Some Aspects of Chemistry of the N->Si Chelated Aryloxydihydrosilanes R(ArO)SiH2(R = Ph, ArO) and of the 2,2-Diaryloxytrisilane (Me3Si)2Si(OAr)2{ArO = 2,4,6-[(CH3)2NCH2]3C6H2O}

Article abstract of DOI:10.1016/S0022-328X(02)01633-9

Reactions of the pentacoordinate aryldioxydihydrosilane Ph(Ar)SiH2 (1) with hydroxyl groups, carbonyl derivatives and PCl5 resulted in formation of new alcoxylated, phenoxylated and halogenated hydrosilanes Ph(ArO)(H)X (X = Cl, OR, OAr, OC(O)R), respectively. Treatment of the hexacoordinated (4+2) diaryloxydihydrosilane (ArO)2SiH2 (2) with N-chloro- or N-bromosuccinimide, trimethylsilyltriflate or iodine yielded the novel stable silicenium ion [(ArO)2(H)Si](1+)X(1-). Reactions of 2 with sulfur S8 and the transition metal complex Fe(CO)5 have resulted in the isolation of the new complexes (ArO)2Si = E [E = S, Fe(CO)4]. Decomposition modes of the tetracoordinate 2,2-diaryloxytrisilane (Me3Si)2Si(OAr)2 (3) on thermolysis and photolysis have also been studied; two pathways involving formation of the two silylenes (ArO)(Me3Si): and (ArO)2Si: have been identified by trapping experiments

Full text of DOI:10.1016/S0022-328X(02)01633-9

Journal of Organometallic Chemistry 658 (2002) 94ꢃ105
/
www.elsevier.com/locate/jorganchem
Some aspects of chemistry of the N0
aryloxydihydrosilanes R(ArO)SiH (RꢀPh, ArO) and of the 2,2-
diaryloxytrisilane (Me Si) Si(OAr) {ArOꢀ2,4,6-
/
Si chelated
/
2
/
3
2
2
[
(CH ) NCH ] C H O}
3 2 2 3 6 2
Aman Akkari-El Ahdab, Ghassoub Rima, Heinz Gornitzka, Jacques Barrau *
H e´ t e´ rochimie Fondamentale et Appliqu e´ e, UMR-5069 du CNRS, Universit e´ Paul-Sabatier, 118, route de narbonne, 31062 Toulouse, Cedex 4, France
Received 27 February 2002; accepted 31 May 2002
Abstract
Reactions of the pentacoordinate aryloxydihydrosilane Ph(ArO)SiH
resulted in formation of new alcoxylated, phenoxylated and halogenated hydrosilanes Ph(ArO)(H)X (Xꢀ
respectively. Treatment of the hexacoordinated (4ꢁ2) diaryloxydihydrosilane (ArO) SiH (2) with N-chloro- or N-bromosucci-
2
(1) with hydroxyl groups, carbonyl derivatives and PCl
5
/
Cl, OR, OAr, OC(O)R)
/
2
2
ꢁ
ꢂ
nimide, trimethylsilyltriflate or iodine yielded the novel stable silicenium ion [(ArO) (H)Si] X . Reactions of 2 with sulfur S and
2
8
the transition metal complex Fe(CO)
Decomposition modes of the tetracoordinate 2,2-diaryloxytrisilane (Me
5
have resulted in the isolation of the new complexes (ArO)
2
Siꢀ
/
E [Eꢀ
/
4
S, Fe(CO) ].
3 2 2
Si) Si(OAr) (3) on thermolysis and photolysis have also
been studied; two pathways involving formation of the two silylenes (ArO)(Me Si): and (ArO) Si: have been identified by trapping
3
2
experiments. # 2002 Elsevier Science B.V. All rights reserved.
Keywords: Silicon; Hypercoordination; Silicenium; Silanethione; Silanediylꢃ
/transition metal complexes; Silylene
1
. Introduction
a
4ꢂnSi(OAr)n and RSiH (OAr)
(ArOꢀ
3
/
2,4,6-
Ph,
1, 2); some of these compounds present an
n
3ꢂn
[
(CH ) NCH ] C H O; aꢀ
/
Cl, Me, Me Si; Rꢀ
/
3
2
2 3
6
2
Current interest in the chemistry of hypercoordinated
ArO; nꢀ
/
silicon compounds lies in use of their extreme reactivity.
Various publications report that pentacoordinated hy-
drosilanes present a particularly reactive hydrogen
function and behave as better hydride donors and
reducting agents than simple silicon hydrides; particular
catalytic properties were also highlighted for such
derivatives [1,2]. Moreover various studies showed that
hypervalent silicon center [14]. Herein we report on
peculiar chemical properties of the aryloxydihydrosi-
lanes Ph(ArO)SiH
silicon center is penta- and hexacoordinated (bicapped
Si
(1) and (ArO) SiH (2) in which the
2
2 2
tetrahedral) respectively [14]. In search for N0
/
intramolecularly stabilized silylenes we also report on
the thermolysis and photolysis of the tetracoordinate
2,2-diaryloxytrisilane (Me Si) Si(OAr) (3).
3 2 2
trisilanes could be convenient sources of silylenes [R Si:]
2
the fugacity and the great reactivity of which were also
underlined [3ꢃ13].
/
We have recently reported a series of new silicon
compounds with as supporting ligand a phenoxy group
bearing in 2,4,6 positions (dimethylamino)methyl
groups suitable for intramolecular coordination
2. Results and discussion
2
.1. Hydrolysis of 1ꢃ
/
3
The aryloxysilanes 1, 2 are extremely sensitive to
hydrolysis. A nucleophilic assistance due to an intramo-
*
Corresponding author. Tel.: ꢁ
204
E-mail address: barrau@chimie.ups-tlse.fr (J. Barrau).
/
33-5-6155-6172; fax: ꢁ33-5-6155-
/
lecular Siꢀ ꢀ ꢀN coordination explains the important
8
0
activation of the Siꢁ/O bonds of these hypercoordinate
022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 6 3 3 - 9

