Chlorophosphaalkenyl- and chloroalkenylstibanes

Article abstract of DOI:10.1016/j.jorganchem.2008.04.012

Mono-, bis- and tris(chlorophosphaalkenyl)stibanes have been obtained from Mes^*P{double bond, long}C(SiMe₃)Li (Mes^* = 2,4,6-tri-tert-butylphenyl) or from the phosphaalkene carbenoid Mes^*P{double bond, long}C(X)L

Full text of DOI:10.1016/j.jorganchem.2008.04.012

Journal of Organometallic Chemistry 693 (2008) 2293–2298
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Chlorophosphaalkenyl- and chloroalkenylstibanes
*
Lise Baiget, Rami El Ayoubi, Henri Ranaivonjatovo, Jean Escudié , Heinz Gornitzka
Hétérochimie Fondamentale et Appliquée, UMR-CNRS 5069, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex 09, France
a r t i c l e i n f o
a b s t r a c t
Mono-, bis- and tris(chlorophosphaalkenyl)stibanes have been obtained from Mes*P@C(SiMe3)Li
(Mes* = 2,4,6-tri-tert-butylphenyl) or from the phosphaalkene carbenoid Mes*P@C(X)Li (X = Cl) and
SbF3, Mes*Sb(OMes*)F or Mes*SbF2. Bis[chloroalkenyl]stibanes [R2C@C(Cl)]2SbCl (R2C = fluorenylidene
and 2,7-di-tert-butylfluorenylidene) have also been obtained from R2C@C(Cl)Li and SbCl3.
Ó 2008 Elsevier B.V. All rights reserved.
Article history:
Received 10 March 2008
Received in revised form 7 April 2008
Accepted 7 April 2008
Available online 13 April 2008
Keywords:
Antimony
Chloroalkenylstibane
Chlorophosphaalkenylstibane
Nucleophilic substitution
1. Introduction
2. Results and discussion
A great number of phosphorus derivatives have been synthe-
sized. By contrast, going down group 15, arsenic, antimony and bis-
muth compounds are less abundant. One of the reasons could be
the lack of As, Sb or Bi NMR spectroscopy for characterization of
compounds, whereas 31P NMR spectroscopy is extremely useful.
Furthermore, the element–carbon bonds are less strong for the
heavier group 15 congeners.
2.1. Phosphaalkenylstibanes
Depending on the substituents on the phosphaalkenyl group
and on the antimony atom, it is possible to direct the reaction to-
wards the first mono-, bis- or tris(phosphaalkenyl)stibanes.
2.1.1. Tris(phosphaalkenyl)stibanes
We planned to prepare novel types of stibanes RnSbX3ꢀn
(R = chloroalkenyl ˜C@C(Cl) and chlorophosphaalkenyl –P@C(Cl)
groups). The presence of the C@C and C@P unsaturations and of
halogen atoms allowing further substitution or functionalization
should increase their synthetic utilities. As previously observed
from similar models, a chlorine atom on the sp2 carbon atom can
be easily replaced using a lithium compound at low temperature
to afford E@C(Li)–E0 derivatives (E = R2C, E0 = R2Ge [1a], R2Sn [1b],
RSb [1c]; E = P, E0 = R2Si [1d,1e,1f], RP [1g], R2Ge [1h,1i]). Depend-
ing on E0, stable lithium, vic-halolithium or heteroallenic com-
pounds can be obtained.
Phosphaalkenes –P@C— need great steric hindrance around the
phosphorus–carbon double bond to be stabilized as monomers (for
reviews, see Ref. [2]); for this goal the very bulky 2,4,6-tri-tert-
butylphenyl group (Mes* called supermesityl) has often been used
on the phosphorus atom to prevent dimerization. Owing to this
group, some phosphaalkenyl compounds of the type
Mes*P@C(X)–ERR0 (X = Cl, Br; E = heavier element of group 15 such
as P [1g,3], or As [4]) have previously been stabilized and isolated.
The best route to substitute E by the chlorophosphaalkenyl group
Mes*P@C(Cl) is to use the kinetically stabilized carbenoid
Mes*P@C(Cl)Li [5] 1 obtained from Mes*P@CCl2 through a halogen
metal exchange.
We present in this paper the synthesis of chlorophosphaalke-
nylstibanes [Mes*P@C(Cl)]3ꢀnSbRn (R = Mes*, Cl; n = 0,1), sily-
Reaction of 1 with SbF3 at low temperature led exclusively to
the new tris(phosphaalkenyl)stibane 2. Surprisingly, even with a
large excess of SbF3, only the trisubstituted antimony derivative
2 was obtained (Scheme 1).
lphosphaalkenylstibane
[Mes*P@C(SiMe3)]Sb(F)Mes*
and
chloroalkenylstibanes [˜C@C(Cl)]2SbCl starting from the commer-
cially available SbX3 (X = F, Cl).
Compound 2 was isolated in the form of an air-stable powder.
The phosphaalkenyl groups display a single set of signals in 1H
and 13C NMR spectroscopy. A singlet at d = 299.3 ppm was ob-
served in the 31P NMR spectrum. This more deshielded signal, in
comparison with that of the starting dichlorophosphaalkene,
is expected upon substitution of a chlorine atom by a more
* Corresponding author.
E-mail address: escudie@chimie.ups-tlse.fr (J. Escudié).
0022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.04.012

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L. Baiget et al. / Journal of Organometallic Chemistry 693 (2008) 2293–2298
Cl
Sb
Cl
Mes*
Mes*
Mes*
Cl
Cl
Mes*
Cl
Li
Mes*
P
C
C
P
P
n-BuLi
SbF3
P
C
P
C
C
Cl
2
1
Mes* =
Scheme 1. Synthesis of tris(phosphaalkenyl)stibane 2.
electropositive element [6]. According to these data, the three
phosphaalkenyl groups adopt the same configuration, probably
with the Mes* group and the Sb atom in a trans disposition since
it has been demonstrated that the lithium halogen exchange pref-
erentially takes place at the E-chlorine of Mes*P@CCl2 and that
phosphacarbenoid 1 is configurationally stable [5]. Unfortunately,
a single crystal could not be obtained for the structural determina-
tion by X-ray to prove this stereochemistry.
