Synthesis of N -Arylsulfonamides by a Copper-Catalyzed Reaction of Chloramine-T and Arylboronic Acids at Room Temperature

Article abstract of DOI:10.1055/s-0036-1590978

A copper-catalyzed Chan-Lam-coupling-like reaction of a (het)arylboronic acid and chloramine-T (or a related compound) has been developed for the synthesis of N -arylsulfonamides at room temperature in moderate to good yields, with good tolerance of functional groups. In this process, it is believed that chloramine-T serves as an electrophile.

Full text of DOI:10.1055/s-0036-1590978

SYNLETT
0
9
3
6
-
5
2
1
4
1
4
3
7
-
2
0
9
6
© Georg Thieme Verlag Stuttgart · New York
2017, 28, A–E
letter
A
en
B. Ouyang et al.
Letter
Synlett
Synthesis of N-Arylsulfonamides by a Copper-Catalyzed Reaction
of Chloramine-T and Arylboronic Acids at Room Temperature
Banlai Ouyang*a
Cu(OAc)2 (5 mol%)
Deming Liua
Kejian Xiaa
Yanxia Zhenga
Hongxin Meia
Guanyinsheng Qiu*b
O
S
O
O
tBuOK
Cl
(Het)Ar-B(OH)2
S
Ar(Het)
Ar'
N
+
Ar'
N
H
Na
O
EtOH, Air, RT
29 examples
up to 73% yield
no ligand
open flask
room temperature
a Department of Chemistry, Nanchang Normal University,
889 Ruixiang Road, Nanchang 330032, P. R. of China
nsouyang@outlook.com
b College of Biological, Chemical Science and Engineering,
Jiaxing University, 118 Jiahang Road, Jiaxing 314001,
P. R. of China
11110220028@fudan.edu.cn
Received: 14.06.2017
Accepted after revision: 04.08.2017
Published online: 29.08.2017
atom is removed in the form of BrCl.7 Theoretically, chlora-
mine-T can also serve as an electrophile, because it readily
undergoes oxidative addition at the N–Cl bond in the pres-
ence of an appropriate metal catalyst.8 As such, we were in-
terested in exploring this electrophilic reactivity of chlora-
mine-T for the synthesis of pharmaceutically interesting
motifs.
DOI: 10.1055/s-0036-1590978; Art ID: st-2017-w0473-l
Abstract A copper-catalyzed Chan–Lam-coupling-like reaction of a
(het)arylboronic acid and chloramine-T (or a related compound) has
been developed for the synthesis of N-arylsulfonamides at room tem-
perature in moderate to good yields, with good tolerance of functional
groups. In this process, it is believed that chloramine-T serves as an
electrophile.
A) The Previous Works:
Na
X
R1
R2
R3
R1
R2
R3
R4
Haloamidation
X = Cl, Br
Key words chloramine-T, cross-coupling, copper catalysis, arylboron-
ic acids, arylsulfonamides
N
N
Ts
Ts
TsHN
X
R4
(a)
(b)
+
+
Na
X
R1
R3
R1
R2
R3
R4
Aminohydroxylation
Chloramine-T {sodium chloro[(4-methyl phenyl)sulfo-
nyl]azanide} is recognized as an important source of N-
building blocks (especially of nitrenes), because of its ready
commercial availability.1 Chlorosulfamidation, aminohy-
droxylation, or aziridination of olefins and sulfamidation of
relatively highly reactive alkanes can be performed by using
chloroamine-T with or without metal catalysis to give chlo-
rosulfamidated products [Scheme 1, a],2 N-protected β-
amino alcohols [Scheme 1, b],3 aziridines [Scheme 1, c],4 or
sulfamidated compounds [Scheme 1, d],5 respectively. In
these procedures, nitrene species derived from chloramine-
T by metal- or nonmetal-assisted removal of sodium chlo-
ride are generally regarded as intermediates. In 1998, Smith
and co-workers discovered that chloramine-T reacts with
alkylboranes in the absence of a catalyst to give N-alkylsul-
fonamides.6 Recently, Chandrasekaran and co-workers
found that chloramine-T behaves as an efficient dual nucle-
ophile when vinylcyclopropanes are used as reaction part-
ners in the presence of bromine, leading to [4.4.0] and
