Highly stereoselective one-pot procedure to prepare bis- and tris-chalcogenide alkenes via addition of disulfides and diselenides to terminal alkynes

Article abstract of DOI:10.1021/jo050448o

We present here the reaction of diorganoyl dichalcogenides with terminal alkynes under catalyst-free conditions, by a one-pot procedure, to prepare bis- and tris-chalcogenide alkenes selectively, avoiding the previous preparation of chalcogen alkynes. The reaction proceeded cleanly under mild reaction conditions, and the addition of dichalcogenides to alkynes occurred stereoselectively to give exclusively the corresponding Z isomers. We observed that the selectivity control was governed by the effective participation of the hydroxyl group from propargyl alcohols. In addition, the bis-chalcogenide alkenes were exclusively obtained with propargyl alcohol having the acidic hydroxyl group proton. Conversely, the alkynes with no potentially acidic hydroxyl group proton, at propargyl positons, gave exclusively the tris-chalcogenide alkenes.

Full text of DOI:10.1021/jo050448o

Highly Stereoselective One-Pot Procedure To Prepare Bis- and
Tris-chalcogenide Alkenes via Addition of Disulfides and
Diselenides to Terminal Alkynes
Ange´lica Venturini Moro,† Cristina W. Nogueira,† Nilda B. V. Barbosa,†
Paulo Henrique Menezes,‡ Joa˜o Batista Teixeira da Rocha,† and Gilson Zeni*,†
Laborato´rio de Sı´ntese, Reatividade, Avaliac¸a˜o Farmacolo´gica e Toxicolo´gica de Organocalcogeˆnios,
CCNE, UFSM, Santa Maria, Rio Grande do Sul, Brazil 97105-900, and Departamento de Qu´ımica
Fundamental, UFPE, Recife, PE, Brazil 50670-901
gzeni@quimica.ufsm.br
Received March 8, 2005
We present here the reaction of diorganoyl dichalcogenides with terminal alkynes under catalyst-
free conditions, by a one-pot procedure, to prepare bis- and tris-chalcogenide alkenes selectively,
avoiding the previous preparation of chalcogen alkynes. The reaction proceeded cleanly under mild
reaction conditions, and the addition of dichalcogenides to alkynes occurred stereoselectively to
give exclusively the corresponding Z isomers. We observed that the selectivity control was governed
by the effective participation of the hydroxyl group from propargyl alcohols. In addition, the bis-
chalcogenide alkenes were exclusively obtained with propargyl alcohol having the acidic hydroxyl
group proton. Conversely, the alkynes with no potentially acidic hydroxyl group proton, at propargyl
positons, gave exclusively the tris-chalcogenide alkenes.
Introduction
tial and the fact that the chalcogen atom exercises a
stabilizing effect on neighboring positive as well as
negative charges. This makes the double bond in vinylic
chalcogenides responsive toward both nucleophilic and
electrophilic attack, an extremely useful feature for
organic synthetic purposes.
Organoselenium chemistry is a very broad and exciting
field, with many opportunities for research and develop-
ment of applications. Organoselenium compounds have
become attractive synthetic targets because of their
chemo-, regio-, and stereoselective reactions and their
useful biological activities.2 Furthermore, organoselenium
compounds can usually be used in a wide variety of
functional groups, thus avoiding protection group chem-
istry.3 Most organoselenium methodologies proceed ste-
reo- and regioselectively in excellent yields. Although the
In view of the fact that many biologically active
compounds have the structure of substituted alkenes, the
stereoselective synthesis of multifunctional alkenes is an
important goal in organic chemistry and is still being
actively explored. In the last few decades, there has been
remarkable interest in the synthesis of vinylic chalco-
genides and their synthetic application in the develop-
ment of methodologies for the synthesis of substituted
alkenes.1 There are several reasons for this, which
include a widely varied synthetic organochemical poten-
† UFSM.
‡ UFPE.
(1) (a) Silveira, C. C.; Perin, G.; Braga, A. L. Tetrahedron Lett. 1995,
36, 7361-7362. (b) Denis, J. N.; Desauvage, S.; Hevesi, L.; Krief, A.
Tetrahedron Lett. 1981, 22, 4009-4012. (c) Gerard, J.; Hevesi, L.
Tetrahedron 2001, 57, 9109-9121. (d) Zeni, G.; Alves, D.; Braga, A.
L.; Stefani, H. A.; Nogueira, C. W. Tetrahedron Lett. 2004, 45, 4823-
4826. (e) Zeni, G.; Alves, D.; Pena, J. M.; Braga, A. L.; Stefani, H. A.;
Nogueira, C. W. Org. Biomol. Chem. 2004, 2, 803-805. (f) Marino, J.
P.; Nguyen, H. N. J. Org. Chem. 2002, 67, 6291-6296. (g) Zeni, G.;
Stracke, M. P. Lissner, E.; Braga, A. L. Synlett 2003, 1880-1882.
(2) (a) Nogueira, C. W.; Zeni, G.; Rocha, J. B. T. Chem. Rev. 2004,
104, 6255-6286. (b) Mugesh, G.; du Mont, W. W.; Sies, H. Chem. Rev.
2001, 101, 2125-2180. (c) Parnham, M. J.; Graf, E. Prog. Drug Res.
1991, 36, 9-47. (d) Nogueira, C. W.; Quinhones, E. B.; Jung, E. A. C.;
Zeni, G.; Rocha, J. B. T. Inflammation Res. 2003, 52, 56-63.
10.1021/jo050448o CCC: $30.25 © 2005 American Chemical Society
Published on Web 05/25/2005
J. Org. Chem. 2005, 70, 5257-5268
5257

