Intramolecular O → Si donor-acceptor interaction in R 2P(=O)CH2CH2SiF3 molecules: Synthesis of dialkyl [2-(trifluorosilyl)ethyl]phosphonate and bis[(chloromethyl)dimethylsilyl] styrylphosphonate

Article abstract of DOI:10.1134/S1070363206100082

The reaction of diethyl [2-(triethoxysilyl)ethyl]phosphonate with boron trifluoride etherate was used to synthesize diethyl [2-(trifluorosilyl)ethyl] phosphonate. The reaction of bis(trimethylsilyl) styrylphosphonate with chloro(chloromethyl)dimethylsilane gave bis[(chloromethyl)dimethylsilyl] styrylphosphonate. Multinuclear ¹H, ¹³C, ¹⁹F, ²⁹Si, and ³¹P NMR spectroscopy established the absence of a P=O → Si coordination bond in these compounds and the four-coordinate state of the silicon atom. Evidence for this finding was obtained by B3LYP/6-31G(d) quantum-chemical calculations. However, the same calculations for R₂P(=O)? CH₂CH₂SiF₃ (R = Me, Me₂N) showed the presence in such molecules of an O → Si coordination bond both in the gas phase and in CHCl₃ solution. The distance between the O and Si atoms in this series molecules decreases with R in the order: MeO > Me > Me₂N. The axial Si-F bond length increases in the same order and parallels the order of the Hammet σ ₀ ^m constants of these substituents, relating to their interaction with π-electron systems. Nauka/Interperiodica 2006.

Full text of DOI:10.1134/S1070363206100082

ISSN 1070-3632, Russian Journal of General Chemistry, 2006, Vol. 76, No. 10, pp. 1554 1561.
Original Russian Text M.G. Voronkov, V.A. Pestunovich, N.F. Chernov, A.I. Albanov, E.F. Belogolova, L.V. Klyba, A.E. Pestunovich, 2006, published
in Zhurnal Obshchei Khimii, 2006, Vol. 76, No. 10, pp. 1621 1628.
Pleiades Publishing, Inc., 2006.
Intramolecular O Si Donor Acceptor Interaction
in R P(=O)CH CH SiF Molecules: Synthesis of Dialkyl
2
2
2
3
[
2-(Trifluorosilyl)ethyl]phosphonate
and Bis[(chloromethyl)dimethylsilyl] Styrylphosphonate
M. G. Voronkov, V. A. Pestunovich , N. F. Chernov, A. I. Albanov,
E. F. Belogolova, L. V. Klyba, and A. E. Pestunovich
Favorskii Institute of Chemistry, Siberian Branch, Russian Academy of Sciences,
ul. Favorskogo 1, Irkutsk, 664033 Russia
e-mail: voronkov@irioch.irk.ru
Received May 25, 2006
Abstract The reaction of diethyl [2-(triethoxysilyl)ethyl]phosphonate with boron trifluoride etherate was
used to synthesize diethyl [2-(trifluorosilyl)ethyl]phosphonate. The reaction of bis(trimethylsilyl) styrylphos-
phonate with chloro(chloromethyl)dimethylsilane gave bis[(chloromethyl)dimethylsilyl] styrylphosphonate.
1
13
19 29
31
Multinuclear H, C, F, Si, and P NMR spectroscopy established the absence of a P=O
Si coordina-
tion bond in these compounds and the four-coordinate state of the silicon atom. Evidence for this finding was
obtained by B3LYP/6-31G(d) quantum-chemical calculations. However, the same calculations for R P(=O)
2
CH CH SiF (R = Me, Me N) showed the presence in such molecules of an O
Si coordination bond both
2
2
3
2
in the gas phase and in CHCl solution. The distance between the O and Si atoms in this series molecules
3
decreases with R in the order: MeO > Me > Me N. The axial Si F bond length increases in the same order and
2
0
parallels the order of the Hammet
tron systems.
DOI: 10.1134/S1070363206100082
constants of these substituents, relating to their interaction with -elec-
m
Earlier we discovered a new class of intramolecular
complex compounds of five-coordinate silicon atom
of general formula I,
F
R R
N
F
F Si
H C
CH2
Y
2
R
C
CH2
II
O
Si
F
F
F
R = H, Me.
I
derivatives of acylamides, lactams, cyclic amides,
carbamide and acylhydrazines with chloro(chloro-
methyl)dimethylsilane afford (O Si) chelate N-
chlorodimethylsilylmethyl five-coordinate silicon
derivatives with coordination heterocycle V [6 10].
Such compounds are formed in three consecutive
steps: (1) persilylation reaction, (2) kinetically con-
trolled intramolecular O-silylmetylation of inter-
mediate III, and (3) thermodynamically controlled
unusual Chapmen rearrangement of the resulting
zwitter-ionic isoamide derivative IV into chelate
reaction product V [6 10].
R = alkyl, aryl, alkoxyl; Y = O, S, NR , CH ; R = H, Alk.
