Synthesis of unsymmetrical diorganyl chalcogenides under greener conditions: Use of an iodine/DMSO system, solvent- and metal-free approach

Article abstract of DOI:10.1002/adsc.201500024

Herein, we report a greener iodine-catalyzed protocol to access different types of unsymmetrical diorganyl chalcogenides. This new approach works in the absence of solvent and metal. The desired products were obtained in good to excellent yields using one equivalent of arylboronic acids, half an equivalent of various diorganyl dichalcogenides, iodine (10 mol%) as a catalyst and 2 equivalents of dimethyl sulfoxide (DMSO; as oxidant), with a reaction time of 10 min under microwave irradiation.

Full text of DOI:10.1002/adsc.201500024

FULL PAPERS
DOI: 10.1002/adsc.201500024
Synthesis of Unsymmetrical Diorganyl Chalcogenides under
Greener Conditions: Use of an Iodine/DMSO System, Solvent-
and Metal-Free Approach
Sumbal Saba,a Jamal Rafique,a and Antonio L. Bragaa,*
a
Departamento de Quꢀmica, Universidade Federal de Santa Catarina, Florianopolis 88040-900, SC – Brazil
Fax : (+55)-48-3721-6427; phone: (+55)-48-3721-6427; e-mail: braga.antonio@ufsc.br
Received: January 13, 2015; Revised: February 19, 2015; Published online: && &&, 0000
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201500024.
Abstract: Herein, we report a greener iodine-cata- iodine (10 mol%) as a catalyst and 2 equivalents of
lyzed protocol to access different types of unsymmet- dimethyl sulfoxide (DMSO; as oxidant), with a reac-
rical diorganyl chalcogenides. This new approach tion time of 10 min under microwave irradiation.
works in the absence of solvent and metal. The de-
sired products were obtained in good to excellent Keywords: boronic acids; iodine; metal-free condi-
yields using one equivalent of arylboronic acids, half tions; microwave irradiation; selenides; sulfides; tel-
an equivalent of various diorganyl dichalcogenides, lurides
Introduction
ligands and catalysts, precious and rare metals, reduc-
ing agents, stoichiometric or greater amounts of re-
Unsymmetrical organochalcogenides (S, Se, and Te) agents, long reaction times, harsh reaction conditions
have become an attractive synthetic target in the past and oxygen-free techniques. Also, there are only
few decades and they have been extensively reported a few general methods available which are applicable
in various research articles,[1] reviews[2] and books.[3] to the synthesis of S-, Se- and Te-based unsymmetrical
In recent years these compounds have been employed diaryl chalcogenides as well as alkyl aryl chalcoge-
in certain reactions[4] as catalysts,[5a,b] ligands,[5c] ionic nides.[18]
liquids[6] and synthetic intermediates in total synthe-
Similarly, different methods have been developed
sis[2,3,7] besides being applied in asymmetric cataly- for the synthesis of unsymmetrical chalcogenides
sis.[4a] Moreover, synthetic organochalcogen com- using direct C H functionalization/activation. This
[19]
À
pounds have been found to function as antioxidant, strategy is important, since it eliminates an unnecessa-
anticanACHTUNGTRENNUNG
cer, antihypertensive and antiviral agents.[2d,e,3,8] ry step, directly accessing the desired product. How-
They also have important applications in materials ever, in most cases the use of a solvent, a transition
science.[9]
metal catalyst and additives is required.
Similarly, organoboronic acids and their derivatives
In the last few years, the I2/DMSO system has been
are easily accessible, stable and are compatible with applied in various greener organic transformations.[20]
several functional groups. Due to these properties However, to date, to the best of our knowledge, there
they have been used as coupling partners in different have been no reports involving the application of this
organic transformations.[10]
catalytic oxidant system to the preparation of organo-
Considering the importance of unsymmetrical orga- tellurim compounds. In addition, the preparation of
nochalcogenides, several methods have been devel- organochalcogen compounds through the reaction of
oped for their synthesis.[11] Among them, metal-cata- organoboronic acids and diorganodichalcogenides
lyzed aryl-chalcogen bond formation is one of the using this system has not been explored. Recently, we
most commonly used protocols,[2a–c,11] which generally successfully explored the selenylation and thiolation
involves the presence of a ligand. Several metal sour- of indoles catalyzed by the iodine/DMSO system,
ces, such as Pd,[12] Ni,[13] Cu,[14] Zn,[15] Fe[16] and In,[17] avoiding the use of solvents and metals, in an open at-
have been used. However, these types of transforma- mosphere.[21]
tions have their own particular drawbacks, such as the
In this context, it would be advantageous and
use of environmentally unfriendly solvents, expensive highly desirable to develop a ligand-free and metal-
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1
ÞÞ
These are not the final page numbers!

FULL PAPERS
Sumbal Saba et al.
Table 1. Optimization of the microwave parameters.[a]
Scheme 1. Iodine-catalyzed synthesis of unsymmetrical orga-
nochalcogenides under ligand-, metal- and solvent-free con-
ditions.