Moro et al.
SCHEME 1
first organoselenium compound was prepared by Wo¨hler
in 1847,4 only in the early 1970s did the chemistry of
organoselenium become a versatile tool in organic chem-
istry.5 Organoselenium chemistry developed rapidly,
mainly in the area of selenocarbohydrates, selenoamino
acids, and selenopeptides. The selenium group can be
introduced in an organic substrate via both nucleophilic
and electrophilic reagents. After being introduced in an
organic substrate, the organoselenium group can easily
be removed by selenoxide syn elimination6 and [2,3]
sigmatropic rearrangement.7 In addition, the carbon-
selenium bond can also be replaced by a carbon-
hydrogen,8 carbon-halogen,9 carbon-lithium,10 or carbon-
carbon bond.11
Among organoselenium compounds, the vinylic
selenides play an important role in organic synthesis.
Although various methods are mentioned for the prepa-
ration of vinylic selenides, a more useful procedure has
centered on the nucleophilic or electrophilic organo-
selenium addition to terminal or internal alkynes.12 For
example, the nucleophilic addition of selenophenol to
alkynes affords, preferentially, the Z-vinylic selenides
after longer reaction times at room temperature. The
reaction is faster at a high temperature; however, the
mixture of Z and E vinylic selenides was obtained in an
almost 1:1 ratio (Scheme 1).13 On the other hand, the
eletrophilic addition of organoselenenyl halides to alkynes
gave a mixture of Markownikov and anti-Markownikov
adducts, depending on the nature of the substituents at
the triple bond (Scheme 1).14 Conversely, vinylic selenides
can be prepared by palladium-catalyzed hydroselenation
of alkynes to afford the Markownikov adduct in good
yields.15
In addition to organoselenium, the scope and applica-
tion of organosulfur chemistry has increased tremen-
dously since sulfur-containing groups serve an important
auxiliary function in synthetic sequences. The application
of organosulfur compounds in organic synthesis has
become attractive because of their chemio-, regio-, and
stereoselective reactions. Most of the synthetic trans-
formations using organosulfur compounds have involved
the use of vinylic sulfides.16 Many procedures for the
preparation of vinyl sulfides have been developed. Among
them, the regioselective addition of hydrogen halide (HCl,
HBr, HI) to acetylenic sulfides was the most simple and
efficient.17 Although the regioselectivity of the addition
of hydrogen halide to acetylenic sulfides was excellent,
it often resulted in the formation of both Z- and E-isomers
due to use of excess aqueous hydrogen halide (37% HCl,
48% HBr, or 51% HI) or saturated gaseous HX in
benzene. Moreover, the separation of the Z- and E-
isomers was often quite difficult. Therefore, a new
procedure is needed for the stereoselective synthesis of
vinyl sulfides. In this way, both alkyl and aryl thiols have
been shown to add regio- and stereoselectivity to alkynes
to give vinyl sulfides. With activated alkynes such as
acetylenic esters and ketones, the addition has been
performed under basic conditions, using reagents such
as KOH18 and triethylamine.19 However, for unactivated
alkynes, the use of radical initiators,20 transition-metal
catalysts,21 and high temperatures22 has been required.
Our continuing interest in the synthesis23 and applica-
tion24 of vinylic chalcogenides in organic synthesis
prompted us to examine a one-pot procedure to prepare
a series of bis-chalcogenide alkenes 2 and tris-chalco-
genide alkenes 3 by the reaction of diorganoyl dichalco-
(3) (a) Nicolaou, K. C.; Petasis, N. A. Selenium in Natural Products
Synthesis; CIS: Philadelphia, 1984. (b) Paulmier, C. Selenium Reagents
and Intermediates in Organic Synthesis; Pergamon: Oxford, 1986. (c)
Patai, S.; Rappoport, Z. The Chemistry of Organic Selenium and
Tellurium Compounds; Wiley: New York, 1986; Vol 1. (d) Liotta, D.
Organoselenium Chemistry; Wiley: New York, 1987. (e) Krief, A.;
Hevesi, L. Organoselenium Chemistry I; Springer: Berlin, 1988. (f)
Back, T. G. Organoselenium Chemistry: A Pratical Approach; Oxford
University Press: Oxford, 1999. (g) Reich, H. J. Acc. Chem. Res. 1979,
12, 22-30. (h) Liotta, D. Acc. Chem. Res. 1984, 17, 28-34. (i) Wirth,
T. Organoselenium ChemistrysModern Developments in Organic
Synthesis. Top. Curr. Chem. 208; Spring-Verlag: Heidelberg, 2000.
(j) Mugesh, G.; Singh, H. B. Acc. Chem. Res. 2002, 35, 226-236.
(4) Wo¨hler, F.; Siemens, C. Ann. Chem. 1847, 61, 360-365.
(5) Sharpless, K. B.; Lauer, R. F. J. Am. Chem. Soc. 1973, 95, 2697-
2699.
(6) (a) Huguet, J. L. Adv. Chem. Ser. 1967, 345-348. (b) Sharpless,
K. B.; Young, M. W.; Lauer, R. F. Tetrahedron Lett. 1973, 22, 1979-
1982.
(7) (a) Reich, H. J. J. Org. Chem. 1975, 40, 2570-2572. (b) Sharpless,
K. B.; Lauer, R. F. J. Am. Chem. Soc. 1972, 94, 7154-7155.
(8) Sevrin, M.; Vanende, D.; Krief, A. Tetrahedron Lett. 1976, 30,
2643-2646.
(9) Sevrin, M.; Dumont, W.; Hevesi, L. D.; Krief, A. Tetrahedron Lett.
1976, 30, 2647-2650.
(15) Kuniyasu, H.; Ogawa, A.; Sato, K. I.; Ryu, I.; Sonoda, N.
Tetrahedron Lett. 1992, 33, 5525-5528.
(16) For the synthetic utility of vinyl sulfides, see, for example: (a)
Ager, D. J. Chem. Soc. Rev. 1982, 11, 493-522. (b) Takeda, T.;
Furukawa, H.; Fujimori, M.; Suzuki, K.; Fujiwara, T. Bull. Chem. Soc.
Jpn. 1984, 57, 1863-1869. (c) Gro¨bel, B.-T.; Seebach, D. Synthesis
1977, 357-402. (d) Trost, B. M.; Lavoie, A. C. J. Am. Chem. Soc. 1983,
105, 5075-5090. (e) Magnus, P.; Quagliato, D. J. Org. Chem. 1985,
50, 0, 1621-1626. (f) Delucchi, O.; Pasquato, L. Tetrahedron 1988, 44,
6755-6794. (g) Pettit, G. R.; van Tamelen, E. E. Org. React. 1962, 12,
356-363. (h) Boar, R. B.; Hawkins, D. W.; McGhie, J. F.; Barton, D.
H. R. J. Chem. Soc., Perkin Trans. 1 1973, 654-657. (i) Trost, B. M.;
Ornstein, P. L. Tetrahedron Lett. 1981, 22, 3463-3466. (j) Wenkert,
E.; Ferreira, T. W. J. Chem. Soc., Chem. Commun. 1982, 840-841.
(k) Hojo, M.; Tanimoto, S. J. Chem. Soc., Chem. Commun. 1990, 1284-
1285. (l) Hojo, M.; Harada, H.; Yoshizawa, J.; Hosomi, A. J. Org. Chem.
1993, 58, 6541-6542.
(10) (a) Seebach, D.; Peleties, N. Chem. Ber. 1972, 105, 511-515.
(b) Seebach, D.; Beck, A. K. Angew. Chem., Int. Ed. Engl. 1974, 13,
806-807. (c) Reich, H. J.; Shah, S. K. J. Am. Chem. Soc. 1975, 97,
3250-3252.
(11) Silveira, C. C.; Braga, A. L.; Vieira, A. S.; Zeni, G. J. Org. Chem.
2003, 68, 662-665.
(12) (a) Comasseto, J. V. J. Organomet. Chem. 1983, 253, 131-181.
(b) Barros, O. S. D.; Lang, E. S.; de Oliveira, C. A. F.; Peppe, C.; Zeni,
G. Tetrahedron Lett. 2002, 43, 7921-7923. (c) Dabdoub, M. J.;
Dabdoub, V. B.; Pereira, M. A. Tetrahedron Lett. 2001, 42, 1595-1597.
(d) Dabdoub, M. J.; Baroni, A. C. M.; Lenarda˜o, E. J.; Gianeti, T. R.;
Hurtado, G. R. Tetrahedron 2001, 57, 4271-4276. (e) Dabdoub, M. J.;
Cassol, T. M.; Batista, A. C. F. Tetrahedron Lett. 1996, 37, 9005-9008.
(13) Comasseto, J. V.; Ferreira, J. T. B. J. Organomet. Chem. 1981,
216, 287-294.
(17) Comasseto, J. V.; Menezes, P. H.; Stefani, H. A.; Zeni, G.; Braga,
A. L. Tetrahedron 1996, 52, 9687-9702.
(18) (a) Wadsworth, D. H.; Detty, M. R. J. Org. Chem. 1980, 45,
4611-4615. (b) Kobayashi, S.; Mukaiyama, T. Chem. Lett. 1974, 705-
708.
(14) (a) Filer, C. N.; Ahern, D.; Fazio, R.; Shelton, E. J. J. Org. Chem.
1980, 45, 1313-1315. (b) Garratt, D. G.; Beaulieu, P. L.; Morisset, U.
M. Can. J. Chem. 1981, 59, 927-934.
(19) Dieter, R. K.; Silks, L. A., III; Fishpaugh, J. R.; Kastner, M. E.
J. Am. Chem. Soc. 1985, 107, 4679-4692.
5258 J. Org. Chem., Vol. 70, No. 13, 2005

