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Facile Synthesis of Highly Reactive Ferracycloalkanes.

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The four-membered heterocycles 3 with trans-oriented
CF3 groups are the major products of the 12 21-cycloaddition, whereas only small amounts of the cis-compounds 4
and head-to-head isomers 5 are formed; the product patterns for phosphorus and arsenic compounds under the
same reaction conditions are different.
3a : 4a : 5a : 6 a = 8 5 : 9 : 2 : 4
3b : 4b : 5b : 6 b = 6 4 : 21 : 3 : 12
This could be due to the greater activity of 2b, which also
facilitates reactions between monomers less favorably
oriented with respect to each other. In solution, the cisisomers 4a and 4b are transformed only very slowly into
the more stable trans-isomers 3a and 3b, respectively.
The "F-NMR spectrum of 3b is especially simple; it
shows two signal groups in the intensity ratio 3 :2 for the
two CF3 moieties (quintet) and the CF2 ring members (septet), thus indicating a planar ring structure (see Table 1).
Facile Synthesis of Highly Reactive
By Ekkehard Lindner*, Eckard Schauss, Wolfgang Hiller,
and Riad Fawzi
Dedicated to Professor Walter Riidorjf on the occasion
of his 75th birthday
Metallacyclopentanes occur as reactive intermediates in
numerous metal-catalyzed cycloadditions and cycloreversions of alkenes. For model studies of such systems, several five-membered metallacycles of some transition metals have been prepared or implicated as intermediates"].
Although Stone et a1.lZ1and Wilkinson et al.I3l described
perfluorinated ferracyclopentane, (OC),FeC,F,, as early as
1961, only now have we succeeded, for the first time, in
synthesizing the parent compound, tetracarbonylferracyclopentane 2a. The stereochemistry of the ring closure
reaction of ( T ~ - C ~ H ~ ) ~ F ~ to
( C2a
O )has
~ [ ~been
' analyzed
Table 1. 19F-NMRdata of 2a and Zb-6b [a]. For F' and F", see Figure 1.
(ddd) CF,, 2.9 (ddq) F', -29.1 (ddq) F; 'J(PF)=57.4,
2J(PF')= 192.0,
*J(PF")= 103.0,
4J(FF')= 10.0,
4J(FF')= 18.0
2b: 6= -41.2 (dd) CF3, 6.0 (dq) F', -11.4 (dq) F"; *J(F'F'')=60.0,
'J(FF')= 8.5, 4J(FF") = 17.0
3b: 6 = -44.3 (quint) CF,, -90.4 (sept) CF,; 4J(FF)=7.5
4b: 6 = -43.3 (tt) CF3, CF,: AB system, 6,= -77.8, &= -96.2;
'J(F(AB))=260, "J(FF)= 10.5, 4.5
5b: 6= -39.6 (quint, br.) CF,, -92.9 (br.) CF,; 4J(FF)=7.0
6b: 6 = -42.1 (quint), -41.1 (m,br.) CF,; -72.4 (m,br.), -74.1 (m,br.),
-80.7 (m, br.) CF,; 'J(FF)=7.0
Za: S=-44.4
[a] The data for 3a-6a agree with those quoted in the literature [2,6]. I9FNMR data (84.66 MHz) 2a: [Ds]toluene, -60°C; 2b: [D,]dimethyl ether,
- 110°C; 3b-6b: [D,]toluene, 28°C; external standard: CCI,F: J [Hz]. Data
for 2a in [I] not complete.
The elimination of Me3SnF could also be exploited for
the preparation of other heteroalkenes. Thus, the novel
compound Me3SnP=CF2 is formed on thermolysis of
(Me3Sn)?PCF3, and the known, unstable thia- and selenaalkenes E'=CF2 (E'=S, Se)"] can be obtained quantitatively from Me3SnE'CF3.
theoretically by Hoffmann et al'']. The nucleophilic elimination-cycloaddition of tetramethylenebis(trifluoromethanesulfonate)l6] with [Fe(CO),]'' now facilitates a straightforward route to the extremely volatile ferracyclopentane
2a, which precipitates at -78°C from n-butane as colorless crystals that are heat- and air-sensitive and readily soluble in all organic solvents.