2
More recently we devoted to such compounds a
great number of publications which were mostly cited
in [2, 3]. This class of compounds can also be con-
sidered to include (N Si) (3-aminopropyl)trifluoro-
silane and its methyl derivatives [4, 5].
Furthermore, we established that N-trimethylsilyl
Deceased.
1554

INTRAMOLECULAR O Si DONOR ACCEPTOR INTERACTION
1555
Table 1. Parameters of the 1H NMR spectra of compounds XVI and Xb
EtOSi
EtOP
Comp. no.
SiCH2
CH2P
Me
CH O
Me
CH O
2
2
XVI
Xb
0.85 m
1.32 m
1.21 t
3.81 q
1.31 t
1.35 t
4.09 d.q
4.32 m
1.75 m
2.17 m
R1
R2
R1
O
R2
N
R1
O
R2
N
+
R1
O
R2
N
SiMe2
Me
1
2
3
Si
N
+ ClMe2SiCH2Cl
O
Cl
Me SiCl
Me
3
Si
SiMe3
Cl
Me
Cl
Me
III
IV
V
1
2
2
R , R = Alk, (CH ) , n = 3 5; R = NAlk , R = H, Alk.
2
n
2
Proceeding with these studies we set ourselves the
aim to synthesize chelate derivatives with a five-co-
ordinate silicon in which the latter is bonded with
phosphoryl group by a donor acceptor bond.
We studied the possibility of existence of an intra-
molecular P=O Si coordination bond.
(
RO) P(CH ) SiF
(EtO) PCH SiMeF
2
2 n
3
2
2
2
O
O
Our first attempt to prepare such a complex con-
taining an endocyclic P=O Si bond gave un un-
expected result [11]: The reaction of N,N,N ,N -tetra-
ethyl-N -tert-butylphosphoric triamide with BuLi and
then with (chloromethyl)dimethylsilane yielded a
cyclic five-coordinate silicon derivative containing an
endocyclic POSi group with the silicon atom co-
ordinated with Cl anion.
XI
R = Me, Et, n = 1 (IX); n = 2 (X), n = 2, R = Me (Xa),
R = Et (Xb), R = Me, Et (Xc).
Such compounds were synthesized by the follow-
ing scheme.
(
RO) P(CH ) Si(OR ) + F B OEt
2 2 n 3 3 2
N
CMe3
+
O
(
Et N) P
2 2
Cl
(
RO) P(CH ) SiF + B(OR ) + Et O.
(1)
2
2 n
3
3
2
O
Si
O
Me
X
Me
Compounds IX and XI (obtained by the same
procedure) proved to be unstable and could not be
isolated individual, because they decomposed on dis-
VI
First five-coordinate silicon compounds with a
P=O Si coordination bond (VII, VIII) were pre-
pared quite recently [12, 13].
tillation to form MeP(O)(OEt) (XII). Nevertheless,
2
1
they were identified in the reaction mixture by H,
1
2
29
31
C, Si, and P NMR and mass spectrometry. As
the decomposition products of difluoride XI we also
identified by the latter method (F MeSi) O and
O
EtO
P O
SiPh
P O
(i-PrO) P O
2
2
2
EtP(O)(OEt)2.
t-Bu
t-Bu
SiPh H
2
Phosphonate Xb was isolated individual as a color-
less liquid, bp 163 165 C (12 mm Hg). Its composi-
tion and structure are confirmed completely by ele-
mental analysis and multinuclear NMR (Tables 1
and 2).
(
i-PrO) P=O
2
EtO
EtO
VII
VIII
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 10 2006

1556
VORONKOV et al.
Table 2. Parameters of the 13C, 19F, 29Si and 31P NMR spectra of compounds XVIa and Xbb
Comp.
no.
EtOP
EtOSi
CH Si
CH2P
2
Si
F
P
Me
CH O
Me
CH O
2
2
XVI
Xb
2.24 d
0.98 d.q
16.14 d
15.65 d
61.17 d
66.91
17.93
58.22
18.50 d
16.00 d
47.33 d
61.2 q.d
33.89
137.61 33.21
a
2
3
2
1
3
b
Coupling constants for XVI: J
8.1, J
5.9, J
J
6.63, J
141.9, J
36.45 Hz. Couplinf constants
Si C C P
C C P
C C O P
C O P
C P
2
3
1
1
3
for Xb:
J
22.0,
J
5.5,
J
146,
277.5,
J
37.4 Hz.
C Si F
C C O P
C P
Si F
Si C C P
The Si, 31P, and 19F chemical shifts and 29Si 19
29
F
It is noteworthy that compound XVb is not the
and 29Si P coupling constants, as well as the in-
variability of the Si chemical shift in the tempera-
31
major reaction product. Simultaneously, (MeO) Si
3
2
9
CH CH P(O)(OMe)OEt (XVc) and (MeO) SiCH
2
2
3
2
ture range from 20 to +50 C (CDCl ) or from 25 to
CH P(O)(OMe) (XVa) are formed by alkoxyl ex-
3
2 2
7
0 C (CD C D ) attest the absence of intramolecular
change between phosphorus and silicon. According to
NMR and mass spectral data, the XVa:XVb:XVc
molar ratio is 1:1:2.
