3-Ferrocenyl-1-methyl- and 1-ferrocenyl-3-methylcyclopropenes

Article abstract of DOI:10.1016/j.jorganchem.2005.09.016

Dehydrobromination of isomeric 3-bromo-1-ferrocenyl-2-methylcyclopropanes afforded 3-ferrocenyl-1-methyl- and 1-ferrocenyl-3-methylcyclopropenes. These undergo smooth opening of the three-membered ring to give 1- and 2-ferrocenylbuta-1,3-dienes and 1- and

Full text of DOI:10.1016/j.jorganchem.2005.09.016

Journal of Organometallic Chemistry 691 (2006) 507–513
www.elsevier.com/locate/jorganchem
3-Ferrocenyl-1-methyl- and 1-ferrocenyl-3-methylcyclopropenes
a
a,
b
c
*
´
´
Elena I. Klimova , Tatiana Klimova , Leon V. Bakinovsky , Marcos Martınez Garcıa
a
Universidad Nacional Auto´noma de Me´xico, Facultad de Quı´mica, Cd. Universitaria, Coyoaca´n, C.P. 04510 Me´xico, D.F., Me´xico
N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 117913 Moscow, Russian Federation
b
c
Universidad Nacional Auto´noma de Me´xico, Instituto de Quı´mica, Cd. Universitaria, Coyoaca´n, C.P. 04510 Me´xico, D.F., Me´xico
Received 9 September 2005; accepted 12 September 2005
Available online 17 October 2005
Abstract
Dehydrobromination of isomeric 3-bromo-1-ferrocenyl-2-methylcyclopropanes afforded 3-ferrocenyl-1-methyl- and 1-ferrocenyl-3-
methylcyclopropenes. These undergo smooth opening of the three-membered ring to give 1- and 2-ferrocenylbuta-1,3-dienes and
1- and 2-methyl-1H-cyclopentaferrocenes; with 1,3-diphenylisobenzofuran they give the classical Diels–Alder adducts.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: Cyclopropene; Cyclopropane; Intramolecular transformations; Opening of the three-membered ring; Ferrocene
1. Introduction
Thus, the small ring in the cyclopropenes 1a,b undergoes
smooth opening on heating with the formation of carbe-
noid intermediates 2a,b [1–3], which then recyclize with
involvement of only the aryl fragment, the ferrocenyl sub-
stituent remaining unaffected (see Scheme 1).
Unlike 3-arylcyclopropenes 1a,b, ring-opening of the
small ring in 3-alkyl analogs 3a,b [3,6–8] results in predom-
inant formation of ferrocenyl-substituted 1,3-dienes (4a–c)
and 3-alkyl-1H-cyclopentaferrocenes (5a–c) as the minor
products (Scheme 2).
Little information concerning the chemistry of ferroce-
nylcyclopropenes with ferrocenyl group as the only sub-
stituent in positions 1 or 3 of the small ring is
available. To date, only the preparation of 1-ferrocenyl-
cyclopropene (6) in an attempt at synthesizing 3-ferroce-
nylcyclopropene is described [10] together with some of
its chemical properties (cycloaddition and protonation
reactions) (Scheme 3).
The effect of the ferrocenyl substituents in small rings is
rather well pronounced and their influence is often highly
selective, therefore, it was of interest to reveal features of
the electronic interaction of the ferrocenyl group with the
small ring, which is attractive from both the theoretical
point of view and in connection with a search for selective
reactions of cyclopropenes and cyclopropanes.
3-Aryl- and 3-alkyl-3-ferrocenylcyclopropenes have
been the subject of studies in recent years [1–8]. Character-
istic features of intramolecular transformations of 3,
3-disubstituted cyclopropenes have been established exper-
imentally, they were shown to depend on mutual influence
of the ferrocenyl and cyclopropene fragments. The geome-
try of the small ring, viz., the C@C and C–C bond lengths
and the values of the bond angles at C(1), C(2), and C(3),
as well as spatial orientation of the substituents at position
3 were established by X-ray diffraction analysis. The ferr-
ocenyl substituent always occupied the ÔbisectorÕ position
relative to the plane of the three-membered ring, other sub-
stituents being in Ônon-bisectorÕ positions.
In 3-aryl-3-ferrocenylcyclopropenes [1,2,4,5] with these
conformations 1a,b, the MO of the ethylene and arene
fragments interact through space as in the case of 3-alkyl-
3-phenylcyclopropenes [9], which seems to determine stereo-
selectivities of the intramolecular transformations of
3-arylcyclopropenes (Scheme 1).
