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Cobaltaheterocycles by [3+2]-Cycloaddition of an Acetimidoylcobalt Complex with Acetone and Acetonitrile.

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was recently extended by the synthesis of the isocyanide
complexes C5H5M(PMe3)CNR (M = Co, Rh; R =Me, tBu,
Ph)'']. Since the donor-acceptor properties of isocyanides
and CO are similarl4I, we expected that the reactions of
C5H5M(PMe3)CNR,e. g. with iodomethane, would proceed
analogously to those of the carbonyl complexes
C5H5M(PMe3)C0(M = Col3"],RhI51).
This expectation is fulfilled in the case of the methyl isocyanide-rhodium complex (1). Reaction with iodomethane
in pentane initially yields initially the salt-like compound
(Z), which on stirring in acetone ( 4 h, 50 "C) is transformed,
with migration of the methyl group from the metal to the isocyanide carbon, into the acetirnidoyl complex (3)
novel species. Experiments on the direct ESR spectroscopic
detection should also clarify whether the unpaired electrons
in (14a) and (15a) are delocalized in the sense of (Z4b) and
(15b), respectively.
Received: September 11. 1980 [Z 721 IE]
German version: Angew. Chem. 93, 302 (1981)
-
I
I
He1
Rh
Rh
(pentane)
CAS Registry numbers:
131, 64253-02-7: 140). 76916-00-2; (4b), 76916-01-3: f5), 76916-02-4, (6). 7698483-3: (7aJ. 76916-03-5: (76). 76916-04-6 (81, 76916-05-7: (9). 64253-00-5: (loo),
76916-06-8; (1ObJ. 76916-07-9, ( l l ) ,76916-08-0; (12). 76916-09-1
Me3P'
[ I ] a) D. Ginsburg: Propellanes, Structure and Reactions. Verlag Chemie,
Weinheim 1975; h) A . Greenberg. J F. Liebmant Strained Organic Molecules. Academic Press, New York 1978, pp. 342ff.
121 R. C. Fort. Jr. in C A. Oloh. P o R. Srhlever: Carbonium Ions. Val. 4 Wiley-Interscience, New York 1973. p. 1783.
131 T. Y. Luh, L. M . Sfock. J. Org. Chem. 43. 3270 (1978), and references cited
therein.
14) See [ 1 h], p. 360 f.
151 P. Gohrz, A. de Meoere. Angew. Chem. 84, 892 (1977): Angew. Chem. Int.
Ed. Engl. 16, 854 ( 1 977).
[6] E. S. Huyser in S. Pofoir The chemistry of the carbon-halogen bond. Vol. 1.
Wiley, New York 1973, p 549.
171 G. A . Oloh. Angew. Chem. 85, 183 (1973); Angew. Chem. lnt. Ed. Engl 12,
173 (1973).
IS] A de Meijere, 0.Srhollner, Angew. Chem. 85, 400 (1973). Angew. Chem.
Int. Ed. Engl. 12. 399 (1973).
191 High-pressure mercury vapor lamp SP 500 W (Philips GmbH, Hamburg)
[lo] In collaboration with Dr. K . U. Ingold, National Research Center. Ottawa
'CNMe
Me3P'/
'CNMe
1
NMe
(3)
The first step in the reaction of the methyl isocyanide-cobalt complex (4) with iodomethane probably proceeds analogously to that of (1). A yellow solid is obtained whose IR
C,H5C<-Me
PMe3
I
I
PMe3
C5H5Co-Me
' C NMe
PMe3
I . acetone
C5H5C/
Cobaltaheterocycles by [3 + 21-Cycloaddition of an
Acetimidoylcobalt Complex with Acetone and
A~etonitrile['~
CNMe
2 AgPF,
PF6
(6)
(4)
By Helmut Werner, Bernd Heiser, and Alfred Kiihn"]
Dedicated to Professor Alfred Roedig on the occasion of
his 70th birthday
4C;,.
The series of Lewis-base half-sandwich compounds of the
CO, CSr31)
type C5H5Co(PMe3)L(L = PMe,, PPh3, P(OR)3121,
Me
.
