Imidazolidinium ferrate complexes: Synthesis and catalytic properties

Article abstract of DOI:10.1016/j.crci.2014.03.015

The new well-defined and air stable anionic iron complexes bearing an imidazolidinium ligand (2a-d) have been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction studies. Starting from FeBr₂, [imidazolidinium][FeBr₄] complexes 2a and 2b were prepared. The reaction of imidazolidinium chlorides with Fe(OAc)₂, followed by a recrystallization in the air led to bis(imidazolidinium) μ-oxido-bis[trichloroferrate(III)] complexes 2c and 2d. The catalytic activity of these novel complexes has been evaluated in the cross-coupling reactions of alkyl halides with Grignard reagents.

Full text of DOI:10.1016/j.crci.2014.03.015

G Model
CRAS2C-3929; No. of Pages 8
C. R. Chimie xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Comptes Rendus Chimie
www.sciencedirect.com
Full paper/M e´ moire
Imidazolidinium ferrate complexes: Synthesis and catalytic
properties
a
a
b
c
Serpil Demir , Yasemin G o¨ k c¸ e , Thierry Roisnel , Jean-Baptiste Sortais ,
c
a,
˙
¨
Christophe Darcel , Ismail Ozdemir *
a
In o¨ n u¨ University, Catalysis Research and Application Centre, 44280 Malatya, Turkey
b
Centre de diffractom e´ trie X, UMR 6226 CNRS–Universit e´ de Rennes-1 « Sciences chimiques de Rennes », 35042 Rennes cedex, France
c
UMR 6226 CNRS–Universit e´ de Rennes-1, Institut des sciences chimiques de Rennes, Organometallics: Materials and Catalysis – Centre for
Catalysis and Green Chemistry, 35042 Rennes cedex, France
A R T I C L E I N F O
A B S T R A C T
Article history:
The new well-defined and air stable anionic iron complexes bearing an imidazolidinium
Received 4 February 2014
Accepted after revision 27 March 2014
Available online xxx
ligand (2a–d) have been synthesized and characterized by elemental analysis and single-
crystal X-ray diffraction studies. Starting from FeBr
a and 2b were prepared. The reaction of imidazolidinium chlorides with Fe(OAc)
followed by recrystallization in the air led to bis(imidazolidinium) -oxido-
2 4
, [imidazolidinium][FeBr ] complexes
2
2
,
a
m
Keywords:
bis[trichloroferrate(III)] complexes 2c and 2d. The catalytic activity of these novel
complexes has been evaluated in the cross-coupling reactions of alkyl halides with
Grignard reagents.
Ferrate complex
Imidazolidinium salt
Kochi cross-coupling reaction
ß 2014 Acad e´ mie des sciences. Published by Elsevier Masson SAS. All rights reserved.
1
. Introduction
Transition-metal-catalyzed cross-coupling reaction is
a valuable alternative as it is a cheap, abundant and
ecofriendly metal. Furthermore, during the last decade,
iron was intensively studied in catalytic transformations
[5]. In particular, iron complexes were used as catalysts in
synthetic chemistry for carbon–carbon bond formation
reactions [6], oxidation [7], and reduction reactions [8–10],
which offer attractive industrial possibilities in terms of
sustainable chemistry.
In the field of the extensively investigated transition-
metal-catalyzed cross-coupling carbon–carbon bond for-
mation [11], the Kumada–Corriu cross-coupling reaction of
aryl Grignard reagents with primary or secondary alkyl
halides was mainly dominated by palladium or nickel-
based catalysts [12]. In 1971, Kochi et al. first reported Fe-
catalyzed cross-coupling reactions of vinyl bromides with
alkyl Grignard reagents [13]. Since this pioneering con-
tribution, numerous reports on iron-catalyzed cross-
coupling have appeared in the literature [14], and it
became an obvious alternative to palladium-catalyzed
processes, even in total synthesis.
one of the most powerful tools in molecular synthesis [1],
and plays an important role in the synthesis of many drugs,
natural products, optical devices, and industrially impor-
tant starting materials [2]. In this area, nowadays,
palladium-catalyzed cross-coupling reactions represent
over 60% of the carbon-carbon bond formation reactions
used in medicinal chemistry [3]. However, the use of
transition metals such as palladium raises the issue of the
presence of residual contamination in the synthetic drugs
or intermediates that may affect either subsequent
chemical transformations or that meet government
requirements about maximum ppm level of residual metal
in medicinal compounds [4]. In this context, the investiga-
tion of new cross-coupling reactions catalyzed by more
benign metals is highly required. In this perspective, iron is
On another hand, N-heterocyclic carbenes (NHCs) are
certainly the class of ligands that has attracted the most
*
Corresponding author.
E-mail address: ismail.ozdemir@inonu.edu.tr ( I˙ . O¨ zdemir).
http://dx.doi.org/10.1016/j.crci.2014.03.015
631-0748/ß 2014 Acad e´ mie des sciences. Published by Elsevier Masson SAS. All rights reserved.
1
Please cite this article in press as: Demir S, et al. Imidazolidinium ferrate complexes: Synthesis and catalytic properties.