Entry
MW [W]
T [8C]
t [min]
Yield [%][b]
free protocol involving a solvent-free system which
works in shorter reaction times for the preparation of
unsymmetrical diorganochalcogenides. As part of our
wider research program aimed at designing and devel-
oping eco-friendly processes,[21,22] herein we report,
for the first time, the use of the I2/DMSO system in
the synthesis of unsymmetrical organochalcogenides,
applicable to Te, Se and S, under microwave irradia-
tion. This novel approach worked smoothly with half
an equivalent of different dichalcogenides without the
need for a ligand, metal or solvent, in a very short re-
action time (Scheme 1).
1
2
3
4
5
6
7
8
100
100
100
100
100
100
100
80
100
100
100
100
100
80
120
100
100
100
1
3
5
10
15
10
10
10
10
18 h
49
77
84
94
96
84
95
80
85
69
9
120
10[c]
[a]
Reaction conditions: 1a (0.125 mmol), 2a (2 equiv.), I2
(5 mol%), DMSO (2 equiv.) under MW irradiation.
Isolated yield.
[b]
[c]
Conventional heating in sealed tube.
Results and Discussion
Table 2. Optimization of the reaction conditions.[a]
To identify the best reaction conditions, diphenyl di-
telluride 1a and 4-methoxyphenylboronic acid 2a
were used as standard substrates, a stoichiometric
amount of oxidant was employed and I2 was used as
a catalyst under microwave irradiation (Table 1 and
Table 2). Firstly, the reaction time and microwave pa-
rameters were evaluated for this coupling reaction
(Table 1). We commenced our studies by varying the
reaction time (entries 1–5). On performing the reac-
tion for 1 min we observed the formation of the de- Entry
I2 [mol%]
Oxidant [equiv.]
Yield [%][b]
sired product 3a in only 49% yield (entry 1). Incre-
mental increases in the reaction time resulted in a sig-
nificant improvement in the yield of 3a.
1
2
3
4
–
1
5
10
15
–
DMSO (2)
DMSO (2)
DMSO (2)
DMSO (2)
DMSO (2)
DMSO (2)
DMSO (2)
–
DMSO (1)
DMSO (3)
TBHP (2)
H2O2 (2)
traces
48
86
94
96
60
84
20
69
The best result was achieved after 10 min at 1008C
with 100 W of power, where the product 3a was ac-
cessed in 94% yield (entry 4). No substantial change
in the yield was observed on applying a 15 min reac-
tion time (entry 5).
In the next step, the temperature was screened and
the ideal conditions were observed at 1008C; lower
temperatures afforded lower yields of 3a (entry 6 vs.
4) and higher temperature did not show a strong in-
fluence (entry 7 vs. 4). The reaction was also carried
out under different levels of MW irradiation power.
Both lower power (80 W; entry 8) and higher power
(entry 9) had a negative effect on the isolated yield of
3a.
5
6[c]
7[d]
8
–
10
10
10
10
10
9
10
11
12
95
47
70
[a]
Reaction conditions: 1a (0.125 mmol), 2a (2 equiv.) in the
presence of catalyst (10 mol%) and oxidant (2 equiv.) for
10 min at 1008C and 100 W of MW irradiation.
Isolated yields.
Reaction performed using 10 mol% of NaI.
Reaction performed using 10 mol% of HI.
[b]
[c]
[d]
In order to compare and evaluate the influence of
the conventional heating methodology, the reaction
was also performed in an oil bath heating system a lower yield, highlighting the superiority of the MW
(entry 10). A longer reaction time (18 h) gave 3a in method.
2
asc.wiley-vch.de
ꢁ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 0000, 000, 0 – 0
ÝÝ
These are not the final page numbers!

FULL PAPERS
Synthesis of Unsymmetrical Diorganyl Chalcogenides
Table 3. Synthesis of unsymmetrical diorganyl tellurides.[a,b]
In the next step, the effects of the catalyst loading
and the stoichiometric oxidant on the reaction system
were screened (Table 2). In the absence of iodine, the
reaction afforded only trace amounts of 3a (entry 1).
With the use of 1 mol% of iodine (entry 2) 3a was ob-
tained in 48% yield. Increasing the catalyst loading to
5 mol% caused the yield to increase to 86% (entry 3),
which was further improved to 94% when 10 mol%
of I2 was used (entry 4). Further increases in the cata-
lyst loading did not appear to have any effect on the
isolated yield (entry 5). Subsequently, using NaI
(entry 6) instead of I2 resulted in 3a with 60% yield
while using HI (entry 7) afforded coupled products
with 84% yield, indicating that HI is probably one of
the intermediates of this transformation.
After ascertaining the best options for the catalyst
and its loading, the effects of the quantity and type of
oxidant used were evaluated. 3a was obtained in poor
yield when the reaction was performed in the absence
of DMSO (entry 8), while 1 equiv. of DMSO afforded
the desired product in 69% yield (entry 9). It should
be noted that increasing the stoichiometric amount of
DMSO to 3 equiv. did not affect the yield of 3a
(entry 10 vs. 4). Other oxidants were also screened,
but they failed to provide a more favorable outcome
(entries 11 and 12).
After determining the best reaction parameters, we
explored the efficiency and generality of our method-
ology by applying it to various diorganyl ditellurides
1 and arylboronic acids 2 under the optimized condi-
tions (Table 3).
[a]
Reaction conditions: 1 (0.25 mmol), 2 (0.5 mmol) in the
presence of I2 (10 mol%) and DMSO (2 equiv.) for
The reaction worked well for structurally different
organic moieties containing both electron-withdraw-
ing (R1, R2 =Cl, CF3, NO2, COR, etc.) and electron-
10 min at 1008C and 100 W MW irradiation.