*
Corresponding author. Tel./fax: +52 55 56225371.
E-mail address: klimova@servidor.unam.mx (T. Klimova).
0022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.09.016

508
E.I. Klimova et al. / Journal of Organometallic Chemistry 691 (2006) 507–513
R
Fc
Fc
H
R
R
R
R
Fe
R
Fe
Fc =
2 a,b
1 a,b
CH CH CH CH
R = H (a); R =
(b)
Scheme 1.
R
R
H
C
H
R
CH
C
Fc
R
H
R
CH
H
C
C
C
R
C
C
H
Fe
Fc
3a-c
Fc
R
R
R
C
C
CH
CH2
Fe
R
4a-c
(c)
(CH2)3
R= H (a); R= CH3 (b); R,R=
5a-c
Scheme 2.
tBuOK
DMSO
HBF4
H
BF4
Br
Fc
Fc
Fc
6
Scheme 3.
2. Results and discussion
the starting material for the preparation of compounds 7
and 8. This was synthesized in Scheme 4.
In continuation of our studies in the area of ferrocenyl-
cyclopropanes, we synthesized 3-ferrocenyl-1-methyl- and
1-ferrocenyl-3-methylcyclopropenes (7 and 8, respectively)
and studied some of their chemical properties. trans-1,1-
Dibromo-2-ferrocenyl-3-methylcyclopropane (9) served as
Acylation of ferrocene (!10), reduction to (1-hydroxy-
propyl)ferrocene (11), and dehydration (! 12) occurred
1
smoothly in 65–75% yields. According to H NMR spec-
troscopic data, 1-ferrocenylpropene (12) was obtained as
a ca. 3:1 mixture of trans- and cis-isomers.
EtCOCl
POCl3
1. LiAlH4
2. H2O
,
N
Fc CH Et
Fc COEt
Fe
AlCl3
OH
10
11
Fe
Fc =
Br
Br
H
H
Fc
CBr2
C
C
Fc
H
CH3
H
CH3
12a (trans)
12b (cis)
9
Scheme 4.

E.I. Klimova et al. / Journal of Organometallic Chemistry 691 (2006) 507–513
509
Dibromocyclopropanation of the alkene 12 occurred
stereoselectively: dibromocyclopropane (9) was isolated as
a single trans isomer (JH(2),H(3) = 8.1 Hz [11,12]), in 75%
yield. This compound represents orange powder; it decom-
poses on heating but can be stored unchanged in a sealed
tube at 20 ꢁC.
The dibromide 9 was reduced with a mixture of EtMgCl
and Ti(OiPr)4 as described [13] to give 1-bromo-2-ferroce-
nyl-3-methylcyclopropane (13) as a ca. 1:1 mixture of two
isomers (13a and 13b) in rather low total yield (34%)
(Scheme 5). In addition, trans-1-ferrocenyl-2-methylcyclo-
propane (14) and three-membered ring-opening products,
viz., 1-ferrocenylbuta-1,3-diene (15) and 1-methyl-1H-
cyclopentaferrocene (16) were also isolated from the
reaction mixture (Scheme 5).
0.53 ppm is characteristic of (Z)-position of the ferrocenyl
and bromo sub- stituents, while |Dd| = 0.32 ppm is charac-
teristic of (E)-position.
1-Methyl-1H-cyclopentaferrocene (16) was isolated as
two diastereomers (16a and 16b, ca. 2:1), which could not
be separated by chromatography. However, their identifi-
cation based on spectroscopic data did not present any
problems (see Section 4). The formation of compounds
15, 16a, and 16b resulted apparently upon opening of the
three-membered rings in monobromides 13a and 13b into
allylic cation (18) (Scheme 6).
Deprotonation of the cation 18 affords 1-ferrocenyl-
buta-1,3-diene (15) and intramolecular alkylation of the
ferrocene unit results in compounds 16a,b.
Dehydrobromination of the monobromides 13a
and 13b with ButOK in DMSO [1–7] gave rise to 3-ferro-
cenyl-1-methyl- and 1-ferrocenyl-3-methylcyclopropenes
(7 and 8) in yields of 15–20%. In addition, 1-ferro-
cenylbuta-1,3-diene (15), 2-ferrocenylbuta-1,3-diene (19),
1-methyl-1H-cyclopentaferrocene (16a,b), and 2-methyl-
1H-cyclopentaferrocene (20) were obtained (Scheme 7).
