Glycerol as Precursor of Organoselanyl and Organotellanyl Alkynes

Article abstract of DOI:10.3390/molecules22030391

Herein we describe the synthesis of organoselanyl and organotellanyl alkynes by the addition of lithium alkynylchalcogenolate (Se and Te) to tosyl solketal, easily obtained from glycerol. The alkynylchalcogenolate anions were generated in situ and added to tosyl solketal in short reaction times, furnishing in all cases the respective products of substitution in good yields. Some of the prepared compounds were deprotected using an acidic resin to afford new water-soluble 3-organotellanylpropane-1,2-diols. The synthetic versatility of the new chalcogenyl alkynes was demonstrated in the iodocyclization of 2,2-dimethyl-1,3-dioxolanylmethyl(2-methoxyphenylethynyl)selane 3f, which afforded 3-iodo-2-(2,2-dimethyl-1,3-dioxolanylmethyl) selenanylbenzo[b]furan in 85% yield, opening a new way to access water-soluble Se-functionalized benzo[b]furanes.

Full text of DOI:10.3390/molecules22030391

molecules
Communication
Glycerol as Precursor of Organoselanyl and
Organotellanyl Alkynes
Eder J. Lenardão 1,*, Elton L. Borges 1, Guilherme Stach 1, Liane K. Soares 1, Diego Alves 1,
Ricardo F. Schumacher 1, Luana Bagnoli 2, Francesca Marini 2 and Gelson Perin 1,
*
1
Laboratório de Síntese Orgânica Limpa (LASOL), Centro de Ciências Químicas, Farmacêuticas e de
Alimentos (CCQFA), Universidade Federal de Pelotas (UFPel), P.O. Box 354, 96010-900 Pelotas, RS, Brazil;
chemistry_borges@yahoo.com.br (E.L.B.); guilherme.stach13@gmail.com (G.S.);
lianekrolowsoares@yahoo.com.br (L.K.S.); dsalves@gmail.com (D.A.);
ricardo.schumacher@ufpel.edu.br (R.F.S.)
2
Department of Pharmaceutical Sciences, Group of Catalysis and Organic Green Chemistry, University of
Perugia, Via del Liceo 1, 06100 Perugia, Italy; luana.bagnoli@unipg.it (L.B.); francesca.marin i@unipg.it (F.M.)
Correspondence: lenardao@ufpel.edu.br (E.J.L.); gelson_perin@ufpel.edu.br (G.P.);
Tel.: +55-53-3275-7533 (E.J.L. & G.P.)
*
Academic Editor: Derek J. McPhee
Received: 24 January 2017; Accepted: 28 February 2017; Published: 2 March 2017
Abstract: Herein we describe the synthesis of organoselanyl and organotellanyl alkynes by
the addition of lithium alkynylchalcogenolate (Se and Te) to tosyl solketal, easily obtained
from glycerol. The alkynylchalcogenolate anions were generated in situ and added to tosyl
solketal in short reaction times, furnishing in all cases the respective products of substitution
in good yields. Some of the prepared compounds were deprotected using an acidic resin
to afford new water-soluble 3-organotellanylpropane-1,2-diols. The synthetic versatility of
the new chalcogenyl alkynes was demonstrated in the iodocyclization of 2,2-dimethyl-1,3-
dioxolanylmethyl(2-methoxyphenylethynyl)selane 3f, which afforded 3-iodo-2-(2,2-dimethyl-1,3-
dioxolanylmethyl) selenanylbenzo[b]furan in 85% yield, opening a new way to access water-soluble
Se-functionalized benzo[b]furanes.
Keywords: selenium; tellurium; 1,3-dioxolanes; glycerol; alkynes
1. Introduction
Organochalcogen chemistry is considered a very broad field due to the increasing research
on the synthesis [
and organotellanyl alkynes have become extensively studied due their pharmacological and
biological activities [10 13] and their use as starting material in organic synthesis [ 14 16].
For example, organotellanyl alkynes exhibited antidepressive-like activity [17], while alkyne-derived
organotellanyl alkenes showed in vitro antioxidant activity with slight toxicity [18 19]. Additionally,
1–5] and applications [2,6–9] of this class of compounds. Besides, organoselanyl
–
2, –
,
chalcogenyl alkynes are useful in electrophilic cyclization reactions to prepare benzo[b]furans [20],
in [4 + 2]-cycloadditions to produce the corresponding 2-chalcogenyl-1-halonaphthalenes [21], and in
the synthesis of bis-phenylchalcogen alkenes [22
papers are restricted to the synthesis of chalcogenyl alkynes starting mainly from aromatic terminal
alkynes [24 30], with only a few methods to prepare aliphatic alkynylselenides and tellurides with
,23]. Despite all the advances in this area, most of the
–
different chalcogen substitution patterns.
On the other hand, with the increasing overproduction of glycerol [31], solketal has become a
useful intermediate in chemical transformations using glycerol as a raw material. It is well accepted
that tosyl solketal plays an important role in a vast array of applications [32–36]; standing out is its use
Molecules 2017, 22, 391; doi:10.3390/molecules22030391
www.mdpi.com/journal/molecules

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as a building block in organic synthesis. Recently, tosyl solketal was used as starting material for the
synthesis of several biologically active compounds [36 37]. The synthesis of a series of organochalcogen
,
glycerol derivatives was described, including chalcogen ethers [38
as well as enantiomerically pure selenides and diselenides [40].
,39] with antioxidant activity [38],
In a previous paper [41], we described a convenient procedure for the synthesis of new vinyl
chalcogenides by the reaction of glycerol-derived dichalcogenides with terminal alkynes in the presence
of NaBH4, using PEG-400 as the solvent. Chalcogenyl alkynes were selectively prepared from the
same starting materials, when ethanol was the solvent. However, reaction times were in the range
of 5 to 26 h, and the scope of the reaction was limited to organoselanyl alkynes, since the synthesis
of only one organotellanyl alkyne in 55% yield was reported [41]. Trying to solve these limitations,
and in continuation of our studies on the synthesis and reactivity of chalcogenyl alkynes, herein we
describe a general and efficient synthesis of a new glycerol-derived organoselanyl and organotellanyl
alkyne 3
via the nucleophilic substitution of lithium alkynylchalcogenolate 10 (Se and Te) with tosyl
solketal 2 (Scheme 1).
