close

Вход

Забыли?

вход по аккаунту

?

Azo Coupling of -Diazo Carbonyl Compounds with N-(1-Cyclopentenyl)amines.

код для вставкиСкачать
H
HO~C-C-NCN
c = o r
oso
HOMO
H
HOzC-C-N=N
- 9.2 eV
LUMO
+ ]],,
1.0 eV
c=0,29
4
-+
8.9
0.63
0.3
0.44
HzC-C-COzH
H
H
H 0 2C - C -N=N
c = 0.68
\
0.67
HOMO
- 9.2 eV
4
0.20
j
0.31
LUMO
0.40
HO~C-C-CHZ
H
H
HOzC-C-N=N
+
H2N-C-C(CH3),
H
Scheme 1.
+ 2.8
LUMO
0:44
- 10.7
HOMO
LUMO
c = 0 2 1 9 r 2
12.0
6.55
4
1
0.55
H~N-C-C(CH,)~
H
t
+ 1.0
8,7av
.)
- 7.7
HOMO
For diazoacetic acid + acrylic acid the two HOMO-LUMO
interactions determine the opposite directions of addition;
owing to the small energy difference HOMO(diazoacetic acid)LUMO(acry1icacid) prevails, i. e. the 3,5-pyrazolinedicarboxylic ester is formed. With diazoacetic acid + N-isobutenylamine
two HOMO-LUMO interactions cooperate in formation of
the 4-amino compound.
Received: February 6, 1979 [Z 174a IE]
German version: Angew. Chem. 91, 346 (1979)
CAS Registry numbers:
(21, R =CH3, 32286-98-9; (21, R O ~ C = P - N O ~ C ~ H , C 69668-68-4;
O,
(41,
69668-69-5; (51, 69668-70-8; ( 7 ) , 25016-17-5; ( 8 ) , 2403-57-8; ( l o ) , 6966871-9; ( I I j, 69668-72-0; (12), 21603-19-0; ( 1 3 1 , 60858-33-5; methyl diazoacetate, 6832-16-2; N-(I -cyclohexenyl)pyrrolidine, 1125-99-1; p-nitrodiazoacetophenone, 4203-31-0; dimethyl diazomalonate, 6773-29-1 ; trans-N-(1propenyl)pyrrolidine, 13044-42-3; cis-N-(I -propenyl)pyrrolidine, 13098-67-4
[l] F. Piozzi, A . Umani-Ronchi, L. Merlini, Gazz. Chim. Ital. 95, 814 (1965).
[2] E. Wenkert, C . A . McPherson, J. Am. Chem. SOC.94,8084 (1972), described
the oily impure ethyl ester of type (10).
[3] A . f.Day, R . N . inwood, J. Chem. SOC.C1969, 1066.
[4] J . van Alphen, Rec. Trav. Chim. Pays-Bas 62, 485, 491 (1943); R . Hiirtel,
J . Rirdl. H . Martin, K . Franke, Chem. Ber. 93, 1425, 1433 (1960).
[5] E. Buckner, Ber. Dtsch. Chem. Ges. 21, 2637 (1888); 23, 701 (1890).
[6] R . 4 . Firestone, J. Org. Chem. 37, 2181 (1972).
[7] We are grateful to Prof. R . Susrmann, Essen, for the CNDOj2 calculations.
[8] The orbital energies were estimated from experimental data; H:U. Reissig, Dissertation, Universitat Miinchen 1978, Section 8.6.
Azo Coupling of a-Diazo Carbonyl Compounds with
N-(1-Cyclopenteny1)amines
By Rorf Huisgen, Werner Bihlmaier, and Hans-Cilrich Reissig"]
Dedicated to Professor Horst Pommer on the occasion of his
60th birthday
Combination of methyl diazoacetate with N-(I-cyclopenteny1)morpholine ( I ) (1 week, 20°C) gave a yellow crystalline
1 : 1 adduct, uiz. enamine hydrazone ( 4 ) , in 51 % yield ['HNMR (CDC13):6=4.2 (s, br. NH, vanishes with DzO), 5.4 (t,
J=2.2Hz, vinylic H, disappears with D30@),3.95 (s, CH2
of side chain) 3.70 (s, OCH,)]. Compound ( 4 ) was accompanied by only 1-2% of the cycloadduct ( 3 ) ; ( 4 ) could
not be converted into (3). The I ,3-dipolar cycloaddition[']
which dominates reaction of N-(1-cyclohexenyl)dialkylamines
is suppressed by an azo coupling-presumably via the zwitterion ( 2 ) .
The enamine system of ( 4 ) added 4-nitrophenyl azide to
give a triazoline (92% yield), which still contains the NH
p] Prof. R. Huisgen, DipLChem.
W. Bihlmaier, Dr. H.-U. Reissig
Institut fur Organische Chemie der Universitat
Karlstrasse 23, D-8000 Miinchen 2 (Germany)
Angew. Chem.
lilt.
group (F=3290 cm-'). Mild hydrolysis on silica gel transformed ( 4 ) into an 0x0 hydrazone with intramolecular NH
bridge.
( 5 ) ) R = COzCH3
Dimethyl diazomalonate reacted with ( 1 ) even at - 30°C
in ether; an orange-yellow 65:35 mixture of crystalline enamine hydrazones syn-(5) and anti-(5), respectively, (66%
yield) could be precipitated with hexane. According to the
'H- and 13C-NMR spectra, the ester groups are equivalent
['H-NMR (nitrobenzene): syn-(5) and anti-(5), respectively,