All reaction products were separated by TLC on Al2O3
and characterized by 1H and 13C NMR spectroscopic data,
which confirm their structures, and data from elemental
analyses.
Ferrocenyl(methyl)cyclopropenes (7) and (8) represent
orange oils that are unstable in solutions and on storage.
In CHCl3, Me2CO, and CH2Cl2, they undergo rapid intra-
molecular transformations to give compounds 15, 16a,b,
19, and 20. Tentative mechanisms of the transformations
of ferrocenyl(methyl)cyclopropenes (7) and (8) are depicted
in Scheme 8.
Variation of the reduction conditions did not result in
increase in the yields of the monobromides (13a,b). Despite
the formation of a mixture of the reaction products, all of
them were isolated in individual form by TLC on Al2O3.
Their structures were unequivocally established based on
1H and 13C NMR spectroscopic data. The assignment of
(Fc, Br-Z)- and (Fc, Br-E)-configurations to the isomeric
monobromides, 13a and 13b, has been made based on
the 1H NMR spectroscopic data with account of the previ-
ously established NMR criteria for the determination of Z
and E configurations of bromo- (ferrocenyl)cyclopropanes
1
[1–7]. The H NMR spectra of these compounds contain
each two multiplets (d 1.09 and 1.16) for the methine pro-
tons of the CH–CH3 fragments and two doublets of dou-
blets (d 1.62 and 1.48) for the methine protons of the
CH–Fc fragments as AB-parts of ABM spin systems with
|Dd| = dA ꢀ dB = 0.53 and 0.32 ppm. The value |Dd| =
Br
Br
Fc
CH3
Fc
Br
Br
EtMgCl
H
Fc
+
+
+
Ti(OiPr)4
CH3
H
Fc
CH3
H
CH3
13a
13b
14
9
H
H
CH3
+
Fe
H
H
Fc
16a,b (25%)
15 (7%)
Scheme 5.
CH3
15
13a
13b
MgX2
H
CH3
Fc
H
Fc
16a,b
17
18
Scheme 6.

510
E.I. Klimova et al. / Journal of Organometallic Chemistry 691 (2006) 507–513
Fc
CH3
13a
13b
tBuOK
DMSO
15
+
16a,b
+
+
+
CH3
Fc
8
7
CH3
Fc
C
Fe
CH2
CH2
CH
+
19
20
Scheme 7.
H
O
Ph
H
C
Ph
CH3
H
16a,b
C
Fc
O
H
Fc
Ph
7
8
Ph
CH3
7
21
25
CH3
C
O
H
Ph
H
H
20
C
Fc
CH3
22
H
Fc
Ph
H
C
Fc
26
H
15
C
Scheme 9.
CH2
H
8
23
Data from 1H and 13C NMR spectra and elemental
Fc
analyses corroborate structures of these compounds.
Ferrocenylbuta-1,3-dienes (15) and (19) were character-
ized as the Diels–Alder adducts with N-phenylmaleimide,
viz., compounds 27 and 28 (Scheme 10).
The cycloaddition occurs stereospecifically, the adducts
are formed as single endo isomers. The assignment to the
endo-series was made on the basis of the known [14,15]
NMR criterion, viz., the high-field positions of the signals
for two protons of the substituted cyclopentadienyl rings
and one proton of the phenyl substituent relative to the
singlets of the protons of the C5H5 groups and multiplets
C
H
H
19
C
CH2
H
24
Scheme 8.
Opening of the small ring in ferrocenyl(methyl)cyclopro-
pene (7) gives rise in carbenoid intermediates 21 and 22,
which produce isomeric methyl-1H-cyclopentaferrocenes
16a,b and 20 as a result of intramolecular alkylation of
ferrocene. The carbenoids 23 and 24 formed from ferro-
cenyl(methyl)cyclopropene (8) are transformed into ferro-
cenylbuta-1,3-dienes (15) and (19).
O
O
C
C
HC
HC
N
Ph
N
Ph
C
O
C
Ferrocenyl(methyl)cyclopropenes (7) and (8) react ste-
reospecifically with 1,3-diphenylisobenzofuran to give clas-
sical [4 + 2]-cycloadducts 25 and 26, respectively, isolated
as single diastereomeric forms. By analogy with previously
described adducts of ferrocenylcyclopropenes [1–7,10],
compounds 25 and 26 have structures of exo-3-ferroce-
nyl-2-methyl- and exo-2-ferrocenyl-3-methyl-1,5-diphenyl-
6,7-benzo-8-oxatricyclo[3.2.1.02,4]oct-6-enes, respectively,
with anti-arranged ferrocenyl and methyl fragments
(Scheme 9).
