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Hexamethyl-tris--homotropone from 3 3-Dimethylcyclopropene and Carbon Monoxide.

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The mass spectrum of ( 4 ) shows the molecular ion at
m / ~ = 4 6 0and peaks for the (M-2CO) and (M-4CO) fragments. Additional signals are observed for the
C5H5(C0)2MnP(C,Hs)+,
C,H,MnP(C,H,)+. and P(C,H,)
ions.
The electronic spectrum of ( 4 ) shows an intense absorption
at 1 9 6 0 0 c m - ' ( ~ = 7 0 0 01 nio1-l cm-'),whichdoesnot occur
in complexes of the type CsHs(C0)2MnL (L = phosphane,
amine). As in the case of the arsinidene complex ( I ) ' " ] , we
ascribe this band to an electronic transition in the three-center,
four n-electron system ( 4 a ) to ( 4 ~ ) .
+
The formulas indicate that four electrons from filled manganese d-orbitals are used to complete the octet of the sextet
ligand C,H ,-P:.
141 G.
H~iliiicv.J . I 0 1 1 Sc.i r ~ l M.
. f L f u r \ i / i . and H -C. S ! ~ h i i i i d ,Angex Chem.
S7. 455 (1975); Angeu. Chem. intcrnat. Edit. 14. 434 iI975j.
[ 5 ] R =(!.05: measuremenis: Syntex-P2,; solution: Syntex-XTL.
[ b ] IZ: K. Dniii. G. L. Siniori, P. M . ficichrl. and L. I;. Driiil. J. Organometal.
Chem. 50. 193 (1973): and literature citud therein.
Hexamethyl-tris-o-homotropone from 3,3-Dimethylcyclopropene and Carbon Monoxide
By Paul Bingrr and Ulf Schuch~rdtr"]
3,3-Dimethylcyclopropene ( l ) can be converted quantitatively on phosphane-modified palladium(o)catalysts into hexamethyl-tris-rrcois-o-homobenzene
( 2 ) " . 'I. On the same catalysts hexamethyl-tris-o-homotropone
(4)13' can be prepared
from ( I ) and carbon monoxide in yields of up to 90%.
The homooligomers of ( I ) , compounds (2) and ( 3 ) [ " ] are
,
the only other products formed.
P
(21
I1 =
k?
14)
1-4
- ( gH5
CH(C T13)z
The yield of ( 4 ) depends on the CO concentration as well
as on the temperature and reaction time (cf. Table 1). High
CO concentration and low temperatures favor formation of
(4).
Table I . Dependence of the yield of ( 4 ) on C O concentration and reaction
conditions. In each experiment 8g (0.12molJof ( 1 ) was allowed t o rciict
rn
Catalysr
Fig. I. Structure o f C . H , P [ M I ~ ~ C ~ ) ~ C ~ H , ] ~
A [a1
In full agreement with this the X-ray structure analysis
of ( 4 ) (Fig. l)l5] shows that the phosphorus atom lies in
a plane with its three substituent atoms (Mn, Mn, and Cphrny,)
and that the Mn-P bond lengths are unusually short. They
have a length of 218.4k0.2 pm. whereas Mn-P bond lengths
in the range 226 to 240 pm are observed in manganese-phosphane complexes[h!
The phosphinidene complex (2) is thus the first compound
in which phosphorus(r) has a trigonal planar coordination
and is stabilized by metal-dn-phosphorus-pn bonds.
Received: June 13. 1975 [ Z 3x2 IE]
German version: Angew. Chem. 87.714 (1975)
CAS Registry numbers:
( 2 ) . 55758-70-X: ( 3 ) . 55758-71-93 ( 4 ) . 5634X-60-8
S ~ 1 1 i i 1 i d . AngeM Cheiii. X7. 454 11975): A n & w
Chem. intcrnat. Edit. 14, 433 (1975).
[2] A . E c k r r and L Scliinidr, Chem. Ber. /Oh. 1453 (1973): a n d literature
cited thercin.
[3] C. Hurlnrr. H - D Muller.. 4 Frrinh. and H. Lor.rii=. Angeu. Chem. X7.
597 (1975);Angew. Chem. internat. Edit. 14. 572 (1975).
