N-ferrocenoyl benzotriazole: A convenient tool for the synthesis of ferrocenoyl esters

Article abstract of DOI:10.1016/j.jorganchem.2009.11.015

A new synthesis methodology has been presented for the preparation of the ferrocenoyl esters. Ferrocene carboxylic acid was derivatized using direct 1H-benzotriazole/SOCl₂ methodology to prepare N-ferrocenoyl benzotriazole as a convenient tool for the functionalization of ferrocene ring. N-ferrocenoyl benzotriazole was reacted with alcohols in mild conditions to prepare ferrocenoyl esters in high purity and in good yield. The solid state structure of benzyl-1-ferrocenoate, 2f, has also been determined by X-ray crystallography. In the crystal structure, intermolecular C-H···O hydrogen bonds link the molecules into a two-dimensional network. The π···π contacts between the cyclopentadiene rings and cyclopentadiene and phenyl rings, [centroid-centroid distances = 3.296(1) and 3.750(1) A?] may further stabilize the structure. Two weak C-H···π interactions are also found.

Full text of DOI:10.1016/j.jorganchem.2009.11.015

Journal of Organometallic Chemistry 695 (2010) 1031–1034
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
N-ferrocenoyl benzotriazole: A convenient tool for the synthesis
of ferrocenoyl esters
*
Deniz Hür , Sultan Funda Ekti, Hakan Dal
Anadolu University, Faculty of Science, Department of Chemistry, 26470 Eskißsehir, Turkey
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 5 October 2009
Received in revised form 12 November 2009
Accepted 13 November 2009
Available online 18 November 2009
A new synthesis methodology has been presented for the preparation of the ferrocenoyl esters. Ferrocene
carboxylic acid was derivatized using direct 1H-benzotriazole/SOCl2 methodology to prepare N-ferroce-
noyl benzotriazole as a convenient tool for the functionalization of ferrocene ring. N-ferrocenoyl benzo-
triazole was reacted with alcohols in mild conditions to prepare ferrocenoyl esters in high purity and in
good yield. The solid state structure of benzyl-1-ferrocenoate, 2f, has also been determined by X-ray crys-
tallography. In the crystal structure, intermolecular C–HÁÁÁO hydrogen bonds link the molecules into a
Keywords:
Ferrocene
Ferrocene esters
Benzotriazole
N-acyl benzotriazole
two-dimensional network. The
p
ÁÁÁ
p contacts between the cyclopentadiene rings and cyclopentadiene
and phenyl rings, [centroid–centroid distances = 3.296(1) and 3.750(1) Å] may further stabilize the struc-
ture. Two weak C–HÁÁÁ
p
interactions are also found.
Ó 2009 Elsevier B.V. All rights reserved.
1. Introduction
2. Results and discussion
Ferrocene chemistry and its applications have been studied to a
considerable degree since it was first prepared unintentionally and
characterized. Current areas of concern in ferrocene chemistry con-
tain the preparation of ferrocene based catalyst [1], sensors [2] and
immunoassay reagents [3–10].
All spectroscopic data collected for the starting material 1 was
in agreement with literature [16]. Starting material 1 was treated
with an equimolar amount of alcohol in THF at room temperature
for 15 min. to give the corresponding ferrocenoyl esters 2a–l. The
1H NMR spectra of the products show no signals corresponding
to these assigned to the N-substituted benzotriazole groups of
starting material 1 (between 7.5 and 8.5 ppm two doublet and
two triplet.). The 13C NMR spectra of these compounds also no
longer show signals for a N-substituted benzotriazole group
(chemical shifts around 120 and 146 ppm). Ferrocenoyl ester prod-
ucts show characteristic mono substituted ferrocene peaks around
4.0–5.0 ppm in 1H NMR and 69–75 ppm in 13C NMR. No significant
shift was observed for the carbonyl carbon (around 170 ppm) dur-
ing the transformation from starting material 1 to products 2a–l.
The products list was given in Table 1 with overall yields.