[4.3.0] bicyclic amidines through tandem ring opening of
the vinylcyclopropane and double-nucleophilic addition of
chloramine-T; their results also showed that chloramine-T
can be regarded as a dual nucleophile when its chlorine
TsHN
OH
R4
R2
R1
R2
R3
R4
R1
R2
R3
R4
Aziridination
X = Cl, Br
Na
X
N
N
Ts
Ts
(c)
(d)
+
+
N
Ts
R1
R2
R3
R1
R2
Na
X
Sulfamidation
X = Cl, Br
H
NHTs
R3
B) This Work:
Na
[Cu]
Ar B(OH)2
Ar NHTs
N
Ts
+
Cl
This Work
Scheme 1 Chloramine-T-based C–N bond-formation reactions
The N-arylsulfonamide group is an important moiety in
medicinal chemistry because of its presence in many useful
molecules with potential bioactivities.9 Consequently, tre-
mendous efforts have been made to develop methods for its
synthesis. N-Arylsulfonamides are normally prepared by
nucleophilic substitution of a sulfonyl chloride with an aro-
matic amine. Although effective, this classical approach re-
© Georg Thieme Verlag Stuttgart · New York — Synlett 2017, 28, A–E

B
B. Ouyang et al.
Letter
Synlett
quires the use of mutagenic sulfonyl chlorides and genotox-
ic aryl amines. Alternatively, the metal-catalyzed cross-cou-
pling of sulfonamides with aromatic halides or other
analogous compounds permits the synthesis of N-arylsul-
fonamide without the use of sulfonyl chloride, but these re-
actions are generally require harsh conditions because of
the low nucleophilicity of sulfonamides.10 In 1998, Chan
and co-workers reported a synthesis of N-arylsulfonamides
from sulfonamides and arylboronic acids.11 This C–N bond-
formation reaction can be performed under mild condi-
tions; however, it suffers from the drawback of requiring
the use of a stoichiometric amount of Cu(OAc)2. Since this
reaction was first reported, many modifications have been
demonstrated. For instance, Lam et al. developed several
catalytic copper/oxidant systems to carry out the N-aryla-
tion of NH-containing substrates.12 Although catalytic,
those conditions work only for a limited range of sulfon-
amides. In 2014, Nasrollahzadeh and co-workers developed
a simple Cu(OAc)2-catalyzed arylation of sulfonamides in
water under ligand-free conditions, but this transformation
requires elevated temperatures and is incompatible with
ortho-substituted arylboronic acids.13 Another elegant ex-
ample, developed by Kim and co-workers, involved a cop-
per-catalyzed Chan–Lam cross-coupling between an aryl-
boronic acid and a sulfonyl azide to give various N-arylsul-
fonamides.14 However, in general, sulfonyl azides are not
shelf-stable and they require precautions in handling.
Therefore, it is desirable to develop more-efficient and
more-convenient methods for the synthesis of N-arylsul-
fonamides.
Inspired by the methods described above, we decided to
examine the preparation of N-arylsulfonamides from chlo-
ramine-T. Initially, we examined the reaction of 4-tolylbo-
ronic acid (1k) with chloramine-T (2a) as a model reaction
for the optimization of the conditions. To our delight, the
desired 4-methyl-N-(4-tolyl)benzenesulfonamide (3k) was
obtained in the presence of 5 mol% of Cu(OAc)2 and 1.0
equivalent of NaOH in MeOH as a solvent at 60 °C (Table 1,
entry 1). Encouraged by this positive result, we examined
various other factors (Table 1). From a screening of bases, it
emerged that potassium tert-butoxide was the optimal
choice, providing the desired N-arylsulfonamide 3k in 42%
isolated yield (Table 1, entry 4); other bases (triethylamine,
potassium hydroxide, and DBU) gave inferior yields (Table
1, entries 2, 3, and 5). Subsequently, various copper sources
