V.A. Potapov et al. / Journal of Organometallic Chemistry 694 (2009) 3679–3682
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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