O
15
19
Fc
27
O
C
HC
HC
O
N
Ph
C
C
O
N
Ph
C
Fc
O
28
Scheme 10.

E.I. Klimova et al. / Journal of Organometallic Chemistry 691 (2006) 507–513
511
of four protons of the phenyl substituents, which is typical
of endo isomers.
MS m/z(%): 398 (100). 1H NMR: d 1.44 (3H, d, CH3,
J = 6.3 Hz), 1.58 (1H, m, CH3, J = 6.3, 8.1 Hz), 2.18
(1H, d, CH, J = 8.1 Hz), 4.17 (5H, s, C5H5), 4.05 (1H, m,
C5H4), 4.15 (1H, m, C5H4), 4.20 (1H, m, C5H4), 4.36
(1H, m, C5H4). 13C NMR: d 17.43 (CH3); 31.71, 38.95
(2CH), 40.71 (C), 67.57, 67.99, 68.64, 69.58 (C5H4); 68.79
(C5H5); 83.87 (CipsoFc). Anal. Calc. for C14H14Br2Fe: C,
42.25; H, 3.55; Br, 40.16; Fe, 14.04. Found: C, 42.48; H,
3.27; Br, 40.23; Fe, 13.81%.
3. Conclusion
The results obtained in the present study make it possi-
ble to conclude that 3- and 1-ferrocenylcyclopropenes are
much less stable than 3-alkyl- and 3-aryl-3-ferrocenylcyclo-
propenes. They undergo smooth and rapid opening of the
three-membered rings at 20 ꢁC to give intramolecular
transformation products. They also give easily the
[4 + 2]-cycloadducts with 1,3-diphenylisobenzofuran. The
observed ease of intramolecular transformations is not typ-
ical of alkyl- and aryl-substituted analogs, which seems to
be related to peculiarities of reciprocal influence of the
ferrocene and cyclopropene fragments.
4.3. Reduction of the dibromide 9 with ethylmagnesium
chloride in the presence of titanium isopropoxide
Dibromo(ferrocenyl)methylcyclopropane (9) (1 mmol)
was added to a solution of EtMgCl (1.2 mmol) in dry ether
followed by several drops of titanium isopropoxide. The
mixture was stirred in an inert atmosphere for 3 h at room
temperature and quenched by addition of water (100 ml)
and benzene (100 ml). The organic layer was separated,
washed with water (2 · 20 ml) and benzene was evaporated
in vacuo. The residue was chromatographed on alumina
(hexane as the eluent) to give compounds 13a,b, 14, 15,
and 16a,b.
4. Experimental
All the solvents were dried according to the standard
procedures and were freshly distilled before use. Column
chromatography was carried out on alumina (Brockmann
1
activity III). The H and 13C NMR spectra were recorded
on a Unity Inova Varian spectrometer (300 and 75 MHz)
for solutions in CDCl3 with Me4Si as the internal standard.
The mass spectra were obtained on JEOL SX-102 A instru-
ment (EI MS, 70 eV). An Elemental Analysis System
GmbH was used for elemental analyses.
The following reagents were purchased from Aldrich:
ferrocene, 98%; propionyl chloride, 98%; ethylmagnesium
chloride (2.0 M solution in diethyl ether); titanium(IV) iso-
propoxide 99.999%; phosphorus oxychloride, 99%; N-
phenylmaleimide, 97%; 1,3-diphenylisobenzofuran, 97%;
bromoform, 96%; potassium tert-butoxide, 95%.
trans-1-Ferrocenyl-2-methylcyclopropane (14), yield
0.025 g (10%), yellow oil. MS m/z (%): 240 (100). 1H
NMR: d 0.57 (1H, m, CH2, J = 1.2, 5.4, 7.8 Hz), 0.64
(1H, m, CH2, J = 1.1, 5.4, 8.0 Hz), 0.85 (1H, m, CH,
J = 5.4, 7.2, 8.0 Hz), 1.11 (3H, d, CH3, J = 6.0 Hz), 1.21
(1H, m, CH), 4.12 (5H, s, C5H5), 3.98 (3H, m, C5H4),
4.10 (1H, m, C5H4). Anal. Calc. for C14H16Fe: C, 70.02;
H, 6.72; Fe, 23.26. Found: C, 69.89; H, 6.85; Fe, 23.31%.