were also examined and copper (II) catalysts were found to
be more efficient than copper (I) catalysts for the formation
of 3a, and no better copper source than Cu(OAc)2 was found
(Table 1, entries 6–11). We also examined the effect of the
solvent, and found that protic solvents such as ethanol, iso-
propyl alcohol, and tert-butanol tended to give better re-
sults than did aprotic solvents such as methyl tert-butyl
ether, tetrahydrofuran, 1,2-dichloroethane, or acetonitrile
(Table 1, entries 12–18). Among the protic solvents, ethanol
gave the best yield (54%) of the N-arylsulfonamide 3a (Table
1, entry 12). A subsequent evaluation of the effect of the
temperature showed that reducing the reaction tempera-
ture to room temperature had no significant effect on the
yield (Table 1, entry 19). The yield increased slightly when
the reaction time was prolonged to 12 hours (Table 1, entry
20). A further increase in the reaction time or an increased
loading of the arylboronic acid did not improve the yield
(Table 1, entries 21 and 22, respectively). Interestingly,
when the amount of the potassium tert-butoxide base was
Table 1 Initial Studies on the Copper-Prompted Reaction of Aryl-
boronic Acid 1k with Chloramine-T 2aa
NHTs
Na
Cl
[Cu]/Base
B(OH)2
N
Ts
+
Solvent, Temp., Air
1k
2a
3k
Entry Catalyst
Base
Solvent
Temp (°C) Yieldb (%)
1
2
Cu(OAc)2
NaOH
MeOH
MeOH
MeOH
MeOH
MeOH
MeOH
MeOH
MeOH
MeOH
MeOH
MeOH
EtOH
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
60
25
25
25
25
25
25
24
19
22
42
18
21
17
29
26
33
37
54
49
40
24
trace
39
20
50
52
46
51
60
55
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
CuCl2
Et3N
3
KOH
4
t-BuOK
DBU
5
6
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
t-BuOK
7
CuCl
8
CuBr2
9
CuBr
10
11
12
13
14
15
16
17
18
19
20c
21d
22e
23f
24g
CuI
Cu(OTf)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
Cu(OAc)2
i-PrOH
t-BuOH
t-BuOMe
THF
DCE
MeCN
EtOH
EtOH
EtOH
EtOH
EtOH
EtOH
a Reagents and conditions: chloramine-T (0.3 mmol ), 4-TolB(OH)2
(1.2 equiv), base (1.0 equiv), catalyst (0.05 equiv), solvent (1.5 mL), 6 h.
b Isolated yield.
c Reaction time 12 h.
d Reaction time 24 h.
e 4-TolB(OH)2 (2.0 equiv).
f t-BuOK (1.5 equiv).
g t-BuOK (2.0 equiv).
© Georg Thieme Verlag Stuttgart · New York — Synlett 2017, 28, A–E

C
B. Ouyang et al.
Letter
Synlett
increased to 1.5 equivalents, the yield improved to 60% (Ta-
ble 1, entry 23). A further increase in the amount of base
did not produce any improvement (Table 1, entry 24).
the desired N-arylsulfonamide 3h was obtained in 53% iso-
lated yield.
Arylboronic acids with electron-donating substituents
on the aryl moiety also reacted efficiently with chloramine-
T (2a), giving the corresponding N-arylsulfonamide 3k–p.
For example, the reaction of 3-tolylboronic acid (1, R1 = 3-
Me) and (2-methoxyphenyl)boronic acid (1, R1 = 2-OMe)
gave the N-arylsulfonamides 3l and 3o in 72 and 73% yield,
respectively. 1-Naphthylboronic acid and 2-naphthylboron-
ic acid were also suitable reactants, providing the corre-
sponding N-arylsulfonamides 3r and 3s in 49 and 69%
yields, respectively. However, 1,3-benzodioxol-5-ylboronic
acid was a less efficient reactant in the synthesis of the N-
arylsulfonamide 3q (37% yield), probably due to its high re-
ducibility and reactivity for homocoupling. Additionally,
hetarylboronic acids were good reaction partners for the
formation of corresponding N-hetarylsulfonamides. For in-
stance, the reaction of [6-(dimethylamino)pyridin-3-yl]bo-
ronic acid gave the desired N-pyridinylsulfonamide 3t in
43% yield.