A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ
/
105
95
silicon complexes. The silane 3 is also particularly
sensitive to hydrolysis; since this compound adopts a
silicon tetracoordinated structure, an activation of the
Table 1
˚
3 2 3
Selected bond lengths (A) and angles (8) for [(Me Si) SiO]
Bond lengths
Siꢁ
/
O bonds by a chelate system can not be invoked in
Si(1)ꢁSi(2)
Si(2)ꢁSi(3)
Si(2)ꢁO(1)
Si(2)ꢁO(3)
Si(4)ꢁSi(5)
Si(5)ꢁSi(6)
Si(5)ꢁO(1)
Si(5)ꢁO(2)
Si(7)ꢁSi(8)
Si(8)ꢁSi(9)
Si(8)ꢁO(2)
Si(8)ꢁO(3)
2.361(2)
2.361(2)
1.650(2)
1.659(2)
2.353(2)
2.365(2)
1.654(2)
1.657(2)
2.366(2)
2.361(2)
1.649(2)
1.648(3)
this case. However, such a ‘nucleophile assisted’ hydro-
lysis involving a pentacoordinated intermediate may be
effective after the first hydrolysis of one Siꢁ
thus explain the very fast formation of the siloxane
(Me Si) SiO] . This trisiloxane, already described [15],
/O bond, and
[
3
2
3
was crystallized in chloroform at 20 8C. The structure
was determined by X-ray diffraction studies. Fig. 1
shows the molecular structure and Table 1 summarizes
selected bond lengths and bond angles. This structure is
comparable to those of trisiloxanes previously reported
Bond angles
[
16]. The molecule has D symmetry. The heterocycle
3
O(1)ꢁSi(2)ꢁO(3)
O(3)ꢁSi(8)ꢁO(2)
O(1)ꢁSi(5)ꢁO(2)
Si(2)ꢁO(1)ꢁSi(5)
Si(8)ꢁO(2)ꢁSi(5)
Si(1)ꢁSi(2)ꢁSi(3)
Si(4)ꢁSi(5)ꢁSi(6)
Si(7)ꢁSi(8)ꢁSi(9)
Si(8)ꢁO(3)ꢁSi(2)
106.45(12)
106.19(11)
106.20(12)
133.49(13)
133.93(17)
110.47(6)
109.82(5)
111.78(5)
133.68(15)
Si O is perfectly plan (the sum of angles of cycle Si O
3 3
3
3
˚
is of 719.98). The Siꢁ
agreement with literature values, and the average values
of the OꢁSiꢁO and SiꢁOꢁSi angles are 133.7 and
06.288 respectively, (near by ꢀ18 close to those
observed in (t-Bu SiO) [16a]). All three SiꢁSiꢁSi angles
/
O bond length (1.63 A) is in good
/
/
/
/
1
/
/
/
2
3
are different (109.82, 110.47, 111.788) and slightly
smaller than those observed in various other trisiloxanes
[
17].
tative yields of many compounds, e.g. the alcoxyl and
aryloxyl derivatives 4 and 5 or the silyl ester 6 (Scheme
2
agent
.2. The dihydrosilane Ph(ArO)SiH (1) as reducing
2
1
).
Partial chlorination of 1 can be easily carried out in
homogeneous phase by PCl in CHCl ; the aryloxyha-
5
3
The dihydrosilane 1, which presents (according to its
logenohydride 7 is thus obtained in good yield (Scheme
).
Compound 1 can also give reactions with carbonyl
physicochemical characteristics) a pentacoordinated si-
licon (dynamic coordination) [14], possess a much more
reactive hydrogen function than the simple organosili-
1
derivatives; in absence of any catalyst, Ph(ArO)SiH2
condenses easily on benzaldehyde to give the alcoxyar-
yloxyhydride 8 (Scheme 1).
con hydride Ph(PhO)SiH ; it reacts very quickly with
2
hydroxyl groups allowing the syntheses in near quanti-
All these reactions are characteristic of silicon hy-
drides with a pentacoordinated silicon.
The new silanes 4ꢃ8, with multiple functions, are
/
relatively thermically stable and were fully physico-
chemically characterized. Note, as already observed
for silicon esters with pentacoordinated silicon [18],
that ester 6 decomposes thermically at relatively low
temperatures (150 8C) leading to the trisiloxane 9
probably via the intermediate silanone [Ph(ArO)Siꢀ
/O]
(
9?) (Scheme 2).
2
(
.3. Some aspects of the reactivity of the dihydrosilane
ArO) SiH (2)
2
2
The various reactions which were studied are sum-
marized by Scheme 3. They point out that the chemical
properties of the hexacoordinated (4ꢁ2) silicon dihy-
dride (ArO) SiH (2) [14] differ greatly from those
/
2
2
observed for various tetracoordinated and pentacoordi-
nated silicon dihydrides.
Fig. 1. Solid-state structure and atom numbering scheme of [(Me
Si) SiO]
3
-
2
3
.

96
A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ105
/
Scheme 1.
Though the reactivity of the dihydrosilane (Ar-
O) SiH towards compounds with an hydroxyl function
These properties evoke ionic structure of the type
ꢁ
ꢂ
[(ArO) SiH] X ] for the compounds 2aꢃ
/
d, compar-
able with those already observed for hydrosilyl cations
2
2
2
is completely comparable with that of Ph(ArO)SiH2,
allowing thus easy passage from (ArO) SiH to (Ar-
O) SiH (10) in near quantitave yield, its reactivity
ꢁ
ꢂ
[RR?Si(H)] X [19ꢃ
/
23]. Confirmation of the ionic
2
2
1
d was obtained by H-, Si-,
29
nature of derivatives 2aꢃ
/
3
1
5
13
N-, C-NMR spectroscopies, FAB mass spectrometry
towards carbonyl derivatives is on the contrary practi-
cally nil and reflects a quasi-inertia of 10 towards
nucleophiles (Scheme 3).
(positive and negative modes), IR and conductivity
measurements. The observed data are almost identical
(
philes such as N-chloro- or N-bromosuccinimide, tri-
ArO) SiH is very reactive towards various electro-
for all derivatives 2aꢃ
/
d, being hence characteristic of the
