Reactivity of quinones with phosphagermaallene tip(tBu)Ge=C=PMes* leading to four- and six-membered heterocycles with an exocyclic P=C double bond

Article abstract of DOI:10.1002/ejic.201000747

Phosphagermaallene Tip(tBu)Ge=C=PMes* (1) (Tip = 2,4,6- triisopropylphenyl, Mes* = 2,4,6-tri-tert-butylphenyl) reacts with one equivalent of p-quinone (1,4-benzoquinone, 2,3,5,6-tetramethyl-1,4-benzoquinone, 1,4-naphthoquinone, and 9,10-anthraquinone) to

Full text of DOI:10.1002/ejic.201000747

FULL PAPER
DOI: 10.1002/ejic.201000747
Reactivity of Quinones with Phosphagermaallene Tip(tBu)Ge=C=PMes*
Leading to Four- and Six-Membered Heterocycles with an Exocyclic P=C
Double Bond
Dumitru Ghereg,[a] Heinz Gornitzka,[b] and Jean Escudié*[a]
Keywords: Main group elements / Germanium / Phosphorus / Cumulenes / Quinones / Cycloaddition
Phosphagermaallene Tip(tBu)Ge=C=PMes* (1) (Tip = 2,4,6-
triisopropylphenyl, Mes* = 2,4,6-tri-tert-butylphenyl) reacts
with one equivalent of p-quinone (1,4-benzoquinone, 2,3,5,6-
tetramethyl-1,4-benzoquinone, 1,4-naphthoquinone, and
9,10-anthraquinone) to form spiro 1-oxa-2-germacyclobut-
ane compounds 2–5 with an exocyclic P=C double bond by
[2 + 2] cycloaddition between the Ge=C and one of the C=O
double bonds. With two equivalents of 1 a double [2 + 2]
cycloaddition occurs involving both unsaturated C=O bonds
of 1,4-benzoquinone to give the dispiro compound 6. [2 + 4]
Cycloadditions are observed between the Ge=C double bond
of 1 and the O=C–C=O unit of an α-diketone (benzil) and an
o-quinone (9,10-phenanthrenequinone) to give the corre-
sponding 1,4-dioxa-2-germa-5-cyclohexenes 7 and 8.
Introduction
di-tert-butylfluorenylidene) towards quinones has been re-
Heteroalkenes E14=C (E14 = Si,[1] Ge,[2] Sn[2a,2d]) have ported very recently. Depending on the quinone, a variety
been intensively studied over the last three decades. Owing of reactions occur at the Ge=C double bond (Scheme 1).
to the great reactivity of the E14=C double bond, these
For example, [2 + 4] cycloadditions involving the O=C–
compounds are powerful building blocks in organometallic C=CH unit with naphthoquinone[3] and anthraquinone[4]
and heterocyclic chemistry. In the field of germanium un- and two different types of formal [2 + 3] cycloadditions
saturated derivatives, the reactivity of germene Mes2- involving the O=C–CH unit with naphthoquinone,[3] 1,4-
Ge=CR2 (Mes = 2,4,6-trimethylphenyl, CR2 = fluorenyl- benzoquinone,[5] and 2,3,5,6-tetramethyl-1,4-benzoquinone
idene) and, in some cases, of Mes2Ge=CRЈ2 (CRЈ2 = 2,7- have been observed.[5] Whatever the stoichiometry of the
Scheme 1. Reactivity of Mes2Ge=CR2 towards p-quinones.
reagents, the final product is formed from two molecules of
germene and one of quinone.
In order to understand the surprising reaction leading to
the five-membered ring oxagermacyclopentanes, DFT cal-
culations have been performed on 1,4-benzoquinone and
the model compound H2Ge=CH2. They predict that the
[b] CNRS, LCC (Laboratoire de Chimie de Coordination),
Université de Toulouse, UPS, INP, LCC,
205 route de Narbonne, 31077 Toulouse, cedex 4, France
[a] Université de Toulouse, UPS, LHFA; CNRS, LHFA, UMR
5069,
118 route de Narbonne, 31062 Toulouse, cedex 09, France
E-mail: escudie@chimie.ups-tlse.fr
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© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
281

D. Ghereg, H. Gornitzka, J. Escudié
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first step of the reaction leading to I is a double [2 + 2] tically able to react through its Ge=C and/or P=C double
cycloaddition between the Ge=C and C=O double bonds bonds, and also by the lone pair on the phosphorus atom.
to give transient dispiro compound II, with two four-mem-
Thus, we present here the reactivity of 1 towards four p-
bered oxagermacyclobutane rings, followed by its re- quinones (1,4-benzoquinone, 2,3,5,6-tetramethyl-1,4-benzo-
arrangement to give the final adduct with five-membered quinone, 1,4-naphthoquinone, and 9,10-anthraquinone)
rings (Scheme 2).[5]
and benzil. We also report the chemical behavior of 1
towards an o-quinone, phenanthrenequinone, which is
structurally close to benzil.
Results and Discussion
p-Quinones
1,4-Benzoquinone,
2,3,5,6-tetramethyl-1,4-benzoquin-
one, 1,4-naphthoquinone, and 9,10-anthraquinone were
added to solutions of 1 cooled to –80 °C in a 1:1 molar
ratio. The 31P NMR spectrum of the crude reaction mixture
showed in all cases the formation of only one product. Low-
field chemical shifts (328.2 to 336.3 ppm) indicated that the
P=C double bonds were not involved in the reaction.[12]
This is also confirmed by the low-field chemical shifts
(185.76–195.36 ppm) in the 13C NMR spectra with a large
1JCP (62.1 to 67.2 Hz) corresponding to the carbon atoms
doubly bonded to phosphorus. Signals between 86.75 and
93.50 ppm (2JCP from 32.7 to 41.6 Hz) correspond to an
oxygen-bound carbon atom. Similar chemical shifts were
observed in the 1-oxa-2-germacyclobutanes obtained from
1 and benzaldehyde, benzophenone, and fluorenone.[11a]
In the 13C NMR spectra, the presence of signals between
185.12 and 186.84 ppm prove that one carbonyl group is
Scheme 2. Postulated reaction of H2Ge=CH2 with 1,4-benzoquin-
one.
In the case of α-diketones such as benzil, a surprising
reaction occurs leading to the formation of compound III
according to an unexpected new type of epoxidation reac-
tion[6] (Scheme 3).
Scheme 3. Reaction of Mes2Ge=CR2 with benzil.
Heteroallenes E14=C=EЈ[7] (E14 = Si, Ge; EЈ = C,[8,9] still present and that the [2 + 2] cycloaddition between the
N,[10] P[11]), particularly those with two heavy group 14 and Ge=C and C=O bonds occurred with only one C=O double
15 elements, are still relatively rare and their chemical be- bond.
havior has been less explored.