Ferrocene has a rich chemistry by virtue of capability for the
preparation of a large number of derivatives. Ferrocenoyl esters
have extensive applications. Ferrocenoyl esters were synthesized
as a ferrocenyl carbohydrate conjugates and their biological activ-
ities have been investigated [11]. Additionally, ferrocenoyl esters
have been obtained as a product in the reactions of ferrocene with
solvent radicals under arylation conditions [12]. Ferrocenoyl esters
are used as a substrate in photochemical rearrangement [13], as a
Cp donor in the double ligand-transfer reaction [14]. A general
intermediate for the synthesis of these kind of systems is ferroce-
noylchloride. It is known that to obtain chlorocarbonyl ferrocene is
fairly hard. Formation of this compound from the corresponding
acids is capricious and can result in low yields [15].
2.1. X-ray structure of 2f
In our previous literature we have used 1H-benzotriazole/
SOCl2 methodology for the preparation of novel N-ferrocenyl
benzotriazole 1 as starting material for the derivatisation of
ferrocenoyl group [16] following the Katritzky’s methodology
[17] (Scheme 1).
The X-ray structural determination of compound 2f confirms
the assignment of its structure from spectroscopic data. The molec-
ular structure of compound 2f along with the atom-numbering
scheme is depicted in Fig. 1, in which the bond lengths and angles
are within normal ranges.
Rings A (C1–C5), B (C6–C10) and C (C13–C18) are, of course, pla-
nar. The dihedral angles between the rings are A/B = 1.90(7)°, A/
C = 88.07(5)° and B/C = 88.48(6)°. The (O1/O2/C9/C11/C12) moiety
is nearly planar [with a maximum deviation of 0.1113(17) Å for
* Corresponding author. Tel.: +90 222 3350580; fax: +90 222 3204910.
E-mail address: dhur@anadolu.edu.tr (D. Hür).
0022-328X/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2009.11.015

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D. Hür et al. / Journal of Organometallic Chemistry 695 (2010) 1031–1034
3.2. X-ray crystallography
O
O
O
HO
R
BtH, SOCl
2
R
O
, 25 o
C
THF,r.t 15 min
NaH
Fe
Fe
Fe
CH Cl
2
2
Orange crystals of compound 2f were crystallized from ethyl
acetate/hexane mixture at room temperature. The selected bond
lengths and angles are given in Table 2, crystallographic data are
listed in Table 3 and the hydrogen bond data are given in Table
4. Crystallographic data were recorded on a Bruker Kappa APEXII
N
OH
N
N
2a-l
Bt=benzotriazole-1-yl
1
Scheme 1. Preparation of ferrocenoyl esters.
CCD area-detector diffractometer using Mo
Ka radiation
(k = 0.71073 Å) at T = 100(2) K. Absorption correction by multi-
scan [18] was applied. Structure was solved by direct methods
and refined by full-matrix least squares against F2 using all data
[19]. All non-H atoms were refined anisotropically. H atom posi-
tions were calculated geometrically at distances of 0.93 Å (CH)
and 0.97 Å (CH2) from parent C atoms; a riding model was used
during the refinement process and the Uiso(H) values were con-
strained to be 1.2 Ueq (carrier atom).
atom C12] and it is oriented with respect to rings A, B and C at
dihedral angles of 20.05(7)°, 18.34(7)° and 79.97(5)°, respectively.
In the crystal structure, intermolecular C–HÁÁÁO hydrogen bonds
(Table 4) link the molecules into a two-dimensional network, in
which they may be effective in the stabilization of the structure.
The
p p contacts between the cyclopentadiene rings and cyclo-
ÁÁÁ
pentadiene and phenyl rings, Cg1ÁÁÁCg2 and Cg1ÁÁÁCg3i [symmetry
code: (i) 1Àx, Ày, 1Àz, where Cg1, Cg2 and Cg3 are centroids of
the rings A (C1–C5), B (C6–C10) and C (C13–C18), respectively]
may further stabilize the structure, with centroid–centroid dis-
3.3. General procedure for the preparation of ferrocenoyl esters
tances of 3.296(1) and 3.750(1) Å, respectively. Two weak C–HÁÁÁ
p
interactions (Table 4) are also found.
