New biionic transition metal complexes based on the salen ligands: Synthesis and application as synthons in the preparation of chiral homo- and heterobimetallic systems

Article abstract of DOI:10.1007/s11172-011-0241-5

A new approach was used for the development of chiral homo- and heterobimetallic systems resulting in the preparation of four original bimetallic systems, two of which were studied by X-ray diffraction.

Full text of DOI:10.1007/s11172-011-0241-5

Russian Chemical Bulletin, International Edition, Vol. 60, No. 8, pp. 1612—1619, August, 2011
1612
New biionic transition metal complexes based
on the salen ligands: synthesis and application as synthons
in the preparation of chiral homoꢀ and heterobimetallic systems
P. M. Bolotov, V. N. Khrustalev, and V. I. Maleev
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences,
28 ul. Vavilova, 119991 Moscow, Russian Federation.
Fax: +7 (499) 135 5085. Eꢀmail: vim@ineos.ac.ru
A new approach was used for the development of chiral homoꢀ and heterobimetallic sysꢀ
tems resulting in the preparation of four original bimetallic systems, two of which were studied
by Xꢀray diffraction.
Key words: chiral reactants, bimetallic complexes, binuclear catalytic systems, salen comꢀ
plexes, biionic systems.
Studies in the field of asymmetric metal complex caꢀ
talysis have been conducted already for quite a while, and
various efficient chiral catalytic systems have been develꢀ
oped since then.1—4 It was found that the best results (the
yields >99%, the ee up to 99%) are shown by binuclear
catalytic systems, in which the metal ions are fixed in
space with respect to each other,5—7 and such a fixation of
metals can be due to either the covalent bond system,8—12 or
noncovalent13 interactions. In the overwhelming majority
of cases, such binuclear catalytic systems are homobiꢀ
metallic. In the first place, this is because the polydentate
ligands capable of retaining two (or more) metal ions at
the fixed distance by the covalent bond system are used for
their synthesis, but such an approach does not guarantee
obtaining heterobimetallic systems. As of this moment,
only a limited number of methods for the synthesis of
heterobimetallic systems are known;14—18 however, most
of them cannot be virtually used for the synthesis of sysꢀ
tems based on two different transition metals.
We have chosen complexes of chiral tetradentate
ligands, which are the Schiff bases of (R,R)ꢀdiaminocycloꢀ
hexane with substituted salicylaldehydes (salens) bearing
charged functional groups (B), as the first model systems.
Taking this into account, we set us a purpose to develop
a simple method for the synthesis of bimetallic systems,
which would have allowed us to equally easily obtain both
the homoꢀ and heterobimetallic systems.
Our approach is based on the idea of mutual fixation of
two separate molecules of metal complexes with respect to
each other by electrostatic interaction. Initially, complexes
of different metals are prepared separately, and only then they
are used to form bimetallic homoꢀ or heterobimetallic
systems. The authors of the work19 used an approach, which
has something in common with ours, but differing in the fact
that a chiral organic anion of the BINOL phosphoric acid
derivative was a counter ion at the achiral manganese comꢀ
plex in the "ionꢀpair" catalyst A developed by the authors.9
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1587—1593, August, 2011.
1066ꢀ5285/11/6008ꢀ1612 © 2011 Springer Science+Business Media, Inc.

Chiral homoꢀ and heterobimetallic systems
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 8, August, 2011
1613
Sulfo groups were chosen as the anionic and trimethylꢀ
ammonium groups as the cationic groups. The choice of
such a system was stipulated by the fact that salenꢀbased
catalysts in most cases display excellent results in the enanꢀ
tioselective formation of C—C and C—N bonds (see
Refs 20 and 21).
the starting compound. Such a Schiff base (1) has been
described earlier,22 but we modified this method using
(1R,2R)ꢀ1,2ꢀdiaminocyclohexane as a free base, as it is
shown in Scheme 1, rather than its salt with (R,R)ꢀtartaric
acid, as in the original22 work.
This method seems to be more simple and convenient,
since it does not require additional purification of ligand 1
from the tartrate impurities.
Results and Discussion
Further, we developed a procedure for the synthesis of
the second ligand 5 required for the study (Scheme 2).