SbF3
n-BuLi
THF
Mes*Br
Mes*Li
Mes*SbF2 + Mes*2SbF
4
5
Scheme 3. Synthesis of fluorostibanes 4 and 5.
(Scheme 4). Interestingly, the same bis(phosphaalkenyl)stibane 6
could be obtained starting from alkoxyfluorostibane 7, showing
that both a fluorine or an alkoxy group, even extremely bulky, on
antimony could be replaced by the phosphaalkenyl group.
Compound 6 presents an interesting structure for complexation
of transition metals by the two phosphorus atoms, (for complexa-
tion of a transition metal by two Mes*P@C units, see Ref. [7]) and
might be a potential precursor of a three-membered ring heterocy-
cle of antimony by coupling of the two C(Cl) atoms.
2.1.2. Bis(phosphaalkenyl)stibanes
A bis(phosphaalkenyl)stibane (3) can be synthesized by using
antimony trichloride, instead of antimony trifluoride, and two
equivalents of carbenoid 1 (Scheme 2). A very small amount of
tris(phosphaalkenyl)derivative 2 was also obtained. With a large
excess of SbCl3, a product with a 31P chemical shift at 297.5 ppm
was also formed in about 10% yield. As a further addition of carb-
enoid led to the disappearance of this product and an increase in
amount of the bis- and trisubstituted derivatives, it can be tenta-
2.1.3. Mono(phosphaalkenyl)stibane
In order to obtain mono-substitution of the antimony atom by a
phosphaalkenyl group, it was necessary to use the more hindered
phosphaalkenyllithium compound 8 [5c], with a trimethylsilyl
group instead of a chlorine atom, obtained from 9 [8]. Addition
to the difluorostibane 4 led exclusively to 10 (Scheme 5).
The greater bulkiness of the phosphaalkenyllithium 8 prevents
the second fluorine atom in starting compound 4 from being re-
placed. Although lithium derivative 8 has been reported to isomer-
ize rapidly [5c], the 31P NMR analysis of the crude reaction mixture
showed one isomer of fluoro(phosphaalkenyl)stibane 10 to pre-
dominate, probably the E-isomer since a similar result was noticed
by Bickelhaupt et al. in the reaction of 8 with magnesium bromide
or zinc chloride [5c].
tively
assigned
to
the
dichloro(phosphaalkenyl)stibane
Mes*P@C(Cl)–SbCl2. Few single crystals of 3 could be obtained
and an X-ray analysis unambiguously proved its structure but,
due to the poor quality of the crystal, a correct refinement was
not possible. Compound 3 was also characterized by 31P NMR spec-
troscopy with a unique signal at 300.3 ppm, very close to the signal
observed for the trisubstituted derivative 2. Like derivative 2, 3 is
probably obtained as the E,E-isomer.
Another class of antimony derivatives, with an aryl group in-
stead of a halogen on the antimony atom, could be obtained start-
ing from Mes*SbF2 (the latter was obtained from the reaction of
Mes*Li with SbF3); whatever the experimental conditions (reac-
tions at ꢀ78 °C, ꢀ30 °C or room temperature, addition of Mes*Li
to SbF3 or reverse addition and use of various solvent such as tol-
uene, Et2O or THF), a mixture of Mes*SbF2 and Mes2* SbF was formed,
but both compounds could be obtained in a pure state by fractional
crystallization (Scheme 3). Thus, despite the high steric hindrance of
the supermesityl group, two units can be easily put on antimony.
Compound 4 was also prepared by a disproportionation reaction
by heating equimolar amounts of Mes*2SbF 5 and SbF3 under reflux
in toluene.
2.2. Alkenylstibanes
Some mono-, bis- or tris(alkenyl)-substituted derivatives of
antimony [˜C@C(R)]nSbR03ꢀn have previously been prepared [9];
however most of them are substituted on the carbon atom bonded
to antimony by hydrogen, alkyl or aryl groups which do not allow
a further functionalization.
In the reaction of carbenoid 1 with Mes*SbF2, the exclusive for-
mation of the bis(phosphaalkenyl)stibane 6 was observed in the
form of only one isomer, probably the E, E-isomer for the reasons
previously reported. As in the reaction of 1 with SbF3, all the fluo-
rine atoms are replaced, even when a large excess of 4 was used
Mes*SbF2
4
Mes*
Mes*
Cl
Mes*
Cl
Li
P
P
C
P
C
Sb Mes*
C
1
Cl
Mes*Sb(F)OMes*
7
6
Mes*
Cl
P
P
C
SbCl3
Mes*SbF2
Mes*
Cl
Li
THF/-78 °C
Sb
Cl
P
C
4
C
Mes*OH
Mes*OLi
Cl
n-BuLi
THF/ 0 °C
Mes*
3
Scheme 2. Synthesis of bis(phosphaalkenyl)stibane 3.
Scheme 4. Synthesis of bis(phosphaalkenyl)stibane 6.

L. Baiget et al. / Journal of Organometallic Chemistry 693 (2008) 2293–2298
2295
Mes*SbF2
Mes*
SiMe3
Mes*
Br
4
n-BuLi
Mes*P C(SiMe3)Li
P
C
P
C
THF/-90 °C
Sb
F
SiMe3
10
8
9
Mes*
Scheme 5. Synthesis of mono(phosphaalkenyl)stibane 10.
In order to increase the synthetic utility of alkenylstibanes, we
planned to substitute, as in the case of phosphaalkenylstibanes,
the sp2 carbon atom bonded to antimony by a chlorine atom.