To a solution of an appropriate alcohol (1 eq) in freshly distilled
THF in the presence of NaH in a round bottom flask, solution of
FcCOBt, 1, (1 eq), solved in THF, was added dropwise under nitro-
gen atmosphere and the reaction mixture was stirred at 25 °C for
30 min. After the solvent was evaporated under vacuum, the reac-
tion mixture was added ethylacetate, washed with 20% water solu-
tion of Na2CO3 to remove free 1H-benzotriazole (Bt-H). The
collected organic layers were dried over MgSO4. After evaporation
of the solvent, crude product purified via column chromatography
using ethyl acetate:hexanes (1:5) mixture as eluent. Solvent was
evaporated under vacuum to obtain ferrocenoyl esters in good
yields. Only compound 2f was recrystallized in ethyl acetate:hex-
anes (1:5) mixture for X-ray analysis.
3. Experimental
3.1. General
THF was used freshly after distillation with sodium in presence
of benzophenone. Column chromatography was conducted with
silica gel 200–425 mesh. Melting points were determined on a
hot-stage apparatus and were uncorrected. NMR spectra were re-
corded in CDCl3 with TMS as the internal standard for 1H (500
MHz) or a solvent as the internal standard for 13C (125 MHz) using
Bruker NMR equipment.
Table 1
Alcohols for the preparation of ferrocenylesters
Entry
1
Product
R
Yield (%)
82
Entry
7
Product
R
Yield (%)
38
2a
2g
H3C
cinnamyl alcohol
p-cresol
CH3
2
2b
70
8
2h
83
o-cresol
Cl
4-chlorophenol
3
4
2c
79
75
9
2i
2j
55
80
O
allyl alcohol
furfuryl alcohol
2d
10
propargyl alcohol
phenol
5
6
2e
2f
87
85
11
12
2k
2l
43
30
hexan-1-ol
cyclohexanol
benzyl alcohol
NH2
5-amino,1-naphthol

D. Hür et al. / Journal of Organometallic Chemistry 695 (2010) 1031–1034
1033
Table 3
Crystallographic data for 2f.
Empirical formula
Formula weight
Crystal system
Space group
a (Å)
C18H16FeO2
320.17
Monoclinic
P21/n
5.8534(1)
26.2786(5)
8.9849(2)
90.00
b (Å)
c (Å)
a
(°)
b (°)
91.845(1)
90.00
1381.33(5)
4
1.092
1.54
c
(°)
V (Å3)
Z
l
q
(cmÀ1
)
(calcd) (g cmÀ1
)
Number of reflections collected
Number of reflections total
Number of reflections unique
Rint
12 704
3381
2762
0.035
2hmax (°)
56.62
Tmin/Tmax
0.617/0.853
190
0.0314
0.0666
Number of parameters
R [F2 > 2
r
(F2)]
Fig. 1. The molecular structure of 2f, with the atom-numbering scheme. Displace-
ment ellipsoids are drawn at the 50% probability level.
wR
1-(Ferrocenylcarbonyl)-1H-benzotriazole, 1, (dark-red needles,
79%), m.p. 152–154 °C. 1HNMR (500 MHz, CDCl3, 25 °C): d = 8.42
(d, 3JH,H = 8.36 Hz, 1H, Bt-ring), 8.18 (d, 3JH,H = 8.22 Hz, 1H, Bt-ring),
3
6.42 (dd, JH,H = 3.15 Hz, 1.89 Hz, 1H, furan ring), 5.25 (s, 2H, –
3
CH2–O–), 4.84 (t, JH,H = 1.89 Hz, 2H, subst. Cp ring), 4.41 (t,
3JH,H = 1.89 Hz, 2H, subst. Cp ring), 4.13 (s, 5H, Cp ring) ppm.
13C NMR (125 MHz, CDCl3, 25 °C): d = 171.2, 150.0, 143.1, 110.7,
71.6, 70.3, 69.8, 69.7, 57.5, 29.7 ppm.
3
3
7.70 (t, JH,H = 7.67 Hz, 1H, Bt-ring), 7.55 (t, JH,H = 7.67 Hz, 1H, Bt-
3,4
ring), 5.60 (t,
J
= 1.57 Hz, 2H, subst. Cp ring), 4.78 (t,
H,H
3JH,H = 1.57 Hz, 2H, subst. Cp ring), 4.26 (s, 5H, Cp ring) ppm.
13C NMR (125 MHz, CDCl3, 25 °C): d = 170.4, 145.5, 132.2, 130.1,
125.9, 120.0, 115.0, 73.5, 73.1, 71.0, 70.5 ppm.