It was found that direct reduction of 3ꢀtertꢀbutylꢀ5ꢀnitroꢀ
salicylaldehyde with hydrogen with simultaneous reducꢀ
tive methylation of the amino group with formaldehyde
leads to the key intermediate product, viz., 3ꢀtertꢀbutylꢀ5ꢀ
dimethylaminosalicylaldehyde; however, it has proved
unstable, and we rejected this approach. That is why we
have chosen the method using a salicylaldehyde triacetyl
derivative, viz., 2ꢀ(diacetoxymethyl)ꢀ6ꢀtertꢀbutylꢀ4ꢀnitroꢀ
phenyl acetate (2),23 as the starting compound. Compound 2
was also reduced with hydrogen with simultaneous methꢀ
ylation, that allowed us to obtain 2ꢀ(diacetoxymethyl)ꢀ6ꢀ
tertꢀbutylꢀ4ꢀ(dimethylamino)phenyl acetate (3) stable
even during prolonged storage. The reaction of compound 3
with (1R,2R)ꢀ1,2ꢀdiaminocyclohexane (R,R)ꢀtartrate
in aqueous ethanol in the presence of potash led
to (1R,2R)ꢀ1,2ꢀbisꢀ{[3ꢀtertꢀbutylꢀ5ꢀ(dimethylamino)ꢀ2ꢀ
hydroxyphenyl]methyleneamino}cyclohexane (4). The
reaction of methyl iodide with compound 4 in MeCN
afforded the target compound 5. Note that, despite seemꢀ
Synthesis of ligands with anionic groups involves the
use of 3ꢀtertꢀbutylꢀ5ꢀsulfosalicylaldehyde disodium salt as
Scheme 1
Scheme 2
Reaction conditions: i. (MeCO)2O, H2SO4; ii. HCHO, H2, Pd/H, EtOH; iii. (1R,2R)ꢀ1,2ꢀdiaminocyclohexane (R,R)ꢀtartrate, K2CO3,
EtOH, H2O; iv. MeI, MeCN.

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Bolotov et al.
ing feasibility and simplicity of the synthesis, compounds
2—5 were obtained for the first time.
Thus obtained ligands 1 and 5 were converted to the
corresponding complexes upon the action of copper(II)
and nickel(II) acetates in methanol (Scheme 3).
For the synthesis of binuclear metalꢀcontaining sysꢀ
tems, solutions of complexes 6 and 7 in methanol were
mixed in pairs in equimolar ratios, which led to the formaꢀ
tion of compounds 8—11 as precipitates (Scheme 4).
Elemental analysis of complexes 8—11 showed that
these compounds contain no iodine and in complexes 9
and 10 the ratio of metals Cu : Ni = 1 : 1. Since such
compounds were obtained for the first time, it was of inꢀ
terest to study their structures. Single crystals of comꢀ
plexes 9 and 10 were grown from methanol solutions.
The structures of the synthesized compounds are given in
Figs 1 and 2.
Scheme 3
The Xꢀray diffraction study showed that the planes of
the complex "halves" are at a distance of about 3.6 Å with
respect to each other, whereas the distance between the
metal atoms is 5 Å. In both complexes (9 and 10), one
methanol molecule is coordinated to the Cu atom.
In conclusion, we developed a new method for the
design of bimetallic salen systems, which allows the synꢀ
thesis of both homoꢀ and heterobinuclear catalytic sysꢀ
tems with equal simplicity. At the present time, we conꢀ
duct studies on catalytic activity and stereodifferentiating
ability of the obtained chiral binuclear metal complex sysꢀ
tems in the reactions with the C—C bond formation.
Experimental
1: R´ = Na, R = SO3Na
Comꢀ
pound
6a
6b
7a
R
M
–
5: R´ = H, R = N+Me3I
1
The H and 13C NMR spectra were recorded on a Bruker
SO3Na
SO3Na
N+Me3I
N+Me3I
Ni
Cu
Ni
AVANCE 300 spectrometer (300 MHz and 75.5 MHz, respecꢀ
tively) using residual signals for the undeuterated solvent as an
internal standard (1H NMR). Optical rotation was measured on
a Perkin—Elmer 241 polarimeter in a 5ꢀcm thermostated cell at
25 °C. Elemental analysis for the compounds obtained was perꢀ
formed in the Elemental Analysis Laboratory of the A. N. Nesꢀ
meyanov Institute of Organoelement Compounds of the Russian
Academy of Sciences. The C, H, and N contents were deterꢀ
mined on a Carlo Erba 1106 instrument, the S content was deꢀ
–
–
7b
Cu
Complexes 6 and 7 are colored powders, poorly soluꢀ
ble in both water and most organic solvents, except methꢀ
anol. These complexes were obtained for the first time and
characterized by elemental analysis, UV spectroscopy, and
NMR (for compounds 6a and 7a).