Isolated yields.
[b]
donating (R1, R2 =Me, OMe, NH2, etc.) groups as furnished the corresponding products 3s–t in very
well as bulky groups. Firstly, we used different aryl- good yields.
boronic acids 2 while keeping diphenyl ditelluride 1a
The success in the iodine-catalyzed synthesis of un-
constant, resulting in 3a–j in good to excellent yields. symmetrical diorganyl tellurides 3 by intermolecular
À
In general, substrates 2 with electron-donating groups C Te bond formation using diorganyl ditellurides
at the aryl ring afforded good results. The steric hin- 1 and arylboronic acids 2, prompted us to expand this
drance of ortho-substituted aryl substrates did not methodology to diorganyl diselenide 4 as a way to
appear to influence the yields of 3h–i. Similarly, the access unsymmetrical diorganyl selenides 6 (Table 4).
presence of a bulky substrate (R=2-naphthyl) result- In order to evaluate the electronic and steric effects,
ed in the desired product 3g in 93% yield. We were initially, we varied the substituents at the aryl ring of
also delighted to find that a heteroarylboronic acid af- boronic acid 2, furnishing the corresponding selenides
forded the desired product 3j with 90% yield.
6a–h, as shown in Table 4. Electronic effects due to
Subsequently, we successfully used electron-donat- the para and meta substituents on 2 exerted a limited
ing and electron-withdrawing substituents in the para- influence, affording the corresponding product 6a–d
position of the aryl ring of 1 and checked the elec- and 6g in 86–93% yields The reaction seems not to be
tronic as well as the steric effects of 2. The desired sensitive to steric effects at the ortho position (R=
products 3k–r were obtained in good to excellent Me, OMe) or bulky groups (R=naphthyl) on the aryl
yields, the substituents showing no significant negative ring of 2, furnishing the desired products 6e, 6f and
influence. Aliphatic dichalcogenides are generally 6h in 91–93% yields. Similarly, substrates 4 with sub-
considered to be less reactive, giving low yields, due stituents at the aryl ring of the diselenide afforded the
to the b-chalcogen oxide elimination.[17b] Gratifyingly, corresponding products 6i–k in 88–92% yields, show-
under our optimized conditions, dibutyl ditelluride ing no significant influence of the electronic or steric
effects on the diselenides 4. Subsequently, we success-
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
3
ÞÞ
These are not the final page numbers!

FULL PAPERS
Sumbal Saba et al.
Table 4. Synthesis of unsymmetrical diorganyl selenides and
sulfides.[a,b]
Scheme 2. Iodine-catalyzed reactions of the potassium salt
of vinyltrifluoroborate 8 with diorganyl dichalcogenide.
Figure 1. Results for the reaction at different scales.
[a]
telluride 1a and boronic acid 2a were selected as the
test materials, affording 3a with a slight decrease in
the yield. Therefore, this method could be used as
a practical way to synthesize unsymmetrical diorganyl
chalcogenides on a larger scale.
Reaction conditions: 4 or 5 (0.25 mmol), 2 (0.5 mmol) in
the presence of I2 (10 mol%) and DMSO (2 equiv.) for
10 min at 1008C and 100 W MW irradiation.
Isolated yields.
[b]
fully carried out the reaction between aliphatic disele-
Considering that little is known about the coupling
nide and 2a, affording n-butyl (4-methoxyphenyl) sel- reaction of diorganyl chalcogenides and organoboron-
enide 6l with 83% yield. ic acids under metal-free conditions, control experi-
The scope of the reaction regarding the preparation ments were conducted in order to elucidate the mech-
of unsymmetrical diorganyl sulfides was then ex- anism. Firstly, the addition of a radical inhibitor
plored by using different disulfides 5a–c under the op- (TEMPO) under the standard reaction conditions did
timal reaction conditions (Table 2, entry 4). Interest- not hamper the reaction and 3a was obtained in 86%
ingly, the reaction of different diaryl disulfides 5a– yield [Scheme 3, Eq. (1)], which excluded the possibil-
c with 4-methoxyphenylboronic acid 2a proceeded ity of a radical pathway. This result indicates that,
smoothly and afforded the corresponding products most probably, a radical mechanism is not operating
7a–c in 75–84% isolated yields (Table 4). The small and the PhY radical species is not involved. Secondly,
decrease in the yields can probably be explained by when boronic acid 2a was treated with PhSeBr in-
À
the stronger S S bond of the diaryl disulfides com- stead of diphenyl diselenide 4a, the product 6a was
pared to the respective ditellurides 1 or diselendies 4. isolated with 87% yield [Scheme 3, Eq. (2)], demon-
In order to further investigate the scope of this new strating that the reaction passes through a phenylsele-
coupling methodology, we extended our study to po- nium cation species.
tassium vinyltrifluoroborate 8 as an alternative to bor-
Based on the above experiments and on previous
onic acid in these tellurylation and selenylation reac- reports,[23,24] a plausible reaction pathway for the syn-
tions (Scheme 2), applying the optimal reaction condi- thesis of the unsymmetrical diorganyl chalcogenides
tions (Table 2, entry 4). Interestingly, the reaction of under metal-free conditions is proposed in Scheme 4.
ditelluride and diselenide with 8 proceeded smoothly Firstly, RYI (Y=Te, Se, S) would be generated
and afforded the corresponding coupled product 9a through the reaction of diorganyl dichalcogenide
and 9b in 87% and 89% isolated yields (Scheme 2).
