close

Вход

Забыли?

вход по аккаунту

?

New Type of Reaction Resulting from the Action of O2 on Diarylperfluoroacylphosphanes.

код для вставкиСкачать
mentioned conditions the concentration of OF amounts
to ca. lo-'' mol c ~ r - ~ .
The same results for the reaction with 0, are obtained by
using F atoms produced in a microwave discharge in a
mixture of CF, and He. However, when the F atoms are
produced by reaction of NF, with an excess of N atoms,
the maximal concentration of OF is very much lower, as
also is the consumption of F atoms at the beginning of
the reaction. It can be assumed that OF is here consumed
by the rapid subsequent reaction :
cyclohexane. The compositions and structures of the new
I-(diarylphosphory1)lH-perfluoroalkyl diarylphosphinates
(7aj to ( 7 e ) follow from elemental analyses, mass, 'H-,
"F-, P-NMR, IR,
and Raman spectroscopic studies. The
coupling scheme in the high-resolution 'H-NMR spectrum
is characteristic for the proton on the asymmetric C atom
(C*), and the two 3 1 P signals indicate two phosphorus
atoms in different chemical environments (Table 1). In the
IR spectrum the band for v(C-HaliphaJ absorbs at ca.
2925 cm-' (solid; KBr).
Table 1. Parameters of the 'H- and 31P-NMR spectra of compounds
(7a) to ( 7 c ) (TMS or H,PO, as standard).
N + OF + NO+ F
Received: May 5,1971 [Z 440 IE]
German version: Angew. Chem. 83, 586 (1971)
[l] I<. H . Homann, W C. Solomon, H . Gg. Wagner, J. Warnatz, and
C. Zetzsch, Ber. Bunsenges. Phys. Chem. 74, 585 (1970).
[2] H . E . Radford, V W Hughes, and V Beltram-Lopez, Phys. Rev. 123,
153 (1961).
[3] J S. M Harvey, Proc. Roy. SOC.(London) A 285, 581 (1965).
[4] A. Arkell, J. Phys. Chem. 73, 3877 (1969).
[ S ] E. H . Sraricco, J . E . Sicre, and H . J . Schumacher, 2. P h y s . Chem.
N F 31, 385 (1962).
[6] M . A. A . Clyne and J . A . Coxon, Proc. Roy. SOC.(London) A 303,
207 (1968).
[7] M . A. A . Ciyne and H . W Cruse, Trans. Faraday Soc.66,2214 (1970).
[S] M . A. A . Clyne and H.W Cruse, Trans. Faraday SOC.66,2227 (1970).
New Type of Reaction Resulting from the Action
of 0, on Diarylperfluoroacylpho~phanes~**~
By Ekkehard Lindner and Hans-Dieter Ebert"'
We recently reported the unusual result of oxidizing diphenyl(trifluoroacetyl)phosphane['*21,which reacts with
molecular oxygen to afford racemic I-(diphenylphosphoryl)-2,2,2-trifluoroethyl diphenylphosphinate. Further work
has shown that the formation of the ester is due to a new
type of reaction that occurs generally when a perfluoroacyl
and two aryl groups are bonded in the phosphane used
Ccf. ( I ) ] .
Compound
Nucleus
Coup'ing
constant [Hz]
(70)
in ID,]-Acetone
'H
2JHp=12.5
'JKP=
4.7
3.fKF=
7.8
(7a)
3'P
'
(ppm)
Measured
at [MHz]
- 6.128
90
-23.170
30
- 36.670
in [D,]-Nitromethane
(7bJ
in [D,]-Nitromethane with
[DeI-DMSO
'H
(7bl
in CH3CN
3IP
(7c)
in [D,]-Nitromethane with
[D,]-DMSO
'H
'J,,
= 12
- 6.2
60
-22.7
36.43
6
3~,,=12
3J,p=
- 35.2
25,,=12
-
6.23
3~,,=12
The corresponding alkali diarylphosphinates and fluorinated alcohols are formed on alkaline hydrolysis of ( 7 a )
to ( 7 e ) :
(OPR2),0CHR,+2 H O -
-
2 R,P(O)O-+R,CH,OH
On the basis of these results we suggest the follow course
for the formation of compounds ( 7 j t 4 ] :In the first step,
0, adds to ( I j ; a transition state i s assumed to consist of
..Pr
...
RY
13)
( 7 a ) , R = C 6 H , , R,=CF,
( 7 6 ) , R = C,H,, R, = C,F,
(7c), R=C,H,,R,=C,F,
(7d),R=C6D,,R,=CF3 [3]
( 7 e ) , R=p-CH,C,H,, R,=CF,
A prerequisite for this course of the reaction is the presence
of a small amount of H,O, which affords the H atom on the
center of chirality; on the other hand, the solvent is only of
subordinate importance since the same products are
formed in similar yields (ca. 25%) in benzene, toluene,
cyclohexane, hexane, and even C,D, or dodecafluoro[*] Priv.-Doz. Dr. E. Lindner and Dipl.-Chem. H.-D. Ebert
Institut fur Anorganische Chemie der Universitat
852 Erlangen, Fahrstrasse 17 (Germany)
Y'I This work was supported financially by the Deursche Forschungsgemeinschaft and the Fonds der Chemischen Industrie.
Angew. Chem. internat. Edit. 1 Vol. 10 (1971) 1 No. 8
60
'JH,= 45
(3) + HOH
+
-
0
COz + O = P R Z
(4)
RrH + OH'
(2), which decomposes into (3), ( 4 ) , and CO,; a similar
mechanism has been formulated for the oxidation of alkylidenepho~phoranes~~].