Scheme 4
M1 = Ni (8, 9), M2 = Ni (8), Cu (9)
2 = Cu (10, 11), M1 = Ni (10), Cu (11)
M

Chiral homoꢀ and heterobimetallic systems
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 8, August, 2011
1615
N(10)
Cu(2)
N(8)
N(9)
N(7)
S(4)
N(12)
N(11)
Ni(2)
S(3)
Fig. 1. The structure of complex 9. Hydrogen atoms and the solvent molecules are not shown.
S(1)
Cu(1)
N(2)
N(1)
S(2)
N(5)
N(3)
N(4)
Ni(1)
N(6)
Fig. 2. The structure of complex 10. Hydrogen atoms and the solvent molecules are not shown.
termined by the Schöniger method, the Cu and Ni contents,
by Xꢀray fluorescence analysis on a VRA 30 instrument. Elecꢀ
tronic absorption spectra were recorded on a Specord Mꢀ40 specꢀ
trometer (Carl Zeiss, Jena). All the starting reactants (Aldrich or
Acros) were used without additional purification. (R,R)ꢀDiꢀ
aminocyclohexane was obtained by resolution of racemic 1,2ꢀdiꢀ
aminocyclohexane through the formation of diastereomeric salt
with (1R,2R)ꢀtartaric acid24 and subsequent liberation of the
free base, i.e., (R,R)ꢀdiaminocyclohexane, using the known proꢀ
cedure.25 According to the GLC data, the enantiomeric purity
of (1R,2R)ꢀcyclohexanediamine in the formed salt is 99%
(a 25 m×0.23 mm ID quartz capillary column, 12 μm DPꢀTFA-

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Bolotov et al.
βꢀCD, Tcol = 140°C, N2 carrier gas, 1.8 atm, retention time
11.2 min). 3ꢀtertꢀButylꢀ5ꢀsulfosalicylaldehyde disodium salt was
obtained using the known procedure.22 3ꢀtertꢀButylꢀ5ꢀnitroꢀ
salicylaldehyde was obtained according to the standard proceꢀ
dure by nitration of 3ꢀtertꢀbutylsalicylaldehyde in acetic acid.26
Properties of the starting compounds obtained by these proceꢀ
dures completely corresponded to the literature data.
with occupancies of 0.6 : 0.4 and one has partial occupancy
of 0.5) were refined with anisotropic displacement parameters for
nonhydrogen atoms. Methanol and water solvent molecules in
the crystal of compound 9 are considerably disordered and it was
impossible to correctly refine their positions in the framework of
the experiment performed. Therefore, the contribution of these
molecules to the total scattering from the crystal of compound 9
was removed using the SQUEEZE program implemented in the
PLATON98 program package.28 The total amount of solvent
molecules in the crystal of compound 9 was determined based on
the data from the SQUEEZE program, which showed that the
number of electrons in the free volume of its unit cell is equal to
158, as well as based on the isostructurality of crystals of comꢀ
pounds 9 and 10 (see Table 1). The hydrogen atoms in methanol
and water solvent molecules in compound 10 were located in the
difference Fourier maps and refined with fixed positional and
thermal parameters. The other hydrogen atoms in both comꢀ
pounds were positioned geometrically and refined isotropically
with the fixed positional (the riding model) and thermal (Uiso(H) =
= 1.5Ueq(C) for the CH3 groups and Uiso(H) = 1.2Ueq(C) for all
other groups) parameters. The absolute structures of compounds
9•6CH3OH•5H2O and 10•5.75CH3OH•4.75H2O were
determined by the refinement of the Flack parameter (see Table 1).
All the calculations were performed using the SHELXTL program
package.29 The tables of the atomic coordinates, bond distances,
bond and torsion angles, and anisotropic temperature parameters
The unit cell parameters and intensities of reflections for the
crystals of compounds 9 and 10 were measured on a Bruker
SMART APEX II CCD automatic diffractometer (T = 100 K,
λMoꢀKα radiation, graphite monochromator, ϕꢀ and ωꢀscan
technique). The absorption correction was applied using the
SADABS program.27 The basic crystallographic data are given in
Table 1. The structures of the compounds were solved by direct
methods and refined by the fullꢀmatrix least squares method with
anisotropic displacement parameters for nonhydrogen atoms.
