close

Вход

Забыли?

вход по аккаунту

?

Dicarbonyl Derivatives of 1 6-Bridged [10]Annulenes.

код для вставкиСкачать
Table 1. NMR spectra of compounds ( 5 ) to (8) [a]. Chemical shifts 6'H, 6')C, and 6j'P are in ppm with reference, respectively, to TMS (internal),
benzene (external), or H,PO, (external). Values at lower field are given as negative. 6l3C was measured with (CD,),C*O as external standard and
calculated by subtraction of 77.0 ppm. CouplingconstantsJ are in Hz. Values in parentheses are signal multiplicities, m indicating an unresolved multiplet.
~
R
6,'P
(5)
(5)
C,H,
n-C,H,
( 6 ) CH,
(7) C,H,
(8) CH,
undiluted
inCH,CI,
6°C
-CH=
JPNc 6'H
- 27.9
- 7.93 (2)
-26.7
-40.8 (2) 10.0
-27.7
-42.4 (3)
undiluted
inCH,CI,
- 17.1
inCH,CI, o [b]
p
-25.8
-18.3
5.5
-7.95 (2)
R,N-
JPNCH 6',C
6'H,
39.5
39.6
- 3 . 0 7 ( 2 ~ 4 ) 11.9 -1.10(3) 7.1
-2.95 (m)
ca. 11 - 1.95 to
-0.47 (m)
+ 84.5
+ 98.2
+ 109.1
+ 95.7
-7.82 (2)
47.4
36.6
22.0
- 8.25 (2 x 2)
49.2
- 8.63 (2)
somewhat lower field['] than, those of the symmetric compounds ( 4 ) , 613C= - 3 9 . 0 ~10-6[81 and ( 9 ) , R=CH,,
On the other hand, the chemical
h3'P= -25 x
shifts of the ring methine protons of ( 5 ) and (6) have
moved to higher field by 1.3 and 1.4 ppm, respectively, in
comparison with that of ( 4 ) 6'H= -9.25 x 10-6['01. This
can be interpreted as a considerable weakening of the
magnetic anisotropy of the triazine ring caused by inclusion
of P(NR2), as a ring member in place of CH ; inclusion of
a second P(NR,), ring member makes, however, little
difference to this. In comparison, benzene protons are
shifted by ca. -1.6 ppm by the anisotropy of the ring. A
large endocyclic PNCH coupling'"' is characteristic for
all the compounds described here; the value for (8) is the
largest ,JPHvalue ever reported.
JPNCH
-2.57 (2)
-3.18(2~4)
-2.86(2)
-2.73 (3)
11.2
12.8
11.4
11.2
G'H6-s
-1.17(3)
JH~cH
7.1
H,C-N<
6'H
JPNCH
-3.90(1)
-3.37 (2) 7.2
Dicarbonyl Derivatives of 1,bBridged [lO]Annulenes
By Emanuel Vogel, Elmar Lohmar, Walter A. Bull, Bernd
Sohngen, Klaus Miillen, and Harald Giinther[*]
For a systematic comparison of bridged [IO]annulene~['~
with the classical aromatic compounds benzene and
naphthalene it would be of considerable interest to clarify
the problem of whether dicarbonyl derivatives of 1,6methano[ 10lannulene ( 4 ) are to be regarded as "quinones".
It can easily be seen that the same number and same types
of "quinones" can be derived from ( 4 ) as from naphthalene. Bicyclo[4.4.l]undeca-3,6,8,lO-tetraene-2,5-dione( I ) ,
bicyclo[4.4.l]undeca-3,5,8,lO-tetraene-2,7-dione( 2 ) and
bicyclo[4.4.l)undeca-1,4,6,9-tetraene-3,8-dione ( 3 ) may
be named as representative members. We here report
attempted synthesis of the compound ( I ) .
2,2-Bis(dialkylamino)-Z,3,5,2-triazaphosphorines
and 2,2,4,4tetrakis (dialkylnmino) -IJ,5,2,4-triazadiphosphorines
A benzene solution of an aminophosphazene (2) or aminodiphosphazene ( 3 ) is treated with two-thirds or one-third,
respectively, of the equimolar amount of s-triazine. When
the mixture is heated to the boiling point ammonia is
evolved and the triazine dissolves. After 3 4 h the benzene
is distilled off and the residue is then distilled at 1 torr and
a bath-temperature of 120°C (R=CH3 or C,H,) or is
chromatographed (R=n-C,H,) in CH,C12 on A1,0,. The
products are colorless liquids and analytically pure and
are obtained in yields of 70-90%.
Received: March 4,1971 [Z 386 IE]
German version: Angew. Chem. 83, 398 (1971)
[I] Part 41 of Phosphazenes.-Part 40: A . Schmidpeter and W Zeiss,
Angew. Chem. 83, 397 (1971); Angew. Chem. internat. Edit. 10, 396
(1971).
[2] A . Schmidpeter, C . Weingand, and E. Hnfner-Roll, Z. Naturforsch.
24b, 799 (1969).
[3] Recently it was found for another compound with a PNCNC chain
that only the CNC nitrogen was methylated: I . N . Zhmuroua, A. P.
Martynyuk, and A . V Kirsanou, J. Gen. Chem. USSR 39, 1193 (1969).
[4] J . Ebeling, N . Schindler, and A . Schmidpeter, Chem. Ber., in press.
[5] E. M . Smolin and L. Rapport in A . Weissberger: The Chemistry of
