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Bis(olefin)nickel(0) Complexes.

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which sulfur is spontaneously eliminated. Thiaziranes
have recently been
as reactive intermediates
in the photochemical rearrangement of thiazoies[61and
isothia~oles['*~~,
but are as yet unknown.
[8] 1.P. Carteau, A . Lablanche-Combier, and A. Pollet, Chem. Commun. 1969,1018.
[9] Prepared in the standard manner-details to be reported.
[ l o ] J. B. Bapat and D. Sr. C . Black, Austral. J. Chem. 21,2507 (1968).
[ I l l R. P . Linstead and E. M . Meade, J. Chem. SOC. 1934,935; W E .
Grigsby, J . Hind, J . Chanley, and F. H . Westheimer, J. Amer. Chem. Sot.
64,2606 (1942).
1121 F. G. Riddell, J . M . Lehn, and J . Wagner, Chem. Commun. 1968,
1403.
H
Bis(olefin)nickel(O)Complexes
By P. W Jolly, 1. Tkatchenko, and Giinther Wilke"]
The observation"] that in 1,5,9-cyclododecat~enenickel(0) (CDT. Ni), for example, the all-trans-CDT can
be exchanged for atl-cis-CDT led us to attempt to replace
the CDT in CDT-Ni.phosphane complexes by other
olefins. We report below the preparation and characterization of the new types of bis(olefin)nickel(O) complexes
(1) -(3).
(3)
(41
The reaction of oxaziranes with sulfur-containing nucleophiles is influenced by stereochemical factors to a certain
extent. For instance, 2-tert-butyl-3-methyloxazirane
(1 b)[91
remained unchanged in the presence of thiourea after
twelve hours at room temperature; more vigorous conditions led to extensive tar formation. However, various
fused bicyclic oxaziranes were smoothly converted to
the related imines. In contrast to (I b), 2,2-dimethyl-3phenyl-6-oxa-l-azabicyclo[3.1.O]hexane (Za) [''I was completely deoxygenated after reaction for eight hours at
room temperature. The more hindered oxaziranes (2 b)['*]
and ( 2 ~ ) ' ~required
'
a reaction temperature of 80°C for
five hours for complete deoxygenation, while compound
(2d)"'I was only totally converted to the imine after
twenty eight hours at 80°C.
In general, the behavior of fused bicyclic oxaziranes is
similar to that of simple ones, in marked contrast to the
behavior of some fused oxiranes. Cyclopentene oxide is
particularly resistant"] to any reaction with thiourea
or potassium thiocyanate. This result is consistent with
the necessary formation of an unfavorable" 'I transfused bicyclic intermediate, e.g. (3), according to the
postulated mechanistic pathwayf2- 31. However, in the
case of bicyclic oxaziranes,a cis-fused bicyclic intermediate,
e. g. (4),can always be formed, as a consequenceof inversion
of configuration at the nitrogen atom, even if such inversion
is
Received: February 15. 1971 [Z 367 I E ]
German version: Angew. Chem. 83,355 (1971)
[l] C. C. J . Culuenor, W Dauies, and K . H . Pausacker, J. Chem. SOC.
1946,1050.
[ 2 ] E. E . van Tamelen, J. Amer. Chem. SOC. 73, 3444 (1951).
[ 3 ] C. C . J . Culuenor, W Dauies, and W B. Sauige, J. Chem. SOC. 1952,
4480; C. C. Price and P. F. Kirk, J. Amer. Chem. SOC. 75, 2396 (1953);
F. G. Bordwell and H . M . Andersen, ibid. 75,4959 (1YS3).
[4] C . C . J . Culuenor, W Davies, and N . S. Heath, J. Chem. SOC. 1949,
278.
[ 5 ] W D. E m m n s , J. Amer. Chem. SOC. 79, 5739 (1957).
[ 6 ] M . Kojima and M . Maeda, Chem. Commun. 1970,386.
[ 7 ] M. Ohashi, A . Iio, and 7: Yonezawa, Chem. Commun. 1970, 1148.
