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Cyclodisalazane CationsЧSynthesis and Crystal Structure.

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any absolute and relative configuration-for pharmacological investigations, but also for structural elucidations.
Received: May 20, 1986;
revised: August I, 1986 [Z 1782/1783 IE]
German version: Angew. Chem. 98 (1986) 917
[ I ] a) T. R. Govindachari, P. C. Parthasarathy, Tetrahedron 27 (1971) 1013;
b) T. R. Govindachari, K. Nagarajan, P. C. Parthasarathy, T. G. Rajagopalan, H. K. Desai, G. Kartha, S. Lai Chen, K. Nakanishi, J. Chem. Soc.
Perkin Trans. I 1974. 1413.
I 4 M. Shamma: The Isoquinoline Alkaloids. Academic Press, New York
1972, p. 501.
131 Reviews: a) T. R. Govindachari, P. C. Parthasarathy, Heterocycles 7
(1977) 661; b) G. Bringmann (The Naphthyl Isoquinoline Alkaloids) in
A. Brossi (Ed.): The Alkaloids. Vol. 29, Academic Press, New York, in
press, p. 14 1 : c) in: 3S Jakre Fonds der Ckemischen Industrie. 1950-1985,
Verband der Chemischen Industrie, Frankfurt 1985, p. 151.
[4] G. Bringmann, J. R. Jansen, Tetrahedron Lett. 25 (1984) 2537.
[ S ] For syntheses of arylpropanones, see a) S. Ahmad, W. B. Whalley, D. F.
Jones, J . Chem. Soc. C1971, 3590; b) H. B. H a s , A. G. Susie, R. L.
Heider, J. Org. Chem. I5 (1950) 8.
[6] G. Bringmann, J. R. Jansen, Heterocycles 24 (1986) 2407.
[7] G. Bringmann, Liebigs Ann Chem. 1985. 2126.
[8] a) F. Weinges, G. Graab, Chem. Ztg. 94 (1970) 728; b) D. E. Nichols, C.
F. Barfknecht, D. B. Rusterholz, J . Med. Chem. 16 (1973) 480; c) G.
Knupp, A. W. Frahm, Arch. Pharm. (Weinheim. Ger.1318 (1985) 535, and
references cited therein.
I91 Not only 1 but, in fact, all naphthyl isoquinoline alkaloids whose structures have been elucidated unequivocally exhibit the (S)configuration
at C-3 of the isoquinoline moiety. Cf. 131.
[lo] Enantiomeric purity determined by ‘H-NMR spectroscopy of 3 as the
amide of (S)-2-methoxy-2-trifluoromethylphenylacetic
acid 2 93%, for
an ee value of 94% for the phenylethylamine employed. For derivatization, see J. A. Dale, H. S. Mosher, J. Am. Chem. SOC.95 (1973) 512, and
references cited therein.
[ I I] K. Maruoka, H. Yamamoto, Angew. Chem. 97 (1985) 670; Angew. Chem.
Int. Ed. Engl. 24 (1985) 668, and references cited therein.
[I21 Similarly high diastereomeric excess had previously been achieved in
the reduction of tetrahydropyridines with LiAIH*/AIMe, (see [I I]).
These results had been discussed in terms of the attack of “HQ,”occurring, on the one hand, as homosynplanar as possible to the axial CH,
group on C-6 (dashed circle) and, on the other hand, as antiperiplanar
as possible to the axial H atom on C-3 (circle) of the tetrahydropyridine
ring, forced to adopt conformation A on account of the Al complexation. Since C-3 is no longer sp’ hybridized in the dihydroisoquinoline
system B, the latter effect is no longer present. As a result, such high
diastereomeric excesses could not be expected. On the other hand, the
results are stereochemically in agreement with the findings for iminium
salts (and thus cationic systems). Cf. P. Deslongchamps: Stereoelectronic
E’eects
in Organic Chemistry. Pergamon Press, Oxford 1983, Chap. 6.