With the optimized conditions in hand [Cu(OAc)2 (5
mol%) and t-BuOK (1.5 equiv) in EtOH at room tempera-
ture], we examined the scope and generality of the reaction
of various arylboronic acids 1 with chloramine-T (2a)
(Scheme 2), and obtained the expected series of N-arylsul-
fonamides 3. To our delight, arylboronic acids with elec-
tron-withdrawing substituents, such as fluoro or trifluoro-
methyl groups, were compatible for the reaction, and gave
the corresponding N-arylsulfonamides 3b–j in moderate
yields. For example, the reaction of [4-(trifluorometh-
yl)phenyl]boronic acid and chloramine-T (2a) gave the N-
arylsulfonamide 3e in 51% yield. Moreover, a bromo substit-
uent survived the reaction; the reaction of (4-bromophe-
nyl)boronic acid (1, R1 = 4-Br) or (2-bromophenyl)boronic
acid (1, R1 = 2-Br) with chloramine-T (2a) gave N-arylsul-
fonamides 3i and 3j efficiently in 67 and 53% yield, respec-
tively, under the standard conditions. Furthermore, when
(3,5-dichlorophenyl)boronic acid was used as a substrate,
R2
Cu(OAc)2 (0.05 equiv)
tBuOK (1.5 equiv)
H
B(OH)2
O
S
N
Cl
S
R1
R2
R1
+
N
O
O
EtOH, RT, Air
Na
O
2a, R2 = Me;
2b, R2 = Cl
1
3 or 4
3a, R = H, 62%;
NHTs
3b, R = 4-F, 63%;
3c, R = 3-F, 55%;
3d, R = 2-F, 45%;
3e, R = 4-CF3, 51%;
3f, R = 4-Cl, 65%;
3g, R = 3-Cl, 57%;
3h, R = 3,5-Cl, 53%;
3i, R = 4-Br, 67%;
3j, R = 2-Br, 53%;
R
3k, R = 4-Me, 60%;
3l, R = 3-Me, 72%;
3m, R = 2-Me, 48%;
3n, R = 4-OMe, 47%;
3o, R = 2-OMe, 73%;
NHTs
R
3p, R = 4-NHCbz, 60%;
NHTs
O
O
NHTs
NHTs
3q, 37%
NHTs
3r, 49%
3s, 69%
Me2N
N
Cl
3t, 43%
H
N
S
R
O
O
Cl
4a, R = H, 45%;
H
N
S
4b, R = 4-Me, 62%;
4c, R = 3-Me, 69%;
4d, R = 2-OMe, 71%;
4e, R = 4-F, 50%;
4f, R = 3-F, 56%;
4g, R = 4-Cl, 42%;
4h, R = 4-Br, 43%
O
O
4i, 57%
Scheme 2 Synthesis of N-arylsulfonamides by the copper-induced reaction of arylboronic acids and sodium chloro(arylsulfonyl)azanides. Isolated yield
based on the chloramine compound 2 are reported.
© Georg Thieme Verlag Stuttgart · New York — Synlett 2017, 28, A–E

D
B. Ouyang et al.
Letter
Synlett
Sodium chloro[(4-chlorophenyl)sulfonyl]azanide (2b),
an analogue of chloramine-T, was also tested for the synthe-
sis of N-arylsulfonamides 4a–i (Scheme 2). Azanide 2b was
normally less efficient than chloramine-T in its reaction
with arylboronic acid. For example, the reaction of com-
pound 2b with (4-bromophenyl)boronic acid gave the de-
sired N-arylsulfonamide 4h in 43% yield, whereas the corre-
sponding reaction of chloramine-T gave a 67% yield of 3i.
Additionally, 1-naphthylboronic acid was a good reaction
partner for the synthesis of the N-arylsulfonamide 4i in 57%
yield. To our surprise, sodium chloro(alkylsulfonyl)azanides
were not compatible with the reaction (results not shown).