Heterocyclic Compounds. Interscience, New York 1959, Vol. 13.
[6] D. Feakins, W! A . Last, and R. A. Shaw, Chem. and Ind. 1962,510.
[7] Cf. A . Schmidpeter and K. Schumann, Z. Naturforsch. 25b, 1364
(1970).
[8] P . C . Lauterbur, J. Chem. Phys. 43, 360 (1965).
191 M . Becke-Goehring, K. John, and E. Fluck, Z. Anorg. Allg. Chem.
302, 103 (1959).
[lo] I. Nicholson, Chem. Commun. 1968, 1028.
[ l l ] A . Schmidpeter and J . Ebeling, Angew. Chem. 79, 534 (1967);
Angew. Chem. internat. Edit. 6, 565 (1967).
398
On treatment with lead tetraacetate in glacial acetic acid
at 6O-8O0C, 1,6-methano[lO]annulene ( 4 ) affords the cis1,4-diacetate (51, m.p. 145-147"C, in 30% yield with high
stereoselectivity. The presence of the norcaradiene structural moiety in ( 5 ) and the cis-configuration of the acetate
groups follow compellingly from the 'H-NMR spectrum
[(in [D,]benzene) AA'BB' system, centered at 7 = 3.9
(4H); singlets at 4.38 (2H), 4.61 (ZH), and 8.27 (6H); AB
system at 7.48 and 9.82 with J=6.2Hz (2H); J(13C-H)
&
PI
Pb(OAc),,
&' &
Prof. Dr. E. Vogel, Dr. E. Lohmar, Dr. W.A. Boll, DipLChem.
B. Sohngen, Dip1.-Chem. K. Miillen, and Prof. Dr. H. Giinther
Institut fur Organische Chemie der Universitat
5 Koln 1, Ziilpicher Strasse 47 (Germany)
Angew. Chem. internat. Edit. 1 Vol. 10 (1971)
No. 6
of the proton at highest field: 159 Hz]. The configuration
of the acetate groups in relation to the cyclopropane ring
still remains to be clarified. When the diacetate was
treated with ethereal methyllithium at -50°C, a diol of
m.p. 151-152°C (yield 74%) was formed which, according
to the NMR spectrum has structure ( 6 ) . The diol ( 6 )
can be converted by manganese dioxide in benzene almost
quantitatively into a yellow dicarbonyl compound, m. p.
107-108"C, which is stable in absence of light and oxygen
and to which the norcaradiene structure (7) must be
assigned unambiguously on the basis of spectral findings.
19F-NMRspectrum [(CDCl,); CC1,F as external standard]
contained an AB system at 103.5 and 110.8ppm with
3=238 Hz. The presence of a cycloheptatriene is convincingly shown by the coupling constants of the olefinic
protons H'-H''
(see Table 1) and by the absorption of
these protons at relatively low field strengthc7].Furthermore, the I9F-NMR parameters point to this type of
structure, for if the CF, group were part of a cyclopropane
ring the fluorine atoms should not only absorb at higher
field strengths but also should show smaller geminal
coupling['- 'I.
The NMR spectrum of the dicarbonyl compound (in
[D,]acetone) shows an AA'BB' system (H7-H") centered
at '5 = 3.52, a singlet at 3.49 (H3, H4), and an AB system at
7.41 (anti-H")[31 and 9.22 (syn-H") with 3=4.1 Hz. The
coupling constants of the olefinic protons H7-H10[41
(see Table I), on the one hand, and the geminal coupling
of the CH, protons on the other provide a decisive argument in favor of structure (7). The electron spectrum [(in
methanol), h,,,=226
( E = 15400), 271 (2240), 324 (248),
405nm (186)] also supports the structure (7); the IR
spectrum, with a broad carbonyl band at 1665cm-' (in
KBr) is not very revealing.
The electron spectrum of the compound [(in methanol)
h,,,=210 (~=27900),236 (15350), 245 (15100, sh), 318
(2600), 398 (325), 415 nm (300)] indicates, in accord with
structure (Y), stronger conjugation than in the norcaradiene (7). The IR carbonyl absorption [relatively sharp
band at 1658 cm-' (in KBr)] corresponds, as does that
of (7), to that of an ccJ3-unsaturated ketone or of a quinone["'.
Chemical and physicochemical studies of (7) and ( 9 )
are in progress to provide further information about the
quinonoid nature of these dicarbonyl compounds.
Table 1. Chemical shifts (5 values in ppm) and H,H coupling constants
(Hz)of the olefinic protons in (7) and ( 9 ) .
(7) 3.25 [a] 3.88 [a] 3.49
(9) 2.82
12.44
13.38
I ::;:
6.03 0.83
110.59 10.12
1 ::::
[a] The assignment of H', HIo, and of H8, H9, respectively, is uncertain.
The replacement of the two methylene protons in (7) by