Crystals of both compounds contain two independent formula units
per asymmetric unit. Two of four sulfo groups in different anions of
compound 9 and all four sulfo groups in the anions of compound 10
are disordered over two positions related by the rotation around
the C—S single bond with occupancies of 0.5 : 0.5, 0.5 : 0.5, 0.7 : 0.3,
0.5 : 0.5, 0.7 : 0.3, and 0.5 : 0.5, respectively. Crystals of both
compounds contain methanol and water solvent molecules. In
the crystal of compound 10, twelve methanol solvent molecules
(one of which has partial occupancy of 0.5) and ten water solꢀ
vent molecules (one of which is disordered over two positions
Table 1. Basic crystallographic data and structure refinement statistics for compounds 9•6CH3OH•5H2O and
10•5.75CH3OH•4.75H2O
Compound
9•6CH3OH•5H2O
10•5.75CH3OH•4.75H2O
Molecular formula
Crystal size, mm
Molecular weight
T/K
C69H124N6O22S2NiCu
0.02×0.25×0.25
1576.11
100
C68.75H122.5N6O21.5S2NiCu
0.15×0.18×0.21
1563.60
100
Crystal system
Space group
a/Å
b/Å
c/Å
α/deg
β/deg
Triclinic
Triclinic
P–1
P–1
8.947(6)
15.316(11)
29.58(2)
77.166(16)
84.593(16)
88.734(16)
3935(5)
2
8.6649(6)
15.4052(10)
30.615(2)
78.719(2)
87.894(2)
88.695(2)
4004.5(5)
2
γ/deg
V/Å3
Z
dcalc/g cm–3
F(000)
1.330
1690
0.636
1.297
1676
0.624
μ/mm–1
2θmax/deg
50
53
Number of reflections
measured
33911
27200
13820
1285
0.0771
40021
32249
19512
1720
0.0718
independent
with I > 2σ(I)
Number of refinement parameters
R1 (I > 2σ(I))
wR2 (all reflections)
GOOF
0.2033
0.851
0.1846
1.003
Flack parameter
Tmin/Tmax
0.036(15)
0.857/0.987
0.028(14)
0.880/0.912

Chiral homoꢀ and heterobimetallic systems
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 8, August, 2011
1617
for compounds 9•6CH3OH•5H2O and 10•5.75CH3OH•4.75H2O
were deposited with the Cambrige Structural Database.
tered, and washed with water and a small amount of ethanol to
y
i
e
l
d
(1R,2R)ꢀCyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenylꢀ3ꢀtertꢀbutylꢀ
2ꢀhydroxybenzoꢀ5ꢀsulfonic acid) disodium salt (1). (1R,2R)ꢀ1,2ꢀ
Diaminocyclohexane (151 mg, 1.32 mmol) was added to a soluꢀ
tion of 3ꢀtertꢀbutylꢀ5ꢀsulfosalicylaldehyde disodium salt (800 mg,
2.65 mmol) in methanol (5 mL). The mixture was refluxed for
6 h, then the solvent was evaporated on a rotary evaporator, and
the residue that was obtained was dried using a vacuum oil pump
to yield a dark yellow product (870 mg, 96%), which was used
a yellow product (527 mg, 37%). M.p. 110—112 °C, [α]D25 –308
1
(c 0.01 MeOH). H NMR (300 MHz, CDCl3), δ: 8.25 (s, 2 H,
CHN); 6.89 (d, 2 H, Ar, J = 2.9 Hz); 6.43 (d, 2 H, Ar, J = 2.9 Hz);
3.25—3.40 (m, 2 H, CH, diaminocyclohexane); 2.76 (s, 12 H,
N(CH3)2); 1.82—2 (m, 4 H, CH2, diaminocyclohexane);
1.5—1.8 (m, 4 H, CH2, diaminocyclohexane); 1.41 (s, 18 H,
C(CH3)3). 13C NMR (75.5 MHz, CDCl3), δ: 165.8, 153.3, 143.3,
137.5, 118.3, 114.6, 72.43, 42.4, 34.9, 33.1, 29.3, 24.3; Found (%):
C, 73.62; H, 9.32; N, 10.66. C19H27NO6. Calculated (%):
C, 73.81; H, 9.29; N, 10.76.