Although the precise mechanism of the sulfamidation
reaction still remains uncertain, a possible reaction path-
way is proposed on the basis of previous studies (Scheme
3). Initially, transmetalation of the aryl group of the arylbo-
ronic acid with copper(II) and a subsequent ligand ex-
change with EtOK gives rise to species A, which is oxidized
by a second equivalent of Cu(II), to form Cu(I) and the inter-
mediate B; this is followed by C–O reductive elimination to
provide Cu(I) and byproduct C.15 Indeed, a trace of ethoxy-
benzene was observed by GC/MS analysis when the reac-
tion of chloramine-T (2a) with 4-tolylboronic acid (1k) was
carried out under the standard conditions. Subsequently,
species D is produced through oxidative addition of Cu(I) to
the N–Cl bond of chloramine-T; subsequent transmetala-
tion of the arylboronic acid generates intermediate E.8
Finally, a C–N reductive elimination of intermediate E deliv-
ers the desired N-arylsulfonamide and reforms the Cu(I)
catalyst.8a
Cu(OAc)2 (0.05 equiv)
tBuOK (1.5 equiv)
B(OH)2
NHTs
Na
Cl
N
Ts
+
Br
EtOH, Air
RT, 20 h
Br
1i
1.06 g (5.27 mmol)
2a
3i
1 g (4.39 mmol)
0.87 g (61%)
Scheme 4 Gram-scale sulfamidation of (4-bromophenyl)boronic acid
(1i)
In conclusion, we have developed a novel copper-cata-
lyzed Chan–Lam-coupling-like reaction of arylboronic acids
with sodium chloro(arylsulfonyl)azanides to give the corre-
sponding N-arylsulfonamides at room temperature and in
moderate to good yields with a good tolerance of functional
groups.16 In this process, we believe that the sodium
chloro(arylsulfonyl)azanide serves as an electrophile (in a
similar manner to halide) to oxidize the copper catalyst
through oxidative addition. Exploration of chloramine-
based chemistry for the synthesis of other bioactive motifs
is ongoing in our laboratory. The results will be published in
due course.
Funding Information
This work was supported by the National Natural Science Foundation
of China (No. 21502069), the Science and Technology Project of the
Education Department of Jiangxi Province (No. GJJ161236), and the
Key Discipline Project of Nanchang Normal University (No.
NSXK20141003).
N
oaitn
a
l
N
a
utarl
Secince
F
o
u
n
d
oaitn
of
C
h
n
i
a
2(
1
5
0
2
0
6
9
E)
d
u
coaitn
D
e
p
artm
e
nt
of
a
ni
J
g
x
i
Pi
orvnce
G(
1
J
6
1
2
3
6)
EtOK
+
Ar-B(OH)2
Acknowledgment
CuII
CuI
We are grateful to the Analysis and Testing Center of Jiangxi Normal
University for the analytical data.
Ar-CuII-OEt
CuII
Ar-CuIII-OEt
Ar-OEt
A
B
C
CuI
Na
Supporting Information
N
Ts
+
EtOH
Ar NHTs
Cl
Supporting information for this article is available online at
https://doi.org/10.1055/s-0036-1590978.
S
u
p
p
ortiInfogrmoaitn
S
u
p
p
o
nrtogI
f
rmoaitn
Cl-CuIII-NHTs
Ar-CuIII-NHTs
References and Notes
OEt
OEt
E
D
(1) (a) Agnihotri, G. Synlett 2005, 2857. (b) Minakata, S. Acc. Chem.
Res. 2009, 42, 1172. (c) Li, Z.; Capretto, D. A.; He, C. In Silver in
Organic Chemistry; Harmata, M., Ed.; Wiley: Oxford, 2010, Chap.
6, 16. (d) Goehring, R. R. In Handbook of Reagents for Organic
Synthesis: Catalytic Oxidation Reagents; Fuchs, P. L., Ed.; Wiley:
Chichester, 2013, 142.
(2) (a) Minakata, S.; Yoneda, Y.; Oderaotoshi, Y.; Komatsu, M. Org.
Lett. 2006, 8, 967. (b) Wu, X.-L.; Wang, G.-W. Eur. J. Org. Chem.
2008, 2008, 6239. (c) Hayakawa, J.; Kuzuhara, M.; Minakata, S.
Org. Biomol. Chem. 2010, 8, 1424. (d) Martínez, C.; Muñiz, K.
Adv. Synth. Catal. 2014, 356, 205.
B(OH)2OEt
Ar B(OH)2
+
EtOK
tBuOK
EtOH
+
Scheme 3 Proposed mechanism for the sulfamidation of arylboronic
acids
To demonstrate the potential synthetic application of
the present method, we attempted a sulfamidation of (4-
bromophenyl)boronic acid (1i) on a gram scale, and we ob-
tained the desired product 3i in 61% yield (Scheme 4).
