Reactions of sodium 3,4,5-triphenyl-1,2-diphosphacyclopentadienide with alkyl halides and silicon and tin chlorides

Article abstract of DOI:10.1007/s11172-010-0226-9

Reactions of sodium 3,4,5-triphenyl-1,2-diphosphacyclopentadienide with primary alkyl bromides, secondary alkyl iodides, and silicon and tin chlorides gave stable 1-substituted 1,2-diphospholes. In a solution of 3,4,5-triphenyl-1-trimethylstannyl-1,2-diphosphacyclopenta-2,4-diene, the Me3Sn group migrates between two phosphorus atoms.

Full text of DOI:10.1007/s11172-010-0226-9

Russian Chemical Bulletin, International Edition, Vol. 59, No. 6, pp. 1232—1236, June, 2010
1232
Reactions of sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentadienide
with alkyl halides and silicon and tin chlorides*
V. A. Milyukov,a I. A. Bezkishko,a A. A. Zagidullin,a O. G. Sinyashin,a and E. HeyꢀHawkinsb
aA. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Research Center of the Russian Academy of Sciences,
8 ul. Akad. Arbuzova, 420088 Kazan, Russian Federation.
Eꢀmail: miluykov@iopc.knc.ru
bInstitute of Inorganic Chemistry, Leipzig University,
29 Johannisallee, Dꢀ04103 Leipzig, Germany.**
Eꢀmail: hey@rz.uniꢀleipzig.de
Reactions of sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentadienide with primary alkyl
bromides, secondary alkyl iodides, and silicon and tin chlorides gave stable 1ꢀsubstituted
1,2ꢀdiphospholes. In a solution of 3,4,5ꢀtriphenylꢀ1ꢀtrimethylstannylꢀ1,2ꢀdiphosphacyclopentaꢀ
2,4ꢀdiene, the Me3Sn group migrates between two phosphorus atoms.
Key words: sodium 1,2ꢀdiphosphacyclopentadienide, phospholes, alkyl halides, organosiliꢀ
con chlorides, organotin chlorides.
Phosphacyclopentadienes (phospholes), the phosꢀ
phorus analogs of cyclopentadiene, are attractive synꢀ
thons for the synthesis of phosphorusꢀcontaining polycyꢀ
clic compounds, phosphacyclopentadienide anions, phosꢀ
phametallocenes, phosphabenzene, etc.1,2 Cycloaddition
reactions involving phosphacyclopentadienes have been
used to obtain novel chiral framework compounds of phosꢀ
phorus, viz., phosphanorbornenes and phosphanorbornaꢀ
dienes, which are employed as ligands for homogeneous,
biphasic, and asymmetric catalysis of organic reacꢀ
tions such as the Heck reaction,3 enantioselective hydroꢀ
genation,4 Cꢀ and Nꢀalkylation,5 and hydroformylation of
olefins.6,7
tautomeric forms: they are thermally stable like 1Rꢀphosꢀ
pholes and are highly reactive in cycloaddition reactions
like 2Rꢀphospholes.
In connection with this, for development of an apꢀ
proach to the synthesis of novel 1ꢀsubstituted 1,2ꢀdiphosꢀ
pholes, it was interesting to study in more detail the reacꢀ
tivity of sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopenꢀ
tadienide (1) toward primary, secondary, and tertiary alkyl
halides, as well as toward silicon(IV) and tin(IV) chlorides.
We found that sodium 1,2ꢀdiphosphacyclopentadienꢀ
ide 1 reacts with primary alkyl bromides in THF at –80 °C
to form 1ꢀalkylꢀ1,2ꢀdiphosphacyclopentaꢀ2,4ꢀdienes 2 in
50—60% yields (Scheme 1).
Among phospholes, the chemical behavior of monoꢀ
phosphacyclopentadienes is now best studied; for instance,
their two tautomeric forms (1Rꢀ and 2Rꢀphospholes) are
known to differ greatly in reactivity and stability. Being
thermally stable, 1Rꢀphospholes are inert in cycloaddition
reactions: only under harsh conditions do they react to
give target products in low yields. In contrast, 2Rꢀphospꢀ
holes, which are formed from 1Rꢀphospholes at high temꢀ
peratures via R[1,5]ꢀsigmatropic shift, contain the highly
reactive P=C bond and easily react with both dienes and
dienophiles.8 Earlier,9 we have demonstrated that 1ꢀalkylꢀ
3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentaꢀ2,4ꢀdienes
(1ꢀalkylꢀ1,2ꢀdiphospholes) combining the fragments of
1Rꢀ and 2Rꢀphospholes are chemically similar to both
Scheme 1
* Dedicated to Academician I. L. Eremenko on the occasion of
his 60th birthday.