C. R. Chimie (2014), http://dx.doi.org/10.1016/j.crci.2014.03.015

G Model
CRAS2C-3929; No. of Pages 8
2
S. Demir et al. / C. R. Chimie xxx (2014) xxx–xxx
Scheme 1. Preparation of ferrate imidazolidinium complexes.
attention since Arduengo isolation of the first stable NHC
species in 1991 [15], following the pioneering report of
Wanzlick in 1968 [16]. They have become a unique class of
ligands due to their electronic and steric features: NHC
halide for 10–12 h at 80 8C in DMF [26]. Then, the reaction
of FeBr with one equivalent of imidazolidinium salts 1a
and 1b in ethanol was performed at 70 8C for 72 h. After
2
removal of the solvent under vacuum, recrystallization
ligands are generally known as strong
s
-donors and weak
3 2
from a CHCl /Et O mixture led to the ferrate complexes 2a
p
-acceptors and have tunable steric properties. They are
and 2b, which were isolated in 39 and 42% yields,
respectively, as red–orange crystals, which were air stable
both in the solid state and in solution (Scheme 1). Notably,
widely used in many areas from organocatalysis [17],
biochemistry and medicine [18] to transition-metal
coordination and catalysis [19]. Despite the first iron–
NHC complexes reported in the 1970s [20], the organo-
metallic chemistry of such complexes was less extensively
studied than that of the other noble transition metals, but
has been a growing field over the past decade [21,22]. Thus,
some NHC–iron catalytic systems have shown high
activities in homogeneous catalysis [23], and in particular
in cross-coupling reactions [24]. In the area of NHC–ferrate
complexes, imidazolium and benzimidazolium complexes
have been already described and were successfully used in
cross-coupling reactions [25].
In a continuation of our research on the organometallic
chemistry of iron with N-heterocyclic carbenes, we report
herein the synthesis and molecular structures of imida-
zolidinium ferrate complexes and the preliminary results
on catalytic cross-coupling Kochi reactions of alkyl halides
in the presence of Grignard reagents.
2 2 3
they can be dissolved in CH Cl , CHCl , and DMSO, leading
to a red orange solution, but they are insoluble in diethyl
ether and n-hexane.
When the reaction was performed starting from
Fe(OAc)
imidazolidinium salts 1b and 1c in acetonitrile at 60 8C for
48 h, the corresponding complexes (imidazolidinium) (-
Fe OCl ) 2c and 2d were isolated in 36 and 40% yield,
2
(2 equiv) as the iron precursor, with 1 equiv of
2
2
6
respectively, as white solids that are air stable both in the
solid state and in solution (Scheme 2).
All obtained complexes are paramagnetic and were
then characterized by elemental analysis and by crystal-
lographic analysis. The crystals of 2a, 2c and 2d, obtained
from a chloroform solution layered with diethyl ether
under air atmosphere, were suitable for X-ray single-
crystal diffraction analysis. The crystallography and
measurement data are shown in Figs. 1 and 2. The
molecular structures of the complexes, with the atom
numbering scheme, are shown in Figs. 1 and 2 (Tables 1
and 2).
2
. Results and discussion
2
.1. Synthesis and characterization of ferrate NHC complexes
As shown in Fig. 1, the iron center is coordinated by four
bromide atoms in a distorted tetrahedral geometry with
angles at iron in the range 107.53(7)–112.84(7)8, with a
mean value of 109.488 close to the ideal angle in
tetrahedral structure. The Fe–Br distances are between
First, 1,3-disubstituted imidazolidinium salts 1a–c
were prepared according to the reported procedure by
reaction of the N-substituted imidazoline with an alkyl
2 2 6
Scheme 2. Preparation of (imidazolidinium) (Fe OCl ) complexes.
Please cite this article in press as: Demir S, et al. Imidazolidinium ferrate complexes: Synthesis and catalytic properties.
C. R. Chimie (2014), http://dx.doi.org/10.1016/j.crci.2014.03.015

G Model
CRAS2C-3929; No. of Pages 8
S. Demir et al. / C. R. Chimie xxx (2014) xxx–xxx
3
´
Fig. 1. Molecular structure of 2a. Selected bond lengths ( A˚ ) and angles (deg): Fe(1)–Br(1) = 2.3192(18), Fe(1)–Br(2) = 2.2960(18), Br(4)–Fe(1) = 2.3079(16),
Br(3)–Fe(1) = 2.2760(19); Br(3)–Fe(1)–Br(2) = 109.14(8), Br(3)–Fe(1)–Br(4) = 107.90(7), Br(2)–Fe(1)–Br(4) = 112.84(7), Br(3)–Fe(1)–Br(1) = 111.39(8),
Br(2)–Fe(1)–Br(1) = 108.08(7), Br(4)–Fe(1)–Br(1) = 107.53(7).
Fig. 2. Molecular structures of 2c and 2d.
˚
˚
2
.2760(19) and 2.3192(18) A, with a mean value of 2.300 A,
two complex structures, the two aromatic rings for the
benzyl arm of the imidazolinium moiety are parallel,
which differs from the corresponding [bis(1,3-bibenzyli-
in accordance with those already reported [25d–f,27]. As
already described, for example, with palladium [28], or
nickel [29], complex 2a results in the combination of two
3 2
midazolium)][(FeCl ) O] [31].
À
ion pairs, the imidazolidinium one and FeBr
When using Fe(OAc)
4
.
2
as the iron salt source, the
2.2. Imidazolidinium ferrate-catalyzed cross-coupling
reaction with Grignard reagents
reaction led also to the complexes resulting in the
combination of ion pairs, two imidazolidinium moieties,
and one (FeCl
3
)
2
O ion.
The catalytic activity of anionic iron complexes 2a–2d
was then examined for the coupling reaction of a simple
aryl/alkyl chloride and bromide with Grignard reagents
(Table 3).
The cross-coupling reaction of phenyl magnesium
bromide with bromocyclohexane was chosen as a test
reaction because it is a common benchmark example of an
aryl Grignard with a secondary alkyl halide bearing a
In both structures 2c and 2d, the iron center of the
2
À
counter-ion is in a distorted tetrahedral geo-
(OFe
2
Cl
6
)
metry with angles at iron with mean values of 109.4738
and 109.4758, respectively, close to the ideal angle in
tetrahedral structure. Furthermore, bridging oxide O atom
displays a linear Fe–O–Fe with an angle of 1808 [30]. The
˚
Fe–Cl bond lengths range from 2.2211(14) A to 2.2326(14)
˚
˚
˚
A (mean value of 2.225 A) for 2c and from 2.2133(11) A to
hydrogen atom in b-position.
