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Olefin-Insertion into Cobalt(d8) ComplexesЧStructure of Ethylene(phenyl)tris(trimethylphosphane)cobalt.

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methylene-1,4-pentadiene (1.2)") [IP,JTJ = 8.80, IP2,,(n,) =
9.95 eV] shows that the sequence derived for (10) in Figures 1 and 2 is in very good agreement with that of the structurally related triene (12). All three reference compounds (2),
(lo), and (12) demonstrate that in (la) the circumannular
through-bond conjugation (sequence S > A) dominates over
the transannular through-space interaction (sequence
A > S)"'.
Received: March 18, 1980 [Z 569 IE]
German version: Angew Chem. 92, 833 (1980)
The new olefincobalt complexes were synthesized from
known compounds[4iaccording to eqs. (a) and (b); propene
or cyclopentene can also be used, instead of ethylene.
CAS Registry numbers:
(2), 74965-17-6;(3). 4756-84-7;(4a). 32426-61-2;(46). 32426-60-1;(Sa), 7496518-7;(Sb), 74985-45-8; (6a), 74965-19-8;(6b), 74985-46-9:(7a). 74965-20-1;
(76). 74985-47-0@a), 74965-21-2;lab), 74985-48-1;(9a). 74965-22-3;(9b),
[ I ] M. Horner. S. Hunrg, J. Am. Chem SOC.99, 6120 (1977), J. Harnrsch, G.
Sreimies, Tetrahedron Lett. 1978,247;S. Mazur. A . H. Schroder. M . Werss, J .
Chem. SOC.Chem. Commun. 1977,262;M. Dagonneau. P. Merzner. J. Vralle,
Tetrahedron Lett. 1973. 3675.
121 P. Hemmersbach, M. Klessinger, P. Bruckmann, J . Am. Chem. Sac. 100, 6344
(1978):J. M. Behan, R. A. W . Johnstone, J. J. Worman, T. P. Fehlner, J. Mol.
Struct. 40. 151 (1977);R. Spajford, J. Barardo. J. Wrobel, M. Vala, J. Am.
Chem. SOC.98,5217,5225 (1976);M . Simonetta, S.Carra, Tetrahedron Lett.
1962. 913:J J. Wormann, E. A. Schmidt, E. S. Olson, R. D. Schultr, Spectrochim. Acta A 32, 1415 (1976).
[31 H.-D. Martin. B. Mayer, Tetrahedron Lett. 1979,2351
141 E. Heilbronner, Isr. J. Chem. 10, 143 (1972);E. Heilbronner, H.-D. Martin,
Helv. Chim. Acta 55. 1490 (1972).
151 J. R. Scheffer, R. A Wostradowski, J. Org. Chem. 37,4317 (1972).
161 J C. Bunzh. A . J . Burak, D. C Frost, Tetrahedron 29, 3735 (1973).
[71 Synthesis of (12): 1.2.3-propanetricarboxylic acid is converted via the trichloride. tris(dimethylamide). and trisfdimethylamine) into the corresponding quaternary ammonium hydroxide, which IS then thermolyzed at 18O"C/
12 torr. Synthesis by ester pyrolysis: W. Bailey, J. Am. Chem. SOC.77, 1133
The reference compounds (10) and (12) also enable a satisfactory construction of the PE spectrum of [4]-radialene according to the LCBO method see
T. Bal/.v. U . Buser, E. Haselbach, Helv. Chim. Acta 61, 38 (1978).
Olefin-Insertion into Cobalt(d*) ComplexesStructure of
By Hans-Friedrich Kfein, Reinhard Hammer, Joachim Gross,
and Ulrich Schubert['l
The formal insertion of olefins into transition metal-hydrogen or -carbon bonds is a cardinal problem of organometallic chemistry and the principal feature of important industrial processes[''.
The diamagnetic ethylenecobalt(1) complexes (4)-(6)
were crystallized from pentane solutions. The complexes
gave correct elemental analyses. The crystals can be stored
under Ar at 20"C, but rapidly decompose on exposure to
(4) forms greenish yellow leaflets, which sublime with decomposition at 35-4O0C/O.1 mbar and are stable up to 95 "C
under 1 bar Ar. The brownish-yellow crystals of (5) sublime
at 60-65 "C/O.l mbar, likewise with decomposition; m.p.
115-117 "C (dec.). (6) was obtained as well-formed orangeyellow crystals, dec. >99 "C.
The dynamic 'H- and 3'P-NMR spectra of (4)-(6) evidence anisochronic "P nuclei (2: l ) for the ground state, and
thus indirectly the cis relationship of anionic ligands and
ethylene. An axial position of the hydride ligand in (4) cannot be deduced from the spectra; the structure (4) was formulated in analogy to the structure of the methyl compound (5).