RYYR with the catalyst (I2). Subsequently, the reac-
To demonstrate the synthetic utility of this new tive RYI intermediate on reaction with organoboronic
coupling protocol, a series of reactions was carried acid would generate species a which on migration of
out on different scales (Figure 1; up to 10 mmol). Di- the aryl moiety from boron to chalcogen and elimina-
4
asc.wiley-vch.de
ꢁ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 0000, 000, 0 – 0
ÝÝ
These are not the final page numbers!

FULL PAPERS
Synthesis of Unsymmetrical Diorganyl Chalcogenides
Scheme 3. Investigation of the mechanism.
yields in the presence of 10 mol% of iodine, one
equiv. of arylboronic acids, half an equiv. of various
diorganyl dichalcogenides and 2 equiv. of DMSO (as
an oxidant). Also, the reaction was performed without
the exclusion of air and moisture at 1008C for 10 min
under microwave irradiation. Various substituents
with different electronic and steric effects were toler-
ated in the optimized reaction conditions. The reac-
tion was shown to be robust and could easily be
scaled-up without any significant loss of yield.
The chemistry described herein represents an alter-
native and eco-friendly synthetic approach for the
preparation of unsymmetrical diorganyl chalcoge-
nides.
Experimental Section
General Procedure for the Iodine-Catalyzed
Synthesis of Unsymmetrical Organochalcogenides
Scheme 4. Plausible reaction pathway.
A mixture of the appropriate arylboronic acid (0.5 mmol),
diorganyl dichalcogenide (0.25 mmol), iodine (10 mol%,
tion of iodide could result in species b. The deborona- 12 mg) and 2 equiv. of DMSO (1 mmol, 78 mg) were placed
in a microwave glass tube, which was sealed and placed in
a CEM Discover microwave device. A maximum irradiation
power of 100 W and a temperature of 1008C were applied
for 10 min. When the reaction was completed, the reaction
mixture was dissolved in ethyl acetate (15 mL) and washed
with 2ꢂ10 mL of an aqueous solution of 10% Na2S2O4. The
organic phase was separated, dried over MgSO4 and concen-
trated under vacuum. The crude product was purified by
flash chromatography on silica gel using hexane or a mixture
of hexane/ethyl acetate (99:1) as the eluent.
3-(Phenyltellanyl)aniline (3e): Yield: 0.132 g (89%);
yellow oil; 1H NMR (200 MHz, CDCl3): d=7.57 (d, J=
8.2 Hz, 2H), 7.25–6.92 (m, 6H), 6.60–6.55 (m, 1H), 3.61 (s,
2H); 13C NMR (50 MHz, CDCl3): d=147.3, 139.1, 134.2,
130.3, 129.7, 128.2, 124.4, 115.0, 112.5; IR (KBr): n=3300,
3250, 3032, 2926, 1629, 1725, 1501, 1460,1097, 1013, 919, 821,
728 cmÀ1; HR-MS: m/z=300.0027, calcd. for C12H12NTe
[M+H]+: 300.0027.
tion of species b would furnish the desired product
RYAr with the simultaneous formation of HI. In the
next step of the mechanism, two equivalents of HI on
reaction with DMSO would then regenerate iodine,[24]
through the protonated sulfur species c. This species
would be rapidly converted to the iodine-dimethyl
sulfide adduct d with the elimination of water. Finally,
the cycle would be completed by the conversion of
the iododimethylsulfonium iodide species d to di-
methyl sulfide with the regeneration of the catalyst in
the reaction medium.
Conclusions
In conclusion, we have developed a greener iodine-
catalyzed, metal-free and solvent-free method for the
synthesis of a variety of unsymmetrical diorganyl
chalcogenides under microwave irradiation. The de-
Phenyl[3-(trifluoromethyl)phenyl]tellane (3f): Yield:
1
0.138 g (79%); yellow oil; H NMR (200 MHz, CDCl3): d=
7.99–7.68 (m, 4H), 7.57–7.47 (m, 1H), 7.37–7.18 (m, 4H);
sired products were obtained in good to excellent 13C NMR (50 MHz, CDCl3): d=140.5 (q,
J
C,F =1.5 Hz),
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
5
ÞÞ
These are not the final page numbers!

FULL PAPERS
Sumbal Saba et al.
138.9, 138.1, 133.7 (q, JC,F =4 Hz), 131.6 (q, JC,F =32 Hz),
129.9, 129.6, 128.6, 124.5 (q, JC,F =4), 123.7 (q, JC,F =271),
115.9, 113.8; IR (KBr); n=3065, 3012, 2993, 2923, 1572,
1474, 1417, 1270, 1081, 1017, 997, 793, 695 cmÀ1; HR-MS:
m/z=351.9716, calcd. for C13H9F3Te [M]+: 351.9714.