˚
˚
2
.2279(11) A (mean value of 2.219 A) for 2d. The Fe–O
In THF, the reaction proceeded in 10 minutes using
2.5 mol% of complex 2a at room temperature and provided
the cross-coupling product 3a in 66% yield, with 34% of
biphenyl 4a resulting from the homocoupling of the
˚
˚
distances are 1.7444(6) A and 1.7411(5) A for 2c and 2d,
respectively. Such values are in accordance with the
described (OFe
2
À
2
Cl
6
)
-type complexes. Notably, for these
Please cite this article in press as: Demir S, et al. Imidazolidinium ferrate complexes: Synthesis and catalytic properties.
C. R. Chimie (2014), http://dx.doi.org/10.1016/j.crci.2014.03.015

G Model
CRAS2C-3929; No. of Pages 8
4
S. Demir et al. / C. R. Chimie xxx (2014) xxx–xxx
Table 1
X-ray crystallographic data for complexes 2a, 2c, and 2d.
2a
2c
2d
Empirical formula
fw
C
18
H
29Br
4
FeN
2
O
C
50
H
66Cl
6
Fe
2
N
4
O
52 6 2 4
C H74Cl Fe N O
664.92
150(2)
0.71073
1063.47
150(2)
1095.55
150(2)
Temperature (K)
l
(Mo Ka) ( A˚ )
0.71073
0.71073
Cryst syst
Orthorhombic
Monoclinic
P2 /a
Monoclinic
P2 /a
Space group
Pcab
1
1
Unit cell dimension
a ( A˚ )
b ( A˚ )
c ( A˚ )
9.7617(3)
21.8705(7)
22.5179(8)
13.9025(13)
11.0340(12)
19.1209(19)
13.9317(8)
10.8833(6)
18.6985(12)
92.533(2)
2832.4(3)
2
b
(deg)
90
110.711
2743.6(5)
2
V ( A˚ 3
)
4807.4(3)
8
Z
D
calc (gÁcmÀ3
À1
)
1.837
7.287
2600
1.287
0.858
1112
1.285
m
(mm
)
0.833
F(000)
Crystal size (mm)
range (deg)
1152
0.3 Â 0.25 Â 0.03
3.55–27.48
32,053
0.16 Â 0.14 Â 0.07
2.92–27.48
18,783
0.25 Â 0.24 Â 0.02
2.93–27.48
23,902
u
Number of reflns collected
Number of reflns unique, Rint
5297, 0.0651
1.04
6076, 0.0768
1.018
6475, 0.0783
0.986
2
Goodness-of-fit on F
R
R
1
, wR
, wR
2
2
[I > 2
s
(I)]
0.0819, 0.2418
0.1499, 0.2926
0.064, 0.1531
0.1293, 0.1924
0.0553, 0.1244
0.126, 0.1554
1
(all data)
fw: formula weight; cryst syst: crystal system; reflns: reflections.
Grignard reagent (entry 1). When the reaction was
performed in diethyl ether under similar conditions, the
cross-coupling product 3a was obtained in 69% in
association with 31% of biphenyl 4a (entry 2). When
decreasing the catalytic loading to 1 mol%, 82% of
cyclohexylbenzene 3a can be obtained within 10 min at
r.t. and 85% within 10 min at 0 8C (entries 3 and 5). The
decrease in the loading to 0.5 mol had a deleterious effect
as only 42% of 3a is obtained with 58% of 4a. Under the
optimized conditions (1 mol% of complex, in diethyl ether
at room temperature for 10 min), complex 2b led to 73% of
reaction (entries 6–8). With p-tolylmagnesium bromide, to
reach full conversions, the reactions were performed at
room temperature for 3 h; with complexes 2a and 2b, the
cross-coupling compound 3b was obtained in 65 and 62%
yields, respectively, in mixture with the homocoupling bis-
p-tolyl derivative 4b (entries 9 and 10). By contrast,
complexes 2c and 2d led exclusively to the homocoupling
product 4b in 80 and 70% yields, respectively, which shows
that
m-oxido-bis[trichloroferrate(III)] complexes have a
different chemoselectivity (entries 11 and 12). Cahiez has
shown that alkyl Grignard reagents react with alkenyl
3
a and 27% of 4a, whereas complexes 2c and 2d gave no
3
halides in the presence of [Fe(acac) ] to give excellent
yields of the cross-coupling product when NMP is used as a
co-solvent [32]. Also, F u¨ rstner has described and demon-
strated the generality of the iron-catalyzed coupling
reactions with alkyl Grignard reagents with the use of
NMP as a co-solvent [33]. In this work, we described the
cross-coupling reaction between halides (alkyl or aryl) and
aryl Grignard reagents. We also tried the use of NMP as a
co-solvent and observed 41% cross-coupling product and
59% homocoupling product yields with p-tolylmagnesium
bromide and cyclohexylbromide with 2a catalyst. We
obtained better results without NMP as a co-solvent under
the same reaction conditions (entry 9).
Table 2
Selected bond lengths ( A˚ ) and angles (8) for 2c and 2d.
´
2c
2d
Fe(1)–O(1)
1.7444(6)
2.2217(13)
2.2326(14)
2.2211(14)
1.7444(6)
107.08(5)
111.15(5)
108.91(5)
110.90(5)
111.04(6)
107.76(5)
180
1.7411(5)
2.2133(11)
2.2165(11)
2.2279(11)
1.7411(5)
111.01(4)
107.35(4)
111.08(5)
110.81(4)
107.49(4)
109.11(4)
180.00(3)
Fe(1)–Cl(1)
Fe(1)–Cl(2)
Fe(1)–Cl(3)
O(1)–Fe(1a)
O(1)–Fe(1)–Cl(1)
O(1)–Fe(1)–Cl(2)
Cl(1)–Fe(1)–Cl(2)
O(1)–Fe(1)–Cl(3)
Cl(1)–Fe(1)–Cl(3)
Cl(2)–Fe(1)–Cl(3)
Fe(1a)–O(1)–Fe(1)
The reaction was then done with different alkyl and aryl
halides and phenylmagnesium bromide. With 2-cyclohex-
ylmethyl bromide, the cross-coupling compound 2-phe-
Please cite this article in press as: Demir S, et al. Imidazolidinium ferrate complexes: Synthesis and catalytic properties.
