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Mn2(CO)10CH2N2 A Stable Organometallic Derivative of Diazomethane.

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because they do not exist in a rotationally symmetrical conformation (analogous to ( I ) ) for steric reasons but instead, at
the expense of a transannular H/H interaction, most probably
in a conformation having a symmetry plane (corresponding
to (2)).
m)]. On heating to 60°C for half an hour the proportion
of (2) increases but irreversible reactions then also compete.
The possibility of virtually unhindered attack at the double
bond endows ( 4 ) with considerable potential as a synthetic
Since only heterocyclic syn-bishomobenzene derivatives
have hitherto been synthesized[', 31 we attempted to prepare the
dicarboxylic ester (2) from cyclooctatetraenedilithium ( 5 ) ,
carbon dioxide, and diazomethane. T o our surprise we isolated
29 % of ( 4 ) and 6 % of (7) as reaction products.
This result contradicts earlier reports that ( 5 ) reacts with
C 0 2 to give either 80% of (6)[41 or (after the action of
CH2N2)50 to 65 % of (7) together with 0 to 3 % of @)I5]:
syn-tricyclo[5.1 .0.02s4]oct-5-ene-3,8-dicurbox~late
A solution of (5)r4,51, prepared from cyclooctatetraene
(1 5.5 g) and lithium (2.1 g) in diethyl ether/tetrahydrofuran
(9: 1, 500ml) under argon, is poured on to dry ice (ca. 500gj
in a stream of inert gas (danger of ignition!). After addition
of ether (100mI) and (at room temperature) water (200ml)
and conc. HCI (60ml) the mixture is filtered under suction
from 7.0g of precipitate (yielding 1.Og of (7) with CH2N2j.
Treatment with a further portion of conc. HCI (40ml) affords
19.9 g of residue after extraction with ether (21) and evaporation, of which 11.4g dissolve in 250ml of ether at 25°C (affording 0.8 g of (7) and 1.O g of ( 4 ) on esterification and chromatography). On treatment with diazomethane in methanol/ether
and chromatography over SOz with CH2CI2 the remainder
gives 8.7g of ( 4 ) , which is recrystallized from C H 3 0 H at
- 20°C.
Received: December 4. t975 [ Z 375 IE]
German version: Angew. Chem. 88. 185 (1976)
CAS Registry numbers:
( l ) , 3725-30-2; ( 2 ) , 58343-25-2: ( 3 ) , 3786-99-0:
14), 58383-69-0: ( S j , 34728-91-1 ; 16j. 58343-26-3;
( 7 ) . 38127-08-1 ; (8). 35242-13-8; ( 9 ) . 58383-70-3
_ _ ___
R = C02CH,
The differing findings still require an explanation. The structure of ( 4 ) (C12H1404[61rm.p. 87--89°C) follows unequivocally from a comparison with the anti isomer (a)['], its 'HNMR spectrum [CDCI3 : 6= 0.7-1 .0 (2 H", m), i .6-2.05 (2 Hb,
m), 2.05-2.4 (2Ha, m), 3.73 (6H, s), 6.05-6.3ppm (2Hd,
m); coupling between Hb and Hd], and epoxidization to give
(9)["] [m.p. 185--187°C; NMR (CDCI3): 6 = 1.35-1.6 (2W,
m), 1.7-2.25 (4WSb,m), 3.3-3.35 (2Hd, m), 3.75ppm (6H,
s)]. For steric reasons and because of the relatively narrow
NMR signal of the epoxide ring protons the synlanti structure
is assigned to (9). It is formed from ( 4 ) and peracetic acid
in methylene chloride in the presence of solid disodium hydrogen phosphate (24 h stirring at ca. 25°C; 84 % yield after
crystallization from benzene).
R = CO,CH,
The crystals of the readily accessible syn-bishomobenzene
derivative ( 4 ) can be stored for several days at room temperature. In solution it equilibrates within a few hours with ca.
20% of (2) at room temperature [NMR (CDCI3): 6=3.76
(6H, s), 4 . 1 5 4 . 4 (2H, br. t, J=5.1 Hz), 5.7-6.1 ppm (6H,
W R. Roth and B. Pekzer, Angew. Chem. 76, 378 (1964); Angew. Chem.
Int. Ed. Engl. 3 , 440 (1964); Justus Liebigs Ann. Chem. 685, 56 (1965):
J . Zirner and S. Winsteiii, Proc. Chem. Soc. London 1964, 235.
H . Prinzbarh, M . Breuningrr. B. Gullmkamp, R. Schwesiiiger, and D.
