A convenient and efficient copper-catalyzed synthesis of unsymmetrical and symmetrical diaryl chalcogenides from arylboronic acids in ethanol at room temperature

Article abstract of DOI:10.1016/j.tet.2014.01.030

A simple and convenient approach for the synthesis of unsymmetrical diaryl chalcogenides (Te, Se, and S) has been developed by copper-catalyzed cross-coupling reaction of organoboronic acid with diaryl dichalcogenide in ethanol using NaBH₄ in air or oxygen. The present methodology is highly practical for the synthesis of unsymmetrical diaryl tellurides with various functionalities such as -NO₂, -F, -Br, and -COOH that have been obtained in good to excellent yields. Methodology is also effective for the synthesis of unsymmetrical diaryl selenides and sulfides. Moreover, symmetrical diaryl selenides have also been obtained from arylboronic acids using elemental selenium powder under optimized reaction conditions. The use of NaBH ₄ is the key for the development of milder reaction conditions, which enable the construction of unsymmetrical diaryl chalcogenides from boronic acid substrates in ethanol at room temperature.

Full text of DOI:10.1016/j.tet.2014.01.030

Tetrahedron 70 (2014) 1763e1772
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A convenient and efficient copper-catalyzed synthesis of
unsymmetrical and symmetrical diaryl chalcogenides from
arylboronic acids in ethanol at room temperature
*
Amit Kumar, Sangit Kumar
Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal, MP 462 066, India
a r t i c l e i n f o
a b s t r a c t
Article history:
A simple and convenient approach for the synthesis of unsymmetrical diaryl chalcogenides (Te, Se, and S)
has been developed by copper-catalyzed cross-coupling reaction of organoboronic acid with diaryl di-
chalcogenide in ethanol using NaBH4 in air or oxygen. The present methodology is highly practical for the
synthesis of unsymmetrical diaryl tellurides with various functionalities such as eNO2, eF, eBr, and
eCOOH that have been obtained in good to excellent yields. Methodology is also effective for the syn-
thesis of unsymmetrical diaryl selenides and sulfides. Moreover, symmetrical diaryl selenides have also
been obtained from arylboronic acids using elemental selenium powder under optimized reaction
conditions. The use of NaBH4 is the key for the development of milder reaction conditions, which enable
the construction of unsymmetrical diaryl chalcogenides from boronic acid substrates in ethanol at room
temperature.
Received 2 December 2013
Received in revised form 14 January 2014
Accepted 16 January 2014
Available online 24 January 2014
Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction
a stoichiometric amount of copper metal is used in the synthesis of
symmetrical diaryl tellurides from diaryl ditellurides at ambient
Synthesis of unsymmetrical organochalcogenides (chalcogens S,
Se, and Te) is an attractive area of research due to their usage as
convenient intermediates and reagents in organic synthesis.1,2
Apart from synthetic applications, organochalcogen structural
motifs display important properties like fluorescence, biological
activities and have applications in material sciences.3 A number of
methods are available in the literature for the synthesis of un-
symmetrical chalcogenides making use of transition metal cata-
lysts. Various metals including palladium, nickel, iron, rhodium,
indium, and copper have been utilized to catalyze the reaction of
aryl halides with thiol/seleno dichalcogenide.4e6 Particular interest
is the transition metal catalyzed synthesis of unsymmetrical diaryl
tellurides. Although, the transition metal catalyzed synthesis of
carbonesulfur and carboneselenium is very well established,
however, catalytic methods for the synthesis of unsymmetrical
diaryl tellurides are rare. Synthesis of diorgano tellurides is difficult
attributed to weak telluriumecarbon bond, metallic character, and
oxidizing nature of tellurium. Because of labile carbonetellurium
bond and metallic nature, synthesis of organotellurides is often
sluggish and leads to undesired reaction mixture. Moreover,
temperature.7 Diaryl ditellurides are the precursors for the syn-
thesis of unsymmetrical diaryl telluride; therefore, it is desirable to
use low catalyst loading and low temperature to avoid undesired
formation of symmetrical diaryl telluride. Similarly, organo-
tellurium compounds often tend to convert into telluroxides under
oxidative reaction conditions.8d
Organoboronic acids are widely used as coupling partners in
various coupling reactions due to their commercial availability,
stability, and compatibility with a variety of functional groups.9 The
first reaction of organoboronic acids with diaryl tellurides, sele-
nides, and sulfides has been discovered by Wang and Taniguchi
using CuI as a catalyst in DMSO at 100 ꢀC.10a,b Subsequently various
groups have synthesized unsymmetrical diaryl sulfides and sele-
nides; however, not tellurides, using organoboronic acid and
dichalcogenide/thiol with improved reaction conditions.10 But all
the developed methodologies associated with some disadvantages
like limited substrate scope, high reaction temperature, expensive
catalyst, toxic solvent, and longer reaction time.10c,e,f
Recently, a transition metal free synthesis of unsymmetrical
diaryl chalcogenide from arene and dichalcogenides (S, Se, Te) has
been studied by our group under oxidative condition using a per-
sulfate oxidant in trifluoroacetic acid.8d However, methodology
showed compatibility only with electron-rich arenes and also oxi-
dation of tellurides into telluroxides were observed. Moreover, we
have also developed potassium tert-butoxide mediated synthesis of
* Corresponding author. E-mail addresses: sangitkumar@iiserb.ac.in, sangitk@
gmail.com, sangitk@gmail.com (S. Kumar).
0040-4020/$ e see front matter Ó 2014 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2014.01.030

1764
A. Kumar, S. Kumar / Tetrahedron 70 (2014) 1763e1772
unsymmetrical chalcogenides (S, Se) from dichalcogenides with
bromo arenes in DMSO. This methodology is only used in the
synthesis of sulfides and selenides and failed to provide un-
symmetrical diaryl tellurides under similar conditions.8e As a part
of our ongoing research devoted to the synthesis of unsymmetrical
organochalcogenides using new benign and practical methods,8
herein we wish to report a convenient and highly efficient
copper-catalyzed cross-coupling of organoboronic acid with diaryl
dichalcogenide in ethanol as a solvent at room temperature.
provided practical yield of diaryl telluride 1. The excess of NaBH4
has the negative effect on yield of the product 1 as reaction gave
30% of biaryl side product 4,40-dimethoxy-1,10-biphenyl with 62%
of product 1, when 4 equiv of NaBH4 was used (Table 1 entry 15).
On the other hand, 1 equiv of NaBH4 gave no side product, how-
ever, reaction completed in long time (Table 1 entry 15). NaBH4 of
2.5 equiv noticed to be optimum for maximum yield of the un-
symmetrical diaryl telluride 1. Both air and oxygen were effective
as an oxidant for the completion of reaction. The presence of ox-
idant is crucial in the reaction mixture as only trace amount of
diaryl telluride 1 is formed in the absence of air. Next, trie-
thylborane was used as an additive instead of NaBH4 in the car-
bonetellurium bond forming reaction. Reaction proceeded
smoothly, however, required longer time (30 h) for the completion
of the reaction (Table 1 entry 16). Sodium hydride was also
screened in the reaction and yielded 59% of desired product 1
(Table 1 entry 17).