X-ray structure analysis['] indicates that the more stable
2b['I, which is obtained analogously, has a twist conformation (Fig. l). Because of conformational chirality, C6 and
C7 are di~ordered''~.This was taken into consideration in
calculating the structure by introducing split positions ob-
Received: April 27, 1984;
revised: June 29, 1984 [Z 815 IEI
German version: Angew. Chem. 96 (1984) 716
[l] H. Eshtiagh-Hosseni, H. Kroto, J. F. Nixon, 0. Ohashi, J . Orgunumet.
Chem. 181 (1979) C1.
[2] A. B. Burg, Inurg. Chem. 20 (1981) 3734; 22 (1983) 2573.
[3] S . Ansari, J. Grobe, P. Schmid, J. Huurine Chem. 2 (1972/73) 281; S. Ansari, J. Grobe, 2. Nuturforsch. 8 3 0 (1975) 531; P. Dehnert, J. Grobe, D.
Le Van, ibid. 8 3 6 (1981) 48.
(41 Procedure: l a (3.33 g, 10 mmol) or l b (1.9 g, 5 mmol) is passed by suction (0.001 torr) through a pyrolysis tube 250 m m in length and 18 mm diameter ( l a at 300"C, l b at 340°C). l a or Ib are condensed in a cold trap
at -78"C, Za or 2b at - 196°C. The less volatile (Me,SnF), separates
out immediately after the hot zone. Unreacted l a or Ib is re-pyrolyzed
(complete reaction after ca. five cycles). Za and Zb are each formed quantitatively; the isolable yields are 1.38 g (92%) Za and (in [D6]dimethyl
ether at - 110°C) ca. 10% 2b together with ca. 90% 3b-6b.
[5] G. Becker, G. Gutekunst, Angew. Chem. 89 (1977) 477; Angew. Chem. Inr.
Ed. Engl. 16 (1977) 463; P. Jutzi, ibid. 87 (1975) 269 and 14 (1975) 232.
[6] D. K. Kang, A. B. Burg, J. Chem. Soc. Chem. Cumniun. 1972, 763; L.
Maya, A. B. Burg, Inurg. Chem. 14 (1975) 698.
171 K. Wittel, A. Haas, H . Bock, Chem. Ber. 105 (1972) 3865; A. Haas, B.
Koch, N. Welcman, Z . Anorg. Aflg. Chem. 427 (1976) 114; H. Bock, S.
Aygen, P. Rosmus, B. Solouki, E. Weissflog, Chem. Ber. 117(1984) 187.
Angew. Chem. Int. Ed, Engl. 23 (1984) Nu. 9
Fig. 1. Molecular structure of the enantiomers in the crystal of Zb in their staFe-CS 214.1(4),
tistical distribution. Selected distances [pm) and angles I"]:
Fe-C8 210.7(4), C5-C6 153.9(11), C5-C6' 154(2), C6-C7 151(2), C6'-C7'
153(3), C7-C8 149.5(10), C7'-C8 157(2), Cl-Fe-C4 162.0(2),C5-Fe-C8 82.5(2),
C5-C6-C7 108(1), CS-C6'-C7' 105(2), C6-C7-C8 109(1), C6'-C7'-C8 lOS(2).
[*] Prof. Dr, E. Lindner, E. Schauss, Dr. W. Hiller, R. Fawzi
lnstitut fur Anorganische Chemie der Universitat
Auf der Morgenstelle 18, D-7400 Tiibingen (FRG)
[**I Preparation and Properties of, and Reactions with, Metal-Containing
Heterocycles, Part 43. This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemiscben 1ndustrie.-Part
42: E. Lindner, C.-P. Krieg, W. Hiller, R. Fawzi, Chem. Ber., in press.
