Synthesis of novel vinylic P-Se heterocycles from selenation of alkynes by [PhP(Se)(μ-Se)]2

Article abstract of DOI:10.1002/ejic.200601066

Eleven novel five-membered PSe₂C2 heterocycles have been synthesised from [PhP(Se)(μ-Se)]₂ (Woollins' reagent) and alkynes (one or two C=C triple bonds) by insertion of a Ph(Se)-PSe₂ fragment into alkyne triple bonds. An unusual diselenide formed by an intramolecular cycloaddition/rearrangement is also reported. All compounds have been characterised spectroscopically and four demonstrative X-ray crystal structures are reported. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.

Full text of DOI:10.1002/ejic.200601066

FULL PAPER
DOI: 10.1002/ejic.200601066
Synthesis of Novel Vinylic P–Se Heterocycles from Selenation of Alkynes by
[PhP(Se)(µ-Se)]2
Guoxiong Hua,[a] Yang Li,[a] Alexandra M. Z. Slawin,[a] and J. Derek Woollins*[a]
Keywords: Selenium / Heterocycles / Alkynes / Woollins’ reagent / Cycloaddition
Eleven novel five-membered PSe2C2 heterocycles have been
ment is also reported. All compounds have been character-
synthesised from [PhP(Se)(µ-Se)]2 (Woollins’ reagent) and al- ised spectroscopically and four demonstrative X-ray crystal
kynes (one or two CϵC triple bonds) by insertion of a Ph(Se)-
PSe2 fragment into alkyne triple bonds. An unusual diselen-
ide formed by an intramolecular cycloaddition/rearrange-
structures are reported.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2007)
Introduction
Results and Discussion
Reaction of WR with Alkynes Containing one CϵC Triple
Bond
Organoselenenium chemistry has attracted increasing at-
tention in recent years. The interest in selenium-containing
compound lies not only in their chemo-, regio-, and stereo-
selective reactions but also their useful biological ac-
tivity.[1–7] However, the synthesis of selenium-containing
organic heterocycles can be problematic involving use of
toxic selenium reagents which are often difficult to handle.
WR reacts with one molar equivalent of phenylacetylene
or diphenylacetylene in toluene at 130 °C over 12 h to give
brown, air-stable crystals of PhP(Se)Se2(PhC=CH) (2) or
PhP(Se)Se2(PhC=CPh) (3), respectively, in high yields
(91% and 94%, based on WR) after column chromato-
graphic purification (silica gel, toluene as eluent)
and recrystallisation from dichloromethane/n-hexane
(Scheme 1).
2,4-Bis(phenyl)-1,3-diselenadiphosphetane
2,4-diselenide
[{PhP(Se)(µ-Se)}2] [1, Woollins’ reagent (WR)], a selenium
analogue of the well-known Lawesson’s reagent, [{(p-
MeOC6H4)P(S)(µ-S)}2] has less unpleasant chemical prop-
erties than many systems and can be easily prepared and
safely handled.[8,9]
WR has been shown to act as an efficient selenium trans-
fer reagent for the synthesis of a range of selenoamides and
selenoaldehydes by, for example, simple O/Se exchange re-
actions or reaction with ArCN followed by hydrolysis.[10–13]
We have also reported the use of FcP(S)S2P(S)Fc (Fc =
ferrocenyl) and WR in the preparation of novel metal com-
plexes, C–P–S and C–P–Se heterocycles by reaction with a
variety of reactive organic substrates/functionalities includ-
ing CS2, C=O, C=C double bond and CϵN triple
bonds.[8,14–19]
To date, no general method for the synthesis of vinylic
selenium-containing heterocycles has been established. We
have focused our attention on the preparation of a series of
novel vinylic heterocycles by reaction of WR with alkynes
and here describe a series of new heterocycles. Four X-ray
crystal structures have been determined.
Scheme 1. Synthesis of 2 and 3.
Although 2 was described previously by us no crystal
structure has been published. The data obtained here from
microanalysis and spectroscopic analysis match the litera-
ture data from our previous study of 2[15] except that the
yield was much improved by lengthening the reaction time
and increasing the reaction scale. The 31P{1H} NMR spec-
trum of 3 consists of a sharp singlet at δ = 74.3 ppm, ac-
companied by a pattern of selenium satellites with 31P-77Se
couplings of 357 and 779 Hz, respectively, similar to that
observed in 2. The 77Se{1H} NMR spectrum shows three
distinct doublet signals at δ = 519.3 ppm [2JP,Se 7 Hz], δ =
373.4 ppm [1JP,Se 358 Hz] and δ = –28.6 ppm [1JP,Se 777 Hz]
assigned as C–Se, P–Se and P=Se, respectively. The 1H
[a] School of Chemistry, University of St Andrews,
Fife, KY16 9ST, UK
E-mail: jdw3@st-and.ac.uk
Eur. J. Inorg. Chem. 2007, 891–897
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
891

G. Hua, Y. Li, A. M. Z. Slawin, J. D. Woollins
FULL PAPER
NMR spectrum of 3 shows that only aryl protons are pres- Table 1. Selected bond lengths [Å] and angles [°] for 2, 3, and 13.
ent.