© Georg Thieme Verlag Stuttgart · New York — Synlett 2017, 28, A–E

E
B. Ouyang et al.
Letter
Synlett
(3) (a) Li, G.; Chang, H.-T.; Sharpless, K. B. Angew. Chem. Int. Ed.
1996, 35, 451. (b) Rubin, A. E.; Sharpless, K. B. Angew. Chem. Int.
Ed. 1997, 36, 2637. (c) Sugimoto, H.; Mikami, A.; Kai, K.; Sajith,
P. K.; Shiota, Y.; Yoshizawa, K.; Asano, K.; Suzuki, T.; Itoh, S.
Inorg. Chem. 2015, 54, 7073.
M.; Shivashankar, K.; Kulkarni, M. V.; Rasal, V. P.; Patel, H.;
Mutha, S. S.; Mohite, A. A. Eur. J. Med. Chem. 2010, 45, 1151.
(e) Chohan, Z. H.; Youssoufi, M. H.; Jarrahpour, A.; Ben Hadda, T.
Eur. J. Med. Chem. 2010, 45, 1189.
(10) (a) Ley, S. V.; Thomas, A. W. Angew. Chem. Int. Ed. 2003, 42,
5400. (b) Ma, D.; Cai, Q. Acc. Chem. Res. 2008, 41, 1450. (c) Surry,
D. S.; Buchwald, S. L. Angew. Chem. Int. Ed. 2008, 47, 6338.
(d) Monnier, F.; Taillefer, M. Angew. Chem. Int. Ed. 2009, 48,
6954. (e) Qiao, J.; Lam, P. Synthesis 2011, 829. (f) Louillat, M. L.;
Patureau, F. W. Chem. Soc. Rev. 2014, 43, 901.
(11) Chan, D. M. T.; Monaco, K. L.; Wang, R.-P.; Winters, M. P. Tetra-
hedron Lett. 1998, 39, 2933.
(12) Lam, P. Y. S.; Vincent, G.; Clark, C. G.; Deudon, S.; Jadhav, P. K.
Tetrahedron Lett. 2001, 42, 3415.
(13) Nasrollahzadeh, M.; Ehsani, A.; Maham, M. Synlett 2014, 25,
505.
(14) Moon, S. Y.; Nam, J.; Rathwell, K.; Kim, W.-S. Org. Lett. 2014, 16,
338.
(15) (a) King, A. E.; Brunold, T. C.; Stahl, S. S. J. Am. Chem. Soc. 2009,
131, 5044. (b) King, A. E.; Huffman, L. M.; Casitas, A.; Costas, M.;
Ribas, X.; Stahl, S. S. J. Am. Chem. Soc. 2010, 132, 12068. (c) Rao,
D. N.; Rasheed, S.; Kumar, K. A.; Reddy, A. S.; Das, P. Adv. Synth.
Catal. 2016, 358, 2126.
(4) (a) Ando, T.; Minakata, S.; Ryu, I.; Komatsu, M. Tetrahedron Lett.
1998, 39, 309. (b) Ando, T.; Kano, D.; Minakata, S.; Ryu, I.;
Komatsu, M. Tetrahedron 1998, 54, 13485. (c) Jeong, J. U.; Tao,
B.; Sagasser, I.; Henniges, H.; Sharpless, K. B. J. Am. Chem. Soc.
1998, 120, 6844. (d) Antunes, A. M. M.; Marto, S. J. L.; Branco, P.
S.; Prabhakar, S.; Lobo, A. M. Chem. Commun. 2001, 405.
(e) Kano, D.; Minakata, S.; Komatsu, M. J. Chem. Soc., Perkin
Trans. 1 2001, 3186. (f) Kumar, G. D.; Baskaran, S. Chem.
Commun. 2004, 1026. (g) Vyas, R.; Gao, G.-Y.; Harden, J. D.;
Zhang, X. P. Org. Lett. 2004, 6, 1907. (h) Minakata, S.; Kano, D.;
Oderaotoshi, Y.; Komatsu, M. Angew. Chem. Int. Ed. 2004, 43, 79.
(i) Gao, G.-Y.; Harden, J. D.; Zhang, X. P. Org. Lett. 2005, 7, 3191.