Preparation of Bis- and Tris-chalcogenide Alkenes
SCHEME 2
entry 4). Taken in analogy with the hydrotelluration
reactions, which lead to a Z-alkene exclusively, in which
the tellurolate anion and the hydrogen are known to add
to the alkyne in a trans-fashion and the proton is believed
to come from the hydroxyl group of ethanol,23a,b we
applied this finding by choosing EtOH as a proton source.
Nonetheless, performing the reaction in the presence of
EtOH at room temperature for 12 h and 74 °C for 3 h
gave unsatisfactory results (Table 1, entries 5 and 6),
whereas the use of 74 °C for 12 h increased the yield to
90% (Table 1, entry 7). Replacement of EtOH with H2O
or AcOH was inefficient to obtain better results, even
under conditions of high temperature and a long reaction
time (Table 1, entries 8 and 9). Thus, careful analysis of
the optimized reactions revealed that the optimum condi-
tions for this one- pot procedure were the addition of
n-butyllithium (2.1 mmol) to a solution of 2-methylbut-
3-yn-2-ol (1 mmol) and THF (2 mL), at 0 °C. Then, after
30 min at room temperature, dimethyl disulfide (1.2
mmol) was added. The reaction was stirred for 3 h; after
that, EtOH (0.5 mL) was added. The mixture was heated
at 74 °C for 12 h. Using these reaction conditions, we
were able to prepare Z-vinylic sulfide 2m in 90% yield.
To demonstrate the efficiency of this reaction, we ex-
plored the generality of our method extending the condi-
tions to various propargyl alcohols as well as other
aromatic and aliphatic disulfides, and the results are
summarized in Table 2.
TABLE 1. Investigation of the Best Reaction
Conditions
entry
cosolvent
T (°C)
time (h)
yield (%)
1
2
3
4
5
6
7
8
9
25
74
74
74
25
74
74
74
74
3
3
12
36
12
3
12
12
12
NR
20
31
48
5
54
90
13
28
EtOH
EtOH
EtOH
AcOH
H2O
genides with terminal alkynes 1, under catalyst-free
conditions (Scheme 2).
Inspection of Table 2 shows that the reaction worked
well for a variety of propargylic alcohols. Both hindered
and nonhindered propargyl alcohols gave the desired
sulfide in good yields. A closer inspection of the results
revealed that the reaction is sensitive to the position of
substituents in aromatic disulfides. For example, diphen-
yl disulfides with a Cl substituent at the meta position
gave a worse yield than at the ortho and para positions
(Table 2, entries 4-6). Diphenyl disulfides with a NO2
or NH2 group at the para position did not react under
our standard conditions, even after many modifications
(change in the base, amount of disulfide, solvent, cosol-
vents, temperature, and time) (Table 2, entries 7 and 8).
These results demonstrated that the efficiency of the
vinyl sulfide formations could significantly depend on the
electronic effects of the substituents in the aromatic ring.
The vinyl sulfide formation was low in the cases where
benzylic and long-chain aliphatic disulfide were employed
(Table 2, entries 9 and 10), probably due to the steric
effect of these groups. Based on the above results, it is
noteworthy that the vinyl sulfide formation was not
sensitive to the structure of propargyl alcohols; however,
it was dependent on the nature of disulfides.
In an attempt to broaden the scope of our methodology,
the possibility of performing the reaction with diselenides
instead of disulfides was also investigated. Thus, the
standard reaction condition applied to prepare the vinyl
sulfides was also tested for diselenides. In this way,
n-butyllithium (2.1 mmol) was added to a solution of
propargyl alcohol (1 mmol) and THF (2 mL), at 0 °C, and
after 30 min at room temperature, diselenide (1.2 mmol)
was added at 0 °C. The reaction was stirred for 3 h, after
which time EtOH (0.5 mL) was added. The mixture was
heated at 74 °C at 12 h. The scope and limitations of the
diselenide addition to propargyl alcohol are summarized
in Table 3.
Results and Discussion
Since our initial studies have focused on the develop-
ment of an optimum set of reaction conditions, we have
initially chosen 2-methylbut-3-yn-2-ol and dimethyl di-
sulfide as standard starting materials. In this way,
n-butyllithium (2.1 mmol) was added, at 0 °C, to a
solution of the 2-methylbut-3-yn-2-ol (1 mmol) and THF
(2 mL), and after 30 min, the dimethyl disulfide was
added at 0 °C. The results of the reactions with a variety
in temperature, time, and addition of a cosolvent are
summarized in Table 1.
As shown in Table 1, the reaction of 2-methylbut-3-
yn-2-ol with dimethyl disulfide at room temperature for
3 h did not afford the desired vinyl sulfide 2m (Table 1,
entry 1). When the temperature is changed to 74 °C, the
reaction resulted in a low yield after 3 h (Table 1, entry
2). Furthermore, if the heating (74 °C) was continued for
12 h, vinyl sulfide 2m was obtained in 31% yield (Table
1, entry 3). We also observed that a higher reaction time
(36 h) did not significantly improve the yield (Table 1,
(20) (a) Galambos, G.; Csokasi, P.; Szantay, C. J.; Czira, G.; Szantay,
C. Heterocycles 1994, 38, 1459-1464. (b) Montevecchi, P. C.; Navacchia,
M. L. Tetrahedron Lett. 1998, 39, 9077-9080.
(21) (a) Kuniyasu, H.; Ogawa, A.; Sato, K. I.; Kambe, N.; Sonoda,
N. J. Am. Chem. Soc. 1992, 114, 5902-5903. (b) Ishino, Y.; Masaoka,
T.; Hirashima, T. Chem. Lett. 1990, 7, 1185-1188. (c) Ogawa, A.; Ikeda,
T.; Kimura, K.; Hirao, T. J. Am. Chem. Soc. 1999, 121, 5108-5114.
(d) Ogawa, A.; Kudo, A.; Hirao. T. Tetrahedron Lett. 1998, 39, 5213-
5216.
(22) Benati, L.; Montevecchi, P. C.; Spagnolo, P. J. Chem. Soc.,
Perkin Trans. 1 1991, 9, 2103-2109.
(23) (a) Zeni, G.; Stracke, M. P.; Nogueira, C. W.; Braga, A. L.;
Menezes, P. H.; Stefani, H. A. Org. Lett. 2004, 6, 1135-1138. (b) Zeni,
G.; Barros, O. S. D.; Moro, A. V.; Braga, A. L.; Peppe, C. Chem.
Commun. 2003, 1258-1259. (c) Barros, O. S. D.; Lang, E. S.; Peppe,
C.; Zeni, G. Synlett 2003, 1725-1727.
(24) (a) Zeni, G.; Braga, A. L.; Stefani, H. A. Acc. Chem. Res. 2003,
36, 731-738. (b) Zeni, G.; Panatieri, R. B.; Lissner, E.; Menezes, P.
H.; Braga, A. L.; Stefani, H. A. Org. Lett. 2001, 3, 819-821.
J. Org. Chem, Vol. 70, No. 13, 2005 5259

Moro et al.
TABLE 2. Vinyl Sulfides Prepared from Alkynes and Disulfides
5260 J. Org. Chem., Vol. 70, No. 13, 2005

Preparation of Bis- and Tris-chalcogenide Alkenes
Table 2 (Continued)
Our first investigations focused on the influence of
alkyl substituents at the propargyl position. Satisfacto-
rily, all propargyl alcohols were found to be effective,
although very poor yields were observed in more hindred
propargyl alcohols (Table 3, entries 1, 8, and 9). Next,
several diselenides having different substituents were
tested. As shown in entry 2, bulky aryl diselenides
afforded the vinylic selenide 2s in excellent yield. Our
experiments showed that the reaction with diphenyl
diselenides having either neutral (entry 1), electron-
donating (entry 3), or electron-withdrawing (entry 4)
substituents also gave the vinylic selenides in good yields,
although the yield was lower for the electron-withdraw-
ing substituent (entry 4). Based on these results, we
conclude that the reactivity order in the formation of
vinylic selenides, considering the aromatic substituents
in diselenides, is H > MeO > Cl. However, no significant
influence of the substituents at the propargyl position
in propargyl alcohol was observed. On the other hand,
considerable difficulties were found when we attempted
to react aliphatic diselenides with propargyl alcohol,
where we observed that many byproducts were formed
and the desired product was obtained in lower yields. For
example, a small amount of vinylic selenides was isolated
from the reaction of dimethyl diselenide, di-n-butyl
diselenide, or di-tert-butyl diselenide with propargyl
alcohols (entries 5-7).
A plausible mechanism for the formation of vinylic
sulfides 2a-q and selenides 2r-z is shown in Scheme
3. We believe that (a) the removal of acid hydrogens
with n-BuLi from propargyl alcohols gave the lithium
intermediate a and the reaction of a with dichalco-
genide afforded the species b; (b) the addition of
EtOH led to the protonation of the intermediate b
to give the acetylenic chalcogenide c; (c) starting the
reflux led to the addition of the chalcogenate anion
onto the triple bond of the acetylenic chalcogenide c
and the subsequent trapping of the vinyl anion with a
proton from the acidic proton of the hydroxyl group,
according to transition state d, leads to the desired vinyl
compounds (Scheme 3). Here, different from our previous
work,23a we have found that vinylic hydrogen came from
hydroxyl group of propargyl alcohols. Thus, we believe
that the presence of EtOH is required due to poor
solubility of the intermediate b rather than as a proton
source.
J. Org. Chem, Vol. 70, No. 13, 2005 5261