The molecular structures of 2 and 3 (Figure 1 and Fig-
2
3
13[a]
Se(1)–P(1)
P(1)–Se(2)
P(1)–C(1)
2.1137(11) 2.0965(18) 2.1015(9) [2.1011(9)]
2.2616(10) 2.2511(17) 2.2432(9) [2.2612(8)]
ure 2, Table 1 and Table 3) are composed of approximately
planar five-membered C2PSe2 rings generated by the ad-
1.814(3)
1.783(3)
2.3735(7)
1.901(3)
1.339(4)
1.814(7)
1.822(7)
2.3417(9)
1.927(6)
1.345(9)
1.809(3) [1.812(3)]
1.826(3) [1.822(3)]
2.3484(5) [2.3473(5)]
1.929(3) [1.921(3)]
1.334(4)
100.06(10) [99.71(9)]
109.53(3) [117.80(3)]
90.96(2) [87.62 (2)]
122.6(19) [120.9(2)]
94.11(9) [95.43(9)]
119.6(2) [118.8(2)]
dition of Ph(Se)PSe2 fragments from WR to the CϵC bond P(1)–C(8)
Se(2)–Se(3)
of alkynes. For 2, the mean deviation of the Se(1)–C(7)–
Se(3)–C(7)
P(1)–C(8)–Se(2) plane is 0.13 Å, while in 3 the value is
C(7)–C(8)
0.25 Å, the extra deviation from planarity in 3 is also evi-
C(8)–P(1)–Se(2) 101.02(12) 98.6(2)
dent in a contraction of the P(1)–Se(2)–Se(3) and C(8)–
P(1)–Se(2) internal angles on going from 2 to 3 [92.18(3)°
and 101.02(12)° for 2, 89.56(5)° and 98.6(2)° for 3] and both
effects probably reflect the steric influence of the phenyl
group in 3 compared to a hydrogen atom in 2. The majority
of the other geometric parameters in these two compounds
are similar, thus the exocyclic P(1)–Se(1) bond lengths in 2
and 3 [2.1137(11) and 2.0965(18) Å, respectively] are in
good agreement with each other and consistent with the
related selenides containing PV=Se bonds [2.08–
2.12 Å].[9,15–18] The P(1)–Se(2) distances [2.2616(10) Å for 2
and 2.2511(17) Å for 3] are in the range for reported values
of heterocycles containing PV–Se single bonds.[8,9,15–18,20]
The C(7)–C(8) bond lengths in 2 and 3 are not significantly
different [1.339(4) and 1.345(9) Å, respectively], however,
the P(1)–C(8) bond length in 2 is shorter than that in 3
[1.783(3) vs. 1.822(7) Å] which may reflect the different elec-
tronic effect of a hydrogen atom compared to a phenyl
group. Finally, we note that the structure of 3 is chiral in the
solid state, i.e. the crystal examined was a single enantio-
mer.
Se(1)–P(1)–Se(2) 115.24(4)
P(1)–Se(2)–Se(3) 92.18(3)
Se(3)–C(7)–C(8) 121.0(3)
Se(2)–Se(3)–C(7) 96.41(10)
C(7)–C(8)–P(1) 124.8(3)
116.66(8)
89.56(5)
122.5(5)
94.3(2)
116.9(5)
[a] Dimensions for second independent molecule in square paren-
theses.
Reaction of WR with Alkynes Containing two CϵC Triple
Bonds
The reaction between WR and bis(phenylethynyl)ben-
zene or 9,10-bis(phenylethynyl)anthracene in refluxing tolu-
ene over 12 h gave two types of products, one involving cy-
cloaddition at one CϵC triple bond (4, 6, 8 and 10) and
the other involving cycloaddition at both CϵC triple bonds
(5, 7, 9 and 11) (Scheme 2). In 4–11 the phosphorus atoms
are potentially chiral but because there is no particular ste-
reocontrol in the reaction we would expect to see racemic
mixtures. Thus, 5, 7, 9 and 11 are diastereotopic with (R,R),
(R,S), (S,R) and (S,S) isomers being possible. In the
31P{1H} NMR of 5 we observed two phosphorus signals
with similar selenium satellites at δP = 73.3 and 73.0 ppm
(intensity ratio 9:1) [JP,Se = 357/774 and 360/770 Hz, respec-
tively] though we cannot assign them specifically to (R,R),
(S,S) and (R,S), (S,R). Further purification of 5, 7, 9, and
11 by recrystallisation from CH2Cl2/petroleum ether gave a
single signal arising from one pair of enantiomers which are
indistinguishable by NMR, [5a (11% yield), 7a (18% yield),
9a (15% yield) and 11a (17% yield)].
Figure 1. Molecular structure of 2 (C–H bonds omitted for clarity).
Figure 2. Molecular structure of 3 (C–H bonds omitted for clarity).
892
Scheme 2. Synthesis of 4–11.
www.eurjic.org
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2007, 891–897

Vinylic P–Se Heterocycles
FULL PAPER
The reaction between WR and 1,8-bis(phenylethynyl)- that in each compound there is one or more identical
naphthalene gave the expected compound 13 and a surpris- PhP(Se)–Se–Se fragment present and supporting the pres-
ing diselenide 12, which arises from an intramolecular cy- ence of both P–Se single and double bonds.[18]
cloaddition, but no product with cycloaddition at two triple
The composition of 4–13 was confirmed by mass spec-
bonds (Scheme 3). Compound 12 has an analogue in sulfur trometric data with a parent M+, accompanied by major
chemistry, which was synthesised by Blum et al. from the fragment ions. In their IR spectra the ν(P=Se) vibration, ob-
reaction of 1,8-bis(phenylethynyl)naphthalene with elemen- served in the range of 528–559 cm–1 for 4–11 and 13, are
tal sulfur.[21] However, we failed to obtain 12 by the reaction consistent with the published P–Se five-membered heterocy-
of 1,8-bis(phenylethynyl)naphthalene with elemental sele- cles.[8,15]
nium under identical conditions. This suggests that 12 was
The 77Se{1H} NMR spectrum of 12 shows a singlet at
1
formed from the reaction of WR and 1,8-bis(phenylethynyl)- δSe = 279.7 ppm and its H NMR spectrum displays only
naphthalene. The mechanism of this reaction must be rather aromatic protons present in a wide range at δH = 6.08–
complex and to test if 13 is involved we heated pure 13 at 9.64 ppm. Several of the 1H NMR peaks are broad at room
reflux in toluene for 5 h and obtained 12 in 18% isolated temp. which we attribute to lack of free rotation of the two
yield.