(5) (a) Albone, D. P.; Aujla, P. S.; Taylor, P. C. J. Org. Chem. 1998, 63,
9569. (b) Albone, D. P.; Challenger, S.; Derrick, A. M.; Fillery, S.
M.; Irwin, J. L.; Parsons, C. M.; Takada, H.; Taylor, P. C.; Wilson, D.
J. Org. Biomol. Chem. 2005, 3, 107. (c) Baumann, T.; Bachle, M.;
Brase, S. Org. Lett. 2006, 8, 3797. (d) Bhuyan, R.; Nicholas, K. M.
Org. Lett. 2007, 9, 3957. (e) Harden, J. D.; Ruppel, J. V.; Gao, G.-Y.;
Zhang, X. P. Chem. Commun. 2007, 4644. (f) Takeda, Y.;
Hayakawa, J.; Yano, K.; Minakata, S. Chem. Lett. 2012, 41, 1672.
(6) Jigajinni, V. B.; Pelter, A.; Smith, K. Tetrahedron Lett. 1978, 19,
181.
(16) Reaction of Chloramines 2 with Arylboronic Acids 1; General
Procedure
A test tube equipped with a stirrer bar was charged with the
appropriate chloramine
2 (0.3 mmol), arylboronic acid 1
(7) (a) Minakata, S.; Kano, D.; Oderaotoshi, Y.; Komatsu, M. Org.
Lett. 2002, 4, 2097. (b) Ganesh, V.; Sureshkumar, D.; Chanda, D.;
Chandrasekaran, S. Chem. Eur. J. 2012, 18, 12498.
(8) (a) Kawano, T.; Hirano, K.; Satoh, T.; Miura, M. J. Am. Chem. Soc.
2010, 132, 6900. (b) Liu, X.-Y.; Gao, P.; Shen, Y.-W.; Lianga, Y.-M.
Adv. Synth. Catal. 2011, 353, 3157.
(9) (a) Scozzafava, A.; Owa, T.; Mastrolorenzo, A.; Supuran, C. T.
Curr. Med. Chem. 2003, 10, 925. (b) Eschenburg, S.; Priestman,
M. A.; Abdul-Latif, F. A.; Delachaume, C.; Fassy, F.; Schönbrunn,
E. J. Biol. Chem. 2005, 280, 14070. (c) Stanton, M. G.; Stauffer, S.
R.; Gregro, A. R.; Steinbeiser, M.; Nantermet, P.;
Sankaranarayanan, S.; Price, E. A.; Wu, G.; Crouthamel, M.-C.;
Ellis, J.; Lai, M.-T.; Espeseth, A. S.; Shi, X.-P.; Jin, L.; Colussi, D.;
Pietrak, B.; Huang, Q.; Xu, M.; Simon, A. J.; Graham, S. L.; Vacca,
J. P.; Selnick, H. J. Med. Chem. 2007, 50, 3431. (d) Basanagouda,
(0.36 mmol), and t-BuOK (50.5 mg, 0.45 mmol). A solution of
Cu(OAc)2 (2.7 mg, 0.015 mmol) in EtOH (1.5 mL) was then
added, and the mixture was stirred under air at RT for 12 h. The
heterogeneous mixture was then diluted with EtOAc (1 mL), and
the resulting mixture was filtered through a pad of silica gel,
which was washed with EtOAc (3 mL). The organic solutions
were combined, and the solvent was removed under reduced
pressure. The crude product was purified by column chroma-
tography (silica gel, PE–EtOAc).
4-Methyl-N-phenylbenzenesulfonamide (3a)
White solid; yield: 46 mg (62%); mp 100–101 °C. 1H NMR (400
MHz, CDCl3): δ = 7.67 (d, J = 8.3 Hz, 2 H), 7.22 (t, J = 7.9 Hz, 4 H),
7.09 (dd, J = 9.4, 8.3 Hz, 3 H), 6.97 (s, 1 H), 2.37 (s, 3 H). 13C NMR
(101 MHz, CDCl3): δ = 143.87, 136.58, 136.14, 129.65, 129.30,
127.29, 125.30, 121.57, 21.52.
© Georg Thieme Verlag Stuttgart · New York — Synlett 2017, 28, A–E