3
6
5
P=O Si interaction in Xb, or this interaction is very
weak.
Compounds Xc and IX have the same structure, as
We also studied the possibility of formation of
five-coordinate silicon compounds containing a
P=O Si bond in the reaction of ClCH SiMe Cl with
follows from their NMR chemical shifts: F SiCH2
3
CH P(O)(OMe)OEt (Xc):
60 ppm,
2
Si
F
2
2
2
1
34 ppm, JSi F 270.7 Hz; F SiCH P(O)(OEt)
3 2
earlier unknown bis(trimethylsilyl) styrylphosphonate
XVII). The latter compound was prepared by the
(
IX):
72.2 ppm,
146 ppm. These values
Si
F
(
are almost coincident with the chemical shifts of the
model four-coordinate compound ClCH SiF [14]:
reaction of styrylphosphonic acid with hexamethyldi-
silazane in the presence of a catalytic amount of
chlorotrimethylsilane.
2
3
7
1.3 ppm,
144 ppm, JSi F 267 Hz,
Si
F
thus providing further evidence for the absence of the
P=O Si coordination bond.
PhCH=CHP(OH) + (Me Si) NH
2
3
2
We failed to confirm the absence of the P=O Si
coordination bond in IX XI by IR spectroscopy, since
O
PhCH=CHP(OSiMe ) + NH .
(4)
3
2
3
absorption bans of the SiF groups in the range 700
3
1
000 cm 1 overlapped with the following absorption
O
XVII
bands: (P C) 765, (P O) 796, as(P O) 1160, and
s
1
(
P O C) 900 1100 cm [15].
Further persilylation of phosphonate XVII with
chloro(chloromethyl)dimethylsilane gave bis[(chloro-
methyl)dimethylsilyl] styrylphosphonate (XVIII).
This compound contains no P=O Si bond, and its
Precursors of compounds IX and XI were prepared
by the Arbuzov reaction [16].
R(EtO) SiCH X + P(OEt)
29
2
2
3
silicon atom is four-coordinate, as evidenced by Si
R(OEt) SiCH P(OEt) + EtX,
(2)
NMR data ( Si 14.20 ppm).
2
2
2
O
PhCH=CHP(OSiMe ) + 2ClCH SiMe Cl
3
2
2
2
Precursors of compounds Xa Xc were prepared
by the addition of diethyl hydrogen phosphite to the
corresponding vinyltrialkoxysilane in the presence of
AIBN.
O
PhCH=CHP(OSiMe CH Cl) .
(5)
2
2
2
O
XVIII
(
RO) SiCH=CH + (EtO) PH
3 2 2
Compound XVIII undergoes no changes on pro-
longed heating in boiling toluene or in nitrobenzene
at 80 C, as well as under microwave irradiation. To
reveal the possibility of formation of a P=O Si
coordination bond in compounds Xa and Xb and
related compounds XIX and XX (structures A or B),
O
(
RO) SiCH CH P(OEt) ,
(3)
3
2
2
2
O
R = Me (XVb), R = Et (XVI).
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 10 2006

INTRAMOLECULAR O Si DONOR ACCEPTOR INTERACTION
1557
we applied quantum-chemical calculations by the
B3LYP/6-31G(d) method.
Table 3. Selected structural and spectral characteristics
and relative energetics of coordinated (A) and noncoordi-
nated (B) forms of Xa molecule in gas phase and in
R
R
R
R
CHCl solution
3
P
P
O
O
A
B
Fe
Fe
Form
Si
F
Si
vacuum CHCl3 vacuum
5.108
CHCl3
Fa
F
F
Si O,
Si Fa,
5.117
1.599
1.599
1.598
111.6
111.9
A
B
2.917
1.605
1.603
1.591
3.176
1.604
1.596
1.596
1.597
1.595
Si F (1),
e
R = OEt (Xb), OMe (Xa), NMe (XIX), Me (XX).