phenyl rings. The broadening is particularly pronounced for
the low field signals of the more hindered protons (see ex-
perimental section). We did carry out VT-1H experiments
and were able to sharpen the signals at 55 °C, whilst cooling
to –61 °C gave considerable broadening, but no coalescence.
The complexity of the overlapping peaks in the aromatic
region precluded detailed analysis/extraction of activation
barriers.
Attempts to grow single crystals of 4–13 for X-ray analy-
sis have, to date, been successful for only 12 and 13. The X-
ray structure of 12 shows some interesting features (Fig-
ure 3, Table 2 and Table 3). The two diselenide-bound
benzo[k]fluoranthene moieties are not parallel planes with
a dihedral angle of 162.4°, which is markedly different from
sulfur analogue [157°].[21] The two terminal phenyl rings,
which are connected to C8 and C38, respectively, are
twisted, so that the dihedral angles between them and the
two benzo[k]fluoranthene planes are 103° and 92.4° [corre-
sponding angles in the sulfur analogue 106° and 103°].[21]
Scheme 3. Synthesis of 12 and 13.
Heterocycles 4–13 are soluble in chlorinated solvents, tol-
uene, methanol and diethyl ether, with lower solubility in
hexane. They are air-stable in the solid state, however, their
solutions are not stable at room temperature; red selenium
crystals precipitated after a couple of days except for 12.
Characterisations of 4–13 were achieved by microanalysis,
IR, 1H, 13C, 31P{1H} and 77Se{1H} NMR spectroscopy and
mass spectrometry.
In the 31P{1H} NMR spectra for compounds 4–11 and
1
1
13 the magnitudes of JP,Se and JP,Se (348–380 Hz, 771–
820 Hz, respectively) are normal.[15–18] For the products in
which one CϵC triple bond has undergone P(Se)SeSe ad-
dition the 31P{1H} NMR spectra show singlets with similar
patterns of 77Se satellites. As mentioned above, in the crude
products with two C2PSe2 rings the 31P{1H} NMR spectra
Figure 3. Molecular structure of 12 (C–H bonds omitted for clar-
ity).
are mixtures as a consequence of the chirality at phospho- Table 2. Selected bond lengths [Å] and angles [°] for 12.
rus but after purification by crystallisation we were able to
Se(1)–C(1)
Se(1)–Se(31)
Se(31)–C(31)
1.920(4)
2.3699(6)
1.921(3)
C(31)–Se(31)–Se(1)
C(2)–C(1)–Se(1)
C(19)–C(1)–Se(1)
C(32)–C(31)–Se(31) 120.8(2)
C(49)–C(31)–Se(31) 120.1(2)
97.76(9)
120.8(2)
119.2(2)
obtain spectrally pure samples which also display singlets
with 77Se satellites. Compounds 4–11 and 13 were further
investigated by 77Se{1H} NMR which exhibit three signals,
assigned as C–Se, P–Se and P=Se, respectively, indicating
C(1)–Se(1)–Se(31) 97.90(9)
Eur. J. Inorg. Chem. 2007, 891–897
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
893

G. Hua, Y. Li, A. M. Z. Slawin, J. D. Woollins
FULL PAPER
Table 3. Data collection and structural refinement parameters for 2, 3, 12 and 13.
2
3
12
13
Formula
M
C14H11PSe3
447.08
C20H15PSe3
523.17
C59H38Se2
904.81
C32H21PSe3
673.34
Crystal system
Space group
a [Å]
b [Å]
c [Å]
α
β
triclinic
P1
orthorhombic
P2(1)2(1)2(1)
6.4664(5)
11.6801(9)
24.8150(19)
90
90
90
1874.2(2)
4
5.971
triclinic
P1
triclinic
P1
¯
¯
¯
7.681(3)
8.950(3)
10.713(3)
96.644(7)
94.434(7)
104.116(10)
705.2(4)
2
11.3721(8)
12.5182(9)
16.2458(13)
74.019(14)
76.960(15)
68.560(12)
2049.2(3)
2
9.4900(17)
14.217(2)
19.639(4)
95.628(5)
93.245(3)
99.543(5)
2593.4(8)
4
γ
U/A3
Z
µ [mm–1]
7.915
1.840
4.337
Reflections collected
Independent reflections (Rint
R1, wR2 [IϾ2σ(I)]
4519
2444 (0.0243)
0.0281, 0.0656
13355
3309 (0.0430)
0.0381, 0.0868
14315
8163 (0.0343)
0.0457, 0.0779
17831
9908 (0.0196)
0.0324, 0.0675
)
The structure of 13 contains two independent molecules
within the unit cell (Figure 4, Table 1 and Table 3), the rota-
tion of aryl ring C(27)–C(32) leads to some steric interac-
tions in the second independent molecule, which account
for the differences in metric parameters in the two mole-
cules. Like 2 and 3, and triselenapentalenes with carbon-
and nitrogen-containing backbones,[22,23] 13 is approxi-
mately planar; the mean deviation of P(Se)Se2C2 is 0.22 Å
[0.26 Å for molecule 2], while Se(3) lies 0.26 Å [0.30 Å for
molecule 2] out of this plane. The Se(2)–Se(3) bond length
of 2.3483(5) Å [2.3474(5) Å for molecule 2] is identical to
that in PhP(Se)Se2-containing five membered ring.[15,18]
In order to gain some mechanistic insight, we examined
the 31P{1H} and 77Se NMR of a crude reaction mixture
during the reaction of phenylacetylene with WR. Apart
from the major product 2 [δ = 67.1 ppm] there are several
smaller doublets centred at δ = 76.2, 58.1, 40.1, 9.2,
–15.7 ppm indicating different phosphorus environments
present in the reaction mixture. None of these values corres-
Figure 4. Molecular structure of one of the independent molecules
in 13 (C–H bonds omitted for clarity).