C. R. Chimie (2014), http://dx.doi.org/10.1016/j.crci.2014.03.015

G Model
CRAS2C-3929; No. of Pages 8
S. Demir et al. / C. R. Chimie xxx (2014) xxx–xxx
5
Table 3
a
Iron-catalyzed cross-coupling of aryl or alkyl halides and arylmagnesium bromide .
b
Entry
1
R-X
[Fe] (mol%)
Conditions
Yields (%)
3
4
2a (2.5)
THF, RT, 10 min
66
34
2
3
4
5
6
7
8
9
2a (2.5)
2a (1.0)
2a (0.5)
2a (1.0)
2b (1.0)
2c (1.0)
2d (1.0)
Et
2
Et
2
Et
2
Et
2
Et
2
Et
2
Et
2
Et
2
Et
2
Et
2
Et
2
O
O
O
O
O
O
O
O
O
O
O
69
82
42
85
73
—
31
18
58
15
27
—
—
—
c
2a (1.0)
65
62
—
35
38
80
71
c
1
1
1
0
1
2
2b (1.0)
c
2c (1.0)
c
2d (1.0)
—
1
3
2a (1.0)
Et
2
O, RT, 15 h
67
33
1
1
4
5
2b (1.0)
2c (1.0)
Et
Et
2
O
O
63
—
37
94
2
1
6
2a (1.0)
Et
2
O, RT, 15 h
5
95
1
1
7
8
2c (1.0)
2a (1.0)
Et
2
2
O, RT, 15 h
O, RT, 3 h
—
13
59
Et
41
1
2
9
0
2b (1.0)
2c (1.0)
Et
Et
2
O
O
37
—
63
9
2
2
1
2
2a (1.0)
2b (1.0)
Et
2
O, RT, 15 h
O, RT, 15 h
32
26
68
74
2
Et
2
a
2
Reaction conditions: all reactions were carried out in THF or Et O at room temperature with 1 mmol of aryl or alkyl halides, 1.5 mmol of PhMgBr (3 M in
Et
2
b
O) and iron catalyst (0.5–2.5 mol %).
Yields were determined by GC–MS.
c
Reaction with 1.5 mmol (1.5 equivalent) of p-tolylmagnesium bromide.
nyl-1-cyclohexylmethane 3b was obtained in 67 and 63%
yields using complexes 2a and 2b, respectively, but in
mixture with the biphenyl 4a, whereas complex 2c led
specifically to the homocoupling derivative 3a (entries 13–
were pre-catalysts for the cross-coupling reaction of alkyl
halides with aromatic Grignard reagents under mild
conditions at room temperature, whereas complexes 2c
and 2d led to homocoupling compounds.
1
5). By contrast, using aromatic halides such as p-anisyl
Further investigations of these ferrate complexes
containing N-heterocyclic carbene ligands are currently
evaluated in our laboratories.
bromide, p-anisyl iodide and p-tolyl bromide led to the
homocoupling compound 4a as the major product (entries
1
6–22). The most efficient catalyst for the cross-coupling
reaction is complex 2a, whereas complex 2c pertains to the
formation of the homocoupling product 4.
4. Experimental
All reactions were performed under an argon atmo-
sphere using standard Schlenk tubes and vacuum line
techniques. Solvents were distilled under argon over
3
. Conclusions
In summary, two tetrabromoferrate and two
m
-oxido-
2
sodium/benzophenone (THF and Et O) and degassed prior
bis[trichloroferrate] imidazolidinium complexes have
been synthesized, starting from the corresponding imida-
zolium bromides and iron salts. Notably, they have been
structurally characterized by X-ray analysis. The two
tetrabromoferrate imidazolidinium complexes 2a and 2b
to use. Chemicals and solvents were purchased from Sigma
Aldrich Co. (Dorset, UK). Imidazolidinium salts were
synthesized in our laboratory according to the literature
[26]. Elemental analyses were performed using a LECO
CHNS-932 elemental analyzer. Melting points were
Please cite this article in press as: Demir S, et al. Imidazolidinium ferrate complexes: Synthesis and catalytic properties.
C. R. Chimie (2014), http://dx.doi.org/10.1016/j.crci.2014.03.015

G Model
CRAS2C-3929; No. of Pages 8
6
S. Demir et al. / C. R. Chimie xxx (2014) xxx–xxx
measured in open capillary tubes with an Electrothermal-
200 melting point apparatus. All catalytic reactions were
monitored on a Agilent 6890 N GC system by GC-FID with a
HP-5 column of length 30 m, diameter 0.32 mm, and film
quenched with H
(3 Â 10 mL). The combined organic layer was dried over
anhydrous MgSO and evaporated under reduced pres-
2 2 2
O (5 mL) and extracted with CH Cl
9
4
sure. The crude material was purified by column
chromatography to afford the desired coupling product
thickness 0.25
mm. Column chromatography was per-
1
formed using silica gel 60 (70–230 mesh). Solvent ratios
are given as v/v.
in high purity. H NMR and GC–MS were consistent with
the known material.
4
.1. General experimental procedure for the preparation of
Acknowledgments
the anionic iron complexes
This work was supported financially by the Technolo-
4
.1.1. Synthesis of 2a and 2b complexes
A mixture of imidazolidinium salts (1 mmol) and FeBr
˙
gical and Scientific Research Council of Turkey (TUBITAK),
2
˙
¨ ¨
and the CNRS (France) [project 210T051] and the Inonu
University Research Fund (2013/170). CD and JBS are
grateful to the ‘‘Universit e´ de Rennes-1’’, ‘‘Rennes M e´ tro-
pole’’ and the French ‘‘Minist e` re de l’Enseignement
sup e´ rieur et de la Recherche’’ for support.