2
2
same species.
2
9
methylsilyl trifluoromethanesulfonate and iodine
(
The Si-NMR (proton coupled) spectra of all these
derivatives display a doublet dꢀ 106.3 upfield com-
pared with the characteristic signal of the SiH group of
Scheme 3). In all the cases the reaction seems to
/
ꢂ
/
proceed by extrusion of an hydride ion to induce the
formation of a silyl cation. All these reactions lead to
white powders, insoluble in hexane, benzene and diethy-
lether, soluble in dichloromethane and chloroform.
2
2
9
the starting dihydrosilane. The Siꢁ
/
H coupling con-
1
stant ( JSiꢁHꢀ
/
345 Hz) is definitely increased compared
with that of the parent silane reflecting thus a strong s
Scheme 2.

A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ
/
105
97
these signals (dꢀ
/
ꢂ336 ppm) express also that two o-
/
NMe groups are chelated on the silicon atom in this
2
compound.
All these spectroscopic characteristics for the com-
pounds 2aꢃd are consistent with an ionic silyl cation
/
structure; silicon being most probably pentacoordinated
with two ortho nitrogen atoms in apical positions
(
Scheme 4).
In such a geometry, almost a trigonal bipyramid in
which nitrogens occupy axial positions, the two aryloxy
groups are chemically equivalent. The two resonances
1
observed in the H-NMR spectrum for the two o-NMe
2
groups (one on each ArO group) coordinated to the
silicon atom are due to the diastereotopic character of
the N-methyl groups at each one of the two nitrogens.
ꢂ
It is worth noting that the counter-anion X has a
1
weak influence on the chemical shifts in the H-, Si-
29
Scheme 3.
1
and N-NMR spectra of these [(ArO) SiH] X com-
5
ꢁ
ꢂ
2
2
H bond as expected for a sp -
pounds. Coordination of nucleophilic anions to a silyl
cation having been already observed [20], we could also
character of the Siꢁ
/
hybridized silicon atom. An intramolecular Nꢀ ꢀ ꢀSi
2
coordination, allows stabilization of this sp -hybridized
consider such a coordination in compounds 2aꢃd; these
/
derivatives would then adopt a structure in which silicon
is not pentacoordinated, as proposed, but rather hex-
acoordinated. In this case only an octahedral structure
silicon, and may also explain the upfield chemical shift
compared with the parent dihydrosilane) observed in
(
the Si-NMR spectrum. The same type of evolution
2
9
ꢁ
ꢂ
was observed by Corriu and Belzner for [L SiH]
2
with the hydrogen atom and the anion X trans to each
other could be in agreement with the spectroscopic
systems with silicon stabilized by L ligands of the type
8-(dimethylamino)naphthalene [21c] and 2-[(dimethyla-
mino)methyl]phenyl [20] respectively, but the opposite
observations. Two geometries of C and C types are
2
s
possible (Scheme 5).
The IR spectra of 2aꢃ
silylium structure since they present in all cases a strong
shift was noted with the 2,6-bis[(dimethylami-
no)methyl]phenyl ligand [21a].
/d are also consistent with a
1
ꢂ1
H-NMR spectra of 2aꢃ
/
d at 20 8C all indicate
y
band at 2200 cm characteristic of a silylium ion
SiꢁH
[21], remaining however close to that of the starting
coordination of two o-NMe groups on the silicon
2
1
atom since in all cases the H-NMR spectra display
dihydrosilane (ArO) SiH .
2
2
four singlets for the 36 protons of the six NMe groups
2
The positive ion FAB mass spectra of these deriva-
tives show the parent ion at m/z corresponding to the
ꢁ
ꢂ
[
for example for [(ArO) SiH] TfO dꢀ
/
2.15 (12H),
.35 (12H), 2.62 (6H), 2.85 (6H)] and two singlets [dꢀ
.41 (4H), dꢀ3.55 (4H)] for the 12 protons of the six
4.09 (2H), d ꢀ
2
ꢁ
2
3
/
silylium [(ArO) SiH] in all cases.
2
/
Furthermore the ionic nature of these compounds has
also been confirmed by conductivity measurements. The
specific conductivity of the compounds [(ArO)2-
CH N groups and an AB system [d ꢀ
4
/
/
2
A
B
2
.50 (2H), JABꢀ
/
14.66 Hz].
The C-NMR (CDCl ) gives few informations on the
1
3
ꢁ
ꢂ
ꢁ
ꢂ
3
SiH] Br and [(ArO) SiH] TfO , for example, are
2
existence of this coordination since one observes, for 2a
for example, only two signals at dꢀ44.81 and 45.27
ppm for the 12 methyl carbons and three signals at dꢀ
9.12, 59.78 and 62.84 ppm for the six methylenic
carbons of the dimethylaminomethyl groups.
2
4.9 and 30.2 ns cm per equivalent, respectively (Fig.
2
/
2
).
/
5
1
5
The N-NMR spectrum of 2a (CCl , CDCl ) exhibits
3
4
three signals at dꢀ
348.5 ppm (2 Npara), ꢂ
only two signals at dꢀ
348.4 ppm (4 Northo) were observed for the dihydro-
silane (ArO) SiH for which, as previously shown [14], a
/
ꢂ
/
336 ppm (2 coordinating Northo),
351 ppm (2 Northo), whereas
347.4 ppm (2 Npara) and
ꢂ
/
/
/
ꢂ
/
ꢂ
/
2
2
dynamic Nꢀ ꢀ ꢀMꢀ ꢀ ꢀN coordination sequence in solution
renders the four o-NMe groups equivalent. In the
2
spectrum of 2a the splitting of the signal of the four
ortho nitrogen atoms and the down field shift of one of
Scheme 4.