Hal = Br: R = Me (a), Et (b), Bui (c), Bun (d);
** Institut für anorganische Chemie der Universität Leipzig,
29 Johannisallee, Dꢀ04103 Leipzig, Deutschland.
Hal = I: R = Pri (e),
(f)
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1206—1210, June, 2010.
1066ꢀ5285/10/5906ꢀ1232 © 2010 Springer Science+Business Media, Inc.

Reactions of sodium 1,2ꢀdiphospholide with RHal
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 6, June, 2010
1233
The structures of the obtained compounds were proved
by 1H, 13C, and 31P NMR spectroscopy. For instance, the
31P{1H} NMR spectra of 1ꢀalkylꢀ3,4,5ꢀtriphenylꢀ1,2ꢀ
diphosphacyclopentaꢀ2,4ꢀdienes show two doublets at
~200 and ~70 ppm (1JP,P ≈ 400 Hz) characteristic of the
sp2ꢀ and sp3ꢀhybridized P atoms, respectively. In the
13C NMR spectrum, the signal for the C(1) atom at the
double P=C(1) bond appears as a doublet of doublets because
of a coupling with two nonequivalent phosphorus nuclei.
Trimethyltin chloride shows similar reactivity in a reꢀ
action with compound 1. The 31P{1H} NMR spectrum of
3,4,5ꢀtriphenylꢀ1ꢀtrimethylstannylꢀ1,2ꢀdiphosphacycloꢀ
pentaꢀ2,4ꢀdiene (4) at ~20 °C contains a broad singlet at
116 ppm (the halfꢀwidth of the signal is 41.7 Hz) with two
satellites arising from couplings between the P and Sn
nuclei. The 119Sn NMR spectrum at ~20 °C shows a triꢀ
plet with a central signal at 51 ppm (1JSn,P = 276 Hz). This
suggests dynamic processes in a solution of compound 4
that are associated with the migration of the Me3Sn group
between the phosphorus atoms. Earlier, similar fluctuaꢀ
tions of the trimethylstannyl group have been observed for
tin derivatives of 1,2,4ꢀtriphosphacyclopentaꢀ2,4ꢀdiꢀ
ene.10,11
Additional evidence for the fluctuations of the Me3Sn
group was obtained in the study of the temperature depenꢀ
dence of the 31P{1H} NMR spectrum of compound 4 in
THFꢀd8 (Fig. 1).
However, sodium 1,2ꢀdiphosphacyclopentadienide 1
does not react with secondary alkyl bromides under simiꢀ
lar conditions: the starting reagents were recovered unꢀ
changed from the reaction mixture. Only the use of secꢀ
ondary alkyl iodides allowed us to obtain novel 1ꢀalkylꢀ
1,2ꢀdiphospholes 1e,f in 40—45% yields. Note that tertꢀ
butyl iodide is unable to alkylate compound 1; i.e., the
reaction is sensitive to the bulkiness of the electrophilic
reagent.
An interesting goal in the context of these investigaꢀ
tions was to obtain 1,2ꢀdiphospholes containing the Me3Si
(or Me3Sn) group at the P atom, since such phospholes
seem to be convenient reagents for introduction of a 1,2ꢀdiꢀ
phosphacyclopentadienide ligand into transition metal
complexes. We found that chlorotrimethylsilane reacts
with sodium 1,2ꢀdiphosphacyclopentadienide 1 in THF
at –80 °C to give 3,4,5ꢀtriphenylꢀ1ꢀtrimethylsilylꢀ1,2ꢀ
diphosphacyclopentaꢀ2,4ꢀdiene (3) (Scheme 2). The
31P{1H} NMR spectrum of compound 3 exhibits two douꢀ
blets at 212 and 67 ppm with 1JP,P = 413.5 Hz.
For instance, the signal disappears from the spectrum
at 183 K, thus suggesting the coalescence temperature is
reached. The calculated12 Gibbs energy of activation
of the Me3Sn exchange between two P atoms is ΔG≠
=
= 34.9 1 kJ mol–1, which is comparable with the energy
of activation for tin derivatives of 1,2,4ꢀtriphosphaꢀ
cyclopentaꢀ2,4ꢀdiene (31.5 kJ mol–1).10 At 165 K, the
spectrum exhibits two broad signals at ~220 and ~30 ppm
because of the stabilization of one tautomeric form. Unꢀ
fortunately, freezing of the solvent upon further cooling
precluded the determination of the coupling constant.