Scheme 4. Suggested mechanism for the formation of 2–11 and 13.
894
www.eurjic.org
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2007, 891–897

Vinylic P–Se Heterocycles
FULL PAPER
pond to known Ph–P–Se rings[9] or WR [δP (solid state) =
18.7 ppm] The 31P-31P coupling, typically ca. 270 Hz, along
with 31P-77Se coupling constant of ca. 220 Hz, suggest
P–P–Se or P–Se–P linkages but does not provide any dis-
criminatory evidence. The 77Se NMR showed Ͼ95% of the
selenium present as the product 2 with only a very weak
doublet at δSe = –308 ppm (J = 765 Hz) and a singlet at
δSe = 317 ppm. We can only speculate on a mechanism. At
elevated temperatures 1 is believed to be in equilibrium with
tion. Upon cooling to room temperature the solution was column-
chromatographed (silica gel, toluene as eluent) to give a brown
fraction of 2, which was crystallised from dichloromethane/hexane.
Yield 401 mg, 91%. C14H11PSe3 (447.09): calcd. C 37.6, H 2.5;
1
found C 37.7, H 2.6. IR (KBr): ν = 523 (s, νP=Se) cm–1. H NMR:
˜
δ = 8.29 (m, 2 H, Ph), 7.75 (m, 2 H, Ph), 7.65 (m, 3 H, Ph), 7.56
2
(m, 3 H, Ph), 7.26 (d, JP,H = 34 Hz, 1 H, =C–H) ppm. 13C NMR:
δ = 132.7, 131.9, 131.7, 131.0, 129.3, 128.8, 128.6, 127.9, 121.9,
1
120.7 ppm. 31P NMR: δ = 67.1 (s, JP,Se = 350 Hz, 1JP,Se = 771 Hz)
2
1
ppm. 77Se NMR: δ = 559.9 (d, JP,Se = 7 Hz), 411.7 (d, JP,Se
=
1
a diselenaphosphorane PhPSe2, which is the true reactive 350 Hz), –15.4 (d, JP,Se = 774 Hz) ppm. MS (CI): m/z = 448 [M +
H]+.
species in refluxing solution. The first step in the reaction
is a [2 + 2] cycloaddition of a P=Se bond from PhPSe2
across the CϵC bond, giving an intermediate I, which exists
in equilibrium in solution in two forms: the 1,2-selenaphos-
phacyclobutene I and the dipolar species II. We speculate
that the latter species II can react with PhPSe2 to give a
second dipolar intermediate III, which rapidly eliminates
[PhPSe]n to cyclise to subsequently afford 2–11 and 13
(Scheme 4).
In conclusion, we have successfully used Woollins’ rea-
gent for the syntheses of a series of novel vinylic P–Se
heterocycles from alkyl CϵC triple bond organic substrates.
Using 1H, 31P{1H} and 77Se{1H} NMR spectroscopy in
conjunction with single-crystal X-ray crystallography we
have elucidated the structures of the novel heterocycles.
3,4,5-Triphenyl-3H-1,2,3-diselenaphosphole 3-Selenide (3): A re-
fluxing mixture of diphenylacetylene (0.18 g, 1 mmol) and WR
(0.54 g, 1 mmol) in toluene was heated at 130 °C over 12 h to give
a brown solution. Upon cooling to room temperature the solution
was column-chromatographed (silica gel, toluene as eluent) to give
an orange crystal of 3, which was crystallised from dichlorometh-
ane/hexane. Yield 495 mg, 94 %. C20H15PSe3 (523.19): calcd. C
45.9, H 2.9; found C 45.8, H 3.1. IR (KBr): ν = 539 (s, νP=Se) cm–1.
˜
1H NMR: δ = 8.13 (m, 2 H, Ph), 7.45 (m, 3 H, Ph), 7.24 (m, 5 H,
Ph), 7.01 (m, 5 H, Ph) ppm. 1H NMR: δ = 132.6, 132.4, 132.2,
130.7, 130.6, 129.8, 128.7, 128.6, 128.4, 128.2, 127.8 ppm. 31P
1
1
NMR: δ = 74.3 (s, JP,Se = 357 Hz, JP,Se = 779 Hz) ppm. 77Se
NMR: δ = 519.3 (d, 2JP,Se = 7 Hz), 373.4 (d, 1JP,Se = 358 Hz), –28.6
(d, JP,Se = 777 Hz) ppm. MS (ES+): m/z (%) = 546 [M + Na]+.
