz, 2H), 1.26 – 1.17 (m, 12H), 0.88 (t, J = 6.9 Hz, 5H); C NMR (100 MHz,
CDCl3): δ 144.6, 142.2, 129.8, 127.0, 36.0, 31.9, 29.5, 29.34, 29.26, 28.9, 28.6, 28.5, 22.7, 21.6, 14.1.
HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C17H29O2S2 329.1609, found 329.1619.
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Sꢀphenyl benzenesulfonothioate (4a).7d Yellow liquid, 82% yield (206 mg). H NMR (400 MHz,
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CDCl3): δ 7.60 – 7.54 (m, 3H), 7.49 – 7.45 (m, 1H), 7.45 – 7.39 (m, 2H), 7.38 – 7.31 (m, 4H); C
NMR (100 MHz, CDCl3): δ 142.5, 136.1, 133.1, 130.9, 129.0, 128.3, 127.4, 127.1. HRMS (ESIꢀ
TOF) m/z: (M + H)+ Calcd for C12H11O2S2 251.0200, found 251.0209.
Sꢀphenylꢀ3ꢀmethylbenzenesulfonothioate (4b). Yellow liquid, 82% yield (217 mg). 1H NMR (400
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MHz, CDCl3): δ 7.55 – 7.50 (m, 1H), 7.45 – 7.37 (m, 7H), 7.36 – 7.32 (m, 1H), 2.38 (s, 3H); C
NMR (100 MHz, CDCl3): δ 142.3, 138.6, 136.2, 133.9, 130.9, 128.9, 128.1, 127.5, 127.4, 124.2,
20.7. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C13H13O2S2 265.0357, found 265.0354.
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Sꢀphenylꢀ2ꢀmethylbenzenesulfonothioate (4c).8 Yellow liquid, 82% yield (217 mg). H NMR
(400 MHz, CDCl3): δ 7.49 – 7.43 (m, 2H), 7.40 (dd, J = 8.0, 1.0 Hz, 1H), 7.35 (d, J = 7.5 Hz, 1H),
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7.33 – 7.26 (m, 4H), 7.11 (t, J = 7.7 Hz, 1H), 2.72 (s, 3H); C NMR (100 MHz, CDCl3): δ 139.8,
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137.4, 136.1, 133.4, 132.4, 130.8, 129.7, 128.8, 127.3, 125.2, 20.0. HRMS (ESIꢀTOF) m/z: (M + H)+
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Calcd for C13H13O2S2 265.0357, found 265.0363.
Sꢀphenylꢀ4ꢀmethoxybenzenesulfonothioate (4d).8 Yellow liquid, 88% yield (246 mg). H NMR
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(400 MHz, CDCl3): δ 7.51 – 7.41 (m, 3H), 7.40 – 7.27 (m, 4H), 6.85 (d, J = 9.0 Hz, 2H), 3.85 (s,
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3H); C NMR (101 MHz, CDCl3): δ 163.1, 136.1, 134.4, 130.8, 129.4, 128.9, 127.7, 113.4, 55.3.
HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C13H13O3S2 281.0306, found 281.0317.
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Sꢀphenylꢀ3ꢀmethoxybenzenesulfonothioate (4e). Yellow liquid, 83% yield (232 mg). H NMR
(400 MHz, CDCl3): δ 7.46 – 7.42 (m, 1H), 7.37 – 7.27 (m, 5H), 7.12 (d, J = 7.7 Hz, 1H), 7.06 (d, J =
13
8.2 Hz, 1H), 6.95 (s, 1H), 3.66 (s, 3H); C NMR (100 MHz, CDCl3): δ 159.0, 143.4, 136.2, 131.0,
129.3, 129.0, 127.5, 120.2, 119.2, 111.1, 55.1. HRMS (ESIꢀTOF) m/z: (M + Na)+ Calcd for
C13H12O3S2 Na 303.0126, found 303.0106.