All these data are in agreement with the formation of
After our studies on the reactivity of the germene Mes2- compounds 2–5 (Scheme 4).
1
Ge=CR2 towards quinones and α-diketones, we have been
The H NMR spectra display only one doublet for the
interested by a comparison with the reactivity of the phos- diastereotopic methyl groups of the p-iPr of Tip due to their
phagermaallene Tip(tBu)Ge=C=PMes*[11a] (1) towards the great distance to the chiral center and, as expected, two
same quinones and α-diketones. This heteroallene is theore- doublets for the methyl groups of the o-iPr groups. The
Scheme 4. Reaction of 1 with p-quinones to form 2–5.
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Reactivity of Quinones with a Phosphagermaallene
presence of only two doublets prove the free rotation of the acterized by 1H, 13C, and 31P NMR spectra, which give sim-
Tip group around the Ge–C(ipso) bond. Two singlets are ilar data as for 2, except for the absence of a C=O group,
observed for the o-tBu groups of Mes* due to its hindered and thus the formation of a double cycloadduct is con-
rotation on the NMR time scale.
cluded. The formation of only one isomer could be due to
The structure of 3 was unambiguously confirmed by an the difference in size between the involved groups.
X-ray study (Figure 1).
Thus, although only the Ge=C double bond is involved
in the reaction, the chemical behavior of 1 towards p-quin-
ones is completely different to that of the germene Mes2-
Ge=CR2. Whatever the quinone, similar reactions are ob-
served leading to stable spiro compounds with four-mem-
bered oxagermacyclobutane rings. These results confirm the
first step of the reaction postulated by calculations for ger-
mene and 1,4-benzoquinone.[5] Spiro compounds 2–5 do
not undergo rearrangement in solution and the formation
of five- or six-membered ring derivatives has not been ob-
served. Another striking difference is the possibility to
cleanly isolate a monocycloadduct, whereas a dicycloadduct
was exclusively observed in the case of germene, even when
using only one equivalent of the latter. However, a dicy-
cloadduct can also be obtained by using two equivalents of
1.
Figure 1. Structure of 3. Thermal ellipsoids are drawn at the 50%
probability level. All hydrogen atoms are omitted and Tip, tBu, and 9,10-Phenanthrenequinone and Benzil
Mes* have been simplified for clarity. Selected bond lengths [Å] and
angles [°]: Ge1–C1 2.008(2), Ge1–C12 1.998(2), Ge1–C16 1.986(2),
Ge1–O1 1.835(2), O1–C2 1.449(3), C1–C2 1.574(3), P1–C1
1.675(2), P1–C31 1.840(2), O1–Ge1–C1 73.9(1), C2–O1–Ge1
98.0(2), O1–C2–C1 99.8(2), C2–C1–Ge1 87.3(2).
To continue the comparison with Mes2Ge=CR2, we have
studied the reactivity towards 1 of the α-diketone benzil. We
have also extended our study to include the ortho-quinone
phenanthrenequinone. Benzil and phenanthrenequinone
The Ge–C bond lengths [1.986(2) to 2.008(2) Å] are at were added in equivalent molar ratios to solutions of 1 co-
the upper limit of the Ge–C bond-length range (1.94– oled to –80 °C to give the sole derivatives 7 and 8, respec-
1.98 Å)[13] similar to the Ge–O bond length of 1.835(2) Å tively, by a [2 + 4] cycloaddition between the Ge=C double
(generally 1.73–1.78 Å).[13] The P=C double bond presents bond and the O=C–C=O unit (Scheme 6). Their structures
a Z-configuration (Mes* and Ge on the same side), and were determined by mass spectrometry [the presence of mo-
the four-membered ring is nearly planar (Ge1–O1–C2–C1 lecular peaks at 832 (for 7) and 830 (for 8)], which proves
–8.59°, Ge1–C1–C2–O1 7.78°). Generally, 1-oxa-2-germa- the formation of 1:1 adducts, and by NMR spectroscopy.
cyclobutane rings are slightly more folded (for example 31P NMR spectra display signals at low field (7: 256.9 ppm
18.9°[11a] and 23°[14]). The geometry of the carbon atom and 8: 265.5 ppm) indicating the presence of a P=C double
of the C=P double bond is nearly planar (sum of angles: bond, and 13C NMR spectra show signals corresponding to
358.1°).
a O–C=C–O unit [7: C(OGe) 138.42 ppm, C(OCP)
3
The addition of two equivalents of 1 to 1,4-benzoquin- 142.23 ppm, JCP
=
8.6 Hz; 8: C(OGe) 138.42 ppm,
3
one or of one equivalent of 1 to derivative 2 yielded a sole C(OCP) 139.89 ppm, JCP = 7.8 Hz]. For the o-tBu groups,
derivative, as proved by 31P NMR analysis of the crude re- two singlets are observed in H NMR and two doublets in
1
action mixture. The product was identified as the double 13C NMR due to the hindered rotation of the Mes* group
cycloadduct 6 (Scheme 5). This dispiro derivative was char- on the NMR time scale. By contrast only one doublet is
Scheme 5. Synthesis of the cycloadduct 6.
Eur. J. Inorg. Chem. 2011, 281–288
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D. Ghereg, H. Gornitzka, J. Escudié
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observed for the diastereotopic methyl groups of the p-iPr the six-membered Ge1–O1–C2–C9–O2–C1 ring is dis-
groups due to their distance from the chiral center. All these torted; the Ge atom is close to the O1–C2–C9–O2 plane
data are in agreement with [2 + 4] cycloadditions between (0.267 Å), while the C1 atom is at 0.834 Å out of this plane.
the Ge=C double bonds and the O=C–C=O units.
The phenyl groups are not coplanar with the O–C=C–O
plane showing twists of 31.78° (Ph of COC) and 42.68° (Ph
of COGe) preventing conjugation through the C=C double
bond. Whereas in 8, the P=C double bond is in the plane
of the phenanthrenic unit, in fact, it is nearly perpendicular
to the O–C=C–O plane in 7 (P1–C1–O2–C9 97.91°).
Scheme 6. Reaction of 1 with 9,10-phenanthrenequinone and ben-
zil.
