The first stable 3,1-germaphosphaallene Tip(t-Bu)Ge=C=PAr

Article abstract of DOI:10.1016/S0022-328X(01)01223-2

The first stable heteroallenic derivative with two heavy doubly-bonded Group 14 and 15 elements, the germaphosphaallene Tip(t-Bu)Ge=C=PAr 1 (Tip = 2,4,6-triisopropylphenyl, Ar = 2,4,6-tri-tert-butylphenyl), has been prepared in a nearly quantitative yield by dechlorofluorination of Tip(t-Bu)Ge(F)-C(C1)=PAr (obtained from ArP=CC1₂ and successive reaction with n-butyllithium and Tip(t-Bu)GeF₂) with tert-butyllithium. 1 gives [2 + 2] cycloadducts by the Ge=C double bond with benzaldehyde, benzophenone and fluorenone to afford the corresponding germaoxetanes 11 - 13. 13 has been structurally characterized showing a long Ge-O bond (1.821(2) ?) and a slightly folded four-membered ring GeOCC (18.8° along C(1)Ge axis).

Full text of DOI:10.1016/S0022-328X(01)01223-2

Journal of Organometallic Chemistry 643–644 (2002) 202–208
www.elsevier.com/locate/jorganchem
The first stable 3,1-germaphosphaallene Tip(t-Bu)GeꢀCꢀPAr
Yamna El Harouch, Heinz Gornitzka, Henri Ranaivonjatovo, Jean Escudie´ *
He´te´rochimie Fondamentale et Applique´e, UMR 5069, Uni6ersite´ P. Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 04, France
Received 29 June 2001; accepted 5 September 2001
Dedicated to Professor Franc¸ois Mathey on the occasion of his 60th birthday
Abstract
The first stable heteroallenic derivative with two heavy doubly-bonded Group 14 and 15 elements, the germaphosphaallene
Tip(t-Bu)GeꢀCꢀPAr 1 (Tip=2,4,6-triisopropylphenyl, Ar=2,4,6-tri-tert-butylphenyl), has been prepared in a nearly quantitative
yield by dechlorofluorination of Tip(t-Bu)Ge(F)ꢁC(Cl)ꢀPAr (obtained from ArPꢀCCl2 and successive reaction with n-butyllithium
and Tip(t-Bu)GeF2) with tert-butyllithium. 1 gives [2+2] cycloadducts by the GeꢀC double bond with benzaldehyde, benzophe-
none and fluorenone to afford the corresponding germaoxetanes 11–13. 13 has been structurally characterized showing a long
,
GeꢁO bond (1.821(2) A) and a slightly folded four-membered ring GeOCC (18.8° along C(1)Ge axis). © 2002 Elsevier Science
B.V. All rights reserved.
Keywords: Germaphosphaallene; Doubly-bonded derivatives of germanium and phosphorus; [2+2] Cycloadditions; Germaoxetanes
labile Si (or Sn)ꢁC bond and they can be better de-
scribed as silylene-CO adducts and silylenes (or stan-
nylene)-isocyanide adducts rather than heteroallenes.
In the field of EꢀCꢀE% derivatives, with two heavy
elements of Groups 14 and 15, no stable compounds
could be obtained until now. The only ones to be
reported were the 3,1-phosphasilaallene Tip(Ph)SiꢀCꢀ
PAr (Tip=2,4,6-i-Pr3C6H2; Ar=2,4,6-t-Bu3C6H2) [10]
and the 3,1-germaphosphaallene Mes2GeꢀCꢀPAr
(Mes=2,4,6-Me3C6H2) [11] which have been evidenced
by NMR and by trapping reactions at low temperature.
Due to their very low thermal stability, dimerization
occurs rapidly above −40 °C. However, such com-
pounds keep their structural integrity in solution and
their bonding is closer to those of metallaallenes
ꢂEꢀCꢀCꢃ than those of SiCO and Si (or Sn) CN
compounds.
1. Introduction
As almost all the possible combinations of EꢀE%
compounds (E, E%=Group 14, 15 and 16 elements)
have been reported in the literature over the last 20
years, an exciting challenge was now the synthesis and
the stabilization of compounds with two cumulative
double bonds of the type EꢀCꢀE%. Many heteroallenes
of heavy Group 15 elements such as ꢁPꢀCꢀE% (E%=C,
N, P, As, O, S) have now been described [1,2]. By
contrast, heteroallenes with at least one heavy Group
14 element are much more rare [2,3] since in the field of
ꢂEꢀCꢀE% derivatives (E=Si, Ge, Sn; E%=C, N, P, O)
only some 1-silaallenes ꢂSiꢀCꢀCꢃ [4] and 1-germaal-
lenes ꢂGeꢀCꢀCꢃ [5] have been isolated and some
transient 1-silaallenes spectroscopically characterized
[6].
We describe in this paper the synthesis, the physico-
chemical study and some preliminary aspects of the
reactivity of the 3-(2,4,6-triisopropylphenyl)-3-tert-
butyl-1-(2,4,6-tri-tert-butylphenyl)-3-germa-1-phos-
phaallene 1, which is the first heteroallenic derivative
with two heavy doubly-bonded Group 14 and 15 ele-
ments stabilized at room temperature owing to bulky
groups on germanium and phosphorus.