[I] G Hiiiriiw and I I - G
706
B [b]
B [b]
CO-pressure
[arm]
7
["C]
t
[h]
I
70
70
10
30
60
20
3
3
[".I
12)
Yield
(3)
5
75
7
63
[a] I mmol Pd(acac),, I iiimol P[CH(CH,),],;Zmmol
40mI diethyl ether.
[b] 0.15mmol [(C,H5)2P]1Pd in 20ml benzene.
4
20
(41
20
XY
17
(C2H,),AIOC,H, in
The mixed oligomerization leading to ( 4 ) is, to the best
of our knowledge, the first smooth synthesis of a cyclic ketone
from alkene and CO using a transition metal compound as
a catalyst.
Formation of the tricycloheptane derivative (3) from ( I )
can most probably be attributed to the influence of a Pd
catalyst modified by CO ligands on which ( I ) is transformed
into the 2,2-dimethylvinylcarbene (cf. Ref. [ 5 ] ) .
(3) and ( 4 ) were identified with the aid of spectroscopic
data (IR, MS, 'H-NMR). The 'H-NMR spectrum of ( 4 )
confirms its sq'n,unti,s)in-structure [T = 8.68 (d, 7-H, 9-Hi
J=9.5Hz), 9.59 (d. 1-H, 5-H; J = lOHz), 9.66ppm (s, 2-H,
4-H: J4,sand J t , 2=O)].
[*] Dr. P Binger and Dr. U Schuchardt
Max-Planck-Institiit fur Kohlenforschung
433 Mulheim-Ruhr. Kaiser-Wilhelm-P!atr I (Germany)
E x per imrntal :
Tetrakis(triphenylphosphane)palladium(o)(0.2g, 0.17 mmol)
and ( 1 ) (8g, 0.12mol) are dissolved in benzene (20ml) in
a 60ml V4A steel autoclave and CO is added to a pressure
of 71 atm at -78'C. The autoclave is shaken for 20 h at
30°C. After release of 3.5 N1 of excess C O the autoclave
contains 23.4 g of a yellow solution. After removal of benzene
fractional distillation yields 0.6g of a mixture (b.p. 5 5 6O0C/O.1torr) having the composition (GC): 10.1 % benzene;
25.5:,, ( 3 ) . 56.87,; ( 2 ) ; 2.6':;) (41, and remainder 5.1";,
(2 pcaks). Sublimation of the residue at 100°C (bath temperature)/O.l torraffords 4.3 g of97.6~~~-pure(CC)colorless
( 4 ) [rest
(GC)0.2 '%, (3) and 2 % ( 2 ) ] and at 120°C 2.5 g of 100 %-pure
(GC) ( 4 ) , m.p. 98°C. Total yield of ( 4 ) : 6.7g (89%).
Received: July 4, 1975 [Z 283 IE]
Gcrman version: Angew. Chem. 87. 71 5 (1975)
CAS Registry numbers:
( I i . 3907-06-0: ( 2 ) . s639o-01-3:
r(C,H,),P],Pd, 14221-01-3
( 3 ) . 56348-21-1: (41.
56348-22.2:
The thermal and photochemical decomposition reactions
of (1 c) and ( I t ) yield trans-1,2-divinylcyclopropane(2) and
1,4-~ycloheptadiene(3) (cf. Table I).
Table I. Decomposition products of ( 1 c ) and ( / l ) .
(/c)
[b]
(11)
Yield [ X ]
thermal (0-60°C)
(21
13)
(21
38
37
42
56
62
63
Yield [''I;,]
photochemical [a]
(3)
( P i [cl
56
42
0--2
0--2
[a] 1T-Pcni:iiic. Pqrcx filter. - 5°C.
[b] Calculated from the mixture and pure ( 1 r )
[c] Tentatively assigned a s 1.3.5-hcptatriene.
In contrast to 3,5-dialkyl-substituted 1-pyrazolines, both
[I]
[2]
[31
[4]
[5]
P. Binqrr, G. S<hrorh, and J. McMerkiny. Angew. Chem. 86. 518 (1974):
isomers (1 c) and (1 t ) give similiar yields of (2) and ( 3 ) ,
Angew. Chem. internat. Edit. 13. 465 (1974).
suggesting, with support of recent kinetic e~idence'~],
the forP. Binyrr and U . S h c h o r d r . unpublished.
