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DINDARLOO INALOO ET AL.
0.35 ml of DIPEA (2 mmol) were added to the mixture
and it was stirred at 80 C for 12 hr. The final particles
were separated from the solution with an external mag-
netic field, washed three times with ethanol and water,
and dried at 70 ꢀC for 4 hr.
evaporator. The product was purified by column chroma-
tography on silica gel using petroleum ether/ethyl acetate
(9:1) as the solvent or recrystallized (See supporting infor-
mation for 1H and 13C NMR of the products).
ꢀ
2.4 | General procedure for the cross-
coupling reaction of aryl carbamate and/or
aryl Sulfamates with olefins (heck cross-
coupling) (5a-5 t)
2.2.5 | Preparation of Fe3O4@SiO2-EDTA-
Ni(0) NPs
For the synthesis of Fe3O4@SiO2-EDTA NPs, 0.58 g of
EDTA (2 mmol) was dispersed in 20 ml of DMSO and
then, thionyl chloride (SOCl2, 2 mmol) was added
dropwise over 10 min through a constant pressure drop
funnel. Next, 1.5 g of Fe3O4@SiO2-TCT-NH2 was added
to the mixture and stirred for 2 hr at room temperature.
The functionalized ethylenediaminetetraacetic acid by
Fe3O4@SiO2-TCT-NH2 nanomaterial was then isolated
by an external magnet, washed with sodium carbonate
solution (0.1 mol L−1), acetone and deionized water, and
dried under vacuum at 60 ꢀC for 2 hr. The resultant
Fe3O4@SiO2-EDTA (1.5 g) was dispersed in 10 ml metha-
nol. Afterward, 1 g of nickel (II) acetate tetrahydrate
(4 mmol) was added to the mixture and stirred for 2 hr
under the reflux conditions. In the next step, 15 ml of
N2H4·H2O (1 equiv.) was slowly added to the obtained
mixture and it was allowed to be stirred for more 2 hr.
The resulting solid of Fe3O4@SiO2-EDTA-Ni(0) was sepa-
rated from the reaction mixture by an external magnet,
washed with ethanol and THF for three times, and dried
at 60 ꢀC for 3 hr to afford the final catalyst.
Aryl carbamate and/or aryl sulfamate (1.0 mmol), olefin
(1.0 mmol), potassium phosphate (2.0 mmol, 430 mg),
Fe3O4@SiO2-EDTA-Ni(0) NPs (0.018 g, 1 mol %) and eth-
ylene glycol (3.0 ml) were added into a round-bottomed
ꢀ
flask and stirred at 120 C for 6 hr under the air atmo-
sphere. The reaction process was monitored by TLC using
petroleum ether/ethyl acetate and/or GC. After the com-
pletion of the reaction, the reaction mixture was cooled to
room temperature and the nanocatalyst was separated
from the mixture with an external magnetic field. Then,
10 ml of distilled water was added and the reaction mix-
ture was subsequently extracted with ethyl acetate
(3 × 10 ml). The organic phases were dried over anhydrous
MgSO4 and the crude product was obtained after removing
the ethereal solution by a rotary evaporator. The product
was purified by column chromatography on silica gel
using petroleum ether/ethyl acetate (9:1) (See supporting
information for 1H and 13C NMR of the products).
3 | RESULTS AND DISCUSSION
2.3 | General procedure for the cross-
coupling reaction of aryl carbamate and/or
aryl Sulfamates with aryl Boronic acids
(Suzuki-Miyaura cross-couplings) (3a-3x)
The whole preparation route to Fe3O4@SiO2-EDTA-
Ni(0) NPs includes five steps is illustrated in Scheme 2.
The Fourier transform infrared (FT-IR) spectra of all syn-
thetic approaches of the final catalyst are shown in
Figure 2a-g. The FT-IR spectrum of Fe3O4 MNPs demon-
strates a band at 570 cm−1 due to the stretching vibration
of Fe-O and also, a broad band at 3441 cm−1 is attributed
to the presence of surface hydroxyl groups (Figure 2a).
The broad and intense band at 1090 cm−1 in the spec-
trum of Fe3O4-SiO2 is assigned to the asymmetric
stretching bands of Si-O-Si in the silica shell. Further-
more, the band at 801 cm−1 is assigned to the Si-O-Si
symmetric stretch (Figure 2b). The presence of the
anchored NH2 and CH2 groups, originating from the
amino-propyl moiety of APTES was confirmed by
stretching vibrations at 3300–3370 cm−1 and
2810–2986 cm−1, respectively (Figure 2c). After the modi-
fication with cyanuric chloride (Fe3O4@SiO2-TCT,
Figure 2d), the appearance of new bands at 1511, 1564
and 1711 cm−1 correspond to C=N stretching vibration.
Aryl carbamate and/or aryl sulfamate (1.0 mmol),
arylboronic acid (1.0 mmol), potassium phosphate
(2.0 mmol, 430 mg), Fe3O4@SiO2-EDTA-Ni(0) NPs
(0.018 g, 1 mol %) and ethylene glycol (3.0 ml) were
ꢀ
added into a round-bottomed flask and stirred at 120 C
for 6 hr under the air atmosphere. The reaction process
was monitored by TLC using petroleum ether/ethyl ace-
tate and/or GC. After the completion of the reaction, the
reaction mixture was cooled to room temperature and
the nanocatalyst was separated from the mixture with an
external magnetic field. Then, 10 ml of distilled water
was added and the crude was subsequently extracted
with ethyl acetate (3 × 10 ml). The organic phase was
dried over anhydrous MgSO4 and the crude product was
obtained after removing the ethereal solution by a rotary