By contrast with the ꢂEꢀCꢀCꢃ derivatives which
keep their ECC skeleton in trapping reactions, SiCO
[7], SiCN [8] and SnCN [9] derivatives have a very
* Corresponding author. Tel.: +33-5-61558347; fax: +33-5-
61558204.
E-mail address: escudie@chimie.ups-tlse.fr (J. Escudie´).
0022-328X/02/$ - see front matter © 2002 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(01)01223-2

Y.E. Harouch et al. / Journal of Organometallic Chemistry 643–644 (2002) 202–208
203
2. Results and discussion
prepared by reaction with hydrofluoric acid in water
(Scheme 1).
2.1. Synthesis of 1
Starting from the dichlorophosphaalkene 6 [12], the
germylphosphaalkene 7 was prepared by successive ad-
dition of n-butyllithium at low temperature and difl-
uorogermane 5 (Scheme 2).
Compound 7 was obtained in the form of only one
isomer. We suggest it is the Z isomer from the most
probable mechanism supposed to occur, involving a
halogen–metal exchange with n-butyllithium from the
least hindered side, i.e. the E-chlorine, to give the
transient carbenoid 8. Such a stereochemistry was pre-
viously reported [13].
As the GeꢀC double bond was supposed to be much
more reactive than the PꢀC double bond, the creation
of this GeꢀC unsaturation was the final step of the
synthesis.
From TipBr, 2 is obtained as a mixture of chloro-
and bromogermanes which can be converted to the
corresponding trimethoxygermane 3 without purifica-
tion. Addition of tert-butyllithium to 3 afforded the
dimethoxygermane 4. The difluorogermane 5 was then
The great steric hindrance occurring in 7 was clearly
1
evidenced in its H-NMR spectrum: two signals for the
o-t-Bu groups and a very broad signal for the methyls
of o-CHMe2 groups were observed due to the hindered
rotation of the Ar and Tip groups.
Addition of one equivalent of tert-butyllithium at
−90 °C led nearly quantitatively to the germaphos-
phaallene 1 probably via the intermediate 9 (Scheme 3).
Unfortunately, the obtaining of a single crystal suit-
able for an X-ray determination failed. However, the
NMR studies proved unambiguously the allenic struc-
ture of 1. The 13C chemical shift for the carbon bonded
Scheme 1.
1
to germanium and phosphorus (280.4 ppm, JPC=60.9
Hz) is characteristic of an allenic carbon [1–3] (for
example: 280.9 ppm in ArPꢀCꢀGeMes2 [11], 299.5 ppm
in ArPꢀCꢀAsAr [14], 269.1 ppm in Tip(Ph)SiꢀCꢀPAr
[10], 235.1 in Tip2GeꢀCꢀC(Ph)t-Bu [5c] and 243.5 in
Tbt(Mes)GeꢀCꢀCR2 (CR2=fluorenylidene, Tbt=
2,4,6-tris[bis(trimethylsilyl)methyl]phenyl) [5b]). The
low-field chemical shift in 31P-NMR (249.9 ppm) is also
consistent with the assigned structure (l 31P: 240 ppm
in Mes2GeꢀCꢀPAr [11]).
Scheme 2.
The germaphosphaallene 1 is the first stable allenic
compound with two heavy Group 14 and 15 elements.
Orange solutions of 1 in pentane or toluene are ex-
tremely air and moisture sensitive but under inert atmo-
sphere, they are recovered unchanged after at least 2
weeks at room temperature.
1 presents a chemical behaviour rather different from
that of the two transient metallaphosphaallenes previ-
ously described, the germaphosphaallene Mes2GeꢀCꢀ
PAr [11] and the phosphasilaallene Tip(Ph)SiꢀCꢀPAr
[10] which give two types of dimers, a head-to-tail
dimer by two MꢀC bonds (M=Si, Ge) and an unsym-
metrical dimer by one MꢀC and one PꢀC bonds above
−40 °C.
Scheme 3.
2.2. Reacti6ity of 1
Water adds regiospecifically to the GeꢀC unsatura-
tion of 1 to give the corresponding adduct 10 with the
hydroxy moiety bonded as expected to the germanium
due to the Ged+ꢁCd− polarity (Scheme 4). It has not
Scheme 4.

204
Y.E. Harouch et al. / Journal of Organometallic Chemistry 643–644 (2002) 202–208
bond. In heterocycle 11 formed from benzaldehyde, as
germanium and the carbon bonded to oxygen are chi-
ral, two diastereoisomers are obtained as expected in
the ratio 65/35. In the three germaoxetanes 11–13 only
one geometric isomer was obtained relatively to the
exocyclic PꢀC double bond. The X-ray study of 13
shows it is the Z-isomer; although 13-Z is the most
hindered isomer, its formation can be easily explained
since it arises from the preferential addition of
fluorenone to the less hindered side of the GeꢀC double
bond, i.e. in cis to the lone pair of phosphorus. Thus,
the Ar and Ge(t-Bu)Tip groups are in cis position. We
suppose to obtain the same stereochemistry in 11 and
12.
In the reaction of the silaallene Tip2SiꢀCꢀC(t-Bu)Ph
with benzophenone, [4c] West observed the formation
of a four-membered ring silaoxetane (cycloaddition be-
tween SiꢀC and CꢀO double bonds) and the presence as
major compound, like in our case, of the more hindered
isomer (Si and t-Bu groups in cis). However, due to a
lower difference of steric hindrance between t-Bu and
phenyl groups, he obtained also the other isomer in a
minor ratio.