In order to evaluate the scope and limitation of this protocol, we
explored the generality of our methodology with substituted
arylboronic acid substrates (Table 2). In general both electron-poor
and electron-rich substrates afforded good to excellent yields of the
corresponding unsymmetrical diaryl tellurides (1e15). Several
functional groups such as eCOMe, eCN, eCH3, eOMe, eCOOH,
eNO2, eF, eCl, and eBr showed compatibility with the developed
protocol. Also heteroaryl substrate 3-pyridineboronic acid and 2-
methoxy-5-(phenyltellanyl)pyridine gave corresponding tellurides
18 and 20 in 71% and 67% yields (Table 2, entries 17 and 20). Other
aromatic boronic acids such as 1-naphthaleneboronic and 2-
2. Results and discussion
For
the
optimization
of
reaction
conditions,
4-
methoxyphenylboronic acid and diphenyl ditelluride were chosen
as the substrates and varied various parameters such as catalyst
loading, solvent, and reductant. Among several catalysts screened
(Table 1), CuI and CuSO4$5H2O were found to be most efficient for
the carbonetellurium bond formation. Due to low-cost and
ready availability of CuSO4$5H2O, we selected copper sulfate pen-
tahydrate for rest of the reaction optimizations. Various bidentate
ligands like 1,10-phenanthroline, 2,20-bipyridyl, tetramethylethyle-
nediamine (TMEDA), and dimethylethylenediamine (DMEDA)
were employed for the reaction. Out of these 1,10-phenanthroline
was found to be the most suitable ligand for the maximum out-
come in the CeTe bond formation reaction. Both copper sulfate
pentahydrate and 1,10-phenanthroline are indispensable in the re-
action as the absence of either one failed to provide any diaryl tel-
luride 1.
Table 1
Optimization of reaction conditionsa
Entry
Copper salt (mol %)b
Ligand (L)
Reductantc
Time (h)
Yieldd (%)
1
2
3
Cu2O
1,10-Phen
1,10-Phen
1,10-Phen
1,10-Phen
1,10-Phen
1,10-Phen
1,10-Phen
Bipyridyl
TMEDA
NaBH4
NaBH4
NaBH4
NaBH4
NaBH4
NaBH4
NaBH4
Cs2CO3
KOtBu
NaBH4
Na2CO3
d
5
5
6
5
8
5
5
5
5
55
51
23
92
Trace
81
90
49
39
Cu(OAc)2.H2O
Cu-Powder
CuI
CuI
CuSO4
CuSO4$5H2O
CuSO4$5H2O
CuSO4$5H2O
CuSO4$5H2O
CuSO4$5H2O
CuSO4$5H2O
CuSO4$5H2O
d
4
5e
6
7
8
9
10
11
12
13
14
15
16
17
DMEDA
5
5
34
62
1,10-Phen
1,10-Phen
d
24
24
24
d
30
8
Nil
10
Nil
85,f 62g
60
NaBH4
NaBH4
NaBH4
B(C2H5)3
NaH
1,10-Phen
1,10-Phen
1,10-Phen
1,10-Phen
CuSO4$5H2O
CuSO4$5H2O
CuSO4$5H2O
h
59
a
Reaction was carried out at 0.5 mmol scale using 0.5 mmol of diphenyl ditelluride and 1.2 mmol of 4-methoxyphenylboronic acid in 3 mL of ethanol at room temperature.
Catalyst of 5 mol %used.
Reductant of 2e2.5 equiv used.
Isolated yield based on diphenyl ditelluride.
Reaction carried out in DMSO as solvent.
Reaction mixture stirred for 14 h using 1 equiv NaBH4.
Reaction was carried out with 4 equiv of NaBH4 for 3 h.
Solution of 1 M B(C2H5)3 in THF was used.
b
c
d
e
f
g
h
We have also screened various reductants in the optimization
naphathaleneboronic acids furnished the corresponding naphthyl
tellurides 16 and 17 in 82 and 91% yields, respectively (Table 2,
entries 15 and 16). Next, we attempted the reaction of alkyl iso-
propyl boronic acid with diphenyl ditelluride under optimized
condition. Unfortunately reaction did not afford the isopropyl
phenyl telluride.
of reaction conditions. Additives such as Mg, Al, and Zn failed to
improve the outcome of the reaction. Similarly, KOtBu and Cs2CO3
bases were noticed to be ineffective (desired telluride 1 obtained
in 39% and 49%, respectively) under our reaction conditions. So-
dium carbonate provided 62% yield of telluride 1. The use of NaBH4

A. Kumar, S. Kumar / Tetrahedron 70 (2014) 1763e1772
1765
Table 2
CuSO4$5H2O catalyzed coupling of diaryl ditelluride with organoboronic acid
Entry
1
Boronic acid
Telluride
Yield (%)
2
3
98
93
2
3
4
4
5
90
91
5
6
7
8
6
7
8
9
81
89
85
88
9
10
11
87
79
10
11
12
12
13
82
91
13
14
82
14
15
15
16
40 (68)a
82
(continued on next page)

1766
A. Kumar, S. Kumar / Tetrahedron 70 (2014) 1763e1772
Table 2 (continued )
Entry
Boronic acid
Telluride
Yield (%)
91
16
17
18
19
17
71
88
18b
19b
20
20
21
85
67
a
CuI used as catalyst.
1,2-Bis(4-methoxyphenyl)ditellane was used.
b
We have also studied different arylboronic substrates with
ditelluride to see the compatibility of various arylboronic substrates
(Scheme 1). Indeed, diphenyl ditelluride coupled with potassium
phenyltrifluoroborate and phenylboronic acid pinacol ester
under optimized reaction conditions and provided comparable
yields of diphenyl telluride (97% and 94% vs 98%). After exploiting
various arylboronic substrates, we attempted to study 4-
methoxyiodoanisole as a substrate under optimized reaction con-
ditions. Unfortunately, reaction failed to give unsymmetrical diaryl
telluride under optimized reaction conditions and presumably due
to poor reactivity of aryl iodide.
To further demonstrate the practicability of the given procedure,
we tested the synthesis of symmetrical diaryl selenides with sele-
nium powder and organoboronic acids. The symmetrical diaryl
selenides 22 and 55e58 were produced in good yields as men-
tioned in Table 5.
3. Mechanism
A plausible mechanism with two paths I and II is depicted in
Scheme 2. Diaryl dichalcogenide reduced by NaBH4 leading sodium
chalcogenolate, which involve in both the paths I and II. In path I,
Scheme 1. Coupling with different boronic acids.
Then, we next turned our attention to explore the same protocol
for the synthesis of diaryl selenides and sulfides using various
organoboronic acids and diaryldiselenide/disulfides (Tables 3 and
4). As expected, unsymmetrical monoselenides 22e42 were ob-
tained in good yields, which were not affected by the nature or
steric hindrance of substituted groups near to reaction center in the
organoboronic acid.
The reaction of organoboronic acids with diaryldisulfides fur-
nished low yield of corresponding product compared to diselenides
and ditellurides. ortho-Aminosubstituted disulfide has shown good
compatibility with the arylboronic acids under optimization re-
action conditions (entries 1e7, Table 4). In a separate experiment
we found that the rate of the reaction in the order of Te>Se>S when
reaction between 4-methoxyphenylboronic acid and diphenyldi-
selenide/telluride/sulfide was carried out. This is probably due to
the stronger SeS bond present in diaryl disulfide or could be due to
poor nucleophilic nature of arylthiolate (Arsꢁ).10f
Table 3
CuSO4$5H2O catalyzed coupling of diphenyldiselenide with organoboronic acids
Entry
1
Boronic acid
Selenide
Yield (%)
96
22
23
2
3
89
92
24

A. Kumar, S. Kumar / Tetrahedron 70 (2014) 1763e1772
1767
Table 3 (continued )
Table 4
CuSO4$5H2O catalyzed coupling of 2,20-disulfanediyldianiline with arylboronic acid
Entry
Boronic acid
Selenide
Yield (%)
94
4
25
26
Entry
1
Substrate
Arylsulfide
Yield (%)
82
5
6
82
89
43
44
27
28
29
2
3
4
71
73
86
7
8
68
89
45
46
9
30
31
32
33
34
87
93
82
88
79
5
6
47
48
80
79
10
11
12
13
7
8
49
71
50
51
77
68
9a
14
15
16
35
36
37
76
92
86
a
1,2-Bis(4-methoxyphenyl)disulfane was used.
