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Nickel-Induced Coupling and Cleavage of CC-Bonds.

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of this type can be isomerized under mild condition^^"^;
this also occurs with l-methyl-2-phenyl-, 1,2-dimethyl-1phenyl-, and 2-methyl-l,l-diphenylcyclopropane,as well
as with 2-methyl-spiro[cyclopropane- 1,9'-fluorene].
Nickel-Induced Coupling and Cleavage of CC-Bonds
By Heinz Hoberg and Antonio Herrera"]
Nickelacyclopentenediones (I), which yield cyclobutenedione derivatives with maleic anhydride (MA) at 20°C via
a CC, coupling reaction, are formed from 2,2'-bipyridine
(bpy)-stabilized nickel(o) compounds, carbon monoxide,
and disubstituted alkynes (R=alkyl, aryl)"]. In order to
gain a detailed insight into the CC-coupling step (1)-(2)
we used ligands other than MA for the reductive elimination (NiZc-P Ni').
Using CO as the reducing agent, an intermediate species
could be isolated and hence the CC-coupling and
-cleavage reactions rendered reversible.
A solution of ( I ) (R=C6HS) in toluene at 80°C first
takes up an equivalent of CO, whereby the carbonyl C
atoms couple. Compound (3) is formed, in which the complex-bound (2) is present.
(2) is only liberated under a higher CO partial pressure
(10 bar) at 80°C, and simultaneously forms (bpy)Ni(CO),
and, to a lesser extent, Ni(CO),.
Received: March 16, 1981 [Z 878 IE]
German version: Angew. Chem. 93. 923 (1981)
CAS Registry numbers:
&(I), 25181-26-4; &(I). 7653-95-4; cc-(I), 7693-96-5; tt-(l) K + , 79171-33-8;
ct-(l) K +,7917 1-34-9; cc-(1)7 K +,7917 1-35-0; (4) - K +,79101-7 1-6; (6).
79101-72-7; (7)2-2K+, 79121-03-2
[I] a) Summary: J. A. Berson, L. D. Pedersen, B. K . Carpenter, J. Am.
Chem. SOC.98, 122 (1976); b) Summary: S . S. Hixson, Org. Photochem.
4, 191 (1979); see also: H . D. Roth, M. L. M . Schilling, J. Am. Chem.
SOC. 102, 7958 (1980).
121 G. L. Closs, R. A. Moss,J. Am. Chem. SOC.86, 4042 (1964).
131 Gas chromatographic analysis (SE 30, 1.5 m, 145°C); error f 1%.
141 Deprotonation at C' and/or at C2 by Na/K alloy, which is faster than at
C', must be excluded. Likewise, bond breaking between C ' and C2 is energetically much more unfavorable, since the trimethylene radical anion
formed is not stabilized by the phenyl substituent.
[5] The rate at which the equilibrium tt-(I)+ct-(I)+cc-(I) is established and
the rate of formation of the secondary products (4)-K+, (6), and
(7)'-2K' is also a function of the stirring rate in these heterogeneous
161 2-Methyl-1-phenylbutane (from the protonation of (4)- K +) is identical
with the sample described by D. Dolphin. 2. Muljani, J . Cheng. and R.
B. Meyer (J. Chem. Phys. 58, 413 (1973)). 3-Methyl-4-phenylhexane (6)
was synthesized independently; the structure was proven by CH analysis, as well as by mass- and 'H-NMR-spectroscopy.
171 See e.g. E. Buncel: Carbanions: Mechanistic and Isotopic Aspects, Elsevier, New York 1975. The spontaneous protonation of tertiary alkylpotassium compounds in THF also excludes the isomerization of the dianion intermediate.
[8] A similar reaction of a benzyl anion with ethylene from THF has recently been reported: M . Schlosser, P. Schneider, Helv. Chim. Acta 63,
2404 (1980). G. Decher and W. E. Russey, Juniata College, Huntington,
Pennsylvania 16652, USA are thanked for a compilation of literature o n
closely related reactions.
[9] The description of the trimethylene radical anion (Z):K+ shown in
Scheme I only uses one of the two mesomeric structures. A MNDO
study (Dr. H. U.Wagner. Universitst Miinchen, unpublished results) indicates that the 1-phenyltrimethylene radical anion has a 0.90-arrangement and carries a considerable negative charge not only on C ' but also
on C':
Prof. G . Spiteller, Universitl Bayreuth, is thanked for recording and interpreting the spectra.
a) L. L. Miller, L. J. Jacoby. J. Am. Chem. SOC.91, 1130 (1969); b) S. W.