Table I . Spectroscopic data of the reaction products ('H-NMR: 6 values. TMS int J In Hz; IR nujol, values in cm
Complex
'H-NMR
Solvent
CJH~
(21
(CDs),CO
5.80 "1"
JK~
= JH~=H
0.6
1.85dxd
(CDdzCO
(6)
CD3N02
(7)
CDSNO2
f9J Icl
(CDsWO
5.43 d x d
Jnh~=0.6
Jp~=1.6
5.17 d
Jp,, = 0.5
5.30 d
JP" =0.5
7
1.78dxd
J R ~ =
H 0.9
J P H = 11.5
1.57 d
J p p , = 11 .I
1.55 d
J P H = 1 1.8
5.19 d
=0.4
JPH
JpH
-I).
2200
2203
3.03
0.73 d (X=Co)
J p i j = 3.0
3.33 (br) [b]
1.37 s
130s
3.14 s
2.2Os(X=C)
Id1
3.20
3.41
1.44 d
= I I .5
17)
0.83 d x d ( X = Rh)
JR~H=I.I
JPH
= 2.5
2.87 (br) (X=C)
3.75
J R ~= H
I .O
J p t r = 11
(3J
'Me
1560
[a] Relative to broad signal, except in the case of (9). [h] Signal of the methyl group on the C-atom ~1to cobalt. [c] Protons of the exocyclic CH2-group give rise to two doublets ofdoublets at 6=5.01 (JpH=4.4.JHH=2.5Hz)and 4.59 (JPH=3.2, JHH=2.5).[d] Three bands for u(CN) and "(CC) at 1610, 1570, and 1520 cm- I
r] Prof. Dr. H. Werner. Dip1.-Chem B. Heiser, Dr. A. Kiihn
Institut fur Anorganische Chemie der Universitat
Am Huhland. D-8700 Wiirzburg (Germany)
300
0 Verlog Chemie GmbH, 6940 Weinheim. 1981
spectrum [ v(CN) = 2203 cm - I , in nujol] is consistent with
the composition (5). The complex (5) is unstable in solvents
such as CH,NO, or CH2C12,but can be converted into the
0570-0833/81/0303-0300
S 02.50/0
Angew. Chem. Ini. Ed. Engl. 20 (1981) No. 3
yellow, air-stable salt (6) with AgPF6 (in CH2Cl2).Treatment
of (5) with acetone leads to precipitation of a brown, microcrystalline powder which, according to elemental analysis, is
formally a 1 1 adduct of acetone and (5) On the basis of 'HNMR data (Table I ) we ascnbe the hexafluorophosphate
formed on reprecipitation with AgPF6 the structure (7)
The compound (5) also reacts with acetonitrile in the same
fashion as with acetone. Possibly the initial product formed
in the reaction is the compound (8),analogous to (7), which
very rapidly forms the tautomeric complex (9) The corresponding PF, salt IS obtained on reaction with AgPFh (in
CH,NO,) or on addition of acetonitrile to (7)
I
1
Me
Me
(8)
(9)
The structure of the cation of (9) is shown in Figure 1. The
cobalt-containing heterocycle is completely planar (maximum deviation of the atoms from the ring plane 1 pm). and
the C-atoms C11, C12 and C13 also lie in the ring plane. The
presence of the exocyclic double bond is confirmed by the
length of the C10-C13 bond (134 pm). On the basis of the
relatively small difference in the C9-N1 and C9-N2 bond
lengths the positive charge in the NCN fragment of the ring
should be delocalized.
Acetone and acetonitrile have only slightly activated multiple bonds and are therefore generally not capable of unThe observation that the
dergoing [3 + 2]-~ycloadditions~'~.
acetimidoylcobalt group formed by the electrophilic attack
of Me1 at the Co-CNMe bond of (4) rapidly reacts both
with MeZC=O as well as with MeC-N points to a high nucleophilicity of the acetimidoyl N-atom, probably owing to
the electron supply of the electron-rich C5Hs(PMe3)Cofragment.
Received. July 18, 1980 [Z 724 IE]
German version Angew Chem 93. 305 (1981)
c 12
Fig. I . Structure of the cation of (9) in the crystal. with bond lengths [pm] and
bond angles ["I.