6=5.70 and 5.55 (NH), 5.12 and 4.98 (malonic ester H), 5.33
(vinylic H); all these protons exchange with D,O@]. The UV
maximum at 355 nm (log E = 2.6, dioxane) reflects the conjugation of the enamine and the hydrazone system.
Are zwitterions of type (2) likely candidates as primary
products? The zwitterion (7) obtained from the more nucleophilic species N-( 1-cyclopentenyl)pyrrolidine (6) and diazomalonic ester is isolable. (7) was formed in ether or cyclohexane at 25°C in 93 % yield; brick-red needles m. p. 89°C (dec.),
which can be stored at -30°C; IR (KBr): V"C=N+ 1694,
\;C=O 1650cm-'. The color is due to intramolecular charge
transfer interaction; i
,
,
,
(CHC13) 477 nm (loge=4.3). The
weak diazomalonate absorption at 2135 cm- (in CHCl3) indicated a dissociation equilibrium of (7) with the reactants.
Distillation of (7) at S0-90°C/0.001 torr proceeded via retrocleavage and recombination; (6) was trapped by triazoline
formation with 4-nitrophenyl azide placed in the receiver.
'
The IR solution spectra and the ' H- and ,C-NMR spectra
of (7) also indicate equilibration with the syn,anti isomeric
enamine hydrazones ( 8 ) and ( 9 ) . Their structural resemblance
to the stereoisomers of ( 5 ) permitted assignment of the NMR
signals to the zwitterion (7). In pyridine at 3 2 T , 43 % of
(7) was present with 57 % of ( 8 ) + ( 9 ) (in the ratio 1.4: 1);
the equilibrium is temperature dependent [in CDC13: 40%
of (7) at -49"C, and 15 % of (7) at +28"C]. The occurrence
Ed. Engl. 18 (1979) No. 4
0 Verlag Chemre, GmbH, 6940 Wernkerm, 1979
331
0570-0833/79i0404-033S $ 02 5010
of two ester methyl signals (6=3.70 and 3.75 in pyridine,
3.85 and 3.88 in CDCI3) demonstrates the limited rate of
equilibration['!
Yet another equilibrium was indicated by the transformation
of (7) in acetonitrile into orange crystals of C18Hz8N4(24 %
yield), probably the azo-bis(enamine) (1 2). We suspect a dissociation of ( 7 ) , with prototropic shift, into the anion (10)
and the cation ( l l ) , which combines with ( 6 ) , formed in
the other dissociative equilibrium, to give (12). Dimethyl
(7) 2
+
HzC(COzCH3)a
L
(12)
fI1)
malonate could be detected. Such azo-bis(enamines) have been
observed on reaction of dimesyl- and bis(phenylsulfony1)diazomethane with substituted a-m~rpholinostyrenes[~~.
Azo coupling of m-diazo carbonyl compounds with N-( 1-cyclopenteny1)amines can be described in terms of M O perturbation theory by combination of the H O M O and LUMO centers
with the greatest atomic orbital coefficients (cf. ['I ) . According
to the 13C-NMR spectra, C-4 has a somewhat greater charge
density in cyclopentenylamines than in cyclohexenylamines.
It could not be predicted, however, that this would lead to
such drastic differences in reactions with a-diazo carbonyl
compounds: azo coupling in the case of N-(I-cyclopenteny1)and 1,3-dipolar cycloaddition with N-(1 -cyclohexenyl)dialkyIamines.
Mo:'(OzCCH3)4
+ 8 HX + [Mo:IIXgHI3- + 3 H + + 4 CHsCOzH
(1)
This reaction appears to be quantitative when carried out
(a) at temperatures of 60°C and above, and (b) with exclusion
of 02.It had earlierl4' been shown that at 0°C a simple
metathesis takes place according to:
M O Y ( O ~ C C H+~8) HX
~ --* [Mo:IXS]~-+ 4 H
+
+ 4 CHjCOzH
(2)
Reaction (1) constitutes the first unambiguous recognition
of oxidative addition to a well-defined metal-metal multiple
bond.
The [ M O ~ C I ~ H ]anions
~ - have since been shown to have
interesting chemical properties[51;however, their characterization remained incomplete in two respects: Direct structural
evidence for the bridging hydrogen atom was lacking, and
the conformation of the anion, when not constrained to occupy,
in a disordered fashion, a position of D3h symmetry, was
unknown.
We report here experimental results that supply the above