Table 5
Synthesis of symmetrical diaryl selenides
17
18
38
39
79
63
Entry
1
Diarylselenide
Yield (%)
93
22
52
53
19
20
40
46 (69)a
2
3
82
61
41
42
82
61
21
4
54
72
a
(continued on next page)
CuI used as catalyst.

1768
A. Kumar, S. Kumar / Tetrahedron 70 (2014) 1763e1772
Table 5 (continued )
4. Conclusions
Entry
Diarylselenide
Yield (%)
In summary, we have developed a convenient and highly effi-
cient copper-catalyzed cross-coupling reaction of organoboronic
acid with diaryl dichalcogenide in ethanol at room temperature. A
wide variety of organoboronic acids with different substituted
groups afforded the desired unsymmetrical diaryl chalcogenides in
good to excellent yields. Also synthesis of symmetrical diaryl sel-
enides has been achieved under optimized reaction conditions
from selenium powder and arylboronic acids. Currently, we are
exploring the synthesis of key synthetic precursors diaryl dichal-
cogenides from boronic acid substrates.
5
6
7
55
56
57
83
69
76
5. Experimental section
5.1. General method for the synthesis of unsymmetrical
chalcogenides
8
58
59
In a 10 mL capacity round bottom flask diphenylditelluride
(202 mg, 0.5 mmol) and sodium borohydride (48 mg, 1.25 mmol)
Scheme 2. Proposed reaction mechanism.
chalcogenolate ion may undergo ligation with the Cu(II) catalyst A
and forms copperechalcogenolate intermediate B, which may react
with phenylboronic acid via trans-metalation to produce in-
termediate C. Reductive elimination could give desired telluride 1
and Cu(0). Copper(II) may be regenerated back through oxidation
by air or oxygen and thus complete the catalytic cycle.10k In path II,
chalcogenolate ion can undergo ligation with the Cu(I) catalyst F
and forms copperechalcogenolate intermediate G, which may un-
dergo oxidation from Cu(I) to Cu(II) in the presence of oxygen
forming intermediate H. Subsequently, trans-metalation of the aryl
group from boronic acid to the intermediate H could give C. Re-
ductive elimination of C may be led to the formation of the desired
telluride 1 and copper(0) D. Finally, Cu(0) oxidizes to Cu(I) in the
presence of oxygen.10a,b
It is worth noticing the involvement of boron in the reaction.
Triethylborane assists the formation of carbonetellurium bond
(vide supra, Table 1 entry 16). On the other hand, sodium hydride,
which does not have a boron atom is not an efficient promoter for
the carbonetellurium bond formation. It seems that sodium bo-
rohydride not only act as a reductant but also act as Lewis acid by
interacting with the tellurium center. This interaction between
boron and tellurium may facilitate reductive elimination and hence
facile formation of diaryl telluride 1.
were added in ethanol (3 mL). Reaction mixture was stirred at room
temperature for 10 min under nitrogen atmosphere. Then,
CuSO4$5H2O (0.025 mmol, 7 mg),1,10-phenanthroline (0.025 mmol,
6 mg), and (4-methoxyphenyl) boronic acid (183 mg,1.2 mmol) were
added sequentially. Reaction mixture was stirred in air for 5 h.
Progress of reaction was monitored by TLC. Then, reaction mixture
was poured in water (25 mL) and extracted with ethyl acetate
(3ꢂ20 mL). Combined organic layer was dried over (Na2SO4),
evaporated under reduced pressure at 40 ꢀC. Crude mixture was
purified by column chromatography (hexane/EtOAc, 9.5:0.5) to
provide the pure (4-mhethoxyphenyl)(phenyl)tellane 1 as a white
solid; yield: 282 mg (90%). Similar procedure was followed for the
synthesis of tellurides 2e21, selenides 22e42, sulfides 43e51 listed
in Tables 2e4. Synthesized compounds were characterized by 1H,
13C, 77Se, and 125Te NMR and mass spectrometry and spectroscopic
data appended below.
5.1.1. 4-Methoxyphenyl)(phenyl)tellane (1).10h Rf¼0.4 (1:9, ethyl
acetate/hexane); white solid; yield 0.29 g (90%). 1H NMR (400 MHz,
CDCl3)
d
7.74 (d, J¼8.6 Hz, 2H), 7.58 (m, 2H), 7.20 (m, 3H), 6.80 (d,
J¼8.6 Hz, 2H), 3.80 (s, 3H); 13C NMR (100 MHz, CDCl3)
d 160.1, 141.2,
136.5, 129.4, 127.3, 116.0, 115.6, 103.3, 55.2; 125Te NMR (126 MHz,
CDCl3)
d 664.9.

A. Kumar, S. Kumar / Tetrahedron 70 (2014) 1763e1772
1769
5.1.2. Diphenyltellane (2).10c Rf¼0.6 (hexane); liquid; yield 0.28 g
(100 MHz, CDCl3)
d
148.5, 142.3, 139.5, 131.0, 130.0, 129.9, 129.0,
(98%). 1H NMR (400 MHz, CDCl3)
d
7.72 (d, J¼6.8 Hz, 4H), 7.30
122.4, 116.9, 113.1; 125Te NMR (126 MHz, CDCl3)
d 735.8.
(t, J¼6.8 Hz, 2H), 7.22 (t, J¼6.8 Hz, 4H); 13C NMR (100 MHz,
CDCl3)
d
138.0, 129.5, 127.9, 114.4; 125Te NMR (126 MHz, CDCl3)
5.1.12. (4-Bromophenyl)(phenyl)tellane (12).10h Rf¼0.6 (hexane);
d
689.8.
liquid; yield 0.29 g (82%). 1H NMR (400 MHz, CDCl3)
d 7.70e7.68 (m,
2H), 7.50 (d, J¼8.3 Hz, 2H), 7.32e7.28 (m, 3H), 7.24e7.20 (m, 2H);
13C NMR (100 MHz, CDCl3)
139.4, 138.3, 132.6, 129.7, 128.2, 122.5,
114.3, 113.2; 125Te NMR (126 MHz, CDCl3)
695.4.
5.1.3. Phenyl(p-tolyl)tellane (3).14 Rf¼0.6 (hexane); liquid; yield
d
0.27 g (93%). 1H NMR (400 MHz, CDCl3)
d
7.70 (dd, J¼7.9, 1.3 Hz, 4H),
d
7.30e7.28 (m, 1H), 7.26e7.22 (m, 2H), 7.10 (d, J¼7.6 Hz, 2H), 2.40
(s, 3H); 13C NMR (100 MHz, CDCl3)
138.8, 138.1, 137.3, 130.5, 129.5,
127.6, 115.3, 110.3, 21.3; 125Te NMR (126 MHz, CDCl3)
674.8.
d
5.1.13. 2-(Phenyltellanyl)benzofuran (13). Rf¼0.3 (1:9 ethyl acetate/
d
hexane); white solid; yield 0.29 g (91%). 1H NMR (400 MHz, CDCl3)
d
7.76 (dd, J¼8.2, 1.3 Hz, 2H), 7.59 (d, J¼8.2 Hz, 1H), 7.55 (d, J¼8.2 Hz,
1H), 7.33e7.23 (m, 6H); 13C NMR (100 MHz, CDCl3)
159.2, 137.2,
129.7, 128.9, 128.2, 127.0, 124.8, 122.8, 122.4, 120.5, 114.1, 111.2; 125Te
NMR (126 MHz, CDCl3) 557.8; HRMS (APCI) m/z 323.9787, calcd
5.1.4. Phenyl(o-tolyl)tellane (4).10c Rf¼0.6 (hexane); liquid; yield
d
0.90 g (90%). 1H NMR (400 MHz, CDCl3)
d
7.76 (dd, J¼8.2,1.3 Hz, 2H),
7.55 (d, J¼7.6 Hz, 1H), 7.39e7.35 (m, 1H), 7.31e7.24 (m, 4H), 7.02
d
(t, J¼7.2 Hz, 1H), 2.48 (s, 3H); 13C NMR (100 MHz, CDCl3)
d
141.9,
for C14H10OTeþH: 323.9793.