Additional evidence for the fluctuating character of
the P—Sn bond was obtained in the attempted synthesis of
dimethylbis(3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentaꢀ
2,4ꢀdienꢀ1ꢀyl)stannane (6). We found that a reaction of
Me2SnCl2 with two equivalents of compound 1 gives
a mixture of monoꢀ (5) and disubstituted products (6), in
which the Cl atoms are replaced by the 3,4,5ꢀtriphenylꢀ
1,2ꢀdiphosphacyclopentadienyl fragments (Scheme 3).
Scheme 2
1
2
3
200
150
100
50
0 δ
Fig. 1. 31P NMR spectra of 3,4,5ꢀtriphenylꢀ1ꢀtrimethylstannylꢀ
1,2ꢀdiphosphacyclopentadiene (4) at 298 (1), 183 (2), and
165 K (3).

1234
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 6, June, 2010
Milyukov et al.
Scheme 3
phacyclopentadienide (1) (0.81 g, 1.31 mmol) and bromoꢀ
methane (0.15 g, 1.57 mmol, 20% excess). The yield of comꢀ
pound 2a was 0.27 g (61%), light yellow oil. Found (%):
C, 76.89; H, 5.33; P, 17.79. C22H18P2. Calculated (%): C, 76.74;
H, 5.27; P, 17.99. 1H NMR (C6D6), δ: 1.41 (m, 3 H, Me);
Our numerous attempts to separate this mixture failed.
Nevertheless, the yield of product 6 was increased to 60%
upon heating its mixture with compound 5 in vacuo at
120 °C with simultaneous removal of Me2SnCl2.
To sum up, we demonstrated that the reactions of soꢀ
dium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentadienide
with primary alkyl bromides, secondary alkyl iodides, chloꢀ
rotrimethylsilane, and trimethyltin chloride afford 1ꢀsubꢀ
stituted 1,2ꢀdiphospholes. In 1ꢀtrimethylstannylꢀ1,2ꢀ
diphosphole 4, the P—Sn bond is labile, which is evident
from the tautomeric shift of the Me3Sn fragment between
the phosphorus atoms.
6.74—7.16 (m, 15 H, Ph). 31P NMR (C6D6), δ: 218.44 (d, 1JP,P
=
= 4108.36 Hz); 47.09 (d, 1JP,P = 410.36 Hz). 13C NMR (C6D6),
1
2
δ: 15.35 (dd, Me, JC,P = 44.23 Hz, JC,P = 13.34 Hz); 125.87
(s, C(11)); 126.32 (s, C(15)); 126.47 (s, C(7)); 127.12 (s, C(6));
3
127.98 (s, C(10)); 128.26 (s, C(14)); 128.69 (dd, C(5), JC,P
=
4
3
= 13.13 Hz, JC,P = 1.58 Hz); 129.62 (d, C(13), JC,P = 10.45
Hz); 132.38 (t, C(8), 3JC,P = 7.92 Hz); 137.66 (d, C(9), 4JC,P
= 4.12 Hz); 139.45 (dd, C(4), 2JC,P = 11.33 Hz, 3JC,P = 3.69 Hz);
=
2
2
144.07 (d, C(12), JC,P = 17.88 Hz); 151.67 (t, C(2), JC,P
=
= 17.38 Hz); 166.23 (dd, C(3), 1JC,P = 11.12 Hz, 2JC,P = 5.04 Hz);
197.37 (dd, C(1), 1JC,P = 59.28 Hz, 2JC,P = 11.19 Hz).
Experimental
1ꢀEthylꢀ3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentaꢀ2,4ꢀdiene
(2b) was obtained from sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosꢀ
phacyclopentadienide (1) (3.81 g, 6.16 mmol) and bromoethane
(0.80 g, 7.34 mmol, 20% excess). The yield of compound 2b was
1.30 g (59%), light yellow oil. Found (%): C, 76.89; H, 5.22;
P, 17.89. C23H20P2. Calculated (%): C, 77.09; H, 5.63; P, 17.29.