Substituted fulvenyl groups R2C@C(Cl), with R2C being a fluoreny-
lidene or a 2,7-di-tert-butylfluorenylidene appeared promising:
such groups, due to the bulkiness of the fluorenylidene moiety (3
fused rings), should display good stabilizing properties; moreover,
compounds substituted by fluorenyl groups generally easily crys-
tallize due in particular to their special planar geometry.
Like phosphaalkenyl derivatives, the best way to substitute
antimony by the chloroalkenyl group R2C@C(Cl) is to use the kinet-
ically stabilized alkene carbenoid R2C@C(Cl)Li 11a,b obtained from
R2C@CCl2 12a,b through a halogen/lithium exchange.
The starting new 9-(dichloromethylene)-2,7-di-tert-butylfluo-
rene 12b was prepared from 2,7-di-tert-butylfluorenone [10],
according to the procedure described by Normant to synthesize
12a [11] (Scheme 6). Compound 12b was characterized by signals
at 121.0 (C@CCl2) and 150.3 ppm (CCl2) in its 13C NMR spectrum,
and by an X-ray analysis which displays standard bond lengths
and angles (Fig. 1) (Table 1).
Fig. 1. Molecular structure (50% probability thermal ellipsoids) of 12b with atom
labeling scheme. Only one molecule of the two independent ones present in the
asymmetric unit is depicted. Hydrogen atoms have been omitted for clarity. Sele-
cted bond lengths (Å) and angles (°): C1–C2, 1.340(4); C1–Cl1, 1.723(3); C1–Cl2,
1.724(3); C2–C3, 1.491(3); C2–C14, 1.494(4); Cl1–C1–Cl2, 110.64(14); Cl1–C1–C2,
124.5(2); Cl2–C1–C2, 124.9(2); C1–C2–C3, 127.1(2); C1–C2–C14, 127.0(2); C3–C2–
C14, 105.9(2).
Reaction of alkenylidene carbenoids 11a,b, obtained from 12a,b
and n-BuLi at low temperature, with SbCl3 led exclusively to the
bis(alkenyl)stibanes 13a,b (Scheme 7).
Table 1
Crystal data for compounds 12b and 13a
12b
13a
Derivatives 13a,b have been characterized by mass spectrome-
try, 1H and 13C NMR spectroscopies which display as expected that
all the proton and carbon atoms of a same fluorenylidene group are
inequivalent and 13a by an X-ray structural study (Fig. 2) (Table 1).
C–Cl (1.750(6) and 1.755(7) Å), Sb–C (2.169(6) and 2.187(6) Å) and
Sb–Cl (2.356(1) Å) bond lengths are close to the standard values:
C–Cl (1.77 Å), Sb–C (2.13-2.20 Å) [12], Sb–Cl (2.36 Å) [13]. The
Cl1C1SbCl3 and Cl3SbC15Cl2 torsion angles are quite different, show-
ing a non-symmetrical molecule (see Fig. 2).
The formation of disubstitution derivatives 13 with alkenyllith-
ium 11 must be compared to the formation of a mixture of bi- and
trisubstitution compounds 3 and 2 with phosphaalkenyllithium 1
and SbCl3. Even with an excess of SbCl3, the compound with three
R2C@C(Cl) groups was not formed. The decreasing in the substitut-
ing ability of R2C@C(Cl)Li compared to Mes*P@C(Cl)Li can be prob-
ably explained by a lower nucleophilicity of the more stabilized
anion [R2C@CCl]ꢀ. This lower substituting ability of alkenyllithium
11 was also observed in the reaction of 11a with Mes*SbF2, giving
exclusively the mono(alkenyl)stibane 14a (Scheme 8) [1c] whereas
1 led to the bis(phosphaalkenyl)stibane 6 (Scheme 4).
Empirical formula
Formula weight
Temperature (K)
Crystal system
Space group
a (Å)
b (Å)
c (Å)
C
22H24Cl2
C28H16Cl3Sb + CH2Cl2
665.43
193(2)
Orthorhombic
Pna21
20.557(2)
5.577(1)
359.31
173(2)
Monoclinic
P21/c
11.872(1)
11.253(1)
28.538(3)
91.643(2)
3811.0 (6)
8
0.341
21834
7801
0.0490
Semi-empirical
0.8193
7801
0
445
0.982
0.0486
0.1106
0.0993
0.1330
0.329 and
ꢀ0.268
22.146(2)
b
Volume (Å3)
2539.0(5)
4
1.631
12414
4547
0.0517
Semi-empirical
0.5557
4547
1
317
1.012
0.0422
0.0838
0.0589
0.0893
0.735 and ꢀ0.599
Z
Absorption coefficient (mmꢀ1
Reflections collected
Independent reflections
Rint
)
Absorption correction
Minimum/maximum transmission
Data
Restraints
Parameters
Goodness-of-fit on F2
Final R indices [I > 2
wR2
R indices (all data) R1
wR2
r
(I)] R1
Largest difference in peak and hole
(e Åꢀ3
)
Y
Y
7
6
8
5
10
Ph3 P
CCl4
9
13
12
O
CCl2
SbCl3
11
1
R2C=C Cl
Li
R
2C=C Cl
Cl
R2C=C Sb C=CR2
Cl Cl Cl
4
-78 °C
(Y = H, 12a; t-Bu, 12b)
3
2
Y
12a,b
11a,b
13a,b
Y
Scheme 6. Synthesis of fulvenes 12.
Scheme 7. Synthesis of bis(alkenyl)stibanes 13.

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L. Baiget et al. / Journal of Organometallic Chemistry 693 (2008) 2293–2298
of n-BuLi. The solution turned brown and was stirred at this tem-
perature for 30 min. The lithium compound Mes*P@C(Cl)Li was
then added to an excess of SbF3 (0.82 g, 4.58 mmol) in THF
(20 mL) cooled at ꢀ78 °C. The reaction mixture was stirred for
20 min and warmed up to room temperature. Solvents were re-
moved in vacuo and the residue dissolved into pentane (20 mL).