Moro et al.
TABLE 3. Vinyl Selenides Prepared from Propargyl Alcohols and Diselenides
Although the intermediate b could not be isolated from
this reaction, several considerations and additional ob-
servations support the mechanism described in Scheme
3. First, when the reaction was stopped before starting
the reflux (3 h at room temperature), a careful NMR
analysis of the crude reaction mixture revealed the
presence of acetylenic chalcogenide c as a major product.
Second, when we carried out the addition of dimethyl
disulfide to pent-1-yn-3-ol in MeOH-d4, vinylic sulfide 4
was isolated as the sole product (Scheme 4). Finally,
5262 J. Org. Chem., Vol. 70, No. 13, 2005

Preparation of Bis- and Tris-chalcogenide Alkenes
SCHEME 3
SCHEME 4
SCHEME 5
when the reaction was repeated with dimethyl disulfide
and propargyl ether, without an acidic proton in the
hydroxyl group, unexpectedly, tris-phenylthioalkene 3e
was obtained, instead of bis-phenylthioalkene 5 (Scheme
5). These results strongly suggest that the addition of
dichalcogenides across the triple bond follows an anti-
pathway addition, with the effective participation of the
hydroxyl group from propargyl alcohols.
was observed with alkynes bearing a t-Bu or n-Bu group
(Table 4, entries 3 and 4). The use of a long chain alcohol
also failed to produce the desired product (Table 4, entry
14). However, checking Table 4, we observed that the
reaction worked well with hindered and nonhindered
protected propargylic alcohols, tertiary propargylamines,
and propargyl morpholynes. Regarding diselenides and
disulfides, dialkyl disulfides and diaryl diselenides af-
forded tris-vinylic chalcogenides in good yields, although
the yield was lower to diaryl diselenides, both electron-
withdrawing and electron-rich (Table 4, entries 7 and 8).
Finally, it is worth mentioning that, through our meth-
odology, it was possible to prepare highly functionalized
chalcogene alkenes, such as 3o and 3p (Table 4, entries
15 and 16).
In all cases where no desired vinyl chalcogenide was
formed, we recovered a small amount of dichalcogenide
and observed the formation of a large amount of alkynyl
chalcogenide. The latter product was presumably formed
by the known reaction of n-BuLi with alkynes and the
trapping of the lithium intermediate with disulfide as an
electrophilic reagent (Scheme 6).17
The reaction pathways leading to tris-chalcogen alkene
h products seem to depend on the amount of dichalco-
genides present in the reaction (1.2 and 2.2 mmol of
dichalcogenides gave poor yields) and the absence of the
potentially acidic hydroxyl group protons in the structure
of alkynes. Thus, the removal of acid hydrogens with
n-BuLi from alkynes gave lithium intermediate e and the
reaction of this intermediate with dichalcogenide afforded
acetylenic chalcogenide f together with lithium chalco-
genate. Starting the reflux led to the addition of the
chalcogenate anion onto the triple bond of acetylenic
chalcogenide f, with concomitant attack on the dichalco-
Based on the surprising results above, we initiated our
investigations in the preparation of these compounds via
reaction of dichalcogenides with alkynes in a one-pot
procedure. At first, the reaction was carried out using
the standard reaction conditions applied to prepare bis-
chalcogen alkenes. Unfortunately, this condition was not
effective, and tris-chalcogen alkenes were obtained only
in a moderate yield. The use of other solvents such as
benzene, hexane, ethyl ether, and toluene also failed to
produce the chalcogenide in a satisfactory yield. However,
it was gratifying to discover that simply changing the
amount of disulfide from 1.2 to 3 mmol and performing
the reaction in the absence of ethanol had a dramatic
effect, giving tris-chalcogen alkene 3e in 89% yield. Thus,
careful analysis of the optimized reactions revealed that
the general synthetic procedure for the reaction is as
follows: n-butyllithium (1.1 mmol) is added to a solution
of alkyne (1 mmol) and THF (2 mL), at 0 °C. The
resulting solution is stirred for 30 min at room temper-
ature. After that, dichalcogenide is added and the mix-
ture is then heated at 74 °C for 12 h. Next, we extended
our studies on the scope of the addition of disulfides and
diselenides to different alkynes, and the results are
summarized in Table 4.
Concerning the structure of alkynes, we found some
limitations in this methodology. For example, no reaction
J. Org. Chem, Vol. 70, No. 13, 2005 5263

Moro et al.
TABLE 4. Tris-chalcogen Alkenes Prepared from Alkynes and Dichalcogenides
5264 J. Org. Chem., Vol. 70, No. 13, 2005

Preparation of Bis- and Tris-chalcogenide Alkenes
Table 4 (Continued)
SCHEME 6
regenerated the starting materials, ditelurides, and
alkynes (Scheme 9).12c,23a
1
Analysis of the H and 13C NMR spectra showed that
both bis-vinylic chalcogenides 2a-z and tris-vinylic chal-
cogenides 3a-p presented data in full agreement with
their assigned structures. The stereochemistry of these
substituted alkenes was established by NOE experi-
ments. For example, when compound 2k was irradiated
at the signal attributed to vinylic hydrogen (6.51 ppm),
an enhancement of allylic hydrogens (4.10 ppm) was
observed, showing a cis relation between them. The
results have shown that the addition of dichalcogenides
to alkynes occurs stereoselectively to give exclusively the
corresponding Z isomers.
genides, according to transition state g, leading to the
desired vinyl compounds (Scheme 7).
Finally, we completed our investigations by examining
the reaction of diorganoyl ditellurides with terminal
alkynes, and we found that when this reaction was
carried out under experimental conditions, similar to
those used for the preparation of bis-2a-z and tris-3a-
p, neither vinylic telluride 6 nor 7 was obtained. In an
attempt to obtain these compounds, a variety of condi-
tions were investigated, including temperature, solvent,
stoichiometry, alkynes, and ditellurides. Unfortunately,
all conditions tested were found to be ineffective, and
neither bis-arganoyltelluride alkene 6 nor tris-arganoyl-
telluride alkene 7 was obtained (Scheme 8). In these
cases, we recovered alkyne and ditelluride as products.
Based on these results and with the knowledge that the
carbon-tellurium bond exhibits an easier heterolytic
cleavage toward nucleophilic reagents than the carbon-
sulfur and carbon-selenium bonds, due to the large
volume and greater ionic character of the tellurium atom
and the easy polarization of the bonds, we assumed that
alkynyl telluride was formed as an intermediate. How-
ever, a direct attack of RTeLi to the heteroatom (Te)
Conclusion
In summary, we present here the first chalcogenation
reaction of alkynes by a one-pot procedure to selectively
prepare bis-vinylic chalcogenides and tris-vinylic chal-
cogenides, avoiding the previous preparation of chalcogen
alkynes. We observed that the selectivity control was
governed by the effective participation of the hydroxyl
group from propargyl alcohols. In addition, bis-vinylic
chalcogenides were exclusively obtained with propargyl
alcohol containing acidic hydroxyl group protons. Con-
J. Org. Chem, Vol. 70, No. 13, 2005 5265