All manipulations for the preparation of the starting reagents
and the synthesis and isolation of products were carried out in an
inert atmosphere using standard Schlenk techniques. All solꢀ
vents were distilled over Na/benzophenone immediately before
1
use. H, 13C, and 31P NMR spectra were recorded on a Bruker
3
1H NMR (C6D6), δ: 0.94 (dt, 3 H, CH3, JH,H = 7.34 Hz,
MSLꢀ400 instrument (400 (1H), 100.6 (13C), and 161.975 MHz
3JH,P = 14.51 Hz); 2.13 (m, 2 H, CH2); 7.34 (d, 3JH,H = 7.34 Hz);
(
31P)) for 10—20% solutions in inert solvents (C6D6, CDCl3)
3
3
with Me4Si as the internal standard (1H and 13C) and with 85%
H3PO4 as the external standard (31P).
6.96 (t, 4 H, JH,H = 6.36 Hz); 7.00 (d, 4 H, JH,H = 4.89 Hz);
7.03 (d, 2 H, 3JH,H = 5.87 Hz); 7.07 (d, 4 H, 3JH,H = 7.34 Hz);
3
3
7.23 (d, 2 H, JH,H = 5.38 Hz); 7.31 (t, 1 H, JH,H = 8.31 Hz).
Sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentadienide (1)
was prepared according to a known procedure.13 Bromomethane,
bromoethane, 1ꢀbromoꢀ2ꢀmethylpropane, 1ꢀbromobutane,
2ꢀiodopropane, iodocyclohexane, chlorotrimethylsilane, and
trimethyltin chloride were commercial reagents used without
further purification.
1ꢀAlkylꢀ3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentadienides (2)
(general procedure). An appropriate alkyl halide (1.2 mmol) was
added at –80 °C to a solution of sodium 3,4,5ꢀtriphenylꢀ1,2ꢀ
diphosphacyclopentadienide (1) (1 mmol) in THF (30 mL). The
reaction mixture was stirred at ~20 °C for 3 h. The solvent was
removed and the product was extracted from the residue with
hexane (2×30 mL). The extract was filtered, concentrated, and
dried in vacuo. No further purification of the target product was
required.
31P NMR (C6D6), δ: 209.47 (d, JP,P = 408.88 Hz); 73.08
1
(d, JP,P = 408.88 Hz). 13C NMR (C6D6), δ: 13.98 (d, CH3,
1
2JC,P = 2.89 Hz); 17.87 (dd, CH2, JC,P = 16.13 Hz, JC,P
=
1
2
= 5.79 Hz); 126.37 (s, C(11)); 126.52 (s, C(15)); 126.88 (s, C(7));
127.52 (s, C(6)); 128.03 (s, C(10)); 128.26 (s, C(14)); 128.65 (dd,
C(5), 3JC,P = 11.17 Hz, 4JC,P = 2.48 Hz); 129.23 (d, C(13), 3JC,P
3
= 9.32 Hz); 131.38 (t, C(8), JC,P = 9.10 Hz); 137.34 (d, C(9),
2
3
4JC,P = 5.38 Hz); 138.33 (dd, C(4), JC,P = 10.34 Hz, JC,P
=
= 4.14 Hz); 142.89 (d, C(12), 2JC,P = 19.02 Hz); 150.28 (t, C(2),
1
2
2JC,P = 15.09 Hz); 164.14 (dd, C(3), JC,P = 10.75 Hz, JC,P
=
= 4.55 Hz); 191.90 (dd, C(1), 1JC,P = 56.86 Hz, 2JC,P = 14.27 Hz).
