Reactions of sodium selenide with ethynyl and bromoethynyl ketones: Stereo- and regioselective synthesis of functionalized divinyl selenides and 1,3-diselenetanes

Article abstract of DOI:10.1016/j.jorganchem.2009.07.023

A method for the preparation of 2,4-dimethylene-1,3-diselenetanes based on the novel reaction of sodium selenide with bromoethynyl ketones has been developed. New functionalized divinyl selenides have been obtained by regio- and stereoselective addition o

Full text of DOI:10.1016/j.jorganchem.2009.07.023

Journal of Organometallic Chemistry 694 (2009) 3679–3682
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Note
Reactions of sodium selenide with ethynyl and bromoethynyl ketones: Stereo- and
regioselective synthesis of functionalized divinyl selenides and 1,3-diselenetanes
*
Vladimir A. Potapov , Valentina N. Elokhina, Lyudmila I. Larina, Tatiana I. Yaroshenko,
*
Anna A. Tatarinova, Svetlana V. Amosova
A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Division of the Russian Academy of Sciences, 1 Favorsky Str., 664033 Irkutsk, Russia
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 13 May 2009
Received in revised form 9 July 2009
Accepted 10 July 2009
Available online 15 July 2009
A method for the preparation of 2,4-dimethylene-1,3-diselenetanes based on the novel reaction of
sodium selenide with bromoethynyl ketones has been developed. New functionalized divinyl selenides
have been obtained by regio- and stereoselective addition of sodium selenide to ethynyl ketones.
Ó 2009 Elsevier B.V. All rights reserved.
Keywords:
Bromoethynyl ketones
1,3-Diselenetanes
Divinyl selenides
Ethynyl ketones
Sodium selenide
1. Introduction
2. Results and discussion
Vinylic selenides are powerful tools in synthetic organic chem-
istry [1–5]. The data on diselenetanes synthesis are scarce in the
literature. Only a few representatives of the 1,3-diselenetanes are
known [6–10]. 2,4-Bis(methylene)-, bis(methylmethylene)- and
bis(tert-butylmethylene)-1,3-diselenetanes have been synthesized
from the corresponding selenoketenes generated from 1,2,3-selen-
adiazoles [6]. Hexafluoropropene reacted with selenium in DMF in
the presence of CsF at 45–55 °C to give tetrakis(trifluoromethyl)-
1,3-diselenetane in 50% yield [7]. The reaction of tert-butyl
(p-methoxyphenyl)methylenetriphenylphosphorane tetrafluorobo-
rate with elemental selenium afforded substituted 2,4-bis(tert-
butyl)-2,4-bis(p-methoxyphenyl)-1,3-diselenetane in 24% yield
[8]. The perfluorinated 1,3-diselenetanes have been prepared from
selenocarbonyl compounds [9].
The synthesis of vinylic selenides and their reactions is a field of
our continuous interest [11–22]. Earlier, we have developed effi-
cient methods for the preparation of divinyl selenide and alkyl vi-
nyl selenides [15–22]. Our thorough research of the reactions of
various selenium reagents with acetylenes [15–28] led us to study
the reactions of sodium selenide with ethynyl ketones 1a–d and
bromoethynyl ketones 2a,b.
We have found that the reaction of sodium selenide with ethy-
nyl ketones 1a–d proceeds as regio- and stereoselective anti-addi-
tion to afford Z,Z-bis(acylvinyl) selenides 3a–d in 47–76% yields
(Scheme 1). Sodium selenide was prepared from elemental sele-
nium and sodium borohydride in ethanol and used in situ for fur-
ther reactions.
In the 1H NMR spectra of selenide 3a, signals of vinylic protons
of the Se–CH@CH–CO group were observed as doublets at d 7.79
Previously, we have studied the reaction of selenourea with
benzoylbromoacetylene and 2-thienoylbromoacetylene. The reac-
tion proceeds in the presence of triethylamine affording E-2,
4-bis(benzoylmethylene)-1,3-diselenetane and E-2,4-bis(2-thi-
enoylmethylene)-1,3-diselenetane [10].