Moro et al.
SCHEME 7
129.9, 129.8, 129.2, 129.1, 127.3, 126.9, 65.3. MS (EI, 70 eV)
m/z (relative intensity): 274 (100), 186 (10), 167 (43), 147 (27),
135 (52), 91 (14), 77 (5). HRMS: calcd for C15H14OS2 274.0486,
found 274.0491.
(Z)-2,3-Bis(4-methoxyphenylthio)prop-2-en-1-ol (2c).
Yield: 0.264 g (79%). 1H NMR, CDCl3, 400 MHz, δ (ppm):
7.38-7.35 (m, 4H), 6.86-6.81 (m, 4H), 6.72 (s, 1H), 4.02 (s,
2H), 3.77-3.75 (m, 6H), 2.15 (m, 1H). 13C NMR, CDCl3, 100
MHz, δ (ppm): 159.4, 159.3, 133.2, 132.9, 132.9, 130.3, 125.3,
123.1, 114.7, 114.7, 64.9, 55.3, 55.2. MS (EI, 70 eV) m/z
(relative intensity): 333 (1), 318 (91), 227 (95), 179 (90), 164
(100), 139 (85), 96 (25), 77 (10). HRMS: calcd for C17H18O3S2
334.0697, found 334.0703.
SCHEME 8
SCHEME 9
(Z)-2,3-Bis(4-chlorophenylthio)prop-2-en-1-ol
(2d).
Yield: 0.215 g (63%). 1H NMR, CDCl3, 400 MHz, δ (ppm):
7.38-7.26 (m, 8H), 6.97 (t, J ) 1.17 Hz, 1H), 4.15 (d, J ) 5.11
Hz, 2H), 1.85 (t, J ) 5.55 Hz, 1H). 13C NMR, CDCl3, 100 MHz,
δ (ppm): 134.6, 133.8, 133.2, 133.1, 131.8, 131.6, 131.1, 130.1,
129.4, 129.4, 65.4. MS (EI, 70 eV) m/z (relative intensity): 257
(9), 168 (20), 111 (15), 97 (26), 83 (34), 69 (51), 67 (73), 55 (100).
HRMS: calcd for C15H12Cl2OS2 341.9706, found 341.9712.
versely, alkynes with no potentially acidic hydroxyl group
protons, at propargyl positons, gave exclusively tris-
vinylic chalcogenides. We hope that these findings will
be useful to assist in choosing a method for the chalco-
genation of alkynes containing different functional groups.
This reaction, associated with the Ni/CuI-catalyzed cross-
coupling reaction of vinylic selenides11 with alkynes, may
constitute an interesting alternative route to the regio-
and stereoselective preparation of functionalized alkenes.
The pharmacological activity of these compounds is under
study in our laboratory.
(Z)-2,3-Bis(3-chlorophenylthio)prop-2-en-1-ol
Yield: 0.202 g (59%). 1H NMR, CDCl3, 400 MHz, δ (ppm):
7.43-7.19 (m, 8H), 7.07 (s, 1H), 4.19 (s, 2H), 1.93 (s, 1H). 13
NMR, CDCl3, 100 MHz, δ (ppm): 136.4, 135.2, 135.0, 134.8,
134.5, 130.3, 130.2, 130.0, 129.9, 128.9, 128.3, 127.7, 127.4,
127.1, 65.5. MS (EI, 70 eV) m/z (relative intensity): 341 (3),
222 (100), 178 (23), 161 (11), 143 (6). HRMS: calcd for C15H12-
Cl2OS2 341.9707, found 341.9714.
(2e).
C
(Z)-2,3-Bis(2-chlorophenylthio)prop-2-en-1-ol
(2f).
Yield: 0.274 g (80%). 1H NMR, CDCl3, 400 MHz, δ (ppm):
7.49-7.47 (m, 1H), 7.42-7.33 (m, 3H), 7.27-7.13 (m, 4H), 7.06
(s, 1H), 4.17 (s, 2H), 2.12 (s, 1H). 13C NMR, CDCl3, 100 MHz,
δ (ppm): 135.0, 134.3, 134.1, 133.6, 132.2, 131.6, 130.4, 130.1,
130.0, 129.8, 128.6, 127.7, 127.4, 127.3, 65.5. MS (EI, 70 eV)
m/z (relative intensity): 342 (1), 326 (66), 291 (24), 235 (100),
183 (30), 148 (98), 108 (86), 69 (31). HRMS: calcd for C15H12-
Cl2OS2 341.9706, found 341.9814.
Experimental Section
General Procedure for the Preparation of the Bis-
chalcogenide Alkenes. n-Butyllithium (1.34 mL of a 1.567
M solution in hexane, 2.1 mmol) was added, under argon, to a
solution of alkyne (1 mmol) in THF (2 mL) previously cooled
at 0 °C. The resulting solution was stirred for 30 min at room
temperature. After this time, the mixture was cooled at 0 °C,
and the disulfide or diselenide (1.2 mmol) in THF (1 mL) was
added. The reaction was warmed at room temperature, stirred
for 3 h, and then treated with ethanol (0.5 mL). The mixture
was then heated at reflux for 12 h. After this time, the mixture
was cooled at room temperature, diluted with ethyl acetate
(20 mL), and washed with brine (2 × 20 mL). The organic
phase was separated, dried over MgSO4, and concentrated
under vacuum. The residue was purified by flash chromatog-
raphy and eluted with hexane/ethyl acetate (80:20). (Z)-2,3-
Bis(methylthio)prop-2-en-1-ol (2a). Yield: 0.147 g (98%).
1H NMR, CDCl3, 400 MHz, δ (ppm): 6.40 (s, 1H), 4.21 (s, 2H),
2.35 (s, 3H), 2.32 (s, 3H), 2.16 (s, 1H). 13C NMR, CDCl3, 100
MHz, δ (ppm): 130.8, 130.4, 64.8, 16.9, 14.3. MS (EI, 70 eV)
m/z (relative intensity): 151 (7), 121 (100), 103 (14), 73 (14),
59 (40), 47 (13). HRMS: calcd for C5H10OS2 150.0173, found
150.0178.
(Z)-2,3-Bis(benzylthio)prop-2-en-1-ol (2i). Yield: 0.157
1
g (52%). H NMR, CDCl3, 400 MHz, δ (ppm): 7.30-7.17 (m,
10H), 6.51 (s, 1H), 3.92 (s, 2H), 3.90 (s, 2H), 3.87 (s, 2H), 1.81
(s, 1H). 13C NMR, CDCl3, 100 MHz, δ (ppm): 137.9, 137.6,
132.6, 129.5, 128.7, 128.7, 128.6, 128.3, 127.2, 127.0, 66.2, 37.7,
35.8. MS (EI, 70 eV) m/z (relative intensity): 284 (33), 162
(100), 147 (17), 128 (50), 115 (25), 91 (38). HRMS: calcd for
C17H18OS2 302.0799, found 302.0805.
(Z)-2,3-Bis(dodecylthio)prop-2-en-1-ol (2j). Yield: 0.247
g (54%). 1H NMR, CDCl3, 400 MHz, δ (ppm): 6.51 (s, 1H), 4.17
(s, 2H), 2.77-2.70 (m, 4H), 1.66-1.55 (m, 4H), 1.39-1.26 (m,
36H), 0.88 (t, J ) 7.02 Hz, 6H). 13C NMR, CDCl3, 100 MHz, δ
(ppm): 132.3, 129.3, 65.8, 34.1, 34.1, 31.9, 31.9, 31.7, 31.7, 30.4,
30.0, 29.63, 29.62, 29.61, 29.58, 29.57, 29.51, 29.5, 29.3, 29.25,
29.2, 28.8, 28.6, 22.7, 22.7, 14.1, 14.1. MS (EI, 70 eV) m/z
(relative intensity): 458 (3), 257 (97), 240 (35), 227 (39), 199
(90), 87 (100), 59 (70). HRMS: calcd for C27H54OS2 458.3616,
found 458.3621.
(Z)-2,3-Bis(phenylthio)prop-2-en-1-ol (2b). Yield: 0.219
1
g (80%). H NMR, CDCl3, 400 MHz, δ (ppm): 7.44-7.19 (m,
10H), 7.01 (t, J ) 1.02 Hz, 1H), 4.12 (s, 2H), 2.15 (s, 1H). 13C
NMR, CDCl3, 100 MHz, δ (ppm): 134.8, 134.5, 133.1, 130.3,
(Z)-1,2-Bis(methylthio)pent-1-en-3-ol (2k). Yield: 0.172
g (97%). 1H NMR, CDCl3, 400 MHz, δ (ppm): 6.52 (s, 1H), 4.10
5266 J. Org. Chem., Vol. 70, No. 13, 2005