The structures of 7 and 8 were unambiguously deter-
mined by an X-ray study, see Figures 2 (for 7) and 3 (for
8). The C=C double bond lengths [for 7: 1.345(4) Å; for 8:
1.353(3) Å] in the (O)C=C(O) unit, prove the formation of
the six-membered Ge–O–C=C–O–C rings. 7 and 8 present
some different characteristics: surprisingly, the configura-
tions of the P=C double bonds are different (Z for 7 and E
for 8) without satisfactory explanation. In 8, the four cycles
of the phenanthrenic unit and of the dioxagermacyclohex-
ene are in the same plane, with the sole exception of the
germanium atom situated 0.432 Å out of the plane. In 7,
Figure 3. Structure of 8. Thermal ellipsoids are drawn at the 50%
probability level. Disorders of Tip and a tBu group from Mes*
and all hydrogen atoms are omitted. Tip, tBu and Mes* have been
simplified for clarity. Selected bond lengths [Å] and angles [°]: Ge1–
C1 1.971(2), Ge1–C16 1.990(2), Ge1–C20 1.988(2), Ge1–O1
1.821(2), O1–C2 1.357(2), C2–C3 1.353(3), O2–C3 1.382(2), O2–
C1 1.372(2), C2–C15 1.448(3), C10–C15 1.414(3), C9–C10
1.450(3), C4–C9 1.415(3), C3–C4 1.439(3), P1–C1 1.686(2), P1–
C35 1.861(2), O1–Ge1–C1 96.79(7), C2–O1–Ge1 122.8(2), C3–C2–
O1 124.8(2), C2–C3–O2 125.7(2), C1–O2–C3 126.2(2), O2–C1–Ge1
118.0(2).
We must note that the reactions of 1 and germene Mes2-
Ge=CR2 towards benzil are completely different as with the
germene an epoxidation was observed (Scheme 3 and
Scheme 7). The first steps of the reaction are probably the
same, involving a nucleophilic attack of one oxygen atom
on the germanium. In the case of 7, the ring closure leading
to the six-membered ring could be faster than the epoxid-
ation, whereas with the germene, due to good stabilization
of the anionic charge on the fluorenyl group, the epoxid-
ation is favored.
Figure 2. Structure of 7. Thermal ellipsoids are drawn at the 50%
probability level. A disorder of a tBu group from Mes*, noncoordi-
nating Me2CO, and all hydrogen atoms are omitted. Tip, tBu, and
Mes* have been simplified for clarity. Selected bond lengths [Å]
and angles [°]: Ge1–C1 1.970(2), C1–O2 1.436(3), O2–C9 1.418(3),
C2–C9 1.345(4), O1–C2 1.375(3), Ge1–O1 1.830(2), P1–C1
1.686(2), P1–C35 1.854(3), O1–Ge1–C1 90.0(1), C2–O1–Ge1
120.4(2), C9–C2–O1 124.5(2), C2–C9–O2 121.4(2), C9–O2–C1 Scheme 7. Different reactivities of Mes2Ge=CR2 and 1 towards
114.9(2), O2–C1–Ge1 100.8(2).
benzil.
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Reactivity of Quinones with a Phosphagermaallene
4
4
CHMeMeЈ), 33.38 (d, JCP = 8.4 Hz) and 34.45 (d, JCP = 5.4 Hz,
o-CMe3 of Mes*), 34.13 (p-CHMeMeЈ), 35.05 (p-CMe3 of Mes*),
35.96 (GeCMe3), 38.21 and 38.98 (o-CMe3 of Mes*), 86.75 (d, 2JCP
= 41.6 Hz, C-O), 120.85, 122.23, 122.36 and 123.02 (m-CH of Tip.
The reactivity of 1 towards benzil is similar to that ob-
served for silenes ϾSi=CϽ,[15] phosphagermene –P=GeϽ,[16]
and germavinylidene ϾC=Ge:[17] with this diketone.
4
4
m-CH of Mes*), 122.85 (d, JCP = 2.9 Hz) and 125.48 (d, JCP
3.0 Hz, CHC=O), 130.18 (ipso-C of Tip), 135.15 (d, JCP
68.38 Hz, ipso-C of Mes*), 150.00 (d, JCP = 7.3 Hz) and 153.33
(d, JCP = 7.3 Hz, CHC-O), 150.56 and 151.08 (p-C of Mes* and
p-C of Tip), 152.81, 153.28, 153.44 (d, JCP = 8.7 Hz) and 155.69
(o-C of Mes* and o-C of Tip), 185.76 (d, JCP = 64.15 Hz, C=P),
=
=
1
3
Conclusions
3
2
Although 1 reacts with o- and p-quinones and α-dike-
tones exclusively through the Ge=C double bond, its chemi-
cal behavior is completely different to that of the germene
Mes2Ge=CR2. This difference is due, among other factors,
to the presence of the cumulated P=C double bond and a
less polarized Ge=C double bond in 1. Regioselective and
nearly quantitative reactions are observed, which prove the
high synthetic potential of this heteroallene in organometal-
lic and heterocyclic chemistry.
1
186.84 (C=O) ppm. 31P NMR (121.51 MHz): δ = 336.3 ppm. MS:
m/z (%) = 731 (5) [M + 1], 674 (5) [M – tBu + 1], 509 (10) [Tip(tBu)-
Ge=C=PMes* – 2tBu + 1], 276 (5) [TipGe – 1], 57 (100) [tBu].
C44H65GeO2P (729.56): calcd. C 72.44, H 8.98; found C 72.62, H
9.05.
3: Yield 0.60 g, 77%, m.p. 145 °C. 1H NMR (300.13 MHz, CDCl3):
δ = 0.45, 0.94, 1.24 and 1.28 (4d, JHH = 6.6 Hz, 4ϫ3 H, o-
CHMeMeЈ), 1.18 (s, 9 H, Ge-CMe3), 1.20 (d, JHH = 6.6 Hz, 6 H,
3
3
p-CHMe2), 1.33 (s, 9 H, p-CMe3 of Mes*), 1.34 and 1.43 (2s, 2ϫ9
H, o-CMe3 of Mes*), 1.83 (s, 6 H, MeC=CMe), 1.97 and 2.34 (2s,
3
4ϫ3 H, MeC=CMe), 2.36 and 3.00 (2sept, JHH = 6.6 Hz, 2ϫ1
Experimental Section
3
H, o-CHMeMeЈ), 2.81 (sept, JHH = 6.6 Hz, 1 H, p-CHMe2), 6.84
General Information: All experiments were carried out in flame-
dried glassware under an argon atmosphere using high vacuum line
techniques. Solvents were freshly dried using an SPS-5MB system.