1ꢀ(2ꢀMethylpropyl)ꢀ3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopenꢀ
taꢀ2,4ꢀdiene (2c) was obtained from sodium 3,4,5ꢀtriphenylꢀ1,2ꢀ
diphosphacyclopentadienide (1) (4.12 g, 6.65 mmol) and 1ꢀbroꢀ
moꢀ2ꢀmethylpropane (1.09 g, 7.98 mmol, 20% excess). The yield
of compound 2c was 1.37 g (55%), light yellow oil. Found (%):
1ꢀMethylꢀ3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentaꢀ2,4ꢀdiꢀ
ene (2a) was obtained from sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosꢀ

Reactions of sodium 1,2ꢀdiphospholide with RHal
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 6, June, 2010
1235
C, 77.82; H, 6.04; P, 16.14. C25H24P2. Calculated (%): C, 77.71;
2f was 1.00 g (45%), light yellow powder. Found (%): C, 78.76;
H, 6.27; P, 15.21. C27H26P2. Calculated (%): C, 78.63; H, 6.35;
P, 15.02. 1H NMR (C6D6), δ: 1.4—1.7 (m, 10 H); 2.44 (m, 1 H,
CH); 6.9—7.4 (m, 15 H, Ph). 31P NMR (C6D6), δ: 204.57
(d, 1JP,P = 413.46 Hz); 87.47 (d, 1JP,P = 413.46 Hz). 13C NMR
3
H, 6.26; P, 16.03. 1H NMR (C6D6), δ: 0.84 (d, 6 H, JH,H
=
= 6.85 Hz); 1.48 (m, 1 H, CH); 1.74 (m, 2 H, CH2); 6.70—7.20
(m, 15 H, Ph). 31P NMR (C6D6), δ: 207.47 (d, 1JP,P = 420.73 Hz);
62.78 (d, 1JP,P = 420.73 Hz). 13C NMR (C6D6), δ: 23.54 (d, CH3,
3
3
3JC,P = 7.86 Hz); 23.81 (d, CH3, JC,P = 7.03 Hz); 27.24
(C6D6), δ: 20.64 (s, CH2); 22.14 (d, CH2, JC,P = 6.86 Hz);
2
2
(d, JC,P = 4.96 Hz); 33.57 (d, JC,P = 16.95 Hz); 126.29
22.41 (d, CH2, 2JC,P = 6.94 Hz); 23.17 (d, CH2, 2JC,P = 13.43 Hz);
2
2
(s, C(15)); 126.42 (s, C(7)); 126.45 (s, C(11)); 127.27 (s, C(6));
23.36 (d, CH2, JC,P = 12.97 Hz); 28.78 (d, CH, JC,P =
3
127.92 (s, C(10)); 128.29 (s, C(14)); 128.67 (d, C(5), JC,P
=
= 17.03 Hz); 125.67 (s, C(15)); 125.87 (s, C(7)); 126.38 (s, C(11));
127.67 (s, C(6)); 127.99 (s, C(10)); 128.14 (s, C(14)); 128.41
(d, C(5), 3JC,P = 14.93 Hz); 129.62 (d, C(13), 3JC,P = 9.06 Hz);
131.14 (t, C(8), 3JC,P = 6.89 Hz); 136.78 (d, C(9), 4JC,P = 5.26 Hz);
3
= 16.04 Hz); 129.44 (d, C(13), JC,P = 10.06 Hz); 133.24
(d, C(8), JC,P = 16.95 Hz); 137.46 (d, C(9), JC,P = 6.20 Hz);
138.24 (dd, C(4), JC,P = 10.34 Hz, JC,P = 3.72 Hz); 142.81
(d, C(12), 2JC,P = 19.44 Hz); 149.17 (t, C(2), 2JC,P = 15.51 Hz);
164.56 (dd, C(3), JC,P = 7.24 Hz, JC,P = 3.10 Hz); 188.82
(dd, C(1), 1JC,P = 57.07 Hz, 2JC,P = 14.89 Hz).
3
4
2
3
2
3
139.34 (dd, C(4), JC,P = 13.54 Hz, JC,P = 5.32 Hz); 143.67
(d, C(12), 2JC,P = 19.04 Hz); 150.67 (t, C(2), 2JC,P = 16.43 Hz);
1
2
1
2
166.48 (dd, C(3), JC,P = 8.96 Hz, JC,P = 4.33 Hz); 191.02
(dd, C(1), 1JC,P = 55.24 Hz, 2JC,P = 15.03 Hz).
1ꢀButylꢀ3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentaꢀ2,4ꢀdiene
(2d) was obtained from sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyꢀ
clopentadienide (1) (4.78 g, 7.71 mmol) and 1ꢀbromobutane
(1.26 g, 9.25 mmol, 20% excess). The yield of compound 2d was
1.70 g (59%), light yellow powder. Found (%): C, 77.86; H, 6.14;
P, 16.23. C25H24P2. Calculated (%): C, 77.71; H, 6.26; P, 16.03.