98
A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ105
/
Scheme 6.
method the silylene-iron tetracarbonyl complex (Ar-
O) SiFe(CO) (11) was obtained in good yield by
2
4
appropriate workup after simple mixing of (ArO) SiH
2
2
and Fe(CO) at room temperature in pentane during 5
5
h. This complex obtained as brown solid is soluble in
aromatic solvents, insoluble in pentane and presents a
great sensitivity to oxygen and moisture. It has been
Scheme 5.
1
13
29
characterized by spectroscopic H-, C-, Si-NMR,
1
mass and IR analyses. In the H-NMR at room
These results underline the strong bidendate nature of
the 2,4,6-tris((dimethylamino)methyl)phenoxy ligand,
temperature the equivalence of the four o-NMe groups
2
ꢁ
ꢂ
which induces the ionic structure [(ArO) SiH] X of
2
denotes a dynamic flip-flop coordination, identical to
that observed for the parent silane (ArO) SiH . In the
compounds 2aꢃ
/
d. It is worth noting that these deriva-
2
2
1
3
tives are significantly different from the only three other
known to date (RO) SiH(X) compounds; these deriva-
C-NMR the carbonyl groups appear at dꢀ210.98
/
revealing, in solution at room temperature, a fast
exchange (on the NMR time scale) of equatorial and
axial carbonyls. The IR data in the n(CO) region (three
absorption bands) are characteristic of an axial coordi-
nation of the divalent silicon to iron (C3v symmetry); a
complex of C2v symmetry with Si(OAr)2 group in
equatorial position of the trigonal bipyramidal-coordi-
2
tives containing the Me Nꢁ
/
Nꢀ
are neutral complexes with hexacoordinated silicon
atoms [24ꢃ26] (Scheme 6).
/
C(R?)O bidentate ligand
2
/
It has been noted that dehydrogenative/coupling
reactions of pentacoordinated dihydrosilanes with metal
carbonyls give efficient synthetic routes for preparation
of silanediyl-transition metal complexes stabilized by
nated iron atom, should present four IR bands (2A ꢁ
/
1
intramolecular coordination [27ꢃ
/
30]. According to this
B ꢁ
/
B ) (Scheme 7). It seems that the divalent silicon
2
1
Fig. 2. The conductivity (x) as a function of the amount of electrophilic reagent added (x) to a solution of 0.53 mmol lꢂ1 of silane 1 in CHCl
.
3

A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ
/
105
99
the first isolable silanethione (Tbt)(Tip)Siꢀ
/
S {Tbtꢀ
/
2
,4,6-tris[bis(trimethylsilyl)methyl)phenyl]-, Tipꢀ
/
2,4,6-
triisopropylphenyl-} which is stabilized sterically has
been reported [38].
2
(
.4. Thermolysis and photolysis of the trisilane
Me Si) Si(OAr) (3)
Scheme 7.
3
2
2
It is commonly accepted that polysilanes are effective
sources of intermediate silylenes [3ꢃ14]. The UV char-
acteristics (the maximum absorption band shifted to-
Si(OAr) ligand acts as a strong s-donor and a weak p-
2
/
acceptor towards iron since theoretical studies have
shown (i) that the axial or equatorial preference for a
8
ligand L in the trigonal bipyramid carbonyl-d metal (0)
wards the longwave lengths region) and the observed
structure (relatively small Siꢁ
/
Siꢁ
/
Si angle) of compound
[14] have incited us to consider the thermolysis and
complexes is dependent on the s-donor and p-acceptor
characters of the ligand (ii) that low s-donor and good
3
photolysis of this trisilane as potential source of the
p-acceptor ligands prefer equatorial sites [31ꢃ
/
33].
silylene (ArO) Si, expecting a sufficient Nꢀ ꢀ ꢀSi intramo-
2
The mass spectrum presents the molecular ion peak
weak intensity) and the fragmentation pattern char-
lecular coordination to allow its stabilization at room
temperature as a monomer (or dimer). Few studies
concerning the synthesis of Nꢀ ꢀ ꢀSi stabilized silylene
(
acteristic of this structure (prominent peaks resulting
from loss of the carbonyl groups and of the ArO groups
on the silicon).
species have been performed [10ꢃ13]; to date no
/
compound of this type has been isolated at room
temperature.
Early reports of Corriu and col. have shown that
compounds with double bonded silicon (R Siꢀ
/
Y) are
2
On heating to 120 8C under anaerobic conditions for
several hours or under UV irradiation (with a low
pressure mercury lamp at 20 8C), (Me Si) Si(OAr)
sufficiently stabilized by intramolecular complexation
with a lewis base to permit their isolation as monomers
3
2
2
[10,27,34]. Similarly the reaction of molecular sulfur
with (ArO) SiH in chloroform at room temperature
decomposes in presence of excess of silylene trapping
agents (ethanol or 2,3-dimethylbuta-1,3-diene) affording
2
2
gives the stable monomer (ArO) Siꢀ
/
S (12) which can be
formally considered as an adduct of the silylene
ArO) Si and sulfur; 12 is thermically stable and has
2
the silicon compounds 13ꢃ18. These trapping experi-
/
ments indicate that the decompositions are not specific
forming both the heteroleptic silylene (ArO)(Me Si)Si:
(
2
3
been characterized physicochemically. Mass spectro-
scopy analysis by electronic impact (70 eV) shows that
the molecular ion peak is not detectable, the main peaks
(
3a) [way 1] and the homoleptic silylene (ArO) Si (3b)
2
[
way 2], as shown in Scheme 9. Yields of these reactions
are low (B40%); the path 1 is always dominating on
path 2 and more particularly in thermolysis [thermolysis
Dꢀ120 8C): 3a/3bꢀ95/5; photolysis (hnꢀ254 nm):
3a/3bꢀ75/25].
/
ꢁ
are attribuable to the fragment [Mꢁ
/
S] corresponding
to the divalent silicon species. The particular stability at
room temperature of 12 is probably due to on Nꢀ ꢀ ꢀSi
intramolecular coordination giving a structure between
the two mesomeric forms represented in Scheme 8. Such
structures have been previously evoked for Si, Ge, and
(
/
/
/
/
Photolysis of 3 is not so selective as its thermolysis
since the formation of the four silanes (Me3-
Si) Si(OAr)H, Me SiSi(OAr) H and [(Me Si) Si(OAr) -
2
3
2
3
2
2
Sn species [21a,21b,35ꢃ/37] (Scheme 8). Quite recently
1 or 2 H Cꢀ
/
NMe] are observed (mass spectrometry) in
2
Scheme 8.