NMR spectra were recorded (with CDCl3 as solvent) with a Bruker
Avance 300 spectrometer at the following frequencies: 1H,
300.13 MHz (reference TMS); 13C, 75.47 MHz (reference TMS);
31P, 121.51 MHz (reference H3PO4). 1H and 13C{1H} NMR assign-
and 7.00 (2s, 2ϫ1 H, m-CH of Tip), 7.33 and 7.37 (2s, 2ϫ1 H, m-
CH of Mes*) ppm. 13C NMR (75.47 MHz): δ = 11.26, 11.51, 18.40
and 18.57 (MeC=CMe), 23.76, 25.16, 25.54 and 26.30 (p-CHMe2,
o-CHMeMeЈ), 30.00 (Ge-CMe3), 31.30 (p-CMe3 of Mes*), 33.45,
33.61 and 33.99 (p-CHMe2, o-CHMeMeЈ), 33.79 (d, 4JCP = 8.8 Hz,
o-CMe3 of Mes*), 34.79 (p-CMe3 of Mes*), 35.05 (Ge-CMe3),
4
35.66 (d, JCP = 6.2 Hz, o-CMe3 of Mes*), 38.39 and 39.66 (o-
1
ments were confirmed by H COSY, HSQC (1H-13C), and HMBC
CMe3 of Mes*), 93.50 (d, 2JCP = 39.0 Hz, C-O), 121.02 and 122.43
(1H-13C) experiments. Melting points were determined with a Wild
Leitz-Biomed apparatus. Mass spectra were obtained with a Hew-
lett–Packard 5989A spectrometer by EI at 70 eV and with a Ner-
mag R10-10 spectrometer by CI. Elemental analyses were per-
formed by the Service de Microanalyse de l’Ecole de Chimie de
Toulouse.
(m-CH of Tip), 121.52 and 122.95 (m-CH of Mes*), 127.22 (d, 4JCP
4
1
= 2.5 Hz) and 129.13 (d, JCP = 4.0 Hz, C-C=O), 133.69 (d, JCP
= 69.9 Hz, ipso-C of Mes*), 134.87 (ipso-C of Tip), 149.75 (p-C of
Mes*), 150.16 (p-C of Tip), 151.30 and 153.20 (o-C of Tip), 153.35
2
(d, JCP = 5.9 Hz) and 154.17 (o-C of Mes*), 155.35 and 157.72
(2d, JCP = 7.7 Hz, C-C-O), 185.89 (C=O), 188.48 (d, JCP
3
1
=
67.2 Hz, C=P) ppm. 31P NMR (121.51 MHz): δ = 333.4 ppm. MS:
m/z (%) = 786 (5) [M], 621 (5) [Tip(tBu)Ge=C=PMes* – 1], 509
(10) [Tip(tBu)Ge=C=PMes* – 2tBu + 1], 377 (10) [Tip(tBu)Ge=C=
PMes* – Mes*], 276 (25) [TipGe – 1], 164 (20) [quinone], 57 (100)
[tBu]. C48H73GeO2P (785.67): calcd. C 73.38, H 9.37; found C
73.45, H 9.29.
Synthesis of 1: The phosphagermaallene 1 was synthesized as de-
scribed previously[11a] by addition of one equivalent of tert-butyl-
lithium to an Et2O solution of phosphagermapropene Tip(tBu)(F)-
Ge–C(Cl)=PMes* cooled to –80 °C. As the reaction was quantita-
tive according to 31P NMR spectra, crude brown-red solutions of
1, including LiF, were used in all cases.
4: Yield 0.53 g, 68%, m.p. 174 °C. 1H NMR (300.13 MHz, CDCl3):
Reaction of p-Quinones with 1: To a solution of 1 (1 mmol) in Et2O
(20 mL) cooled to –80 °C was added one equivalent of p-quinone
(1,4-benzoquinone, 2,3,5,6-tetramethyl-1,4-benzoquinone, 1,4-
naphthoquinone, and 9,10-anthraquinone). After warming to room
temperature and stirring for 3 h, a yellow coloration appeared. Sol-
vents were removed in vacuo and replaced by pentane (50 mL). LiF
was removed by filtration. After concentration to 5 mL, cooling to
–20 °C afforded crystals of derivatives 2, 3, 4, and 5.
3
δ = 0.84, 0.90, 1.13 and 1.27 (4d, JHH = 6.6 Hz, 4ϫ3 H, o-
3
CHMeMeЈ), 1.24 (d, JHH = 6.6 Hz, 6 H, p-CHMeMeЈ), 1.28 (s, 9
H, GeCMe3), 1.32 and 1.42 (2s, 2ϫ9 H, o-CMe3 of Mes*), 1.33
3
(p-CMe3 of Mes*), 1.96 and 3.38 (2sept, JHH = 6.6 Hz, 2ϫ1 H,
3
o-CHMeMeЈ), 2.86 (sept, JHH = 6.6 Hz, 1 H, p-CHMeMeЈ), 6.10
3
4
(d, JHH = 10.2 Hz, 1 H, CHC=O), 6.88 and 7.08 (2d, JHH
=
1.5 Hz, 2ϫ1 H, m-CH of Tip), 6.96 (d, 3JHH = 10.2 Hz, 1 H, CHC-
O), 7.29 and 7.35 (2s, 2ϫ1 H, m-CH of Mes*), 7.44 and 7.65 (2dt,
= 7.5, JHH = 1.5 Hz, 2ϫ1 H, arom. H), 8.12 (d, JHH = 7.5 Hz,
2 H, arom. H) ppm. 13C NMR (75.47 MHz): δ = 23.73 and 23.84
(p-CHMeMeЈ), 24.83, 24.99, 25.59 and 27.41 (o-CHMeMeЈ), 28.55
4
3
2: Yield 0.57 g, 78%, m.p. 123 °C. 1H NMR (300.13 MHz, CDCl3):
3
δ = 0.37, 0.94, 1.12 and 1.29 (4d, JHH = 6.6 Hz, 4ϫ3 H, o-
3
CHMeMeЈ), 1.22 (d, JHH = 6.6 Hz, 6 H, p-CHMeMeЈ), 1.26 (s, 9
H, GeCMe3), 1.30 (s, 9 H, p-CMe3 of Mes*), 1.32 and 1.56 (2s,
(GeCMe3), 31.37 (p-CMe3 of Mes*), 32.74 and 36.45 (o-
3
4
2ϫ9 H, o-CMe3 of Mes*), 1.88 and 3.58 (2sept, JHH = 6.6 Hz, CHMeMeЈ), 34.02 (p-CHMeMeЈ), 34.56 (d, JCP = 8.2 Hz) and
3
4
2ϫ1 H, o-CHMeMeЈ), 2.82 (sept, JHH = 6.6 Hz, 1 H, p-
35.14 (d, JCP = 5.7 Hz, o-CMe3 of Mes*), 34.88 (p-CMe3 of
4
CHMeMeЈ), 6.03 and 6.21 (3JHH = 10.2, JHH = 1.8 Hz, 2ϫ1 H,
Mes*), 35.52 (GeCMe3), 38.34 and 39.12 (o-CMe3 of Mes*), 87.77
CHC=O), 6.79 and 7.04 (2s, 2ϫ1 H, m-CH of Tip), 6.99 and 7.38
(d, 2JCP = 38.6 Hz, C-O), 120.73 and 123.32 (m-CH of Tip), 121.03
4
(3JHH = 10.2, JHH = 3.0 Hz, 2ϫ1 H, CHC-O), 7.34 and 7.42 (2s,
and 122.42 (m-CH of Mes*), 122.16 (CHC=O), 125.90, 127.86,
2ϫ1 H, m-CH of Mes*) ppm. 13C NMR (75.47 MHz): δ = 23.76
128.97 and 132.63 (arom. CH), 130.47 and 148.48 (d, JCP
=
3
(p-CHMeMeЈ), 23.87, 24.78, 25.61 and 27.27 (o-CHMeMeЈ), 27.91 7.5 Hz, arom. C), 131.98 (ipso-C of Tip), 135.27 (d, 1JCP = 65.5 Hz,
(GeCMe3), 31.31 (p-CMe3 of Mes*), 31.82 and 37.92 (o- ipso-C of Mes*), 149.83 (p-C of Tip), 150.77 (p-C of Mes*), 152.60
Eur. J. Inorg. Chem. 2011, 281–288
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
285

D. Ghereg, H. Gornitzka, J. Escudié
FULL PAPER
2
3
and 155.43 (o-C of Tip), 153.21 (d, JCP = 5.4 Hz) and 153.73 (o-
121.95 (m-CH of Mes*), 129.66 (d, JCP = 7.8 Hz) and 134.87 (d,
3
1
C of Mes*), 154.30 (d, JCP = 8.5 Hz, CHC-O), 185.55 (C=O),
3JCP = 8.5 Hz, CH-C-O), 131.72 (ipso-C of Tip), 138.22 (d, JCP
=
1
192.91 (d, JCP = 63.7 Hz, C=P) ppm. 31P NMR (121.51 MHz): δ
71.7 Hz, ipso-C of Mes*), 149.29 (p-C of Mes*), 150.03 (p-C of
2
= 328.2 ppm. MS: m/z (%) = 781 (5) [M + 1], 724 (10) [M – tBu
+ 1], 377 (15) [Tip(tBu)Ge=C=PMes* – Mes*], 275 (20) [TipGe –
2], 131 (10) [tBuGe], 57 (100) [tBu]. C48H67GeO2P (779.62): calcd.