3,4,5ꢀTriphenylꢀ1ꢀtrimethylsilylꢀ1,2ꢀdiphosphacyclopentaꢀ
2,4ꢀdiene (3) was obtained from sodium 3,4,5ꢀtriphenylꢀ1,2ꢀ
diphosphacyclopentadienide (1) (1.93 g, 3.31 mmol) and chloroꢀ
trimethylsilane (0.51 g, 4.67 mmol, 50% excess). The yield of
compound 3 was 0.87 g (65%), yellow oil. Found (%): C, 71.86;
H, 6.19; P, 15.41. C24H24P2Si. Calculated (%): C, 71.62; H, 6.01;
P, 15.39. 1H NMR (C6D6), δ: 0.15 (d, 9 H, Me, 3JH,P = 7.98 Hz);
3
1H NMR (C6D6), δ: 0.59 (t, CH3, 3 H, JH,H = 7.34 Hz); 1.02
(m, 2 H, CH2); 1.36 (m, 2 H, CH2); 2.02 (m, 2 H, CH2); 6.85
3
3
(d, 4 H, JH,P = 3.42 Hz); 6.90 (d, 2 H, JH,P = 7.34 Hz); 6.96
6.14—7.45 (m, 15 H, Ph). 31P NMR (C6D6), δ: 212.26 (d, 1JP,P
=
3
(d, 4 H, JH,P = 6.85 Hz); 6.99 (m, 1 H, 3JH,P = 5.38 Hz); 7.20
= 409.46 Hz); 67.10 (d, 1JP,P = 409.46 Hz). 13C NMR (C6D6), δ:
3
3
2
(d, 2 H, JH,P = 7.34 Hz); 7.29 (d, 2 H, JH,P = 5.87 Hz).
5.35 (d, Me, JC,P = 14.15 Hz); 124.92 (s, C(11)); 126.41
31P NMR (C6D6), δ: 211.73 (d, JP,P = 416.28 Hz); 68.68
(s, C(15)); 126.72 (s, C(7)); 127.33 (s, C(6)); 127.69 (s, C(10));
1
(d, JP,P = 416.28 Hz). 13C NMR (C6D6), δ: 17.54 (s, CH3);
128.31 (s, C(14)); 128.96 (d, C(5), JC,P = 12.83 Hz); 129.45
1
3
23.81 (d, CH2, 3JC,P = 2.03 Hz); 24.19 (d, CH2, 2JC,P = 6.12 Hz);
(d, C(13), JC,P = 9.32 Hz); 134.84 (t, C(8), JC,P = 6.88 Hz);
3
3
1
1
4
2
27.24 (dd, CH2, JC,P = 34.96 Hz, JC,P = 8.23 Hz); 125.99
138.41 (d, C(9), JC,P = 3.89 Hz); 139.74 (dd, C(4), JC,P
= 17.31 Hz, 3JC,P = 4.94 Hz); 147.32 (d, C(12), 2JC,P = 15.04 Hz);
155.03 (t, C(2), JC,P = 15.04 Hz); 169.92 (dd, C(3), JC,P =
= 14.34 Hz, 2JC,P = 4.67 Hz); 191.32 (dd, C(1), 1JC,P = 45.23 Hz,
2JC,P = 14.62 Hz).
=
(s, C(11)); 126.17 (s, C(15)); 126.32 (s, C(7)); 127.45 (s, C(6));
3
2
1
127.86 (s, C(10)); 128.39 (s, C(14)); 128.87 (dd, C(5), JC,P
=
4
3
= 12.56 Hz, JC,P = 2.12 Hz); 129.45 (d, C(13), JC,P = 9.14
Hz); 131.49 (t, C(8), JC,P = 6.96 Hz); 136.89 (d, C(9), 4JC,P
=
3
= 5.14 Hz); 139.67 (dd, C(4), 2JC,P = 12.13 Hz, 3JC,P = 2.98 Hz);
2
2
148.17 (d, C(12), JC,P = 15.89 Hz); 152.98 (t, C(2), JC,P
=
Reactions of sodium 3,4,5ꢀtriphenylꢀ
1,2ꢀdiphosphacyclopentadienide (1) with tin chlorides
= 19.12 Hz); 169.49 (dd, C(3), 1JC,P = 10.17 Hz, 2JC,P = 4.59 Hz);
195.19 (dd, C(1), 1JC,P = 51.17 Hz, 2JC,P = 10.07 Hz).
1ꢀIsopropylꢀ3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentaꢀ2,4ꢀ
diene (2e) was obtained from sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosꢀ
phacyclopentadienide (1) (1.93 g, 3.11 mmol) and 2ꢀiodoproꢀ
pane (0.80 g, 4.67 mmol, 50% excess). The yield of compound
2e was 0.46 g (40%), light yellow powder. Found (%): C, 76.56;
H, 6.12; P, 16.03. C24H22P2. Calculated (%): C, 77.41; H, 5.95;
P, 16.64. 1H NMR (C6D6), δ: 1.18 (dd, CH3, 6 H, 3JH,H = 7.14 Hz,
3JH,P = 15.07 Hz); 2.49 (m, 1 H, CH); 6.90—7.40 (m, 15 H, Ph).