(Fc, Br-Z)-1-Bromo-2-ferrocenyl-3-methylcyclopropane
(13a), yield 0.055 g (17%), yellow oil. MS m/z (%): 319
1
(100). H NMR: d 1.09 (1H, m, MeCH, J = 6.3, 7.5 Hz),
Propionylferrocene (10) was prepared by Friedel–Crafts
acylation of ferrocene with propionyl chloride in the pres-
ence of AlCl3 as described in [16], the yield was 86%, or-
ange oil. 1-(Hydroxypropyl)ferrocene (11) was obtained
by reduction of the ketone 10 with lithium aluminum hy-
dride in dry ether in an atmosphere of argon [17], the yield
was 80%, orange oil.
1.31 (3H, d, CH3, J = 6.3 Hz), 1.62 (1H, m, CH, J = 3.9,
6.3 Hz), 3.25 (1H, dd, CH, J = 3.9, 7.5 Hz), 4.17 (5H, s,
C5H5), 3.97 (1H, m, C5H4), 4.01 (1H, m, C5H4), 4.05
(2H, m, C5H4). 13C NMR: d 15.35 (CH3); 22.41, 28.69,
31.27 (3CH), 40.71 (C), 65.58, 66.34, 66.82, 68.96 (C5H4);
68.09 (C5H5); 88.07 (CipsoFc). Anal. Calc. for C14H15BrFe:
C, 52.71; H, 4.78; Br, 25.00; Fe, 17.51. Found: C, 52.84; H,
4.93; Br, 24.82; Fe, 17.71%.
4.1. trans/cis-1-Ferrocenylpropene (12a,b)
(Fc, Br-E)-1-Bromo-2-ferrocenyl-3-methylcyclopropane
(13b), yield 0.052 g (16%), yellow oil. MS m/z (%): 320
(100). H NMR: d 1.16 (1H, m, CH), 1.25 (3H, d, CH3,
J = 6.9 Hz), 1.48 (1H, m, CH), 3.05 (1H, dd, CH,
J = 4.2, 8.1 Hz), 4.11 (5H, s, C5H5), 4.00 (2H, m, C5H4),
4.24 (2H, m, C5H4). 13C NMR: d 16.23 (CH3); 24.05,
27.64, 33.12 (3CH), 42.16 (C), 67.04, 67.32, 67.45, 68.56
(C5H4); 68.23 (C5H5); 87.19 (CipsoFc). Anal. Calc. for
C14H15BrFe: C, 52.71; H, 4.78; Br, 25.00; Fe, 17.51.
Found: C, 52.56; H, 4.59; Br, 25.11; Fe, 17.32%.
1
Dehydration of the alcohol 11 with POCl3 in pyridine
[18] afforded the alkene 12 (12a:12b ꢁ 3:1) isolated by col-
umn chromatography on alumina (hexane as the eluent) in
70% yield, orange crystals, m.p. 39–40 ꢁC (lit. [19]: m.p. 39–
40 ꢁC).
4.2. trans-1,1-Dibromo-2-ferrocenyl-3-methylcyclopropane
(9)
1-Ferrocenyl-1,3-butadiene (15), Yield 0.017 g (7%), yel-
1
gem-Dibromocyclopropane (9) was obtained from the
alkenes 12a,b according to a standard procedure [3,4]. It
was isolated by column chromatography on alumina (hex-
ane as the eluent) in 68%, orange powder, m.p. 74–75 ꢁC.
low oil. MS m/z (%): 238 (100). H NMR: d 4.10 (5H, s,
C5H5), 4.18 (2H, m, C5H4), 4.27 (2H, m, C5H4), 5.03
(1H, dd, CH2@, J = 1.5, 10.5 Hz), 5.15 (1H, dt, CH2@,
J = 1.5, 10.5 Hz), 6.15 (1H, d, CH@, J = 17.4 Hz), 6.40

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E.I. Klimova et al. / Journal of Organometallic Chemistry 691 (2006) 507–513
(1H, dd, CH@, J = 7.8, 17.4 Hz), 7.00 (1H, m, CH@).
Anal. Calc. for C14H14Fe: C, 70.62; H, 5.92; Fe, 23.46.
Found: C, 70.47; H, 6.07; Fe, 23.29%.
2-Methyl-1H-cyclopentaferrocene (20), yield 0.025 g
(10%), orange crystals, m.p. 95–96 ꢁC. MS m/z (%): 238
(100). 1.82 (3H, d, CH3, J = 0.9 Hz), 2.36 (2H, s, CH2),
4.12 (5H, s, C5H5), 4.19 (2H, m, C5H3), 4.32 (1H, m,
C5H3), 7.11 (1H, d, CH@, J = 0.9 Hz). Anal. Calc. for
C14H14Fe: C, 70.62; H, 5.92; Fe, 23.46. Found: C, 70.73;
H, 6.11; Fe, 23.60%.