Si F (2),
2
e
C Si F (1), deg
1.599 111.1
114.0 111.5
172.8
0.470
e
The positive sign and the value of the experimen-
C Si F (2), deg 117.0
e
tally measured 29Si coordination shift in Xb,
=
O Si F , deg
179.2
0.453
Si
a
a
Si(Xb)
(ClCH SiF ) = 10.1 ppm, provide in-
Si
2 3
Si,
0.584
0.595
57.8
179.0
0.0
0.0
0.0
59.1
13.5
direct evidence for the absence of Si O coordination
O P C C, deg
P C C Si, deg
20.3
63.0
0.1
57.8
57.7
0.6
56.2
179.3
0.0
bonding in this molecule in CDCl solution. This con-
3
1
b
b
b
clusion is confirmed by quantum-chemical calcula-
tions which show that in structure A of Xa, where the
oxygen lone pair is directed to the silicon atom, the
distance between O and Si is 2.917 in the gas phase
E, kcal mol
H, kcal mol 1
0.2
0.5
0.0
1
G, kcal mol
1.9
1.6
0.0
c
Si, ppm
63.0
9.6
60.4
12.2
59.0
13.6
, ppmd
and 3.176
only slightly shorter then the sum of the van der
Waals radii of the oxygen and silicon atoms (3.62
in CHCl solution. These distances are
3
Si
)
a
Deviation of the silicon atom from the plane defined by three
and much longer than the O Si bond length in alkoxy-
silanes (1.63 ) [17]. The axial Si F bond length in
form A of Xa is close to the equatorial bond lengths
and to the Si F distance in noncoodinated form B
b
equatorial fluorine atoms. The energy in form B is taken
c
equal to be zero.
d
The
of Xa was measured against
Si
internal TMS. Coordination shift defined as a difference of
the
vales of Xa and the model compound ClCH SiF .
2 3
Si
2
9
(
Table 3). The calculated Si chemical shifts
in
Si
Xa and coordination shifts for structures A and
Si
same time, in CHCl solution the coordinated form
3
B differ insignificantly and are close to experimental
values for Xb. The small upfield shift ( 4 ppm) of
the silicon signal in structure A with respect to that in
B can point to a very weak electrostatic interaction
between the O and Si atoms in the coordinated form
of Xa. Structures Xa and Xb are practically equal in
energy. Inclusion of entropy factors results in further
of XIX is preferred over noncoordinated by more than
1
2
kcal mol . The P=O Si bond in solution is found
to be 0.192 shorter than in the gas phase, the axial
Si F bond is 0.024
enhances by 9 ppm.
longer, and silicon shielding
The calculated O Si and axial Si F bond lengths
in dimethyl[1-(trifluorosilyl)ethyl]phosphine oxide in
the gas phase are 2.268 and 1.626 , respectively. In
CHCl3 solution, the Si O bond is shortened to
stabilization of the noncoodinated form (by 1.6
1
1
.9 kcal mol ).
1
.994 and Si F is elongated to 1.657 A. In isolated
XX molecules, the chelate (A) and noncoordinated
B) forms are in equilibrium. In CHCl solution, this
Replacement of two methoxy groups on phos-
phorus in Xa by the more electron-donor Me N
2
(
groups significantly shortens the distance between Si
and O (to 2.177 ). Therewith, the axial Si F bond is
3
equilibrium is shifted to form A. Inclusion of entropy
factors in chloroform makes form A preferred over
form B by 1.1 kcal mol .
elongated by 0.28
and the deviation of the silicon
1
atom from the plane of three equatorial fluorine atoms
( Si) is diminished by 0.238 . The coordination shift
The calculated distances between the oxygen and
silicon atoms in Xa, XIX, and XX are 2.917, 2.177,
and 2.268 , respectively. In the R P(O)CH CH SiF
in chelate form A of XIX in the gas phase is
Si
1
7.3 ppm. In whole, the structural and spectral par-
2
2
2
3
ameters of molecule XIX in coordinated form A show
the existence of a P=O Si coordination bond. These
data point to equilibrium between the coordinated and
noncoordinated forms of XIX in the gas phase. At the
series, this distance decreases with R in the order
0
m
(
parenthesized are the
values of the
substituents): MeO (0.06) > Me ( 0.07) > Me N
2
(
0.12). The axial Si F bond length in Xa, XX,
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 10 2006

1558
VORONKOV et al.
and XIX increases in the same order (1.605, 1.626,
OSi), 1.31 t (6H, CH CH OP), 4.08 · (4H, CH CH
3 2 3 2
and 1.885 , respectively) and parallels the order of
OP). 13C NMR spectrum, , ppm: 10.1 d (PCH Si,
C 2
0
m
the Hammet
constants of these substituents, relat-
JC P 131.5 Hz), 17.88 (CH CH OSi), 58.64 (CH CH
3 2 3
2
ing to their interaction with -electron systems (in our
case, the >P=O group).
OSi), 16.7 (CH CH OP), 61.22 d (CH CH OP, J
3 2 3 2 PC
6
.13 Hz). 29Si NMR spectrum:
NMR spectrum: 30.45 ppm.