3,4,5ꢀTriphenylꢀ1ꢀtrimethylstannylꢀ1,2ꢀdiphosphacyclopenꢀ
taꢀ2,4ꢀdiene (4). Solid Me3SnCl (1.08 g, 5.4 mmol) was added
at –78 °C to a suspension of sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiꢀ
phosphacyclopentadienide (1) (1.9 g, 5.4 mmol) in toluene
(25 mL). The reaction mixture was stirred at ~20 °C for 2 h. The
solvent was removed and the product was extracted with hexane
(3×25 mL). The extract was filtered, concentrated, and dried
in vacuo. The yield of compound 4 was 1.57 g (59%), a light
yellow oil that crystallizes on storage. Found (%): C, 58.35;
H, 5.41; P, 13.21. C25H27P2Sn. Calculated (%): C, 59.09;
H, 5.36; P, 12.19; Sn, 23.36. 1H NMR (C6D6), δ: –0.005 (s, 9 H,
Me, JSn,H = 53.8 Hz); 6.89 (t, 4 H, Cp, Ph, JH,H = 3.18 Hz);
6.94—7.02 (m, 8 H, Ph); 7.24 (d, 4 H, Co, Ph, 3JH,H = 6.36 Hz).
31P NMR (C6D6), δ: 116.39 (s). 13C NMR (C6D6), δ: 0.37
(s, Me—Sn); 127.30 (Cp, Ph); 127.57 (Cp, Ph); 128.76 (Cm, Ph);
128.86 (Cm, Ph); 130.28 (Co, Ph); 132.20 (Co, Ph); 140.04
(s, Cipso, Ph); 142.92 (t, Cipso, Ph, 2JC,P = 7.03 Hz); 154.65 (t, C(2),
2JC,P = 4.96 Hz); 181.06 (t, C(1), 1JC,P = 21.71 Hz). 119Sn NMR
(CDCl3), δ: 50.8 (t, 1JSn,P = 276 Hz).
1
31P NMR (C6D6), δ: 209.28 (d, JP,P = 410.28 Hz); 94.47
1
(d, JP,P = 410.28 Hz). 13C NMR (C6D6), δ: 14.48 (d, CH3,
2JC,P = 7.02 Hz); 26.18 (dd, CH, 1JC,P = 19.29 Hz, 2JC,P = 4.93 Hz);
126.74 (s, C(11)); 126.77 (s, C(15)); 126.98 (s, C(7)); 127.29
(s, C(6)); 128.19 (s, C(10)); 128.51 (s, C(14)); 128.79 (dd, C(5),
2
3
4
3
3JC,P = 12.71 Hz, JC,P = 1.96 Hz); 129.94 (d, C(13), JC,P
=
3
= 8.92 Hz); 132.84 (t, C(8), JC,P = 8.14 Hz); 136.98 (d, C(9),
4JC,P = 4.84 Hz); 139.83 (dd, C(4), JC,P = 11.83 Hz, JC,P
=
2
3
= 5.03 Hz); 141.27 (d, C(12), 2JC,P = 18.67 Hz); 151.94 (t, C(2),
2JC,P = 17.21 Hz); 167.51 (dd, C(3), JC,P = 9.83 Hz, JC,P
=
1
2
= 4.89 Hz); 197.88 (dd, C(1), 1JC,P = 51.67 Hz, 2JC,P = 12.65 Hz).
1ꢀCyclohexylꢀ3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentaꢀ2,4ꢀ
diene (2f) was obtained from sodium 3,4,5ꢀtriphenylꢀ1,2ꢀdiphosꢀ
phacyclopentadienide (1) (3.33 g, 5.37 mmol) and 1ꢀiodocycloꢀ
hexane (1.69 g, 8.05 mmol, 50% excess). The yield of compound
Dimethylbis(3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentaꢀ2,4ꢀ
dienꢀ1ꢀyl)stannane (6). Solid Me2SnCl2 (1.19 g, 5.4 mmol)
was added at –78 °C to a suspension of sodium 3,4,5ꢀtriphenylꢀ
1,2ꢀdiphosphacyclopentadienide (1) (3.8 g, 10.8 mmol) in toluꢀ

1236
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 6, June, 2010
Milyukov et al.
ene (40 mL). The reaction mixture was stirred at ~20 °C for 2 h.