After removal of the lithium salts and excess of SbF3 by filtration,
the resulting solution was dried in vacuo to afford 2 (0.71 g, 86%)
as a colorless powder (mp 215–217 °C).
1H NMR (200.13 MHz): d 1.32 (s, 27H, p-t-Bu), 1.48 (s, 54H, o-t-
Bu), 7.39 (broad s, 6H, arom H).13C NMR (50.32 MHz): d 31.4 and
33.1 (o- and p-C(CH3)3), 35.1 (p-C(CH3)3), 37.9 (o-C(CH3)3), 122.0
1
(m-C), 136.2 (d, JCP = 71.3 Hz, ipso-C), 150.6 (p-C), 153.4 (o-C),
Fig. 2. Molecular structure (50% probability thermal ellipsoids) of 13a with atom
labeling scheme. Hydrogen atoms and a solvent molecule have been omitted for
clarity. Selected bond lengths (Å), angles (°) and torsion angles (°): C1–C2, 1.348(9);
C1–Cl1, 1.755(7); Sb–C1, 2.169(6); Sb–Cl3, 2.3558(14); Sb–C15, 2.187(6); C15–C16,
1.331(9); C15–Cl2, 1.750(6); Cl2–C15–Sb, 115.8(3); Cl2–C15–C16, 119.3(5); C1–Sb–
C15, 94.7(3); C1–Sb–Cl3, 93.3(2); C2–C1–Cl1, 120.7(5); C2–C1–Sb, 128.6(5); Cl1–
C1–Sb, 110.2(3); Cl3–Sb–C15, 96.9(2); Cl2–C15–Sb–Cl3, 9.0; Cl3–Sb–C1–Cl1, 51.9.
170.5 (dt, JCP = 96.3 Hz, JCP = 15.0 Hz, C(Cl)@P).31P NMR: d 299.3.
MS (CI/NH3, m/z, %): 1127 (M+N2H7, 20), 1093 (M+1, 40), 1092
(M, 90), 769 (MꢀMes*P@C(Cl), 100). Anal. Calc. for C57H87Cl3P3Sb:
C, 62.62; H, 8.02. Found: C, 62.87; H, 7.89%.
1
3
4.2. Synthesis of [Mes*P@C(Cl)]2SbCl 3
The experimental process was the same as that for 2, starting
from 1.03 g (2.85 mmol) of Mes*P@CCl2, 1.78 mL (2.85 mmol) of
n-BuLi and 0.21 g, (0.95 mmol) of SbCl3 in THF. The 31P NMR
Li
R2C
C
11a
Cl
Mes*Sb C=CR2
Cl
Mes*SbF2
analysis showed the formation of 3,
2
and possibly
Mes*P@C(Cl)ASbCl2(d31P: 297.5 ppm) in the ratio 85/5/10. Due to
similar solubility in various solvents, the complete purification of
3 was not possible, but crystallization from pentane afforded 3
(0.63 g, 55%) in about 95% purity, mixed with very small amounts
of tris(phosphaalkenyl)stibane 2.
F
3
14a
Scheme 8. Synthesis of monoalkenylstibane 14a.
1H NMR (200.13 MHz): d 1.29 (s, 18H, p-t-Bu), 1.36 (s, 36H, o-t-
Bu), 7.34 (broad s, 4H, arom H), 31P NMR: d 300.3, MS (EI, 70 eV,
m/z, %): 804 (M, 2), 769 (MꢀCl, 2), 573 (MꢀArꢀMe, 18), 57 (t-Bu,
100).
3. Conclusions
Various chlorophosphaalkenyl- and chloroalkenylstibanes have
been obtained. It seems that the reaction rate increases from
mono- to di- or trisubstitution of antimony by chlorophosphaalke-
nyl or chloroalkenyl groups. Indeed, the monosubstituted chloro-
phosphaalkenyl derivative 10 can only be obtained when the
steric hindrance is large enough to prevent disubstitution.
These potentially functional chlorophosphaalkenyl- and chloro-
alkenylstibanes should be interesting building blocks in antimony
chemistry. Their use as ligands with transition metals, as precur-
sors of stibaallenes –Sb@C@X (X = C, P) by dehalogenation, and of
three-membered rings of antimony are under active investigation.
4.3. Synthesis of Mes*SbF2
4
A solution of n-BuLi (20.20 mL, 32.32 mmol) was added drop-
wise to
solution of Mes*Br (10.00 g, 30.76 mmol) in THF
a
(100 mL), cooled to ꢀ80 °C. The solution was stirred at this temper-
ature for 3 h. The lithium compound Mes*Li was then slowly added
to a solution of SbF3 (8.25 g, 46.10 mmol) in THF (50 mL) cooled to
ꢀ80 °C. The reaction mixture was stirred for 10 min and warmed
up to room temperature. A 19F NMR analysis showed the presence
of the two compounds Mes*SbF2 and Mes*2SbF in the ratio 50/50.
After removal of solvents, 100 mL of pentane were added to the res-
idue, lithium salts and excess of SbF3 were removed by filtration.
Recrystallization from pentane afforded first Mes*SbF2 4 (2.58 g,
21%) as a white powder (mp 84 °C) and then Mes*2SbF 5 (3.25 g,
35%, mp 146 °C).
4. Experimental
All experiments were carried out in flame-dried glassware un-
der a nitrogen atmosphere using high-vacuum-line techniques.