(
1 mmol) in ethanol (25 mL) was stirred at 70 8C for three
days. The solvent was removed under vacuum and the
crude product was crystallized from CHCl /Et O and
3
2
yielded reddish–purple crystals suitable for elemental
analyses and X-ray diffraction determination. NMR
spectra could not be recorded as it is a paramagnetic
compound.
References
[1] (a) A. de Meijere, F. Diederich (Eds.), Metal-Catalyzed Cross-Coupling
Reactions, second ed., Wiley-VCH, New York, 2004;
4
.1.1.1. Complex 2a. Yield after recrystallization: 259 mg
+
(b) N. Miyaura, in: N. Miyaura (Ed.), Cross-Coupling Reactions: A
Practical Guide in Topics in Current Chemistry, Vol. 219, Springer,
Berlin, 2002, p. 1159.
(39%), m.p.: 123–124 8C, m/z 289.18 [M ] calculated for
C
18
H
29
N
2
O. Anal. calcd for C18
29 2 4
H N OBr Fe: C, 32.52; H,
[2] J.-P. Corbet, G.R. Mignani, Chem. Rev. 106 (2006) 2651.
[3] S.D. Roughley, A.M. Jordan, J. Med. Chem. 54 (2011) 3451.
[4] C.E. Garrett, K. Prasad, Adv. Synth. Catal. 346 (2004) 889.
4
.40; N, 4.21, found: C, 32.60; H, 4.51; N, 4.25%.
4
.1.1.2. Complex 2b. Yield after recrystallization: 310 mg
[5] (a) C. Bolm, J. Legros, J. Le Paih, L. Zani, Chem. Rev. 104 (2004) 6217;
b) B. Plietker, in: B. Plietker (Ed.), ‘‘Iron Catalysis in Organic Chemis-
try’’, Wiley-VCH Verlag, Weinheim, 2008;
c) W.M. Czaplik, M. Mayer, J. Cvengros, A. Jacobi von Wangelin,
ChemSusChem 2 (2009) 396;
+
(
(
42%), m.p.: 171–172 8C, m/z 363.4 [M ] calculated for
. Anal. calcd for C25 Br Fe: C, 40.63; H, 4.77;
N, 3.79, found: C, 40.72; H, 4.71; N, 3.84%.
C
25
H
35
N
2
H
35
N
2
4
(
(
(
d) C.L. Sun, B.J. Li, Z.J. Shi, Chem. Rev. 111 (2011) 1293;
e) K. Gopalaiah, Chem. Rev. 113 (2013) 3248.
4.1.2. Synthesis of 2c and 2d complexes
A mixture of imidazolidinium salts (2 mmol) and
Selected examples
2
Fe(OAc) (1 mmol) in dry acetonitrile (25 mL) was stirred
at 60 8C for 2 days. The solvent was removed under vacuum
[6] (a) W.M. Czaplik, M. Mayer, S. Grupe, A. Jacobi von Wangelin, Pure
and the crude product was crystallized in the air from
Appl. Chem. 82 (2010) 1545;
(
(
b) A. F u¨ rstner, Angew. Chem. Int. Ed. 48 (2009) 1364;
3 2
CHCl /Et O and yielded yellow crystals suitable for
c) A. Leitner, in: B. Plietker (Ed.), In Iron Catalysis in Organic Chemis-
elemental analyses and X-ray diffraction determination.
NMR spectra could not be recorded as it is a paramagnetic
compound.
try, Wiley-VCH, Weinheim, Germany, 2008, p. 147;
(d) B.D. Sherry, A. F u¨ rstner, Acc. Chem. Res. 41 (2008) 1500;
(
e) A. F u¨ rstner, R. Martin, Chem. Lett. 34 (2005) 624;
(
f) A. F u¨ rstner, A. Leitner, M. M e´ ndez, H. Krause, J. Am. Chem. Soc. 124
(2002) 13856.
4
.1.2.1. Complex 2c. Yield after recrystallization: 384 mg
+
(36%), m.p.: 298–299 8C, m/z 363.3 [M ] calculated for
Selected examples
C
25
H
35
N
2
. Anal. calcd for C50
70 4 6 2
H N Cl Fe O: C, 56.25; H,
[
7] (a) D.H.R. Barton, M.J. Gastiger, W.B. Motherwell, J. Chem. Soc., Chem.
Commun. 1 (1983) 41;
6
.61; N, 5.25, found: C, 56.31; H, 6.67; N, 5.18%.
(b) M.S. Chen, M.C. White, Science 318 (2007) 783;
4
.1.2.2. Complex 2d. Yield after recrystallization: 438 mg
(c) L. Que, W.B. Tolman, Nature 455 (2008) 333.
+
(40%), m.p.: 285–286 8C, m/z 377.5 [M ] calculated for
Selected reviews
C
26
H
37
N
2
. Anal. calcd for C52
74 4 6 2
H N Cl Fe O: C, 57.01; H,
6
.81; N, 5.11, found: C, 57.13; H, 6.77; N, 5.20%.
[
8] (a) K. Junge, K. Schr o¨ der, M. Beller, Chem. Commun. 47 (2011) 4849;
(
(
b) M. Zhang, A. Zhang, Appl. Organometal. Chem. 24 (2010) 751;
c) B.A.F. Le Bailly, S.P. Thomas, RSC Adv. 1 (2011) 1435;
4.2. General method for Grignard reagents cross-coupling
with aryl/alkyl halides
(d) R.H. Morris, Chem. Soc. Rev. 38 (2009) 2282.
Selected recent examples
Under a nitrogen atmosphere and at room tempera-
ture, 1.0 mmol of aryl/alkyl halides, iron catalyst (0.5–
[9] (a) S. Fleischer, S. Zhou, K. Junge, M. Beller, Angew. Chem. Int. Ed 52
2
.5 mol %) and a solution of 1.5 mmol of phenylmagne-
sium bromide (3 M solution in Et O) or p-tolylmagnesium
bromide (1 M in THF) were added in THF or Et O (3 mL) as
(2013) 5120;
(b) S. Das, B. Wendt, K. M o¨ ller, K. Junge, M. Beller, Angew. Chem., Int.