The solvent was removed and the product was extracted with
hexane (3×25 mL). The extract was filtered, concentrated, and
dried in vacuo to give a light yellow oil (3.8 g) consisting
of 1ꢀ(chlorodimethylstannyl)ꢀ3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphaꢀ
cyclopentaꢀ2,4ꢀdiene (5) and dimethylbis(3,4,5ꢀtriphenylꢀ1,2ꢀ
diphosphacyclopentaꢀ2,4ꢀdienꢀ1ꢀyl)stannane (6) (according to
1H and 31P NMR spectra).
3. S. R. Gilbertson, D. G. Genov, A. L. Rheingold, Org. Lett.,
2000, 2, 2885.
4. T. Faitg, J. Soulié, J. Lallemand, F. Mercier, F. Mathey,
Tetrahedron, 2000, 56, 101.
5. F. Mercier, F. Brebion, R. Dupont, F. Mathey, Tetrahedron:
Asymmetry, 2003, 14, 3137.
6. D. Neibecker, R. Reau, Angew. Chem., 1989, 101, 479 [Anꢀ
gew. Chem., Int. Ed. Engl., 1989, 28, 500].
7. W. A. Herrmann, C. W. Kohlpaintner, R. B. Manetsberger,
J. Mol. Catal. A, 1995, 97, 65.
8. C. Charrier, H. Bonnard, G. Lauzon, F. Mathey, J. Am.
Chem. Soc., 1983, 105, 6871.
9. V. Miluykov, I. Bezkishko, A. Zagidullin, O. Sinyashin,
P. Lönnecke, E. HeyꢀHawkins, Eur. J. Org. Chem., 2009,
1269.
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Chem. Eur. J., 1999, 11, 3143.
11. M. Hofmann, T. Clark, F. W. Heinemann, U. Zenneck,
Eur. J. Inorg. Chem., 2008, 2225.
Compound 5. 1H NMR (C6D6), δ: –0.42 (s, 6 H, Me, 2JSn,H
=
= 52.8 Hz); 6.9—7.3 (m, 15 H, Ph). 31P NMR (C6D6), δ: 108.4
(s, 1JP,Sn = 388.1 Hz).
Compound 6. 1H NMR (C6D6), δ: –0.04 (s, 6 H, Me, 2JSn,H
=
= 58.6 Hz); 6.9—7.3 (m, 15 H, Ph). 31P NMR (C6D6), δ: 112.9
(s, 1JP,Sn = 372 Hz).
Heating of a mixture of compounds 5 and 6 in vacuo at
120 °C for 3 h with simultaneous removal of Me2SnCl2 followed
by recrystallization from hexane at –80 °C gave dimethylꢀ
bis(3,4,5ꢀtriphenylꢀ1,2ꢀdiphosphacyclopentaꢀ2,4ꢀdienꢀ1ꢀyl)ꢀ
stannane (6) (2.61 g, 60%), light yellow powder, m.p. 87 °C
(decomp.). Found (%): C, 63.71; H, 4.24; P, 15.07. C44H36P4Sn.
Calculated (%): C, 65.46; H, 4.49; P, 15.35. 13C NMR (C6D6),
δ: 0.55 (s, Me—Sn); 127.1 (Cp, Ph); 127.5 (Cp, Ph); 128.1
(Cm, Ph); 128.9 (Cm, Ph); 130.8 (Co, Ph); 131.8 (Co, Ph); 141.1
(s, Cipso, Ph); 142.4 (t, Cipso, Ph, 2JC,P = 6.5 Hz); 151.7 (t, C(2),
12. NMR Spectroscopy. An Introduction, Ed. H. Günther, Wiley,
New York, 1984, 478 pp.
13. I. Bezkishko, V. Miluykov, A. Kataev, D. Krivolapov,
I. Litvinov, O. Sinyashin, E. HeyꢀHawkins, J. Organomet.
Chem., 2008, 693, 3318.
1
2JC,P = 4.6 Hz); 184.5 (t, C(1), JC,P = 21.4 Hz). 119Sn NMR
(CDCl3), δ: 54.8 (t, 1JSn,P = 372 Hz).
References
1. F. Mathey, Acc. Chem. Res., 2004, 37, 954.
2. F. Mathey, Chem. Rev., 1988, 88, 429.
Received December 15, 2009;
in revised form April 15, 2010