information. We have found that by modifying the reaction
conditions and using cations other than those of the alkali
metals, a great variety of well-crystallized salts of the
[ M O Z X ~ H ] ~anions
can be easily prepared. One of these
new salts, the pyridinium salt [C5NH6]3[Mo2ClSH], has been
studied by X-ray crystallography and a complete structural
characterization of the anion (including the location of the
hydrogen atom) was achieved for the first time.
Received: February 6, 1979 [ Z 174b IE]
German version: Angew. Chem. 91. 147 (1979)
CAS Registry numbers:
(1 ). 936-52-7; ( 3 ) , 69631-56-7; r 4 ) , 69631-57-8; s j n - ( S ) , 69631-58-9;
anti-(5), 69631-59-0; (6), 7148-07-4; ( 7 ) , 69631-60-3; ( 8 ) , 69631-61-4; (9),
69631-62-5; ( 1 2 ) , 69631-63-6; methyl diazoacetate, 6832-16-2; dimethyl
diazomalonate, 6773-29-1
[l] R . Huisgen, H.-U. Reissig, Angew. Chem. 91. 346 (1979); Angew. Chem.
Int. Ed. Engl. 18, 330 (1979).
[Z] The rate phenomena i n the H, D exchange are informative; H.-Li. Reissig,
Dissertation, Universitat Miinchen 1978, pp. 35-49.
[3] U . Schdllkopj; E. Wiskatt, K . Riedel, Justus Liebigs Ann. Chem. 1975,
387.
Oxidative Addition to a Quadruple Bond. The Complete
X-ray Structure of [Mo2ClsHl3- [**I
By Aoi Bin0 and F. Albert Cotton"]
The preparation of the [ M O ~ C I ~ H ]anion
~ - was first described about ten years ago['] although the presence of the
hydrogen atom was not then recognized. A few years later
the bromo analog, [ M O ~ B ~ ~ Hwas
] ~ - reportedrz1. In
1976 the coordinated hydrogen atom was demonstrated by
a combination of chemical observations, isotopic labeling
experiments and infrared spectra[3! The chemical process by
which these ions are obtained was thus shown to be represented
by eq. (1):
[*] Dr. A. Bino, Prof. Dr. F. A. Cotton
Department of Chemistry
Texas A & M University
College Station, Texas 77843 (USA)
[**I This work was supported by the Robert 4.Welch Foundation under
Grant No. A-494.
332
Fig. 1. The structure of the [ C I ~ M O ( ~ - C ~ ) ~ ( ~ - H ) M
ionO C
asI it~ ]occurs
~~
in [C5NH6]3[Mo2ClsH]. Atoms are represented by their ellipsoids (sphere
for H) of thermal vibration at the 50 % probability level.
The pyridinium salt crystallizes in the space group PT with
Z = 2; the anion has no crystallographically imposed symmetry
(Fig. 1). After a structural model omitting hydrogen atoms
had been refined to convergence a difference electron density
map revealed peaks corresponding to hydrogen atoms, one
of which was in a bridging position in the anion. Hydrogen
atoms for the three independent [C5NH6]+ cations were
placed at calculated positions and not refined, while the H
atom in the anion was refined isotropically and the other
atoms were all refined anisotropically. Using 2786 reflections
with I > 3 o(I) and 257 variables final discrepancy indices
of R 1= 0.026, R2 =0.040 and a goodness-of-fit parameter equal
to 1.008 were obtained.
It is clear that in the previous structures the fact that the
[Mo2X8H]'- anions were constrained to disordered occupation of sites of am2 (D3h)symmetry obscured important details
of their structure. The virtual symmetry of the [ M o z C I ~ H ] ~ anion is mm (Czv),where the mirror planes intersect at the
p-H atom; one contains the Mo atoms and the other the
p-Cl atoms. The terminal atoms trans to p-H have a mean
Mo-CI bond distance (Table 1) significantly longer (0.10 A)
0 Vrrlag Chemre, GmbH, 6940 Weinhelm, 1979
0 Vrrlag Chemre, GmbH, 6940 Weinhelm, 1979
0570-0833179 0404-03,1 '$ 0 2 5 0 / 0
0570-0833179 0404-0332 $ 025010
Документ
Категория
Без категории
Просмотров
2
Размер файла
245 Кб
Теги
carbonyl, azo, compounds, couplings, diaz, amines, cyclopentenes
1/--страниц
Пожаловаться на содержимое документа