Staley, J. J. Rocchio, ibid. 91, 1565 (1969); c) 0. M. Nefedov. N. N. Nouitsknya, A. D. Petrov, Dokl. Akad. Nauk SSSR 152. 629 (1963); d) T.
Norin, Acta Chem. Scand. 19, 1289 (1965); e) M . G. Dauben. E . I . Deuiny, J. Org. Chem. 31, 3794 (1966); 9 H . 0. House, C. J. Blankley. ibid.
33, 47 (1968); g) H . E. Zimrneman. K . G. Hancock, G. C. Licke. J. Am.
Chem. SOC.90, 4892 (1968); h) H. M. Walborsky. J. B. Pierce, J. Org.
Chem. 33, 4102 (1968); i) H . M. Walborsky, M . S. Aronoff. M. F. Schulman, ibid. 36. 1036 (1971); j) Prof. H . M. Walborsky has made available
to us on June 22, 1981 the paper in print H . M . Walborsky, E. J. Powers,
Cyclopropanes. Part XLI. Electron Transfer From Lithium Metal Surfaces to (5)and ( -)-(S)-l-fluoro-l-methyl-2,2-diphenylcyclopropane,
Isr. J. Chem. The chemistry described herein goes back to E. J. Powers,
Dissertation, Florida State University 1969. We are very grateful to Professor Walborsky for informing us about this work.
This is in contrast to an observation made by Staley 11lb], who in the reduction of cis-1-methyl- and trans-1-methyl-2-phenylcyclopropane
lithium, in ammonia, obtained the corresponding cleavage products in
markedly different ratios.
(131 Phenyl cyclopropanes isomerize thermally at ca. 300°C [la]
0 Verlag Chemie GmbH. 6940 Weinheim. 1981
(3) could also be obtained by reaction of (2) with
(bpy)Ni(CO), by CO cleavage at 20"C, and from (4) by
reaction with CO. (4) is formed from the reaction of (2)
with (bpy)Ni(cod), (cod = 1,5-cyclooctadiene) (Scheme 1).
(3) crystallizes in red leaflets and is diamagnetic. The
mass spectrum only contains the fragment ions m / z 156
(bpy), 178 (tolan) and 234 (2). The IR spectrum (KBr)
shows characteristic bands at 2000 cm-I (Ni-CO) and in
the >C=O region at 1680 and 1660 cm-'. Hydrolysis (2 N
H2S04, 20 "C) yields (2).
The CC-coupling (1)- (3) is reversible: upon heating to
ca. 15O"C, the complex-bound CO cleaves off. Nickelacyclopentene is re-formed in an oxidative addition reaction
(Ni*+ NiZ+transition). ( I ) is also formed from the CO-free
(4) in 3 h at 100°C.
The X-ray structure analysisiz1 shows that the
(CO)Ni(bpy) fragment in (3) is bonded to the CC double
bond of the system (2) in such a way that the bpy lies
above the carbonyl groups, whereas the CO ligand lies on
the same side as the phenyl moieties (Fig. 1).
(3) from ( I ) : (I) (4.04g, 8.99 mmol) (R=C6H$'I) is suspended in 50 mL of toluene and takes up 200 mL (9.0
[*I Prof. Dr. H. Hoberg, Dr. A. Herrera
Max-Planck-Institut fur Kohlenforschung
Postfach 01 1325, D-4330 Miilheim an der Ruhr 1 (Germany)
0570-0833/81/1010-0876 $ 02.50/0
Angew. Chern. Int. Ed. Engl. 20 (1981) No. 10
mmol) of CO at 80°C and 1 bar within 6 h, thereby forming a red solution. The red crystals, which precipitate after
48 h at room temperature, are filtered off and dried. Yield:
1.68 g (39%) (3).
(2) is also generated by the elimination method developed
by Chan and Massudd'I on reaction of (lef31 and potassium fluoride in dimethyl sulfoxide (DMSO) at 55°C. In
the presence of four equivalents of diphenylisobenzofuran,
(2) could be trapped up to 56% as the already well-known
Diels-Alder adduct (3)L41. Formation of the diene (4)
(l2%)['] in this reaction was unexpected. Reaction of (le),
KF and four equivalents each of anthracene or 9-methoxyanthracene (MOA) in DMSO at 55°C proceeded analogously and yielded a mixture of (5a)I6I(14%) and (6a) (41%)
or o f (5b)"' (24%) and (66) (48%), respectively.
Fig. 1. Structure of (3) in the crystal.