100
A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ
/
105
Scheme 9.
small proportions in addition to those of Me SiOAr and
3
behavior of 3 under electronic impact since its mass
spectrum (EI (electron impact) at 70 eV) shows the three
Me SiSiMe . Note that (Me Si) Si(OPh) , the phenoxy-
3
3
3
2
2
ꢁ
ꢁ
lated analogue of 3, is thermically stable under the
thermolysis conditions of 3 (it is necessary to maintain
ion peaks [Mꢁ
/
OAr] (100), [Mꢁ/Me Si] (42) and
3
ꢁ
[M] (17%).
this derivative at 250 8C during 48 h to observe ꢀ
/
25%
of decomposition).
Intramolecular stabilizations of the two divalent
species 3a and 3b are not sufficient enough to allow
their physicochemical characterization at room tem-
perature; 3a and 3b have been only chemically char-
acterized in situ by condensation on 2,3-dimethylbuta-
3. Experimental
3.1. General procedures
All the compounds described are sensitive to oxygen
1
,3-diene or ethanol (Scheme 9). However, interestingly
and moisture. All manipulations were performed under
an inert atmosphere of nitrogen or argon using standard
Schlenk and high-vacuum-line techniques. Dry, oxygen-
free solvents were employed throughout. All solvents
were distilled from sodium benzophenone before use.
ꢂ1
the addition of oxygen to a 10
immediately after irradiation, led to the formation of the
disiloxane [(Me Si)(ArO)SiO] (characterized by mass
M solution of 3
3
2
spectroscopy). This siloxane can be regarded as the
product of (i) the direct oxidation of the intermediate
silylene 3a followed by dimerisation of the silanone thus
formed (ii) the direct oxidation of the intermediate
1
H-NMR spectra were recorded on a Bruker AC 80
spectrometer operating at 80 MHz (chemical shifts are
reported in parts per million relative to internal Me Si as
4
1
reference) and C spectra on a AC 200 spectrometer
3
disilene [(Me Si)(ArO)Siꢀ
/Si(OAr)(SiMe )] (3c) resulting
3
3
1
3
from dimerization of 3a. It is quite reasonable to assume
the presence of 3c since was observed an entity of
molecular mass corresponding to disilene 3c in the mass
spectrum of a sample of 3 which was irradiated for 2 h at
room temperature.
operating at 50.32 MHz; the multiplicity of the C-
NMR signals was determined by the APT technique.
2
9
Si-NMR spectra were recorded on a Bruker ARX 400
operating at 79.47 MHz (Chemical shifts are reported in
parts per million relative to external Me Si as reference).
4
1
5
Although a more detailed study of these thermolysis
and photolysis reactions is necessary, these first results
N spectra were recorded on a Bruker ARX 400
spectrometer (chemical shifts are reported in parts per
(
low yields of decomposition and path 1 dominating)
million relative to external nitromethane as reference).
1
F-NMR spectra were recorded on a Bruker spectro-
meter AC 200 operating at 188.3 MHz (chemical shifts
are reported in parts per million relative to external
trifluoroacetic acid as reference). Mass spectra under EI
9
highlight the particular stability of the intermediate silyl
radicals [(Me Si)(ArO) Si] and [(Me Si) Si(OAr)] prob-
ably involved in the first step of these decomposition
reactions. These observations are in agreement with the
3
2
3
2

A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ
/
105
101
or chemical ionisation (CH ) conditions at 70 and 30 eV
4
3.4. Reaction of phenylsilane with 2,4,6-
tris((dimethylamino)methyl)phenol
were obtained on Hewlett-Packard 5989 and Nermag
R10-10H spectrometers. FAB spectra were performed at
the service commun de spectrometrie de masse de
A mixture of PhSiH (0.07 g, 0.65 mmol) and 2,4,6-
3
l’Universite Paulꢃ
were carried out at 25 8C by using a low-pressure
mercury immersion lamp in a quartz tube (lꢀ254 nm).
IR and UV spectra were recorded on PerkinꢃElmer
600 FT-IR and Lambda-17 spectrophotometers. Melt-
/
Sabatier de Toulouse. Irradiation
tris((dimethylamino)methyl)phenol (0.52 g, 1.96 mmol)
leads to 5 (0.18 g, 31%).
/
3.5. Reaction of 1 with acetic acid
/
1
A solution of acetic acid (0.02 g, 0.32 mmol) in
ing points were taken uncorrected on a Leitz Biomed
hot-plate microscope apparatus. Elemental analyses (C,
H, N) were performed at the Microanalysis Laboratory
of the Ecole Nationale Sup e´ rieure de Chimie de
Toulouse.
chloroform (10 ml) was added to 1 (0.12 g, 0.32 mmol)
in chloroform (10 ml). The reaction mixture was stirred
at r.t. for 12 h. The volatiles were removed in vacuo to
2
9
afford 6 (0.13 g, 95%). Compound 6:
Si-NMR
1
(
2
CDCl ): ꢂ
/
63 (d, JSiꢁHꢀ
.07 (s, 3H), 2.16 (s, 6H), 2.22 (s, 12H), 3.23 (s, 2H),
.37(s, 4H), 5.22 (s, 1H), 7.07 (s, 2H), 7.3ꢃ7.5 (m, 5H).
/
304 Hz). H-NMR (CDCl ):
3
3
3
1
/
3
3.2. Reaction of 1 with 2,4,6-
tris((dimethylamino)methyl)phenol
C-NMR (CDCl ): 21.20, 45.10, 45.19, 60.22, 63.88,
3
1
1
27.03, 127.65, 128.62, 130.27, 131.74, 132.42, 136.52,
ꢂ1
52.01, 161.82. IR (KBr, CDCl , cm ): nSiꢁHꢀ2201;
/
3
ꢁ
A solution of 2,4,6-tris((dimethylamino)methyl)phe-
nol (0.14 g, 0.53 mmol) in 10 ml of pentane was added
slowly to a stirred solution of [2,4,6-tris((dimethylami-
no)methyl)]-phenylsilane (0.2 g, 0.53 mmol) in 15 ml of
pentane. The reaction mixture was stirred at room
nCO
ꢀ
/
1693. MS: m/zꢀ
/
428 [Mꢂ1] . Anal. Calc. for
/
C H N O Si (Mꢀ
/429.63): C, 64.30; H, 8.21; N, 9.78.
2
3
35
3
3
Found: C, 64.09; H, 8.43; N, 9.63%.
3.6. Reaction of 1 with phosphorus pentachloride
temperature (r.t.) until evolution of H was ceased (3
2
h). The volatiles were removed in vacuo and the residue
was distilled under vacuum to give 4 (0.32 g, 94%).
To a solution of phosphorus pentachloride (0.08 g, 0.4
mmol) in 10 ml of chloroform was added dropwise a
solution of 1 (0.15 g, 0.4 mmol) in 10 ml of chloroform.
The mixture was stirred at r.t. for 2 days, the solvent was
removed under vacuum and ether (15 ml) was added. By
filtration 7 was obtained as a white solid (0.08 g, 50%).
ꢂ2
29
mmHg. Si-
15
Compound 4: b.p. 180ꢃ
/
182 8C/5ꢄ
/
10
1
NMR (CDCl ): ꢂ46.7 (d, JSiꢁHꢀ288 Hz). N-NMR
/
/
3
1
350.2. H-NMR (CDCl ): 1.95 (s,
(
CDCl ): ꢂ
/
347.7, ꢂ
/
3
3
1
1
2H), 2.20 (s, 24H), 3.30 (s, 4H), 3.38 (s, 8H), 5.25 (s,
1
3
29
1
H), 7.05 (s, 4H), 7.10ꢃ
/7.40 (m, 5H).
C-NMR
Compound 7: Si-NMR (CDCl
3
): ꢂ
/
71.8 (d, JSiꢁH
ꢀ
/
1
28.4 Hz). H-NMR (CDCl ): 2.02 (s, 6H), 2.25 (s,
3
1
2
4
1
(
CDCl ): 45.00, 45.31, 59.21, 63.88, 127.38, 127.57,
28.54, 130.04, 131.20, 132.16, 136.60, 151.42. IR
3
3
2H), 3.52 (s, 2H), 3.80 (s, 4H), 5.71 (s, 1H), 7.05 (s,
1
H), 7.15ꢃ7.39 (m, 5H). C-NMR (CDCl ): 45.12,
5.25, 59.20, 64.01, 126.91, 127.46, 128.64, 130.10,
31.41, 132.18, 136.48, 151.49. IR (KBr, CDCl ,
1
3
ꢂ1
/
(
CDCl , KBr, cm ): nSiꢁHꢀ
/
2205. MS: m/zꢀ
/634
3
3
ꢁ
[
M] . Anal. Calc. for C H N O Si (Mꢀ634.97): C,
/
3
6
58
6
2
6
1
8.09; H, 9.21; N, 13.24. Found: C, 67.79; H, 9.41; N,
3.50%.
3
ꢂ1
ꢁ
cm ): nSiꢁHꢀ
/
2195. MS: m/zꢀ
/
404 [Mꢂ1] . Anal.
/
Calc. for C H N OClSi (Mꢀ406.04): C, 62.12; H,
/
2
1
32
3
7.94; N, 10.35. Found: C, 62.31, H, 8.12; N, 10.14%.
3.3. Reaction of 4 with 2,4,6-
tris((dimethylamino)methyl)phenol
3.7. Reaction of 1 with benzaldehyde
A solution of benzaldehyde (0.034 g, 0.32 mmol) in
Using the same experimental procedure as for the
synthesis of 4, the reaction of 4 (1.2 g, 1.89 mmol) with
chloroform (10 ml) was added dropwise to 1 (0.12 g,
.32 mmol) in chloroform (10 ml). The mixture was
stirred at r.t. for 24 h. After removal of the solvent, 8
0
2
mmol) afforded 5. Yield: 1.6 g, 94%. Compound 5:
,4,6-tris((dimethylamino)methyl)phenol (0.5 g, 1.89
2
9
was obtained (0.15 g, 99%). Compound 8: Si-NMR
2
9
1
1
Si-NMR (CDCl ): ꢂ9.7. H-NMR (CDCl ): 1.98 (s,
/
3
3
(CDCl ): ꢂ
/
66.7 (d, JSiꢁHꢀ
2.16 (s, 6H), 2.23 (s, 12H), 3.24 (s, 2H), 3.36 (s, 4H), 4.51
(s, 2H), 5.22(s, 1H), 7.07 (s, 2H), 7.30ꢃ7.52 (m, 10H).
C-NMR (CDCl ): 45.21; 45.12, 60.22, 63.86, 76.51,
/
304 Hz). H-NMR (CDCl ):
3
3
1
6
4
1
8H), 2.14 (s, 36H), 3.24 (s, 6H), 3.46 (s, 12H), 7.12 (s,
1
3
7.55 (m, 5H). C-NMR (CDCl ): 45.26,
H), 7.35ꢃ
/
/
3
1
3
5.52, 58.28, 59.17, 128.41, 128.93, 129.17, 129.63,
3
ꢁ
32.16, 132.87, 135.36, 149.76. MS: m/zꢀ
898.35): C, 68.18;
H, 9.31; N, 14.03. Found: C, 67.78; H, 9.01; N, 13.72%.
/897 [M] .
127.01, 127.64, 128.03, 128.12, 128.62, 129.10, 130.27,
131.72, 132.39, 136.48, 139.50, 151.52. IR (KBr, CDCl ,
Anal. Calc. for C H N O Si (Mꢀ
/
5
1
83
9
3
3
ꢂ1
ꢁ
cm ): nSiꢁHꢀ
/
2204. MS: m/zꢀ
/
476 [Mꢂ1] . Anal.
/