Sꢀphenylꢀ4ꢀfluorobenzenesulfonothioate (4f).8 Yellow liquid, 81% yield (217 mg). 1H NMR (400
MHz, CDCl3): δ 7.56 (dd, J = 8.9, 5.0 Hz, 2H), 7.52 – 7.45 (m, 1H), 7.40 – 7.31 (m, 4H), 7.08 (t, J =
13
8.5 Hz, 2H); C NMR (100 MHz, CDCl3): δ 165.0 (d, J = 256.9 Hz), 138.5 (d, J = 3.1 Hz), 136.1,
131.1, 130.0 (d, J = 9.7 Hz), 129.1, 127.2, 115.6 (d, J = 22.8 Hz). HRMS (ESIꢀTOF) m/z: (M+H)+
Calcd for C12H10FO2S2 269.0106, found 269.0116.
Sꢀphenylꢀ4ꢀchlorobenzenesulfonothioate (4g).8 Yellow solid, mp 80.7−81.3 oC, 82% yield (233
mg). 1H NMR (400 MHz, CDCl3): δ 7.54 – 7.47 (m, 3H), 7.43 – 7.35 (m, 6H); 13C NMR (100 MHz,
CDCl3): δ 140.9, 139.8, 136.1, 131.2, 129.1, 128.6, 128.5, 127.1. HRMS (ESIꢀTOF) m/z: (M + H)+
Calcd for C12H10ClO2S2 284.9811, found 284.9803.
Sꢀphenylꢀ3ꢀchlorobenzenesulfonothioate (4h). Yellow solid, mp 65.2−62.8 oC, 80% yield (227
1
mg). H NMR (400 MHz, CDCl3): δ 7.59 – 7.49 (m, 3H), 7.46 (d, J = 8.0 Hz, 1H), 7.42 – 7.36 (m,
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5H); C NMR (100 MHz, CDCl3): δ 143.7, 136.1, 134.6, 133.2, 131.3, 129.6, 129.1, 127.2, 126.9,
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125.1. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C12H10ClO2S2 284.9811, found 284.9801.
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Sꢀphenylꢀ2ꢀchlorobenzenesulfonothioate (4i). Yellow solid, mp 84.0−84.6 C, 79% yield (224
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mg). H NMR (400 MHz, CDCl3): δ 7.59 (d, J = 7.9 Hz, 1H), 7.54 – 7.47 (m, 2H), 7.43 (t, J = 7.2
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Hz, 1H), 7.37 – 7.32 (m, 2H), 7.32 – 7.27 (m, 2H), 7.20 (td, J = 7.8, 1.2 Hz, 1H); C NMR (100
MHz, CDCl3): δ 138.7, 136.1, 134.1, 132.2, 131.9, 131.12, 131.07, 128.9, 127.0, 126.0. HRMS
(ESIꢀTOF) m/z: (M + H)+ Calcd for C12H10ClO2S2 284.9811, found 284.9801.
Sꢀphenylꢀ4ꢀbromobenzenesulfonothioate (4j).8 Yellow solid, mp 76.2−76.8 oC, 78% yield (256
mg). 1H NMR (400 MHz, CDCl3): δ 7.60 (d, J = 8.7 Hz, 2H), 7.57 – 7.52 (m, 1H), 7.45 (d, J = 8.7
Hz, 2H), 7.43 – 7.36 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 141.4, 136.1, 131.6, 131.2, 129.1,
128.5, 128.4, 127.0. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C12H10BrO2S2 328.9306, found
328.9298.
Sꢀphenylꢀ2ꢀbromobenzenesulfonothioate (4k). Yellow solid, mp 57.3−58.0 oC, 77% yield (254
1
mg). H NMR (400 MHz, CDCl3): δ 7.81 (dd, J = 7.9, 1.0 Hz, 1H), 7.54 (dd, J = 8.0, 1.6 Hz, 1H),
7.46 – 7.37 (m, 2H), 7.36 – 7.21 (m, 5H); 13C NMR (100 MHz, CDCl3): δ 140.2, 136.2, 135.4, 133.9,
131.4, 131.0, 128.9, 127.1, 126.6, 120.3. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C12H10BrO2S2
328.9306, found 328.9302.
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Sꢀphenylꢀ4ꢀacetylbenzenesulfonothioate (4l). Yellow liquid, 74% yield (216 mg). H NMR (400
MHz, CDCl3): δ 8.02 (d, J = 8.6 Hz, 2H), 7.69 (d, J = 8.6 Hz, 2H), 7.57 – 7.53 (m, 1H), 7.43 – 7.39
(m, 4H), 2.69 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 196.2, 145.9, 140.0, 136.1, 131.2, 129.2,
128.2, 127.3, 126.9, 26.4. HRMS (ESIꢀTOF) m/z: (M + H)+ Calcd for C14H13O3S2 293.0306, found
293.0316.