The great difference in size between Ar and the
phosphorus lone pair explains the formation of the sole
13-Z.
The structure of the germaoxetane 13 has been
proved by an X-ray crystallographic analysis (Fig. 1
and Tables 1 and 2).
The four-membered ring is slightly folded: the angles
between the C(1)OGe and C(1)C(14)Ge planes is 18.9°
and between OC(1)C(14) and OGeC(14) 18.7°. A simi-
lar folding was determined in other 2-germaoxetanes
[15] and 2-silaoxetanes [16]. It is greater than the fold-
ing in 1,3-digermaoxetanes [17] but less important than
the one reported in 1,3-digermazanes [18].
Fig. 1. Molecular structure of 13. Ellipsoids are drawn at 50%
probability level. Hydrogen atoms and the molecule of CHCl3 are
omitted for clarity.
Table 1
,
Selected bond lengths (A), bond angles (°) and torsion angles (°) in
germaoxetane (13)
Bond lengths
C(1)ꢁO
GeꢁO
C(1)ꢁC(14)
GeꢁC(14)
C(1)ꢁC(2)
C(1)ꢁC(13)
GeꢁC(15)
GeꢁC(19)
PꢁC(14)
PꢁC(34)
1.450(4)
1.826(2)
1.552(5)
2.003(3)
1.531(5)
1.526(4)
1.983(3)
1.981(3)
1.661(4)
1.853(3)
Bond angles
OꢁGeꢁC(14)
GeꢁOꢁC(1)
OꢁC(1)ꢁC(14)
C(1)ꢁC(14)ꢁGe
GeꢁC(14)ꢁP
C(1)ꢁC(14)ꢁP
C(14)ꢁPꢁC(34)
C(15)ꢁGeꢁC(19)
OꢁGeꢁC(19)
C(14)ꢁGeꢁC(15)
74.07(12)
96.09(18)
100.6(2)
86.1(2)
152.70(19)
119.3(2)
106.74(16)
114.97(14)
105.65(13)
118.01(13)
,
The GeꢁO bond length (1.826(2) A) is somewhat
longer than the standard corresponding bond (standard
,
range: 1.73–1.80 A) [19,20] and is comparable to the
one measured in other germaoxetanes with the germa-
nium atom substituted by bulky groups [15]. However,
,
a longer GeꢁO bond length (1.872(4) A) has been
,
Distances to the mean plane C(1)ꢁC(14)ꢁOꢁGe: C(1): +0.1144 A;
,
,
,
C(14): −0.0847 A, O: −0.1004 A, Ge: +0.0706 A.
reported in an extremely congested oxazagermete ring
system [21]. The GeꢁC bond in the four-membered ring
,
(2.003(3) A) is also rather long (normal GeꢁC distances
been possible from the PꢁH coupling constant (25.0
Hz) to determine its stereochemistry Z or E by com-
parison with the literature data on the similar C-
germylphosphaalkene ArPꢀC(H)GeMe3 [12]; the latter
displays 2JPH constants of respectively 26.4 Hz for the E
and 23.5 Hz for the Z isomer [12], both close to the
constant determined in 10.
Aldehydes such as benzaldehyde and ketones such as
benzophenone and fluorenone react with the GeꢀC
double bond of 1 to give [2+2] cycloadducts. The
germaoxetanes 11–13 are air and moisture stable and
are the first germaoxetanes with an exocyclic double
,
are generally between 1.90 and 2.00 A [20,22]). The
small angle of 74.07(12)° at the germanium atom is not
unusual; similar values have been reported in other
four-membered ring derivatives of germanium: for ex-
ample 74.1° in a 3,4-digerma-1,2-dioxetane [17], 75.0 in
a 2-germaphosphetene [23], 75(1) and 75.6(2) in 2-ger-
maoxetanes [15]. The carbon atom of the CꢀP double
bond is almost planar (sum of angles: 358.1°). The
exocyclic CꢀP bond is slightly twisted with a twist angle
of 10.5° between the C(1)C(14)Ge and C(14)PC(33)
planes. The bond lengths and bond angles within the
Tip, Ar and fluorenyl groups span the normal limits.

Y.E. Harouch et al. / Journal of Organometallic Chemistry 643–644 (2002) 202–208
205
In conclusion, the title germaphosphaallene is the first
3.1. 2,4,6-Triisopropylphenyl(trimethoxy)germane (3)
compound of this type stable as a monomer. Despite the
great steric hindrance necessary for its stabilization, it
presents a very reactive GeꢀC double bond towards
water or carbonyl compounds, while the PꢀC double
bond is inert in these reactions. The intensive study of
the chemical behavior of such a derivative is under
investigation.
To a solution of TipGeCl3 (4.64 g, 12.0 mmol) in
toluene (40 ml) were added 15 ml of CH3OH and 10 ml
of triethylamine. The reaction mixture was refluxed for
1 h. After warming to room temperature (r.t.), the
solvents were removed in vacuo and 100 ml of pentane
were added. Et3N·HCl was filtered out. After removal of
pentane, 3.92 g (87%) of 3 were obtained as a viscous oil.