102
A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ105
/
Calc. for C H N O Si (Mꢀ
N, 8.80. Found: C, 70.18; H, 8.42; N, 8.56%.
/
477.71): C, 70.40; H, 8.23;
stirred at r.t. for 3 h. The solvent was removed under
vacuum and the residue yellow solid product 12 was
2
8
39
3
2
purified by crystallization from tolueneꢃ
ml) at ꢂ30 8C. Yield: 0.21 g, 96%. Compound 12: m.p.
45ꢃ146 8C. Si-NMR (CDCl ): ꢂ
(CDCl ): 2.23 (s, 12H), 2.45 (s, 24H), 3.26 (s, 4H),
/
pentane (1/1, 40
3
.8. Thermolysis of 6
/
2
9
1
1
/
/
82.3. H-NMR
3
Compound 6 (0.2 g, 0.5 mmol) was sealed in an
3
1
3
evacuated tube and heated at 150 8C for 12 h. After
cooling to r.t., the tube was opened and the product was
analyzed by NMR and mass spectroscopy. Decomposi-
tion of 6 was complete, and compound 9 was identified
3.48 (s, 8H), 6.93 (s, 4H). C-NMR (CDCl ): 45.39,
3
45.47, 63,37, 64.08, 123.20, 130.86, 131.04, 151.20. MS
ꢁ
(I.E.): m/zꢀ
/
556 [Mꢂ
/
S] . MS (IC/CH ): m/zꢀ
/
589
588.92):
4
ꢁ
[Mꢁ1] . Anal. Calc. for C H N O SSi (Mꢀ
/
/
3
0
52
6
2
2
9
as [Ph(ArO)SiO] . Compound 9: Si-NMR (CDCl ): ꢂ
/
C, 61.18, H, 8.90; H, 14.27. Found: 61.24; H, 8.69; N,
14.49%.
3
3
1
1.3. H-NMR (CDCl ): 2.12 (s, 18H), 2.26 (s, 36H),
8
3
1
3
3.28 (s, 6H), 3.30 (s, 12H), 7.01ꢃ7.82 (m, 21H). C-
NMR (CDCl ): 45.31, 45.52, 58.21, 59.12, 127.15,
/
3.12. Reaction of 2 with trimethylsilyl
trifluoromethanesulfonate
3
1
27.53, 128.23, 130.37, 131.65, 132.72, 136.56, 151.42.
ꢁ
MS: m/zꢀ
/
1155 [M] .
A solution of trimethylsilyl trifluoromethanesulfonate
(0.11 g, 0.5 mmol) in 10 ml of ether was added dropwise
3.9. Reaction of 2 with 2,4,6-
tris((dimethylamino)methyl)phenol
at ꢂ65 8C to a solution of 2 (0.28 g, 0.5 mmol) in 10 ml
/
of ether. The reaction mixture was warmed to r.t. and
stirred for 1 h. After filtration, the residue solid obtained
was washed twice with pentane (10 ml) and dried in
vacuo. Compound 2a (0.27 g, 77%) was isolated as a
A solution of 2,4,6-tris((dimethylamino)methyl)phe-
nol (0.20 g, 0.75 mmol) in chloroform (5 ml) was added
slowly to 2 (0.42 g, 0.75 mmol) in chloroform (10 ml).
An evolution of H was observed. The reaction mixture
2
white powder. Compound 2a: m.p. 125ꢃ
/
127 8C (dec.).
106 (d, JSiꢁHꢀ344 Hz).
CDCl ): ꢂ336.0, ꢂ348.5, ꢂ351.0.
2.69. H-NMR (CCl4ꢃ
CDCl ): 2.15 (s, 12H), 2.35 (s, 12H), 2.62 (s, 6H), 2.85
2
1
9
5
was stirred at r.t. for 24 h. Compound 10 was obtained
after evaporation of the solvent in vacuo. Yield: 0.55 g,
Si-NMR (CCl4ꢃ
/
CDCl ): ꢂ
/
/
3
N-NMR (CCl4ꢃ
/
/
/
/
3
2
9
1
19
1
9
0%. 10: Si-NMR (CDCl ): ꢂ
/
102 (d,
J
Hz). H-NMR (CDCl ): 2.02 (s, 18H), 2.15 (s, 36H),
SiꢁHꢀ
/
358
F-NMR (CCl4ꢃ
/
CDCl ): ꢂ
/
/
3
3
1
3
3
1
.26 (s, 6H), 3.28 (s, 12H), 5.11 (s, 1H), 7.03 (s, 6H). C-
3
3
NMR (CDCl ): 45.32, 45.50, 58.10, 59.02, 128.21,
(s, 6H), 3.41 (s, 4H), 3.55 (s, 4H), 4.09 (d, 2H, Jꢀ
Hz), 4.50 (d, 2H, Jꢀ14.66 Hz), 4.42 (s, 1H), 7.25 (s,
4H). C-NMR (CCl4ꢃCDCl ): 44.81, 45.27, 59.12,
59.78, 62.84, 119.98, 120.61 (q, JCFꢀ
131.57, 149.64. IR (KBr, CCl4ꢃCDCl , cm ): n
2189. MS (MNBA) FABꢁ0: m/zꢀ
FABB0: m/zꢀ149 [CF SO ] . Anal. Calc. for
C H N O F SSi (Mꢀ
/14.66
/
3
ꢂ1
13
1
30.35, 132.70, 151.29. IR (CDCl , KBr, cm ):
3
/
3
ꢁ
1
n
SiꢁHꢀ
/
2243. MS: m/zꢀ
C H N O Si (Mꢀ
/
821 [M] . Anal. Calc. for
822.25): C, 65.73; H, 9.68; N,
/315 Hz), 129.49,
ꢂ1
/
/
:
SiꢁH
4
5
79
9
3
3
ꢁ
1
5.33. Found: C, 65.89; H,9.85; N, 15.36%.
/
/
557 [(ArO) SiH] ,
2
ꢂ
/
/
3
3
3
.10. Reaction of 2 with pentacarbonyliron
/706.94): C, 52.67; H, 7.56; N,
3
1
53
6
5 3
11.89. Found: 52.63; H, 7.25; N, 11.56%.
A solution of pentacarbonyliron (0.11 g, 0.53 mmol)
in 10 ml of pentane was added slowly to a solution of 2
0.30 g, 0.53 mmol) in 15 ml of pentane. The mixture
was stirred at r.t. for 5 h. The precipitate formed was
3.13. Reaction of 2 with N-chlorosuccinimide
(
A suspension of N-chlorosuccinimide (0.08 g, 0.6
mmol) in dichloromethane (15 ml) was slowly added to
a solution of 2 (0.35 g, 0.6 mmol) in dichloromethane
(15 ml). The mixture was then stirred at r.t. for 12 h.
After the succinimide was filtered off and the solvent
was removed in vacuo, 2b was obtained as a white
filtered and dried in vacuo to afford pure 11 (0.15 g,
4
2
0%) as a maroon powder. Compound 11: Si-NMR
9
1
(
2
C D ): ꢂ98.9. H-NMR (C D ): 2.05 (s, 12H), 2.16 (s,
/
6
6
6 6
1
4H), 3.36 (s, 4H), 3.53 (s, 8H), 7.26 (s, 4H). C-NMR
3
(
1
C D ): 45.57, 45.71, 59.87, 64.81, 129.26, 130.26,
6 6
ꢂ1
32.64, 152.38, 210.98 (CO). IR (KBr, C D , cm ):
6
powder. Yield: 0.25 g, 70%. Compound 2b: m.p. 189ꢃ
/
6
ꢁ
29
nCO: 1958, 2010. MS (IC/NH ): m/zꢀ
/
725 [Mꢁ
724.75): C, 56.35;
H, 7.23; N, 11.60. Found: C, 56.31; H, 7.28; N, 11.82%.
/
1] .
190 8C (dec.). Si-NMR (CDCl ): ꢂ
/
105.9 (d, JSiꢁHꢀ
N-NMR (CDCl ): ꢂ336.2, ꢂ345.4,
350.4. H-NMR (CDCl ): 2.17 (s, 12H), 2.39 (s,
/
3
3
1
5
Anal. Calc. for C H N O FeSi (Mꢀ
/
344.2 Hz).
/
/
3
4
52
6
6
3
1
ꢂ
/
3
1
2H), 2.66 (s, 6H), 2.87 (s, 6H), 3.45 (s, 4H), 3.68 (s,
4H), 4.15 (d, 2H, Jꢀ17.1 Hz), 4.51 (d, 2H, Jꢀ17.1 Hz),
.43 (s, 1H), 7.34 (s, 4H). C-NMR (CDCl ): 43.62,
3
.11. Reaction of 2 with sulfur
/
/
1
3
4
3
To a stirred suspension of sulfur (0.012 g, 0.38 mmol)
in 10 ml of chloroform was added a solution of 2 (0.212
g, 0.38 mmol) in 10 ml of chloroform. The mixture was
44.40, 45.30, 58.76, 59.31, 61.94, 119.96, 131.04, 133.02,
ꢂ1
149.82. IR (KBr, CDCl , cm ): n
3
: 2207. MS
SiꢁH
ꢁ
(MNBA) FABꢁ
/
0: m/zꢀ
/
557 [(ArO) SiH] , FABB0:
/
2