3
and 8.55 ppm with JHH = 9.5 Hz, that indicated Z-stereochemistry
of the product. The methods of homonuclear (NOESY 1H–1H) and
heteronuclear 2D NMR (Heteronuclear Single Quantum Correla-
tion, Heteronuclear Multiple Bond Correlation) were used for the
assignment. The cross peaks induced by dipole–dipole interaction
between the vinylic proton at d 7.79 ppm and the proton H-3 of
the thiophene ring appeared in the 2D NOESY NMR spectra of
selenide 3a (Scheme 2). Therefore, the signal at d 7.79 ppm was
attributed to the proton of the @CH–CO group and a low-field
signal at d 8.55 ppm corresponded to the proton of the SeCH group.
* Corresponding authors.
E-mail addresses: v_a_potapov@irioch.irk.ru (V.A. Potapov), amosova@irioch.
irk.ru (S.V. Amosova).
0022-328X/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2009.07.023

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V.A. Potapov et al. / Journal of Organometallic Chemistry 694 (2009) 3679–3682
effect of benzoyl or 2-thienoyl groups is significantly higher than
NaBH4
EtOH
Se
Na2Se
that of phenyl group and carbanion 5 is energetically preferable
in comparison with intermediate 6 (Scheme 3).
The 77Se spectra of selenides 3c and 3d were characterized by
the coupling constants 3JSeH = 6.3 Hz, that pointed to trans-position
of the vinylic proton and the selenium atom and indicated
Z-stereochemistry.
R
R
O
EtOH
R'
Se
3a-d
R'
Na2Se
2 R
O
O
R'
1a-d
Unexpectedly, the reaction of sodium selenide with bromoethy-
nyl ketones 2a,b gave E-2,4-bis(benzoylmethylene)- and E-2,4-
bis(2-thienoylmethylene)-1,3-diselenetanes 4a,b in 79% and 77%
yields, respectively. A reaction pathway was suggested to involve
the formation of selenoketenes, which underwent [2+2] cycloaddi-
tion to form diselenetanes 4a,b (Scheme 4). It is noteworthy that
dimerisation of thiocarbonyl compounds to 1,3-dithietanes is a
known process [29].
R = H, R' = 2-Th (1a, 3a); R = H, R' = Ph (1b, 3b);
R = R' = Ph (1c, 3c); R = Ph, R' = 2-Th (1d, 3d)
Scheme 1.
Usually protons of the SeCH group in vinylic selenides revealed sig-
nals at 6.0–6.9 ppm [2,3,22]. A down-field shift of the vinylic pro-
ton was obviously due to electron withdrawing effect of the
carbonyl group leading to appearance of partly positive charge
on the b-carbon atom of the CH@CH–CO group. This can be demon-
strated with the help of mesomeric structures (Scheme 2). Analo-
gously, in the NOESY spectra of selenide 3b, the proton of the
@CH–CO group showed cross peaks with the ortho-proton of the
phenyl ring (Scheme 2). Based on this observation we assumed
that favorable conformations of the fragments Th–CO–CH@CH–Se
and Ph–CO–CH@CH–Se in compounds 3a and 3b were close to
plane.
R
O
R
O
Se
Se
2 Na2Se
2 Br
2 NaBr
O
R
2a,b
4a,b
O
O
−
Se2
Br
Se
Br
R
R
The 77Se spectra of selenides 3a and 3b were characterized by
2
3
the coupling constants JSeH (8.1 and 8.4 Hz) and JSeH (5.5 and
5.3 Hz, trans-position of the vinylic proton and the selenium atom).
In the NOESY spectra of selenide 3c, the vinylic proton at d 7.59
showed cross peaks with the ortho-proton of the phenyl ring of the
benzoyl group (Scheme 2). This indicated the Ph–CO–CH@ struc-
ture and therefore addition of selenide anion occured to the
b-carbon of ethynyl ketone 1c. Similar trends were observed in
the case of selenide 3d. The NOESY spectra of selenide 3d were
characterized by cross peaks of the vinylic proton at d 7.36 with
the proton H-3 of the thiophene ring (Scheme 2). This revealed
the Th–CO–CH@ structure and addition of selenide anion to the
b-carbon of ethynyl ketone 1d. Thus, the addition of selenide anion
to the b-carbon of ethynyl ketones 1c,d was favorable in compari-
R
R
O
R
EtOH
O
O
Se
.