C 73.95, H 8.66; found C 73.88, H 8.71.
Tip), 152.78 and 156.18 (o-C of Tip), 152.89 and 153.17 (d, JCP =
1
6.7 Hz), 195.80 (d, JCP
=
66.7 Hz, C=P) ppm. 31P NMR
(121.51 MHz): δ = 323.5 ppm. C82H126Ge2O2P2 (1351.02): calcd. C
72.90, H 9.40; found C 73.01, H 9.35.
5: Yield 0.59 g, 71%, m.p. 183 °C. 1H NMR (300.13 MHz, CDCl3):
δ = 0.66, 1.04, 1.28 and 1.39 (4d, JHH = 6.6 Hz, 4ϫ3 H, o- (10 mL) was slowly added to a solution of 1 cooled to –80 °C. The
Reaction of Benzil with 1: A solution of benzil (1 mmol) in Et2O
3
CHMeMeЈ), 0.85 and 1.13 (2s, 2ϫ9 H, o-CMe3 of Mes*), 1.22 (s,
reaction mixture, warmed to room temperature and stirred over-
night, became yellow. Solvents were removed in vacuo and replaced
by pentane (30 mL). LiF was removed by filtration. Crystallization
3
9 H, GeCMe3), 1.26 (s, 9 H, p-CMe3 of Mes*), 1.28 (d, JHH
=
3
6.6 Hz, 6 H, p-CHMeMeЈ), 1.97 and 3.16 (2sept, JHH = 6.6 Hz,
3
1
2ϫ1 H, o-CHMeMeЈ), 2.91 (sept, JHH = 6.6 Hz, 1 H, p-
from pentane at –20 °C afforded 7 (0.70 g, 84%, m.p. 201 °C). H
4
CHMeMeЈ), 6.92 and 7.16 (2d, JHH = 1.8 Hz, 2ϫ1 H, m-CH of
NMR (300.13 MHz, CDCl3): δ = 0.69 (s, 9 H, GeCMe3), 1.22 (d,
3
3
Tip), 7.00, 7.21, 7.48 and 7.69 (4ddd, JHH = 7.8, 3JHH = 7.2, 4JHH
3JHH = 6.9 Hz, 6 H, p-CHMe2), 1.24 and 1.26 (2d, JHH = 6.9 Hz,
= 1.5 Hz, 4ϫ1 H, arom. H), 7.16 and 7.22 (2s, 2ϫ1 H, m-CH of
Mes*), 7.52, 8.23, 8.30 and 8.45 (4dd, JHH = 7.8, JHH = 1.5 Hz,
2ϫ6 H, o-CHMeMeЈ), 1.28 (p-CMe3 of Mes*), 1.36 and 1.64 (2s,
2ϫ9 H, o-CMe3 of Mes*), 2.81 (sept, JHH = 6.9 Hz, 1 H, p-
3
4
3
4ϫ1 H, arom. H) ppm. 13C NMR (75.47 MHz): δ = 23.90 and CHMe2), 3.29 (br., 2 H, o-CHMeMeЈ), 6.97 (s, 2 H, m-CH of Tip),
23.95 (p-CHMeMeЈ), 24.53, 25.67, 25.79 and 27.46 (o-CHMeMeЈ), 7.10–7.19 (m, 6 H, CH arom. of Ph), 7.33 and 7.40 (2s, 2ϫ1 H,
29.05 (GeCMe3), 31.36 (p-CMe3 of Mes*), 33.75 (GeCMe3), 33.85
m-CH of Mes*), 7.33–7.36 (m, 2 H, CH arom. of Ph), 7.53 (d, 3JHH
4
4
(d, JCP = 7.2 Hz) and 34.99 (d, JCP = 6.4 Hz, o-CMe3 of Mes*), = 7.5 Hz, 2 H, CH arom. of Ph) ppm. 13C NMR (75.47 MHz):
34.19 (p-CHMeMeЈ), 34.39 and 35.25 (o-CHMeMeЈ), 34.75 (p- δ = 23.72 (p-CHMe2), 24.92 and 26.23 (br., o-CHMeMeЈ), 27.62
CMe3 of Mes*), 37.87 and 39.23 (o-CMe3 of Mes*), 91.01 (d, 2JCP
= 32.7 Hz, C-O), 120.31 and 122.23 (m-CH of Mes*), 120.82 and
122.90 (m-CH of Tip), 125.74, 126.28, 126.49, 126.58, 127.23,
(GeCMe3), 29.14 (GeCMe3), 31.35 (p-CMe3 of Mes*), 33.87 (p-
4
CHMeMeЈ), 33.90 (o-CHMeMeЈ), 34.11 (d, JCP = 8.7 Hz) and
4
34.45 (d, JCP = 6.2 Hz, o-CMe3 of Mes*), 34.79 (p-CMe3 of
127.70, 132.24 and 132.25 (arom. CH), 129.64 (d, JCP = 2.7 Hz), Mes*), 38.77 and 38.82 (o-CMe3 of Mes*), 122.23 (m-CH of Tip),
130.94 (d, JCP = 5.6 Hz), 149.54 (d, JCP = 2.5 Hz) and 150.28 (d,
JCP = 7.4 Hz, arom. C), 134.03 (d, 1JCP = 63.3 Hz, ipso-C of Mes*),
134.52 (ipso-C of Tip), 149.52 (p-C of Mes*), 150.69 (p-C of Tip),
122.25 and 122.62 (m-CH of Mes*), 126.53, 126.68, 126.92 (2CH),
127.65 (2CH), 129.73 (2CH), 129.86 and 129.89 (arom. CH of Ph),
129.09, 129.34 (ipso-C of Tip, ipso-C of Mes*), 136.54, 137.70 and
2
3
152.31 and 154.49 (o-C of Tip), 153.59 (d, JCP = 3.2 Hz) and
138.42 (COGe and 2 ipso-C of Ph), 142.23 (d, JCP = 8.6 Hz,
1
153.75 (o-C of Mes*), 185.12 (C=O), 195.36 (d, JCP = 62.1 Hz,
COCP), 149.45 (p-C of Tip), 149.98 (p-C of Mes*), 154.54 (br., 2
C=P) ppm. 31P NMR (121.51 MHz): δ = 334.9 ppm. MS: m/z (%)
= 831 (4) [M + 1], 774 (5) [M – tBu + 1], 566 (15) [Tip(tBu)-
Ge=C=PMes* – tBu + 1], 510 (30) [Tip(tBu)Ge=C=PMes* – 2tBu
+ 2], 377 (10) [Tip(tBu)Ge=C=PMes* – Mes*], 275 (15) [TipGe –
2], 208 (50) [1,4-anthraquinone], 131 (5) [tBuGe], 57 (100) [tBu].