7.22 (m, 3H); 13C NMR (50 MHz, CDCl3): d=148.6, 142.5,
140.8, 135.7, 131.3, 130.4, 130.1, 122.8,116.5, 110.8; IR
(KBr): n=3096, 2924, 2849, 1597, 1562, 1468, 1415, 1342,
1268, 1056, 966, 874, 832, 726, 662 cmÀ1; HR-MS: m/z=
362.92899, calcd. for C12H8ClNO2Te [M]+: 362.92900.
[4-Chlorophenyl)(ortho-tolyl)tellane (3r): Yield: 0.145 g
2-(Phenyltellanyl)thiophene (3j): Yield: 0.129 g (90%);
1
1
(88%); white oil; H NMR (200 MHz, CDCl3): d=7.56 (d,
yellow solid; mp 36–388C; H NMR (200 MHz, CDCl3): d=
J=8.4 Hz, 2H), 7.48 (d, J=7.5 Hz, 1H),7.24–7.20 (m, 2H),
7.16 (d, J=8.4 Hz, 2H), 6.99–6.91(m, 1H), 2.39(s, 3H);
13C NMR (50 MHz, CDCl3): d=142.1, 139.8, 137.8, 134.6,
129.9, 129.6, 128.5, 127.0, 118.9, 111.8, 26.2; IR (KBr): n=
3055, 3002, 2967, 2922, 1652, 1558, 1470, 1458, 1378, 1089,
1007, 809, 744, 668 cmÀ1; HR-MS: m/z=331.9593, calcd. for
C13H11ClTe[M]+: 331.9596.
7.58–7.48 (m, 4H), 7.25–7.14 (m, 3H), 7.01–6.97 (m, 1H);
13C NMR (50 MHz, CDCl3): d=142.2, 138.1, 135.7, 135.2,
129.5, 129.3, 127.6, 116.6; IR (KBr): n=3112, 3069, 2996,
2926, 1876, 1796, 1658, 1564,1462, 1333, 1214, 1070, 1023,
921, 836, 719, 708 cmÀ1; HR-MS: m/z=289.9403, calcd. for
C10H8STe [M]+: 289.9401.
3-[(4-Methoxyphenyl)tellanyl]aniline (3k): Yield: 0.137 g
(84%); brown solid; mp 97–998C; 1H NMR (200 MHz,
CDCl3): d=7.72 (d, J=8.8 Hz, 2H), 6.94 (d, J=4.8 Hz, 2H),
6.90–6.85 (m, 1H) 6.79 (d, J=8.8 Hz, 2H), 6.57–6.47 (m,
1H), 3.79 (s, 3H), 3.56 (s, 2H); 13C NMR (50 MHz, CDCl3):
d=160.0, 147.2, 141.2, 130.0, 126.5, 122.7, 116.7, 115.6, 114.3,
103.3, 55.2; IR (KBr): n=3472, 3379, 3030, 2962, 2839, 1563,
1487, 1326, 1248, 1099, 987, 815, 774 cmÀ1; HR-MS: m/z=
329.0051, calcd. for C13H13NOTe [M]+: 329.0054.
(4-Chlorophenyl)(ortho-tolyl)selane (6j): Yield: 0.125 g
1
(89%); white oil; H NMR (200 MHz, CDCl3): d=7.35–7.01
(m, 8H), 2.37(s, 3H); 13C NMR (50 MHz, CDCl3): d=
140.1,134.1, 133.8, 133.3, 131.2, 130.5, 129.6, 129.3, 128.2,
126.9, 22.5; IR (KBr): n=3059, 3008, 2969, 1652, 1558, 1472,
1386, 1274, 1089, 1009, 811, 746, 668 cmÀ1; HR-MS: m/z=
281.9707, calcd. for C13H11ClSe [M]+: 281.9707.
(2-Methoxyphenyl)(4-methoxyphenyl)selane (6k): Yield:
1
0.134 g (92%); white oil; H NMR (400 MHz, CDCl3): d=
1-{4-[(4-Methoxyphenyl)tellanyl]phenyl}ethan-1-one (3l):
Yield: 0.164 g (93%); yellow liquid; 1H NMR (200 MHz,
CDCl3): d=7.79 (d, J=8.8 Hz, 2H), 7.69 (d, J=8.5 Hz, 2H),
7.49 (d, J=8.5 Hz, 2H), 6.84 (d, J=8.8 Hz, 2H), 3.83 (s,
3H), 2.53 (s, 3H); 13C NMR (50 MHz, CDCl3): d=197.7,
160.6, 142.4, 135.7, 134.6, 128.7, 125.6, 115.9, 102.2, 55.3,
26.5 cmÀ1; IR (KBr): n=3002, 2959, 2926, 2837, 1682, 1635,
1582, 1488, 1388, 1246, 1176, 1025, 954, 815, 742 cmÀ1; HR-
MS: m/z=356.0057, calcd. for C15H14O2Te [M]+: 356.0051.
(3-Nitrophenyl)(para-tolyl]tellane (3n): Yield: 0.148 g
7.57 (d, J=8.7 Hz, 2H), 7.15–7.10 (m, 1H), 6.90 (d, J=
8.7 Hz, 2H), 6.83–6.70 (m, 3H), 3.89 (s, 3H), 3.82 (s, 3H);
13C NMR (100 MHz, CDCl3): d=160.2, 155.9, 138.5, 129.0,
126.9, 123.6, 121.6, 117.3, 115.3, 110.1, 55.8, 55.3; IR (KBr):
n=3064, 2961, 2935, 1843, 1792, 1699, 1652, 1558, 1456,
1397, 1240, 1027, 824, 748, 668 cmÀ1 77Se NMR (CDCl3): d=
;
349.09; HR-MS: m/z=294.0150, calcd. for C14H14O2Se [M]+:
294.0154.
