22
FROLOVA et al.
It should be noted that the addition of BPFPPA to burg) were used as deuterated solvents for NMR withꢀ
2
out additional purification.
trisubstituted alkenes Vb
–
Vc leads to formation of
two asymmetrical carbon atoms. It was found unexꢀ
pectedly that the diastereomeric composition of
resulting phosphine oxides VIb and VIc differs draꢀ
matically. Thus, according to 31P{1H} NMR spectra,
2ꢀVinylpyridine I (97%, Acros) was purified by disꢀ
tillation, and 1,4ꢀbenzoquinone VII (98%, Acros) was
recrystallized from hexane.
Synthesis of initial compounds. BPFPPA [5], (E)ꢀ
1ꢀ(4ꢀmethoxyphenyl)ꢀ3ꢀphenylpropꢀ2ꢀenꢀ1ꢀone III
[8], (4ꢀmethoxybenzylidene)malonodinitrile Va [9],
ethyl
3ꢀ[bis(pentafluorophenyl)phosphoryl]ꢀ3ꢀ(4ꢀ
methoxyphenyl)ꢀ2ꢀcyanopropionate VIb forms as a
statistical (i.e., 1 : 1) mixture of two diastereomers. On
the contrary, the formation of the corresponding
amide VIc occurs stereospecifically and, according to
1H and 31P{1H} NMR spectra, the compound is an
individual diastereomer. To determine its stereochemꢀ
istry, we performed Xꢀray diffraction study; it showed
that phosphine oxide VIc crystallizes as a solvate with
two chloroform molecules (space group Pꢀ1). On this
basis, one can determine only relative configuration of
both asymmetric centers, which proved to be
ethyl ester Vb [9], (
cyanoacrylamide Vc [9], and
IXc [10] were obtained by the known procedures.
E
)ꢀ3ꢀ(4ꢀmethoxyphenyl)ꢀ2ꢀ
N
ꢀarylmaleimides IXa
–
All studied reactions were monitored by 31P{1H}
NMR. The end of the reaction was detected by the disꢀ
appearance of the signal of initial BPFPPA in the
reaction mixture.
Elemental analyses were performed in the Laboraꢀ
tory of Microanalysis, Nesmeyanov Institute of Orgaꢀ
noelement Compounds, RAS.
(
2RS,3SR) (see Fig. 2).
Thus, the addition of BPFPPA to compounds with
Addition of BPFPPA to unsaturated compounds
(general procedure). A solution of an unsaturated
compound (1 mmol) in a minimal amount of chloroꢀ
activated C=C bonds is highly chemoꢀ, regioꢀ, and (in
some instances) stereoselective and provides a simple
and convenient approach to the targetꢀdirected design
of fluorineꢀcontaining organophosphorus compounds
form (2ꢀvinylpyridine
I was added without solvent)
was added to a solution of 0.38 g (1 mmol) of BPFPPA
in 5 mL of chloroform, heated under reflux until the
disappearance of BPFPPA in the reaction mixture, the
solvent was removed, and the residue was recrystalꢀ
lized from an appropriate solvent (see Table 1).
of new type, tertiary
phine oxides.
P,Pꢀbis(pentafluorophenyl)phosꢀ
EXPERIMENTAL
The crystals of compounds II and VIc suitable for
Xꢀray diffraction were obtained by isothermal evapoꢀ
ration at ambient temperature of solutions of the comꢀ
pounds in diethyl ether–hexane mixture (1 : 1) and
chloroform, respectively.
1
1H, H{31P}, and 31P{1H} NMR spectra of the
obtained compounds were recorded on a Bruker
AVꢀ300 spectrometer (operating at 300.13 MHz for
1H and 1H{31P} and at 121.49 MHz for 31P{1H}) and a
Bruker AVꢀ400 spectrometer (operating at 400.13 MHz
1
1
for H and H{31P} and at 161.98 MHz for 31P{1H}).
The signals of residual protons of the deuterated solꢀ
vent were used as an internal reference, 85% H3PO4
ACKNOWLEDGMENTS
This work was supported by the Russian Foundaꢀ
tion for Basic Research (project nos. 08–03–00586–a
and 08–03–12153–ofi) and the Presidium of the Rusꢀ
sian Academy of Sciences (Program no. 18: Developꢀ
ment of Methods for Preparing Chemical Substances
and Design of Novel Materials).
was used as an external reference for 31P{1H} NMR
spectra.
Xꢀray diffraction studies of compounds II and VIc
were carried out on a SMART APEX 1000 CCD difꢀ
fractometer (Mo
K radiation, graphite monochromaꢀ
α
tor,
ω
scanning). The structures were solved by direct
REFERENCES
methods and refined by fullꢀmatrix least squares in the
anisotropic approximation on Fh2kl . Hydrogen atoms
were located from difference Fourier syntheses of
electron density and refined in the isotropic approxiꢀ
mation using the riding model. The main crystalloꢀ
graphic data and refinement parameters are shown in
Table 2. All calculations were made using SHELXTL
PLUS software package.
1. Nifant’ev, E.E., Khimiya gidrofosforil’nykh soedinenii
(Chemistry of Hydrophosphoryl Compounds), Mosꢀ
cow: Nauka, 1983.
2. Griffiths, J.E. and Burg, A.B., J. Am. Chem. Soc., 1960,
vol. 82, no. 6, pp. 1507–1508.
3. Griffiths, J.E. and Burg, A.B., J. Am. Chem. Soc., 1962,
vol. 84, no. 18, pp. 3442–3450.
4. Dobbie, R.S. and Straughan, B.P., Spectrochim. Acta A
1971, vol. 27, no. 2, pp. 255–260.
,
Chloroformꢀ
d
and dimethyl sulfoxideꢀdI
(“Prikladnaya khimiya” Research Center, St. Petersꢀ
5. Magnelli, D.D., Tesi, G., Lowe, J.U., and
McQuistion, W.E., Inorg. Chem., 1966, vol. 5, no. 3,
pp. 457–461.
2
According to [9], both alkenes have the (E) configuration.
DOKLADY CHEMISTRY Vol. 430
Part 1
2010
Frolova