138.7, 137.5, 129.7, 129.4, 128.2, 128.1, 126.8, 126.1, 119.3, 114.1; 125Te
NMR (126 MHz, CDCl3)
d
591.3.
5.1.14. 1-(4-(Phenyltellanyl)phenyl)ethanone (14).10l Rf¼0.4 (1:9,
ethyl acetate/hexane); yellow solid; yield 0.27 g (82%). 1H NMR
5.1.5. Phenyl(m-tolyl)tellane (5).10c Rf¼0.6 (hexane); liquid; yield
(400 MHz, CDCl3)
(d, J¼8.4 Hz, 2H), 7.36 (t, J¼7.6 Hz, 1H), 7.2e7.24 (m, 2H), 2.54 (s,
3H); 13C NMR (100 MHz, CDCl3)
197.6, 139.6, 136.0, 135.9, 129.9,
128.8, 128.7, 123.6,113.3, 26.5; 125Te NMR (126 MHz, CDCl3)
703.9;
d
7.79 (d, J¼8.1 Hz, 2H), 7.71 (d, J¼8.4 Hz, 2H), 7.59
0.27 g (91%). 1H NMR (400 MHz, CDCl3)
d 7.68 (m,2H), 7.57 (s, 1H),
7.50 (m, 1H), 7.29e7.25 (m, 1H), 7.20 (t, J¼7.4 Hz, 2H), 7.11e7.09 (m,
2H), 2.29 (s, 3H); 13C NMR (100 MHz, CDCl3)
139.2, 128.8, 137.8,
135.2, 129.5, 129.3, 128.8, 127.7, 114.8, 114.4, 21.2; 125Te NMR
(126 MHz, CDCl3) 685.2.
d
d
d
HRMS (APCI) m/z 326.9994, calcd for C13H12OTeþH: 327.0024.
d
5.1.15. 4-(Phenyltellanyl)benzoic acid (15).10h Rf¼0.3 (2:8, ethyl ac-
5.1.6. Phenyl(4-(trifluoromethyl)phenyl)tellane (6).6b Rf¼0.6 (hex-
etate/hexane); white solid; yield 0.13 g (40%). 1H NMR (400 MHz,
ane); liquid; yield 0.28 g (81%). 1H NMR (400 MHz, CDCl3)
CDCl3)
d
7.86e7.80 (m, 4H), 7.59 (d, J¼8.5 Hz, 2H), 7.38 (t, J¼7.2 Hz,
d
7.80e7.78 (m, 2H), 7.65 (d, J¼8.2 Hz, 2H), 7.41e7.35 (m, 3H),
7.29e7.25 (m, 2H), 13C NMR (100 MHz, CDCl3)
139.4, 138.0, 136.4,
129.9, 128.7, 125.9 (q), 122.8, 121.0, 113.3, 125Te NMR (126 MHz,
CDCl3) 709.3.
1H), 7.28 (t, J¼7.2 Hz, 2H); 13C NMR (100 MHz, CDCl3)
d 171.7, 139.7,
d
135.6, 130.6, 129.9, 128.8, 128.0, 125.2, 113.2; 125Te NMR (126 MHz,
CDCl3)
d 707.8.
d
5.1.16. Naphthalen-1-yl(phenyl)tellane (16).6b Rf¼0.5 (hexane); liq-
5.1.7. (4-Chlorophenyl)(phenyl)tellane (7).10c Rf¼0.7 (hexane); liq-
uid; yield 0.22 g (82%). 1H NMR (400 MHz, CDCl3)
d 8.19e8.08 (m,
uid; yield 0.28 g (89%). 1H NMR (400 MHz, CDCl3)
d
7.76 (dd, J¼8.2,
1H), 7.91 (dd, J¼7.1, 0.9 Hz, 1H), 7.76e7.71 (m, 2H), 7.54e7.52 (m,
1.3 Hz, 2H), 7.63 (d, J¼8.2 Hz, 2H), 7.36e7.24 (m, 1H), 7.27 (d,
2H), 7.45e7.39 (m, 2H), 7.22e7.14 (m, 2H), 7.08 (t, J¼7.1 Hz, 2H); 13
C
J¼7.8 Hz, 2H), 7.22e7.20 (m, 2H); 13C NMR (100 MHz, CDCl3)
NMR (100 MHz, CDCl3) d 138.8,137.6, 137.5, 135.9,133.7, 131.7, 129.5,
d
139.2, 138.2, 134.4, 129.8, 129.7, 128.1, 114.4, 112.4; 125Te NMR
128.8, 127.7, 127.0, 126.6, 126.3, 117.8, 114.8; 125Te NMR (126 MHz,
CDCl3) 570.8.
(126 MHz, CDCl3)
d
694.5.
d
5.1.8. (3,4-Dichlorophenyl)(phenyl)tellane (8). Rf¼0.6 (hexane); liq-
uid; yield 0.30 g (85%). 1H NMR (400 MHz, CDCl3)
7.75e7.72 (m,
2H), 7.69 (d, J¼1.6 Hz, 1H), 7.41 (dd, J¼8.3, 1.6 Hz, 1H), 7.34 (m, 1H),
7.28e7.21 (m, 3H); 13C NMR (100 MHz, CDCl3)
138.8, 138.6, 136.5,
133.3, 132.3, 131.2, 129.8, 128.6, 113.8, 113.7; 125Te NMR (126 M Hz,
CDCl3)
5.1.17. Naphthalen-2-yl(phenyl)tellane (17).10 Rf¼0.4 (hexane); yel-
d
low solid; yield 0.30 g (91%). 1H NMR (400 MHz, CDCl3)
d 8.24 (s,
1H), 7.79 (m, 1H), 7.74e7.71 (m, 4H), 7.66 (d, J¼8.4 Hz, 1H),
d
7,49e7.46 (m, 2H), 7.30e7.26 (m, 1H), 7.22 (t, J¼7.2 Hz, 2H); 13C
NMR (100 MHz, CDCl3)
d 137.9, 137.8, 134.8, 134.3, 132.6, 129.6,
d
720.7; HRMS (APCI) m/z 352.9134, calcd for C12H8Cl2TeþH:
128.7, 128.9, 127.8, 127.4, 126.4, 126.3, 114.8, 112.0; 125Te NMR
(126 MHz, CDCl3) 691.9.
352.9143.
d
5.1.9. 4-(Phenyltellanyl)benzonitrile (9).10l Rf¼0.3 (1:9, ethyl ace-
5.1.18. 3-(Phenyltellanyl)pyridine (18).5g Rf¼0.4 (1:9, ethyl acetate/
tate/hexane); yellow solid; yield 0.27 g (88%). 1H NMR (400 MHz,
hexane); semisolid; yield 0.20 g (71%). 1H NMR (400 MHz, CDCl3)
CDCl3)
d
7.82 (m, 2H), 7.54 (d, J¼8.0 Hz, 2H), 7.42e7.36 (m, 3H), 7.30
d
8.77 (s, 1H), 8.42 (dd, J¼4.7, 1.2 Hz, 1H), 7.88 (td, J¼7.7, 1.7 Hz, 1H),
7.65 (d, J¼8.2 Hz, 2H), 7.25 (t, J¼7.4 Hz, 1H), 7.19e7.14 (m, 2H),
7.09e7.06 (m, 1H); 13C NMR (100 MHz, CDCl3)
157.0, 148.6, 144.9,
138.5, 129.7, 128.4, 124.7, 113.3, 112.5; 125Te NMR (126 MHz, CDCl3)
652.5.