Solvents were dried and freshly distilled from sodium benzophe-
none ketyl and carefully deoxygenated on the vacuum line by sev-
eral ‘‘freeze-pump-thaw” cycles. NMR spectra were recorded (with
CDCl3 as solvent) on the following spectrometers: 1H, Bruker
AC200 (200.13 MHz), Avance 300 (300.13 MHz); 13C, Bruker
AC200 (50.32 MHz), and Avance 300 (75.47 MHz) (reference
TMS); 19F, Bruker AC200 (188.30 MHz) (reference CF3COOH); 31P,
Bruker AC200 (80.15 MHz) (reference H3PO4). Melting points were
determined on a Wild Leitz-Biomed apparatus. Mass spectra were
obtained on a Hewlett–Packard 5989A spectrometer by EI at 70 eV
and on a Nermag R10-10 spectrometer by CI. Carbon atoms of the
fluorenylidene group are labeled as indicated in Scheme 6. SbF3,
Me3SiCl, 2,4,6-tri-tert-butylphenol, n-BuLi (1.6 M in hexane) and
Compound 4: 1H NMR (300.13 MHz): d 1.29 (s, 9H, p-t-Bu), 1.50
(t, JHF = 1.0 Hz, 18H, o-t-Bu), 7.43 (s, 2H, arom H); 13C NMR
(75.47 MHz):
d 31.20 (p-C(CH3)3), 34.02 (t, JCF = 2.2 Hz, o-
C(CH3)3), 39.59 (p-C(CH3)3), 40.07 (o-C(CH3)3), 124.45 (m-C),
2
151.51 (p-C), 154.30 (t, JCF = 9.0 Hz, ipso-C), 158.53 (o-C); 19F
NMR: d ꢀ50.9, MS (EI, 70 eV, m/z, %): 404 (M, 1), 385 (MꢀF, 1),
365 (Mꢀ2Fꢀ1, 1), 349 (Mꢀ2FꢀMeꢀ2, 3), 245 (MꢀSbF2, 15), 57
(t-Bu, 100). Anal. Calc. For C18H29F2Sb: C, 53.36; H, 7.21; Found:
C, 53.47; H, 7.33%.
Compound 5: 1H NMR (300.13 MHz): d 1.17 (d, JHF = 0.7 Hz,
36H, o-t-Bu), 1.27 (s, 18H, p-t-Bu), 7.33 (s, 4H, arom H); 13C NMR
5
tert-BuLi (1.5 M in pentane) were purchased from Acros.
¯
(75.47 MHz):
d
31.37 (p-C(CH3)3), 33.85 (d, JCF = 2.5 Hz, o-
C(CH3)3), 34.5 (p-C(CH3)3), 39.62 (o-C(CH3)3), 123.81 (m-C),
2
4.1. Synthesis of [Mes*P@C(Cl)]3Sb 2
147.66 (d, JCF = 11.6 Hz, ipso-C), 149.61 and 158.4 (o- and p-C);
19F NMR: d ꢀ99.4; MS (EI, 70 eV, m/z, %): 611 (MꢀF, 1), 385
(MꢀMes*, 15), 365 (Mes*Sbꢀ1, 18), 57 (t-Bu, 100). Anal. Calc. for
To a colorless solution of Mes*P@CCl2 (0.82 g, 2.29 mmol) in
THF (20 mL) were added dropwise, at ꢀ78 °C, 1.5 mL (2.40 mmol)
C36H56FSb: C, 68.68; H, 8.97. Found: C, 68.81; H, 9.05%.

L. Baiget et al. / Journal of Organometallic Chemistry 693 (2008) 2293–2298
2297
4.4. Synthesis of Mes*SbF2 from Mes2* SbF
to remove lithium salts. Recrystallization from pentane afforded 10
(1.23 g, 69%) as an orange powder (mp 115–117 °C).
Mes*SbF2 can be obtained quantitatively according to a dismu-
tation reaction of 4.0 g (6.35 mmol) of Mes*2SbF and 1.13 g
(6.35 mmol) of SbF3 by reflux in toluene for 2 h.
1H NMR (200.13 MHz): d ꢀ0.26 (s, 9H, SiMe3), 1.28 and 1.29 (2s,
2 ꢁ 9H, p-t-Bu Mes*Sb and Mes*P), 1.39 (s, 18H, o-t-Bu Mes*Sb),
1.53 (d, 18H, 4JPH = 1.2 Hz, o-t-Bu Mes*P), 7.27 (d, 2H, 4JPH = 1.5 Hz,
arom H Mes*P), 7.41 (s, 2H, arom H Mes*Sb); 13C NMR (50.32 MHz):
3
4.5. Synthesis of Mes*Sb[C(Cl)@PMes*]2
6
d 0.7 (d, JCP = 37.9 Hz, SiMe3), 31.3, 33.6, 33.8 and 34.3 (o- and p-
C(CH3)3 Mes*Sb and Mes*P), 34.3 and 34.5 (p-C(CH3)3 Mes*Sb and
3
Mes*P), 38.3 (d, JCP = 7.4 Hz, o-C(CH3)3 Mes*P), 38.7 (o-C(CH3)3
1.6 mL (2.56 mmol) of n-BuLi were added dropwise to a solu-
tion of Mes*PCCl2 (0.88 g, 2.45 mmol) in THF (20 mL), cooled to
ꢀ78 °C. After stirring for 30 min, the solution of Mes*PC(Cl)Li was
cannulated to a solution of Mes*SbF2 (1.00 g, 2.45 mmol) in THF
(25 mL) at ꢀ78 °C. The reaction mixture was stirred for 20 min
and then warmed up to room temperature. Solvents were removed
in vacuo and 15 mL of pentane were added. After removal of salts
by filtration, recrystallization afforded 6 (1.02 g, 82%) as a white
powder in 90% purity.
Mes*Sb), 121.6 and 121.8 (m-C Mes*Sb and Mes*P), 149.8, 150.1,
152.3 (d, J = 1.8 Hz) and 153.5 (d, J = 3.7 Hz) (o- and p-C, ipso-C
1
2
Mes*), 205.6 (dd, JCP = 106.3 Hz, JCF = 9.0 Hz, P=C); 19F NMR: d
ꢀ98.5 (d, JPF = 27.2 Hz); 31P NMR: d 392.5 (d, JPF = 27.2 Hz), MS
(EI, 70 eV, m/z, %): 746 (M, 1), 689 (Mꢀt-Bu, 5), 669 (Mꢀt-BuꢀFꢀ1,
5), 598 (Mꢀ2t-BuꢀFꢀMe, 3), 501 (MꢀMes*, 10), 445 (MꢀMes*ꢀt-
Bu+1, 25), 365 (Mes*Sbꢀ1, 24), 57 (t-Bu, 100); Anal. Calc. for
C40H67FPSbSi: C, 64.25; H, 9.03. Found: C, 64.47; H, 9.21%.