(3-Chlorophenyl)(4-methoxyphenyl)sulfane (7c): Yield:
1
1
94 mg (75%); white solid; mp 59–618C; H NMR (400 MHz,
(87%); yellow oil; H NMR (200 MHz, CDCl3): d=8.36 (s,
CDCl3): d=7.43 (d, J=8.9 Hz, 2H), 7.14–7.04 (m, 3H),
7.00–6.98 (m, 1H), 6.92 (d, J=8.9 Hz, 2H), 3.82 (s, 3H);
13C NMR (50 MHz, CDCl3): d=160.4, 141.4, 136.2, 134.9,
129.9, 127.1, 125.7, 125.6, 122.8, 115.3, 55.5; IR (KBr): n=
3083, 3016, 2963, 2937, 2894, 2837, 2045, 1945, 1902, 1876,
1739, 1672, 1493, 1437, 1027, 872, 799, 642 cmÀ1; HR-MS:
m/z=250.0213, calcd. for C13H11ClOS [M]+: 250.0214.
1H), 8.02 (dd, J=8.7, 1.7 Hz, 1H), 7.81–7.68 (m, 3H), 7.29
(t, J=7.9 Hz, 1H), 7.11 (d, J=8.1 Hz, 2H), 2.37 (s, 3H);
13C NMR (100 MHz, CDCl3): d=148.4, 141.7, 140.0, 139.4,
131.0, 130.4, 129.8, 122.2, 117.6, 109.0, 21.4; IR (KBr): n=
3072, 2964, 2918, 2855, 1529, 1486, 1419, 1342, 1207,1103,
1011, 860, 801, 724 cmÀ1; HR-MS: m/z=342.9849, calcd. for
C13H11NO2Te [M]+: 342.9847.
1-{4-[(4-Chlorophenyl)tellanyl]phenyl}ethanone
(3o):
Yield: 0.159 g (89%); yellow soild; mp 67–708C;1H NMR
(200 MHz, CDCl3): d=7.77–7.68 (m, 4H), 7.61 (d, J=
8.5 Hz, 2H), 7.24 (d, J=8.5 Hz, 2H), 2.56 (m, 3H);
13C NMR (50 MHz, CDCl3): d=197.6, 140.9, 136.2, 136.1,
135.4, 130.2, 129.0, 123.5, 111.0, 26.6; IR (KBr): n=3063,
3045, 3006, 1892, 1668, 1578, 1468, 1388, 1354, 1266, 956,
Acknowledgements
We gratefully acknowledge CNPq, TWAS, CAPES, INCT-
Catꢀlise and FAPESC-Pronex for financial support. S.S. and
J.R. would like to thank CNPq and TWAS for doctoral fel-
lowships. The authors are also grateful to CEBIME for the
HR-MS analysis.
848, 742, 599 cmÀ1
; HR-MS: m/z=360.9621, calcd. for
C14H12ClOTe [M+H]+: 360.9623.
3-[(4-Chlorophenyl)tellanyl]aniline (3p): Yield: 0.149 g
(90%); brown solid; mp: 58–608C; 1H NMR (200 MHz,
CDCl3): d=7.57 (d, J=8.2 Hz, 2H), 7.18–6.93 (m, 5H),
6.60–6.55 (m, 1H), 3.61(s, 2H); 13C NMR (50 MHz, CDCl3):
d=147.3, 139.1, 134.2, 130.3, 129.7, 128.2, 124.4, 115.0,
112.5; IR (KBr): n=3457, 3369, 3069, 3043, 2926, 2851,
1807, 1631, 1599, 1568, 1442, 1391, 1272, 1099, 1013, 993,
References
[1] a) S. Thurow, F. Penteado, G. Perin, R. G. Jacob, D.
Alves, E. J. Lenard¼o, Green Chem. 2014, 16, 3854–
3859; b) D. S. Rampon, L. A. Wessjohann, P. H.
Schneider, J. Org. Chem. 2014, 79, 5987–5992; c) C.
Santi, B. Battistelli, L. Testaferria, M. Tiecco, Green
Chem. 2012, 14, 1277–1280; d) V. G. Ricordi, C. S. Frei-
tas, G. Perin, E. J. Lenard¼o, R. G. Jacob, L. Savegnago,
D. Alves, Green Chem. 2012, 14, 1030–1034; e) K. N.
826, 791, 673 cmÀ1
; HR-MS: m/z=332.9551, calcd. for
C12H10ClNTe [M]+: 332.9548.
(4-Chlorophenyl)(3-nitrophenyl)tellane
(3q):
Yield:
0.160 g (89%); yellow solid; mp 90–928C; 1H NMR
(200 MHz, CDCl3): d=8.44 (s, 1H), 8.09 (dd, J=8.2, 1.6 Hz,
1H), 7.86 (d, J=7.6 Hz, 1H), 7.72 (d, J=8.2 Hz, 2H), 7.40-
6
asc.wiley-vch.de
ꢁ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 0000, 000, 0 – 0
ÝÝ
These are not the final page numbers!