Ed. 51 (2012) 1662;
2
2
(
(
c) S. Das, Y. Li, K. Junge, M. Beller, Chem. Commun. 48 (2012) 10742;
d) A.M. Tondreau, C.C. Holilla Atienza, K.J. Weller, S.A. Nye, K.M. Lewis,
the solvent. The mixture was stirred at room temperature
or 60 8C for 10 min–48 h. The reaction mixture was
J.G.P. Delis, P.J. Chirik, Angew. Chem. Int. Ed. 335 (2012) 567;
Please cite this article in press as: Demir S, et al. Imidazolidinium ferrate complexes: Synthesis and catalytic properties.
C. R. Chimie (2014), http://dx.doi.org/10.1016/j.crci.2014.03.015

G Model
CRAS2C-3929; No. of Pages 8
S. Demir et al. / C. R. Chimie xxx (2014) xxx–xxx
7
(
(
(
(
e) J. Yang, T.D. Tilley, Science 49 (2010) 10186;
f) T. Inagaki, A. Ito, J.-I. Ito, H. Nishiyama, Angew. Chem. Int. Ed. 49
2010) 9384;
(b) E. Peris, R.H. Crabtree, Coord. Chem. Rev. 248 (2004) 2239;
(c) C.M. Crudden, D.P. Allen, Coord. Chem. Rev. 248 (2004) 2247;
(d) D. Pugh, A.A. Danopoulos, Coord. Chem. Rev. 251 (2007) 610;
(e) J.A. Mata, M. Poyatos, E. Peris, Coord. Chem. Rev. 251 (2007) 841;
(f) S. Diez-Gonzalez, N. Marion, S.P. Nolan, Chem. Rev. 109 (2009)
3612;
(g) F.E. Hahn, M.C. Jahnke, Angew. Chem. Int. Ed. 47 (2008) 3122;
(h) H.D. Velazquez, F. Verpoort, Chem. Soc. Rev. 41 (2012) 7032;
(i) L.-A. Schaper, S.J. Hock, W.A. Herrmann, F.E. Kuhn, Angew. Chem.
g) G. Wienh o¨ fer, F.A. Westerhaus, R.V. Jagadeesh, K. Junge, H. Junge, M.
Beller, Chem. Commun. 48 (2012) 4827;
h) R.P. Yu, J.M. Darmon, J.M. Hoyt, G.W. Margulieux, Z.R. Turner, P.J.
Chirik, ACS Catal. 2 (2012) 1760;
i) R. Langer, Y. Diskin-Posner, G. Leitus, L.J.W. Shimon, Y. Ben-David, D.
Milstein, Angew. Chem. Int. Ed. 50 (2011) 9948;
(
(
(
(
j) C.P. Casey, H. Guan, J. Am. Chem. Soc. 131 (2009) 2499;
k) C. Sui-Seng, F. Freutel, A.J. Lough, R.H. Morris, Angew. Chem. Int. Ed.
Int. Ed. 52 (2013) 270.
[20] (a) K. O¨ fele, C.G. Kreiter, Chem. Ber. 105 (1972) 529;
4
9 (2008) 940.
(b) G. Huttner, W. Gartzke, Chem. Ber. 105 (1972) 2714;
(c) M.F. Lappert, J.J. MacQuitty, P.L. Pye, J. Chem. Soc., Chem. Commun.
12 (1977) 411.
[
10] (a) D. B e´ zier, G.T. Venkanna, L.C. Misal Castro, J. Zheng, T. Roisnel, J.-B.
Sortais, C. Darcel, Adv. Synth. Catal. 354 (2012) 1879;
(
b) D. B e´ zier, F. Jiang, T. Roisnel, J.-B. Sortais, C. Darcel, Eur. J. Inorg.
Chem. 9 (2012) 1333;
c) J. Zheng, L.C. Misal Castro, T. Roisnel, C. Darcel, J.-B. Sortais, Inorg.
Chim. Acta 380 (2012) 301;
d) L.C. Misal Castro, J.-B. Sortais, C. Darcel, Chem. Commun. 48 (2012)
51;
(
For a recent review, see
(
1
[
[
21] M.J. Ingleson, R.A. Layfield, Chem. Commun. 48 (2012) 3579.
22] (a) P. Buchgraber, L. Toupet, V. Guerchais, Organometallics 22 (2003)
(
(
(
e) D. B e´ zier, G.T. Venkanna, J.-B. Sortais, C. Darcel, ChemCatChem 3
2011) 1747;
f) L.C. Misal Castro, D. B e´ zier, J.-B. Sortais, C. Darcel, Adv. Synth. Catal.
5
(
144;
b) A.A. Danopoulos, N. Tsoureas, J.A. Wright, M.E. Light, Organome-
tallics 23 (2004) 166;
c) I. Nieto, F. Cervantes-Lee, J.M. Smith, Chem. Commun. 30 (2005)
811;
(d) A.A. Danopoulos, J.A. Wright, W.B. Motherwell, Chem. Commun. 6
2005) 784;
3
53 (2011) 1279.
(
3
Representative reviews
(
[
11] (a) J. Hassan, M. Sevignon, C. Gozzi, E. Schulz, M. Lemaire, Chem. Rev.
02 (2002) 1359;
(e) L. Mercs, G. Labat, A. Neels, A. Ehlers, M. Albrecht, Organometallics
25 (2006) 5648;
1
(
(
(
b) E.A.B. Kantchev, C.J. O’Brien, M.G. Organ, Angew. Chem. Int. Ed. 46
2007) 2768;
c) A.C. Hillier, G.A. Grasa, M.S. Viciu, H.M. Lee, C.L. Yang, S.P. Nolan, J.