Se
.
Se
R
R
O
O
Se
Se
.
Se
.
O
Se
R
O
4a,b
R
R = Ph (2a, 4a); R = 2-Th (2b, 4b)
Scheme 4.
son with the addition to the
a-carbon. The electron withdrawing
NOE
NOE
H3
R
R
R
R
H
H
H
H
H
H H
H4
H5
H
Se
Se
S
S
H
O
O
O
O
3b,c
3a,d
O
Se
O
3a,b
O
Se
O
O
Se
O
R'
R'
R'
R'
R'
R'
R = H, R' = 2-Th (3a); R = H, R' = Ph (3b); R = R' = Ph (3c); R = Ph, R' = 2-Th (3d)
Scheme 2.
O
Ph
Se
R'
Ph
Se
O
R'
.
Ph
Na2Se
R'
O
R'
Se
Ph
O
5
6
R' = Ph (3c), R' = 2-Th (3d)
Scheme 3.

V.A. Potapov et al. / Journal of Organometallic Chemistry 694 (2009) 3679–3682
3681
The structural assignment of compounds 4a,b was made by 1H,
13C and 77Se NMR spectroscopy and GC–MS. In the mass spectra of
compounds 4a,b, the molecular ions (420 for 4a and 432 for 4b)
were observed. The choice between the structures of the Z- and
E-isomers of 1,3-diselenetanes 4a,b was made based on the 77Se
spectra, which contained only one signal. The selenium atoms
are chemically equivalent in the E-isomers, which give one signal
in the 77Se spectra, whereas the Z-isomers having two different
selenium atoms should show two signals in the 77Se spectra. The
dioxane). IR (KBr): 1575 (C=C), 1640 (C=O) cmÀ1
d6): d 7.57 dd (4H, Ph, meta), 7.66 t (2H, Ph, para), 7.92 d (2H, CO–
CH, 3J = 9.5 Hz), 8.09 d (4H, Ph, ortho), 8.63 d (2H, SeCH, 3J = 9.5 Hz).
13C NMR (DMSO-d6): d 122.31 (CH–CO), 128.33 (Ph, ortho), 129.04
.
1H NMR (DMSO-
(Ph, meta), 133.35 (Ph, para), 137.04 (Ph, ipso), 154.20 (SeCH=),
189.59 (C@O). 77Se NMR (DMSO-d6): d 600 (2JSeH = 8.4, JSeH
=
3
5.3 Hz). GC–MS, m/z (rel. int.): 342 (39) [M]+, 286 (35), 262 (28),
211 (75), 157 (25), 105 (100), 77 (95). Anal. Calc. for C18H14O2Se:
C, 63.34; H, 4.10; Se, 23.16. Found: C, 63.25; H, 4.12; Se, 23.00.
3
coupling constants JSeH (10.5 Hz for 4a and 11.5 Hz for 4b) corre-
spond to cis-position of the selenium atom and the vinylic proton.
Spectral characteristics of diselenetanes 4a,b are in accordance
with those of known samples which we previously obtained from
bromoacetylene 2a,b and selenourea [10].
The method represents simple and efficient approach to 2,4-
dimethylene-1,3-diselenetanes. We expect that this method can
be also used for generation of selenoketenes, which would then
be used for further reactions, e.g., addition reactions on the double
bond of selenoketenes [6].
In conclusion, new functionalized divinyl selenides have been
synthesized by regio- and stereoselective addition of sodium
selenide to ethynyl ketones. A novel method for the preparation
of 2,4-dimethylene-1,3-diselenetanes based on the novel reaction
of sodium selenide with bromoethynyl ketones has been developed.
3.4. Z,Z-Bis(2-benzoyl-1-phenylvinyl) selenide (3c)
Selenide 3c was prepared analogously to 3a from elemental
selenium (0.25 g, 3.2 mmol), sodium borohydride (0.25 g,
6.5 mmol) and acetylene 1c (1.23 g, 6 mmol) to yield 1.06 g (72%)
of selenide 3c as a light-yellow solid, m.p. 171–173 °C. IR (KBr):
1585 (C@C), 1640 (C@O) cmÀ1 1H NMR (DMSO-d6): d 7.05 dd
.