1-Methyl-1H-cyclopentaferrocene (16a,b) (ꢁ2:1), yield
0.10 g (40%), orange crystals, m.p. 89–91 ꢁC. MS m/z
(%): 238 (100). Anal. Calc. for C14H14Fe: C, 70.62; H,
5.92; Fe, 23.46. Found: C, 70.81; H, 5.87; Fe, 23.58%.
Compound 16a, 1H NMR: d 1.32 (3H, d, CH3,
J = 6.3 Hz), 4.09 (5H, s, C5H5), 4.20 (2H, m, C5H3), 4.32
(1H, m, C5H3), 4.37 (1H, q, CH, J = 6.3 Hz), 5.86 (1H,
dd, CH@, J = 6.3, 15.9 Hz), 6.29 (1H, d, CH@,
J = 15.9 Hz). 13C NMR: d 23.50 (CH3); 66.72 (CH),
67.00, 68.62, 68.68 (C5H3); 69.14 (C5H5); 82.47, 82.54
(2CipsoFc).
4.5. Reaction of cyclopropenes 7 and 8 with 1,3-diphenyl-
isobenzofuran
A mixture of compound 7 (or 8) (1 mmol) and 1,3-diph-
enylisobenzofuran (1.5 mmol) was stirred for 10 h at 20 ꢁC
in an inert atmosphere. The solvent was distilled off in va-
cuo. Chromatography of the residue on alumina (hexane –
ether, 3:1, as the eluent) afforded compound 25 (or 26).
Adduct 25, yield of 0.37 g (72%), yellow crystals, m.p.
192–193 ꢁC. MS m/z (%): 508 (100). 1H NMR: d 2.04
(3H, s, CH3), 2.28 (1H, d, CH, J = 5.7 Hz), 2.45 (1H, d,
CH, J = 5.7 Hz), 4.09 (5H, s, C5H5), 3.96 (1H, m, C5H4),
4.02 (1H, m, C5H4), 4.06 (1H, m, C5H4), 4.16 (1H, m,
C5H4), 7.32–7.67 (14H, m, Ar). 13C NMR: d 21.18
(CH3); 27.34, 43.90 (2CH), 35.06 (C), 65.85, 66.43, 68.52,
70.24 (C5H4); 68.56 (C5H5); 88.12 (2C–O), 91.09 (CipsoFc);
119.19, 120.12, 124.98, 126.03 (C6H4); 127.97, 128.14,
128.42, 128.55, 128.64, 129.19 (2C6H5); 135.81, 136.62,
148.99, 151.17 (4Cipso). Anal. Calc. for C34H28FeO: C,
80.32; H, 5.55; Fe, 10.98. Found: C, 80.46; H, 5.63; Fe,
10.82%.
Adduct 26, yield of 0.4 g (78%), yellow powder, m.p.
200–201 ꢁC. MS m/z (%): 508 (100). 1H NMR: d 1.60
(1H, m, CH), 1.71 (3H, d, CH3, J = 6.6 Hz), 2.51 (1H, d,
CH, J = 4.2 Hz), 4.01 (5H, s, C5H5), 3.46 (1H, m, C5H4),
3.79 (1H, m, C5H4), 3.96 (1H, m, C5H4), 4.00 (1H, m,
C5H4), 7.00–7.60 (14H, m, Ar). 13C NMR: d 13.44
(CH3); 26.92, 42.94 (2CH), 37.41 (C), 66.25, 66.33, 68.69,
70.95 (C5H4); 68.96 (C5H5); 88.29 (2C–O), 91.90 (CipsoFc);
119.30, 122.79, 125.11, 125.97 (C6H4); 127.90, 127.99,
128.12, 128.14, 128.32, 128.39 (2C6H5); 135.72, 136.68,
148.92, 150.93 (4Cipso). Anal. Calc. for C34H28FeO: C,
80.32; H, 5.55; Fe, 10.98. Found: C, 80.19; H, 5.70; Fe,
11.04%.