(t, J¼7.3 Hz, 2H); 13C NMR (100 MHz, CDCl3)
d 140.1, 135.7, 132.2,
130.1, 129.2, 124.3, 118.7, 112.8, 110.6; 125Te NMR (126 MHz, CDCl3)
d
d
725.6.
d
5.1.10. 3-(Phenyltellanyl)benzonitrile (10).14 Rf¼0.3 (1:9, ethyl ace-
tate/hexane); yellow solid at 0 ꢀC; yield 0.27 g (87%). 1H NMR
5.1.19. (4-Bromophenyl)(4-methoxyphenyl)tellane
(19).19 Rf¼0.5
(400 MHz, CDCl3)
7.39e7.34 (m, 1H), 7.29e7.22 (m, 3H); 13C NMR (100 MHz, CDCl3)
140.7, 139.5, 139.4, 130.9, 130.0, 129.6, 128.9, 118.2, 116.8, 113.6,
113.1; 125Te NMR (126 MHz, CDCl3)
727.4.
d
7.80e7.76 (m, 4H), 7.49 (d, J¼7.5 Hz, 1H),
(1:9, ethyl acetate/hexane); light yellow solid; yield 0.34 g (88%). 1H
NMR (400 MHz, CDCl3)
d
7.71 (d, J¼8.6 Hz, 2H), 7.37 (d, J¼8.6 Hz,
d
2H), 7.26 (d, J¼8.5 Hz, 2H), 6.79 (d, J¼8.5 Hz, 2H), 3.79 (s, 3H); 13C
d
NMR (100 MHz, CDCl3) d 160.2, 141.4, 137.8, 132.4, 121.8, 115.7, 114.5,
102.9, 55.2; 125Te NMR (126 MHz, CDCl3)
d 671.0.
5.1.11. (3-Nitrophenyl)(phenyl)tellane (11).12 Rf¼0.4 (1:9, ethyl ace-
tate/hexane); yellow liquid; yield 0.25 g (79%). 1H NMR (400 MHz,
5.1.20. Bis(4-methoxyphenyl)tellane (20).2f Rf¼0.4 (1:9, ethyl ace-
CDCl3)
d
8.41 (s, 1H), 8.06e8.04 (m, 1H), 7.84 (dt, J¼7.6, 1.1 Hz, 1H),
tate/hexane); white solid; yield 0.34 g (85%). 1H NMR (400 MHz,
7.81e7.79 (m, 2H), 7.37 (t, J¼7.4, 1H), 7.33e7.26 (m, 3H); 13C NMR
CDCl3)
d
7.61 (d, J¼8.6 Hz, 4H), 6.75 (d, J¼8.6 Hz, 4H), 3.76 (s, 6H);

1770
A. Kumar, S. Kumar / Tetrahedron 70 (2014) 1763e1772
13C NMR (100 MHz, CDCl3)
d
159.7, 139.7, 115.4, 104.3, 55.2; 125Te
5.1.30. 4-(Phenylselanyl)benzonitrile(30).10m Rf¼0.4 (1:9, ethyl ace-
NMR (126 MHz, CDCl3)
d
649.8.
tate/hexane); liquid; yield 0.22 g (87%). 1H NMR (400 MHz, CDCl3)
d
7.59e7.57 (m, 2H), 7.43e7.37 (m, 5H), 7.31 (d, J¼8.5 Hz, 2H); 13C
5.1.21. 2-Methoxy-5-(phenyltellanyl)pyridine (21). Rf¼0.5 (1:9,
NMR (100 MHz, CDCl3) d 140.9, 135.6, 132.4, 130.3, 130.0, 129.2,
ethyl acetate/hexane); solid; yield 0.21 g (67%). 1H NMR (400 MHz,
127.5, 118.8, 109.6; 77Se NMR (76 MHz, CDCl3)
d 438.1; HRMS (APCI)
CDCl3)
d
8.53 (d, J¼1.7 Hz,1H), 7.92 (dd, J¼8.5, 2.1 Hz,1H), 7.58e7.56
m/z 259.9988, calcd for C13H9NSeþH: 259.9973.
(m, 2H), 7.21 (d, J¼7.0 Hz, 1H), 7.16 (t, J¼7.4 Hz, 2H), 6.64
(d, J¼8.5 Hz, 1H), 3.91 (s, 3H); 13C NMR (100 MHz, CDCl3)
d
164.1,
5.1.31. Phenyl(m-tolyl)selane (31).10m Rf¼0.6 (hexane); liquid; yield
156.6, 149.2, 136.8, 129.5, 127.7, 114.9, 112.6, 101.4, 53.5; 125Te NMR
0.23 g (93%). 1H NMR (400 MHz, CDCl3)
d 7.52e7.50 (m, 2H), 7.39 (s,
(126 MHz, CDCl3)
d
614.2.
1H), 7.30e7.28 (m, 4H), 7.21 (t, J¼7.5 Hz, 1H), 7.12 (d, J¼7.6 Hz, 1H),
2.35 (s, 3H); 13C NMR (100 MHz, CDCl3)
139.2, 133.9, 132.8, 131.5,
130.7,130.3,129.4,129.2,128.4,127.3, 21.4; 77Se NMR (76 MHz, CDCl3)
414.3; HRMS (APCI) m/z 248.0096, calcd for C13H12Se: 248.0099.
d
5.1.22. Diphenylselane (22).5g Rf¼0.6 (hexane); liquid; yield 0.22 g
(93%). 1H NMR (400 MHz, CDCl3)
d
7.47e7.45 (m, 4H), 7.27
d
7.24 (m, 6H); 13C NMR (100 MHz, CDCl3)
d
133.0, 131.1, 129.3,
127.3; 77Se NMR (76 MHz, CDCl3)
d
416.3; GC/MS (EI):
5.1.32. 3-(Phenylselanyl)benzonitrile(32).10m Rf¼0.3 (1:9, ethyl ace-
tR¼6.66 min, m/z¼234.
tate/hexane); liquid; yield 0.21 g (82%). 1H NMR (400 MHz, CDCl3)
d
7.57e7.51 (m, 4H), 7.46 (dt, J¼7.7, 1.3 Hz, 1H), 7.36e7.27 (m, 4H);
13C NMR (100 MHz, CDCl3)
135.5, 134.8, 134.4, 134.2, 130.2, 129.9,
129.7, 128.8, 128.5, 118.3, 113.4; 77Se NMR (76 MHz, CDCl3)
429.8;
5.1.23. Phenyl(o-tolyl)selane (23).5g Rf¼0.6 (hexane); liquid; yield
d
0.22 g (89%). 1H NMR (400 MHz, CDCl3)
d
7.41e7.39 (m, 2H), 7.34
d
(d, J¼7.9 Hz, 1H), 7.29e7.18 (m, 5H), 7.06 (td, J¼7.9, 1.9 Hz, 1H), 2.41
(s, 3H); 13C NMR (100 MHz, CDCl3)
139.9, 133.7, 132.8, 131.7, 130.8,
130.3, 129.4, 127.8, 127.2, 126.7, 22.4; 77Se NMR (76 MHz, CDCl3)
375.4.