Sꢀphenylꢀ4ꢀcyanobenzenesulfonothioate (4m). White solid, mp 141.2−142.4 oC, 75% yield (207
mg). 1H NMR (400 MHz, CDCl3): δ 7.72 (d, J = 8.2 Hz, 2H), 7.65 (d, J = 8.1 Hz, 2H), 7.55 – 7.49
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(m, 1H), 7.45 – 7.30 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 146.0, 136.0, 132.2, 131.5, 129.3,
127.6, 126.5, 116.8, 116.6. HRMS (ESIꢀTOF) m/z: (M + Na)+ Calcd for C13H9NO2S2Na 297.9972,
found 297.9956.
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Sꢀphenylꢀ2ꢀnitrobenzenesulfonothioate (4n).12 Yellow liquid, 62% yield (183 mg). 1H NMR (400
MHz, CDCl3): δ 8.26 (d, J = 8.9 Hz, 2H), 7.73 (d, J = 11.2 Hz, 2H), 7.55 – 7.51 (m, 1H), 7.43 – 7.36
(m, 4H); 13C NMR (101 MHz, CDCl3): δ 149.9, 147.4, 136.0, 131.6, 129.4, 128.3, 126.4, 123.6.
HRMS (ESIꢀTOF) m/z: (M + Na)+ Calcd for C12H9NO4S2Na 317.9871, found 317.9892.
1ꢀPhenylꢀ2ꢀtosylethanone (6b). White solid, 1H NMR (400 MHz, CDCl3): δ 7.88 (d, J = 7.6 Hz,
2H), 7.70 (d, J = 8.1 Hz, 2H), 7.55 (t, J = 7.4 Hz, 1H), 7.42 (t, J = 7.7 Hz, 2H), 7.27 (d, J = 8.1 Hz,
2H), 4.65 (s, 2H), 2.38 (s, 3H); 13C NMR (101 MHz, CDCl3): δ 187.09, 144.32, 134.66, 133.26,
128.77, 128.74, 128.26, 128.24, 127.77, 127.74, 127.54, 127.51, 62.5, 20.6. HRMS (ESIꢀTOF) m/z:
(M + Na)+ Calcd for C15H14O3SNa 297.0561, found 297.0558.
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ASSOCIATED CONTENT
Supporting Information
1H, and 13C NMR spectra for compounds 3, 4 and 6b. This material is available free of charge via the
Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
*Eꢀmail: jpzou@suda.edu.cn.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGEMENTS
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J.ꢀP.Z. specially thank the National Natural Science Foundation of China (Nos. 20772088,
21172163, 21472133), the Priority Academic Program Development of Jiangsu Higher Education
Institutions & State and Local Joint Engineering Laboratory for Novel Functional Polymeric
Materials for their financial support.
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REFERENCES
(1) Selected reviews on the oxidative radical crossꢀcoupling reactions, see: (a) Togo, H. In Advanced Free
Radical Reactions for Organic Synthesis; Elsevier Science: Amsterdam. 2004. (b) Staveness, D.; Bosque,
I.; Stephenson, C. R. Acc. Chem. Res. 2016, 49, 2295. (c) Studer, A.; Curran, D. P. Angew. Chem. Int. Ed.
2016, 55, 58. (d) Yan, M.; Lo, J. C.; Edwards, J. T.; Baran, P. S. J. Am. Chem. Soc. 2016, 138, 12692. (e)
Liu, C.; Liu, D.; Lei, A. Acc. Chem. Res. 2014, 47, 3459. (f) Liu, Q.; Jackstell, R.; Beller, M. Angew.
Chem. Int. Ed. 2013, 52, 13871. (g) Curran, D. P. Aldrichimica Acta. 2000, 33, 104.
(2) Selected recent papers on the radicalꢀradical crossꢀcoupling reactions, see: (a) Liu, Z. J.; Lu, X.; Wang,
G.; Li, L.; Jiang, W. T.; Wang, Y. D.; Xiao, B.; Fu, Y. J. Am. Chem. Soc. 2016, 138, 9714. (b) Miller, D.