Scheme 1. General scheme of the reaction.
2. Results and Discussion
The first step of the reaction is the preparation of the nucleophilic species 10a
–i, which were
prepared in situ using a butyllithium solution and THF as the solvent. Phenylacetylene 1a (1.0 mmol)
and elemental selenium (1.0 mmol) were used as standard reagents to optimize the preparation of the
respective alkynylselenolate 10a (R = C6H5; Y = Se) at 0 ◦C under N2 atmosphere. After stirring for
20 min at 0 ◦C, racemic tosyl solketal
2 (1.2 mmol) was added and the mixture was stirred at room
temperature for an additional 1 h, giving 2,2-dimethyl-1,3-dioxolanylmethyl(phenylethynyl)selane 3a
in 20% yield. When the reaction time was extended to 3 h, the yield was increased to 30%, but side
products were also observed. Next, the amount of tosyl solketal
related to the alkynylselenolate anion 10a) and after 3 h at r.t., 3a was isolated in 50% yield. However,
the best performance of this reaction was achieved when the amount of tosyl solketal was decreased
to 0.5 mmol (0.5 equiv. related to 10a), affording 3a in 80% yield after 3 h. By using 0.7 equiv. of tosyl
solketal , a decrease in the yield of product 3a was observed (42%). These findings indicate that a
2 was reduced to 1.0 mmol (1 equiv.
2
2
large excess of chalcogenolate anion is mandatory for the reaction.
After determining the best conditions to prepare 3a, the protocol was extended to the differently
substituted aliphatic and aromatic terminal alkynes 1b–h (Table 1, entries 2–8). As shown in Table 1,
a number of selenanyl alkynes were prepared in good yields. Starting from aliphatic hex-1-yne 1b
,
2,2-dimethyl-1,3-dioxolanylmethyl(hex-1-yn-1-yl)selane 3b was obtained in 63% yield. This is a good
outcome, considering that an aliphatic alkyne was used as the starting material (Table 1, entry 2).
In principle, the presence of substituents in the aromatic ring of alkynes 1c
impact the reactivity, since all the respective products were obtained in lower yields. Experiments
have shown that the overall result is similar in both situations; i.e., the yields of products 3c are
–g seems to negatively
–
g
reduced to 60%–70% (Table 1, entries 3–7). Ethynylcyclohex-1-ene 1h afforded the respective selenanyl
alkyne 3h in 52% yield, showing that the reaction can be successfully applied to conjugated enynes
(Table 1, entry 8).
The optimized protocol was employed using tellurium instead selenium, in order to prepare
organotellanyl alkynes 3i
–m. However, by reacting phenylacetylene 1a with elemental tellurium
under the same reaction conditions employed for the selenium derivatives, the respective

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2,2-dimethyl-1,3-dioxolanylmethyl(phenylethynyl)tellane 3i was obtained in only 30% yield after
3 h. Trying to improve the yield of 3i, the same procedure was repeated, but the tosyl solketal 2 was
added at 0 ◦C and the temperature maintained at 0 ◦C for an additional 3 h. In this case, the desired
product 3h was obtained only in trace amounts, with a large amount of the bis(phenylethynyl)tellane as
side product. Then, an additional test was performed: after addition of the solketal
2 to the previously
formed alkynyltellurolate 10 at 0 ◦C, the ice bath was replaced by an oil bath and the reaction mixture
was stirred under reflux for 1.5 h. To our delight, this reaction afforded the desired tellanyl alkyne 3i
in 85% yield (Table 1, entry 9). Under the new conditions, the reaction scope could be expanded to
other alkynes and the respective tellanyl alkynes were obtained in good yields, similar to the selanyl
alkynes analogues (Table 1, entries 10–13).
Table 1. Scope of the synthesis of organoselanyl 3a–h and organotellanyl alkynes 3i–m a.
Yield (%) b
Entry
Alkyne 1
Y
Product 3
1
Se
80
2
3
4
Se
Se
Se
63
65
70
5
6
7
Se
Se
Se
60
60
67

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Table 1. Cont.
Yield (%) b
Entry
Alkyne 1
Y
Product 3
8
Se
52
9
1a
1b
1c
Te
Te
Te
85
63
55
10
11
12
1h
Te
Te
61
63
13
a
Reaction was performed using alkyne
1
(1.0 mmol), Se0 or Te0 (1.0 mmol), butyllithium solution (1.6 mol/L in
(0.5 mmol) in THF (2.0 mL)
) or under reflux for 1.5 h (3i
); b Yields are given
hexanes; 1.0 mmol) at 0 ◦C in THF (5.0 mL) under N2 atmosphere. Then, tosyl solketal
was added at r.t. and the mixture stirred for additional 3 h (3a
2
–h
–m
for isolated products.
Due to our interest in the synthetic applications of organochalcogen compounds, as well as
in studying new possibilities in their biological activities, we performed the synthesis of new
3-organotellanylpropane-1,2-diols
4
(Table 2). Starting from the organotellanyl alkynes 3i
, 3l, and
3m, the 3-tellanylpropane-1,2-diols 4a
–
c
were obtained in moderate yields by treatment with Dowex
50WX8 (H+ form) in methanol, after 5 h (Table 2, entries 1–3). These new compounds generally showed
a good solubility in water, which will facilitate biological tests where aqueous medium is required
(Table 2).
Selanyl alkynes with an appropriate substitution pattern are attractive intermediates in organic
synthesis [20]. For example, the intramolecular electrophilic cyclization of 3f with iodine was
easily conduced in CH2Cl2 at r.t. for 1 h, delivering 85% yield of the densely functionalized
3-iodo-2-(2,2-dimethyl-1,3-dioxolanylmethyl)selenanylbenzo[b]furan
5 (Scheme 2). The combination
of a selenium group with the benzo[b]furan scaffold could be an interesting strategy in the prospection
of new drug candidates.

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Table 2. Synthesis of new 3-organotellanylpropane-1,2-diols 4a–c a.