Preparation of Bis- and Tris-chalcogenide Alkenes
(t, J ) 6.28 Hz, 1H), 2.48 (s, 1H), 2.35 (s, 3H), 2.29 (s, 3H),
1.77-1.57 (m, 2H), 0.91 (t, J ) 7.45 Hz, 3H). 13C NMR, CDCl3,
100 MHz, δ (ppm): 134.6, 132.8, 76.8, 28.7, 16.7, 15.9, 9.8.
MS (EI, 70 eV) m/z (relative intensity): 160 (100), 145 (80),
130 (7), 112 (5), 97 (52). HRMS: calcd for C7H14OS2 178.0486,
found 178.0490.
(Z)-2,3-Bis(4-methoxyphenylselanyl)prop-2-en-1-ol (2t).
Yield: 0.301 g (70%). 1H NMR, CDCl3, 400 MHz, δ (ppm):
7.54-7.51 (m, 4H), 7.16 (s, 1H), 6.86-6.83 (m, 4H), 4.06 (s,
2H), 3.80 (s, 3H), 3.79 (s, 3H), 2.00 (s, 1H). 13C NMR, CDCl3,
100 MHz, δ (ppm): 159.8, 159.8, 135.5, 135.4, 134.2, 134.2,
132.6, 132.1, 115.1, 115.0, 67.2, 55.3, 55.3. MS (EI, 70 eV) m/z
(relative intensity): 251 (100), 242 (94), 225 (53), 213 (91), 198
(39), 188 (48), 107 (19). HRMS: calcd for C17H18O3Se2 429.9586,
found 429.9592.
(Z)-2,3-Bis(4-chlorophenylselanyl)prop-2-en-1-ol (2u).
Yield: 0.285 g (65%). 1H NMR, CDCl3, 400 MHz, δ (ppm):
7.51-7.45 (m, 4H), 7.34 (s, 1H), 7.30-7.25 (m, 4H), 4.15 (d, J
) 5.41 Hz, 2H), 1.83 (t, J ) 6.28 Hz, 1H). 13C NMR, CDCl3,
100 MHz, δ (ppm): 134.5, 134.3, 133.9, 133.6, 133.4, 132.3,
129.5, 129.5, 128.2, 126.7, 67.5. MS (EI, 70 eV) m/z (relative
intensity): 438 (10), 379 (17), 251 (62), 228 (52), 216 (100),
190 (77), 156 (58), 111 (38). HRMS: calcd for C15H12Cl2OSe2
437.8596, found 437.8601.
(Z)-1,2-Bis(phenylthio)pent-1-en-3-ol (2l). Yield: 0.242
1
g (80%). H NMR, CDCl3, 400 MHz, δ (ppm): 7.43-7.16 (m,
10H), 7.11 (s, 1H), 4.12 (q, J ) 6.43 Hz, 1H), 1.93 (s, 1H), 1.80-
1.58 (m, 2H), 0.91 (t, J ) 7.45 Hz, 3H). 13C NMR, CDCl3, 100
MHz, δ (ppm): 136.2, 134.8, 134.1, 132.0, 130.2, 129.0, 128.9,
128.6, 127.2, 126.2, 76.4, 29.0, 9.7. MS (EI, 70 eV) m/z (rela-
tive intensity): 284 (100), 269 (29), 175 (46), 167 (27),
143 (20), 77 (3). HRMS: calcd for C17H18OS2 302.0799, found
302.0807.
(Z)-2-Methyl-3,4-bis(methylthio)but-3-en-2-ol (2m).
Yield: 0.160 g (90%). 1H NMR, CDCl3, 400 MHz, δ (ppm): 6.70
(s, 1H), 2.36 (s, 3H), 2.29 (s, 3H), 2.27 (s, 1H), 1.43 (s, 6H). 13
C
NMR, CDCl3, 100 MHz, δ (ppm): 137.2, 135.1, 74.6, 28.8, 16.9,
16.5. MS (EI, 70 eV) m/z (relative intensity): 130 (80), 82 (100),
71 (23), 67 (55), 59 (21). HRMS: calcd for C7H14OS2 178.0486,
found 178.0492.
(Z)-1,2-Bis(phenylselanyl)pent-1-en-3-ol (2y). Yield: 0.330
1
g (83%). H NMR, CDCl3, 400 MHz, δ (ppm): 7.57-7.53 (m,
4H), 7.46 (s, 1H), 7.30-7.24 (m, 6H), 4.07 (q, J ) 5.99 Hz, 1H),
1.89 (d, J ) 5.55 Hz, 1H), 1.76-1.56 (m, 2H), 0.89 (t, J ) 7.45
Hz, 3H). 13C NMR, CDCl3, 100 MHz, δ (ppm): 135.9, 135.2,
133.2, 131.4, 130.5, 129.6, 129.3, 127.8, 127.1, 78.5, 29.4, 9.9.
MS (EI, 70 eV) m/z (relative intensity): 397 (1), 380 (27), 223
(60), 157 (33), 142 (100), 128 (32), 77 (31). HRMS: calcd for
C17H18OSe2 397.9688, found 397.9693.
(Z)-2-Methyl-3,4-bis(phenylthio)but-3-en-2-ol
(2n).
Yield: 0.235 g (78%). 1H NMR, CDCl3, 400 MHz, δ (ppm):
7.42-7.24 (m, 10H), 7.17-7.13 (m, 1H), 2.18 (s, 1H), 1.46 (s,
6H). 13C NMR, CDCl3, 100 MHz, δ (ppm): 137.7, 135.0, 134.95,
134.9, 130.5, 129.1, 128.9, 127.4, 127.0, 125.6, 75.0, 29.3. MS
(EI, 70 eV) m/z (relative intensity): 284 (100), 207 (18), 176
(99), 143 (62), 130 (14), 66 (8). HRMS: calcd for C17H18OS2
302.0799, found 302.0808.
(Z)-2-Methyl-3,4-bis(phenylselanyl)but-3-en-2-ol (2z).
Yield: 0.298 g (75%). 1H NMR, CDCl3, 400 MHz, δ (ppm): 7.61
(s, 1H), 7.56-7.49 (m, 4H), 7.30-7.19 (m, 6H), 2.13 (s, 1H),
1.45 (s, 6H). 13C NMR, CDCl3, 100 MHz, δ (ppm): 139.1, 136.8,
133.3, 130.7, 130.4, 130.0, 129.3, 129.3, 127.8, 126.6, 75.9, 29.4.
MS (EI, 70 eV) m/z (relative intensity): 380 (46), 314 (14), 222
(41), 157 (31), 142 (100), 128 (23), 77 (13). HRMS: calcd for
C17H18OSe2 397.9688, found 397.9695.
(Z)-1-(1,2-Bis(methylthio)vinyl)cyclohexanol
(2o).
Yield: 0.185 g (85%). 1H NMR, CDCl3, 400 MHz, δ (ppm): 6.70
(s, 1H), 2.35 (s, 3H), 2.28 (s, 3H), 1.97 (s, 1H), 1.79-1.56 (m,
10H). 13C NMR, CDCl3, 100 MHz, δ (ppm): 138.1, 135.9, 75.5,
36.2, 25.4, 21.9, 17.3, 16.8. MS (EI, 70 eV) m/z (relative
intensity): 200 (63), 185 (100), 137 (25), 110 (10). HRMS: calcd