HRMS (APCI) m/z 259.9964, calcd for C13H9NSeþH: 259.9973.
d
5.1.33. 3-Chlorophenyl(phenyl)selane (33).10m Rf¼0.6 (hexane); liq-
d
uid; yield 0.23 g (88%). 1H NMR (400 MHz, CDCl3)
d 7.55e7.52
(m, 2H), 7.42 (m, 1H), 7.33e7.29 (m, 4H), 7.23e7.15 (m, 2H); 13C
NMR (100 MHz, CDCl3) 135.0, 134.9, 133.6, 131.8, 130.3, 130.2,
129.8, 129.6, 128.1, 127.3; 77Se NMR (76 MHz, CDCl3)
426.9.
5.1.24. 4-Methoxyphenyl(phenyl)selane (24).10m Rf¼0.4 (1:9, ethyl
d
acetate/hexane); liquid; yield 0.24 g (92%). 1H NMR (400 MHz,
d
CDCl3)
6.84 (m, 2H), 3.80 (s, 3H); 13C NMR (100 MHz, CDCl3)
133.2, 130.9, 129.2, 126.5, 120.0, 115.1, 55.3; 77Se NMR (76 MHz,
CDCl3) 400.7; HRMS (APCI) m/z 264.0068, calcd for C13H12OSe:
d
7.51e7.49 (m, 2H), 7.34e7.31 (m, 2H), 7.23e7.17 (m, 3H),
d
159.8, 136.5,
5.1.34. (3,4-Dichlorophenyl)(phenyl)selane (34). Rf¼0.6 (hexane);
liquid; yield 0.24 g (79%). 1H NMR (400 MHz, CDCl3)
d 7.52e7.49 (m,
d
3H), 7.33e7.28 (m, 4H), 7.21 (d, J¼7.8 Hz, 1H); 13C NMR (100 MHz,
264.0048.
CDCl3) d 134.0, 133.4, 133.2, 131.6, 131.4, 131.3, 130.9, 129.7, 129.5,
128.3; 77Se NMR (76 MHz, CDCl3)
d 425.2; HRMS (APCI) m/z
5.1.25. Phenyl(p-tolyl)selane (25).10m Rf¼0.5 (hexane); liquid; yield
302.9189, calcd for C12H8Cl2SeþH: 302.9236.
0.23 g (94%). 1H NMR (400 MHz, CDCl3)
d 7.46e7.44 (m, 4H), 7.25
(m, 3H), 7.13 (d, J¼7.9 Hz, 2H), 2.37 (s, 3H); 13C NMR (100 MHz,
5.1.35. Naphthalen-2-yl(phenyl)selane (35).10m Rf¼0.4 (hexane);
CDCl3)
d
137.7, 134.0, 132.2, 132.1, 130.3, 129.3, 126.9, 126.8, 21.2;
white solid; yield 0.21 g (76%). 1H NMR (400 MHz, CDCl3)
d 7.99
77Se NMR (76 MHz, CDCl3)
calcd for C13H12Se: 248.0099.
d
408.1; HRMS (APCI) m/z 248.0115,
(s, 1H), 7.80 (m, 1H), 7.73 (d, J¼8.3 Hz, 2H), 7.54e7.45 (m, 5H), 7.28
(m, 3H); 13C NMR (100 MHz, CDCl3)
134.0, 132.9, 132.5, 132.1,
131.3, 130.5, 129.4, 128.8, 128.5, 127.8, 127.4, 127.3, 126.5, 126.3; 77Se
NMR (76 MHz, CDCl3) 417.5; HRMS (APCI) m/z 285.0194, calcd for
16H12SeþH: 285.0177.
d
5.1.26. (4-Fluorophenyl)(phenyl)selane (26).10m Rf¼0.7 (hexane);
d
liquid yield 0.21 g (82%). 1H NMR (400 MHz, CDCl3)
d
7.50e7.47 (m,
C
2H), 7.42e7.40 (m, 2H), 7.29e7.25 (m, 3H), 6.99 (m, 2H); 13C NMR
(100 MHz, CDCl3)
d
163.8, 161.3, 135.8 (d), 132.2, 131.7, 129.3, 127.2,
5.1.36. 2-(Phenylselanyl)benzofuran (36).10m Rf¼0.5 (1:9, ethyl ace-
125.3, 125.2, 116.7, 116.5; 77Se NMR (76 MHz, CDCl3)
d
410.1; HRMS
tate/hexane); yellow solid; yield 0.25 g (92%). 1H NMR (400 MHz,
(APCI) m/z 251.9843, calcd for C12H9FSe: 251.9848.
CDCl3)
7.04 (s, 1H); 13C NMR (100 MHz, CDCl3)
129.5, 128.6, 127.6, 124.9, 123.0, 120.7, 115.9, 111.3; 77Se NMR
(76 MHz, CDCl3) 333.5; HRMS (APCI) m/z 273.9915, calcd for
C14H10OSe: 273.9892.
d
7.55 (d, J¼7.6 Hz,1H), 7.50e7.47 (m, 3H), 7.30e7.21 (m, 5H),
d
157.5, 143.6, 131.7, 129.9,
5.1.27. 4-Chlorophenyl(phenyl)selane (27).10m Rf¼0.6 (hexane); liq-
uid; yield 0.24 g (89%). 1H NMR (400 MHz, CDCl3)
d
7.50 (m, 2H),
d
7.41e7.39 (m, 2H), 7.31 (m, 3H), 7.25 (m, 2H); 13C NMR (100 MHz,
CDCl3)
134.2, 133.9, 133.6, 133.3, 130.8, 129.7, 129.6, 127.7; 77Se
NMR (76 MHz, CDCl3) 415.0.
d
d
5.1.37. (4-Bromophenyl)(phenyl)selane (37).10h Rf¼0.6 (hexane);
liquid; yield 0.27 g (86%). 1H NMR (400 MHz, CDCl3)
d 7.48e7.46 (m,
5.1.28. 1-(4-(Phenylselanyl)phenyl)ethanone (28).10l Rf¼0.3 (1:9,
2H), 7.38e7.36 (m, 2H), 7.31e7.28 (m, 5H); 13C NMR (100 MHz,
CDCl3)
134.3, 133.4, 132.4, 130.5, 130.4, 129.5, 127.8, 121.5; 77Se
NMR (76 MHz, CDCl3) 415.3.
ethyl acetate/hexane); white solid; yield 0.19 g (68%). 1H NMR
d
(400 MHz, CDCl3)
2.53 (s, 3H); 13C NMR (100 MHz, CDCl3)
130.3, 129.7, 128.9, 128.6, 128.5, 29.7 (grease), 26.5; 77Se NMR
(76 MHz, CDCl3) 428.2; HRMS (APCI) m/z 277.0142, calcd for
14H12OSeþH: 277.0127.
d
7.77 (d, J¼8.5 Hz. 2H), 7.57 (m, 2H), 7.33 (m, 5H),
d
d
197.3, 140.3, 135.2, 135.1,
5.1.38. (3-Nitrophenyl)(phenyl)selane (38).10h Rf¼0.3 (hexane); liq-
d
uid; yield 0.22 g (79%). 1H NMR (400 MHz, CDCl3)
d 8.18 (s, 1H),
C
8.03e8.01 (m, 1H), 7.63e7.56 (m, 3H), 7.39e7.35 (m, 4H); 13C NMR
(100 MHz, CDCl3) 148.6, 137.0, 134.8, 129.9, 129.8, 128.8, 128.5,
125.8, 123.5, 121.6; 77Se NMR (76 MHz, CDCl3)
434.
d
5.1.29. Phenyl(4-(trifluoromethyl)phenyl)selane
(29).10m Rf¼0.6
d
(hexane); liquid; yield 0.27 g (89%). 1H NMR (400 MHz, CDCl3)
d
7.60e7.57 (m, 2H), 7.45 (m, 4H), 7.38e7.33 (m, 3H); 13C NMR
5.1.39. 3-(Phenylselanyl)pyridine (39).5d Rf¼0.3 (9:1, hexane/ethyl
(100 MHz, CDCl3)
d
137.8, 134.9, 131.0, 129.8, 128.7, 128.5, 125.9 (q),
acetate); liquid; yield 0.15 g (63%). 1H NMR (400 MHz, CDCl3)
d 8.64
125.5, 122.8; 77Se NMR (76 MHz, CDCl3)
301.9819, calcd for C13H9F3Se: 301.9816.
d426.2; HRMS (APCI) m/z
(s, 1H), 8.46 (d, J¼3.7 Hz, 1H), 7.71 (dt, J¼8.0, 1.7 Hz, 1H), 7.48e7.46
(m, 2H), 7.28e7.26 (m, 3H), 7.18e7.15 (m, 1H); 13C NMR (100 MHz,

A. Kumar, S. Kumar / Tetrahedron 70 (2014) 1763e1772
1771
CDCl3)
d
152.6, 148.1, 140.2, 133.5, 129.6, 129.5, 128.9, 128.0, 124.3;
387.6.