1
3,4-Diphenyl-5-[4-(phenylethynyl)phenyl]-3H-1,2,3-diselenaphos-
phole 3-Selenide (4) and 5,5Ј-(1,4-Phenylene)bis(3,4-diphenyl-3H-
1,2,3-diselenaphosphole) 3,3Ј-Diselenide (5): A solution of WR
(1.08 g, 2 mmol) and 1,4-bis(phenylethynyl)benzene (0.28 g,
1 mmol) in toluene (10 cm3) in a sealed tube was refluxed for 12 h,
giving a yellow solution. Upon cooling to room temperature, the
toluene solution was purified by column chromatography (silica
gel, toluene as eluent) to afford a yellow fraction of 4 followed by
another orange band, which was proved to be a mixture of confor-
mational isomers by 31P NMR spectroscopy. Layering a dichloro-
methane solution of the mixture with hexane gave a major orange
powder of 5a.
Experimental Section
Unless otherwise stated, all reactions were carried out under oxy-
gen-free nitrogenusing pre-dried solvents and standard Schlenk
techniques, subsequent chromatographic and work-up procedures
were performed in air. Solvents were dried, purified, and stored
according to common procedures.[24] 1,4-Bis(phenylethynyl)ben-
zene,[25] 1,2-bis(phenylethynyl)benzene,[26] 1,3-bis(phenylethynyl)-
benzene,[27] and 1,8-bis(phenylethynyl)naphthalene[28] were synthe-
sised according to the literature methods.
1H (270 Hz), 13C (67.9 Hz), 31P{1H} (109 Hz) and 77Se{1H}
(51.4 Hz referenced to external Me2Se) NMR spectra were re-
corded in CDCl3 at 25 °C (unless stated otherwise) with a JEOL
GSX 270. IR spectra were recorded as KBr pellets in the range of
4000–250 cm–1 with a Perkin–Elmer 2000 FTIR/Raman spectrome-
ter. Microanalysis was performed by the University of St Andrews
microanalysis service. Mass spectrometry was performed by the
EPSRC National Mass Spectrometry Service Centre, Swansea and
the University of St Andrews Mass Spectrometry Service.
Compound 4: Yield 180 mg, 29%. C28H19PSe3 (623.30): calcd. C
54.0, H 3.1; found C 53.4, H 3.7. IR (KBr): ν = 539 (s, νP=Se) cm–1.
˜
1
1H NMR: δ = 7.29–8.15 (m, 19 H, Ph) ppm. H NMR: δ = 140.6,
139.6, 134.8, 134.0, 133.0, 132.8, 132.6, 132.4, 132.2, 131.9, 129.8,
128.7, 128.6, 128.5, 128. 3, 125.4, 121.8, 121.4, 104.1, 83.6, 83.2,
1
1
81.7, 74.0 ppm. 31P NMR: δ = 73.9 (s, JP,Se = 357 Hz, JP,Se
=
2
779 Hz) ppm. 77Se NMR: δ = 519.8 (d, JP,Se = 7 Hz), 382.3 (d,
1JP,Se = 355 Hz), –16.4 (d, JP,Se = 779 Hz) ppm. MS (EI): m/z =
1
623 [M]+, 278 [M – PhPSe3]+.
Compound 5a: Yield 105 mg, 11%. C34H24P2Se6 (968.26): calcd. C
X-ray crystal data for 2, 3, 12 and 13 (Table 2 and Table 3) were
collected at 93 K with a Rigaku MM007 High brilliance RA gener-
ator and Mercury CCD system. Intensities were corrected for Lo-
rentz polarisation and for absorption. The structures were solved
by direct methods. Hydrogen atoms bound to carbon were ideal-
ised. Structural refinements were obtained with full-matrix least
squares based on F2 by using the program SHELXTL.[29]
42.2, H 2.5; found C 42.7, H 2.5. IR (KBr): ν = 559 (s, νP=Se) cm–1.
˜
1
1H NMR: δ = 6.94–8.09 (m, 24 H, Ph) ppm. H NMR: δ = 132.4,
132.3, 132.2, 132.0, 130.5, 130.2, 130.1, 129.9, 129.6, 128.7, 128.5,
1
128.4, 128.2, 128.0, 127.6 ppm. 31P NMR: δ = 73.3 (s, JP,Se
=
=
1
2
357 Hz, JP,Se = 774 Hz) ppm. 77Se NMR: δ = 522.9 (d, JP,Se
1
1
7 Hz), 384.7 (d, JP,Se = 355 Hz), –16.3 (d, JP,Se = 773 Hz) ppm.
MS (EI): m/z = 968 [M]+, 278 [M – 2PhPSe3]+.
CCDC-6139164 to -613917 contain the supplementary crystallo-
graphic data for this paper. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif.
3,4-Diphenyl-5-[3-(phenylethynyl)phenyl]-3H-1,2,3-diselenaphos-
phole 3-Selenide (6) and 5,5Ј-(1,3-Phenylene)bis(3,4-diphenyl-3H-
1,2,3-diselenaphosphole) 3,3Ј-Diselenide (7): WR (1.08 g, 2 mmol)
and 1,3-bisphenylethynylbenzene (0.28 g, 1 mmol) were stirred in
10 cm3 of dry toluene at 130 °C in a sealed tube for 12 h, producing
3,5-Diphenyl-1,2,3-diselenaphosphole 3-Selenide (2): A mixture of
phenylacetylene (0.10 g, 1 mmol) and WR (0.54 g, 1 mmol) in a dark yellow solution plus a tiny amount of black solid (selenium,
10 cm3 of dry toluene was refluxed over 12 h to give a brown solu-
resulted from the decomposition of WR). Column chromatography
Eur. J. Inorg. Chem. 2007, 891–897
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
895

G. Hua, Y. Li, A. M. Z. Slawin, J. D. Woollins
FULL PAPER
1
(silica gel, toluene as eluent) produced a yellow fraction of 6 and
subsequent another yellow band whose 31P{1H} NMR spectrum
revealed a mixture of conformational isomers. Layering a dichloro-
methane solution of the mixture with hexane gave a yellow powder
of 7a.