Elemental Anal. Calc. for C16H14FeO3: C, 61.97; H, 4.55. Found: C,
61.74; H, 4.27%.
Phenyl-1-ferrocenoate, 2d, (red microcrystals, 75%). m.p. 119–
Elemental Anal. Calc. for C17H13FeN3O: C, 61.66; H, 3.96; N,
12.69. Found: C, 61.43; H, 3.87; N, 12.72%.
122 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 7.46 (t, 3JH,H = 7.57 Hz,
3
2H, Ph ring), 7.29 (t, JH,H = 7.57 Hz, 1H, Ph ring), 7.21 (d,
(4-Methylphenyl)-1-ferrocenoate, 2a, (brown microcrystals,
3JH,H = 7.57 Hz, 1H, Ph ring), 5.00 (t, JH,H = 1.89 Hz, 2H, subst. Cp
3
82%). m.p. 90–94 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 7.24 (d,
ring), 4.53 (t, 3JH,H = 1.89 Hz, 2H, subst. Cp ring), 4.34 (s, 5H, Cp ring)
ppm.
3
3JH,H = 8.20 Hz, 2H, Ph ring), 7.09 (d, JH,H = 8.51 Hz, 2H, Ph ring),
4.99 (t,3JH,H = 1.89 Hz, 2H, subst. Cp ring), 4.52 (t,,3JH,H = 1.89 Hz,
2H, subst. Cp ring), 4.33 (s, 5H, Cp ring), 2.40 (s, 3H, Ph-CH3) ppm.
13C NMR (125 MHz, CDCl3, 25 °C): d = 170.5, 148.7, 135.2, 129.9,
121.4, 71.9, 70.6, 70.3, 69.9, 21.0 ppm.
13C NMR (125 MHz, CDCl3, 25 °C): d = 170.4, 160.0, 129.5, 125.7,
121.9, 72.0, 70.7, 70.2, 70.0 ppm.
Elemental Anal. Calc. for C17H14FeO2: C, 66.70; H, 4.61. Found: C,
66.38; H, 4.96%.
Elemental Anal. Calc. for C18H16FeO2: C, 67.53; H, 5.04. Found: C,
67.91; H, 5.17%.
Cyclohexyl-1-ferrocenoate, 2e, (brown microcrystals, 87%). m.p.
67–70 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 4.97 (m, 1H,
(2-Methylphenyl)-1-ferrocenoate, 2b, (orange microcrystals,
3
70%). m.p. 106–109 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 7.29
–CH–O–), 4.84 (t, JH,H = 1.89 Hz, 2H, subst. Cp ring),4.40 (d,
3JH,H = 1.89 Hz, 2H, subst. Cp ring), 4.22 (s, 5H, Cp ring), 1.94 (m,
2H, cyclohexyl ring), 1.81 (m, 2H, cyclohexyl ring), 1.58 (m, 2H, cyclo-
hexyl ring), 1.47 (m, 2H, cyclohexyl ring) ppm.
3
3
(t, JH,H = 7.88 Hz, 1H, Ph ring), 7.27 (d, JH,H = 7.57 Hz, 1H, Ph ring),
3
3
7.19 (t, JH,H = 7.25 Hz, 1H, Ph ring), 7.14 (d, JH,H = 7.88 Hz, 1H, Ph
ring), 5.01 (t,3JH,H = 1.89 Hz, 2H, subst. Cp ring), 4.53 (t,,3JH,H
=
13C NMR (125 MHz, CDCl3, 25 °C): d = 171.0, 128.6, 71.9, 71.1,
70.1, 69.7, 31.9, 29.7, 25.6, 23.7 ppm.
1.89 Hz, 2H, subst. Cp ring), 4.34 (s, 5H, Cp ring), 2.32 (s, 3H, Ph-
CH3) ppm.
13C NMR (125 MHz, CDCl3, 25 °C): d = 170.0, 149.6, 131.1, 130.2,
126.9, 125.7, 122.1, 71.8, 70.6, 70.5, 69.8, 16.3 ppm.
Elemental Anal. Calc. for C18H16FeO2: C, 67.53; H, 5.04. Found: C,
67.73; H, 5.34%.
Elemental Anal. Calc for C17H20FeO2: C, 65.40; H, 6.46. Found: C,
65.18; H, 6.85%.