54.9 ppm. 31P
Si
P
EXPERIMENTAL
Diethyl [(diethoxy)methylsilyl]methylphospho-
nate (XIV) was prepared similarly, yield 36%, bp
The mass spectra were registered on a Shimadzu
QP5050A GC MS instrument (SPB-5MS column,
length 60 m, internal diameter 250 nm, film thickness
20
1
50 151 C (18 mm Hg), nD 1.4277. Published data
20
1
[
16]: bp 99 99.5 C (1 mm Hg), nD 1.4277. H NMR
spectrum, , ppm: 1.30 d (2H, PCH Si, J H
2
2
PC
0
.25 nm; injector temperature 220 C, carrier gas
1
22.38 Hz), 0.30 s (3H, MeSi), 1.21 t (6H, CH CH
3 2
helium, flow rate 0.7 ml min , programmed tempera-
ture at a rate of 10 deg min ; electron energy 70 eV;
3
1
OSi, J 7.02 Hz), 3.79 q (4H, CH CH OSi), 1.31 t
3 2
3
(
6H, CH CH OP, J 7.17 Hz), 4.08 d.q (4H, CH C
3 2 3
ion source temperature 200 C; detected mass range
3
13
H OP, J
2.54 d (PCH Si, J
4.6 Hz). C NMR spectrum, C, ppm:
129.97 Hz), 3.80 (MeSi),
7.96 (CH CH OSi), 58.20 (CH CH OSi), 16.13 d
2
P H
3
4-650 D; total ion monitoring).
1
1
1
2
C P
The IR spectra were registered on a Specord IR-75
spectrophotometer for thin films and KBr pellets.
3
2
3
2
3
(
CH CH OP,
JC P 6.13 Hz). Si NMR spectrum:
J
6.52 Hz), 61.03 (CH CH OP,
3
2
C P
29
3 2
2
13.6 ppm.
Si
The NMR spectra were registered on a Bruker
DPX-400 instrument for 5 10% CDCl3 solutions
against internal HMDS.
Diethyl [2-(triethoxysilyl)ethyl]phosphonate
XVI). Triethoxy(vinyl)silane, 5.4 g (0.03 mol) and
.12 g of AIBN were added with stirring to 8.3 g
0.06 mol) of diethyl hydrogen phosphite at 120 C.
(
0
(
All calculations were performed with full geometry
optimization on a B3LYP/6-31G(d) level of theory
using Gaussian-03 [18]. Correspondence of the result-
ing structures to potential energy minima was con-
firmed by positive values of the corresponding
Hessians. Medium effects were included in the frame-
work of the Tomasi polarized continuum model [19].
The reaction mixture was heated at the same tempera-
ture for an additional 1 h. Yield 3.73 g (38%), bp 186
1
88 C (6 mm Hg), n2 1.4216. Published data [21]:
5
D
2
5
bp 141 C (2 mm Hg), n 1.4216. The NMR spectral
D
data are listed in Tables 1 and 2. Mass spectrum, m/e
+
(
I , %): 328 ([M] , 7), 300 (53), 283 (33), 282 (23),
rel
The total energies of the structures (E) are cor-
rected for zero-point vibration energy (ZPE). The
enthalpies (H) and Gibbs energies (G) were calculated
for standard conditions (298.15 K, 1 atm). The ZPE,
H, and G values were not scaled.
255 (56), 254 (10), 238 (15), 227 (100), 226 (12), 210
(18), 199 (66), 182 (11), 171 (26), 163 (25), 153 (25),
143 (13), 125 (50), 119 (25), 109 (10), 91 (13), 81
(10), 79 (42), 63 (22), 62 (13), 45 (28).
Reaction of trimethoxy(vinyl)silane with diethyl
hydrogen phosphite (XVa XVc). A mixture of
20.7 g (0.14 mol) of (MeO) SiCH=CH and 0.26 g
The magnetic properties were calculated by the
B3LYP/6-311++G(2d,p) procedure for the B3LYP/6-
3
2
3
1G(d) geometry using the GIAO approach [20].
(0.0016 mol) of AIBN was added dropwise to 20.1 g
0.14 mol) of (EtO) P(O)H at 120 C. The reaction
(
2
The starting compounds for the synthesis of diethyl
mixture was heated at the same temperature for an
additional 4 h. Vacuum distillation gave 4.0 g of a
fraction boiling at 174 176 C (6 mm Hg). According
to NMR and mass spectral data, it contains (MeO)3
SiCH CH P(O)(OMe)OEt (XVc), (MeO) SiCH CH
(
[
trifluorosilyl)methylphosphonate (IX) and diethyl
difluoro(methyl)silyl]methylphosphonate (XI) were
diethyl (triethoxysilyl)methylphosphonate (XIII) and
diethyl [diethoxy)methylsilyl]methylphosphonate
2
2
3
2
2
(XIV), respectively.
P(O)(OMe) (XVa), and (MeO) SiCH CH P(O)(OEt)
2
3
2
2
2
Diethyl (triethoxysilyl)methylphosphonate
XIII). A mixture of 10.7 g (0.06 mol) triethyl phos-
(XVb) in a 2:1:1 molar ratio. Correspondingly, its
elemental composition obeys to empirical formula
C H O PSi. Found, %: H 8.29; Si 10.05; P 10.82.
(
phite and 27.0 g (0.13 mol) of (chloromethyl)triethoxy-
silane was heated for 1 h at 157 196 C. Vacuum dis-
tillation gave 6 g (32%) of compound XIII, bp 120
8
21
6
C H O PSi. Calculated, %: H 7.77; Si 10.31; P 11.38.