1H NMR: δ = 6.66–8.56 (m, 23 H, Ph) ppm. H NMR: δ = 134.5,
134.3, 133.2, 133.0, 132.4, 132.1, 131.5, 130.1, 129.1, 128.8, 128.5,
128.2, 128.0, 127.1, 127.0, 126.7, 126.3, 126.0, 123.2, 119.8 ppm.
1
1
31P NMR: δ = 73.3 (s, JP,Se = 352 Hz, JP,Se = 794 Hz) ppm. 77Se
NMR: δ = 529.3 (d, 2JP,Se = 7 Hz), 414.4 (d, 1JP,Se = 353 Hz), –19.6
(d, JP,Se = 792 Hz) ppm. MS (CI): m/z = 727 [M + H]+, 378 [M –
1
Compound 6: Yield 360 mg, 58%. C34H24P2Se6 (968.26): calcd. C
PhPSe3]+.
54.0, H 3.1; found C 53.7, H 3.2. IR (KBr): ν = 532 (s, νP=Se) cm–1.
˜
1H NMR: δ = 6.95–8.18 (m, 19 H, Ph) ppm. H NMR: δ = 135.5,
1
Compound 11a: Yield 183 mg, 17%. C34H24P2Se6 (968.26): calcd.
135.3, 134.6, 134.3, 133.5, 133.5, 132.7, 132.5, 132.2, 131.7, 131.6,
131.1, 130.7, 130.6, 130.0, 129.7, 129.3, 128.8, 128.4, 128.3,
C 47.2, H 2.6; found C 46.7, H 2.7. IR (KBr): ν = 533 (s, ν
)
˜
P=Se
cm–1. H NMR: δ = 6.63–8.26 (m, 28 H, Ph) ppm. H NMR: δ =
1
1
1
122.8 ppm. 31P NMR: δ = 74.3 (s, JP,Se = 356 Hz, 1JP,Se = 778 Hz)
133.2, 132.9, 132.8, 132.2, 132.0, 131.7, 129.9, 129.1, 128.7, 128.5,
2
1
ppm. 77Se NMR: δ = 520.7 (d, JP,Se = 7 Hz), 379.4 (d, JP,Se
=
1
127.9, 127.4, 127.0, 126.0 ppm. 31P NMR: δ = 73.3 (s, JP,Se
=
=
358 Hz), –25.3 (d, JP,Se = 777 Hz) ppm. MS (EI): m/z = 623 [M]+,
278 [M – PhPSe3]+.
1
1
2
352 Hz, JP,Se = 779 Hz) ppm. 77Se NMR: δ = 535.2 (d, JP,Se
1
1
7 Hz), 404.0 (d, JP,Se = 355 Hz), –16.8 (d, JP,Se = 780 Hz) ppm.
MS (CI): m/z = 1069 [M + H]+, 726 [M – PhPSe3]+, 565 [M –
PhPSe3 – 2Se or 2Ph]+, 378 [M – 2PhPSe3]+.
Compound 7a: Yield 175 mg, 18%. C34H24P2Se6 (968.26): calcd. C
42.2, H 2.5; found C 42.8, H 2.2. IR (KBr): ν = 538 (s, νP=Se) cm–1.
˜
1
1H NMR: δ = 7.13–8.06 (m, 24 H, Ph) ppm. H NMR: δ = 132.0,
Synthesis of Diselane 12 and 3,4-Diphenyl-5-[8-(phenylethynyl)-1-
naphthyl]-3H-1,2,3-diselenaphosphole 3-Selenide (13): A mixture of
Woollins’ reagent (1.08 g, 2 mmol) and 1,8-bis(phenylethynyl)naph-
thalene (0.45 g, 1 mmol) in toluene (20 cm3) was heated at reflux
for 12 h resulting in red solution. After cooling to room tempera-
ture, the solution was subjected to column chromatography (SiO2,
toluene as eluent) and afforded successively red 12 followed a pale
yellow 13.
129.9, 129.7, 128.8, 128.7, 128.6, 128.5, 128.4 ppm. 31P NMR: δ =
1
1
74.28 (s, JP,Se = 352 Hz, JP,Se = 771 Hz) ppm. 77Se NMR: δ =
2
1
1
525.0 (d, JP,Se = 7 Hz), 381.9 (d, JP,Se = 354 Hz), –14.6 (d, JP,Se
= 771 Hz) ppm. MS (EI): m/z = 968 [M]+, 546 [M – Ph or Se –
PhPSe3]+, 278 [M – 2PhPSe3]+.
3,4-Diphenyl-5-[2-(phenylethynyl)phenyl]-3H-1,2,3-diselenaphos-
phole 3-Selenide (8) and 5,5Ј-(1,2-Phenylene)bis(3,4-diphenyl-3H-
1,2,3-diselenaphosphole) 3,3Ј-Diselenide (9): 1,2-Bis(phenylethynyl)-
benzene (0.28 g, 1 mmol) and WR (1.08 g, 2 mmol) in toluene
(10 cm3) were refluxed for 12 h, giving a brownish yellow solution.