1H-NMR: l 1.24 (d, 3JHH=6.7 Hz, 18H, o and
3
3. Experimental
p-CHMe2); 2.87 (sept, JHH=6.7 Hz, 1H, p-CHMe2);
3
3.41 (sept, JHH=6.7 Hz, 2H, o-CHMe2); 3.67 (s, 9H,
All reactions were carried out under N2 or Ar with
carefully dried solvents. NMR spectra were recorded on
Bruker AC 80, AC 200 and AC 250 at the respective
frequencies (1H: 80.13, 200.13 and 250.13 MHz), 13C
(50.323 and 62.896 MHz), 19F (ref. CF3COOH, 188.298
MHz) and 31P (ref. H3PO4, 81.015 MHz); when no NMR
solvent is mentioned, it was CDCl3. Mass spectra
were obtained from a Hewlett–Packard HP 5989 spec-
trometer in the electron-impact mode (70 eV). Melting
points (m.p.) were measured on a Leitz microscope.
OMe); 7.08 (s, 2H, arom H). Anal. Found: C, 58.79; H,
8.92. Calc. for C18H32GeO3: C, 58.58; H, 8.74%.
3.2. 2,4,6-Triisopropylphenyl(tert-butyl)dimethoxy-
germane (4)
A solution of tert-butyllithium 1.6 M in pentane (5 ml,
7.8 mmol) was slowly added to a solution of 3 (2.80 g,
7.60 mmol) in pentane (30 ml) cooled to 0 °C. After the
end of the addition, the reaction mixture was refluxed for
1 h, then cooled to r.t.; 1 ml of methyl iodide (to
transform MeOLi to LiI and Me2O) was added and LiI
was filtered out. Crystallization from pentane afforded
2.25 g of white crystals of 4 (75%), m.p. 112 °C.
Table 2
Crystal data and structure refinement parameters for compound 13
3
1H-NMR: l 1.18 (s, 9H, CMe3); 1.24 (d, JHH=7.0
3
Hz, 18H, o and p-CHMe2); 2.86 (sept, JHH=6.9 Hz,
Empirical formula
Formula weight
Temperature (K)
C51H69GeOP·CHCl3
920.99
193(2)
1H, p-CHMe2); 3.39 (sept, 3JHH=6.7 Hz, 2H, o-
CHMe2); 3.65 (s, 6H, OMe); 7.05 (s, 2H, arom H).
13C-NMR: l 23.83 (p-CHMe2); 25.78 (o-CHMe2);
27.62 (CMe3); 29.72 (CMe3); 34.08 (o and p-CHMe2);
53.05 (OMe); 122.17 (m-CH Tip); 126.80 (ipso-C Tip);
150.56 (p-C Tip); 155.93 (o-C Tip).
,
Wavelength (A)
Crystal system
Space group
0.71073
Triclinic
P1
,
a (A)
10.1917(8)
13.4654(11)
19.1643(15)
82.962(2)
83.578(2)
72.0340(10)
2475.3(3)
2
,
b (A)
,
c (A)
MS: 364 [M−OMe−H, 33]; 339 [M−t-Bu, 48]; 333
[M−2OMe−1, 2]; 307 [M−t-Bu−OMe−1, 47]; 275
[M−2OMe−t-Bu−2, 100]; 57 (t-Bu, 97).
Anal. Found: C, 64.04; H, 9.78. Calc. for C21H38GeO2:
C, 63.84; H, 9.69%.
h (°)
i (°)
k (°)
3
,
V (A )
Z
Dcalc (Mg m−3
)
1.236
0.848
976
Absorption coefficient (mm−1
F(000)
)
3.3. Difluoro(2,4,6-triisopropylphenyl)(tert-butyl)-
germane (5)
Crystal size (mm)
0.3×0.5×0.6
Theta range for data collection (°) 1.60–24.71
Index ranges
−115h511, −155k515,
225l522
12 153
8342 [Rint=0.0471]
98.7%
To a solution of 4 (1.52 g, 3.8 mmol) in 15 ml of C6H6
was added a solution at 40% of HF in H2O (5 ml, large
excess). After 1 h at reflux, the two layers were separated.
The aq. layer was extracted with Et2O. After drying over
Na2SO4 and removal of solvents in vacuo, crude 5 was
crystallized from pentane to give 1.12 g (78%) of white
crystals. m.p. 104–106 °C.
Reflections collected
Independent reflections
Completeness to q=26.37°
Absorption correction
Refinement method
None
Full-matrix least-squares on
F2
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I\2|(I)]
R indices (all data)
8342/158/596
0.981
R1=0.0489, wR2=0.1288
R1=0.0683, wR2=0.1366
0.474 and −0.720
3
1H-NMR: l 1.24 (d, JHH=6.8 Hz, 6H, p-CHMe2);
4
3
1.28 (t, JHF=1.6 Hz, 9H, CMe3); 1.28 (d, JHH=6.8
Hz, 12H, o-CHMe2); 2.88 (t, sept, 3JHH=6.8 Hz,
Largest difference peak and hole
5JHF=2.2 Hz, 2H, o-CHMe2); 2.94 (sept, JHH=6.8
3
−3
,
(e A
)
Hz, 1H, p-CHMe2); 7.09 (s, 2H, arom H).

206
Y.E. Harouch et al. / Journal of Organometallic Chemistry 643–644 (2002) 202–208
13C-NMR: l 23.81 (p-CHMe2); 25.21 (o-CHMe2);
giving a red-orange solution. A 31P-NMR analysis
showed the nearly quantitative formation of the
germaphosphaallene 1. Solutions of 1 can be used
directly without further purification. After removal of
solvents in vacuo, C6D6 was added to the crude crys-
talline product for NMR.