NMR (400 MHz, CDCl3)
d
7.43 (m, 3H), 7.28 (dt, J¼8.3, 1.4 Hz, 1H),
77Se NMR (76 MHz, CDCl3)
d
7.11 (d, J¼8.3 Hz, 2H), 6.82e6.77 (m, 2H), 4.26 (br s, 2H); 13C NMR
(100 MHz, CDCl3)
d 149.1, 142.3, 137.8, 131.9, 127.5 (q), 125.7 (m),
5.1.40. 3-(Phenylselanyl)benzoic acid (40).13 Rf¼0.4 (8:2, hexane/
122.8, 119.0, 115.5, 112.4.
ethyl acetate); white solid; yield; 0.13 g (46%). 1H NMR (400 MHz,
CDCl3)
13C NMR (100 MHz, CDCl3)
130.0, 129.8, 128.7, 128.3, 127.1; 77Se NMR (76 MHz, CDCl3)
d
7.91 (d, J¼8.3 Hz, 2H), 7.60e7.58 (m, 2H), 7.38e7.35 (m, 5H);
171.7, 141.4, 137.9, 135.3, 131.6, 130.7,
430.7.
5.1.50. 2-((3-Chlorophenyl)thio)aniline (50).18 Rf¼0.60 (9.5:0.5
d
hexane/ethyl acetate); yellow liquid; yield 0.18 g (77%). 1H NMR
d
(400 MHz, CDCl3)
d
7.43 (dd, J¼7.7, 1.4 Hz, 1H), 7.27e7.23 (m, 1H),
7.12 (t, J¼7.6 Hz, 1H), 7.07e7.02 (m, 2H), 6.93 (dt, J¼7.8, 1.2 Hz, 1H),
5.1.41. Naphthalen-1-yl(phenyl)selane (41).10h Rf¼0.5 (hexane);
6.82e6.75 (m, 2H), 4.02 (br s, 2H); 13C NMR (100 MHz, CDCl3)
liquid; yield 0.23 g (82%). 1H NMR (400 MHz, CDCl3)
d
8.36e8.34 (m,
d 148.6, 139.1, 137.6, 134.9, 131.6, 129.9, 125.9, 125.5, 124.4, 119.1,
1H), 7.86e7.84 (m, 2H), 7.78 (dd, J¼7.1, 0.8 Hz, 1H), 7.54e7.49 (m,
115.7, 113.4.
2H), 7.40e7.35 (m, 3H), 7.20 (t, J¼3.5 Hz, 3H); 13C NMR (100 MHz,
CDCl3)
d
134.2, 134.1, 133.9, 131.8, 131.7, 129.4, 129.3, 129.2, 128.6,
5.1.51. (4-Bromophenyl)(4-methoxyphenyl)sulfane (51).10h Rf¼0.4
127.7, 127.0, 126.8, 126.4, 126.0; 77Se NMR (76 MHz, CDCl3)
d
354.2.
(9.5:0.5 hexane/ethyl acetate); white solid; yield 0.19 g (66%). 1H
NMR (400 MHz, CDCl3)
d
7.39 (d, J¼8.9 Hz, 2H), 7.31 (d, J¼8.5 Hz,
5.1.42. 4-(Phenylselanyl)phenol (42).10m Rf¼0.4 (1:9, ethyl acetate/
2H), 6.99 (d, J¼8.5 Hz, 2H), 6.89 (d, J¼8.9 Hz, 2H), 3.81 (s, 3H); 13C
hexane); white solid; yield 0.15 g (61%). 1H NMR (400 MHz, CDCl3)
NMR (100 MHz, CDCl3)
119.4, 115.2, 55.4.
d 160.1, 138.2, 135.6, 131.9, 129.4, 123.5,
d
7.45 (d, J¼8.6 Hz, 2H), 7.34e7.31 (m, 2H), 7.23e7.17 (m, 3H), 6.78
(d, J¼8.6 Hz, 2H), 5.15 (br s, 1H); 13C NMR (100 MHz, CDCl3)
d 155.8,
136.7, 133.1, 131.0, 129.2, 126.5, 120.1, 116.6; 77Se NMR (76 MHz,
5.2. General method for the synthesis of symmetrical diaryl
selenides
CDCl3)
d 401.1.
5.1.43. 2-(Phenylthio)aniline (43).16 Rf¼0.60 (9.5:0.5 hexane/ethyl
In a 10 mL capacity round bottom flask Se-powder (80 mg,
1.0 mmol) and sodium borohydride (38 mg, 1.0 mmol) were added
in ethanol (3 mL). Reaction mixture was stirred at room tempera-
ture for 1 h under nitrogen atmosphere. Then, CuSO4$5H2O
(0.1 mmol, 25 mg), 1,10-phenanthroline (0.1 mmol, 18 mg), and
phenylboronic acid (121 mg, 1.0 mmol) were added sequentially.
Reaction mixture was stirred under oxygen balloon for 10 h.
Progress of reaction was monitored by TLC. Then, reaction mixture
was poured into water (25 mL) and extracted with ethyl acetate
(3ꢂ20 mL). Combined organic layer was dried over (Na2SO4),
evaporated under reduced pressure at 40 ꢀC. Crude mixture was
purified by column chromatography (hexane) to provide diphe-
nylselenide 22, as a yellow liquid; yield: 217 mg (93%). Similar
procedure was followed for the synthesis of compounds listed in
Table 5. All the products are characterized by 1H, 13C, and 77Se NMR.
The spectroscopic data presented below.
acetate); greenish liquid; yield 0.16 g (82%). 1H NMR (400 MHz,
CDCl3)
(m, 3H), 6.81e6.74 (m, 2H). 4.12 (br s, 2H); 13C NMR (100 MHz, CDCl3)
148.4, 137.4, 136.7, 131.1, 129.0, 126.6, 125.5, 119.0, 115.6, 114.8.
d
7.45 (dd, J¼7.6, 1.3 Hz, 1H), 7.21 (t, J¼7.6 Hz, 3H), 7.12e7.07
d
5.1.44. 2-((4-Fluorophenyl)thio)aniline (44).16 Rf¼0.60 (9.5:0.5
hexane/ethyl acetate); greenish liquid; yield 0.15 g (71%), 1H NMR
(400 MHz, CDCl3)
7.09e7.05 (m, 2H), 9.92 (t, J¼8.7 Hz, 2H), 6.78e6.72 (m, 2H), 3.94 (br
s, 2H); 13C NMR (100 MHz, CDCl3)
162.5, 160.0, 148.6, 137.1, 131.7
d
7.42 (dd, J¼7.7, 1.4 Hz, 1H), 7.21 (m, 1H),
d
(d), 131.1, 128.7 (d), 118.8, 116.2, 116.0, 115.4, 115.0.