for C10H18OS2 218.0799, found 218.0805.
General Procedure for the Preparation of the Tris-
chalcogenide Alkenes. n-Butyllithium (0.7 mL of a 1.567
M solution in hexane, 1.1 mmol) was added, under argon, to a
solution of alkyne (1 mmol) in THF (2 mL) previously cooled
at 0 °C. The resulting solution was stirred for 30 min at room
temperature. After this time, the mixture was cooled at 0 °C
and the disulfide or diselenide (3 mmol) in THF (1 mL) was
added. The mixture was then heated at reflux for 12 h, cooled
at room temperature, diluted with ethyl acetate (20 mL), and
washed with brine (2 × 20 mL). The organic phase was
separated, dried over MgSO4, and concentrated under vacuum.
The residue was purified by flash chromatography and eluted
with hexane/ethyl acetate (90:20) or hexane. 1-(1,2,2-Tris-
(Z)-1-(1,2-Bis(phenylthio)vinyl)cyclohexanol
(2p).
Yield: 0.239 g (70%). 1H NMR, CDCl3, 400 MHz, δ (ppm):
7.40-7.24 (m, 10H), 7.15-7.11 (m, 1H), 1.92 (s, 1H), 1.82-
1.53 (m, 10H). 13C NMR, CDCl3, 100 MHz, δ (ppm): 138.0,
135.4, 135.1, 135.0, 130.3, 129.0, 128.7, 127.2, 126.7, 125.3,
75.7, 36.1, 25.1, 21.7. MS (EI, 70 eV) m/z (relative intensity):
342 (1), 324 (100), 247 (14), 215 (59), 182 (47), 147 (33), 109
(22), 77 (43). HRMS: calcd for C20H22OS2 342.1112, found
342.1118.
(Z)-3-Methyl-1,2-bis(phenylthio)pent-1-en-3-ol (2q).
Yield: 0.243 g (77%). 1H NMR, CDCl3, 400 MHz, δ (ppm):
7.41-7.25 (m, 10H), 7.15 (t, J ) 7.75 Hz, 1H), 2.02 (s, 1H),
1
(methylthio)vinyl)benzene (3a). Yield: 0.206 g (85%). H
1.84-1.66 (m, 2H), 1.41 (s, 3H), 0.88 (t, J ) 7.45 Hz, 3H). 13
C
NMR, CDCl3, 400 MHz, δ (ppm): 7.40-7.18 (m, 5H), 2.44 (s,
3H), 2.14 (s, 3H), 1.83 (s, 3H). 13C NMR, CDCl3, 100 MHz, δ
(ppm): 145.2, 138.2, 129.2, 128.1, 127.7, 127.3, 18.3, 17.0, 16.7.
MS (EI, 70 eV) m/z (relative intensity): 242 (100), 194 (7), 179
(17), 160 (11), 147 (7). HRMS: calcd for C11H14S3 242.0258,
found 242.0263.
NMR, CDCl3, 100 MHz, δ (ppm): 138.1, 135.0, 134.8, 134.0,
130.3, 129.0, 128.8, 127.2, 125.6, 77.5, 33.8, 26.6, 8.1. MS (EI,
70 eV) m/z (relative intensity): 298 (100), 222 (34), 190 (42),
162 (39), 148 (18), 77 (7). HRMS: calcd for C18H20OS2 316.0955,
found 316.0960.
(Z)-2,3-Bis(phenylselanyl)prop-2-en-1-ol (2r). Yield: 0.333
1
1-(1-Phenyl-2,2-bis(phenylselanyl)vinylselanyl)-
benzene (3b). Yield: 0.435 g (76%). 1H NMR, CDCl3, 400
MHz, δ (ppm): 7.44-6.97 (m, 20H). 13C NMR, CDCl3, 100
MHz, δ (ppm): 148.9, 140.5, 135.8, 133.4, 132.7, 132.3, 131.8,
130.6, 129.0, 128.8, 128.5, 128.4, 127.8, 127.4, 127.35, 127.3,
127.2, 117.3. MS (EI, 70 eV) m/z (relative intensity): 334 (26),
312 (13), 258 (89), 179 (100), 153 (15). HRMS: calcd for C26H20-
Se3 571.9061, found 571.9068.
g (90%). H NMR, CDCl3, 400 MHz, δ (ppm): 7.59-7.53 (m,
4H), 7.39 (s, 1H), 7.32-7.27 (m, 6H), 4.14 (s, 2H), 1.86 (s, 1H).
13C NMR, CDCl3, 100 MHz, δ (ppm): 133.4, 133.2, 132.4, 132.2,
130.3, 129.4, 129.3, 128.6, 127.8, 127.5, 67.6. MS (EI, 70 eV)
m/z (relative intensity): 369 (86), 312 (41), 212 (67), 195 (100),
181 (72), 155 (68), 78 (20). HRMS: calcd for C15H14OSe2
369.9375, found 369.9382.
(Z)-2,3-Bis(mesitylselanyl)prop-2-en-1-ol (2s). Yield:
1
3-Ethoxy-1,1,2-tris(methylthio)prop-1-ene (3e). Yield:
0.363 g (80%). H NMR, CDCl3, 400 MHz, δ (ppm): 6.95 (s,
1
0.199 g (89%). H NMR, CDCl3, 400 MHz, δ (ppm): 4.59 (s,
2H), 6.94 (s, 2H), 6.71 (s, 1H), 3.78 (d, J ) 5.70 Hz, 2H), 2.53
(s, 6H), 2.50 (s, 6H), 2.28 (s, 3H), 2.27 (s, 3H), 1.40 (t, J ) 5.70
Hz, 1H). 13C NMR, CDCl3, 100 MHz, δ (ppm): 143.3, 142.8,
138.8, 138.7, 132.7, 128.8, 128.7, 128.2, 127.0, 125.5, 66.8, 24.5,
24.3, 20.9, 20.9. MS (EI, 70 eV) m/z (relative intensity): 453
(5), 237 (32), 225 (100), 198 (29), 119 (46). HRMS: calcd for
C21H26OSe2 454.0314, found 454.0320.
2H), 3.51 (q, J ) 7.02 Hz, 2H), 2.44 (s, 3H), 2.37 (s, 3H), 2.27
(s, 3H), 1.23 (t, J ) 7.02 Hz, 3H). 13C NMR, CDCl3, 100 MHz,
δ (ppm): 141.5, 130.2, 68.7, 64.8, 18.3, 16.7, 15.2, 15.1. MS
(EI, 70 eV) m/z (relative intensity): 224 (100), 179 (48), 161
(9), 128 (9). HRMS: calcd for C8H16OS3 224.0363, found
224.0369.
J. Org. Chem, Vol. 70, No. 13, 2005 5267