Column chromatography (silica gel, toluene) gave a yellow fraction
of 8 followed by a yellow band whose 31P{1H} NMR spectrum
revealed a mixture of conformational isomers once again. Layering
a dichloromethane solution of the mixture with hexane afforded a
yellow powder of 9a.
Compound 12: Yield 57 mg, 14%. C52H30Se2 (812.71): calcd. C
76.8, H 3.7; found C 76.1, H 3.9. IR (KBr): ν = 825 (w), 759 (m),
˜
1
701 (w), 448 (w) cm–1. H NMR: δ = 6.08 (br., d, 1 H, Ph), 6.56–
1
8.67 (br., m, 28 H, Ph), 9.64 (br., d, 1 H, Ph) ppm. H NMR: δ =
135.7, 135.0, 134.2, 132.1, 131.7, 130.0, 129.9, 129.7, 129.3, 128.9,
128.0, 127.9, 125.7, 124.9, 124.8, 123.9, 122.3, 121.7, 120.9, 119.9,
119.1, 118.8 ppm. 77Se NMR: δ = 279.7 (s, 2Se) ppm. MS (CI): m/z
= 831 [M + NH4]+.
Compound 8: Yield 437 mg, 70%. C34H24P2Se6 (968.26): calcd. C
Compound 13: Yield 147 mg, 22%. C32H21PSe3 (673.36): calcd. C
54.0, H 3.1; found C 54.2, H 3.8. IR (KBr): ν = 539 (s, νP=Se) cm–1.
57.1, H 3.1; found C 57.7, H 3.3. IR (KBr): ν = 546 (s, νP=Se) cm–1.
˜
˜
1
1H NMR: δ = 6.98–7.67 (m, 19 H, Ph) ppm. H NMR: δ = 133.6,
1
1H NMR: δ = 6.81–8.70 (m, 21 H, Ph) ppm. H NMR: δ = 135.6,
133.3, 132.5, 132.3, 132.1, 132.0, 131.9, 131.4, 130.5, 129.7, 129.2,
134.0, 133.0, 132.4, 131.4, 131.0, 130.9, 130.0, 129.5, 129.4, 128.9,
129.0, 128.7, 128.5, 128.1, 128.0, 127.7 ppm. 31P NMR: δ = 73.8
1
128.7, 128.5, 127.3, 126.1, 125.8 ppm. 31P NMR: δ = 66.5 (s, JP,Se
1
1
(s, JP,Se = 343 Hz, JP,Se = 779 Hz) ppm. 77Se NMR: δ = 528.6 (d,
1
2
= 380 Hz, JP,Se = 803 Hz) ppm. 77Se NMR: δ = 564.9 (d, JP,Se
=
2JP,Se = 7 Hz), 409.8 (d, JP,Se = 346 Hz), –22.2 (d, 1JP,Se = 778 Hz)
1
1
1
11 Hz), 461.5 (d, JP,Se = 383 Hz), –14.7 (d, JP,Se = 802 Hz) ppm.
MS (CI+): m/z = 674 [M + H]+, 436 [M – 3Se or 3Ph]+, 328 [M –
PhPSe3]+.
ppm. MS (EI): m/z = 623 [M]+, 278 [M – PhPSe3]+.
Compound 9a: Yield 144 mg, 15%. C34H24P2Se6 (968.26): calcd. C
42.2, H 2.5; found C 42.7, H 2.6. IR (KBr): ν = 528 (s, νP=Se) cm–1.
˜
1
1H NMR: δ = 7.00–7.41 (m, 24 H, Ph) ppm. H NMR: δ = 133.6,
Acknowledgments
133.4, 132.5, 132.3, 132.1, 131.9, 131.4, 130.6, 129.7, 129.2, 128.7,
1
128.5, 128.2, 128.1, 127.7 ppm. 31P NMR: δ = 77.5 (s, JP,Se
=
=
1
2
We are grateful to the Engineering and Physical Sciences Research
Council (EPSRC) (U. K.) for funding.
364 Hz, JP,Se = 822 Hz) ppm. 77Se NMR: δ = 528.4 (d, JP,Se
1
1
8 Hz), 409.8 (d, JP,Se = 365 Hz), –21.9 (d, JP,Se = 820 Hz) ppm.
MS (EI): m/z = 968 [M]+ , 624 [M – PhPSe3 ]+ , 278 [M –
2PhPSe3]+.
[1] G. L. Sommen, A. Linden, H. Heimgartner, Helv. Chim. Acta
2005, 88, 766–773.
[2] T. Wirth, Tetrahedron 1999, 55, 1–28; Y. Xu, E. T. Kool, J. Am.
Chem. Soc. 2000, 122, 9040–9041.
[3] Y. Ogasawara, G. Lacourciere, T. C. Stadtman, Proc. Natl.
Acad. Sci. USA 2001, 98, 9494–9498.
[4] H. E. Ganther, Bioorg. Med. Chem. 2001, 9, 1459–1466.
[5] G. Mugesh, W.-W. Du Mont, H. Sies, Chem. Rev. 2001, 101,
2125–2179.
[6] P. Ximenez-Embun, I. Alonso, Y. Madrid-Albarran, C. Cam-
ara, J. Agric. Food Chem. 2004, 52, 832–838.
[7] D. B. Vickerman, J. T. Trumble, G. N. George, I. J. Pickering,
H. Nichol, Environ. Sci. Technol. 2004, 38, 3581–3586.
[8] I. P. Gray, P. Bhattacharyya, A. M. Z. Slawin, J. D. Woollins,
Chem. Eur. J. 2005, 11, 6221–6227.