5.1.45. 2-((4-Bromophenyl)thio)aniline (45).16 Rf¼0.60 (9.5:0.5
hexane/ethyl acetate); greenish liquid; yield 0.20 g (73%). 1H NMR
(400 MHz, CDCl3)
d
7.42 (dd, J¼7.7,1.4 Hz,1H), 7.30 (d, J¼8.7 Hz, 2H),
7.25e7.21 (m, 1H), 6.93 (d, J¼8.7 Hz, 2H), 6.82e6.74 (m, 2H), 3.97
(br s, 2H); 13C NMR (100 MHz, CDCl3)
131.4, 128.1, 119.2, 119.1, 115.7, 114.2.
d
148.3, 137.4, 136.1, 132.0,
5.2.1. Di-p-tolylselane (52).11 Rf¼0.6 (hexane); liquid; yield 0.21 g
(82%). 1H NMR (400 MHz, CDCl3)
d
7.35 (d, J¼8.1 Hz, 4H), 7.07
(d, J¼8.1 Hz, 4H), 2.31 (s, 6H), 13C NMR (100 MHz, CDCl3)
d 137.2,
5.1.46. 2-(p-Tolylthio)aniline (46).16 Rf¼0.60 (9.5:0.5 hexane/ethyl
133.0, 130.1, 127.8, 21.1. 77Se NMR (76 MHz, CDCl3)
d 399.8; HRMS
acetate); liquid; yield 0.18 g (86%). 1H NMR (400 MHz, CDCl3)
d
7.43
(APCI) m/z 262.0267, calcd for C14H14Se: 262.0256.
(dd, J¼7.7, 1.4 Hz, 1H), 7.21 (dt, J¼7.3, 1.4 Hz, 1H), 7.05e7.00 (m, 4H),
6.79e6.73 (m, 2H), 3.94 (br s, 2H). 2.27 (s, 3H); 13C NMR (100 MHz,
5.2.2. Bis(4-(trifluoromethyl)phenyl)selane (53).11 Rf¼0.6 (hexane);
CDCl3)
115.5.
d
148.3, 137.0, 135.5, 133.0, 130.8, 129.8, 127.2, 118.9, 115.6,
liquid; yield 0.22 g (61%). 1H NMR (400 MHz, CDCl3)
d 7.54 (m, 8H);
13C NMR (100 MHz, CDCl3)
d
135.1, 133.1, 130.2, 126.3 (q), 125.2; 77Se
NMR (76 MHz, CDCl3) 431.7.
d
5.1.47. 2-(o-Tolylthio)aniline (47).16 Rf¼0.50 (9.5:0.5 hexane/ethyl
acetate); solid; yield 0.17 g (80%). 1H NMR (400 MHz, CDCl3)
d
7.42
5.2.3. 4,40-Selenodibenzonitrile (54).15 Rf¼0.3 (1:9, ethyl acetate/
(dd, J¼7.7, 1.3 Hz, 1H), 7.25 (m, 1H), 7.17 (m, 1H), 7.05 (m, 2H), 6.78
hexane); white solid; yield 0.20 g (72%). 1H NMR (400 MHz, CDCl3)
(m, 3H), 4.08 (br s, 2H); 13C NMR (100 MHz, CDCl3)
d
148.7, 137.3,
d
7.53 (q, J¼8.7 Hz, 8H); 13C NMR (100 MHz, CDCl3)
d 136.7, 133.2,
135.7, 135.4, 130.9, 130.2, 126.6, 125.6, 125.3, 119.0, 115.4, 114.2, 20.0.
132.9, 118.2, 111.7; 77Se NMR (76 MHz, CDCl3)
d 451.1; HRMS (APCI)
m/z 284.9936, calcd for C14H8N2SeþH: 284.9926.
5.1.48. 2-(Naphthalen-2-ylthio)aniline (48).17 Rf¼0.50 (9.5:0.5 hex-
ane/ethyl acetate); liquid; yield 0.20 g (79%). 1H NMR (400 MHz,
5.2.4. Di-m-tolylselane (55).11 Rf¼0.5 (hexane); liquid; yield 0.22 g
CDCl3)
d
7.73 (d, J¼7.7 Hz, 1H), 7.68 (d, J¼8.6 Hz, 1H), 7.62
(83%). 1H NMR (400 MHz, CDCl3)
d
7.31 (s, 2H), 7.25 (d, J¼7.7 Hz,
(d, J¼7.7 Hz, 1H), 7.49e7.48 (m, 2H), 7.42e7.35 (m, 2H), 7.27e7.22
2H), 7.15 (t, J¼7.7 Hz, 2H), 7.06 (d, J¼7.7 Hz, 2H), 2.30 (s, 6H); 13C
(m, 2H), 6.84 (d, J¼7.9 Hz, 1H), 6.80 (t, J¼7.5 Hz, 1H), 3.58 (br s, 2H);
NMR (100 MHz, CDCl3) d 139.1, 133.6, 130.9, 130.0, 129.1, 128.1, 21.3;
13C NMR (100 MHz, CDCl3)
d
148.0, 137.3, 134.1, 133.8, 131.6, 131.1,
77Se NMR (76 MHz, CDCl3)
d 412.6.
128.7, 127.7, 127.0, 126.5, 125.5, 125.3, 124.7, 119.3, 115.9, 115.2.
5.2.5. Bis(3-chlorophenyl)selane (56).15 Rf¼0.5 (hexane); liquid;
5.1.49. 2-((4-(Trifluoromethyl)phenyl)thio)aniline
(49).18 Rf¼0.60
yield 0.21 g (69%). 1H NMR (400 MHz, CDCl3)
d
7.48 (t, J¼1.7 Hz, 2H),
(9.5:0.5 hexane/ethyl acetate); greenish solid; yield 0.19 g (71%). 1H
7.37 (t, J¼1.3 Hz, 1H), 7.36 (t, J¼1.3 Hz, 1H), 7.31e7.28 (m, 2H),

1772
A. Kumar, S. Kumar / Tetrahedron 70 (2014) 1763e1772
7.26e7.22 (m, 2H); 13C NMR (100 MHz, CDCl3)
d
135.1, 132.7, 132.0,
d 435.7; HRMS (APCI)
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131.1, 130.5, 130.0; 77Se NMR (76 MHz, CDCl3)
m/z 301.9161, calcd for C12H8Cl2Se: 301.9158.
5.2.6. Di(naphthalen-1-yl)selane (57).11 Rf¼0.4 (hexane); yellow
solid; yield 0.25 g (76%). 1H NMR (400 MHz, CDCl3)
d 8.38e8.35 (m,
2H), 7.88e7.86 (m, 2H), 7.80 (d, J¼8.0 Hz, 2H), 7.55e7.50 (m, 6H),
7.28 (t, J¼7.4 Hz, 2H); 13C NMR (100 MHz, CDCl3)
d 134.2, 133.7,
132.2, 129.9, 128.7, 128.5, 127.1, 126.9, 126.4, 126.1; 77Se NMR
(76 MHz, CDCl3)
d 305.1.
5.2.7. Di(benzofuran-2-yl)selane (58). Rf¼0.4 (1:9, ethyl acetate/
hexane); white sold; yield 0.18 g (59%). 1H NMR (400 MHz, CDCl3)
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7.52 (d, J¼7.4 Hz, 2H), 7.46 (d, J¼7.4 Hz, 2H), 7.26 (m, 2H), 7.20 (m,
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Supplementary data
Supplementary data associated with this article can be found in
the online version, at http://dx.doi.org/10.1016/j.tet.2014.01.030.
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