Benzyl-1-ferrocenoate, 2f, (orange microcrystals, 85%). m.p. 88–
93 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 7.50 (d, 3JH,H = 7.12 Hz,
2H, Ph ring), 7.44–7.39 (m, 3H, Ph ring), 4.87 (s, 2H, PhCH2–), 4.73(s,
2H, subst. Cp ring), 4.43 (s, 2H, subst. Cp ring), 4.14 (s, 5H, Cp ring)
ppm.
Furfuryl-1-ferrocenoate, 2c, (orange microcrystals, 79%). m.p.
3
87–89 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 7.48 (d, JH,H
=
3
1.37 Hz, 1H, furan ring), 6.52 (d, JH,H = 3.15 Hz, 1H, furan ring),
Table 2
Selected bond lengths (Å) and angles (°) for 2f.
Fe1–C1
Fe1–C2
Fe1–C3
Fe1–C4
Fe1–C5
O1–C11–O2
C9–C11–O1
2.0546(18)
2.0488(19)
2.0383(19)
2.0330(18)
2.0471(17)
123.80(16)
123.85(16)
Fe1–C6
Fe1–C7
Fe1–C8
Fe1–C9
Fe1–C10
C9–C11–O2
C11–O2–C12
2.0500(17)
2.0489(17)
2.0436(17)
2.0327(17)
2.0371(17)
112.34(14)
115.97(13)
C9–C11
C11–O1
C11–O2
C12–O2
C12–C13
O2–C12–C13
1.468(2)
1.211(2)
1.349(2)
1.471(2)
1.503(2)
109.02(14)

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D. Hür et al. / Journal of Organometallic Chemistry 695 (2010) 1031–1034
Table 4
(5-Amino,1-nafthyl)-1-ferrocenoate, 2l, (orange microcrystals,
30%). m.p. 153–155 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 7.76
(d, 3JH,H = 8.51 Hz, 1H, Ph ring), 7.66 (d, 3JH,H = 8.51 Hz, 1H, Ph ring),
Hydrogen-bond geometry (Å, °).
D–HÁÁÁA
D–H
HÁÁÁA
DÁÁÁA
D–HÁÁÁA
3
3
7.58 (d, JH,H = 8.51 Hz, 1H, Ph ring), 7.50 (t, JH,H = 7.88 Hz, 1H, Ph
C12–H12AÁÁÁO1i
C14–H14ÁÁÁO1i
C3–H3ÁÁÁCg2ii
C5–H5ÁÁÁCg3
0.97
0.93
0.93
0.93
2.49
2.56
2.82
2.63
3.333(2)
3.362(2)
3.717(2)
3.536(2)
145
145
164
166
3
3
ring), 7.41 (d, JH,H = 8.51 Hz, 1H, Ph ring), 7.38 (d, JH,H = 7.88 Hz,
1H, Ph ring), 6.84 (s, 2H, –NH2), 5.11 (s, 2H, subst. Cp ring), 4.58
(s, 2H, subst. Cp ring), 4.39 (s, 5H, Cp ring) ppm.
13C NMR (125 MHz, CDCl3, 25 °C): d = 170.4, 142.4, 142.2, 126.9,
124.2, 118.7, 118.3, 112.0, 110.2, 113.5, 109.0, 72.0, 70.7, 70.3,
70.0 ppm.
Symmetry codes: (i) xÀ1, y, z (ii) xÀ3/2, ÀyÀ1/2, zÀ3/2.
13C NMR (125 MHz, CDCl3, 25 °C): d = 171.6, 141.0, 136.7, 128.7,
128.4, 127.0, 71.5, 70.3, 69.8, 65.9 ppm.
Elemental Anal. Calc. for C21H17NFeO2: C, 67.95; H, 4.62; N, 3.77.
Found: C, 67.73; H, 4.37; N, 3.84%.
Elemental Anal. Calc. for C18H16FeO2: C, 67.53; H, 5.04. Found: C,
67.83; H, 5.36%.
4. Conclusion
Cinnamyl-1-ferrocenoate, 2g, (orange microcrystals, 38%). m.p.
3
96–98 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 7.46 (d, JH,H
=
In this work, we prepared ferrocene esters by using N-ferroce-
noyl benzotriazole which was reacted with alcohols under mild
conditions and obtained ferrocenoyl esters in high purity and in
good yields. In addition, it is easy to monitor the progress of the
reaction and the reaction time is quite short.