3
3
The same product 6 was obtained (0.43 g, 93%) when the lith-
ium compound Mes*PC(Cl)Li (0.92 mmol) was added to a solution
of Mes*Sb(OMes*)F (0.60 g, 0.92 mmol) under the same conditions.
1H NMR (200.13 MHz): d 1.39, 1.40, 1.54 and 1.70 (4s, 81H, o-
and p-t-Bu Mes*Sb and Mes*P), 7.46 (s, 2H, arom H Mes*Sb), 7.53
4.8. Synthesis of 9-(dichloromethylene)-2,7-di-tert-butylfluorene 12b
81.60 g (0.31 mol) of triphenylphosphine were added to a solu-
tion de 2,7-di-tert-butylfluorenone [10] (14.00 g, 48.0 mmol) in
250 mL of THF. The reaction mixture was heated at reflux and
190 mL (1.85 mol) of carbon tetrachloride were added dropwise
for 5 h. The solution became dark brown; it was heated for one
hour at 65 °C after completion of the addition. After cooling to
room temperature, the reaction mixture was hydrolyzed, extracted
with Et2O and the organic layer was washed with saturated solu-
tions of NaHCO3 and NaCl then dried over Na2SO4. The solvents
were removed under reduced pressure and the resulting brown so-
lid was washed three times with pentane. A recrystallization from
pentane led to 12.00 g (85%) of light yellow needles of C,C-dichlo-
rofulvene 12b (mp 140 °C).
4
(d, JPH = 1.2 Hz, 4H, arom H Mes*P); 13C NMR (50.32 MHz): d
29.8–33.2 (o- and p-C(CH3)3 Mes*P and Mes*Sb), 34.1, 35.1, 38.0
and 38.8 (o- and p-C(CH3)3 Mes*P and Mes*Sb), 121.9 and 122.6
(m-C Mes*P and Mes*Sb), 135.0 (ipso-C Mes*Sb), 137.3 (d,
1JCP = 74.9 Hz, ipso-C Mes*P), 150.3, 150.6 and 153.4 (o- and p-C
1
3
Mes*P and Mes*Sb), 174.6 (dd, JCP = 112.9 Hz, JCP = 12.2 Hz,
C(Cl)@P); 31P NMR: d 295.3.
4.6. Synthesis of Mes*Sb(OMes*)F 7
1.3 mL (2.08 mmol) of n-BuLi were added dropwise at 0 °C to a
yellow solution of 2,4,6-tri-tert-butylphenol (0.52 g, 1.97 mmol) in
THF (15 mL). The solution turned colorless, was stirred for 10 min
and was allowed to warm to room temperature. It was then added
dropwise to a solution of Mes*SbF2 (0.80 g, 1.97 mmol) in THF
(15 mL) cooled to ꢀ78 °C. The reaction mixture was stirred for
20 min and warmed up to room temperature. After removal of sol-
vents, 20 mL of pentane were added and the lithium salts were re-
moved by filtration. The residue was recrystallized from pentane to
afford 7 (0.70 g, 55%) as a white powder (mp 135–137 °C).
1H NMR (300.13 MHz):
d
1.48 (s, 18H, t-Bu), 7.42 (dd,
4
3JHH = 8.0 Hz, JHH = 1.7 Hz, 2H,
H
on C3 and C6), 7.58 (d,
3JHH = 8.0 Hz, 2H, H on C4 and C5), 8.38 (d, JHH = 1.7 Hz, 2H, H on
C1 and C8); 13C NMR (75.47 MHz): d 31.5 (CMe3), 35.0 (CMe3),
118.9, 122.9 and 126.3 (arom CH of CR2), 121.0 (C@CCl2), 134.8,
136.8 and 137.8 (arom C of CR2), 150.3 (CCl2)MS (EI, 70 eV, m/z,
%): 358 (M, 47) 343 (MꢀMe, 100), 57 (t-Bu, 20); Anal. Calc. for
4
C
22H24Cl2: C, 73.54; H, 6.73. Found: C, 73.62; H, 6.85%.
1H NMR (200.13 MHz): d 1.15 (s, 18H, o-t-Bu OMes*), 1.22 and
1.33 (2s, 2 ꢁ 9H, p-t-Bu OMes* andp-t-Bu Mes*), 1.51 (s, 18H, o-t-
Bu Mes*), 7.10 (s, 2H, arom H OMes*), 7.43 (s, 2H, arom H Mes*);
13C NMR (50.32 MHz): d 31.3 and 31.7 (p-C(CH3)3 OMes* and
SbMes*), 32.9 and 34.0 (o-C(CH3)3 OMes* and SbMes*), 35.5 and
39.9 (o- and p-C(CH3)3 OMes* and SbMes*), 123.0 and 124.1 (m-C
OMes* and SbMes*), 141.4, 151.1 and 159.0 (o- and p-C, ipso-C
OMes*), 153.3 (d, JCF = 9.2 Hz, ipso-C SbMes*); 19F NMR: d ꢀ61.6.
MS (EI, 70 eV, m/z, %): 646 (M, 1), 627 (MꢀF, 3), 626 (MꢀFꢀ1, 3),
385 (MꢀOMes*, 40), 365 (Mes*Sbꢀ1, 70), 57 (t-Bu, 100); Anal. Calc.
for C36H58FOSb: C, 66.77; H, 9.03. Found: C, 66.59; H, 8.92%.