25.94 (CMe3); 34.39 (p-CHMe2); 36.22 (t, 5JCF=3.2
Hz, o-CHMe2); 122.46 (m-CH Tip); 152.74 (p-C Tip);
155.27 (o-C Tip). 19F-NMR: l −83.7 ppm.
MS: 372 [M, 6]; 352 [M−F−1, 2]; 316 [M−t-Bu+
1, 12]; 295 [M−F−t-Bu−1, 20]; 277 [M−2F−t-Bu,
15]; 203 (Tip, 30); 27 (t-Bu, 100).
1H-NMR (C6D6): l 0.99, 1.24, 1.43 and 1.51 (4d,
3
Anal. Found: C, 61.58; H, 8.91. Calc. for
C19H32F2Ge: C, 61.50; H, 8.69%.
3JHH=6.8 Hz, 4×3H, o-CHMe2); 1.20 (d, JHH=6.8
Hz, 6H, p-CHMe2); 1.32 and 1.36 (2s, 2×9H, p-CMe3
and GeCMe3); 1.72 (s, 18H, o-CMe3); 2.79, 2.89 and
3
3.4. Synthesis of 7
3.46 (3 sept, JHH=6.8 Hz, 3×1H, o and p-CHMe2);
4
7.07 and 7.13 (2s, 2H, arom H Tip); 7.52 (d, JHP=0.6
A solution of ArPꢀCCl2 [12] (2.83 g, 7.8 mmol) in
THF (60 ml) was cooled to −90 °C. A solution of
n-butyllithium 1.6 M in hexane (5.2 ml, 8 mmol) was
slowly added at −90 °C then the reaction mixture was
stirred for 30 min at −70 °C. A solution of 5 (2.92 g,
7.8 mmol) in THF (60 ml) was added at this tempera-
ture. After 30 min at −70 °C, the reaction mixture
was allowed to warm to r.t. Solvents were evaporated
in vacuo, 100 ml of pentane were added and LiF was
removed by filtration. Crystallization from pentane
gave 2.15 g of 7 (41%), m.p. 142–144 °C.
Hz, arom H Ar).
13C-NMR (C6D6): l 24.21 (p-CHMe2); 23.97, 24.51,
25.17 and 25.84 (o-CHMe2); 30.59 and 31.70 (p-CMe3
1
and GeCMe3); 34.12 (d, JCP=4.1 Hz, GeCMe3); 34.29
(d, 4JCP=8.3 Hz, o-CMe3); 34.72 (p-CHMe2); 35.02
(p-CMe3); 38.63 (o-CMe3); 40.84 and 41.42 (o-
CHMe2); 121.52 and 121.60 (m-CH Tip); 121.95 (m-
3
CH Ar), 133.20 (d, JCP=5.5 Hz, ipso-C Tip); 145.43
1
(d, JCP=87.0 Hz, ipso-C Ar); 148.69 and 151.47 (p-C
2
Ar and Tip); 152.24 (d, JCP=2.1 Hz, o-C Ar); 153.26
1
and 153.64 (o-C Tip); 280.82 (d, JCP=62.1 Hz, ꢀCꢀ).
1H-NMR: l 1.23 (d, 3JHH=6.8 Hz, 18H, o and
31P-NMR (C6D6): l 249.9.
4
p-CHMe2); 1.31 (s, 9H, p-CMe3); 1.37 (d, JHF=1.4
MS: 622 [M, 6]; 565 [M−t-Bu, 3]; 509 [M−2t-
Bu+1, 13]; 465 [M−2t-Bu−i-Pr, 2]; 451 [M−3t-Bu,
3]; 379 [M−Ar+2, 13]; 347 [M−ArP+1, 3]; 320
[M−Ar−t-Bu, 3]; 289 [M−ArP−t-Bu, 12]; 275
(ArP−1, 25); 245 (Ar, 5); 203 (Tip, 4); 57 (t-Bu, 100).
Hz, 9H, GeCMe3); 1.47 (d, 5JHP=0.5 Hz, 9H, o-
5
CMe3); 1.51 (d, JHP=0.7 Hz, 9H, o-CMe3); 2.86 (sept,
3JHH=6.8 Hz, 3H, o and p-CHMe2); 7.04 (s, 2H, arom
4
H Tip); 7.39 (d, JHP=1.5 Hz, 2H, arom H Ar).
13C-NMR: l 23.85 (p-CHMe2); 26.49 (o-CHMe2);
3
2
28.3 (d, JCF=4.5 Hz, GeCMe3); 32.08 (d, JCF=10.5
Hz, GeCMe3); 32.81, 32.95, 33.10, 34.08 (o and p-
3.6. Hydrolysis of 1
3
CHMe2); 35.08 (p-CMe3); 37.87 (d, JCP=6.6 Hz, o-
CMe3); 121.73, 122.30 (m-CH Ar and Tip); 127.41 (d,
To a solution of 1 prepared from 1.04 g of 7, in Et2O
(10 ml), was added an excess of H2O at r.t. The
orange–red color turned immediately yellow. After re-
moval of solvents in vacuo, pentane was added and the
reaction mixture dried over Na2SO4. Crystallization at
−20 °C from pentane gave 0.73 g of 10 in about 90%
purity (75% yield in 10).