(4H, Ph, meta), 7.19 t (2H, Ph, para), 7.59 dd (4H, PhCO, meta),
7.59 s (2H, CH–CO), 7.68 t (2H, PhCO, para), 8.11 d (4H, PhCO,
ortho), 8.67 d (4H, Ph, ortho). 13C NMR (DMSO-d6): d 126.67
(@CH–CO), 128.07 (meta, Ph), 128.14 (ortho, Ph), 128.64 (meta,
Ph), 128.64 (ortho, PhCO), 129.17 (meta, PhCO), 133.47 (para,
PhCO), 137.26 (PhCO, ipso), 141.36 (Ph, ipso), 158.32 (SeC),
189.20 (C@O). 77Se NMR (DMSO-d6): d 593 (3JSeH = 6.3 Hz). Anal.
Calc. for C30H22O2Se: C, 73.02; H, 4.46; Se, 16.32. Found: C,
73.15; H, 4.33; Se, 16.02.
3. Experimental
3.5. Bis[2-(2-thienoyl)-1-phenylvinyl] selenide (3d)
3.1. General
1H (400.1 MHz), 13C (100.6 MHz) and 77Se (76.3 MHz) NMR
spectra were recorded on a Bruker DPX-400 spectrometer in 5–
10% solution in DMSO-d6, referenced to TMS (1H and 13C NMR,
internal) and Me2Se (77Se NMR, external). GC–MS spectra were re-
corded on a Shimadzu QP5050A spectrometer at an electron en-
ergy of 70 eV.
Selenide 3d was prepared analogously to 3a from elemental
selenium (0.25 g, 3.2 mmol), sodium borohydride (0.25 g,
6.5 mmol) and acetylene 1d (1.35 g, 6.4 mmol) to yield 1.15 g
(76%) of selenide 3d as a light-yellow solid. M.p. 169–170 °C. IR
(KBr): 1580 (C@C), 1635 (C@O) cmÀ1 1H NMR (DMSO-d6): d 6.66
.
dd (2H, C4H3S, H4, 3J = 1.6, 3J = 3.6 Hz), 6.83 d (4H, Ph, ortho), 7.05
dd (4H, Ph, meta), 7.16 t (2H, Ph, para), 7.36 s (2H, CH–CO), 7.69
d (2H, C4H3S, H3, 3J = 3.6 Hz), 8.06 d (2H, C4H3S, H5, 3J = 1.6 Hz).
13C NMR (DMSO-d6): d 113.15 (C4H3S, C4), 119.27 (C4H3S, C3),
125.48 (@CH), 128.05 (Ph, ortho), 128.18 (Ph, meta), 128.70 (Ph,
para), 141.42 (SeC), 148.45 (C4H3S, C5), 152.92 (C4H3S, C2), 158.51
3.2. Z,Z-Bis[2-(2-thienoylvinyl] selenide (3a)
Sodium borohydride (0.25 g, 6.5 mmol) was added portion wise
to a mixture of elemental selenium (0.25 g, 3.2 mmol) and absolute
ethanol (20 ml) for 0.5 h at room temperature under argon atmo-
sphere. A solution of acetylene 1a (0.89 g, 6.5 mmol) in diethyl
ether (20 ml) was added to the reaction mixture and stirred for
2 h at room temperature under argon. Precipitation of a yellow so-
lid was observed. The reaction mixture was cooled to 0 °C for 1 h
and the precipitated yellow solid was filtered off, washed progres-
sively with water, ethanol and diethyl ether and dried in vacuo to
give 0.65 g (58% yield) of selenide 3a as a light-yellow solid. M.p.
197–198 °C (from methanol). IR (KBr): 1585 (C@C), 1660 (C@O)
(Ph, ipso), 175.75 (C@O). 77Se NMR (DMSO-d6):
d
599
(3JSeH = 6.3 Hz). GC–MS, m/z (rel. int.): 506 (11) [M]+, 290 (11),
277 (75), 264 (44), 238 (47), 214 (52), 126 (71), 111 (18), 105
(100), 83 (70), 77 (62).