C52H69GeO2P (829.68): calcd. C 75.28, H 8.38; found C 75.36, H
8.27.
o-C of Tip), 155.43 and 156.21 (d, JCP = 3.3 Hz, o-C of Mes*),
2
1
201.70 (d, JCP = 58.9 Hz, C=P) ppm. 31P NMR (121.51 MHz): δ
= 256.9 ppm. MS: m/z (%) = 832 (5) [M], 775 (10) [M – tBu], 565
(20) [Tip(tBu)Ge=C=PMes*
–
tBu], 377 (20) [Tip(tBu)-
Ge=C=PMes* – Mes*], 333 (5) [Tip(tBu)Ge – 1], 275 (50) [TipGe –
2], 203 (10) [Tip], 77 (70) [Ph], 57 (100) [tBu]. C52H71GeO2P
(831.72): calcd. C 75.10, H 8.60; found C 75.12, H 8.56.
Reaction of 1,4-Benzoquinone with 1 in a 1:2 Ratio: The reaction is Reaction of 9,10-Phenanthrenequinone with 1: A suspension of 9,10-
made exactly in the same conditions as described above for the 1:1
ratio reaction. Compound (1 mmol) and p-benzoquinone
phenanthrenequinone (1 mmol) in toluene (10 mL) was slowly
added to a solution of 1 (1 mmol) in Et2O (10 mL) cooled to
1
(0.5 mmol) were reacted together to afford 6 (1.00 g; 74%; m.p. –78 °C. After warming to room temperature, the yellow reaction
197 °C). Compound 6 can be obtained by addition of one equiva-
lent of 1 in Et2O solution to the spiro compound 2 (0.51 g,
mixture was stirred overnight. LiF was removed by filtration, and
the solvents removed in vacuo and replaced with pentane (20 mL).
0.70 mmol) cooled to –50 °C. After warming to room temperature, Crystallization from cold pentane afforded 8 (0.74 g, 89%, m.p.
the solvent was removed under reduced pressure and replaced by
pentane (20 mL). LiF was removed by filtration, and cooling to
226 °C). 1H NMR (300.13 MHz, CDCl3): δ = 0.79 and 1.29 (2d,
3JHH = 6.6 Hz, 2ϫ6 H, o-CHMeMeЈ), 0.83 (s, 9 H, GeCMe3), 1.14
3
–20 °C afforded
(300.13 MHz, CDCl3): δ = 0.39, 0.93, 1.03 and 1.29 (4d, JHH
6
(0.76 g, 81%) in high purity. 1H NMR
and 1.66 (2s, 2ϫ9 H, o-CMe3 of Mes*), 1.16 (d, JHH = 6.9 Hz, 6
3
3
=
H, p-CHMeMeЈ), 2.75 (sept, JHH = 6.6 Hz, 1 H, p-CHMeMeЈ),
6.6 Hz, 4ϫ6 H, o-CHMeMeЈ), 1.19 (s, 18 H, Ge-CMe3), 1.20 and 3.24 (br. s, 2 H, o-CHMeMeЈ), 6.88 (s, 2 H, m-CH of Tip), 7.36
3
3
4
1.21 (2d, JHH = 6.6 Hz, 2ϫ6 H, p-CHMeMeЈ), 1.33 (s, 18 H, p-
and 7.42 (2s, 2ϫ1 H, m-CH of Mes*), 7.46 (dt, JHH = 7.5, JHH
CMe3 of Mes*), 1.36 and 1.59 (2s, 2ϫ18 H, o-CMe3 of Mes*),
= 1.2 Hz, 1 H), 7.53–7.59 (m, 3 H), 8.30–8.33 (m, 1 H), 8.40 and
3
3
1.98 and 3.84 (2sept, JHH = 6.6 Hz, 2ϫ2 H, o-CHMeMeЈ), 2.81
8.56 (2d, JHH = 8.1 Hz, 2 H), 8.54–8.57 (m, 1 H, arom. CH of
(sept, 3JHH = 6.6 Hz, 2 H, p-CHMeMeЈ), 6.13 and 6.30 (2dd, 3JHH
phenanthrene unit) ppm. 13C NMR (75.47 MHz): δ = 23.60 and
4
4
= 9.9, JHH = 2.1 Hz, 2ϫ2 H, CH-CO), 6.76 and 7.00 (2d, JHH 23.71 (p-CHMeMeЈ), 24.73 and 25.94 (o-CHMeMeЈ), 27.92
= 1.5 Hz, 2ϫ2 H, m-CH of Tip), 7.33 and 7.40 (2s, 2ϫ2 H, m-
(GeCMe3), 29.29 (GeCMe3), 31.39 (p-CMe3 of Mes*), 33.61 (p-
4
CH of Mes*) ppm. 13C NMR (75.47 MHz): δ = 23.76 and 23.79
CHMeMeЈ), 33.77 (d, JCP = 8.7 Hz) and 34.23 (4JCP = 8.7 Hz, o-
(p-CHMeMeЈ), 23.91, 24.88, 25.69 and 27.39 (o-CHMeMeЈ), 28.25 CMe3 of Mes*), 34.45 (2 o-CHMeMeЈ), 34.89 (p-CMe3 of Mes*),
(Ge-CMe3), 31.18 and 37.23 (o-CHMeMeЈ), 31.37 (p-CMe3 of 38.64 (2 o-CMe3 of Mes*), 121.56, 122.05, 122.26, 122.67, 123.50,
4
4
Mes*), 33.35 (d, JCP = 8.1 Hz) and 34.25 (d, JCP = 5.6 Hz, o-
124.72, 125.81 and 126.27 (arom. CH), 127.70, 127.72, 128.34 and
1
CMe3 of Mes*), 34.05 (p-CHMeMeЈ), 34.74 (Ge-CMe3), 34.95 (p- 129.83 (arom. C), 129.17 (ipso-C of Tip), 129.58 (d, JCP
=
=
CMe3 of Mes*), 38.28 and 38.92 (o-CMe3 of Mes*), 86.25 (d, 2JCP
= 40.8 Hz, C-O), 120.33 and 122.55 (m-CH of Tip), 121.73 and
62.43 Hz, ipso-C of Mes*), 138.42 (COGe), 139.89 (d, JCP
3
7.8 Hz, COCP), 149.65 and 150.24 (p-C of Tip and p-C of Mes*),
286
www.eurjic.org
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2011, 281–288