1
2JCF=6.5 Hz, ipso-C Tip); 134.41 (d, JCP=65.4 Hz,
ipso-C Ar); 150.72 (p-C Tip and p-C Ar); 153.18 (d,
3JCF=2.3 Hz, o-C Ar); 156.70 (o-C Tip); 169.31 (dd,
2
1JCP=88.4 Hz, JCF=9.5 Hz, PꢀCꢁCl).
3
19F-NMR: l−103.2 ppm (d, JFP=30.5 Hz).
3
31P-NMR: l 297.6 ppm (d, JPF=30.5 Hz).
3
MS: 675 [M−1, 1]; 657 [M−F, 1]; 641 [M−Cl, 2];
633 [M−i-Pr, 4]; 619 [M−t-Bu, 11]; 600 [M−t-Bu−
F, 2]; 577 [M−i-Pr−t-Bu+1, 7]; 324 (ArP−CCl+1,
11); 287 (ArPꢀC−1, 40); 275 (ArP−1, 27); 203 (Tip,
9); 57 (t-Bu, 100).
1H-NMR: l 0.99 and 1.20 (2d, JHH=6.7 Hz) and
1.32–1.42 (m, 18H, o and p-CHMe2); 1.27 and 1.31 (2s,
2×9H, p-CMe3 and GeCMe3); 1.50 (s, 18H, o-CMe3);
3
2.95 (sept, JHH=6.7 Hz, 1H, p-CHMe2); 3.30 (2 sept,
3JHH=6.7 Hz, 2H, o-CHMe2); 6.99 (s, 2H, arom H
4
Anal. Found: C, 67.58; H, 9.17. Calc. For
C38H61ClFGeP: C, 67.53; H, 9.10%.
Tip); 7.35 (d, JHP=1.1 Hz, 2H, arom H Ar); 8.04 (d,
2JHP=24.6 Hz, 1H, PꢀCH).
13C-NMR: l 23.91, 24.97, 26.28 and 28.08 (o and
p-CHMe2 and GeCMe3); 31.42, 31.72, 34.10, 34.17 and
34.53 (o and p-CHMe2 and o and p-CMe3); 29.82
(GeCMe3); 34.96 (p-CMe3); 38.15 (o-CMe3); 121.74
3.5. 3-(2,4,6-triisopropylphenyl)-3-tert-butyl-1-(2,4,6-
tri-tert-butylphenyl)germaphosphaallene (1)
3
To a solution of 7 (1.04 g, 1.54 mmol) in carefully
deoxygenated and dried Et2O cooled to −70 °C was
added one equivalent of a solution of tert-butyllithium
1.6 M in pentane (1.1 ml). The solution became imme-
diately red. After warming to r.t., LiF was filtered out
and 122.00 (m-CH Tip and Ar); 131.11 (d, JCP=6.0
1
Hz ipso-C Tip); 144.05 (d, JCP=69.9 Hz, ipso-C Ar);
149.78 and 149.80 (p-C Tip and Ar); 152.66 (o-C Ar);
155.15 (o-C Tip); 176.90 (d, 1JCP=72.2 Hz, PꢀCH).
3
31P-NMR: l 325.9 (d, JPH=24.9 Hz).

Y.E. Harouch et al. / Journal of Organometallic Chemistry 643–644 (2002) 202–208
207
MS: 639 [M−1, 3]; 623 [M−OH, 2]; 583 [M−t-Bu,
25]; 565 [M−t-Bu−H2O, 5]; 509 [M−2t-Bu−OH,
32]; 436 [M−Tip-1, 12]; 379 [M−t-Bu−Tip−1, 35];
351 (t-BuGe(Tip)OH, 5); 289 (ArPꢀCH, 12); 245 (Ar,
5); 233 (ArPꢀCH−t-Bu, 33); 203 (Tip, 10); 57 (t-Bu,
100).
(ipso-C Tip); 136.50 (d, 1JCP=65.9 Hz, ipso-C Ar);
137.81, 140.30 and 149.26 to 156.14 (o and p-C Tip and
1
Ar and C of CR2); 193.50 (d, JCP=60.9 Hz, PꢀC).
31P-NMR: l 314.0.
MS: 802 [M, 1]; 745 [m−t-Bu, 1]; 689 [m−2t-Bu+
1, 2]; 622 [M−R2CO, 1]; 579 [M−R2CO−i-Pr, 1];
565 [M−R2CO−t-Bu, 16]; 509 [M−R2CO−2t-Bu,
15]; 453 (ArPꢀCCR2+1, 2); 275 (ArP−1, 23); 203
(Tip, 2); 57 (t-Bu, 100).
3.7. Reaction of 1 with PhCHO, Ph2CO and R2CO
The typical procedure is described in the case of
fluorenone.