328
+ 2 Olefl"
-a/
\-R
L-Ni
A f
ItDYCB
kT
1
1
=L
L-- N i
-CDT
3
L-Ni
(3)
(21
L=P(C,H,,), for ( l a ) , R = H ; ( l b ) , R = C H , ; ( l c ) ,
R=3-cyclohexenyl; (2); and (3). L = P(C,H,), for ( I d ) , R = H
( l a ) is
formed in 80-90% yield as an almost white precipitate
when ethylene is passed into an ethereal suspension of
all-trans-I ,5,9-cyclododecatrienetricyclohexylphosphanenickel ( 4 ) at -20°C. (I a) reacts with triphenylphosphane
at 80°C with displacement of the theoretical amount of
ethylene. The structure of ( l a ) is proved by the IR
spectrum [v(C=C) at 1490 cm-'1 and the 'H-NMR
spectrum(z = 7.22/s, W,,, = 4Hz)(cf. [(C6Hll),P],NiC2H,,
singlet at z = 7.949.
Tricyclohexylphosphanebis(ethylene)nickel(O)
The complexes ( 1 b) and ( I d ) are prepared analogously.
The 'H-NMR spectrum of the propene complex ( l b )
[G(C=C) = 1485 cm-'1 shows that several isomers are
present in solution. The exchange reaction between propene and (C,H,),PNi-CDT
at -20°C leads only to
separation of metallic nickel. The propene in ( l b ) is
readily replaced on reaction with ethylene, with formation
of (la).
(Ic) and (2) are formed on reaction of ( 4 ) with vinylcyclohexene or divinylcyclobutane (DVCB), respectively,
in ether at -20°C. Both these compounds, which are
white powders and extremely sensitive to air, react with CO
at -78°C with quantitative replacement of the vinylcyclohexene or divinylcyclobutane.
[*] Dr. P.W. Jolly, Dr. I. Tkatchenko, and Prof. Dr. G. Wilke
Max-Planck-Institut fur Kohlenforschung
433 Miilheim-Ruhr, Kaiser-Wilhelm-Platz 1 (Germany)
Angew. C h e m . internat. Edit.J Vol. 10 (197i) J N o . 5
The bis(l,3-butadiene) complex (3) is obtained as a
yellow, sparingly soluble compound having a somewhat
sweet smell on interaction of ( 4 ) with liquid butadiene
for 3 days at -20°C. Replacement of the butadiene from
( 3 ) by triphenylphosphane at 80 "C is not quantitative:
only 63-65% of the calculated amount of butadiene is
found, and vinylcyclohexene, 1,5-cyclooctadiene, and
divinylcyclobutane in the ratio 26:6:1 are also formed.
( 3 ) can also be obtained from [(C,H,,),P],Ni and
butadiene, a compound (C,H, ,),PNi .C4H6[41
apparently
being formed as intermediate; however, the nitrogen
complex, [[(C,H, 1)3P],Ni],N,[31 in toluene affords a
product of composition [[(C,H, l)3P]Ni .C4H,], . toluene.
If ( 3 ) is treated with ( 4 ) , a sparingly soluble dimer,
probably [(C,H, l)3P.Ni .C4H,J2, is precipitated. (For
other properties of (2) and ( 3 ) and their relation to the
mechanism of dimerization of butadiene on nickel-ligand
catalysts see ref.15J.)
Experimental:
Ethylene is passed into a suspension of ( 4 ) , L = P(C,H '),
(2.85 g, 5.7 mmole) at -20°C until the color changes from
orange to almost white (4 h). The precipitate ( I a ) is filtered
off at - 50 "C, washed three times with ether, and dried in
a high vacuum (yield 2.0 g, 90%).
cis-Divinylcyclobutane (1 ml) is added dropwise to a
suspension of ( 4 ) , L = P(C6H, ,), (3.55 g, 7.1 mmole) in
ether at - 20 "C. The mixture is stirred for 3 days at - 20 "C
and then cooled to - 50 "C. The ether is removed and the
white product (2) is washed three times with ether and
dried in a high vacuum (yield 2.85 g, 90%).
to the stereochemistry of the isomers obtained from the
cyclodimerization of substituted butadienesC3! For some
time now we have held the view that the dimerization
is a multi-step process involving, among other intermediates, an r,w-bi~allyl-C,-chain~~~.