The ions (3) and ( 4 ) do not
combine. We assume rather that ( 4 ) attacks a second molecule of the starting material ( I ) , while the R; ion (3)
reacts with H,O to yield R,H and HO-. The HO-. then
clearly adds to the cation (Sb), forming (6). In a final step,
(6) stabilizes itself to the ester (7). The stable by-products
CO, and 1H-perfluoroalkane (R,H) were unambiguously
identified in all cases.
Received: May 7,1971 [Z 441 It]
German version: Angew. Chem. 83,587 (1971)
[i] E . Lindner,H.-D. Ebert, and P. Junkes, Chem. Ber. 103,1364 (1970).
[2] E. Lindner, Angew. Chem. 82,143 (1970); Angew. Chem. internat.
Edit. 9, 114 (1970).
[3] E. Lindner,H.-D. Ebert, and A . Haag, Chem. Ber. 103,1872 (1970).
[4] We thank Prof. H . J . Bestmann for numerous discussions.
[S] H . J . Bestmann, H . Haberlein, and 0. Kratzer, Angew. Chem. 76,
226 (1964); Angew. Chem. internat. Edit. 3, 226 (1964); H . J . Bestmann
and 0. Kratzer, Chem. Ber. 96, 1899 (1963).
Experimental
2,6-Di-tert-butylbenzoquinone
4-dimethylmethider21(1 g,
0.00406 mol), anhydrous neutral aluminum oxide (1to 2 g),
and light petroleum (15 ml ; b. p. 50-70°C) are heated
and stirred magnetically under nitrogen (gas stream) in a
round-bottomed flask, fitted with a reflux condenser, in an
oil-bath (70-80°C). The deep yellow color disappears at
once. The reaction is complete in 5-1 5 min. After cooling,
the mixture is placed together with the aluminum oxide
on a silica gel column and eluted with anhydrous light
petroleum (50 ml). Removal of the solvent affords 2,6-ditert-butyl-4-isopropenylphenol(0.95-1.0 g, 95-100%),
m. p. 77-78°C.
Received: May 13, 1971 [Z 442 IE]
German version: Angew. Chem. 83,617 (1971)
[I] D.Braun, R . J . Faust, and B. Meier,Angew. Chem. 80,407 (1968);
Angew. Chem. internat. Edit. 7, 393 (1968).
[ 2 ] C . D.Cook and B. E. Norcross, J. Amer. Chem. SOC.78,3797 (1956).
Nucleophilic Aromatic Substitution:
A New Synthetic Route to Biphenyls'']
By Franz Effenberger, Klaus Nagel, and Wolfgang Agster"'
Isomerization of Quinone Methides to
Alkenylphenols[**I
By Dietrich Braun and Bertold Meierr4'
During our studies of oxygen polyradicals['] we have
found a new synthesis of sterically hindered polymerizable
phenol derivatives by isomerization of the stable 2,6-ditert-butylbenzoquinone methides ( I ) to the corresponding
alkenylphenols (2).
The most important methods for preparation of biphenyls
are the Ullmann[21 and Gomberg reaction^'^], which
involve radical or organometallic intermediates ; furthermore, biaryls are formed by benzidine rearrangementL4]
and oxidative dirnerizationfs1,as well as in the course of
reactions involving aryne intermediates16].
OH
0
70-759:
Petroleum e t h e r
RNC'CH3
(1)
+
Y=CH2
R
(2)
= tert-Butyl; R = H , CH3, Phenyl
The isomerization occurs extremely rapidly and quantitatively on use of neutral aluminum oxide. Use of acid
aluminum oxide is possible but leads to yields of only
50-60% because part of the isomeric compounds are
bound to the catalyst as carbonium ions or react further
by oligomerization. Basic aluminum oxide is not suitable
because sterically hindered phenols are oxidized in a basic
medium by atmospheric oxygen, yielding oily products
when the reaction mixture is worked up. It is also impossible
to isolate the alkenylphenols if the aluminum oxide is
replaced by traces of protic or Lewis acids. This method
of isomerization is superior to the classical processes
(dehydration of carbinols or decarboxylation of substituted
cinnamic acids)['] because the alkenylphenols are immediately provided in a very pure state.
R'
R2
R3
Pyr
Pyr
Pyr
Pyr
Pyr
Pyr
Pyr
CH,
H
H
H
H
H
NO2
NO2
CN
COOCH,
COOH
H
H
H
H
H
R4
H
H
NO2
COOCH,
[*I
Prof. Dr. D. Braun and Dip1.-Ing. B. Meier
Deutsches KunststoR-Institut
61 Darmstadt, Schlossgartenstrasse 6 R (Germany)
[**IThis work was supported by the Deutsche Forschungsgemeinschaft.
566
[*I
Prof. Dr. F. Effenberger, Dip].-Chem. K. Nagel, and W. Agster
Institut f i r Organische Chemie der Universitat
7 Stuttgart, Azenbergstr. 14-18 (Germany)
Angew. Chem. internat. Edit. Vol. 10 (1971) 1 NO.8
Документ
Категория
Без категории
Просмотров
4
Размер файла
189 Кб
Теги
reaction, diarylperfluoroacylphosphanes, action, typed, resulting, new
1/--страниц
Пожаловаться на содержимое документа