(f) S.A. Llewellyn, M.L.H. Green, J.C. Green, A.R. Cowley, Dalton Trans.
21 (2006) 2535;
(g) Y.S. Wang, H.M. Sun, X.P. Tao, Q. Shen, Y. Zhang, Chin. Sci. Bull. 52
(2007) 3193;
(h) L. Mercs, A. Neels, M. Albrecht, Dalton Trans. 41 (2008) 5570;
(i) V. C e´ sar, N. Lugan, G. Lavigne, J. Am. Chem. Soc. 130 (2008) 11286;
Organomet. Chem. 653 (2002) 69;
d) C.C.C. Johansson Seechurn, M.O. Kitching, T.J. Colacot, V. Snieckus,
Angew. Chem. Int. Ed. 51 (2012) 5062.
(
(j) Y. Ohkiv, T. Hatanaka, K. Tatsumi, J. Am. Chem. Soc. 130 (2008)
1
(
7174;
Selected examples
k) O. Kaufhold, F.E. Hahn, T. Pape, A. Hepp, J. Organomet. Chem. 693
2008) 3435;
(l) J.J. Scepaniak, M.D. Fulton, R.P. Bontchev, E.N. Duesler, M.L. Kirk, J.M.
Smith, J. Am. Chem. Soc. 130 (2008) 10515;
(m) A.A. Danopoulos, D. Pugh, H. Smith, J. Saßmannshausen, Chem.
Eur. J. 15 (2009) 5491;
(n) D. Pugh, N.J. Wells, D.J. Evans, A.A. Danopoulos, Dalton Trans. 35
(2009) 7189;
(
[
12] (a) J. Huang, S.P. Nolan, J. Am. Chem. Soc. 121 (1999) 9889;
b) J. Terao, H. Watanabe, A. Ikumi, H. Kuniyasu, N. Kambe, J. Am.
Chem. Soc. 124 (2002) 4222;
(
(
(
(
(
c) L. Ackermann, A.R. Kapdi, C. Schulzke, Org. Lett. 12 (2010) 2298;
d) R. Ghosh, A. Sarkar, J. Org. Chem. 75 (2010) 8283;
e) P. Knochel, T. Thaler, C. Diene, Isr. J. Chem. 50 (2010) 547;
f) N. Liu, Z.-X. Wang, J. Org. Chem. 76 (2011) 10031.
(o) L. Mercs, H. Stoeckli-Evans, M. Albrecht, Dalton Trans. 35 (2009)
7168;
[
13] (a) M. Tamura, J.K. Kochi, J. Am. Chem. Soc. 93 (1971) 1487;
(
(
(
(
(
(
(
b) M. Tamura, J.K. Kochi, Synthesis (1971) 303;
(p) C.-H. Hsieh, M.Y. Darensbourg, J. Am. Chem. Soc. 132 (2010) 14118;
(q) A. Flores-Figueroa, T. Pape, J.J. Weigand, F.E. Hahn, Eur. J. Inorg.
Chem. 19 (2010) 2907;
(r) S. Zlatogorsky, C.A. Muryn, F. Tuna, D.J. Evans, M.J. Ingleson, Orga-
nometallics 30 (2011) 4974;
c) M. Tamura, J.K. Kochi, J. Organomet. Chem. 31 (1971) 289;
d) M. Tamura, J.K. Kochi, Bull. Chem. Soc. Jpn. 44 (1971) 3063;
e) J.K. Kochi, Acc. Chem. Res. 7 (1974) 351;
f) S.M. Neumann, J.K. Kochi, J. Org. Chem. 40 (1975) 599;
g) R.S. Smith, J.K. Kochi, J. Org. Chem. 41 (1976) 502;
h) J.K. Kochi, J. Organomet. Chem. 653 (2002) 11.
(s) J.M. Smith, J.R. Long, Inorg. Chem. 49 (2010) 11223;
(t) V.V.K.M. Kandepi, J.M.S. Cardoso, E. Peris, B. Royo, Organometallics
2
9 (2010) 2777;
u) R.A. Layfield, J.J.W. McDouall, M. Scheer, C. Schwarzmaier, F. Tuna,
Chem. Commun. 47 (2011) 10623;
(
For recent reviews of iron-catalyzed cross-coupling using
Grignard reagents, see
(
(
(
(
(
v) L. Xiang, J. Xiao, L. Deng, Organometallics 10 (2011) 2018;
w) J.A. Przyojski, H.D. Arman, Z.J. Tonzetich, Organometallics 31
2012) 3264;
x) S. Zlatogorsky, M.J. Ingleson, Dalton Trans. 41 (2012) 2685;
y) A.A. Danopoulos, P. Braunstein, M. Wesolek, K.Y. Monakhov, P.
[
14] (a) A. F u¨ rstner, A. Leitner, M. M e´ ndez, H. Krause, J. Am. Chem. Soc. 124
(
(
(
(
2002) 13856;
b) A. F u¨ rstner, R. Martin, Chem. Lett. 34 (2005) 624;
c) B.D. Sherry, A. F u¨ rstner, Acc. Chem. Res. 41 (2008) 1500;
d) W.M. Czaplik, M. Mayer, S. Grupe, A. Jacobi von Wangelin, Pure
Rabu, V. Robert, Organometallics 31 (2012) 4102;
z) T. Hashimoto, S. Urban, R. Hoshino, Y. Ohki, K. Tatsumi, F. Glorius,
Organometallics 31 (2012) 4474.
(
Appl. Chem. 82 (2010) 1545.
[15] A.J. Arduengo, R.L. Harlow, M. Kline, J. Am. Chem. Soc. 113 (1991) 361.
[
16] H.W. Wanzlick, H.J. Sch o¨ nherr, Angew. Chem. Int. Ed. Eng. 7 (1968) 141.