25
without additional purification, [α]D –152 (c 0.01 MeOH).
1H NMR (300 MHz, CD3OD), δ: 8.45 (s, 2 H, CHN); 7.76
(d, 2 H, Ar, J = 2.15 Hz); 7.61 (d, 2 H, Ar, J = 2.14 Hz); 3.50—3.53
(m, 2 H, CH, diaminocyclohexane); 1.7—1.97 (m, 4 H, CH2
diaminocyclohexane); 1.4—1.7 (m, 4 H, CH2, diaminocycloꢀ
hexane); 1.32 (s, 18 H, C(CH3)3). 13C NMR (75.5 MHz,
CD3OD), δ: 166.61, 163.64, 159.72, 156.85, 138.68, 135.63,
126.64, 118.82, 73.15, 35.94, 34.01, 29.71, 25.25. Found (%):
C, 52.57; H, 5.61; N, 4.33; S, 9.91; Na, 7.32. C28H36N2Na2O8S2.
Calculated (%): C, 52.65; H, 5.68; N, 4.39; S, 10.04; Na, 7.20.
2ꢀ(Diacetoxymethyl)ꢀ6ꢀtertꢀbutylꢀ4ꢀnitrophenyl acetate (2).
3ꢀtertꢀButylꢀ5ꢀnitrosalicylaldehyde (2) (4.56 g, 20 mmol) was
dissolved in acetic anhydride (6.6 mL) with heating to 50 °C.
After 2 was completely dissolved, concentrated sulfuric acid (one
drop) was added to the solution. The precipitate that formed was
filtered off, washed with water, dried in air, and recrystallized
from hexane to yield a cream product (5.28 g, 72%), m.p.
(1R,2R)ꢀCyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)(3ꢀtertꢀbutylꢀ
2ꢀhydroxyꢀ5ꢀtrimethylammoniobenzene) iodide (5). Compound 3
(450 mg, 1.7 mmol) was dissolved in dry MeCN (15 mL) folꢀ
lowed by the addition of CH3I (1.1 mL, 17.3 mmol) to the solution
obtained. The mixture was stirred for 20 h and diluted with diꢀ
ethyl ether (15 mL). The precipitate that formed was filtered off
and washed with a small amount of diethyl ether to yield a yellow
25
product (500 mg, 72%) with m.p. 206—208 °C, [α]D –183
(c 0.01 MeOH). 1H NMR (300 MHz, CD3OD), δ: 8.64 (s, 2 H,
CHN); 7.85 (s, 2 H, Ar, J = 3.3 Hz); 7.61 (s, 2 H, Ar, J = 3.3 Hz);
3.63 (s, 18 H, N(CH3)3); 3.59—3.65 (m, 2 H, CH, diaminocyꢀ
clohexane); 1.93—2.06 (m, 4 H, CH2, diaminocyclohexane);
1.57—1.86 (m, 4 H, CH2, diaminocyclohexane); 1.42 (s, 18 H,
C(CH3)3). 13C NMR (300 MHz, CD3OD), δ: 166.18, 162.94,
141.21, 138.43, 122.76, 121.7, 119.51, 72.83, 58.15, 36.63, 33.83,
29.54, 25.24). Found (%): C, 73.62; H, 9.32; N, 10.66. C19H27NO6.
Calculated (%): C, 73.81; H, 9.29; N, 10.76.
1
122—123 °C. H NMR (300 MHz, CDCl3), δ: 8.4 (s, 1 H Ar);
8.36 (s, 1 H, Ar); 7.76 (s, 1 H, CH(OCOCH3)2); 2.41 (s, 3 H,
OCOCH3); 2.12 (s, 6 H, (OCOCH3)2); 1.39 (s, 9 H, C(CH3)3).
13C NMR (75.5 MHz, CD3Cl), δ: 169.17, 168.24, 151.66, 145.64,
144.76, 131.55, 124.28, 121.69, 83.75, 35.5, 30.21, 21.2, 20.64.
Found (%): C, 55.64; H, 5.85; N, 3.73. C17H21NO8. Calculaꢀ
ted (%): C, 55.58; H, 5.76; N, 3.81.