0 Verlug Chemie GmbH, 0-6940 Weinheim, 1984
0570-0833/H4/0909-0711 $ 02.50/0
tained by a difference Fourier synthesis. The C6C7 and
C6'C7' distances correspond to the length of a single bond.
2a, b were further characterized by elemental analysis as
well as by mass, IR, and '3C('H}-NMR spectra (Table I).
In 2a, the C atoms in the a- and p-positions, respectively,
are magnetically equivalent. In contrast, because of the
PPh3 ligand, in 2b four signals occur which are split into
doublets for C5, C7, and C8. The larger coupling constant
is ascribed to the trans-C8-Fe-P group. The assignment of
the signals is corroborated by studies of 2a, b in which the
P-positions of the ferracyclopentanes were labeled by deuterium (Table 1).
Table 1. Spectroscopic data and melting points for 2a, 2b, and 3b.
IR [cm-'1
W O ) [a1
''C('HJ-NMR 6
MS (m/z)
M.p. ["C]
2096 m-s
2032 s
2021 vs
2010 s-vs
22.1 (s, (253)
36.6 (s, C6,7)
2042 w
2024 vs
1977 vs
1965 s
1972 sh
1935 s-vs
21.0 (d, C8) [c]
26.8 (d, C5) [d]
35.0 (d, C7) [el
37.3 (s, C6)
212.1 (d,C2)[fl
205.1 (s, C2,3)
218.0 (d, C1,4) [g] 216.6(s,Cl)
212.2 (s, C1,4)
224 ( M " )
458 ( M e ) [h]
430 ( M " )
-35 (decomp.)
120 (decomp.)
[a] In n-hexane. [b] In CDCI,, 20.115 MHz, &value rel. TMS. [c]
zJ(CP)=10.2 Hz. [d] 'J(CP)=5.1 Hz. [el 'J(CP)=8.9 Hz. [fl *J(CP)=lO.O
Hz. [gl 'J(CP)= 14.0 Hz. [h] FD-MS (8 kV).
In the presence of CO, 2a is remarkably stable, and the
expected formation of cyclopentanone is observed only at
20°C['01.In the absence of CO, 2a decomposes already at
- 35 "C to afford Fe,(CO),, as well as cis- and trans-butene
in the molar ratio 1 : 2 .
The ethene complexes 3a["] and 3bf5]can be obtained
analogously and have been characterized by mass, IR, and
'3C{1H]-NMRspectroscopy (Table 1). 3a['I1has previously
been prepared from Fe2(C0)9 and C2H4, a method associated with tedious, laborious separation from Fe(C0)5. Xray structure analysis of 3bc7lconfirms the predicted equatorial arrangement['*] of ethene (Fig. 2).
[l] R. J. Puddephatt, Comrn. Inorg. Chem. 2 (1982) 69.
121 T. A. Manuel, S. L. Stafford, F. G . A. Stone, J. Am. Chem. Soc. 83 (1961)
[31 H. H. Hoehn, L. Pratt, K. F. Watterson, G . Wilkinson, J. Chem. Soc.
1961, 2738.
[4] Recently, this compound was generated photochemically and detected
by IR spectroscopy in an alkane matrix at 77 K: J. C. Mitchener, M. S.
Wrighton, J. Am. Chem. Soc. 105 (1983) 1065.
[5] A. Stockis, R. Hoffmann, J . Am. Chem. Soc. 102 (1980) 2952.
[6] E. Lindner, H.-J. Eberle, Angrw. Chem. 92 (1980) 70; Angew. Chem. Inf.
Ed. Engl. I9 (1980) 73; E. Lindner, G. von Au, H.-J. Eberle, Chem. Ber.
114 (1981) 810.