Solubility
Entry
Tellanyl Alkyne 3
Diol 4
Yield (%) c
(mg/mL) b
1
2.3
50
2
2.8
1.5
50
47
3
a
Reaction was performed using 1.0 mmol of 3
, 1.112 g of Dowex® in 2.5 mL of MeOH at r.t. for 5 h; b Solubility
measured in water; c Yields are given for isolated products.
Scheme 2. Synthesis of 3-iodo-2-(2,2-dimethyl-1,3-dioxolanylmethyl)selenanylbenzo[b]furan 5.
3. Experimental Section
3.1. General Information
The reactions were monitored by thin layer chromatography (TLC) carried out on Merck (Merck,
Darmstadt, Germany) silica gel (60 F254) by using UV light as visualizing agent and 5% vanillin in 10%
H2SO4 and heat as developing agent. NMR spectra were recorded with Bruker spectrometer (Bruker,
Billerica, MA, USA) DPX 300, DPX 400, and DPX 500 (300, 400, and 500 MHz, respectively) instruments
using CDCl3 as solvent and calibrated using tetramethylsilane (TMS) as internal standard. Chemical
shifts (δ) are reported in ppm, coupling constants (J) are reported in Hertz. The NMR spectra are
found in the Supplementary Materials. Low-resolution mass spectra were obtained with a Shimadzu
GC-MS-QP2010 mass spectrometer (Shimadzu Corporation, Kyoto, Japan) and molecular ion values
are reported according the exact mass. High-resolution mass spectra (HMRS) were recorded on a
Shimadzu LC-MS-IT-TOF spectrometer (Shimadzu Corporation). Melting points were determined
using a Marte PFD III melting point instrument (Marte Científica, Minas Gerais, Brazil).
3.2. General Procedure for Synthesis of Organoselanyl Alkynes 3a–h
To a solution of alkyne
1
(1.0 mmol) in THF (5.0 mL) under N2 atmosphere, BuLi (1.6 mol/L
◦
in hexanes; 1.0 mmol) was added at 0 C. After 20 min, the temperature was increased to room
temperature, and elemental selenium (Se0, 1.0 mmol) was added. The stirring at room temperature
was maintained until all selenium was consumed, and then a solution of racemic tosyl solketal
2
(0.5 mmol) in THF (2.0 mL) was added. After stirring for 3 h, the reaction mixture was quenched with

Molecules 2017, 22, 391
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water (15.0 mL) and extracted with ethyl acetate (3
over MgSO4, and the solvent was evaporated under reduced pressure. The product was isolated by
column chromatography using hexanes/ethyl acetate as eluent.
×
15.0 mL). The organic phase was separated, dried
Analytical Data of Products 3a–h
2,2-Dimethyl-1,3-dioxolanylmethyl(phenylethynyl)selane 3a (Table 1, entry 1) [41]: Yield: 0.118 g (80%);
1
yellow oil. H-NMR (CDCl3, 300 MHz);
δ
(ppm): 7.38–7.42 (m, 2H, Ar-H), 7.27–7.32 (m, 3H, Ar-H),
CH), 3.88 (dd, J = 8.6 and 5.8 Hz, 1H,
CH), 2.94 (dd, J = 12.1 and 7.7 Hz, 1H, Se- CH), 1.45
(ppm): 131.5,
4.46–4.54 (m, 1H, O-CH), 4.21 (dd, J = 8.6 and 6.0 Hz, 1H, O-
H
O- CH), 3.07 (dd, J = 12.1 and 5.2 Hz, 1H, Se-
H
H
H
(d, J = 0.5 Hz, 3H, C-CH3), 1.37 (d, J = 0.5 Hz, C-CH3). 13C-NMR (CDCl3, 75 MHz);
δ
128.3 (3C), 123.2, 109.7, 99.4, 75.3, 69.3, 68.9, 31.8, 27.0, 25.5. MS: m/z (rel. int.) 296 (M+, 8.7), 181 (43.8),
115 (25.9), 102 (26.4), 43 (100.0).
2,2-Dimethyl-1,3-dioxolanylmethyl(hex-1-yn-1-yl)selane 3b (Table 1, entry 2) [41]: Yield: 0.087 g (63%);
yellow oil. MS: m/z (rel. int.) 276 (M+, 8.5), 101 (39.1), 79 (22.4), 57 (31.0), 43 (100.0).
2,2-Dimethyl-1,3-dioxolanylmethyl(4-methylphenylethynyl)selane 3c (Table 1, entry 3) [41]: Yield: 0.101 g
(65%); yellow solid. m.p. 45–47 ◦C. MS: m/z (rel. int.) 310 (M+, 23.7), 195 (66.0), 115 (87.0), 57 (66.0),
43 (100.0).
2,2-Dimethyl-1,3-dioxolanylmethyl(2-methylphenylethynyl)selane 3d (Table 1, entry 4) [41]: Yield: 0.109 g
(70%); yellow oil. MS: m/z (rel. int.) 310 (M+, 9.3), 195 (12.4), 115 (100.0), 101 (10.0), 43 (39.7).
2,2-Dimethyl-1,3-dioxolanylmethyl(4-methoxyphenylethynyl)selane 3e (Table 1, entry 5) [41]: Yield: 0.098 g
◦
(60%); yellow solid; m.p. 39–41 C. 1H-NMR (CDCl3, 400 MHz);
δ
(ppm): 7.27 (d, J = 8.9 Hz, 2H, Ar-H),
6.74 (d, J = 8.9 Hz, 2H, Ar-H), 4.37–4.43 (m, 1H, O-CH), 4.12 (dd, J = 8.5 and 6.0 Hz, 1H, O- CH), 3.79
(dd, J = 8.5 and 5.9 Hz, 1H, O- CH), 3.71 (s, 3H, Ar-OCH3), 2.98 (dd, J = 12.1 and 5.1 Hz, 1H, Se- CH),
2.84 (dd, J = 12.1 and 7.7 Hz, 1H, Se-
CH), 1.37 (s, 3H, C-CH3), 1.29 (s, 3H, C-CH3). 13C-NMR (CDCl3,
H
H
H
H
100 MHz); δ (ppm): 159.8, 133.3, 115.5, 113.9, 109.7, 99.3, 75.4, 69.0, 67.3, 55.2, 31.8, 27.0, 25.5. MS: m/z
(rel. int.) 326 (M+, 3.4), 211 (39.3), 196 (20.2), 132 (57.1), 43 (100.0).