CAS Registry numbers:
( I ) . 77097-48-4; (2). 77097-49-5. (3), 77097-50-8; (4). 77097-5 1-9; (5). 77097-52-0.
(6). 77097-54-2. (7). 77097-56-4; (9).77097-57-5: me,Cz=O, 67-641; mel, 74-884.
[ I ] Basic Metals, Part 27. This work was supported by the Deutsche Forschungs-
[2]
131
[4)
[5]
161
gemeinschaft, the Fonds der Chemischen Industne. and by BASF AG. Ludwigshafen, and DEGUSSA. Hanau.-Part 26: S. Lorr, B. Heiser. H. Werner,
J . Organomet. Chem., in press.
H. Werner, W Hofmann, Chem. Ber 110. 3481 (1977); K. Leonhard, H.
Werner, Angew. Chem. 89, 656 (1977); Angew. Chem. Int. Ed. Engl. 16, 649
(1977); B. Juthani. Dissertation. Universitat Wiirzburg 1980
a) A . Spencer, H. Werner, J. Organomet. Chem. 171. 219 (1979); b) H. Werner. 0.Kolb. Angew. Chem. 91. 930 (1979); Angew Chem Int. Ed. Engl. 1 X .
865 (1979).
F. A . Cotfon, C Wilkrnsont Anorganische Chemie, 3rd Ed. Verlag Chemie,
Weinheim 1974, Chap 2 2 Advanced Inorganic Chemistry. 4th Ed. WileyInterscience. New York 1980, Chap. 25.
H. Werner, R. Feser, Angew. Chem. 91, 171 (1979); Angew. Chem. Int. Ed.
Engl. 18. 157 (1979).
Crystallographic data: space group P2,/c, a = 12.595(5), b= 8.573(4).
c = 15.867(5)
p=98.03", V=1696
Z = 4 , p,,,,=1.66, p = 1.68 g/cm';
P2,, MaK,.).solution by direct
1592 independent reflections ( 2 0 ~ 4 0 "Syntex
.
methods (SHELX), refinement to R =0.037 (anisotropic temperature factors).
R. Huisgen, Angew. Chem. 75, 604 (1963); Angew. Chem. Int. Ed Engl. 2.
565 (1963).
A.
I71
A',
BOOK R E V I E W S
The Biosynthesis of Mycotoxins. Ed. by P. S. Steyn. Academic Press, New York 1980. x, 432 pp., bound, $ 44.00.
A clear distinction must always be drawn between primary
and secondary metabolism. Primary metabolism is absolutely essential, while secondary is not. In secondary metabolism
a very wide range of compounds is synthesized (without aim
or purpose?) and we can regard this area as a "playground
for evolution". From a consideration of their mode of action,
the secondary metabolic products which are synthesized by
microorganisms and which inhibit or kill microorganisms are
known as antibiotics. To them has recently been added the
large group of mycotoxins, the toxic secondary metabolites
of fungi. The particular interest in this group of substances
started at the beginning of the sixties with the discovery of
aflatoxin, a metabolic product of Aspergillus flavus and AsAngew Chem In! Ed. Engl 20 (1981) N o 3
pergillus parasiticus that turned out to be a highly active carcinogen. It is not surprising that since then the analysis of
this class of substances has been worked out very thoroughly
and a firm recommendation has been made to destroy all
moldy food.
The present work is an excellent survey of the latest stage
of research into the biosynthesis of mycotoxins. The first paper, by Bu'Lock, gives an introduction to the field that is well
worth reading. The summary reports are written by authoritative experts: Floss reports on the biosynthesis of the ergot
alkaloids, Tamm on the biosynthesis of trichothecin mycotoxins and cytochalasines; Steyn, VIeggaar and Wessels provide an important contribution on aflatoxins, B. Franck reports on the biosynthesis of ergochrome, and Yamazaki on
neurotropic mycotoxins; Lolita Zamir on patulin and penicil-
301
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complex, cycloadditions, acetonitrile, acetone, cobaltaheterocycles, acetimidoylcobalt
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