Nickel(II) (1R,2R)ꢀcyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)ꢀ
bis(3ꢀtertꢀbutylꢀ2ꢀoxybenzeneꢀ5ꢀsulfonate) disodium salt (6a).
A solution of nickel acetate tetrahydrate (19.9 mg, 80 μmol) in
methanol (5 mL) was added to a solution of compound 1
(54.6 mg, 80 μmol) in methanol (1 mL). The solution that was
obtained was stirred for 12 h. The precipitate that formed was
filtered off and washed with a small amount of cold water and
a small amount of cold methanol to yield an orange product
(38 mg, 68%), [α]D25 –460 (c 0.01 MeOH). 1H NMR (300 MHz,
DMSOꢀd6), δ: 7.69 (s, 2 H, CHN); 7.55 (s, 2 H, Ar); 7.4 (s, 2 H,
Ar); 3.11 (m, 2 H CH, diaminocyclohexane); 3.3 (m, 4 H, CH2,
diaminocyclohexane); 1.31 (s, 18 H, C(CH3)3); 1.25 (m, 4 H,
CH2, diaminocyclohexane). 13C NMR (300 MHz, DMSOꢀd6),
δ: 162.97, 159.02, 138.06, 133.42, 129.08, 127.58, 118.9, 69.66,
35.03, 29.32, 28.2, 23.88. UV (CH3OH), λmax/nm (ε/L g–1 m–1):
334 (1117); 409 (939). Found (%): C, 48.29; H, 4.98; N, 4.00;
Na, 6.57; Ni, 8.4; S, 9.16. C28H34N2Na2NiO8S2. Calculated (%):
C, 48.36; H, 4.93; N, 4.03; Na, 6.61; Ni, 8.44; S, 9.22.
Copper(II) (1R,2R)ꢀcyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)ꢀ
bis(3ꢀtertꢀbutylꢀ2ꢀoxybenzeneꢀ5ꢀsulfonate) disodium salt (6b) was
obtained similarly to 6a from compound 1 (54.6 mg, 80 μmol)
and copper acetate monohydrate (16 mg, 80 μmol). The yield of
violet product 6b was 41 mg (73%), [α]D25 –167 (c 0.01 MeOH).
UV (CH3OH), λmax/nm (ε/L g–1 m–1): 363 (1408); 573 (61).
Found (%): C, 47.97; H, 4.93; Cu, 9.0; N, 3.98; Na, 6.53;
S, 9.11. C28H34N2Na2CuO8S2. Calculated (%): C, 48.03; H, 4.89;
Cu, 9.07; N, 4.00; Na, 6.57; S, 9.16.
2ꢀ(Diacetoxymethyl)ꢀ6ꢀtertꢀbutylꢀ4ꢀ(dimethylamino)phenyl
acetate (3). A 10%Pd—C catalyst (0.6 g) was added to a solution
of compound 2 (2.5 g, 6.8 mmol) and formaldehyde (5 mL) in
ethanol (30 mL), and the reaction mixture was stirred for 72 h at
room temperature and atmospheric pressure of hydrogen. The
reaction progress was monitored by TLC using light petroꢀ
leum—acetone (10 : 1) as an eluent. After the reaction was comꢀ
pleted, the mixture was filtered from the catalyst, and the filtrate
was concentrated to obtain a dark yellow oil, which was recrysꢀ
tallized from hexane to yield a cream product (2.1 g, 85%) with
1
m.p. 93—94 °C. H NMR (300 MHz, CDCl3), δ: 7.71 (s, 1 H,
CH(OCOCH3)2); 6.84 (s, 1 H, Ar); 6.8 (s, 1 H, Ar); 2.96 (s, 6 H,
(OCOCH3)2); 2.33 (s, 3 H, 3 H, OCOCH3); 2.09 (s, 6 H,
N(CH3)2); 1.33 (s, 9 H, C(CH3)3). 13C NMR (75.5 MHz,
CD3OD), δ: 172.53, 170.22, 168.17, 150.18, 143.65, 139.22,
130.62, 114.57, 110.62, 86.91, 41.21, 36.08, 31.11, 21.53, 20.67.
Found (%): C, 62.52; H, 7.53; N, 3.78. C19H27NO6. Calculaꢀ
ted (%): C, 62.45; H, 7.45; N, 3.83.