2,2-Dimethyl-1,3-dioxolanylmethyl(2-methoxyphenylethynyl)selane 3f (Table 1, entry 6): Yield: 0.098 g
1
(60%); yellow oil. H-NMR (CDCl3, 400 MHz);
δ
(ppm): 7.35–7.37 (m, 1H, Ar-H), 7.24–7.28 (m, 1H,
CH), 3.93 (dd, J = 7.7
CH), 3.86 (s, 3H, Ar-OCH3), 3.08 (dd, J = 12.0 and 4.0 Hz, 1H, Se- CH), 2.93
(dd, J = 12.0 and 8.0 Hz, 1H, Se-
CH), 1.45 (s, 3H, C-CH3), 1.37 (s, 3H, C-CH3). 13C-NMR (CDCl3,
100 MHz);
Ar-H), 6.84–6.90 (m, 2H, Ar-H), 4.50–4.56 (m, 1H, O-CH), 4.21–4.25 (m, 1H, O-
and 6.1 Hz, 1H, O-
H
H
H
H
δ
(ppm): 160.1, 133.3, 129.6, 120.3, 112.4, 110.5, 109.5, 95.7, 75.5, 73.0, 69.0, 55.6, 31.7, 26.9,
25.5. MS: m/z (rel. int.) 326 (M+, 29.4), 131 (100.0), 119 (51.2), 57 (71.9), 43 (91.4). HRMS: Calculated
mass to C15H18O3Se: [M]+ 326.0421, found: 326.0439.
2,2-Dimethyl-1,3-dioxolanylmethyl(4-fluorophenylethynyl)selane 3g (Table 1, entry 7) [41]: Yield: 0.105 g
(67%); yellow solid; m.p. 37–39 ◦C. MS: m/z (rel. int.) 314 (M+, 0.3), 199 (32.2), 120 (27.1), 107 (90.6),
43 (100.0).
2,2-Dimethyl-1,3-dioxolanylmethyl(cyclohex-1-en-1-ylethynyl)selane 3h (Table 1, entry 8): Yield: 0.078 g
1
(52%); yellow oil. H-NMR (CDCl3, 400 MHz);
δ
(ppm): 6.07–6.09 (m, 1H, C=CH), 4.41–4.45 (m, 1H,
CH), 3.83 (dd, J = 8.5 and 5.9 Hz, 1H, O- CH), 2.99
CH), 2.84 (dd, J = 12.1 and 8.0 Hz, 1H, Se- CH), 2.09–2.10 (m, 4H),
1.55–1.65 (m, 4H), 1.43 (s, 3H, C-CH3), 1.36 (s, 3H, C-CH3). 13C-NMR (CDCl3, 100 MHz);
(ppm): 135.3,
O-CH), 4.18 (dd, J = 8.5 and 6.0 Hz, 1H, O-
(dd, J = 12.1 and 5.0 Hz, 1H, Se-
H
H
H
H
δ
121.0, 109.6, 101.5, 75.5, 69.0, 65.7, 31.6, 29.1, 27.0, 25.61, 25.56, 22.3, 21.4. MS: m/z (rel. int.) 300 (M+, 6.0),
185 (6.7), 104 (35.1), 91 (19.9), 43 (100.0). HRMS: Calculated mass to C14H20O2Se: [M + H]+ 301.0707,
found: 301.0690.

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3.3. General Procedure for the Synthesis of Organotellanyl Alkynes 3i–m
To a solution of alkyne
1
(1.0 mmol) in THF (5.0 mL) under N2 atmosphere, BuLi (1.6 mol/L
◦
in hexanes; 1.0 mmol) was added at 0 C. After 20 min, the temperature was increased to room
temperature and elemental tellurium (Te0, 1.0 mmol) was added. The stirring at room temperature
was maintained until all tellurium has been consumed and then a solution of racemic tosyl solketal
2
(0.5 mmol) in THF (2.0 mL) was added and the mixture was stirred under reflux for additional
1.5 h. After, the reaction mixture was quenched with water (15.0 mL) and extracted with ethyl acetate
(3 × 15.0 mL). The organic phase was separated, dried over MgSO4, and the solvent was evaporated
under reduced pressure. The product was isolated by column chromatography using hexanes/ethyl
acetate as eluent.
Analytical Data of Products 3i–m
2,2-Dimethyl-1,3-dioxolanylmethyl(phenylethynyl)tellane 3i (Table 1, entry 9) [41]: Yield: 0.147 g (85%); red
1
oil. H-NMR (CDCl3, 400 MHz);
δ
(ppm): 7.31–7.34 (m, 2H, Ar-H), 7.18–7.25 (m, 3H, Ar-H), 4.38–4.44
CH), 3.73 (dd, J = 8.4 and 6.1 Hz, 1H, O- CH),
(m, 1H, O-CH), 4.12 (dd, J = 8.4 and 6.1 Hz, 1H, O-
H
H
3.00–3.08 (m, 2H, Te-CH2), 1.37 (s, 3H, C-CH3), 1.28 (s, 3H, C-CH3). 13C-NMR (CDCl3, 100 MHz);
δ
(ppm): 131.7, 128.3, 128.2, 123.4, 111.3, 109.7, 75.9, 70.0, 44.2, 27.0, 25.6, 13.6. MS: m/z (rel. int.) 346 (M+,
32.7), 231 (58.2), 101 (75.7), 57 (100.0), 43 (77.0).
2,2-Dimethyl-1,3-dioxolanylmethyl(hex-1-yn-1-yl)tellane 3j (Table 1, entry 10): Yield: 0.103 g (63%); red
1
oil. H-NMR (CDCl3, 500 MHz);
O-
δ
(ppm): 4.41–4.46 (m, 1H, O-CH), 4.18 (dd, J = 8.4 and 6.0 Hz, 1H,
CH), 3.02 (dd, J = 11.7 and 5.2 Hz, 1H, Te- CH), 2.97
CH), 2.48 (t, J = 7.0 Hz, 2H, CH2Csp), 1.47–1.53 (m, 2H), 1.43 (s, 3H,
H
CH), 3.77 (dd, J = 8.4 and 6.4 Hz, 1H, O-
H
H
(dd, J = 11.7 and 7.6 Hz, 1H, Te-
H
C-CH3), 1.37–1.43 (m, 2H), 1.35 (s, 3H, C-CH3), 0.91 (t, J = 7.3 Hz, 3H). 13C-NMR (CDCl3, 125 MHz);
δ
(ppm): 112.8, 109.7, 76.2, 70.0, 31.0, 27.0, 25.6, 21.9, 20.6, 13.5, 12.4. MS: m/z (rel. int.) 326 (M+, 21.5), 115
(63.0), 81 (79.9), 57 (100.0), 43 (77.2). HRMS: Calculated mass for C12H20O2Te: [M + OH]+ 343.0553,
found: 343.0533.