4.9. Synthesis of [R2C@C(Cl)]2SbCl 13a
A solution of n-BuLi (3.9 mL, 6.37 mmol) was added dropwise to
a solution of 9-dichloromethylenefluorene 12a (1.50 g, 6.07 mmol)
in THF (15 mL) cooled to ꢀ78 °C. The solution turned purple and,
after stirring for 15 min, was added dropwise to a solution of
SbF3 (0.69 g, 3.02 mmol) in THF at ꢀ78 °C. The temperature was
maintained for 10 min and the mixture was then slowly warmed
to room temperature. Solvents were removed in vacuo, the residue
was extracted with a solution of pentane/dichloromethane (50/50,
2 ꢁ 30 mL), and the insoluble precipitate (LiCl) was filtered out. Re-
moval of the solvent in vacuo followed by recrystallization from
CH2Cl2 yielded 13a (1.07 g, 61%) as yellow crystals (mp 196 °C).
4.7. Synthesis of Mes*Sb(F)–C(SiMe3)@PMes* 10
1H NMR (300.13 MHz): d 6.98 (t, JHH = 7.5 Hz, 2H), 7.22–7.35
3
(m, 6H), 7.60–7.66 (m, 6H), 8.56 (d, JHH = 7.5 Hz, 2H); 13C NMR
3
A solution of n-BuLi (1.5 mL, 2.40 mmol) was added dropwise to
a
solution of Mes*P@C(Br)SiMe3 (1.04 g, 2.26 mmol) in THF
(75.47 MHz): d 120.09 and 120.53 (C4C5), 123.44, 127.07, 127.79,
127.98, 129.37 and 129.89 (CH of CR2), 137.84, 137.87, 140.71,
140.91, 143.49 and 148.23 (C10ꢀ13 and C@C); MS (EI, 70 eV, m/z,
%): 544 (MꢀClꢀ1, 1), 509 (Mꢀ2Clꢀ1, 1), 471 (Mꢀ3Clꢀ2, 1), 422
(MꢀSbCl, 1), 404 (Mꢀ(C@CR2), 15), 352 (MꢀSbCl3, 40), 246
(R2C@CCl2, 30), 176 (R2C@C, 100); Anal. Calc. for C28H16Cl3Sb: C,
57.93; H, 2.78. Found: C, 57.88; H, 2.63% (the solvent molecule
(CH2Cl2) observed by X-ray in the unit cell was removed in vacuo).
(25 mL), cooled to ꢀ90 °C. The reaction mixture was stirred for
30 min and was then allowed to warm to room temperature. The
lithium compound Mes*P@C(SiMe3)Li 8 was then added slowly to
a solution of Mes*SbF2 (0.96 g, 2.37 mmol) in THF (25 mL) cooled
to ꢀ78 °C. The solution was stirred for 10 min and warmed up to
room temperature. After removal of solvents, 100 mL of pentane
were added to the residue and the resulting mixture was filtrated

2298
L. Baiget et al. / Journal of Organometallic Chemistry 693 (2008) 2293–2298
(c) L. Baiget, H. Ranaivonjatovo, J. Escudié, G. Cretiu Nemes, I. Silaghi-
4.10. Synthesis of [R2C@C(Cl)]2SbCl 13b
Dumitescu, L. Silaghi-Dumitrescu, J. Organomet. Chem. 690 (2005) 307;
(d) L. Rigon, H. Ranaivonjatovo, J. Escudié, A. Dubourg, J.-P. Declercq, Chem.
Eur. J. 5 (1999) 774;
(e) M. Chentit, H. Sidorenkova, S. Choua, M. Geoffroy, Y. Ellinger, G.
Bernardinelli, J. Organomet. Chem. 634 (2001) 136;
(f) G. Cretiu Nemes, H. Ranaivonjatovo, J. Escudié, I. Silaghi-Dumitrescu, L.
Silaghi-Dumitrescu, H. Gornitzka, Eur. J. Inorg. Chem. (2005) 1109;
(g) M. Yoshifuji, S. Sasaki, N. Inamoto, Tetrahedron Lett. 30 (1989) 839;
(h) Y. El Harouch, H. Gornitzka, H. Ranaivonjatovo, J. Escudié, J. Organomet.
Chem. 643–644 (2002) 202;
Compound 13b was prepared according to the same experi-
mental process as 13a from 4.3 mL (7 mmol) of a solution of n-BuLi
(1.6 M in hexane), (2.5 g, 7 mmol) of dichlorofulvene 12b in 15 mL
of THF and (0.79 g, 7 mmol) of SbCl3 in 15 mL of THF. 2.07 g (83%)
of yellow crystals of [R2C@C(Cl)]2SbCl 13b (mp 250 °C) were
obtained.
1H NMR (300.13 MHz): d 1.09 (s, 18H, t-Bu), 1.31 (s, 18H, t-Bu),
(i) P.M. Petrar, G. Nemes, I. Silaghi-Dumitrescu, H. Ranaivonjatovo, H.
Gornitzka, J. Escudié, Chem. Commun. (2007) 4149.
[2] (a) K.B. Dillon, F. Mathey, J.F. Nixon, Phosphorus: The Carbon Copy, Wiley,
Chichester, 1998;
3
4
7.31 (dd, JHH = 8.0 Hz, JHH = 1.7 Hz, 2H, H on C6 or C3), 7.37 (dd,
3JHH = 8.0 Hz, JHH = 1.7 Hz, 2H,
H
H
on C3 or C6), 7.1 (dd,
4
4JHH = 1.7 Hz, JHH = 0.5 Hz, 2H,
on C8 or C1), 7.51 (d,
5
(b) R. Appel, Multiple Bonds and Low Coordination in Phosphorus Chemistry,
Georg Thieme, Verlag, Stuttgart, 1990. p. 157;
3JHH = 8.0 Hz, 2H, H on C5 or C4), 7.52 (d, JHH = 8.0 Hz, 2H, H on
3
4
5
(c) L.N. Markovski, V.D. Romanenko, Tetrahedron 45 (1989) 6019;
(d) L. Weber, Angew. Chem., Int. Ed. Engl. 35 (1996) 271;
(e) L. Weber, Eur. J. Inorg. Chem. (2000) 2425.