3.6. E-2,4-bis(benzoylmethylene)-1,3-diselenetane (4a)
Sodium borohydride (0.25 g, 6.5 mmol) was added portion wise
to a mixture of elemental selenium (0.25 g, 3.2 mmol) and absolute
ethanol (20 ml), for 0.5 h at room temperature under argon atmo-
sphere. Bromoacetylene 2a (0.81 g, 4 mmol) was added to the reac-
tion mixture and stirred for 3 h at room temperature under argon.
Precipitation of a yellow solid was observed. The reaction mixture
was cooled to 0 °C for 1 h and the precipitated yellow solid was fil-
tered off, washed progressively with water, ethanol and diethyl
ether and dried in vacuo to give 0.53 g (79% yield) of diselenetane
4a as a light-yellow solid. M.p. 203–204 °C. Spectral characteristics
of diselenetane 4a correspond to those of known sample obtained
from bromoacetylene 2a and selenourea [10].
cmÀ1 1H NMR (DMSO-d6): d 7.28 dd (2H, 3J = 3.7, 3J = 4.7 Hz,
.
C4H3S, H4), 7.79 d (2H, CO–CH, 3J = 9.5 Hz), 8.06 (2H, 3J = 4.7 Hz,
C4H3S, H5), 8.16 d (2H, 3J = 3.7 Hz, C4H3S, H3), 8.55 d (2H, Se–CH,
3J = 9.5 Hz). 13C NMR (DMSO-d6): d 122.92 (C4H3S, C4), 129.74
(CO–CH, 1J 171.0) 133.75 (C4H3S, C3), 136.24 (C4H3S, C5), 145.12
1
(C4H3S, C2), 153.27 (SeCH@, JSeC = 175.0 Hz), 182.90 (C@O). 77Se
3
NMR (DMSO-d6): d 592 (2JSeH = 8.1, JSeH = 5.5 Hz). Anal. Calc. for
C14H10O2S2Se: C, 47.59; H, 2.53; S, 18.13; Se, 22.37. Found: C,
47.49; H, 2.83; S, 18.28; Se, 22.63%.
3.3. Z,Z-Bis(2-benzoylvinyl) selenide (3b)
3.7. E-2,4-bis(2-thienoylmethylene)-1,3-diselenetane (4b)
Selenide 3b was prepared analogously to 3a from elemental
selenium (0.25 g, 3.2 mmol), sodium borohydride (0.25 g,
6.5 mmol) and acetylene 1b (0.85 g, 6.5 mmol) to yield 0.51 g
(47%) of selenide 3b as a light-yellow solid. M.p. 203–204 °C (from
Diselenetane 4b was prepared analogously to 4a from elemen-
tal selenium (0.25 g, 3.2 mmol), sodium borohydride (0.25 g,
6.5 mmol) and bromoacetylene 2b (1.33 g, 6 mmol) to yield 0.5 g

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V.A. Potapov et al. / Journal of Organometallic Chemistry 694 (2009) 3679–3682
[13] V.A. Potapov, K.A. Volkova, M.V. Penzik, A.I. Albanov, S.V. Amosova, Russ. J.
Gen. Chem. 78 (2008) 1990.
[14] Y.Y. Rusakov, L.B. Krivdin, N.V. Istomina, V.A. Potapov, S.V. Amosova, Magn.
Reson. Chem. 46 (2008) 979.
(77%) as a light-yellow solid. M.p. 274–275 °C. Spectral character-
istics of diselenetane 4b correspond to those of known sample
obtained from bromoacetylene 2b and selenourea [10].
[15] V.A. Potapov, S.V. Amosova, Russ. J. Org. Chem. 39 (2003) 1373.
[16] B.A. Trofimov, S.V. Amosova, N.K. Gusarova, V.A. Potapov, A.A. Tatarinova,
Sulfur Lett. 1 (1983) 151.
Acknowledgement
[17] V.A. Potapov, S.V. Amosova, Phosphorus Sulfur Silicon Relat. Elem. 79 (1993)
277.
[18] V.A. Potapov, S.V. Amosova, A.R. Zhnikin, V.Yu. Shestakova, Sulfur Lett. 19
(1995) 55.