A comparison of the NMR data of (5) with those of
indicates an axial position for the CH3
ligand, consistent with a theoretical
All three complexes behave differently in solution. On using CH30D for the synthesis of (4) according to eq. (a), IR
spectroscopy reveals a nearIy random distribution of the deuterium over five positions of the product: four sites in ethylene (vCD 2100 cm-l) and one at the cobalt (vcoH 1850
cm- I ) . Solvent-free 1-pentene is catalytically isomerized by
(4) (0.5 mol-%, 20 "C, 48 h) to 2-pentene (cis:trans= 9 :
thus demonstrating u-rn rearrangement in the 18-electron
compound (4) (Scheme 1).
L3C o H ( C H ~ = C H Z )
While the u-T rearrangement (1)*(2), a reversible p-elimination, is relatively well established''', there is only little experimental evidence supporting the practically irreversible
insertion (3)+ (2)f31.
As potential insertion precursors, we have prepared the
three pentacoordinated cobalt(1) complexes (4)-(6), which
contain a Co-H or Co-C bond in the cis position to the
equatorially bound ethylene ligand.
Prof. Dr. H.-F. Klein. Dr. R. Hammer, DipLChem. J. Gross, Dr. U. Schubert
Anorganisch-chemisches Institut der Technischen Universitat Miinchen
Lichtenbergstr. 4, D-8046 Garching (Germany)
[**I This work was supported by the Deutsche Forschungsgemernschaft and the
Fonds der Chemischen Industrie.
Angew Chem Inl. Ed. Engl 19 (1980) No 10
L3C OR(CH2=C H,)
=+L3C oH(CHz=CHR)
(518 ( 6 )
Scheme 1 . L = PMe,; R = CH,, CoH,
In contrast, a thermal isomerizatioa into the complex of
type (4) (Scheme 1) in the sense of an insertion-p-elimination reaction ~equence"~
is not observed in the case of (5); 1pentene is not isomerized by (5).
16) + Co(C,H4)(PMe3)3+ 1/2C6H,-C6H,
0 Verlag Chemie. GmbH, 6940 Weinheim, 1980
S 02.50/0
On warming, ethylene-saturated solutions of (6) (e.8. in toluene, 1 bar C,H,, 50 "C, 8 h) furnish biphenyl and paramagnetic ethylenetris(trimethylphosphane)cobalt(o) (7)l4"l in
quantitative yield. Styrene and hydridocobalt complexes, as
by-products of an insertion reaction (Scheme l), were not detected.
Ed. Engl. 16, 299 (1977); d ) cf. also H.-F Klein, ibid. 92, 362 (1980) and I Y ,
362 ( 1980).
12) a) M. Tsursur. A . Courtney, Adv. Organomet. Chem 16, 241 (1977); b) B.
Gorewil, M. Tmlsui. Adv. Catal. 27, 227 (1978); c) D. L Thorn, R. Hofmann.
J . Am. Chem. Soc. 100. 2079 (1978).
131 E. R. Evil/, R. G. Bergman, J . Am. Chem. Soc. 101, 3973 (1979); K. J. lvin, J.
J. Rooney, C. D. Stewart, M L. H. Green, R Mahtab. J . Chem. SOC.Chem.
Commun. 1978. 604. M. L H. Green. R. Mahtab, J Chem SOC. Dalton
Trans. IY7Y. 262.
[4] a ) H.-F Klein, R. Hammer, J Wenninger. J. Gross in B. Pullman: Catalysis in
Chemistry and Biochemistry. D. Reidel. Amsterdam 1979, p 285; b) H.-F.
Klein, H. H. Karsch, Inorg. Chem. 14. 473 (1975); c) Chem Ber. 108, 944
[5] J. K. Burdetr. Adv. Inorg. Chem. Radiochem. 21, 113 (1978).
[6] R. Hammer, Dissertation, Technische Universitat Miinchen 1977.
171 The expected hydrido(propene)cobaIt complex could previously only be obtained analogously to (4). according to eq. (a) 161. One of the thermolysis
[8] H.-F. Klein, J. Wenninger. U . Schubert. 2 . Naturforsch. B 34. 1391 (1979).
The Nitrile Function of Tetracyanoethylene as
Dienophile in Diels-Alder Reactions[**]
Fig. I . ORTEP diagram of the molecule (6) in the crystal. The hydrogen atoms
219.2(3). Co-P2 221.5(2),
have been omitted for sake of clarity. Co-PI
Co-C(Ph) 199.9(6), Co-C(Eth) 204.0(7), 205.6(7), C-C(Eth)
143(1) pm.
11I .7(2), P2-Co-Eth
110.4(2). C(Ph)-Co-Eth
81 612).