[17] (a) N. Marion, S. Diez-Gonzalez, S.P. Nolan, Angew. Chem. Int. Ed. 46
For a review
(
(
(
(
2007) 2988;
b) D. Enders, O. Niemeier, A. Henseler, Chem. Rev. 107 (2007) 5606;
c) V. Nair, S. Vellelath, B.P. Babu, Chem. Soc. Rev. 37 (2008) 2691;
d) A.T. Biju, N. Kuhl, F. Glorius, Acc. Chem. Res. 44 (2011) 1182.
[23] D. B e´ zier, J.-B. Sortais, C. Darcel, Adv. Synth. Catal. 355 (2013) 19.
[24] (a) R.B. Bedford, M. Betham, D.W. Bruce, A.A. Danopoulos, R.M. Frost,
M. Hird, J. Org. Chem. 71 (2006) 1104;
[
18] (a) G. Gasser, I. Ott, N. Metzler-Nolte, J. Med. Chem. 54 (2011) 3;
b) A. Kascatan-Nebioglu, M.J. Panzner, C.A. Tessier, C.L. Cannon, W.J.
Youngs, Coord. Chem. Rev. 251 (2007) 884;
c) M.-L. Teyssot, A.-S. Jarrousse, M. Manin, A. Chevry, S. Roche, F.
(
(b) S.K. Ghorai, M. Jin, T. Hatakeyama, M. Nakamura, Org. Lett. 14
(2012) 1066;
(c) T. Hatakeyama, M. Nakamura, J. Am. Chem. Soc 129 (2007) 9844;
(d) T. Hatakeyama, S. Hashimoto, K. Ishizuka, M. Nakamura, J. Am.
Chem. Soc 131 (2009) 11949;
(
Norre, C. Beaudoin, L. Morel, D. Boyer, R. Mahiou, A. Gautier, Dalton
Trans. 35 (2009) 6894.
[
19] (a) F.E. Hahn, L. Wittenbecher, D. Le Van, R. Frohlich, Angew. Chem. Int.
Ed. 39 (2000) 541;
(e) L. Xiang, J. Xiao, L. Deng, Organometallics 30 (2011) 2018;
(f) A.L. Silberstein, S.D. Ramgren, N.K. Garg, Org. Lett. 14 (2012) 3796.
Please cite this article in press as: Demir S, et al. Imidazolidinium ferrate complexes: Synthesis and catalytic properties.
C. R. Chimie (2014), http://dx.doi.org/10.1016/j.crci.2014.03.015

G Model
CRAS2C-3929; No. of Pages 8
8
S. Demir et al. / C. R. Chimie xxx (2014) xxx–xxx
For Imidazolium ferrate complexes, see
As an example with palladium
[
25] (a) K. Bica, P. Gaertner, Org. Lett. 8 (2006) 733;
b) H.H. Gao, C.H. Yan, X.P. Tao, Y. Xia, H.M. Sun, Q. Shen, Y. Zhang,
Organometallics 29 (2010) 4189;
[28] X. Yang, Z. Fei, T.J. Geldbach, A.D. Phillips, C.G. Hartinger, Y. Li, P.J.
Dyson, Organometallics 27 (2008) 3971.
(
(
(
(
c) C.H. Yan, L.L. Wang, H.H. Gao, H.M. Sun, Q. Shen, Chin. Sci. Bull. 57
2012) 1953;
d) H.N. Deng, Y.L. Xing, C.L. Xia, H.M. Sun, Q. Shen, Y. Zhang, Dalton
As an example with nickel, see
Trans. 41 (2012) 11597;
e) Y. Xia, C.H. Yan, Z. Li, H.H. Gao, H.M. Sun, Q. Shen, Y. Zhang, Chin. Sci.
Bull. 58 (2013) 493;
f) For benzimidazolium ferrate complexes, see C.-L. Xi, C.-F. Xie, Y.-F.
[29] P.B. Hitchcock, K.R. Seddon, T. Welton, J. Chem. Soc., Dalton Trans. 2
(1993) 2639.
[30] (a) J.-C. Chang, W.-Y. Ho, I.-W. Sun, Y.-K. Chou, H.-H. Hsieh, T.-Y. Wu, S.-
S. Liang, Polyhedron 29 (2010) 2976;
(
(
Wu, H.-M. Sun, Q. Shen, Y. Zhang, Org. Biomol. Chem. 11 (2013) 8135.
26] S. Demir, I˙ . O¨ zdemir, B. C¸ etinkaya, J. Organomet. Chem. 694 (2009)
(b) G. Haselhorst, K. Wieghardt, S. Keller, B. Schrader, Inorg. Chem. 32
(1993) 520.
[
[
4
025.
[31] E.M. Mutambi, C.J. Adams, A.G. Orpen, Acta Cryst. E66 (2010) m846.
[32] (a) G. Cahiez, H. Avedissian, Synthesis 8 (1998) 1199;
(b) G. Cahiez, O. Gager, J. Buendia, C. Patinote, Chem. Eur. J. 18 (2012)
5860.
[33] (a) A. F u¨ rstner, A. Leitner, M. M e´ ndez, H. Krause, J. Am. Chem. Soc. 124
(2002) 13856;
27] (a) C. Jia, S.-X. Liu, C. Ambrus, G. Labat, A. Neels, S. Decurtins, Polyhe-
dron 25 (2006) 1613;
(
b) A. Abedi, N. Safari, V. Amani, H.R. Khavasi, Dalton Trans. 40 (2011)
877;
c) T. B a¨ cker, O. Breunig, M. Valldor, K. Merz, V. Vasylyeva, A.-V.
Mudring, Cryst. Growth Des. 11 (2011) 2564.
6
(
(b) A. F u¨ rstner, A. Leitner, Angew. Chem. Int. Ed. 41 (2002) 609.
Please cite this article in press as: Demir S, et al. Imidazolidinium ferrate complexes: Synthesis and catalytic properties.
C. R. Chimie (2014), http://dx.doi.org/10.1016/j.crci.2014.03.015