2,2-Dimethyl-1,3-dioxolanylmethyl(4-methylphenylethynyl)tellane 3k (Table 1, entry 11): Yield: 0.099 g
1
(55%); red oil. H-NMR (CDCl3, 500 MHz);
δ
(ppm): 7.29 (d, J = 8.1 Hz, 2H, Ar-H), 7.10 (d, J = 8.1 Hz,
CH), 3.81 (dd, J = 8.4 and
CH), 3.10–3.11 (m, 2H, Te-CH2), 2.35 (s, 3H, Ar-CH3), 1.45 (s, 3H, C-CH3), 1.35 (s, 3H,
2H, Ar-H), 4.45–4.50 (m, 1H, O-CH), 4.20 (dd, J = 8.4 and 6.0 Hz, 1H, O-
H
6.4 Hz, 1H, O-
H
C-CH3). 13C-NMR (CDCl3, 125 MHz);
δ (ppm): 138.6, 131.7, 128.9, 120.4, 111.4, 109.7, 76.0, 70.0, 42.9,
27.0, 25.6, 21.4, 13.5. MS: m/z (rel. int.) 360 (M+, 12.8), 245 (27.8), 115 (100.0), 57 (78.9), 43 (75.2). HRMS:
Calculated mass for C15H18O2Te: [M + H]+ 361.0447, found: 361.0469.
2,2-Dimethyl-1,3-dioxolanylmethyl(cyclohex-1-en-1-ylethynyl)tellane 3l (Table 1, entry 12): Yield: 0.107 g
1
(61%); yellow oil; H-NMR (CDCl3, 500 MHz);
δ
(ppm): 6.06–6.09 (m, 1H, C=CH), 4.42–4.47 (m,
CH ), 3.78 (dd, J = 8.4 and 6.4 Hz, 1H, O- CH),
1H, O-CH), 4.19 (dd, J = 8.4 and 5.9 Hz, 1H, O-
H
H
3.02–3.03 (m, 2H, Te-CH2), 2.08–2.16 (m, 4H), 1.54–1.65 (m, 4H), 1.44 (s, 3H, C-CH3), 1.35 (s, 3H, C-CH3).
13C-NMR (CDCl3, 125 MHz);
δ (ppm): 135.9, 121.1, 113.5, 109.7, 76.2, 70.0, 39.9, 29.2, 27.0, 25.6, 25.5,
22.2, 21.4, 13.2. MS: m/z (rel. int.) 350 (M+, 40.3), 115 (31.8), 105 (100.0), 57 (92.9), 43 (73.8). HRMS:
Calculated mass for C14H20O2Te: [M + H]+ 351.0604, found: 351.0597.
2,2-Dimethyl-1,3-dioxolanylmethyl(4-tert-buthylphenylethynyl)tellane 3m (Table 1, entry 13): Yield: 0.127 g
1
(63%); red oil. H NMR (CDCl3, 500 MHz);
δ
(ppm): 7.31–7.35 (m, 4H, Ar-H), 4.46–4.51 (m, 1H, O-CH),
CH ), 3.81 (dd, J = 8.4 and 6.4 Hz, 1H, O- CH), 3.10–3.11 (m, 2H,
Te-CH2), 1.45 (s, 3H, C-CH3), 1.35 (s, 3H, C-CH3), 1.30 (s, 9H, C-CH3). 13C NMR (CDCl3, 125 MHz);
4.21 (dd, J = 8.4 and 6.0 Hz, 1H, O-
H
H
δ
(ppm): 151.7, 131.6, 125.2, 120.4, 111.5, 109.7, 76.1, 70.0, 42.9, 34.7, 31.1, 27.0, 25.6, 13.5. MS: m/z (rel.
int.) 402 (M+, 26.2), 287 (19.6), 143 (66.4), 57 (99.7), 43 (100.0). HRMS: Calculated mass for C18H24O2Te:
[M + H]+ 403.0917, found: 403.0908.

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3.4. General Procedure for the Synthesis of 3-(Organotellanyl)propane-1,2-diol 4a–c
To a solution of the respective organotellanyl alkyne
3
(1.0 mmol) in MeOH (2.5 mL) Dowex®
acidic ion-exchange resin (50WX8 20–50 mesh; 1.122 g) was added at room temperature. The reaction
mixture was stirred for 5 h at room temperature and then it was filtered and washed with MeOH. The
filtrate was concentrated and chromatographed (50% EtOAc/hexanes).
Analytical Data of Products 4a–c
1
3-(Phenylethynyltellanyl)propane-1,2-diol 4a (Table 2, entry 1): Yield: 0.153 g (50%); red oil. H-NMR
(CDCl3, 400 MHz);
δ
(ppm): 7.39–7.41 (m, 2H, Ar-H), 7.26–7.32 (m, 3H, Ar-H), 4.04–4.09 (m, 1H, O-CH),
CH), 3.66 (dd, J = 11.3 and 6.1 Hz, 1H, O- CH), 2.81–3.07 (m,
3.81 (dd, J = 11.3 and 3.1 Hz, 1H, O-
H
H
4H, Te-CH2 and 2 O-H). 13C-NMR (CDCl3, 100 MHz);
δ (ppm): 131.8, 128.4, 128.2, 123.4, 111.2, 71.5,
66.6, 45.1, 14.8. MS: m/z (rel. int.) 306 (M+, 7.9), 231 (11.7), 155 (44.9), 102 (43.7), 91 (100.0). HRMS:
Calculated mass for C11H12O2Te: [M + H]+ 306.9978, found: 306.9903.