171 Triclinic crystals of Zb (space group P i ) from n-butane. Refinement in
the non-centrosymmetric space group PI did not lead to a n improvement of the structure model and confirmed the assumption of a disorder
of atoms C(6) and C(7). Lattice constants at 183 K (MoKa radiation):
a=969.4(4), b=976.4(6), c = 1348.9(5) pm, a= 103.75(5), p= 108.77(3),
= 1.352 g/cm'. Structure solved with MULy=70.16(3)", 2 = 2 ,
TAN, R = 0.039, 3833 reflections with 12 3 u(0. Monoclinic crystals of
3b (C2/c) from n-pentane. Lattice constants at 193 K (MoKa radiation):
a=2350.4(3), b=1425.4(3), c = 1917.1(5) pm, p=140.99(4)", Z=8,
pC.,. = 1.414 g/cm'. Structure solved with MULTAN, R =0.039, 1639 reflections with I>3u(I). Further details on the crystal structure investigations can be obtained from the Fachinformationszentrum Energie Physik Mathematik, D-7514 Eggenstein-Leopoldshafen 2, by quoting the
depository number CSD 50942, the names of the authors, and the journal citation.
[8] Procedure: A solution of 10 mmol (F3CSO'CH2CH& o r (F,CS0,CH2)2
in 150 m L dimethyl ether is added dropwise at -50°C to a suspension
of l a , b (10 mmol) in 100 mL dimethyl ether. After 12 h, the dark red solution is concentrated to a third at -80°C in vacuo and diluted with nbutane to the original volume. After the residue is decanted off, the solution is concentrated in vacuo until the colorless (Za, 3a) or yellow (Zb,
3b) compounds precipitate; purification follows by recrystallization
from n-butane (Za, 3a: -78°C) and n-pentane (2b, 3b: -2S"C), respectively. Yields 60-90%.
191 a) C. Kruger, Y:H. Tsay, Sfnrcr. Cornrnun. 5 (1976) 215; b) M. R.
Churchill, H. J. Wasserman, H. W. Turner, R. R. Schrock, J. A m . Chem.
Soc. 104 (1982) 1710.
[lo] F.-W. Grevels, D. Schulz, E. Koerner von Gustorf, Angew. Chem. 86
(1974) 558; Angew. Chem. In,. Ed. Engl. I3 (1974) 534.
[Ill a) H. D. Murdoch, E. Weiss, ffelu. Chim. Acta 46 (1963) 1588; b) D. D.
Beach, W. L. Jolly, Inorg. Chem. 22 (1983) 2137.
[12] a) M. I. Davis, C. S. Speed, J . Organomel. Chem. 21 (1970) 401; b) T. A.
Albright, R. Hoffmann, J. C. Thibeault, D. L. Thorn, J . Am. Chem. Soc.
I01 (1979) 3801; c) T. A. Albright, Tetrahedron 38 (1982) 1339.
Novel Host Structures for the Selective Inclusion
of Aromatic and Aliphatic Guests in Aqueous
By Fritz Vogtle* and Walter M. Miiller
Tetraammonium salts of the [n.l.n.l]cyclophane type 1
(m= 1-3, X or R1-R4 may contain an N') with units derived from diphenylmethane form an elongated cavity and
are suitable, water-soluble host structures for neutral aromatic guest molecules['1.
/ \
Fig. 2. Molecular structure of 3b in the crystal. Selected distances [pm] and
angles ["I: Fe-C5 209.5(7), Fe-C6 210.2(7), C5-C6 139.8(8); Fe-C5-C6 70.8(4),
Fe-C6-C5 70.3(4), C5-Fe-C6 38.9(2), C2-Fe-C3 112.213).
[*] Prof. Dr. F. Vogtle, W. M. Muller
Received: May 21, 1984;
revised: July 10, 1984 [Z 841 IE]
German version: Angew. Chem. 96 (1984) 727
0 Verlag Chemie GmbH. 0-6940 Weinheim, 1984
Institut fur Organische Chemie und Biochemie der Universitat
Gerhard-Domagk-Strasse I, D-5300 Bonn 1 (FRG)
[**I Frau 0. Werner is thanked for her assistance
0570-0833/84/0909-0712 $ 02.50/0
Angew. Chem. Int. Ed. Engl. 23 (1984) No. 9
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synthesis, faciles, reactive, highly, ferracycloalkanes
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