The isolation of (C,H,,),P.Ni.DVCB
( I ) and
(C,H, 1)3PNi(C4H6)2(2)['] has presented the possibility
of investigating this question experimentally and of
showing that a multi-step process is involved
Bis(butadiene)tricyclohexylphosphanenickel(O) ( 2 ) , a relatively thermally stable yellow compound, reacts with
excess triphenylphosphane at 80°C to give only 65% of the
expected butadiene, the remainder being dimerized. In
contrast the reaction in solution with CO at -78°C
gives exclusively vinylcyclohexene (VCH).
( I ) reacts with CO at -78°C to produce DVCB. If the
same reaction is carried out with a sample which is first
left in solution at room temperature for an hour one
obtains exclusively VCH. (2) may be recovered unchanged
from a toluene solution; under the same conditions ( I )
partly rearranges to (2).
From these observations it may be concluded that ( I )
and (2) rearrange in solution to a common intermediate.
Evidence for this is given by the 'H-NMR spectra of
solutions of (1) and (2) in cyclohexane-identical
spectra are obtained which are in agreement with a
a-allyl-o-ally1 structure ( 3 ) [NMR :T =4.35 (H '/2 triplets,
J l , 29 Hz. J , , = J , , 3 , 9 Hz); 5.28 (H2/2triplets, J , , 9 Hz;
J,, 4 = J 2 , p 7 Hz); 5.88 (H '12triplets, J S , , 8 Hz; J s , =J 5 ,
12 Hz) intensity 1 :1 :I].
Received: February 15,1971 [ Z 368a IE]
German version: Angew. Chem. 83, 328 (1971)
[I] K.Jonas, P. Heimbach, and G. Wlke,Angew. Chem. 80,1033 (1968);
Angew. Chem. internat. Edit. 7,949 (1968). K.Jonas, Dissertation, Universitat Bochum 1968.
[2] a) G. Wfkeand G. Herrmann, Angew. Chem. 74,693 (1962); Angew.
Chem. internat. Edit. I , 549 (1962); b) G. Herrmann, Dissertation, Technische Hochschule Aachen 1963.
[3] P. W Jolly and K . Jonas, Angew. Chem. 80, 705 (1968); Angew.
Chem. internat. Edit. 7, 731 (1968).
[4] K. Jonas and P. W Jolly, Proc. 4th Intern. Conference Organometal. Chem., Bristol 1969, S. 8.
[5] P. W Jolly, I . Tkatchenko, and G. M.Flke, Angew Chem. 83, 329
(1971); Angew. Chem. internat. Edit. 10,329 (1971).
(C6Hll),P-Ni
(2)
=L
- 78 OC
DVC B
VCH
(3)
The Mechanism of the Cyclodimerization
of Butadiene with Nickel-Ligand Catalysts
By P . W Jolly, I . Tkatchenko, and Giinther Wilke"]
It has been frequently postulated that the transition metal
catalyzed cyclooligomerizations of acetylene, 1,3-dienes,
and olefins as well as the dismutation of olefins are concerted processes['! In particular the dimerization of
butadiene to divinylcyclobutane (DVCB) with a nickelligand catalyst has been suggested to occur by a concerted
mechanismc2].This formulation, however, is in contrast
I'[
Dr. P. W. Jolly, Dr. I. Tkatchenko, and Prof. Dr. G. Wilke
Max-Planck-Institut fur Kohlenforschung
433 Miilheim-Ruhr, Kaiser-Wilhelm-Platz 1 (Germany)
Angew. Chem. internat. Edit. 1 Vol. 10 (1971)
1 No. 5
Under the influence of an accelerating ligand (e.g.CO)
ring closure occurs with formation of VCH (cf. the analogous reaction of C ,-bis(R-ally1)nickel with COL6').
It is also noteworthy that at room temperature in the
solid state ( I ) rearranges to (2). This shows itself as a
color change from white (1) to yellow ( 2 ) , as a decrease
in the intensity of the 1482 cm- band (coordinated C=C)
and increase in the intensity of the 1600cm-' band
(free C=C) of (2), as well as in the products obtained by
reaction with triphenylphosphane at 80°C ; the volatile
hydrocarbon products obtained from freshly prepared
( l a ) and from two months old ( I b ) have different compositions.
'
( l a ) : cC,=74%, DVCB:VCH:COD=3.6.1.8:1 as well as 26U/,C4H,
( I b ) : c C , = 6 2 % , DVCB:VCH:COD=4.7:4.3:1 as well as 38% C4H,
329
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