3.8. X-ray measurements of 13
To a solution of 1 in Et2O (prepared from 1.04 g,
1.54 mmol of 7 and one equivalent of t-BuLi) was
added a solution of fluorenone (0.28 g, 1.54 mmol) in
Et2O at r.t. The reaction mixture turned yellow. After 1
h stirring, the solvents were evaporated in vacuo and
replaced by pentane. Cooling at −20 °C gave light
yellow crystals of 13 (m.p. 227 °C, 0.75 g, 61%). 11 and
12 were obtained as viscous oils and could not be
completely purified. However, they were obtained in
more than 95% purity and were unambiguously iden-
tified by their physicochemical data;
Suitable crystals were obtained by crystallization
from CHCl3 at r.t. Crystal data for 13 are presented in
Table 2. All data were collected at low temperatures on
a Bruker-AXS CCD 1000 diffractometer with Mo–Ka
,
radiation (u=0.71073 A). The structure was solved by
direct methods by means of SHELXL-97 [24] and refined
with all data on F2 by means of SHELXS-97 [25]. All
non-hydrogen atoms were refined anisotropically. The
hydrogen atoms of the molecules were geometrically
idealized and refined using a riding model. Disorders of
a t-Bu- and a i-Pr-group has been refined with the help
of ADP and distances restraints.
11a: 1H-NMR: l 5.81 (d, 3JHP=14.2 Hz, CHPh),
2
13C-NMR: l 90.40 (d, JCP=20.3 Hz, CHPh), 193.31
1
(d, JCP=75.3 Hz, PꢀC), 31P-NMR: l 253.8 (d,3JPH
=
14 Hz).
11b: 1H-NMR: l 6.10 (d, 3JHP=16.8 Hz, CHPh).
4. Supplementary material
13C-NMR: l 90.72 (d, JCP=22.1 Hz, CHPh), 194.60
2
1
3
(d, JCP=76.4 Hz, PꢀC). 31P-NMR: l 257.7 (d, JPH
=
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC no. 166267 for compound 13.
Copies of this information may be obtained free of
charge from The Director, CCDC, 12, Union Road,
Cambridge CB2 1EZ, UK (Fax: +44-1223-336033;
e-mail: deposit@ccdc.camc.ac.uk or www: http://
www.ccdc.camc.ac.uk).
17.6 Hz)
MS: 728 [M, 1]; 671 [M−t-Bu, 3]; 615 [M−2t-
Bu+1, 3]; 565 [M−t-Bu−PhCHO, 2]; 509 [M−2t-
Bu-PhCHO+1, 2]; 435 (ArPꢀCꢁCHPh, 5); 377
(ArPꢀCꢀCPh, 3); 323 (ArPꢀCCl, 2); 235 (TipGeO−i-
Pr+H, 7); 105 (PhCHO−H, 3); 57 (t-Bu, 100).
1
12: H-NMR: l 0.92–1.82 (m, 54 H, o and p-t-Bu,
t-BuGe, CHMe2), 2.95 (sept, 3JHH=6.7 Hz, 2H, o-
3
CHMe2); (sept, JHH=6.7 Hz, 1H, p-CHMe2); 6.80–
8.17 (m, 14H, arom H Tip, Ar and Ph2). 13C-NMR: l
2
1
97.20 (d, JCP: 29.5 Hz, CPh2), 195.61 (d, JCP: 71.7 Hz,
Acknowledgements
PꢀC). 31P-NMR: l 328.2.
MS: 804 [M, 1]; 747 [M−t-Bu, 2]; 691 [M−2t-
Bu+1, 2]; 622 [M−Ph2CO, 2]; 600 [M−Tip−1, 2];
565 [M−Ph2CO−t-Bu, 17]; 559 [M−Ar, 3]; 544
[M−Tip−t-Bu, 2]; 509 [M−Ph2CO−2t-Bu+1, 13];
455 (ArPꢀCꢀCPh2+1, 3); 397 (ArPꢀCꢀCPh2−t-Bu,
3); 377 [M−Ph2CO−Ar, 13]; 350 (TipGe(O)t-Bu, 3);
293 (TipGeO, 24); 57 (t-Bu, 100).
Y.E.H. thanks the ‘Comite´ Mixte Inter-universitaire
Franco-Marocain’ (Action Inte´gre´e no 216 SM 00). The
authors thank INTAS (project no 97 30344) and the
CNRS for financial support.
References
1
3
13: H-NMR: l 0.90 (d, JHH=6.2 Hz) and 1.00–
1.43 (m, 18H, o and p-CHMe2); 1.10, 1.32, 1.34 and
1.52 (4s, 4×9H, o and p-CMe3); 2.05, 2.95 and 3.15 (3
[1] R. Appel, in: M. Regitz, O.J. Scherer (Eds.), Multiple Bonds and
Low Coordination in Phosphorus Chemistry, Thieme, Stuttgart,
1990, p. 157.
[2] J. Escudie´, H. Ranaivonjatovo, L. Rigon, Chem. Rev. 100 (2000)
3639.
[3] B. Eichler, R. West, Adv. Organomet. Chem. 46 (2001) 1.
[4] (a) G. Miracle, J.L. Ball, D.R. Powell, R. West, J. Am. Chem.
Soc. 115 (1993) 11598;
3
sept, JHH=6.7 Hz, 3×1H, o and p-CHMe2); 6.74–
7.55 (m, 12H, arom H Tip and Ar, CR2).
13C-NMR: l 23.97–36.27 (GeCMe3, CHMe2 and o
and p-CMe3); 29.76 (GeCMe3); 34.88 (p-CMe3); 38.18
(o-CMe3); 100.01 (d, 2JCP=38.7 Hz, RCO); 132.34

208
Y.E. Harouch et al. / Journal of Organometallic Chemistry 643–644 (2002) 202–208
(b) G.E. Miracle, J.L. Ball, S.R. Bielmeier, D.R. Powell, R.