3
7.57 Hz, 2H, Ph ring), 7.37 (t, JH,H = 7.25 Hz, 1H, Ph ring), 7.29 (t,
3JH,H = 7.25 Hz, 2H, Ph ring), 6.77 (d, JH,H = 15.76 Hz, 1H, Ph–
3
3
CH@CH–), 6.42 (dt, JH,H = 6.31 Hz, 15.76 Hz, 2H, Ph–CH@CH–),
3
3
4.92 (d, JH,H = 6,32 Hz, 2H, CH@CH–CH2–O–), 4.88 (t, JH,H
=
3
1.58 Hz, 2H, subst. Cp ring), 4.44 (t, JH,H = 1.58 Hz, 2H, subst. Cp
ring), 4,24 (s, 5H, Cp ring) ppm.
13C NMR (125 MHz, CDCl3, 25 °C) d = 171.5, 136.4, 133.9, 128.7,
128.0, 126.6, 123.8, 71.4, 71.1, 70.2, 69.8, 64.7 ppm.
Elemental Anal. Calc. for C20H18FeO2: C, 69.39; H, 5.24. Found: C,
69.21; H, 5.57%.
Acknowledgements
This project has been supported by The Scientific and Techno-
logical Council of Turkey. Project number: 107T931.Authors would
like to thank AUBIBAM for the NMR and X-ray analysis. Authors
also would like to thank to Tuncer Hökelek.
(4-Chlorophenyl)-1-ferrocenoate, 2h, (brown microcrystals, 83%).
m.p. 98.3–101.3 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 7.41 (d,
3JH,H = 8.83 Hz, 2H, Ph ring), 7.15 (d, JH,H = 8.83 Hz, 2H, Ph ring),
3
3
3
4.98 (t, JH,H = 1.89 Hz, 2H, subst. Cp ring), 4.54 (t, JH,H = 1.89 Hz,
2H, subst. Cp ring), 4.33 (s, 5H, Cp ring) ppm.
Appendix A. Supplementary material
13C NMR (125 MHz, CDCl3, 25 °C): d = 170.2, 149.4, 131.1, 129.4,
123.2, 72.2, 70.7, 70.0, 69.8 ppm.
CCDC 749578 contains the supplementary crystallographic data
for compound 2f. These data can be obtained free of charge from
The Cambridge Crystallographic Data Centre via www.ccdc.cam.a-
c.uk/data_request/cif. Supplementary data associated with this
article can be found, in the online version, at doi:10.1016/
j.jorganchem.2009.11.015.
Elemental Anal. Calc. for C17H13ClFeO2: C, 59.95; H, 3.85. Found:
C, 61.21; H, 3.67%.
Allyl-1-ferrocenoate, 2i, (red microcrystals, 55%). m.p. 36–38 °C.
1H NMR (500 MHz, CDCl3, 25 °C): d = 6.05 (m, 1H, CH2@CH–CH2–
3
3
), 5.44 (d, JH,H = 17.34 Hz, 1H, CH2@CH–CH2–), 5.31 (d, JH,H
=
10.40 Hz, 1H, CH2@CH–CH2–), 4.86 (s, 2H, subst. Cp ring), 4.75 (d,
3JH,H = 5.67 Hz, 2H, CH2@CH–CH2–O–), 4.43 (s, 2H, subst. Cp ring),
4.23 (s, 5H, Cp ring) ppm.
References
13C NMR (125 MHz, CDCl3, 25 °C): d = 171.5, 132.9, 118.0, 117.8,
71.5, 71.1, 70.0, 65.0 ppm.
[1] T. Hayashi, A. Togni, Ferrocenes: Homogeneous Catalysis, Organic Synthesis,
Materials Science, VCH, Weinheim and Newyork, 1995 (Chapter 2).
[2] T.E. Edmonds, Chemical Sensors, Blackie, Glasgow and London, 1988 (Chapter
8).
[3] S.-J. Choi, B.-G. Choi, S.-M. Park, Anal. Chem. 74 (2002) 1998–2002.
[4] N.J. Forrow, N.C. Foulds, J.E. Frew, J.T. Law, Bioconjugate Chem. 15 (2004) 134–
144.