160.26(8), PI-Co-P2
97.91(7). PI-Co-C(Ph)
92.6(2). Eth=center of the C-C bond in the ethylene Iigand. (6)
crystallizes orthorhombically. a= 1342(1), b = 1301(4), c=2423(4) pm; Y=4230
pm'; ~ ( c a l c .=) 1.23 g/cm'; space group Cmca; MoK,,radiation, ( h =71.069 pm.
graphite monochromator): 1800 independent reflections (2" s 2 8 s 50").
R , =0.041. R2=0.046 for I169 structure factors with F , , ~ 3 . 9 2 o ( F ~ ~ ) .
The X-ray structure analysis of (6), however, revealed that
the configuration is favorable for the insertion step, at least
in the solid state (Fig. 1). The complex has crystallographic
C,-symmetry with coplanar arrangement of all C-atoms of
phenyl and ethyl ligands and of the vector of the Co-P2
bond in the mirror plane. Thus, a reaction path is available
which involves minimal rearrangement of the participating
atomic centers. The reason for insertion not taking place lies
either in the unfavorable orbital
or unknown
thermodynamic quantities. The complex (6) is markedly distorted from a trigonal pyramidal coordination (PI and P1*
axial) in the direction of a square pyramidal coordination
with P2 in the axial position. This distortion could be caused
by the strong steric interaction between ethyl- and phenyl-ligand, which results from their coplanarity.
(6): A 0 . 9 0 ~solution (1.62 ml) of LiC6HSin ether is pipetted into a suspension of C O C ~ ( P M ~ (470
~ ) ~mg,
[ ~ ~1.46
I mmol)
in ether (20 ml) at -78 "C under 1 bar ethylene. The stirred
mixture is warmed to 20 " C and stirring continued for a further l h. The volatile components are removed in a vacuum
and the brown residue is extracted twice with 10 ml pentane.
On slowly cooling over dry-ice, orange-yellow crystals of (6)
separate out; yield 310 mg (55%).
Received. February 13. 1980 [ Z 570 IE]
German version: Angew. Chem. 92, 835 (1980)
CAS Registry numbers:
(4). 68830-26-2; (5). 73557-04-7; (6). 74965-07-41; CoCI(PMe3)l 53432-06-7
[ I ] a) G. Henrici-Olive, S Olive: Coordination and Catalysis. Verlag Chemie,
Weinheim 1977, p. 122f.: b) J. L. Dauidson, Inorg. React. Mech. 5. 346
(1977); c) F. Calderazzo. Angew. Chem. 89, 305 (1977). Angew. Chem. Int.
0 Verlag Chemie. GmbH, 6940 Weinheim. 1980
By Klaus Burger and Herbert Goth"1
Dedicated to Professor Roy Huisgen on the occasion of
his 60th birthday
Cycloaddition reactions to tetracyanoethylene (TCNE)
proceed with high site selectivity at the CC double bondl'l.
Examples of [3 + 21-cycloaddition reactions, in which one of
the nitrile groups functions as reaction partner, are rare''],
and no examples of Diels-Alder reactions have, to our
knowledge, been reported[31.
We have found that the l-thia-3-aza-1,3-pentadienes
accessible by electrocyclic ring opening from 2,2-bis(trifluoromethyl)-2H-1,3-thiazete derivatives ( l ) , react with
TCNE already at 120 " C (bath temperature). A [l : 11-adduct
can be isolated from the product mixture in 50--60% yield
(Table 1).
Table 1. Yields, melting points, and IR data of compounds (3).
2233, 1658, 1578
2232, 1657, 1607
2233, 1660. 1642, 1584
The color of the products, an IR absorption at 1655-1660
crn-', and a singlet representing six fluorine atoms at
6 = -2.1 in the "F-NMR spectrum''' indicate reaction of
one of the nitrile functions. The mass spectrometric fragmentation pattern, which reveals the electron-impact induced retro-Diels-Alder processed6] [M - RCN]g and [M - TCNEIE
of comparable intensity and intense lines for the fragmentation ions [(CN)2C=-C(CN)C=S]@ and [RC=S]@, confirms
the constitution of a 4H-1,3,5-thiadiazine (3). The possible
conversion into a symmetric [2: 11-adduct on subsequent
heating in the presence of (1) is also consistent with structure
(3). The [2: 11-adducts are present in minor amounts in the
crude products of the reaction of ( l j with TCNE, even on using twice the amount of (1). Compounds of type (2) with oxygen instead of sulfur do not react with TCNE under comparable reaction conditions.
[*] Prof. Dr. K. Burger, Dr. H. Goth
Organisch-chemisches lnstitut der Technischen Universltal Miinchen
Lichtenbergstrasse 4. D-8046 Garching (Germany)
[**I This work was supported by the Deutsche Forschungsgemeinschaft.
S 02.50/0
Angew. Chem. In[. Ed. Engl. I9 (1980) No. 10
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complexesчstructure, ethylene, insertion, phenyl, olefin, trimethylphosphine, trish, cobalt
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