(3) from (2) and (bpy)Ni(CO),: A solution of (2)"](1.1 g,
4.7 mmol) in 20 mL tetrahydrofuran (THF) is dropped into
a solution of (bpy)Ni(C0)2r31
(1.26 g, 4.7 mmol) in 30 mL of
THF at room temperature. The red-violet solution gradually turns red-brown, whereby a precipitate is thrown
down with simultaneous evolution of gas. 95 mL (4.2
mmol) of CO is collected within 6 h, and the precipitate is
filtered off and dried. Yield: 1.78 g (80%) (3).
( I ) from (3):(3) (1.5 g, 3.2 mmol) is suspended in 50 mL
of decalin and heated to 150"C, whereby evolution of gas
is observed. 65 mL (2.9 mmol) of CO is collected within ca.
6 h. The precipitate is filtered-off and dried. Yield: 1.34 g
(95%) (I).
(4) from (2): (2)"l (1.3 g, 5.5 mmol) in 20 mL of THF is
dropped into a solution of (bpy)Ni(cod)[41(1.8 g, 5.5 mmol)
in 50 mL of THF. After 24 h the crystals formed are filtered off and dried. Yield: 2.24 g (91%) (4).
(3) from (4): A suspension of (4) (1.3 g, 2.9 mmol) in 50
mL of toluene takes up 25 mL of CO at 1 bar within 24 h,
whereby a solution is formed. The crystals formed after ca.
6 d at -20°C are filtered off and dried. Yield: 0.48 g
(35%) (3).
Received: March 17, 1981 [ Z 879 IE]
German version: Angew. Chem. 93, 924 (1981)
CAS Registry numbers:
(I). 75507-29-8; (2). 24234-76-2; (3). 79121-09-8; (4).
(bpy)Ni(CO),, 14917-14-7; (bpy)Ni(cod), 55425-72-4
111 H. Hoberg, A . Herrera, Angew. Chem. 92, 951 (1980); Angew. Chem. Int.
Ed. Engl. 19, 927 (1980).
121 C. Kriiger, Y.-H. Tsay, unpublished results.
131 E. Zuhn, Dissertation, Technische Hochschule Miinchen 1959.
I41 E. Dinjus. J . Gorski, H . Walther. Z. Anorg. Chemie 422. 75 (1976).
1,2,3-Cycloheptatriene by Isomerization of
By Hans-Georg Zoch, Gunter Szeimies, Roland Romer,
and Robert Schmitt"]
It has been shown by competition experiments that the
halides (la-c) react with lithium diisopropylamide (LDA)
in tetrahydrofuran (THF) at -20°C to give free tricyclo(4.1.0.O2.']hept-1(7)-ene (2)[11. We have now found that
['I Prof. Dr. G. Szeimies, Dip].-Chem. H . G . Zoch, Dipl.-Chem. R. R6mer,
cand. chem. R. Schmitt
Institut fur Organische Chemie der UniversitBt
Karlstr. 23, D-8000 Miinchen 2 (Germany)
This work was supported by the Deutsche Forschungsgemeinschaft and
the Fonds der Chemischen Industrie.
Chem. fni Ed. Engl. 20 (1981) No 10
(e I
Icl Id)
la), R =
l 71
( b l , R = OCH3
Since the dienes (4) and (6) are not products of the thermal is~merization'~,~]
of the propellanes'(3) and (5). and
since the latter are not converted into (4) and (6) under the
reaction conditions
these products must have been
formed during the reaction itself. The structure of these
dienes would suggest that their precursor is the 1,2,3-cycloheptatriene (7). which is generated according to Scheme 1
by thermal rearrangement of (2) and is trapped as the
Diels-Alder adduct.
Scheme 1.
On lowering the concentration of MOA, the yield of (56)
should decrease, that of (6b) increase. This is in fact the
case: The reaction of (le), KF, and three, two or one molar
equivalent(s) of MOA in DMSO at 55°C afforded
(5b)/(6b)-mixtures of the composition 15% and 54%, 12%
and 6O%, and 8% and 66%, respectively.
The extent of the rearrangement (2)+(7) not only depends on the nature and concentration of the trapping
agent but also strongly on the temperature. Thus reaction
of (le) and K F with tetraphenylcyclopentadienone or 2,5dimethylfuran in DMSO at 100°C afforded only the adducts (8) and (9) (30% and 38%, respectively). Our earlier
works, in which (2) was formed by elimination of HCI
0 Verlag Chemie GmbH, 6940 Weinheim. I981
0 02.50/0
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nickell, bond, cleavage, induced, couplings
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