[5] C.E. Immoos, S.J. Lee, M.W. Grinstaff, J. Am. Chem. Soc. 126 (2004) 10814–
10815.
[6] J. Liu, S. Tian, L. Tiefenauer, P.E. Nilesen, W. Knoll, Anal. Chem. 77 (2005) 2756–
2761.
[7] W. Tarraga, P. Molina, J.L. Lopez, M.D. Velasco, D. Bautisla, P.G. Jones,
Organometallics 21 (2002) 2055–2065.
[8] F. Tompatanaget, T. Tuntulani, O. Chailapakul, Org. Lett. 5 (2003) 1539–1542.
[9] I. Willner, E. Katz, Angew. Chem., Int. Ed. 39 (2000) 1180–1218.
[10] C.J. Yu, H. Wang, Y. Yowanta, J.C. Kim, L.H. Donilon, C. Tao, M. Strong, Y.J.
Chong, Org. Chem. 66 (2001) 2937–2942.
[11] C.L. Ferreira, C.B. Ewart, C.A. Barta, S. Little, V. Yardley, C. Martins, E.
Polishchuk, P.J. Smith, J.R. Moss, M. Merkel, M.J. Adam, C. Orvig, Inorg. Chem.
45 (2006) 8414–8422.
[12] W.F. Little, K.N. Lynn, R. Williams, J. Am. Chem. Soc. 85 (19) (1963) 3055–3056.
[13] D. Bellu, P. Hrdlovi, Chem. Rev. 67 (6) (1967) 599–609.
[14] T.W. Spradau, J.A. Katzenellenbogen, Organometallics 17 (10) (1998) 2009–
2017.
Elemental Anal. Calc. for C14H14FeO2: C, 62.25; H, 5.22. Found: C,
62.20; H, 5.37%.
2-Propynyl-1-ferrocenoate, 2j, (red microcrystals, 80%). m.p. 86–
89 °C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 4.88 (s, 2H, –CH2–O–),
4.84 (s, 2H, subst. Cp ring), 4.45 (s, 2H, subst. Cp ring), 4.27 (s, 5H, Cp
ring), 2.53 (s, 1H, HC„C–) ppm.
13C NMR (125 MHz, CDCl3, 25 °C) d = 171.1, 78.8, 74.5, 71.8,
71.3, 70.3, 69.8, 51.7 ppm.
Elemental Anal. Calc. for C14H12FeO2: C, 62.72; H, 4.51. Found: C,
62.54; H, 4.27%.
Hexyl-1-ferrocenoate, 2k, (orange microcrystals, 43%). m.p. 82–84
°C. 1H NMR (500 MHz, CDCl3, 25 °C): d = 4.83 (t, 3JH,H = 1.89 Hz, 2H,
3
subst. Cp ring), 4.41 (t, JH,H = 1.89 Hz, 2H, subst. Cp ring), 4.24 (t,
3JH,H = 6.62 Hz, 2H, CH3–(CH2)4–CH2–O–), 4.20 (s, 5H, Cp ring),
3
1.75 (p, JH,H = 6.63, 7.45 Hz, 2H, (–CH2–CH2–O–), 1.47 (m, 2H),
3
1.39 (m, 2H), 1.28 (m, 2H), 0.95 (t, JH,H = 6.94 Hz, 3H, CH3–
(CH2)4–) ppm.
[15] T.H. Galow, J. Rodrigo, K. Cleary, G. Cooke, V.M. Rotello, J. Org. Chem. 64 (10)
(1999) 3745–3746.
[16] S.F. Ekti, D. Hür, Inorg. Chem. Commun. 11 (2008) 1027–1029.
[17] A.R. Katritzky, Y. Zhang, S.K. Singh, Synthesis 18 (2003) 2795–2798.
[18] Bruker, SADABS, Bruker AXS Inc., Madison, Wisconsin, USA, 2005.
[19] G.M. Sheldrick, Acta Crystallogr., Sect. A 64 (2008) 112–122.
13C NMR (125 MHz, CDCl3, 25 °C) d = 171.8, 71.6, 71.2, 70.1,
69.7, 64.3, 31.5, 28.9, 25.8, 22.6, 14.0 ppm.
Elemental Anal. Calc. for C17H22FeO2: C, 64.98; H, 7.06. Found: C,
70.24; H, 7.41%.