FULL PAPERS
Synthesis of Unsymmetrical Diorganyl Chalcogenides
Carter, T. Taverner, C. H. Schiesser, M. M. Greenberg,
J. Org. Chem. 2000, 65, 8375–8378.
Zhu, J. R. Falck, Adv. Synth. Catal. 2014, 356, 2395–
2410; c) Boronic Acids: Preparation and Applications
in Organic Synthesis Medicine and Materials, (Ed.:
D. G. Hall), Wiley-VCH, Weinheim, 2011.
[2] a) B. Godoi, R. F. Schumacher, G. Zeni, Chem. Rev.
2011, 111, 2937–2980; b) G. Zeni, D. S. Lꢃdtke, R. B.
Panatieri, A. L. Braga, Chem. Rev. 2006, 106, 1032–
1076; c) G. Perin, E. J. Lenard¼o, R. G. Jacob, R. B.
Panatieri, Chem. Rev. 2009, 109, 1277–1301; d) K. P.
Bhabak, G. Mugesh, Acc. Chem. Res. 2010, 43, 1408–
1419; e) C. W. Nogueira, G. Zeni, J. B. T. Rocha, Chem.
Rev. 2004, 104, 6255–6286.
[3] a) The Chemistry of Organic Selenium and Tellurium
Compounds, Vol. 4, (Ed.: Z. Rappoport), Wiley &
Sons, Chichester, 2014; b) Handbook of Chalcogen
Chemistry: New Perspectives in Sulfur, Selenium and
Tellurium, 2nd edn., (Eds.: F. A. Devillanova, W.-W.
du Mont), RSC, Cambridge, 2013; c) Organoselenium
Chemistry: Synthesis and Reactions, (Ed.: T. Wirth),
Wiley-VCH, Weinheim 2011.
[4] a) M. Godoi, M. W. Paix¼o, A. L. Braga, Dalton Trans.
2011, 40, 11347–11355; b) A. L. Braga, D. S. Lꢃdtke,
J. A. Sehnem, E. E. Alberto, Tetrahedron 2005, 61,
11664–11671; c) C. C. Silveira, A. L. Braga, A. S.
Vieira, G. Zeni, J. Org. Chem. 2003, 68, 662–665; d) Y.
Nishiyama, A. Katsuura, A. Negoro, S. Hamanaka, N.
Miyoshi, Y. Yamana, A. Ogawa, N. Sonoda, J. Org.
Chem. 1991, 56, 3776–3780.
[5] a) E. E. Alberto, A. L. Braga, M. R. Detty, Tetrahedron
2012, 68, 10476–10481; b) F. V. Singh, T. Wirth, Org.
Lett. 2011, 13, 6504–6507; c) D. Das, P. Singh, M. Singh,
A. K. Singh, Dalton Trans. 2010, 39, 10876–10882.
[6] a) S. Thurow, N. T. Ostosi, S. R. Mendes, R. G. Jacob,
E. J. Lenard¼o, Tetrahedron Lett. 2012, 53, 2651–2653;
b) H. S. Kim, Y. J. Kim, H. Lee, K. Y. Park, C. Lee,
C. S. Chin, Angew. Chem. 2002, 114, 4476–4479;
Angew. Chem. Int. Ed. 2002, 41, 4300–4303.
[7] a) J.-D. Yu, W. Ding, G.-Y. Lian, K.-S. Song, D.-W.
Zhang, X. Gao, D. J. Yang, J. Org. Chem. 2010, 75,
3232–3239; b) K. C. Nicolaou, D. J. Edmonds, P. G.
Bulger, Angew. Chem. 2006, 118, 7292–7344; Angew.
Chem. Int. Ed. 2006, 45, 7134–7186; c) C. C. Silveira, A.
Machado, A. L. Braga, E. J. Lenard¼o, Tetrahedron
Lett. 2004, 45, 4077–4080.
[8] a) A. L. Braga, J. Rafique, in: The Chemistry of Organ-
ic Selenium and Tellurium Compounds, Vol. 4, (Ed.: Z.
Rappoport), Wiley & Sons, Chichester, 2013, Ch. 13–
15, pp 989–1174; b) L. A. Ba, M. Doring, V. Jamier, C.
Jacob, Org. Biomol. Chem. 2010, 8, 4203–4216; c) G.
Mugesh, W.-W. du Mont, H. Sies, Chem. Rev. 2001, 101,
2125–2179; d) L. Engman, N. Al-Maharik, M.
McNaughton, A. Birmingham, G. Powis, Anticancer
Drugs 2003, 2, 153–61; e) M. McNaughton, L. Engman,
A. Birmingham, G. Powis, I. A. Cotgreave, J. Med.
Chem. 2004, 47, 233–239.
[9] a) J. Gu, Z.-Q. Zhao, Y. Ding, H.-L. Chen, Y.-W.
Zhang, C.-H. Yan, J. Am. Chem. Soc. 2013, 135, 8363–
8371; b) A. Patra, Y. H. Wijsboom, G. Leitus, M. Bend-
ikov, Chem. Mater. 2011, 23, 896–906; c) T. Y. Ohul-
chanskyy, D. J. Donnelly, M. R. Detty, P. Prasad, J.