Reactivity of Quinones with a Phosphagermaallene
2
C. Couret, H. Ranaivonjatovo, J. Satgé, Coord. Chem. Rev.
1994, 130, 427–480; d) N. Tokitoh, R. Okazaki, in: The Chem-
istry of Organic Germanium, Tin and Lead Compounds, vol. 2
(Eds.: Z. Rappoport), Wiley & Sons, New York, 2002, chapter
13, p. 843–901.
D. Ghereg, S. Ech-Cherif El Kettani, M. Lazraq, H. Ranaivon-
jatovo, W. W. Schoeller, J. Escudié, H. Gornitzka, Chem. Com-
mun. 2009, 4821–4823.
154.72 (br., o-C of Tip), 155.41 and 156.27 (d, JCP = 3.1 Hz, o-C
of Mes*), 202.61 (d, JCP = 60.0 Hz, C=P) ppm. 31P NMR
(121.51 MHz): δ = 265.5 ppm. MS: m/z (%) = 830 (10) [M], 773
(4) [M – tBu], 715 (2) [M – 2tBu – 1], 621 (2) [9,10-phenanthrene-
1
quinone
– 1], 585 (4) [M – Mes*], 565 (15) [Tip(tBu)-
[3]
Ge=C=PMes* – tBu], 542 (10) [M – Mes*PC], 377 (10) [Tip(tBu)-
Ge=C=PMes* – Mes*], 333 (5) [Tip(tBu)Ge – 1], 275 (40) [TipGe –
2], 233 (20) [TipGe – iPr], 131 (5) [tBuGe], 57 (100) [tBu].
C52H69GeO2P (829.68): calcd. C 75.28, H 8.38; found C 75.33, H
8.41.
[4]
[5]
D. Ghereg, H. Gornitzka, H. Ranaivonjatovo, J. Escudié, Dal-
ton Trans. 2010, 39, 2016–2022.
D. Ghereg, E. André, S. Ech-Cherif El Kettani, N. Saffon, M.
Lazraq, H. Ranaivonjatovo, H. Gornitzka, K. Miqueu, J.-M.
Sotiropoulos, J. Escudié, Organometallics 2010, 29, 4849–4857.
S. Ech-Cherif El Kettani, M. Lazraq, F. Ouhsaine, H. Gor-
nitzka, H. Ranaivonjatovo, J. Escudié, Org. Biomol. Chem.
2008, 6, 4064–4066.
For reviews on heteroallenes, see: a) J. Escudié, H. Ranaivonja-
tovo, L. Rigon, Chem. Rev. 2000, 100, 3639–3696; b) B. Eichler,
R. West, Adv. Organomet. Chem. 2001, 46, 1–46; c) J. Escudié,
H. Ranaivonjatovo, Organometallics 2007, 26, 1542–1559; d)
R. Appel, in: Multiple Bonds and Low Coordination in Phospho-
rus Chemistry (Eds.: M. Regitz, O. J. Scherer) Thieme, Stutt-
gart, 1990, pp. 157–219; e) M. Yoshifuji, J. Chem. Soc., Dalton
Trans. 1998, 3343–3349.
For stable ϾSi=C=CϽ, see: a) G. Miracle, J. L. Ball, D. R.
Powell, R. West, J. Am. Chem. Soc. 1993, 115, 11598–11599;
b) M. Trommer, G. E. Miracle, B. E. Eichler, D. R. Powell, R.
West, Organometallics 1997, 16, 5737–5747; c) B. E. Eichler,
G. E. Miracle, D. R. Powell, R. West, Main Group Met. Chem.
1999, 22, 147–162; d) M. Ichinohe, T. Tanaka, A. Sekiguchi,
Chem. Lett. 2001, 1074–1075; e) S. Spirk, F. Belaj, J. H. Alber-
ing, R. Pietschnig, Organometallics 2010, 29, 2981–2986.
For stable ϾGe=C=CϽ, see: a) B. E. Eichler, D. R. Powell, R.
West, Organometallics 1998, 17, 2147–2148; B. E. Eichler, D. R.
Powell, R. West, Organometallics 1999, 18, 540–545; b) K. Ki-
shikawa, N. Tokitoh, R. Okazaki, Organometallics 1997, 16,
5127–5129; c) N. Tokitoh, K. Kishikawa, R. Okazaki, Chem.
X-ray Structure Determinations for 3, 7, and 8: All data were col-
lected at low temperatures using an oil-coated shock-cooled crystal
with a Bruker AXS APEX II diffractometer with Mo-Kα radiation
[6]
[7]
(λ = 0.71073 Å). The structures were solved by direct methods[18]
,
and all non-hydrogen atoms were refined anisotropically using the
least-squares method on F2.[19]
3: C48H73GeO2P, M = 785.62, crystal size 0.4ϫ0.4ϫ0.1 mm3, mo-
noclinic, space group P21/n, a = 13.143(1) Å, b = 9.929(1) Å, c =
34.217(2) Å, β = 93.33(1)°, V = 4457.6(2) Å3, Z = 4, T = 180(2) K,
67191 reflections collected, 10898 unique reflections (Rint
=
0.0687), R1 = 0.0470, wR2 = 0.1052 [IϾ2σ(I)], R1 = 0.0731, wR2
= 0.1154 (all data), residual electron density: 0.803 eÅ–3.