Hunklrr. Angew. Chem. 87, 350 (1975): Angew. Chem. Int. Ed. Engl.
14, 348 (1975).
E. Voqel, H . J . Altenhuch, and D. C r m e r . Angew. Chem. 84. 983 (1972);
Angew. Chem. Int. Ed. Engl. 11, 935 (1972); H . J . Alteribach and E.
Kigrl. ihid. 84, 985 (1972) and I f , 937 (1972), respectively; E. Vogel,
E . Schmidbuurr, and H . J . Alrenback, ihid. 86. 818 (1974) and 13, 736
(1974); D. Sfirsche, M . Brecmiiiger, and H . Prinzhoch, Helv. Chim. Acta
Sj, 2359 (1972).
W Ruppr, 0. SchJichtimq, K . Kluger, and 7: Toepel, Justus Liebigs Ann.
Chem. 560, I (1948).
?: S . Cuiirrrll, Tetrahedron Lett. 1Y68, 5635: J. Am. Chem. Soc. Y2,
5480 (1970).
All new compounds gave correct values on elemental analysis. NMR
assignments are confirmed by selectively decoupled '3CC-NMRspectra
[ ( 4 ) (CDC13):& = I 7 3 2 (s), 125.1 (d), 51.9 (4). 28.4 (d). 19.5 (d), 16.9ppm
D.L. Dalrrmple and S. P. B. Tudor, J. Am. Chem. Soc. Y3, 7098 (1971).
Mn,(CO),,CH,N,, A Stable Organometallic Derivative of Diazomethane['I
By W A . Herrmann, M . L. Ziegler, K . Weidenhammer, H .
Biersack, K . K . Mayer, and R. D. Minard[*]
Intermediate diazomethane- and carbene complexes are responsible for the variety of reactions diazomethane exhibits
in the presence of catalytically active metal compounds121.
It was recently shown that carbene, CH2, could be transferred
[*] Dr. W. A. Herrmann ['J. H. BiersBck. Dr. K. K. Mayer, and Dr.
R D. Minard [*"I
Chemischea lnstitut der Universitiit
Universitatsstrasse 31, 8400 Regensburg 1 (Germany)
Prof. Dr. M. L. Ziegler and Dipl.-Chem. K . Weidenhammer
Anorganisch-chemisches lnstitut der Universitat
Im Neuenheimer Feld 270, 6900 Heidelberg 2 (Germany)
Present address: Department of Chemistry, The Pennsylvania State
University, State College, Pa. 16802 (USA).
['I Author to whom correspondence should be addressed.
A i i g m , . Chem. Inr. Ed. Engl.
/ Vol. 15
(1976) No. 3
from its diazo precursor to organometallic compounds[31.We
now report the introduction of unfragmented diazomethane,
CH2N2,into a manganese complex with an unusual structure.
Reaction of pentacarbonyl manganese hydride in tetrahydrofuran at - 85 "C with excess diazomethane and subsequent
column chromatography at room temperature afforded a light
yellow, easily crystallized, air stable and thermally stable (ca.
115 "C dec.) compound[41.From the complete elemental analysis and high resolution mass spectrum it follows that the
diamagnetic compound formed according to
has the empirical formula C1IH2Mn2N2010;
the osmometric
molecular weight determination also confirms the presence
of a binuclear neutral compound (I ). The carbene insertion
product (C0)5MnCH3discovered by Hieber et aLi5]was not
found in the final product under our experimental conditions.
On electron impact ionization of ( I ) in the mass spectrometer (Varian MAT CH 5; PE=70eV; Em=300pA;
TQ=800C;direct inlet T=5O0C) the molecular ion (m/e=432)
successively loses ten CO groups, with the base peak at [M9CO]+ (m/e= 180); further decomposition of Mn2CH2N:
proceeds oia MnCH2N: to MnCH: (m/e=69, rel. int. 52 %).
Besides the Mn2(CO)loCH2N2 series a decay series of
mononuclear ions starting from (C0)5MnCH2N: (m/e= 237)
is also observed.
Although the mass spectrometric high resolution analysis
of the parent and the fragment ions proved incorporation
of intact diazomethane in the complex molecule, no proton
signals could be detected in the 'H-NMR spectrum. In order
to clarify this dichotomy we carried out a complete three
dimensional X-ray structure analysis of (I )[61. It showed that
diazomethane has, indeed, been introduced as an unfragmented species into a binuclear complex consisting of both
Mn(CO)5-and Mn(C0)4-moieties(Fig. 1). ( 1 ) is part of an
unusual four-membered framework arising from conversion
of a terminal carbonyl group into an acyl function. The bridg-
ing system is coplanar including both hydrogen atoms localized by X-ray analysis.