Phys. Chem. B 2004, 108, 8668–8672; d) M. R. Detty,
P. B. Merkel, J. Am. Chem. Soc. 1990, 112, 3845–3855.
[10] a) N. R. Candeias, F. Montalhano, P. M. S. D. Cal,
P. M. P. Gois, Chem. Rev. 2010, 110, 6169–6193; b) C.
[11] a) Comprehensive Organic Synthesis, Vol. 4, (Eds.:
B. M. Trost, I. Fleming), Pergamon Press, New York,
1991; b) N. Miyaura, Metal-Catalyzed Cross Coupling
Reactions, Vol. 1, (Eds. A. de Meijere, F. Diederich),
Wiley-VCH, Weinheim, 2004, pp 41–123; c) A. Krief,
in: ComprehensiveOrganometallic Chemistry II, Vol.
11, (Eds.: E. W. Abel, F. G. A. Stone, G. Wilkinson),
Pergamon Press, New York, 1995, Ch. 13.
[12] a) C. C. Eichman, J. P. Stambuli, J. Org. Chem. 2009,
74, 4005–4008; b) Y. Nishiyama, K. Tokunaga, N.
Sonoda, Org. Lett. 1999, 1, 1725–1727; c) T. Itoh, T.
Mase, Org. Lett. 2004, 6, 4587–4590; d) D. Barranano,
J. F. Hartwig, J. Am. Chem. Soc. 1995, 117, 2937–2938.
[13] N. Taniguchi, J. Org. Chem. 2004, 69, 6904–6906.
[14] a) D. Alves, J. M. Pena, A. S. Vieira, G. V. Botteselle,
R. C. Guadagnin, H. A. Stefani, J. Braz. Chem. Soc.
2009, 20, 988–992; b) A. Kumar, S. Kumar, Tetrahedron
2014, 70, 1763–1772; c) N. Taniguchi, J. Org. Chem.
2007, 72, 1241–1245; d) D. Alves, C. G. Santos, M. W.
Paixao, L. C. Soares, D. de Souza, O. E. D. Rodrigues,
A. L. Braga, Tetrahedron Lett. 2009, 50, 6635–6638.
[15] D. Kundu, S. Ahammed, B. C. Ranu, Green Chem.
2012, 14, 2024–2030.
[16] M. Wang, K. Ren, L. Wang, Adv. Synth. Catal. 2009,
351, 1586–1594.
[17] K. Ren, M. Wang, L. Wang, Org. Biomol. Chem. 2009,
7, 4858–4861.
[18] S. Kumar, L. Engman, J. Org. Chem. 2006, 71, 5400–
5403.
[19] a) M. Iwasaki, W. Kaneshika, Y. Tsuchiya, K. Nakaji-
ma, Y. Nishihara, J. Org. Chem. 2014, 79, 11330–11338;
b) C. D. Prasad, S. Kumar, M. Sattar, A. Adhikarya, S.
Kumar, Org. Biomol. Chem. 2013, 11, 8036–8040;
c) C. D. Prasad, S. J. Balkrishna, A. Kumar, B. S. Bha-
kuni, K. Shrimali, S. Biswas, S. Kumar, J. Org. Chem.
2013, 78, 1434–1443.
[20] a) X. Wu, Q. Gao, S. Liu, A. Wu, Org. Lett. 2014, 16,
2888–2891; b) W. Ge, Y. Wei, Green Chem. 2012, 14,
2066–2070; c) R. N. Reddi, P. K. Prasad, A. Sudalai,
Org. Lett. 2014, 16, 5674–5677; d) F. Xiao, H. Xie, S.
Liu, G.-J. Geng, Adv. Synth. Catal. 2014, 356, 364–368.
[21] J. B. Azeredo, M. Godoi, G. M. Martins, C. C. Silveira,
A. L. Braga, J. Org. Chem. 2014, 79, 4125–4130.
[22] a) J. Rafique, S. Saba, A. R. Rosario, G. Zeni, A. L.
Braga, RSC Adv. 2014, 4, 51648–51652; b) M. Godoi,
G. V. Botteselle, J. Rafique, M. S. T. Rocha, J. M. Pena,
A. L. Braga, Asian J. Org. Chem. 2013, 2, 746–749;
c) D. Singh, S. Narayanaperumal, K. Gul, M. Godoi,
O. E. D. Rodriques, A. L. Braga, Green Chem. 2010,
12, 957–960.
[23] a) C. Zhu, J. R. Falck, Adv. Synth. Catal. 2014, 356,
2395–2410; b) F. Xiao, H. Xie, S. Liu, G.-J. Deng, Adv.
Synth. Catal. 2014, 356, 364–368.
[24] a) M. Tamres, S. N. Bhat, J. Am. Chem. Soc. 1972, 94,
2577–2582; b) S. J. Lo, M. Tamres, Can. J. Chem. 1983,
61, 1933–1939.
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
7
ÞÞ
These are not the final page numbers!

FULL PAPERS
8 Synthesis of Unsymmetrical Diorganyl Chalcogenides under
Greener Conditions: Use of an Iodine/DMSO System,
Solvent- and Metal-Free Approach
Adv. Synth. Catal. 2015, 357, 1 – 8
Sumbal Saba, Jamal Rafique, Antonio L. Braga*
8
asc.wiley-vch.de
ꢁ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 0000, 000, 0 – 0
ÝÝ
These are not the final page numbers!