A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ
/
105
103
ꢂ
m/zꢀ
5
8
/
35 [Cl] . Anal. Calc. for C H N O ClSi (Mꢀ
/
Si)Si(H)OEt was obtained. Yield: 0.09 g, 31%. (Ar-
1
3
0
53
6
2
93.32): C, 60.73; H, 9.00; N, 14.16. Found: C, 60.50; H,
.84; N, 13.86%.
O) Si(H)OEt: m.p. 189ꢃ
/
190 8C (dec.). H-NMR
2
3
(C D ): 1.12 (t, 3H, JHꢁHꢀ7 Hz), 2.05 (s, 24H), 2.14
/
6
6
3
(
s, 12H), 3.3 (s, 4H), 3.47 (s, 8H), 3.65 (q, 2H, JHꢁHꢀ7
Hz), 4.79 (s, 1H), 7.45 (s, 4H). MS: m/zꢀ602 [M] .
1
ArO(Me Si)Si(H)OEt: H-NMR (C D ): 0.25 (s, 9H),
/
ꢁ
3
.14. Reaction of 2 with N-bromosuccinimide
/
3
6
6
3
Using the same experimental procedure as for the
synthesis of 2a, the reaction of 2 (0.35 g, 0.6 mmol) with
N-bromosuccinimide (0.11 g, 0.6 mmol) afforded 2c.
1.15 (t, 3H, JHꢁHꢀ
/7 Hz), 2.04 (s, 12H), 2.12 (s, 6H),
3
3.25 (s, 2H), 3.43 (s, 4H), 3.67 (q, 2H, J
ꢀ7Hz),
/
HꢁH
411 [M] .
ꢁ
4.65 (s, 1H), 7.43 (s, 2H). MS: m/zꢀ
/
Yield: 0.28 g, 74%. Compound 2c: m.p. 194ꢃ
/
195 8C
106.1 (d, JSiꢁHꢀ348.34
335.5, ꢂ345.5, ꢂ350.2. H-
NMR (CDCl ): 2.15 (s, 12H), 2.33 (s, 12H), 2.70 (s, 6H),
2
9
(
dec.). Si-NMR (CDCl ): ꢂ
/
/
3.17. Photolysis of 3 in the presence of ethanol
3
15
1
Hz). N-NMR (CDCl ):ꢂ
/
/
/
3
3
A mixture of 3 (0.6 g, 0.85 mmol) and an excess of
ethanol (1 ml) in cyclohexane (5 ml) was irradiated for 4
h. By a procedure analogous to that described above
2
.88 (s, 6H), 3.39 (s, 4H), 3.56 (s, 4H), 4.14 (d, 2H, Jꢀ
/
1
(
5.07 Hz), 4.57 (d, 2H, Jꢀ15.07 Hz), 4.47 (s, 1H), 7.27
/
1
s, 4H). C-NMR (CDCl ): 43.81, 44.49, 45.31, 59.19,
3
3
formations,
Si)Si(H)OEt (20%), Me SiSiMe (7%) and Me SiOAr
(ArO) Si(H)OEt
2
(6%),
ArO(Me3-
5
CDCl , cm ): n
9.66, 62.28, 119.91, 129.83, 132.68, 149.68. IR (KBr,
ꢂ1
3
3
3
: 2206. MS (MNBA) FABꢁ
/0: m/
(23%) were characterized beside (ArO) Si(SiMe ) (68%)
2 3 2
3
SiꢁH
ꢁ
ꢂ
zꢀ
/
557 [(ArO) SiH] , FABB
/
0: m/zꢀ
/
80 [Br] . Anal.
and another unidentified product.
2
Calc. for C H N O BrSi (Mꢀ
/637.77): C, 56.50; H,
3
0
53
6
2
8
.38; N, 13.18. Found: C, 56.26; H, 8.14; N, 12.84%.
3.18. Thermolysis of 3 in the presence of 2,3-
dimethylbuta-1,3-diene
3
.15. Reaction of 2 with iodine
A mixture of 3 (0.36 g, 0.51 mmol) and an excess of
,3-dimethylbuta-1,3-diene was sealed in an evacuated
A solution of iodine (0.08 g, 0.32 mmol) in 5 ml of
2
ether was added dropwise, at 0 8C, to a solution of 2
0.36 g, 0.64 mmol) in 10 ml of ether. The resulting
mixture was stirred until evolution of H was ceased.
The precipitate formed was filtered and washed twice
with ether (10 ml) to give 2d (0.21 g, 48%) as a white
tube and heated at 120 8C for a week. After addition of
pentane (20 ml) to the mixture and elimination of
(
2
(ArO) Si(SiMe ) (63%) by precipitation at ꢂ
/
20 8C,
the analysis of the filtrate by H-NMR and GCꢃMS
reveals the formations of 1,1-diaryloxy-3,4-dimethyl-1-
silacyclopent-3-ene (ꢀ2%), 1-aryloxy-1-trimethylsilyl-
2
3 2
1
/
2
9
powder. Compound 2d: m.p. 204ꢃ
/
205 8C (dec.). Si-
/
15
NMR (CDCl ): ꢂ106.2 (d, JSiꢁHꢀ347 Hz). N-NMR
/
/
3
3,4-dimethyl-1-silacyclopent-3-ene (29%), Me Si- OAr
(32%) and Me SiSiMe (3%) beside another product
3
1
(
CDCl ): ꢂ
/
335.1, ꢂ
2H), 2.39 (s, 12H), 2.67 (s, 6H), 2.86 (s, 6H), 3.37 (s,
H), 3.68 (s, 4H), d ꢀ4.19 (2H) et d ꢀ4.48 (2H),
13.2 Hz, 7.31 (s, 4H). C-NMR (CDCl ): 43.93,
/
343.9, ꢂ
/
350.0. H (CDCl ): 2.12 (s,
3
3
3
3
1
unidentified.
4
JAB
/
/
A
B
ꢂ
ꢄ
/
2
13
1
ꢀ
/
ꢃ
/
(ArO)
(CDCl
2.22 (s, 24H), 3.37 (s, 4H), 3.51 (s,8H), 7.33 (s, 4H).
2
/
SiCH
2
C(CH
3
)ꢀ
/
C(CH
3
)C
H
2
:
H-NMR
3
4
1
4.73, 45.37, 59.22, 59.84, 62.29, 120.02, 127.99, 130.86,
ꢂ1
3
): 1.67 (s, 4H), 2.02 (s, 4H), 2.20 (s, 12H),
49.99. IR (KBr, CDCl , cm ): n
3
: 2212. MS:
SiꢁH
ꢁ
ꢁ
(
MNBA) FABꢁ
/
0: m/zꢀ
/
557 [(ArO) SiH] , FABB
/0:
MS: m/zꢀ
/
638 [M] .
ꢂ
2
ꢂ
ꢄ
/
3
m/zꢀ
84.77): C, 52.62; H, 7.80; N, 12.27. Found: C, 52.31;
H, 7.58; N, 12.39%.
/
127 [I] . Anal. Calc. for C H N O ISi (Mꢀ
/
1
3
0
53
6
2
ꢃ
/
(ArO)(Me Si)
3
/
SiCH C(CH )ꢀ
/C(CH )C
H :
2
H-
2
3
6
NMR (CDCl ): 0.23 (s, 9H), 1.63 (s, 6H), 2.03 (s,
3
4
4
H), 2.21 (s, 6H), 2.23 (s, 12H), 3.40 (s, 2H), 3.57 (s,
ꢁ
H), 7.3 (s, 2H). MS: m/zꢀ447 [M] .
/
3
.16. Thermolysis of 3 in the presence of ethanol
A mixture of 3 (0.50 g, 0.71 mmol) and an excess of
Crystal data for [(Me Si) SiO] : C H O Si , Mꢀ
/
3
2
3
18 54
3
9
˚
571.42, monoclinic, P2 /c, aꢀ
/
18.677(2) A, bꢀ
/
1
˚
˚
ethanol (1 ml) was sealed in an evacuated tube and
heated at 120 8C for 3 days. After addition of pentane
10.545(1) A, cꢀ
/
20.167(3) A, bꢀ
/
115.58(2)8, Vꢀ
4, r 1.059 Mg m , F(000)ꢀ
/
1248,
0.349
3
ꢂ3
˚
3582.6(7) A , Zꢀ
/
/
c
˚
(
obtained, and then filtered to give (ArO) Si(H)OEt
20 ml) to the mixture, a yellow precipitate was
lꢀ
/
0.71073 A, Tꢀ
/
173(2) K, m (Moꢃ
/
K )ꢀ
/
a
ꢂ1
mm , crystal size 0.4ꢄ0.3ꢄ0.2 mm, 2.28B
/
/
/
U B
/
2
1
(
ꢀ
/
2%). Analyses of the filtrate by H-NMR and GCꢃ
MS show the formation of Me SiSiMe (ꢀ2%), Me3-
SiOAr (33%), ArO(Me Si)Si(H)OEt (32%) and (Ar-
/
24.108, 4527 reflections (3530 independent) were col-
lected at low temperatures using an oil-coated shock-
cooled crystal on a STOE IPDS diffractometer. The
structure was solved by direct methods (SHELXS-97) [39]
and 289 parameters were refined using the least-squares
/
3
3
3
O) Si(SiMe ) (62%). After precipitation at ꢂ20 8C of
/
2
3 2
(
ArO) Si(SiMe ) all the volatiles were eliminated in
2 3 2
ꢂ3
2
vacuo (80ꢃ
/
82 8C/10
mmHg, 3 h) and ArO(Me3-
method on F [40]. All non-hydrogen atoms were refined