8
21
6
1
H NMR spectrum, , ppm: 3.73 (MeOSi), 0.86
CH Si), 1.74 (PCH ), 1.30 (CH CH OP), 4.08
2
5
(
(
1
22 C (4 mm Hg), n 1.4200. Published data [16]:
2
2
3
2
D
1
3
2
0
1
CH CH OP), 3.79 (POMe). C NMR spectrum, C,
bp 96.5 97 C (2 mm Hg), n 1.4234. H NMR spec-
3
2
D
2
2
ppm: 50.6 (MeOSi), 1.39 d (CH Si), 18 t (PCH , J
7.67 Hz), 16 d (CH CH OP, J
trum, , ppm: 1.31 d (PCH Si, J
24 Hz), 1.23 t
2
2
C P
2
H P
3
3
(
9H, CH CH OSi, J 6.8 Hz), 3.87 q (6H, CH CH
5.75 Hz), 61.04
3
2
3
2
3
2
C P
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 10 2006

INTRAMOLECULAR O Si DONOR ACCEPTOR INTERACTION
1559
(
CH CH OP, J
6.13 Hz). 29Si NMR spectrum:
Si
Diethyl [2-(trifluorosilyl)ethyl]phosphonate
Xb). Compound XVI, 3 g (0.009 mol), and 2.9 g
0.02 mol) of F B OEt was heated with distilling off
low-boiling compounds. The residue was distilled in a
vacuum to isolate 1 g (44.4%) of compound Xb, bp
3
2
P C
3
1
(
(
4
5 ppm. P NMR spectrum: P: 33.5 ppm.
3
2
Compound XVa, mass spectrum, m/e (I , %):
rel
+
2
2
58 ([M] , 59), 241 (15), 231 (32), 227 (40), 214 (18),
13 (55), 210 (25), 203 (18), 201 (13), 200 (15), 199
163 165 C (12 mm Hg). Found, %: H 5.24; P 12.82;
(
100), 198 (24), 185 (61), 184 (13), 182 (24), 172 (13),
71 (31), 170 (29), 154 (26), 153 (69), 140 (23), 139
36), 135 (21), 123 (17), 121 (34), 109 (19), 107 (27),
Si 11.59. C H O PF Si. Calculated, %: H 5.64; P
6
14
3
3
1
(
1
2.39; Si 11.22. The NMR spectral data are listed in
Tables 1 and 2.
9
8
5 (11), 93 (13), 91 (60), 90 (15), 83 (15), 82 (16),
1 (13), 79 (13), 77 (42), 65 (14), 63 (12), 61 (24), 60
Reaction of compounds XVa XVc with boron
(
(
12), 59 (27), 57 (11), 55 (13), 47 (24), 45 (27), 44
16), 43 (19), 41 (18).
trifluoride etherate.
compounds XVa XVc, 1.34 g (0.005 mol), and
.71 g (0.005 mol) of boron trifluoride etherate was
A
1:1:2 mixture of
0
Compound XVb, mass spectrum, m/e (I , %):
rel
+
heated under reflux for 1.5 h. Low-boiling com-
pounds were removed by distillation to isolate 0.8 g
of a mixture of compounds Xa Xc with the empirical
formula C H F O PSi. Found, %: H 5.61; F 24.10;
2
72 ([M] , 53), 255 (22), 241 (17), 227 (52), 213 (39),
1
99 (100), 185 (45), 171 (27), 153 (34), 139 (35), 135
(31), 125 (11), 109 (19), 107 (24), 93 (16), 91 (28),
8
2 (12), 81 (14), 77 (52), 59 (20), 47 (11), 45 (21), 44
5
12
3
3
P 12.98. C H F O PSi. Calculated, %: H 5.12; F
(12), 43 (16), 41 (14).
5
12
3
3
2
4.10; P 13.12.
Compound XVc, mass spectrum, m/e (I , %): 286
rel
+
The NMR spectrum of the product obviously re-
(
[M] , 61), 270 (12), 269 (34), 268 (20), 259 (12),
1
lates to compound Xc. H NMR spectrum, , ppm:
.13 (CH Si), 1.80 (PCH ), 1.28 (CH CH OP), 4.08
2
58 (12), 255 (11), 242 (19), 241 (70), 231 (12), 227
24), 224 (15), 214 (11), 213 (100), 210 (25), 203 (11),
99 (30), 196 (13), 185 (97), 184 (13), 173 (12), 171
11), 168 (11), 167 (33), 157 (29), 153 (13), 149 (28),
39 (53), 125 (25), 121 (17), 111 (15), 109 (28), 105
1
(
1
(
1
2
2
3
2
1
3
(CH CH OP), 3.76 (P OMe). C NMR spectrum, C,
3 2
ppm: 0 86 (CH Si), 18 (PCH ), 16 (CH CH OP), 61.5
2
2
3
2
2
9
19
(CH CH OP). Si NMR spectrum:
NMR spectrum:
60 ppm.