3-(Cyclohex-1-en-1-ylethynyltellanyl)propane-1,2-diol 4b (Table 2, entry 2): Yield: 0.155 g (50%); yellow
1
oil. H-NMR (CDCl3, 400 MHz);
δ
(ppm): 6.07–6.10 (m, 1H, C=CH), 4.0–4.06 (m, 1H, O-CH), 3.79 (dd,
CH ), 3.65 (dd, J = 11.3 and 6.1 Hz, 1H, O- CH), 2.76–3.0 (m, 4H, Te-CH2
(ppm): 136.1, 121.1,
J = 11.3 and 3.4 Hz, 1H, O-
H
H
and 2 O-H), 2.07–2.17 (m, 4H), 1.54–1.65 (m, 4H). 13C-NMR (CDCl3,100 MHz);
δ
113.5, 71.7, 66.5, 40.7, 29.3, 25.5, 22.2, 21.4, 14.5. MS: m/z (rel. int.) 310 (M+, 20.6), 235 (6.8), 105 (100.0),
91 (43.0), 79 (54.0). HRMS: Calculated mass for C11H16O2Te: [M + H]+ 311.0291, found: 311.0273.
3-(4-tert-Buthylphenylethynyltellanyl)propane-1,2-diol 4c (Table 2, entry 3): Yield: 0.170 g (47%); red oil.
1H-NMR (CDCl3, 400 MHz);
δ
(ppm): 7.29–7.35 (m, 4H, Ar-H), 4.03–4.09 (m, 1H, O-CH), 3.80 (dd,
J = 11.4 and 3.1 Hz, 1H, O-
H
CH), 3.64 (dd, J = 11.4 and 6.2 Hz, 1H, O- CH), 3.03–3.30 (m, 4H, Te-CH2
H
and 2 O-H), 1.28 (s, 9H, C-CH3). 13C-NMR (CDCl3, 100 MHz);
δ (ppm): 151.8, 131.6, 125.2, 120.4, 111.3,
71.6, 66.5, 44.3, 34.7, 31.1, 14.7. MS: m/z (rel. int.) 362 (M+, 20.2), 288 (11.4), 143 (100), 57 (98.2), 41 (44.1).
HRMS: Calculated mass for C15H20O2Te: [M + H]+ 363.0604, found: 363.0583.
3.5. Procedure for the Synthesis of the 3-Iodo-2-(2,2-dimethyl-1,3-dioxolanylmethyl)selenanylbenzo[b]furan 5
To a solution of 2,2-dimethyl-1,3-dioxolanylmethyl(2-methoxyphenylethynyl)selane 3f (0.25 mmol) in
CH2Cl2 (2.0 mL) a solution of I2 (0.28 mmol) in CH2Cl2 (3.0 mL) was added. The reaction mixture
was stirred for 1 h at room temperature. Then, saturated aqueous Na2S2O3 was added to remove the
excess of I2. The mixture was then extracted with ethyl acetate (3
separated, dried over MgSO4 and concentrated under vacuum. The product was isolated by column
chromatography using hexanes/ethyl acetate as eluent.
×
10 mL) and the organic phase was
Analytical Data of Product 5
3-Iodo-2-(2,2-dimethyl-1,3-dioxolanylmethyl)selenanylbenzo[b]furan
yellow oil; 1H-NMR (CDCl3, 400 MHz);
(ppm): 7.44–7.47 (m, 1H, Ar-H), 7.28–7.37 (m, 3H, Ar-H),
4.36–4.42 (m, 1H, O-CH), 4.18 (dd, J = 8.5 and 6.0 Hz, 1H, O- CH), 3.79 (dd, J = 8.5 and 6.0 Hz, 1H,
O- CH), 3.31 (dd, J = 12.3 and 5.2 Hz, 1H, Se- CH), 3.11 (dd, J = 12.3 and 7.8 Hz, 1H, Se- CH), 1.45 (s,
5 (Scheme 2): Yield: 0.093 g (85%);
δ
H
H
H
H
3H, C-CH3), 1.36 (s, 3H, C-CH3). 13C-NMR (CDCl3, 100 MHz);
δ (ppm): 156.7, 146.6, 131.3, 125.6, 123.6,
121.2, 111.0; 109.8; 75.8, 75.4; 69.1; 30.8, 27.0; 25.5. MS: m/z (rel. int.) 438 (M+, 23.4), 168 (18.2), 115 (35.3),
101 (21.5), 57 (100.0). HRMS: Calculated mass for C14H15IO3Se: [M + NH4]+ 455.9575, found: 455.9577.
4. Conclusions
In summary, we developed a new and general protocol to prepare glycerol-derived organoselanyl
and organotellanyl alkynes using tosyl solketal. Eight organoselanyl and five organotellanyl alkynes
were obtained in good yields and short reaction times, when compared to previously described

Molecules 2017, 22, 391
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procedures. Some of the organotellanyl alkynes were deprotected using Dowex 50WX8-(H+) to give
new water-soluble 3-organotellanylpropane-1,2-diols.
Supplementary Materials: Supplementary materials are available at http://www.mdpi.com/1420-3049/22/3/
391/s1.
Acknowledgments: The authors thank FAPERGS, CNPq and CAPES for financial support. CNPq is also
acknowledged for the fellowship for E.J.L., D.A. and G.P. This manuscript is part of the scientific activity of the
international multidisciplinary “SeS Redox and Catalysis” network.
Author Contributions: E.J.L. and G.P. conceived and designed the experiments; E.L.B., G.S. and L.K.S. performed
the experiments; D.A., R.F.S., L.B., F.M., E.J.L. and G.P. analyzed the data and wrote the paper.
Conflicts of Interest: The authors declared no conflict of interest.
References
1.
2.
3.
4.
5.
6.
7.
Wirth, T. Organoselenium Chemistry—Modern Developments in Organic Synthesis; Topics in Current Chemistry;
Springer: Heidelberg, Germany, 2000; Volume 208.