104
A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ105
/
Organomet. Chem. 574 (1999) 193;
c) K. Tamao, M. Asahara, T. Saeki, A. Toshimitsu, Angew.
anisotropically. The hydrogen atoms of the molecules
were geometrically idealized and refined using a riding
˚
model. Largest electron density residue: 0.247 e A , R1
(
Chem. Int. Ed. Engl. 38 (1999) 3316.
14] A. Akkari-El Ahdab, G. Rima, H. Gornitzka, J. Barrau, J.
ꢂ3
[
(
for I ꢁ
/
2s(I))ꢀ
/
0.0408 and wR ꢀ0.1051 (all data)
/
2
Organomet. Chem. 636 (2001) 96.
2
2 2
with R ꢀ
a w(F ) )
/
ajjF jꢂ
/
jF jj/ajF j and wR ꢀ
/
(a w(F ꢂ
/
F ) /
[15] A.G. Brook, S.C. Nyburg, F. Abdesaken, B. Guteskut, R.K.M.R
Kallury, Y.C. Poon, Y.-M. Ghang, W. Wong-Ng, J. Am. Chem.
Soc. 104 (1982) 5667.
1
2
o
c
o
2
o
c
2 0.5
.
o
[
16] (a) W. Clegg, Acta Crystallogr. Sect. B 38 (1982) 1648;
b) M. Veith, A. Rammo, Phosphorous, Sulfur Silicon 123 (1997)
5 and references cited herein.
(
7
4
. Supplementary material
Crystallographic data (excluding structure factors)
[
[
17] R.D. Miller, J. Michel, Chem. Rev. 89 (1989) 1359.
18] R.J.P. Corriu, G. Lanneau, M. Perrot, Tetrahedron Lett. 28
(
1987) 3941.
have been deposited with the Cambridge Crystallo-
graphic Data Centre as supplementary publication no.
CCDC-179386. Copies of the data can be obtained free
of charge on application to The Director, CCDC, 12
[
19] (a) U.-H. Berlekamp, P. Jutzi, A. Mix, B. Neumann, H.-G.
Stammler, W.W. Schoeller, Angew. Chem. 111 (1999) 2071;
(
b) U.-H. Berlekamp, P. Jutzi, A. Mix, B. Neumann, H.-G.
Stammler, W.W. Schoeller, Angew. Chem. Int. Ed. 38 (1999)
048.
2
Union Road, Cambridge CB2 1EZ, UK (Fax: ꢁ
/
44-
[20] J. Belzner, D. Sch a¨ r, B.O. Kneisel, R. Herbst-Irmer, Organome-
tallics 14 (1995) 1840.
1223-336033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
[21] (a) C. Chuit, R.J.P. Corriu, A. Mehdi, C. Reye, Angew. Chem.
05 (1993) 1372;
b) C. Chuit, R.J.P. Corriu, A. Mehdi, C. Reye, Angew. Chem.
1
(
Int. Ed. Engl. 32 (1993) 1311;
(c) F. Carre, C. Chuit, R.J.P. Corriu, A. Mehdi, C. Reye, Angew.
Chem. 106 (1994) 1152;
References
[
[
[
[
[
[
[
1] C. Chuit, R.J.P. Corriu, C. Reye, J.C. Young, Chem. Rev. 93
(d) F. Carre, C. Chuit, R.J.P. Corriu, A. Mehdi, C. Reye, Angew.
Chem. Int. Ed. Engl. 33 (1994) 1097;
(1993) 1371.
2] R.J.P. Corriu, J.C. Young, in: S. Patai, Z. Rappoport (Eds.), The
Silicon-Heteroatom Bond, Wiley, 1991.
(e) C. Breliere, R. Carre, R.J.P. Corriu, M. Wong Chi Man, J.
Chem. Soc. Chem. Commun. (1994) 2333.
3] T.J. Barton, S.A. Burns, P.P. Gaspar, Y.-S. Chen, Synth. React.
Inorg. Met.-Org. 13 (1983) 881.
[22] J. Belzner, D. Sch a¨ r, R. Herbst-Irmer, B.O. Kneisel, M. Nolte-
meyer, Tetrahedron Lett. 54 (1998) 8481.
4] P.P. Gaspar, Y.-S. Chen, A.P. Helfer, S. Konieczny, E.C.-L. Ma,
S.-H. Mo, J. Am. Chem. Soc. 103 (1981) 7344.
[23] J. Belzner, V. Ronneberger, D. Sch a¨ r, C. Br o¨ nnecki, R. Herbst-
Irmer, M. Noltemeyer, J. Organomet. Chem. 577 (1999) 330.
[24] D. Kost, I. Kalikhman, M. Raban, J. Am. Chem. Soc. 117 (1995)
11512.
5] H. Van e` ik, G. Raabe, M.J. Michalczyk, R. West, J. Michl, J. Am.
Chem. Soc. 107 (1985) 4097.
6] J. Braddock-Wilking, M.Y. Chiang, P.P. Gaspar, Organometal-
lics 12 (1993) 197.
[25] I. Kalikhman, S. Krivonos, D. Stalke, T. Kottke, D. Kost,
Organometallics 16 (1997) 3255.
7] M. Weidenbruch, P. Will, K. Peters, H.G. von Schnering, H.
Marsmann, J. Organomet. Chem. 521 (1996) 355.
8] G.R. Gillette, G. Noren, R. West, Organometallics 9 (1990) 2925.
9] (a) K. Tamao, Y. Tarao, Y. Nakagawa, K. Nagata et, Y. Ito,
Organometallics 12 (1993) 1113;
[26] (a) D. Kost, I. Kalikhman, S. Krivonos, D. Stalke, T. Kottke, J.
Am. Chem. Soc. 120 (1998) 4209;
[
[
(b) I. Kalikhman, V. Kingston, O. Girshberg, D. Kost, Organo-
metallics 20 (2001) 4713.
[27] (a) R.J.P. Corriu, G.F. Lanneau, C. Priou, Angew. Chem. 103
(1991) 1153;
(b) K. Tamao, M. Asahara, T. Saeki, A. Toshimitsu, J.
Organomet. Chem. 600 (2000) 118.
(b) R.J.P. Corriu, G.F. Lanneau, C. Priou, Angew. Chem. Int.
Ed. Engl. 30 (1991) 1130.
[
10] (a) R. Corriu, G. Lanneau, C. Priou, F. Soulairol, N. Auner, R.
Probst, R. Conlin, C. Tan, J. Organomet. Chem. 466 (1994) 55;
[28] (a) R. Probst, C. Leis, E. Herdtweck, C. Zybill, N. Auner, Angew.
Chem. 103 (1991) 1155;
(
b) R.J.P. Corriu, B.P.S. Chauhan, G.F. Lanneau, Organome-
tallics 14 (1995) 1646;
c) B.P.S. Chauhan, R.J.P. Corriu, G.F. Lanneau, C. Priou, N.
Auner, H. Handwerker, E. Herdtweck, Organometallics 14 (1995)
657.
(b) R. Probst, C. Leis, E. Herdtweck, C. Zybill, N. Auner, Angew.
Chem. Int. Ed. Engl. 30 (1991) 1132.
(
[29] R.J.P. Corriu, G. Lanneau, B.P.S. Chauhan, Organometallics 12
(1993) 2001.
1
[
11] (a) J. Belzner, in: N. Auner, J. Weis (Eds.), Organosilicon
Chemistry III: From Molecules to Materials, VCH, Weinheim,
[30] M. Weinmann, G. Rheinwald, L. Zsolnai, O. Walter, M.
B u¨ chner, B. Schiemenz, G. H u¨ ttner, H. Lang, Organometallics
17 (1998) 3299 (And references quoted therein).
[31] T.J. Marks, J. Am. Chem. Soc. 93 (1971) 7090.
[32] (a) A.R. Rossi, R. Hoffmann, Inorg. Chem. 14 (1975) 365;
(b) J.K. Burdett, Inorg. Chem. 15 (1976) 212.
1998, p. 58;
(b) J. Belzner, U. Dehnert, H. Ihmels, M. H u¨ bner, P. M u¨ ller, I.
Uson, Chem. Eur. J. 4 (1998) 852.
[
12] (a) K. Tamao, K. Nagata, M. Asahara, A. Kawachi, Y. Ito, M.
Shiro, J. Am. Chem. Soc. 117 (1995) 11592;
[33] (a) D. Agustin, G. Rima, H. Gornitzka, J. Barrau, Organome-
tallics 19 (2000) 4276 (And references quoted therein);
(b) D. Agustin, G. Rima, H. Gornitzka, J. Barrau, Inorg. Chem.
19 (2000) 5492.
(
b) K. Tamao, M. Asahara, T. Saeki, S.-G. Feng, A. Kawachi, A.
Toshimitsu, Chem. Lett. (2000) 660;
c) K. Tamao, M. Asahara, A. Toshimitsu, Chem. Lett. (2000)
58.
13] (a) K. Tamao, M. Asahara, A. Kawachi, J. Organomet. Chem.
21 (1996) 325;
b) K. Tamao, M. Asahara, G.-R. Sun, A. Kawachi, J.
(
6
[34] P. Arya, J. Boyer, F. Carre, R.J.P. Corriu, G. Lanneau, M.
Perrot, C. Priou, Angew. Chem. Int. Ed. Engl. 28 (1989) 1016.
[35] G. Van Koten, J.T.B.H. Jastrzebski, J.G. Noltes, A.L. Speck, J.C.
Schoone, J. Organomet. Chem. 184 (1978) 233.
[
5
(

A. Akkari-El Ahdab et al. / Journal of Organometallic Chemistry 658 (2002) 94ꢃ
/
105
105
[
36] H. Handwerker, C. Leis, R. Probst, P. Bissinger, A. Grohmann,
P. Kiprof, E. Herdweck, J. Bl u¨ mel, N. Auner, C. Zybill,
Organometallics 12 (1993) 2162.
[38] H. Suzuki, N. Tokitoh, R. Okazaki, S. Nagase, M. Goto, J. Am.
Chem. Soc. 120 (1998) 11096.
[39] G.M. Sheldrick, Acta Crystallogr. Sect. A 46 (1990) 467.
[40] SHELXL-97, Program for Crystal Structure Refinement, G.M.
Sheldrick, University of G o¨ ttingen, 1997.
[
37] (a) J. Barrau, G. Rima, T. El Amraoui, J. Organomet. Chem. 570
(
(
1998) 163;
b) D. Agustin, G. Rima, H. Gornitzka, J. Barrau, Main Group
Met. Chem. 22 (1999) 703.