fluorine offers the possibility of shifting the position of
the equilibrium between the norcaradiene and the cycloheptatriene tautomer in favor of the latter [(7)$(1)
versus (S)+(Y)], for, as the thermal behavior of perfluorocyclopropanes shows, ring strain is considerably
increased by geminal fluorine sub~tituents~'~.
11,ll-Di fl uoro - 1,6- methano [1O]ann~lene[~Ireacts with
lead tetraacetate in glacial acetic acid in the same way
as ( 4 ) , although less readily (reflux), yielding a symmetrical cis-1,4-diacetate (m.p. 171-172°C; yield 10%). The
'H-NMR spectrum of the compound confirms the expectation that in this case we are dealing with a cycloheptatriene derivative, and the same applies to the diol [m.p.
175-176 "C (several recrystallizations from ethyl acetate) ;
crude yield 78x1 obtained from the diacetate by means
of methyllithium at - 50°C. Finally, oxidation of the crude
diol with manganese dioxide in acetone afforded the
desired 11,11-difluorobicyclo[4.4.1]undeca-3,6,8,10-tetraene-2,5-dione (9) as a light-sensitive yellow compound of
m.p. 119-120°C (yield 50%).
Received: December 24,1970 [Z 385a IE]
Publication delayed at the authors' request
German version: Angew. Chem. 83,401 (1971)
[I] Reviews: a) E . Vogel in: Aromaticity, Special Publication No. 21,
Chem. SOC.,London 1967, p. 113; b) E . Vogel, Chimia 22, 21 (1968);
c) E. Vogel, Proc. Robert A. Welch Foundation Conferences on Chemical Research, XII. Organic Synthesis, Houston, Texas, 1968, p. 215.
[2] For synthesis of (2) see E . Vogel, W A . Boll, and E . Lohmar,
Angew. Chem. 83, 403 (1971); Angew. Chem. internat. Edit. 10, 399
(1971).
131 syn and anti refer to the diene part of the molecule.
[4] H. Giinther and H.-H. Hinrichs, Liebigs Ann. Chem. 706, 1 (1967).
[5] R. A. Mitsch and E. W Neuuar, J. Phys. Chem. 70, 546 (1966);
see also H. Giinther, Tetrahedron Lett. 1970, 5173.
161 V: Rautenstrauch, H.-J. Scholl, and E. Vogel, Angew. Chem. 80,
278 (1968); Angew. Chem. internat. Edit. 7, 288 (1968).
[7] The position of the AA'BB'system of the protons H7-HI0 reflects
strong conjugation between the two halves of the molecule, such as is
present only in the cycloheptatriene structure.
[8] References for 19F-NMR parameters of gem-difluorocyclopropanes: a) R. A . Mitsch, J. Amer. Chem. SOC.87, 758 (1965); b) W D.
Phillips, J. Chem. Phys. 25, 949 (1956).
[9] The spectral data for (7) and (9) do not exclude the possibility
that these compounds exist in rapidly established equilibrium with
their cycloheptatriene or norcaradiene tautomers [ ( I ) and (8)
respectively] ; the concentrations of tautomers ( 1 ) and (8), however,
should not exceed 20%. If more than ca. 5% of ( I ) and (8) were
present, the NMR spectra should be temperature-dependent (measurements are in progress).
[lo] We thank Dr. P. Junkes for determination of the I9F-NMR
spectra.
[ll]
With potassium tert-butoxide in dimethyl suifoxide, the tricyclic
dicarbonyl compound (7) affords a semiquinone which, according to
its ESR spectrum, has a bicyclic structure: G. A. Russell, ?: Ku, and
J. Lokensgard, J. Amer. Chem. SOC.92,3833 (1970).
Bicyclo[4.4.l]undeca-3,5,8,10-tetraene-2,7-dione
By Emanuel Vogel, Walter A . Boll, and Elmar LohmarI']
Structure (9) was proved by the NMR spectra. The 'HNMR spectrum ([ID,]-acetone) contained an AA'BB'
system (H7-H") disturbed by H, F coupling and centered
at ~=2.62,as well as a singlet at 3.38 (H3, H4), whereas the
Angew. Chem. internat. Edit. 1 Vol. 10 (1971) 1 No. 6
Bicyclo[4.4.l]undeca-3,6,8,lO-tetraene-2,5-dione(2), a diketo derivative of 1,6-methano[lO]annulene corresponding
to p-benzoquinone or 1,4-naphthoquinone, defies attempts
at synthesis because, contrary to expectation, it has a
[*] Prof. Dr. E. Vogel, Dr. W.A. Boll, and Dr. E. Lohmar
Institut fur Organische Chemie der Universitat
5 Koln 1, Ziilpicher Strasse 47 (Germany)
399
Документ
Категория
Без категории
Просмотров
1
Размер файла
245 Кб
Теги
annulenes, bridge, derivatives, dicarbonyl
1/--страниц
Пожаловаться на содержимое документа