C4 or C5), 8,64 (dd, JHH = 1.7 Hz, JHH = 0.5 Hz, 2H, H on C1 or
C8); 13C NMR (75.47 MHz): d 31.2 and 31.5 (CMe3), 34.8 and 35.0
(CMe3), 119.0, 119.7, 120.9, 124.7, 126.5 and 126.9 (arom CH of
CR2), 138.3, 138.4, 138.5, 142.4, 149.6 and 150.3 (C@CCl and arom
C of CR2), 150.8 (CCl); MS (EI, 70 eV, m/z, %): 804 (M, 1), 646
(MꢀSbCl, 3), 631 (MꢀSbClꢀMe, 2), 611 (MꢀSbClꢀCl, 20), 576
(MꢀSbClꢀ2Cl, 18), 481 (MꢀCClCR2, 12), 310 (CR2+Clꢀ1, 26), 273
(CR2ꢀ3, 26), 193 (SbCl2, 60), 158 (SbCl, 10), 123 (Sb, 20), 57 (t-
Bu, 100); Anal. Calc. for C44H48Cl3Sb: C, 65.65; H 6.01. Found: C,
65.89; H, 5.95%.
[3] M. Gouygou, C. Tachon, R. El Ouatib, O. Ramarijoana, G. Etemad-Moghadam, M.
Koenig, Tetrahedron Lett. 30 (1989) 177.
[4] H. Ranaivonjatovo, H. Ramdane, H. Gornitzka, J. Escudié, J. Satgé,
Organometallics 17 (1998) 1631.
[5] (a) M. Yoshifuji, H. Kawanami, Y. Kawai, K. Toyota, M. Yasunami, T. Niitsu, N.
Inamoto, Chem. Lett. 6 (1992) 1053;
(b) E. Niecke, M. Nieger, O. Schmidt, D. Gudat, W.W. Schoeller, J. Am. Chem.
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(c) M. Van der Sluis, J.B.M. Wit, F. Bickelhaupt, Organometallics 15 (1996) 174.
[6] S. Lochschmidt, A. Schmidpeter, Phosphorus Sulfur 29 (1986) 73.
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Yoshifuji, Angew. Chem., Int. Ed. 39 (2000) 4512;
4.11. X-ray structure determinations
(b) T. Minami, H. Okamoto, S. Ikeda, R. Tanaka, F. Ozawa, M. Yoshifuji, Angew.
Chem., Int. Ed. 40 (2001) 4501;
(c) F. Ozawa, H. Okamoto, S. Kawagishi, S. Yamamoto, T. Minami, M. Yoshifuji,
J. Am. Chem. Soc. 124 (2002) 10968.
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[9] (a) L. Maier, D. Seyferth, F.G.A. Stone, E.G. Rochow, J. Am. Chem. Soc. 79 (1957)
5884;
All data for all structures represented in this paper were col-
lected at low temperatures by using an oil-coated shock-cooled
crystal on a Bruker-AXS CCD 1000 diffractometer with Mo Ka radi-
ation (k = 0.71073 Å). The structures were solved by direct meth-
ods [14] and all non hydrogen atoms were refined anisotropically
by using the least-squares method on F2 [15].
(b) R.N. Sterlin, R.D. Yatsenko, L.N. Pinkina, I.L. Knuyants, Izv. Akad. Nauk SSSR,
Ser. Khim. (1960) 1991;
(c) A.N. Nesmeyanov, A.E. Borisov, N.V. Novikova, Izv. Akad. Nauk SSSR, Ser.
Khim. (1961) 1578;
(d) A. Kiennemann, R. Kieffer, Bull. Soc. Chim. Fr. (1975) 1185;
(e) W. Levason, C.A. McAuliffe, S.G. Murray, J. Organomet. Chem. 88 (1975)
171;
Acknowledgements
(f) A.J. Ashe III, E.G. Ludwig Jr., H. Pommerening, Organometallics 2 (1983)
1573;
(g) S. Legoupy, L. Lassalle, J.-C. Guillemin, V. Metail, A. Senio, G. Pfister-
Guillouzo, Inorg. Chem. 34 (1995) 1466;
The authors thank the Centre National de la Recherche Scientif-
ique and the French Ministry of National Education for financial
supports.
(h) L. Lassalle, S. Legoupy, J.-C. Guillemin, Organometallics 15 (1996) 3466;
(i) J.-C. Guillemin, K. Malagu, Organometallics 18 (1999) 5259;
(j) M. Lahrech, J. Thibonnet, S. Hacini, M. Santelli, J.-L. Parrain, Chem. Commun.
(2002) 644.
Appendix A. Supplementary material
[10] Y. Sprinzak, J. Am. Chem. Soc. 80 (1958) 5449.
[11] H. Rezaei, J.F. Normant, Synthesis 1 (2000) 109.
[12] (a) A.H. Cowley, N.C. Norman, M. Pakulski, D.L. Bricker, D.H. Russell, J. Am.
Chem. Soc. 107 (1985) 8211;
(b) M.A. Mohammed, K.E. Ebert, H. Breunig, Z. Naturforsch., B: Chem. Sci. 51
(1996) 149.
[13] B. Twamley, C.D. Sofield, M.M. Olmstead, P.P. Power, J. Am. Chem. Soc. 107
(1985) 8211.
CCDC 679867 and 679868 contain the supplementary crystallo-
graphic data for 12b and 13a. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif. Supplementary data associ-
ated with this article can be found, in the online version, at
doi:10.1016/j.jorganchem.2008.04.012.
[14] G.M. Sheldrick, Acta Crystallogr., Sect. A 46 (1990) 467.
[15] G.M. Sheldrick, SHELXL-97, Program for Crystal Structure Refinement, University
of Göttingen, 1997.
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