The IR spectra of ( 1 ) can also be interpreted on the basis
of these structural data: The intense bands at 1644 and
1575cm-' (KBr) are assigned to the ketonic CO and the
N=CH2-groups, respectively.From the nine possible IR active
valence vibrations (7A'+ 2A") of the terminal CO groups
postulated by a vibration analysis for a molecule of symmetry
C,, eight are observed as separate bands (2122w, 2086m,
2062 vw, 2036 vs, 2027 vs, 2005 s-vs, 1988 vs, and 1966cm- vs;
The synthesis of ( 1 ) is the first example of coordination
of diazomethane to metal via both nitrogen atoms. Our results
demonstrate that the basicity of the diazo carbon atom is
not necessarily the key function for the special reactivity of
diazomethane toward metal compounds. The initial reactions
can also occur exclusively at the diazo group if the metal
complex fulfills chemical and structural requirements.
Received: December 22, 1975 [Z 380 iE]
German version: Angew. Chem. 88. 191 (1976)
CAS Registry numbers:
Mn(CO),H, 16972-33-1 ; CH,N,, 334-88-3; Mn,(CO),,CH,N,,
Complex Chemistry of Reactive Organic Compounds, Part ll.-Part
10: W A. Herrmann, Chem. Ber. 108, 3412 (1975).
M . F. Lappert and J . S . Poland, Adv. Organometal. Chem. 9, 397 (1970);
P. W Jolly and G. Wilke, The Organic Chemistry of Nickel, Vol. I,
Academic Press, New York 1974.
W A . Herrmann, 5. Reiter, and H. Biwsuck, 1. Organometal. Chem.
97, 245 (1975).
in addition, three other new complexes could be isolated and identified
by elemental analyses, spectroscopic investigations. and X-ray analyses.
W A . Herrmann, M . L. Ziegler, and K . Weidenhammer, to be published.
W Hieber and G . Wuynrr, Z. Naturforsch. 126, 478 (1957); Justus Liebigs
Ann. Chem. 618, 24 (1958); DBP 1053504 (1959), BASF; Chem. Abstr.
5 5 , 9282 (1961).
[6] The compound crystallizes from methylene chloride/acetone (1 : 1 :
-35°C) mdnoclinically in the space group C:,-P2,/c wlth a=1052.6(3).
b=1062.0(2),c=1429.5(7)pm, p=93.62(5)", 2 = 4 . 2932 independent nonzero reflections were recorded with an automatic Siemens singlc crystal
diffractometer (AED) and corrected in the usual manner: R =4.6 %.
Cyclopropanation of [2.2]Paracyclophanes['
By Klaus Menke and Henning Hopf ['I
As X-ray structure analysis showsi2],in [2.2]paracyclophane1,9-diene, and presumably also in the parent hydrocarbon
[2.2]paracyclophane ( 1 )L31, the aromatic hydrogen atoms do
not lie in the plane of the benzene rings but are bent toward
the hydrogens of the opposite benzene ring. This unusual
structural feature is ascribed to a partial rehybridization
of the benzene carbon atoms (sp2+sp3). A consequence is
that part of the x-electron density is shifted to the outside
faces of the molecule and the energetically unfavorable
transannular penetration of the x-systems of the two benzene
rings pressed face-to-face is reducedr3].As a result of this
increased external electron density, ( I ) and its derivatives
ought to readily undergo addition reactions with divalent
species-carbenes, nitrenes, and possibly oxygen in the case of
epoxidation. The cyclopropanation of tetramethyl [2.2]paracyclophane-4,5,12,13-tetracarboxylate
(2) described here confirms this assumption.
( 2 ) reacts already at 10-15°C with a 40-fold excess of
in dichloromethane in the presence of cataly241
Fig. I . ORTEP plot of the molecular structure of ( 1 ). The thermal ellipsoids
have 50 % probability; all atoms are drawn in proper dimensions except
for hydrogen (bond lengths in pm).
Anyew. Chem. I n t . E d . Engl.
1 Vol. 15 (1976) No. 3
Dipl.-Chem. K. Menke and Prof. Dr. H. Hopf
Institut f i r organische Chemie der Universitat
Richard-Willstitter-Allee 2, 7500 Karlsruhe 1 (Germany)
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organometallic, mn2, diazomethane, 10ch2n2, stable, derivatives
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