Compound 16b, 1H NMR: d 1.56 (3H, d, CH3,
J = 4.8 Hz), 4.11 (5H, s, C5H5), 4.24 (2H, m, C5H3), 4.36
(1H, m, C5H3), 4.41 (1H, qd, CH, J = 4.8, 6.1 Hz), 5.80
(1H, dd, CH@, J = 6.1, 15.0 Hz), 6.31 (1H, d, CH@,
J = 15.0 Hz). 13C NMR: d 23.62 (CH3); 66.57 (CH),
67.15, 68.35, 68.74 (C5H3); 69.18 (C5H5); 82.44, 82.58
(2CipsoFc).
4.4. Dehydrobromination of bromo(ferrocenyl)-
methylcyclopropanes (13a) and (13b)
A mixture of monobromide 13a (or 13b) (1 mmol) and
ButOK (1.5 mmol) in DMSO (20 ml) was stirred for 4 h
at 20 ꢁC. The reaction mixture was then partitioned be-
tween benzene (50 ml) and water (50 ml), the organic
layer was washed with water and concentrated in vacuo.
Chromatography of the residue on alumina (hexane as
the eluent) afforded compounds 7, 8, 15, 16a,b, 19, and
20.
3-Ferrocenyl-1-methylcyclopropene (7), yield 0.05 g
1
(20%), yellow oil. MS m/z (%): 238 (100). H NMR: d
1.81 (1H, d, CH, J = 1.8 Hz), 1.91 (3H, s, CH3), 4.12
(5H, s, C5H5), 4.05 (2H, m, C5H4), 4.02 (2H, m, C5H4),
6.83 (1H, d, CH@, J = 1.8 Hz). Anal. Calc. for
C14H14Fe: C, 70.62; H, 5.92; Fe, 23.46. Found: C, 70.74;
H, 5.87; Fe, 23.63%.
1-Ferrocenyl-3-methylcyclopropene (8), yield 0.06 g
(25%), yellow oil. MS m/z (%): 238(100). 1H NMR: d
1.20 (3H, d, CH3, J = 6.3 Hz), 1.86 (1H, qd, CH, J = 1.5,
6.3 Hz), 4.08 (5H, s, C5H5), 4.10 (2H, m, C5H4), 4.12
(2H, m, C5H4), 7.02 (1H, d, CH@, J = 1.5 Hz). Anal. Calc.
for C14H14Fe: C, 70.62; H, 5.92; Fe, 23.46. Found: C,
70.51; H, 5.97; Fe, 23.31%.
4.6. Reaction of ferroceny-1,3-butadienes 15 and 19 with
N-phenylmaleimide
A mixture of 1-ferrocenylbuta-1,3-diene 15 (or 19)
(1 mmol) and N-phenylmaleimide (1.2 mmol) in dry ben-
zene (20 ml) was stirred for 10 h at 30 ꢁC in an inert atmo-
sphere. The solvent was distilled off in vacuo and the
residue was chromatographed on alumina (hexane – ether,
3:1, as the eluent) to give N-phenyl-c-3-ferrocenyl-r-1, c-2-
cyclohex-4-enedicarboximide (27) (or N-phenyl-4-ferroce-
nylcyclohex-4-ene-cis-1,2-dicarboximide (28)).
Compounds 16a,b (ꢁ1:1), yield 0.03 g (12.5%), orange
crystals, m.p. 90–91 ꢁC. MS m/z (%): 238 (100).
2-Ferrocenyl-1,3-butadiene (19), yield 0.024 g (10%),
1
yellow oil. MS m/z (%): 238 (100). H NMR: d 4.14 (5H,
s, C5H5), 4.22 (2H, m, C5H4), 4.37 (2H, m, C5H4), 5.09
(1H, s, CH2@), 5.17 (1H, s, CH2@), 5.57 (1H, dd, CH2@,
J = 2.1, 10.2 Hz), 5.46 (1H, dd, CH2@, J = 4.8, 10.2 Hz),
6.37 (1H, dd, CH@, J = 2.1, 4.8 Hz). Anal. Calc. for
C14H14Fe: C, 70.62; H, 5.92; Fe, 23.46. Found: C, 70.79;
H, 5.78; Fe, 23.58%.
Adduct 27, yield of 0.26 g (65%), yellow powder, m.p.