3,4-Diphenyl-5-[10-(phenylethnyl)anthracen-9-yl]-3H-1,2,3-diselena-
phosphole 3-Selenide (10) and 5,5Ј-Anthracene-9,10-diylbis(3,4-di-
phenyl-3H-1,2,3-diselenaphosphole) 3,3Ј-Diselenide (11): A solution
of WR (1.08 g, 2 mmol) and bis(phenylethynyl)anthracene (0.38 g,
1 mmol) in toluene (10 cm3) in a sealed tube was refluxed for 12 h,
giving a yellow solution. After cooling to room temperature the
toluene solution was purified by column chromatography (SiO2,
toluene as eluent) to afford a yellow fraction of 10 followed by
another orange band of the mixture. Layering a dichloromethane
solution of the mixture with hexane gave orange powder of 11a.
Compound 10: Yield 410 mg, 57%. C36H23P2Se6 (991.28): calcd. C
59.8, H 3.2; found C 59.9, H 3.4. IR (KBr): ν = 533 (s, νP=Se) cm–1.
˜
896
www.eurjic.org
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2007, 891–897

Vinylic P–Se Heterocycles
FULL PAPER
[9] J. C. Fitzmaurice, D. J. Williams, P. T. Wood, J. D. Woollins, J.
Chem. Soc., Chem. Commun. 1988, 741–743; P. T. Wood, J. D.
Woollins, J. Chem. Soc., Chem. Commun. 1988, 1190–1191;
M. J. Pilkington, A. M. Z. Slawin, D. J. Williams, P. T. Wood,
J. D. Woollins, Heteroatom Chem. 1990, 1, 351–355.
[10] I. Baxter, A. F. Hill, J. M. Malget, A. J. P. White, J. D. Williams,
Chem. Commun. 1997, 2049–2050.
[11] P. Bhattacharyya, J. D. Woollins, Tetrahedron Lett. 2001, 42,
5949–5951.
[12] J. Bethke, K. Karaghiosoff, L. A. Wessjohann, Tetrahedron
Lett. 2003, 44, 6911–6913.
[19]
P. Bhattacharyya, J. Novosad, J. R. Phillips, A. M. Z. Slawin,
D. J. William, J. D. Woollins, J. Chem. Soc., Dalton Trans. 1995,
1607–1613.
D. L. An, N. Higeta, K. Toyota, M. Yoshifuji, Chem. Lett.
1998, 17–18 and references cited therein.
J. Blum, Y. Badrieh, O. Shaaya, L. Meltser, Phosphorus Sulfur
Silicon Relat. Elem. 1993, 79, 87–96.
R. Richter, J. Sieler, L. K. Hansen, R. Koehler, L. Beyer, E.
[20]
[21]
[22]
[23]
[24]
Hoyer, Acta Chem. Scand. 1991, 45, 1–5.
A. Hordvik, K. Julshamn, Act Chem. Scand. 1971, 25, 2507–
2515.
[13] G. Hua, Y. Li, A. M. Z. Slawin, J. D. Woollins, Org. Lett. 2006,
8, 5251–5254.
D. D. Perrin, W. L. F. Armarego, Purification of Laboratory
[14] I. P. Gray, H. L. Milton, A. M. Z. Slawin, J. D. Woollins, Dal-
ton Trans. 2003, 3450–3457; I. P. Gray, A. M. Z. Slawin, J. D.
Woollins, New J. Chem. 2004, 28, 1383–1389; I. P. Gray,
A. M. Z. Slawin, J. D. Woollins, Dalton Trans. 2004, 2477–
2486; I. P. Gray, A. M. Z. Slawin, J. D. Woollins, Z. Anorg.
Allg. Chem. 2004, 630, 1851–1857; I. P. Gray, A. M. Z. Slawin,
J. D. Woollins, Dalton Trans. 2005, 2188–2194.
Chemicals, 3rd ed., Pergamon Press, Oxford, 1988.
[25] P. Nguyen, Z. Yuan, L. Agocs, G. Lesley, T. B. Marder, Inorg.
Chim. Acta 1994, 220, 289–296.
[26] S. V. Kovalenko, S. Peabody, M. Manoharan, R. J. Clark, I. V.
Alabugin, Org. Lett. 2004, 6, 2457; J. A. John, J. M. Tour, Tet-
rahedron 1997, 53, 15515–15534.
[27] T. Kawase, N. Ueda, H. R. Darab, M. Oda, Angew. Chem. Int.
Ed. Engl. 1996, 35, 1556; C. J. F. Du, H. Hart, J. Org. Chem.
1987, 52, 4311–4314.
[15] P. Bhattacharyya, A. M. Z. Slawin, J. D. Woollins, Chem. Eur.
J. 2002, 8, 2705–2711.
[16] P. Bhattacharyya, A. M. Z. Slawin, J. D. Woollins, Angew.
Chem. Int. Ed. 2000, 39, 1973–1975.
[17] P. Bhattacharyya, A. M. Z. Slawin, J. D. Woollins, J. Or-
ganomet. Chem. 2001, 623, 116–119.
[18] P. Bhattacharyya, A. M. Z. Slawin, J. D. Woollins, J. Chem.
Soc., Dalton Trans. 2001, 300–303.
[28] B. Bossenbroek, D. C. Sanders, H. M. Curry, H. Shechter, J.
Am. Chem. Soc. 1969, 91, 371–379.
[29] G. M. Sheldrick, SHELXTL 6.10, Bruker AXS, Madison, WI,
2002.
Received: November 14, 2006
Published Online: January 10, 2007
Eur. J. Inorg. Chem. 2007, 891–897
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
897