I
A
H@
I
B
H@
[ 131 For selective ether cleavage in multiply methoxylated isoquinolines, see
A Brossi, S. Teitel, Helv. Chim. Acta 53 (1970) 1779; R. W. Gray, A. S.
Dreiding, ibid. 63 ( 1980) 3 15.
[I41 For similar coupling reactions involving appreciably simpler arenes, see
D. E. Ames, A. Opalko, Tetrahedron 40 (1984) 1919.
[IS] G. Bringmann, S. Schneider, Synthesis 1983. 139.
[I61 The likewise possible 7-1‘ coupling, which is not observed in this case,
would lead to the structural type of ancistrocladisine. Cf. [3].
1171 Authentic samples of 1 and 16 were isolated from Ancistrocladus hamatus. We thank Dr. G . Reisch and Prof. Dr. Dr. J . Reisch, Institut fur
Pharmazeutische Chemie der Universitat Munster, and Prof. Dr. A . A . L.
Gunatilaka. University of Peradeniya, Sri Lanka, for providing us with
samples of the plants.
[IS] T. R. Govindachari, P. C. Parthasarathy, T. G. Rajagopalan, H. K. Desai, K. S. Ramachandran, E. Lee, Indian 1. Chem. 13 (1975) 641.
Anyec, Chem Inr Ed. Engl. 25 11986) No. 10
Cyclodisalazane CationsSynthesis and Crystal Structure**
By Ursula Kliebisch, Uwe Klingebiel,* Dietmar Stalke,
and George M . Sheldrick
The nitrogen atom in silicon-nitrogen compounds is almost always in a structurally- planar
environment, and
.
rarely exhibits basic properties ;1i.21 adducts-which frequently undergo further reaction and consequently cannot
be isolated-are formed only with very strong Lewis acids.
Protonated silazanes have, to out knowledge, never been
detected so far.
Hitherto, there have been two major objectives on carrying out reactions of aluminum trihalides with silazanes:
First, the synthesis of aluminum ~ilazanes,[3-~]
and second,
the synthesis of compounds with threefold coordinated silicon.‘6-81The stabilization of silicon ylides by adduct formation with aluminum trihalides1’1 motivated us into investigating reactions of cyclosilazanes with AI,CI,.
was heated in n-hexanel
When the cyclosilazane lL9]
dichloromethane (10:3 v/v), a phase separation was observed upon cooling the mixture. Evaporation of the dichloromethane phase to dryness furnished the salts 2
and 3 as solids: monoprotonated 1 with AlCI? as counter-
iPr
\
iPr
/
/
si
\
ipr
tBu
iPr
2
iPr
/
\
iPr
iPr
iPr
1
iPr
/
\
iPr
3
ion,’”’ and diprotonated 1 with the novel dianion
QCl,AI-O-AICI~ as counterion.‘”’ Repeated crystallization from n-hexane/dichloromethane afforded crystals of
3 sufficiently suitable for an X-ray structure analysis. Apparently the formation of 3 involves participation of traces
of water during the reaction and/or during the work-up o f
the reaction mixture.[l21
1 does not react with Al,C16 in the absence of dichloromethane, and can be recovered without decomposition ;
consequently, CH,CI, functions as a reactant. Degradation
products of dichloromethane were not detected. The stability of salts such as 2 and 3 can be ascribed to kinetic
stabilization by the large substituents.
It follows from the 29Si-NMR spectra of 1 (6= 7.44),19]2
(6=30.05) and 3 (6=30.84) that the Si atoms in 2 and 3
are strongly deshielded. The ’IN-NMR resonances of 2
and 3 appear in the region characteristic for quaternary
~’
ammonium salts. The Si-N bonds in 1 (174.7 ~ m ) [ are
[*I Prof. Dr. U. Klingebiel, U. Kliebisch, D. Stalke, Prof. G. M . Sheldrick
lnstitut fur Anorganische Chemie der Universitat
Tammannstrasse 4, D-3400 Gottingen (FRG)
I**] This work was supported by the Deutsche Forschungsgemeinschaft and
the Fonds der Chemischen Industrie.