(1R,2R)ꢀ1,2ꢀBisꢀ{[3ꢀtertꢀbutylꢀ5ꢀ(dimethylamino)ꢀ2ꢀhydrꢀ
oxyphenyl]methyleneamino}cyclohexane (4). (R,R)ꢀDiaminoꢀ
cyclohexane Lꢀtartrate (361 mg, 2.74 mmol) and K2CO3 (3.78 g,
27.4 mmol) were dissolved in a water—ethanol mixture (1 : 1, 10 mL)
with heating followed by the slow (dropwise) addition of a soluꢀ
tion of compound 3 (1 g) in ethanol (10 mL) to the solution
obtained. The reaction mixture was heated for 2 h at 80 °C,
cooled, and kept for 16 h. The solution that was obtained was
half concentrated, diluted with water to the initial volume, filꢀ
(1R,2R)ꢀCyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)bis(3ꢀtertꢀ
butylꢀ2ꢀoxyꢀ5ꢀtrimethylammoniobenzene)nickel(II) diiodide (7a)
was obtained similarly to 6a from compound 5 (64.3 mg, 80 μmol)
and nickel acetate tetrahydrate (19.9 mg, 80 μmol). The yield of
orange product 7a was 57 mg (83%), [α]D25 –326 (c 0.01 MeOH).

1618
Russ.Chem.Bull., Int.Ed., Vol. 60, No. 8, August, 2011
Bolotov et al.
1H NMR (300 MHz, DMSOꢀd6), δ: 7.94 (d, 2 H, Ar, J = 2.8 Hz);
7.84 (s, 2 H, CHN); 7.47 (d, 2 H, J = 2.7 Hz); 3.54 (s, 18 H,
N(CH3)3); 3.29 (m, 4 H, CH2, diaminocyclohexane); 3.2 (s, 2 H,
CH, diaminocyclohexane); 1.35 (s, 18 H, C(CH3)3); 1.33 (m, 4 H,
CH2, diaminocyclohexane). 13C NMR (300 MHz, DMSOꢀd6),
δ: 162.42, 159.17, 141.15, 133.49, 123.04, 120.9, 119.31, 69.71,
56.28, 35.71, 29.01, 28.38, 23.64. UV (CH3OH); λmax/nm
(ε/L g–1 m–1): 334 (776); 409 (620). Found (%): C, 47.37;
H, 6.12; I, 29.33; N, 6.47; Ni, 6.8. C34H52I2N4NiO2. Calculatꢀ
ed (%): C, 47.41; H, 6.09; I, 29.47; N, 6.50; Ni, 6.81.
(1R,2R)ꢀCyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)bis(3ꢀtertꢀ
butylꢀ4ꢀoxyꢀ5ꢀtrimethylammoniobenzene)copper(II) diiodide (7b)
was obtained similarly to 6a from compound 5 (64.3 mg, 80 μmol)
and copper acetate monohydrate (16 mg, 80 μmol). The yield of
the violet product was 62 mg (89%), [α]D25 –108 (c 0.01 MeOH);
UV (CH3OH), λmax/nm (ε/L g–1 m–1): 359 (1291), 575 (51).
Found (%): C, 46.99; H, 6.10; Cu, 7.3; I, 29.07; N, 6.42.
C34H52CuI2N4O2. Calculated (%):C, 47.15; H, 6.05; Cu, 7.34;
I, 29.30; N, 6.47.
(CH3OH), λmax/nm (ε/L g–1 m–1): 360 (1189), 563 (44). Found (%):
C, 58.78; H, 6.91; Cu, 5.0; N, 6.61; Ni, 4.6; S, 5.04.
C62H86CuN6NiO10S2. Calculated (%): C, 59.02; H, 6.87; Cu,
5.04; N, 6.66; Ni, 4.65; S, 5.08.
Copper(II) (1R,2R)ꢀcyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)ꢀ
bis(3ꢀtertꢀbutylꢀ2ꢀoxyꢀ5ꢀtrimethylammoniobenzene)copper(II)
(1R,2R)ꢀcyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)bis(3ꢀtertꢀbutylꢀ
2ꢀoxybenzeneꢀ5ꢀsulfonate) (11). The first copper complex 11 was
obtained similarly to complex 8 from compound 1 (27.3 mg,
40 μmol) and copper acetate monohydrate (8 mg, 40 μmol). The
second copper complex was obtained from compound 5 (32.2 mg,
40 μmol) and copper acetate monohydrate (8 mg, 40 μmol). The
yield of the violet product was 30 mg (59%), [α]D25 –136 (c 0.01
MeOH). UV (CH3OH), λmax/nm (ε//L g–1 m–1): 362 (1555),
573 (61). Found (%): C, 58.55; H, 6.89; Cu, 9.9; N, 6.58; S, 5.02.