F
3
2
Si
(25), 93 (33), 91 (12), 83 (13), 82 (12), 81 (17), 79
(18), 77 (31), 76 (12), 65 (14), 63 (41), 59 (18), 57
(11), 55 (17), 47 (14), 45 (38), 44 (24), 43 (19), 41
(16).
134 ppm. 31P NMR specrum:
F
P
31.5 ppm (JSi F 270.7 Hz).
Diethyl [difluoro(methyl)silyl]methylphospho-
nate (XI). A solution of 0.7 g (0.002 mol) of com-
pound XIV and 0.5 g (0.003 mol) of BF OEt in
Diethyl (trifluorosilyl)methylphosphonate (IX).
3
2
A mixture of 2.3 g (0.007 mol) of compound XIII
and 1.5 g (0.01 mol) of BF OEt was heated under
reflux for 3.5 h. Volatile components were removed
by distillation to leave 1 g of a viscous liquid which,
according to elemental analysis and multinuclear NMR
spectroscopy, is compound IX. Found, %: C 25.35; P
1
1
4
1
.5 ml of benzene was heated under reflux for 1.5 h.
3
2
Volatile components were removed by distillation to
isolate 0.2 g of compound XI. Found, %: P 10.45.
1
C H F O PSi. Calculated, %: P 10.19. H NMR
6
15
2
3
spectrum, , ppm: 1.29 (CH CH OP), 4.23 (CH
3
2
3
13
31
CH OP).
C NMR spectrum, C, ppm: 12.20
2
2.89. C H F O PSi. Calculated, %: C 25.42; P
5 12 3 3
(PCH Si). P NMR spectrum, P, ppm: 36.32. We
1
2
0.60. H NMR spectrum, , ppm: 1.39 (CH CH OP),
29
3
2
failed to accumulate the Si signal.
1
3
.32 (CH CH OP), 2.13 (SiCH P). C NMR spec-
3 2 2
When injected to the chromatograph, compound
XI decomposed. The chromatogram contained peaks
of three compounds with the relative contents 91, 6,
and 2%. By mass spectral library search the main
component ( = 9.7 min) was identified as diethyl
trum,
, ppm: 13 (SiCH P), 15.74 (CH CH OP),
2 3 2
C
2
9
6
7
7.36 (CH CH OP).
2.2 ppm. P NMR spectrum:
Si NMR spectrum:
3
2
Si
F
3
1
19
36.4 ppm.
P
NMR spectrum:
146 ppm [JSi F 254.4 Hz].
F
Vacuum distillation of this residue yielded as little
as 0.2 g of diethyl methylphosphonate (XII), bp 86 C
methylphosphonate (SI:97) and the second (
=
11.6 min), as diethyl ethylphosphonate (SI:93). The
(
3 mm Hg). Found, %: C 39.30; H 8.53; P 19.87.
third component ( = 13.5 min) obviously is 1,3-di-
methyltetrafluorodisiloxane; its main characteristic
C H O P. Calculated, %: C 39.46, H 8.60; P 20.37.
5
13
3
1
H NMR spectrum, , ppm: 1.33 (CH ), 1.31 (CH
+
3
3
peak in the mass spectrum is at m/e 159 [M F] .
1
3
CH O, J
17.46 Hz). C NMR spectrum, C, ppm:
2
P H
1
Bis(trimethylsilyl) styrylphosphonate (XVII).
A mixture of 1.3 g (0.007 mol) of styrylphosphonic
acid, 2.3 g (0.014 mol) of hexamethyldisilazane, and
a catalytic amount of chlorotrimethylsilane was heated
3
2
2
3
31
JC P 6.13 Hz). P NMR spectrum:
spectrum, , cm : 765 (P C), 796 s(P O), 1160
as(P O), P=O (1230), 900 1100 (P O C).
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 10 2006

1560
VORONKOV et al.
for 3 h under reflux. Unreacted starting materials were
removed by distillation to isolate 1.7 g (74%) of a
Chipanina, N.N., Sherstyannikova, L.V., and Pestu-
novich, V.A., Dokl. Akad. Nauk, 2002, vol. 386,
no. 2, p. 203.
2
0
liquid compound XVII, n 1.4950. Found, %: C
D
5
0.89; H 7.94; P 8.94. C H O PSi . Calculated, %:
14 25 3 2
5. Chernov, N.F., Bolgova, Yu.I., Trofimova, O.M.,
Albanov, A.I., Chipanina, N.N., Pestunovich, V.A.,
and Voronkov, M.G., Dokl. Akad. Nauk, 2000,
vol. 375, no. 2, p. 210.