0 VCH Verlagsgesellscha/t mbH. 0-6940 Weinherm, 1986
0570-0833/86/1010-091S $ 02 S0/0
9 15
significantly shorter than in 3 (179.2 pm), i.e. they are weakened due to the sp3-hybridization of the nitrogen. The existence of the NH-protons was confirmed by "N-and 'HN M R spectroscopy. Each of the N-C bonds subtend an
angle of 16.8" to the
plane. This unusual configuration at the nitrogen is indicative of protonation.
\ C(311
[Sl M. Veith, H. Lange, A. Belo, 0. Recktenwald, Chem. Ber. 118 (1985)
1600.
[61 A. H. Cowley, M. C. Cushner, P. E. Riley, J. Am. Chem. Soc. 102 (1980)
624.
[71 W. Clegg, M. Haase, U. Klingebiel, J. Neernann, G. M. Sheldrick, J .
Organomel. Chem. 251 (1983) 28 1
[81 W. Clegg, U. Klingebiel, J. Neernann, G. M. Sheldrick, J . Orgunomel.
Chem. 249 (1983) 47.
191 W. Clegg, M. Haase, G. M. Sheldrick, N. Vater, Acra Crystallogr. C40
(1984) 87 I ; N. Vater, Dissertation, Universitat Gottingen 1984.
I101 2 : M.p. 120°C (decomp.); molecular mass osmometrically in
CHCI,=553/2; 'H-NMR (CDCls, TMS int.): 6= 1.8-1.2 (rn. CHMe2),
1.36 (NCMe3), 1.53 (NHCMe,), 3.58 (NH); "C-NMR (CDCI,, TMS
int.): 6= 16.34 (SIC), 17.97, 18.18, 18.23, 18.81 (SiCC,), 31.39 (NCC,),
34.1 1 (NHCC,), 51.50 (NC), 59.27 (NHC); 'IN-NMR (CDCI,, M e N 0 2
ext.):6= -311.7(NCMe3), -309.9(NHCMe3, J,,=60 Hz); '"Si-NMR
(CDCI,, TMS int.): 6=30.05.
[ I l l 3 : W N M R (CDCI,, TMS int.): 6=33.46 (NCC,), 60.6 ( N O ; "NNMR (CDCI,, M e N 0 2 ext.): 6= -296.8 ( J N H = 6 5 Hz); "Si-NMR
(CDCI5, TMS int.): 6=30.8.
1121 D. Jentsch, P. G. Jones, E. Schwarzmann, G. M. Sheldrick, Acta Crystullogr. C 3 9 (1983) 1173; U. Thewalt, F. Stollrneier, Angew. Chem. 94
(1982) 137; Angew. Chem. Int. Ed. Engl. 21 (1982) 133; Angew. Chem.
Suppl. 1982, 209.
A Salt of the Dication
Cycloheptatrienylidenemethyleneditropylium
By Kiyoham Mizumoto, Hideki Kawai. Keiji Okada, and
Masaji Oda *
d
Fig. 1. Crystal structure of 3. Stoe-Siemens AED diffractometer with graphite-monochromatized MoKn radiation @=71.069 pm) at room temperature:
size of crystal 0.46x0.46 xO.77 mm'; 4652 reflections with 7 " < 2 8 < 5 0 " ,
1640 symmetry-independent with F > 4 o ( R . The structure was solved by direct methods. All atoms other than H were anisotropically refined. Geometrical placement of the nine H-atoms of the terr-butyl groups (C-H length:
96 pm, H-C-H bond angle 109.9", U(H)-1.5 U,,(C), Ue,(C)= 1/3 (trace of
the orthogonal U,, tensor)). The same holds true for the H atoms of the secondary-C-atoms of the isopropyl groups, but with U(H)= 1.2 U,,(C). The H
atoms on the nitrogen could not be unambiguously located, even by a highangle refinement with subsequent difference Fourier synthesis. I n the diagram they have been positioned according to their ideal geometry.-Space
group C2/c, 2 = 4 , a = 1482.5(2), b = 1247.9(4), c = 1866.7(3) pm,p=98.63(2)',
@(MoKa)= 0.64 mm -', R = 0.055, R , = 0.054 ( w - = ( ~ ' (+0
0.0002 9).