C62H86Cu2N6O10S2. Calculated (%): C, 58.79; H, 6.84; Cu,
10.03; N, 6.64; S, 5.06.
References
Nickel(II) (1R,2R)ꢀcyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)ꢀ
bis(3ꢀtertꢀbutylꢀ2ꢀhydroxyꢀ5ꢀtrimethylammoniobenzene)nickel(II)
(1R,2R)ꢀcyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)bis(3ꢀtertꢀbutylꢀ
2ꢀoxybenzeneꢀ5ꢀsulfonate) (8). A solution of nickel acetate tetꢀ
rahydrate (10 mg, 40 μmol) in methanol (5 mL) was added to
a solution of compound 1 (27.3 mg, 40 μmol) in methanol (1 mL).
A solution of nickel acetate tetrahydrate (10 mg, 40 μmol) in
methanol (5 mL) was added to a solution of compound 5
(32.2 mg, 40 μmol) in methanol (1 mL). The solutions were
stirred for 12 h, and then methanol was added to each solution
until precipitates that formed were completely dissolved. Two
solutions of thus obtained complexes were mixed, stirred for
12 h, and concentrated to dryness on a rotary evaporator. The
dry residue that was obtained was washed on a filter with a small
amount of cold water and a small amount of cold methanol to
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25
yield an orange product (26 mg, 52%), [α]D –478 (c 0.01
DMSO). UV (DMSO), λmax/nm (ε/L g–1 m–1): 334 (1194), 411
(914). Found (%): C, 59.03; H, 6.94; N, 6.64; Ni, 9.3; S, 5.06
C62H86N6Ni2O10S2. Calculated (%): C, 59.25; H, 6.90; N, 6.69;
Ni, 9.34; S, 5.10.
Nickel(II) (1R,2R)ꢀCyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)bisꢀ
(3ꢀtertꢀbutylꢀ2ꢀoxyꢀ5ꢀtrimethylammoniobenzene)copper(II)
(1R,2R)ꢀcyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)bis(3ꢀtertꢀbutylꢀ
2ꢀoxybenzeneꢀ5ꢀsulfonate) (9). The nickel complex was obtained
from compound 1 (27.3 mg, 40 μmol) and nickel acetate tetraꢀ
hydrate (10 mg, 40 μmol) similarly to complex 8. The copper
complex was obtained from compound 5 (32.2 mg, 40 μmol) and
copper acetate monohydrate (8 mg, 40 μmol). The yield of the
25
brown product was 26 mg (52%), [α]D –308 (c 0.01 MeOH).
UV (CH3OH), λmax/nm (ε/L g–1 m–1): 357 (1348), 566 (44).
Found (%): C, 58.59; H, 6.74; Cu, 5.1; N, 6.70; Ni, 4.7; S, 5.11.
C62H86CuN6NiO10S2. Calculated (%): C, 59.02; H, 6.87; Cu,
5.04; N, 6.66; Ni, 4.65; S, 5.08.
Copper(II) (1R,2R)ꢀcyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)ꢀ
bis(3ꢀtertꢀbutylꢀ2ꢀhydroxyꢀ5ꢀtrimethylammoniobenzene)nickel(II)
(1R,2R)ꢀcyclohexaneꢀ1,2ꢀdiylbis(2ꢀazaethenyl)bis(3ꢀtertꢀbutylꢀ
2ꢀoxybenzeneꢀ5ꢀsulfonate) (10). Nickel complex 10 was obtained
from compound 5 (32.2 mg, 40 μmol) and nickel acetate tetraꢀ
hydrate (10 mg, 40 μmol) similarly to complex 8; the copper
complex, from compound 1 (27.3 mg, 40 μmol) and copper
acetate monohydrate (8 mg, 40 μmol). The yield of the brown
25
product was 30 mg (59%), [α]D –298 (c 0.01 MeOH). UV

Chiral homoꢀ and heterobimetallic systems
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Received March 15, 2011;
in revised form June 16, 2011