Moro et al.
1-(3-Ethoxy-1,1-bis(phenylselanyl)prop-1-en-2-yl-
selanyl)benzene (3f). Yield: 0.482 g (87%). 1H NMR, CDCl3,
400 MHz, δ (ppm): 7.33-7.15 (m, 15H), 4.26 (s, 2H), 3.21 (q,
J ) 7.02 Hz, 2H), 1.07 (t, J ) 7.02 Hz, 3H). 13C NMR, CDCl3,
100 MHz, δ (ppm): 144.1, 135.4, 133.9, 132.4, 132.3, 131.4,
130.0, 128.9, 128.7, 128.6, 128.3, 127.6, 127.1, 124.0, 72.6, 65.2,
15.0. MS (EI, 70 eV) m/z (relative intensity): 312 (29), 270
(58), 234 (34), 195 (81), 155 (35), 114 (100). HRMS: calcd for
C23H22OSe3 553.9166, found 553.9171.
2.35 (s, 3H), 2.25 (s, 3H), 1.03 (t, J ) 7.16 Hz, 6H). 13C NMR,
CDCl3, 100 MHz, δ (ppm): 144.8, 127.4, 54.8, 45.7, 18.2, 16.8,
15.5, 11.4. MS (EI, 70 eV) m/z (relative intensity): 251 (100),
204 (27), 179 (18), 156 (7), 86 (39). HRMS: calcd for C10H21-
NS3 251.0836, found 251.0841.
N,N-Diethyl-2,3,3-tris(phenylselanyl)prop-2-en-1-
amine (3l). Yield: 0.331 g (57%). 1H NMR, CDCl3, 400 MHz,
δ (ppm): 7.31-7.15 (m, 15H), 3.45 (s, 2H), 2.44 (q, J ) 7.02
Hz, 4H), 0.88 (t, J ) 7.02 Hz, 6H). 13C NMR, CDCl3, 100 MHz,
δ(ppm): 135.0, 133.5, 133.3, 132.9, 132.3, 131.2, 128.9, 128.6,
128.6, 128.4, 127.8, 127.3, 127.2, 127.1, 59.5, 45.2, 11.1. MS
(EI, 70 eV) m/z (relative intensity): 263 (17), 177 (190), 148
(100), 115 (33), 85 (43). HRMS: calcd for C25H27NSe3 580.9639,
found 580.9645.
4-(2,3,3-Tris(methylthio)allyl)morpholine (3m). Yield:
0.204 g (77%). 1H NMR, CDCl3, 400 MHz, δ (ppm): 3.69 (t,
J ) 4.53 Hz, 4H), 3.63 (s, 2H), 2.50 (s, 3H), 2.48 (t, J ) 4.53
Hz, 4H), 2.35 (s, 3H), 2.24 (s, 3H). 13C NMR, CDCl3, 100 MHz,
δ (ppm): 142.2, 128.0, 67.1, 58.9, 52.8, 17.9, 16.7, 15.2. MS
(EI, 70 eV) m/z (relative intensity): 265 (100), 252 (34), 218
(85), 170 (58) 100 (67). HRMS: calcd for C10H19NOS3 265.0629,
found 265.0634.
3-(2,3,3-Tris(methylthio)allyloxy)-1,1,2-tris(methyl-
thio)prop-1-ene (3o). Yield: 0.198 g (53%). 1H NMR, CDCl3,
400 MHz, δ (ppm): 4.61 (s, 2H), 2.46 (s, 3H), 2.38 (s, 3H), 2.29
(s, 3H). 13C NMR, CDCl3, 100 MHz, δ (ppm): 140.7, 131.8, 68.4,
18.4, 16.8, 15.4. MS (EI, 70 eV) m/z (relative intensity): 373
(8), 327 (9), 195 (22), 177 (62), 160 (100). HRMS: calcd for
C12H22OS6 373.9995, found 374.0002.
1-(1,1-Bis(4-chlorophenylselanyl)-3-ethoxyprop-1-en-
2-ylselanyl)-4-chlorobenzene (3g). Yield: 0.439 g (67%). 1H
NMR, CDCl3, 400 MHz, δ (ppm): 7.61-7.12 (m, 12H), 4.23 (s,
2H), 3.24 (q, J ) 7.02 Hz, 2H), 1.11 (t, J ) 7.02 Hz, 3H). 13C
NMR, CDCl3, 100 MHz, δ (ppm): 144.1, 136.7, 135.2, 135.0,
134.4, 134.3, 133.8, 133.7, 130.0, 129.2, 129.0, 128.9, 127.9,
123.8, 72.6, 65.5, 15.1. MS (EI, 70 eV) m/z (relative intensity):
656 (4), 460 (22), 381 (19), 273 (33), 228 (100), 188 (81), 154
(65). HRMS: calcd for C23H19Cl3OSe3 655.7997, found 655.8004.
1-(3-Ethoxy-1,2-bis(4-methoxyphenylselanyl)prop-1-
enylselanyl)-4-methoxybenzene (3h). Yield: 0.322 g (50%).
1H NMR, CDCl3, 400 MHz, δ (ppm): 7.63-6.72 (m, 12H), 4.21
(s, 2H), 3.81 (s, 3H), 3.79 (s, 3H), 3.78 (s, 3H), 3.21 (q, J )
7.02 Hz, 2H), 1.10 (t, J ) 7.02 Hz, 3H). 13C NMR, CDCl3, 100
MHz, δ (ppm): 160.1, 159.6, 159.3, 143.3, 137.8, 135.9, 134.7,
123.9, 122.6, 122.0, 120.3, 114.5, 114.4, 114.3, 72.0, 65.1, 55.2,
55.2, 55.2, 15.1. MS (EI, 70 eV) m/z (relative intensity): 642
(3), 371 (53), 293 (58), 267 (27), 187 (100), 145 (65). HRMS:
calcd for C26H28O4Se3 643.9483, found 643.9490.
3-Ethoxy-1,1,2-tris(methylthio)pent-1-ene (3i). Yield:
1
0.184 g (73%). H NMR, CDCl3, 400 MHz, δ (ppm): 4.99 (t, J
1-(3-(2,3,3-Tris(phenylselanyl)allyloxy)-1,1-bis(phenyl-
) 7.16 Hz, 1H), 3.54-3.28 (m, 2H), 2.41 (s, 3H), 2.40 (s, 3H),
2.28 (s, 3H), 1.86-1.59 (m, 2H), 1.19 (t, J ) 7.02 Hz, 3H), 0.89
(t, J ) 7.16 Hz, 3H). 13C NMR, CDCl3, 100 MHz, δ (ppm):
143.6, 138.6, 82.7, 64.0, 27.5, 18.4, 17.8, 17.1, 15.2, 10.2. MS
(EI, 70 eV) m/z (relative intensity): 251 (100), 222 (24), 206
(83), 195 (9). HRMS: calcd for C10H20OS3 252.0676, found
252.0682.
selanyl)prop-1-en-2-ylselanyl)benzene (3p). Yield: 0.465
1
g (45%). H NMR, CDCl3, 400 MHz, δ (ppm): 7.30-7.11 (m,
15H), 4.18 (s, 2H). 13C NMR, CDCl3, 100 MHz, δ (ppm): 142.4,
134.8, 134.2, 132.5, 132.4, 131.6, 130.4, 129.1, 128.7, 128.6,
128.1, 127.6, 127.1, 127.1, 72.6. HRMS: calcd for C42H34OSe6
1033.7601, found 1033.7609.
1-(3-Ethoxy-1,1-bis(phenylselanyl)pent-1-en-2-yl-
selanyl)benzene (3j). Yield: 0.413 g (71%). 1H NMR, CDCl3,
400 MHz, δ (ppm): 7.31-7.10 (m, 15H), 4.67 (m, 1H), 3.51-
3.26 (m, 2H), 1.88-1.44 (m, 2H), 1.10 (t, J ) 6.87 Hz, 3H),
0.88 (t, J ) 7.31 Hz, 3H). 13C NMR, CDCl3, 100 MHz, δ (ppm):
144.6, 135.5, 132.7, 132.3, 131.9, 131.7, 131.6, 129.2, 129.0,
128.7, 128.3, 127.9, 127.1, 127.0, 85.1, 64.5, 27.8, 15.2, 10.3.
MS (EI, 70 eV) m/z (relative intensity): 578 (18), 426 (44), 334
(76), 312 (100), 256 (60), 176 (64), 154 (33). HRMS: calcd for
C25H26OSe3 581.9479, found 581.9485.
Acknowledgment. We thank the following agencies
for support: FAPERGS, CNPq, CAPES, and UFSM.
CNPq is also acknowledged for an MS fellowship
(A.V.M.). G.Z. is the recipient of a CNPq fellowship.
Supporting Information Available: Experimental pro-
cedures, additional experimental details for the preparation
1
of compounds 2a-z and 3a-p, and H and 13C NMR spectra
for all reaction products. This material is available free of
charge via the Internet at http://pubs.acs.org.
N,N-Diethyl-2,3,3-tris(methylthio)prop-2-en-1-amine
(3k). Yield: 0.161 g (64%). 1H NMR, CDCl3, 400 MHz, δ
(ppm): 3.68 (s, 2H), 2.54 (q, J ) 7.16 Hz, 4H), 2.50 (s, 3H),
JO050448O
5268 J. Org. Chem., Vol. 70, No. 13, 2005