173–174 ꢁC. MS m/z (%): 411 (100). 1H NMR: d 2.50
(1H, m, CH2), 2.58 (1H, m, CH2), 3.04 (1H, dd, CH,

E.I. Klimova et al. / Journal of Organometallic Chemistry 691 (2006) 507–513
513
´
´
[2] E.I. Klimova, T. Klimova Berestneva, L. Ru´ız Ramırez, M. Martınez
J = 9.0, 18.0 Hz), 3.25 (1H, dd, CH, J = 6.0, 9.0 Hz), 3.84
(1H, dd, CH, J = 6.0, 7.2 Hz), 4.11 (5H, s, C5H5), 3.92 (1H,
m, C5H4), 4.08 (1H, m, C5H4), 4.12 (1H, m, C5H4), 4.18
(1H, m, C5H4), 5.96 (1H, m, CH@), 6.42 (1H, dd, CH@,
J = 7.2, 8.9 Hz), 6.90–7.40 (5H, m, Ph). 13C NMR: d
24.72 (CH2); 38.25, 41.15, 47.64 (3CH), 67.25, 67.72,
68.70, 68.95 (C5H4); 68.80 (C5H5); 84.02 (CipsoFc);
120.98, 122.15 (2CH@); 126.75, 128.30, 128.93 (C6H5);
138.59 (Cipso), 177.64, 179.18 (2C@O). Anal. Calc. for
C24H21FeNO2: C, 70.09; H, 5.15; Fe, 13.58; N, 3.40.
Found: C, 69.92; H, 5.23; Fe, 13.74; N, 3.29%.
´
Garcıa, C. Alvarez Toledano, P.G. Espinoza, R.A. Toscano, J.
Organomet. Chem. 545–546 (1997) 191.
´
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[3] E.I. Klimova, L. Ruız Ramırez, R. Moreno Esparza, T. Klimova
´
´
Berestneva, M. Martınez Garcıa, N.N. Meleshonkova, A.V. Chura-
kov, J. Organomet. Chem. 559 (1998) 1.
´
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[4] E.I. Klimova, C. Alvarez Toledano, M. Martınez Garcıa, J. Gomez
Lara, N.N. Meleshonkova, I.G. Bolesov, Russ. Chem. Bull. 45 (1996)
550.
[5] E.I. Klimova, C. Alvarez Toledano, M. Martınez Garcıa, J. Gomez
Lara, N.N. Meleshonkova, I.G. Bolesov, Russ. Chem. Bull. 45 (1996)
613.
´
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[6] E.I. Klimova, M. Martinez Garcia, T. Klimova, C. Alvarez Toled-
´
´
ano, R.A. Toscano, L. Ruız Ramırez, J. Organomet. Chem. 598
Adduct 28, yield 0.28 g (70%), yellow plates, m.p. 164–
(2000) 254.
1
165 ꢁC. MS m/z (%): 411 (100). H NMR: d 2.32 (1H, m,
[7] E.I. Klimova, M. Martinez Garcia, T. Klimova, C. Alvarez Toled-
CH2), 2.54 (1H, m, CH2), 2.63 (1H, dd, CH2, J = 4.5,
9.3 Hz), 2.74 (1H, dd, CH2, J = 5.7, 9.3 Hz), 3.21 (1H, m,
CH), 3.62 (1H, m, CH), 4.17 (5H, s, C5H5), 3.98 (1H, m,
C5H4), 4.05 (1H, m, C5H4), 4.19 (1H, m, C5H4), 4.28
(1H, m, C5H4), 6.09 (1H, dd, CH@, J = 8.1,
17.3 Hz),7.06–7.53 (5H, m, Ph). 13C NMR: d 24.72,26.45
(2CH2); 41.06, 46.89 (2CH), 67.12, 67.67, 68.56, 69.08
(C5H4); 68.89 (C5H5); 84.31 (CipsoFc); 121.34 (CH@);
126.98, 127.37, 128.78 (C6H5); 131.12 (C); 139.24 (Cipso),
178.03, 179.27 (2C@O). Anal. Calc. for C24H21FeNO2: C,
70.09; H, 5.15; Fe, 13.58; N, 3.40. Found: C, 70.21; H,
5.09; Fe, 13.39; N, 3.32%.
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ano, R.A. Toscano, L. Ruız Ramırez, J. Organomet. Chem. 605
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L.S. Surmina, I.G. Bolesov, Dokl. Akad. Nauk SSSR. 254 (1980)
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[11] J.A. Connor, J.P. Lloyd, J. Chem. Soc. Perkin I (1973) 17.
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Acknowledgements
(1987) 1102.
This work was supported by the grant DGAPA-UNAM
(Mexico, grant IN 207102-3). Thanks are due to J.M.
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Klimova, I.V. Martinov, Bull. Akad. Sci. USSR, Div. Chem. Sci. 35
(1986) 642.
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Martınez Mendoza and R.I. Del Villar Morales for their
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technical assistance.
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