Zeni, G.; Lüdtke, D.S.; Panatieri, R.B.; Braga, A.L. Vinylic Tellurides: From Preparation to Their Applicability
in Organic Synthesis. Chem. Rev. 2006, 106, 1032–1076. [CrossRef] [PubMed]
Perin, G.; Lenardão, E.J.; Jacob, R.G.; Panatieri, R.B. Synthesis of Vinyl Selenides. Chem. Rev. 2009, 109,
1277–1301. [CrossRef] [PubMed]
Menezes, P.H.; Zeni, G. Vinyl Selenides in Patai’s Chemistry of Functional Groups; John Wiley & Sons: New York,
NY, USA, 2011.
Palomba, M.; Bagnoli, L.; Marini, F.; Santi, C.; Sancineto, L. Recent advances in the chemistry of
vinylchalcogenides. Phosphorus Sulfur Silicon Relat. Elem. 2016, 191, 235–244. [CrossRef]
Nogueira, C.W.; Rocha, J.B.T. Organoselenium and organotellurium compounds: Toxicology and
pharmacology. Chem. Rev. 2004, 104, 6255–6285. [CrossRef] [PubMed]
Goswami, S.; Hazra, A.; Chakrabarty, R.; Fun, H.-K. Recognition of carboxylate anions and carboxylic
acids by selenium-based new chromogenic fluorescent sensor: A remarkable fluorescence enhancement of
hindered carboxylates. Org. Lett. 2009, 11, 4350–4353. [CrossRef] [PubMed]
8.
9.
Rampon, D.S.; Rodembush, F.S.; Schneider, J.M.F.M.; Bechtold, I.H.; Gonçalves, P.F.B.; Merlo, A.A.;
Schneider, P.H. Novel selenoesters fluorescent liquid crystalline exhibiting a rich phase polymorphism.
J. Mater. Chem. 2010, 20, 715–722. [CrossRef]
Samb, I.; Bell, J.; Toullec, P.Y.; Michelet, V.; Leray, I. Fluorescent phosphane selenide as efficient mercury
chemodosimeter. Org. Lett. 2011, 13, 1182–1185. [CrossRef] [PubMed]
10. Mugesh, G.; du Mont, W.-W.; Sies, H. Chemistry of biologically important synthetic organoselenium
compounds. Chem. Rev. 2001, 101, 2125–2179. [CrossRef] [PubMed]
11. Santoro, S.; Azeredo, J.B.; Nascimento, V.; Sancineto, L.; Braga, A.L.; Santi, C. The green side of the moon:
Ecofriendly aspects of organoselenium chemistry. RSC Adv. 2014, 4, 31521–31535. [CrossRef]
12. Santi, C. Organoselenium Chemistry between Synthesis and Biochemistry, 1st ed.; Bentham eBooks: Perugia,
Italy, 2014.
13. Barcellos, A.M.; Abenante, L.; Sarro, M.T.; Leo, I.D.; Lenardão, E.J.; Perin, G.; Santi, C. New prospective for
redox modulation mediated by organoselenium and organotellurium compounds. Curr. Org. Chem. 2017, 21,
1–18. [CrossRef]
14. Pérez-Balado, C.; Markó, I.E. 1-Iodo-1-selenoalkenes as versatile alkene 1,1-dianion equivalents. Novel
connective approach towards the tetrahydropyran subunit of polycavernoside A. Tetrahedron 2006, 62,
2331–2349. [CrossRef]
15. Liu, C.-R.; Yang, F.-L.; Jin, Y.-Z.; Ma, X.-T.; Cheng, D.-J.; Li, N.; Tian, S.-K. Catalytic regioselective synthesis of
structurally diverse indene derivatives from n-benzylic sulfonamides and disubstituted alkynes. Org. Lett.
2010, 12, 3832–3835. [CrossRef] [PubMed]
16. Mitamura, T.; Ogawa, A. Palladium-catalyzed alkynylselenation of acetylenedicarboxylates leading to enyne
selenides and application to synthesis of multisubstituted aryl selenides. Tetrahedron Lett. 2010, 51, 3538–3541.
[CrossRef]

Molecules 2017, 22, 391
10 of 11
17. Okoronkwo, A.E.; Godoi, B.; Schumacher, R.F.; Neto, J.S.S.; Luchese, C.; Prigol, M.; Nogueira, C.W.; Zeni, G.
Csp3-tellurium copper cross-coupling: Synthesis of alkynyl tellurides a novel class of antidepressive-like
compounds. Tetrahedron Lett. 2009, 50, 909–915. [CrossRef]
18. Savegnago, L.; Borges, V.C.; Alves, D.; Jesse, C.R.; Rocha, J.B.T.; Nogueira, C.W. Evaluation of antioxidant
activity and potential toxicity of 1-buthyltelurenyl-2-methylthioheptene. Life Sci. 2006, 79, 1546–1552.
[CrossRef] [PubMed]
19. Ávila, D.S.; Gubert, P.; Palma, A.; Colle, D.; Alves, D.; Nogueira, C.W.; Rocha, J.B.T.; Soares, F.A.A.
An organotellurium compound with antioxidant activity against excitotoxic agents without neurotoxic
effects in brain of rats. Brain Res. Bull. 2008, 76, 114–123. [CrossRef] [PubMed]
20. Manarin, F.; Roehrs, J.A.; Gay, R.M.; Brandão, R.; Menezes, P.H.; Nogueira, C.W.; Zeni, G. Electrophilic
cyclization of 2-chalcogenealkynylanisoles: Versatile access to 2-chalcogen-benzo[b]furans. J. Org. Chem.
2009, 74, 2153–2162. [CrossRef] [PubMed]
21. Mantovani, A.C.; Back, D.F.; Zeni, G. Chalcogenoalkynes: Precursors for the regioselective preparation
of 2-chalcogeno-1-halonaphthalenes through [4 + 2] cycloaddition. Eur. J. Org. Chem. 2012, 4574–4579.
[CrossRef]
22. Lara, R.G.; Borges, E.L.; Lenardão, E.J.; Alves, D.; Jacob, R.G.; Perin, G. Addition of thiols to
phenylselenoalkynes using KF/alumina under solvent-free conditions. J. Braz. Chem. Soc. 2010, 21,
2125–2129. [CrossRef]
23. Perin, G.; Borges, E.L.; Alves, D. Highly stereoselective method to prepare bis-phenylchalcogen alkenes via
addition of chalcogenolate to phenylseleno alkynes. Tetrahedron Lett. 2012, 53, 2066–2069. [CrossRef]
24. Rampon, D.S.; Giovenardi, R.; Silva, T.L.; Rambo, R.S.; Merlo, A.A.; Schneider, P.H. Chalcogenoacetylenes
obtained by indium(III) catalysis: Dual catalytic activation of diorgano dichalcogenides and Csp-H bonds.