Further details of the crystal structure investigation are available on request
from the Fachinformationszentrum Energie, Physik, Mathematik GmbH, D7514 Eggenstein-Leopoldshafen2 (FRG), on quoting the depository number
CSD-52 105, the names of the authors, and the full citation of the journal.
A number of ionic compounds having the bicyclic crossconjugated structure 1 (m, n 2 1 ) have been synthesized as
stable substances;['-41however, none of the tricyclic analogues 2 are known. These molecules would be of interest
from both structural and physicochemical points of view.
We wish to report the synthesis of cycloheptatrienylidenemethyleneditropylium 4 , a novel dication of type 2
(1 = m = n = 3), which was isolated as the bis(tetrafluoroborate) salt, 4 . 2 B E .
r
2 0
lv
Or
( C H=CH),
2 0
'
Experimental
A thick suspension of freshly sublimed AI2CI0 (8 g, 0.03 mol) in n-hexane
(100 mL) and CH2C12(30 mL) was treated with 11.1 g (0.03 mmol) of 1 and
the mixture heated for 2 h. Upon cooling, the mixture separated into two
phases; the lower phase contained the aluminum salt. This phase was separated, covered with 10 m L of n-hexane, and cooled to - 150°C. 3 crystallized
out, while 2 was isolated as an amorphous powder after removal of the solvent. Yields: 7.3 g (45%) of 2 and 1 g (5%) of 3.
Received: May 26, 1986;
revised: July 1 I , 1986 [Z 1790 IE]
German version: Angew. Chem. 98 (1986) 921
~
[I! E. A. V. Ebsworth in A. G. McDiarmid (Ed.): The Bond to Carbon, M.
Dekker, New York 1968, p. I .
[2] H. Burger, Angew. Chem. 85 (1973) 519; Angew. Chem. Inr. Ed. Engl. 12
(1973) 474.
[3] H. Schmidbaur, M. Schmidt, Angew. Chem. 74 (1962) 327; Angew.
Chem. I n f . Ed. Engl. I (1962) 327.
[4] U. Wannagat, T. Blumenthal, D. J. Brauer, H. Burger, J . Organomet.
Chem. 249 (1983) 33.
9 16
0 VCH VerlagsgeseIl.~chajimhH, 0-6940 Weinheim, 1986
J
1
cation 3, m
2
=
n
=
3
dication 4, 1
=
m
=
n
=
3
Thermal sigmatropic [ l , 51 hydrogen shift of the ketone
S1'I (140"C, xylene, 6 h) gave di( 1,3,6-cycloheptatrienyl)
ketone 5 and 1,3,6-cycloheptatrienyl 2,4,6-cycloheptatrienyl ketone in 47 and 33% yield, respectively (Table 1).[61 As
the key step for the construction of the carbon skeleton of
4, the ketone 5 was transformed into the heptafulvalene 6
employing Kilahara-Asao's heptafulvalene synthesis with
7-carbonyl~ycloheptatriene.~'~
Thus, dropwise addition of
7-cycloheptatrienecarbonylchloride(1.7 equiv.) into a refluxing benzene solution of 5 and triethylamine (2.0
equiv.) under nitrogen atmosphere provided 6 in 5-10%
yield as a red, acid- and air-sensitive oil, in addition to the
lactone 7 (50-70% yield). Treatment of 6 with triphenylmethyl tetrafluoroborate (2.2 equiv.) in dry acetonitrile
(room temperature, 1 d) gave the dication 4 as the salt
['I
Prof. Dr. M. Oda, Dip1:Chern. K. Mizumoto, DipLChem. H. Kawai,
Dr. K. Okada
Department of Chemistry, Faculty of Science, Osaka University
Toyonaka, Osaka 560 (Japan)
0570-0833/86/1010-09/6 $ 02.50/0
Angew. Chem. Inr. Ed. Engl. 25 (1986) No. 10
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