Systematic
name:
3,3,6.h.lO,10-Hc~amethyl-~!-rl.oriri.,~~~~-tetr;~cq-mation of a stabilized intermediate of extended lifetime ( 4 ) ,
clo[7.1 0 0'.' O5 ']decan-X-onc
which can undergo several rotations before ring closure occurs.
'1.3.7.7-Tclramethyl-5-(l-methyl-1 - p r o p e n ~ l ) - r ~ r i n ~ - t r i c y ~1l .O
o [0'
4 'IhepIn order to test whether (3) is formed ilia path B from
t:me.
cis-l,2-divinylcyclopropane( 5 ) or cia path A from an isomer
P. Bingrr and J . M c M r r k i i t y , Angew. Chem. 86, 518 (1974): Angew.
Chem. internat. Edit. 13, 466 (1974).
of ( 4 ) by direct ring closure, we have studied the low tem-
perature photolysis of ( l c ) and (If) (CDCI,, Pyrex filter,
- SO"C)[41.
The thermal reaction cannot serve this purpose.
(IcJ
Low Temperature Thermal and Photochemical Formation of Diallylic l ,3-Diradicals. Cope Rearrangement
of cis-l,2-Divinylcyclopropane[**'
By Manfred Schneider[*]
The thermal and photochemical decomposition of 3-vinylsubstituted I-pyrazolines leads to products which can be interpreted in terms of allylic 1,3-diradicals['! The decrease in
decomposition temperature (by ca. 100°C) and activation
enthalpy (by 9 kcal/mol) on introduction of a vinyl group
suggests substantial stabilization of an allylic 1,3-diradicaL
1,3-Dipolar cycloaddition of 3-diazo-1 -propene to 1,3-butadiene produces a 45 : 5 5 mixture of cis- and trans-3,S-divinyl-lpyrazolines ( 1 c) and ( 1 f ) , which decompose thermally
around O"C['* '1. The sensitivity of ( 1 c) has so far precluded
separation of (1 c) and ( 1 t), but pure (1 t ) can be obtained
by partial decomposition of the mixture, since at 0°C (1 c)
decomposes faster than ( 1 t) r31.The substantially lower decomposition temperature relative to monovinyl-substituted 1-pyrazolines indicates participation of both vinyl groups and suggests simultaneous cleavage of the two C-N bonds.
[*] Dr. M. Schneider
lnstitut fur Chemie der Universitat Hohenheim
7000 Stuttgart 70, Emil-Wolff-Strasse 14 (Germany)
i{
ItJ
I
Within the sensitivity of 'H-NMR spectroscopy, low temperature photolysis i s found to produce only (2) and ( 5 ) . Neither
(3) nor 4-vinylcyclopentene ( 0 1 IS observed; nor is ( 6 ) a
product of the thermal reaction. This is reasonable since the
direct formation of (3) and (6) from ( 4 ) would require
rotations leading to the loss of resonance energy of up to
12-14 kcal/mol per allylic bond[51.All (3) produced in the
photochemical and probably also on the thermal decomposition of ( l c ) and ( I t ) is therefore formed ricr Cope rearrangement of initially produced ( 5 ) .
The low temperature photolysis of (Zc) and ( I t ) has
become a convenient source of ( 5 ) l h 1 and permits kinetic
study of the Cope rearrangement ( 5 ) + (3) by integration
of the NMR resonances of (3) at 6=2.23 and 2.85ppm (cf.
Table 2).
Table 2. Kinetic data of the rearrangement ( 5 ) + ( 3 ) .
T["CI
10' h [ s -
'1
7.2
4.3
10.2
6.1
AC3=20.7 k c a l m o l : AH'=17.812
12.0
6.8
14.2
9.0
17.2
13.5
1x6
14.5
kcal;mol; AS*= - 8 . 5 k 4 e , u .
[**I
Presented in part at "Recent Developments in Physical Organic Chemistry" at Lii-ge (Belgium) (March 1975) and the Chemiedorententagung 1975
a t Ddweldorf (April 1975).
We, thank Dr. P. F i s d w , Univcrsitit Stuttgart. for assisting with N M R
work. and t h e Deutsche Forschungsgemeinschaft for financial support.
The data are to be considered as tentative, since the conveniently observed temperature range is quite narrow, leading
to uncertainties in AH* and AS*. The AG* values thus
707
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monoxide, homotropones, hexamethyl, trish, carbon, dimethylcyclopropen
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