[8]
7·CH3COCH3: C55H77GeO3P,
0.5ϫ0.4ϫ0.3 mm3, orthorhombic, space group Pna21,
17.3423(5) Å, 21.8401(6) Å, 13.2244(3) Å,
M
=
889.73, crystal size:
a
V
=
=
b
=
c
=
5008.8(2) Å3, Z = 4, T = 110(2) K, 46590 reflections collected,
10092 unique reflections (Rint = 0.0377), R1 = 0.0349, wR2 =
0.0800 [IϾ2σ(I)], R1 = 0.0471, wR2 = 0.0857 (all data), residual
electron density = 0.749 eÅ–3.
[9]
8: C52H69GeO2P, M = 829.63, crystal size: 0.4ϫ0.3ϫ0.3 mm3, mo-
noclinic, space group P21/n, a = 9.0123(3) Å, b = 28.0792(10) Å, c
= 18.6998(7) Å, β = 101.840(2)°, V = 4631.5(3) Å3, Z = 4, T =
180(2) K, 48827 reflections collected, 11378 unique reflections (Rint
= 0.0552), R1 = 0.0402, wR2 = 0.0911 [IϾ2σ(I)], R1 = 0.0611,
wR2 = 0.0994 (all data), residual electron density: 0.373 eÅ–3.
Lett. 1998, 811–812.
ϾSi=C=N–
[10a–10c]
and ϾSn=C=N–[10d] are generally better
[10]
considered as silylenes (or stannylenes) isocyanide complexes
than as azasilaallenes (or azastannaallenes), see: a) N. Takeda,
H. Suzuki, N. Tokitoh, R. Okazaki, S. Nagase, J. Am. Chem.
Soc. 1997, 119, 1456–1457; b) N. Takeda, T. Kajiwara, H. Su-
zuki, R. Okazaki, N. Tokitoh, Chem. Eur. J. 2003, 9, 3530–
3543; c) T. Abe, T. Iwamoto, C. Kabuto, M. Kira, J. Am. Chem.
Soc. 2006, 128, 4228–4229; d) H. Grützmacher, S. Freitag, R.
Herbst-Irmer, G. M. Sheldrick, Angew. Chem. Int. Ed. Engl.
1992, 31, 437–438.
CCDC-783545 (for 3), -783546 (for 7·CH3COCH3) and -783547
(for 8) contain the supplementary crystallographic data for this pa-
per. These data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_
request/cif.
Only one ϾGe=C=P– derivative[11a] is stable at room tempera-
ture, see: a) Y. El Harouch, H. Gornitzka, H. Ranaivonjatovo,
J. Escudié, J. Organomet. Chem. 2002, 643–644, 202–208; tran-
sient ϾSi=C=P–[11b] and ϾGe=C=P–[11c] have also been re-
ported, see: b) L. Rigon, H. Ranaivonjatovo, J. Escudié, A.
Dubourg, J.-P. Declercq, Chem. Eur. J. 1999, 5, 774–781; c)
H. Ramdane, H. Ranaivonjatovo, J. Escudié, S. Mathieu, N.
Knouzi, Organometallics 1996, 15, 3070–3075.
[11]
Acknowledgments
We are grateful to the Agence Nationale pour la Recherche (con-
tract ANR-08-BLAN-0105-01) and PhoSciNet (CM0802) for fin-
ancial support.
[1] For reviews, see: a) G. Raabe, J. Michl, Chem. Rev. 1985, 85,
419–509; b) A. G. Brook, M. Brook, Adv. Organomet. Chem.
1996, 39, 71–158; c) T. Müller, W. Ziche, N. Auner in The
Chemistry of Organosilicon Compounds, vol. 2, part 2 (Eds.: Z.
Rappoport, Y. Apeloig), Wiley, New York, 1998, chapter 16;
d) T. L. Morkin, W. J. Leigh, Acc. Chem. Res. 2001, 34, 129–
136; e) T. L. Morkin, T. R. Owens, W. J. Leigh, in The Chemis-
try of Organosilicon Compounds, vol. 3 (Eds.: Z. Rappoport, Y.
Apeloig), Wiley, New York, 2001, chapter 17, p. 949–1026; f)
L. E. Gusel’nikov, Coord. Chem. Rev. 2003, 244, 149–240; g)
V. Ya. Lee, A. Sekiguchi, Organometallics 2004, 23, 2822–2834;
h) H. Ottosson, P. G. Steel, Chem. Eur. J. 2006, 12, 1576–1585.
[2] For reviews, see: a) K. M. Baines, W. G. Stibbs, Adv. Or-
ganomet. Chem. 1996, 39, 275–324; b) J. Escudié, H. Ranaivon-
jatovo, Adv. Organomet. Chem. 1999, 44, 113–174; c) J. Escudié,
For reviews on 31P chemical shifts, see: S. Lochschmidt, A.
Schmidpeter, Phosphorus Sulfur 1986, 29, 73–109.
[12]
[13]
a) K. M. Baines, W. G. Stibbs, Coord. Chem. Rev. 1995, 145,
157–200; b) C. E. Holloway, M. Melnik, Main Group Met.
Chem. 2002, 25, 185–266.
M. Lazraq, C. Couret, J. Escudié, J. Satgé, M. Draeger, Orga-
nometallics 1991, 10, 1771–1778.
In the case of the silene (Me3Si)2Si=C(OSiMe3)R (R = tBu,
Ad) produced by photolysis, a [2 + 4] cycloaddition occurred
between the Si=C double bond and the two C=O double bonds
of benzil, see: A. Naka, M. Ishikawa, J. Organomet. Chem.
2003, 685, 162–167.
A [2 + 4] cycloaddition leading to a six-membered ring deriva-
tive has also been reported between the Ge=P double bond of
[14]
[15]
[16]
Eur. J. Inorg. Chem. 2011, 281–288
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D. Ghereg, H. Gornitzka, J. Escudié
FULL PAPER
the phosphagermene Mes*P=GeMes2 and the two C=O
double bonds of benzil, see: A. Kandri Rodi, J.-P. Declercq, A.
Dubourg, H. Ranaivonjatovo, J. Escudié, Organometallics
1995, 14, 1954–1960.
atom by a [1 + 4] cycloaddition, and the Ge=C double bond
is not involved, see: W.-P. Leung, K.-W. Kan, C.-W. So, T. C. W.
Mak, Organometallics 2007, 26, 3802–3806.
[18] G. M. Sheldrick, Acta Crystallogr., Sect. A 1990, 46, 467–473.
[19] G. M. Sheldrick, Acta Crystallogr., Sect. A 2008, 64, 112–122.
Received: July 8, 2010
[17] The transient germavinylidene [Me3SiN=P(Ph2)]2C=Ge: pos-
sesses both a Ge=C double bond and a germylene function.
Reaction with benzil occurs exclusively on the germanium
Published Online: December 7, 2010
288
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