[10] L. Rigon, H. Ranaivonjatovo, J. Escudie´, A. Dubourg, J.-P.
Declercq, Chem. Eur. J. 5 (1999) 774.
[11] H. Ramdane, H. Ranaivonjatovo, J. Escudie´, S. Mathieu, N.
Knouzi, Organometallics 15 (1996) 3070.
West, in: B. Marciniec, J. Chojnowski (Eds.), Progress in
Organosilicon Chemistry, Gordon and Breach Science Publish-
ers, Basel, 1995, p. 83;
(c) M. Trommer, G.E. Miracle, B.E. Eichler, D.R. Powell, R.
West, Organometallics 16 (1997) 5737;
(d) B.E. Eichler, G.E. Miracle, D.R. Powell, R. West, Main
Group Met. Chem. 22 (1999) 147.
[12] S.J. Goede, F. Bickelhaupt, Chem. Ber. 124 (1991) 2677.
[13] (a) M. Van der Sluis, J.B.M. Wit, F. Bickelhaupt, Organometal-
lics 15 (1996) 174;
(b) M. Yoshifuji, H. Kawanami, Y. Kawai, K. Toyota, M.
Yasunami, T. Niitsu, N. Inamoto, Chem. Lett. (1992) 1053;
(c) E. Niecke, M. Nieger, O. Schmidt, D. Gudat, W.W.
Schoeller, J. Am. Chem. Soc. 121 (1999) 519.
[5] (a) K. Kishikawa, N. Tokitoh, R. Okazaki, Organometallics 16
(1997) 5127;
(b) N. Tokitoh, K. Kishikawa, R. Okazaki, Chem. Lett. (1998)
811;
(c) B.E. Eichler, D.R. Powell, R. West, Organometallics 17
(1998) 2147;
(d) B.E. Eichler, D.R. Powell, R. West, Organometallics 18
(1999) 540.
[14] H. Ranaivonjatovo, H. Ramdane, H. Gornitzka, J. Escudie´, J.
Satge´, Organometallics 17 (1998) 1631.
[15] M. Lazraq, C. Couret, J. Escudie´, J. Satge´, M. Dra¨ger,
Organometallics 10 (1991) 1771.
[16] (a) A.G. Brook, W.J. Chatterton, J.F. Sawyer, D.W. Hughes, K.
Vorspohl, Organometallics 6 (1987) 1246;
(b) A.G. Brook, K. Vorspohl, R.R. Ford, M. Hesse, W.J.
Chatterton, Organometallics 6 (1987) 2128.
[17] S. Masamune, S.A. Batcheller, J. Park, W.M. Davis, O. Ya-
mashita, Y. Ohta, Y. Kabe, J. Am. Chem. Soc. 111 (1989) 1888.
[18] M. Lazraq, C. Couret, J.P. Declercq, A. Dubourg, J. Escudie´,
M. Rivie`re-Baudet, Organometallics 9 (1990) 845.
[19] L. Ross, M. Dra¨ger, Z. Naturforsch. 39B (1984) 868.
[20] K.M. Baines, W.G. Stibbs, Coord. Chem. Rev. 145 (1995) 157.
[21] T. Matsumoto, N. Tokitoh, R. Okazaki, Chem. Commun.
(1997) 1553.
[22] M. Dra¨ger, L. Ross, D. Simon, Rev. Silicon Germanium, Tin,
Lead Compound 7 (1983) 299.
[6] (a) C. Kerst, C.R. Ruffolo, W.J. Leigh, Organometallics 16
(1997) 5804;
(b) C. Kerst, C.W. Rogers, C.R. Ruffolo, W.J. Leigh, J. Am.
Chem. Soc. 119 (1997) 466.
[7] (a) G. Maier, H.P. Reisenauer, H. Egenolf, Organometallics 18
(1999) 2155;
(b) M.A. Pearsall, R. West, J. Am. Chem. Soc. 110 (1998) 7228;
(c) C.A. Arrington, J.T. Petty, S.E. Payne, W.C.K. Haskins, J.
Am. Chem. Soc. 110 (1998) 6240;
(d) M. Tacke, C. Klein, D.J. Stufkens, A. Oskam, P. Jutzi, E.A.
Bunte, Z. Anorg. Allg. Chem. 619 (1993) 865.
[8] (a) M. Weidenbruch, B. Brand-Roth, S. Pohl, W. Saak, Angew.
Chem. Int. Ed. Engl. 29 (1990) 90;
(b) M. Weidenbruch, B. Brand-Roth, S. Pohl, W. Saak, Polyhe-
dron 10 (1991) 1147;
(c) N. Takeda, H. Suzuki, N. Tokitoh, R. Okazaki, S. Nagase, J.
Am. Chem. Soc. 119 (1997) 1456.
[23] M. Andrianarison, C. Couret, J.-P. Declercq, A. Dubourg, J.
Escudie´, J. Satge´, J. Chem. Soc. Chem. Commun. (1987) 921.
[24] G.M. Sheldrick, Acta Crystallogr. Sect. A 46 (1990) 467.
[25] G.M. Sheldrick, SHELXL-97, Program for Crystal Structure
Refinement, Universita¨t Go¨ttingen, Germany, 1997.
[9] H. Gru¨tzmacher, S. Freitag, R. Herbst-Irmer, G.S. Sheldrick,
Angew. Chem. Int. Ed. Engl. 31 (1992) 437.