C.; Choi, G. J.; Orbe, H. S.; Knowles, R. R. J. Am. Chem. Soc. 2015, 137, 13492 and references cited
therein. (c) Jeffrey, J.; Petronijevic, F. R.; MacMillan, D. W. C. J. Am. Chem. Soc. 2015, 137, 8404 and
references cited therein. (d) Zhou, L.; Tang, S.; Qi, X.; Lin, C.; Liu, K.; Liu, C.; Lan, Y.; Lei, A. Org.
Lett. 2014, 16, 3404 and references cited therein. (e) Lu, Q.; Zhang, J.; Zhao, G.; Qi, Y.; Wang, H.; Lei,
A. J. Am. Chem. Soc. 2013, 135, 11481 and references cited therein.
(3) Chatgilialoglu, C.; Studer, A. Encyclopedia of Radicals in Chemistry, Biology and Materials, Vol. 1–4,
Wiley, Chichester, UK, 2012.
(4) (a) Studer, A. Chem. Eur. J. 2001, 7, 1159. (b) Fischer, H. Chem. Rev. 2001, 101, 3581. (c) Focsaneanu,
K. S.; Scaiano, J. C. Helv. Chim. Acta. 2006, 89, 2473. (d) Keshari, T.; Kapoorr, R.; Yadav, L. D. S.
Synlett 2016, 27, 1878.
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(5) (a) Yang, F. L.; Tian, S. K. Tetrahedron Lett. 2017, 58, 487. (b) Du, B. N.; Li, Z.; Qian, P.; Han, J. L.;
Pan, Y. Chem. Asian J. 2016, 11, 478 and references cited therein. (c) Tang, S.; Wu, Y.; Liao, W. Q.;
Bai, R. P.; Liu, C.; Lei, A. W. Chem. Commun. 2014, 50, 4496. (d) Li, X. W.; Xu, Y. L.; Wu, W. Q.;
Jiang, C.; Qi, C. R.; Jiang, H. F. Chem. Eur. J. 2014, 20, 7911.
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(6) (a) Zhou, S. F.; Pan, X. Q.; Zhou, Z. H.; Shoberu, A.; Zou, J. P. J. Org. Chem. 2015, 80, 3682. (b) Zhou,
S. F.; Pan, X. Q.; Zhou, Z. H.; Shoberu, A.; Zhang, P. Z.; Zou, J. P. J. Org. Chem. 2015, 80, 5348. (c)
Yi, C.ꢀL.; Huang, Y.ꢀT.; Lee, C.ꢀF. Green Chem., 2013, 15, 2476. (d) Zeng, J.ꢀW.; Liu, Y.ꢀC.; Hsieh, P.ꢀ
A.; Huang, Y.ꢀT.; Yi, C.ꢀL.; Badsara, S. S.; Lee, C.ꢀF. Green Chem., 2014, 16, 2644. (e) Huang, Y.ꢀT.;
Lu, S.ꢀY.; Yi, C.ꢀL.; Lee, C.ꢀF. J. Org. Chem. 2014, 79, 4561.
(7) (a) Steudel, R. Chem. Rev. 2002, 102, 3905. (b) Xu, X. H.; Matsuzaki, K.; Shibata, N. Chem. Rev. 2015,
115, 731. (c) Taniguchi, N. Eur. J. Org. Chem. 2014, 5691. (d) Taniguchi, N. J. Org. Chem. 2015, 80,
1764. (e) Shyam, P. K.; Kim, Y. K.; Lee, C.; Jang, H. Y. Adv. Synth. Catal. 2016, 358, 56.
(8) Liang, G. G.; Wu, H. Y. Chin. J. Chem., 2012, 30, 1611.
(9) Barton, D. H. R.; Ramesh, M. Tetrahedron Lett. 1990, 31, 949.
(10)
Kimura, S.; Eckhard, B.; Eberhard, B.; Weyhermu1ller, T.; Wieghardt, K. J. Am. Chem. Soc., 2001,
123, 6025.
(11)
(12)
Sato, T. Jpn. Kokai Tokkyo Koho, 2008, 280297.
Boldyrev, B. G.; Bilozor, T. K. Zhur. Organich. Khim, 1987, 23, 1878.
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