The work was carried out on the Program of the Russian Acad-
emy of Sciences (Grant No. 5.1.8).
[19] V.A. Potapov, S.V. Amosova, A.R. Zhnikin, V.Yu. Shestakova, B.V. Petrov, A.I.
Albanov, Sulfur Lett. 19 (1995) 107.
[20] S.V. Amosova, V.A. Potapov, N.K. Gusarova, B.A. Trofimov, Zh. Org. Khim. 25
(1989) 2283.
[21] V.A. Potapov, N.K. Gusarova, S.V. Amosova, A.S. Kashik, B.A. Trofimov, Zh. Org.
Khim. 22 (1986) 276.
[22] N.K. Gusarova, V.A. Potapov, S.V. Amosova, A.S. Kashik, B.A. Trofimov, Zh. Org.
Khim. 19 (1983) 2477.
References
[1] G. Perin, E.J. Lenardão, R.G. Jacob, R.B. Panatieri, Chem. Rev. 109 (2009) 1277.
[2] C.C. Silveira, F. Rinaldi, R.C. Guadagnin, A.L. Braga, Synthesis (2009) 469.
[3] C.C. Silveira, P.C.S. Santos, S.R. Mendes, A.L. Braga, J. Organomet. Chem. 693
(2008) 3787.
[4] J.P. Das, U.K. Roy, S. Roy, Organometallics 24 (2005) 6136.
[5] G. Perin, R.G. Jacob, F. de Azambua, G.V. Botteselle, G.M. Siqueira, R.A. Freitag,
E.J. Lenardão, Tetrahedron Lett. 46 (2005) 1679.
[6] A. Holm, C. Berg, C. Bjerre, B. Bak, H. Swanholt, J. Chem. Soc., Chem. Commun.
(1979) 99.
[7] A. Haas, C. Limberg, S.R. Sterlin, J. Fluorine Chem. 53 (1991) 71.
[8] K. Okuma, T. Kubota, Tetrahedron Lett. 42 (2001) 3881.
[9] A. Haas, M. Spehr, J. Fluorine Chem. 45 (1989) 35.
[10] S.V. Amosova, V.N. Elokhina, A.S. Nakhmanovich, L.I. Larina, A.V. Martynov, B.R.
Steele, V.A. Potapov, Tetrahedron Lett. 49 (2008) 974.
[11] S.V. Amosova, K.A. Volkova, M.V. Penzik, A.I. Albanov, V.A. Potapov, Russ. J.
Gen. Chem. 78 (2008) 503.
[12] V.A. Potapov, K.A. Volkova, M.V. Penzik, A.I. Albanov, S.V. Amosova, Russ. J. Org.
Chem. 44 (2008) 1556.
[23] A.V. Martynov, A.V. Ivanov, S.V. Amosova, V.A. Potapov, Russ. J. Org. Chem. 42
(2006) 1083.
[24] V.A. Potapov, S.V. Amosova, O.V. Belozerova, A.I. Albanov, O.G. Yarosh, M.G.
Voronkov, Chem. Heterocycl. Compd. 39 (2003) 549.
[25] S.V. Amosova, A.V. Martynov, N.A. Mahaeva, O.V. Belozerova, M.V. Penzik, A.I.
Albanov, M.G. Voronkov, J. Organomet. Chem. 692 (2007) 946.
[26] S.V. Amosova, V.A. Shagun, A.V. Martynov, N.A. Makhaeva, L.I. Larina, K.A.
Lysenko, M.G. Voronkov, J. Organomet. Chem. 692 (2007) 3307.
[27] V.A. Potapov, S.V. Amosova, O.V. Belozerova, A.I. Albanov, O.G. Yarosh, M.G.
Voronkov, Chem. Heterocycl. Compd. 39 (2003) 551.
[28] L.V. Klyba, S.V. Amosova, O.V. Belozerova, V.A. Potapov, E.P. Zhanchipova, O.G.
Yarosh, M.G. Voronkov, Russ. Chem. Bull. Int. Ed. (2005) 650.
[29] V. Pushkara Rao, Sulfur Rep. 12 (1992) 359.