1
C 51.18; H 7.67; P 9.44. H NMR spectrum, , ppm:
2
0
7
.29 s (SiMe ), 6.29 t (CHP, J
JP H 17.67 Hz),
3
3
.35 d.d (PhCH=, J
6.0 Hz), 7.45 m (H ), 7.35 m
P H
o
1
3
(Hm,p). C NMR spectrum, C, ppm: 0.73 (MeSi),
6. Voronkov, M.G., Pestunovich, V.A., and Bau-
1
1
17.95 d (PCH=, JC P 199.14 Hz), 127.17, 128.52
kov, Yu.I., Metalloorg. Khim., 1991, vol. 4, p. 1210.
3
(Co,m), 129.50 (C ), 134.97 d (C , JC P 24 Hz),
p
i
7. Kost, D. and Kalikhman, I., The Chemistry of Organic
Silicon Compounds, Rappoport, Z. and Apeloig, Y.,
Eds., New York: Wiley, 1998, vol. 2, p. 1339.
1
45.34 d (PhCH=, 2J
6.47 Hz). 29Si NMR spec-
C P
2
31
trum:
20.84 ppm ( J 6.32 Hz). P NMR spec=
Si
sip
1
trum: 0.96 ppm. IR spectrum, , cm : 850 (SiMe ),
9
8. Voronkov, M.G., Pestunovich, A.E., Albanov, A.I.,
Vlasova, N.N., and Pestunovich, V.A., Izv. Akad.
Nauk SSSR., Ser. Khim., 1989, p. 2841.
P
3
90 (SiOP), 1220, 1250 (P=O).
Bis[(chloromethyl)dimethylsilyl)] styrylphos-
9
. Voronkov, M.G., Pestunovich, A.E., Albanov, A.I.,
phonate (XVIII). A mixture of 2.5 g (0.008 mol) of
phosphonate XVIII, 2.9 g (0.02 mol) of chloro(chlo-
romethyl)dimethylsilane and 5 ml of toluene was
heated under reflux for 20 h. Toluene was distilled
off to isolate a liquid compound XVIII, n 1.4640.
Found, %: Cl 17.87; Si 13.64; P 7.53. C H Cl O
Klyba, L.V., and Pestunovich, V.A., Zh. Org. Khim.,
2
003, vol. 39, no. 10, p. 1573.
10. Pogozhikh, S.A., Ovchinnikov, Yu.E., Kramaro-
va, E.P., Negrebetskii, Vad.V., Shipov, A.G., Alba-
nov, A.I., Voronkov, M.G., Pestunovich, V.A., and
Baukov, Yu.I., Zh. Obshch. Khim., 2004, vol. 74,
no. 10, p. 1617.
2
0
D
1
4
23
2
3
1
PSi . Calculated, %: Cl 17.84; Si 14.14; P 7.80. H
NMR spectrum, , ppm: 0.42 s (MeSi), 2.92 s
2
2
3
(CH Cl), 6.31 t (PCH=, J
JP H 18 Hz), 7.45
11. Albanov, A.I., Kudyakov, N.M., Pestunovich, V.A.,
Voronkov, M.G., Macharashvili, A.A., and Shklo-
ver, V.E., Metalloorg. Khim., 1991, vol. 4, no. 6,
p. 1228.
2
P H
1
3
7
.35 m (PhCH=). C NMR spectrum, C, ppm: 2.55
1
(
MeSi), 28.84 (CH ), 116.30 (PCH=, J
200 Hz),
2
C P
3
1
2
28.49, 127.24 (Co,m), 129.75 (C ), 130.50 (C , J
4.14 Hz), 146.51 (PhCH=, J
p
i
C P
2
29
6.0 Hz). Si NMR
12. Peveling, K., Henn, M., Low, C., Mehring, M.,
Schurmann, M., Costisella, B., and Jurrkschat, K.,
Organometallics, 2004, vol. 23, p. 1501.
C P
2
31
spectrum:
spectrum:
14.20 ppm ( J 5.83 Hz). P NMR
Si
P
sip
2.36 ppm.
1
3. Dannapel, K., Schurmann, M., Costisella, B., and
ACKNOWLEDGMENTS
Jurkschat, K., Organometallics, 2005, vol. 24, p. 1031.
1
4. Albanov, A.I., Gubanova, L.I., Larin, M.F., Pestu-
novich, V.A., and Voronkov, M.G., J. Organomet.
Chem., 1983, vol. 244, p. 5.
The authors are grateful to V.F. Sidorkin for help.
The work was financially supported by the Russian
Foundation for Basic Research (project no. 04-03-
2673) and Council for Grants of the President of the
15. Purdela, D. and Vilceanu, R., Chimia Compulsor
Organici ai Fosforului si ai Acizilor lui, Bucharest:
Acad. Rep. Soc. Romania, 1965. Translated under the
title Khimiya organicheskikh soedinenii fosfora,
Kabachnik, M.I., Ed., Moscow: Khimiya, 1972,
p. 535.
3
Russian Federation (grant no. NSh-4575-2006.3).
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RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 10 2006

INTRAMOLECULAR O Si DONOR ACCEPTOR INTERACTION
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