Eur. J. Org. Chem. 2011, 7066–7070. [CrossRef]
25. Godoi, M.; Ricardo, E.W.; Frizon, T.E.; Rocha, M.S.T.; Singh, D.; Paixão, M.W.; Braga, A.L. An efficient
synthesis of alkynyl selenides and tellurides from terminal acetylenes and diorganyl diselenides or
ditellurides catalyzed by recyclable copper oxide nanopowder. Tetrahedron 2012, 68, 10426–10430. [CrossRef]
26. Ahammed, S.; Bhadra, S.; Kundu, D.; Sreedhar, B.; Ranu, B.C. An efficient and general procedure for the
synthesis of alkynyl chalcogenides (selenides and tellurides) by alumina-supported Cu(II)-catalyzed reaction
of alkynyl bromides and diphenyl dichalcogenides. Tetrahedron 2012, 68, 10542–10549. [CrossRef]
27. Movasssagh, B.; Yousefi, A.; Momeni, B.Z.; Heydari, S. A general and highly efficient protocol for the
synthesis of chalcogenoacetylenes by copper(I)-terpyridine catalyst. Synlett 2014, 25, 1385–1390. [CrossRef]
28. Godoi, M.; Liz, D.G.; Ricardo, E.W.; Rocha, M.S.T.; Azeredo, J.B.; Braga, A.L. Magnetite (Fe3O4) nanoparticles:
An efficient and recoverable catalyst for the synthesis of alkynyl chalcogenides (selenides and tellurides)
from terminal acetylenes and diorganyl dichalcogenides. Tetrahedron 2014, 70, 3349–3354. [CrossRef]
29. Mohammadi, E. Movassagh, B. Cryptand-22 as an efficient ligand for the copper-catalyzed cross-coupling
reaction of diorgano dichalcogenides with terminal alkynes leading to the synthesis of alkynyl chalcogenides.
Tetrahedron Lett. 2014, 55, 1613–1615. [CrossRef]
30. Alves, D.; Sachini, M.; Jacob, R.G.; Lenardão, E.J.; Contreira, M.E.; Savegnago, L.; Perin, G. Synthesis of
(Z)-organylthioenynes using KF/Al2O3/solvent as recyclable system. Tetrahedron Lett. 2011, 52, 133–135.
[CrossRef]
31. Len, C.; Luque, R. Continuous flow transformations of glycerol to valuable products: An overview.
Sustain. Chem. Process. 2014, 2, 1–10. [CrossRef]
32. Mori, K. Pheromone synthesis. Part 253: Synthesis of the racemates and enantiomers of triglycerides of male
Drosophila fruit flies with special emphasis on the preparation of enantiomerically pure 1-monoglycerides.
Tetrahedron 2012, 68, 8441–8449. [CrossRef]
33. Manzo, E.; Ciavatta, M.L.; Pagano, D.; Fontana, A. An efficient and versatile chemical synthesis of bioactive
glyco-glycerolipids. Tetrahedron Lett. 2012, 53, 879–881. [CrossRef]
34. Wu, W.; Li, R.; Malladi, S.S.; Warshakoon, H.J.; Kimbrell, M.R.; Amolins, M.W.; Ukani, R.; Datta, A.;
David, S.A. Structure–activity relationships in toll-like receptor-2 agonistic diacylthioglycerol lipopeptides.
J. Med. Chem. 2010, 53, 3198–3213. [CrossRef] [PubMed]
35. Goubert, M.; Canet, I.; Sinibaldi, M.-E. An expedient route to new spiroheterocycles: Synthesis and structural
studies. Eur. J. Org. Chem. 2006, 4805–4812. [CrossRef]

Molecules 2017, 22, 391
11 of 11
36. Oh, K.; Yamada, K.; Asami, T.; Yoshizawa, Y. Synthesis of novel brassinosteroid biosynthesis inhibitors based
on the ketoconazole scaffold. Bioorg. Med. Chem. Lett. 2012, 22, 1625–1628. [CrossRef] [PubMed]
37. Gong, L.; Hirschfeld, D.; Tan, Y.-C.; Hogg, J.H.; Peltz, G.; Avnur, Z.; Dunten, P. Discovery of potent and
bioavailable GSK-3β inhibitors. Bioorg. Med. Chem. Lett. 2010, 20, 1693–1696. [CrossRef] [PubMed]
38. Perin, G.; Borges, E.L.; Duarte, J.E.G.; Webber, R.; Jacob, R.G.; Lenardão, E.J. Glycerol as renewable resource
in the synthesis of thioethers using KF/Al2O3. Curr. Green. Chem. 2014, 1, 115–120. [CrossRef]
39. Nobre, P.C.; Borges, E.L.; Silva, C.M.; Casaril, A.M.; Martinez, D.M.; Lenardão, E.J.; Alves, D.; Savegnago, L.;
Perin, G. Organochalcogen compounds from glycerol: Synthesis of new antioxidants. Bioorg. Med. Chem.
2014, 22, 6242–6249. [CrossRef] [PubMed]
40. Borges, E.L.; Peglow, T.J.; Silva, M.S.; Jacoby, C.G.; Schneider, P.H.; Lenardão, E.J.; Jacob, R.G.;
Perin, G. Synthesis of enantiomerically pure bis(2,2-dimethyl-1,3-dioxolanylmethyl)chalcogenides and
dichalcogenides. New J. Chem. 2016, 40, 2321–2326. [CrossRef]
41. Soares, L.K.; Silva, R.B.; Peglow, T.J.; Silva, M.S.; Jacob, R.G.; Alves, D.; Perin, G. Selective synthesis of
vinyl- or alkynyl chalcogenides from glycerol and their water-soluble derivatives. ChemistrySelect 2016, 1,
2009–2013. [CrossRef]
Sample Availability: Samples of the compounds 2–5 are available from the authors.
©
2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).