Magnetic Nanoparticles: Green and Environment Friendly …
479
O
O
R
R
(CoFe 2 O 4 )
t-BuOH
t-BuOOH
or
Scheme 2 Oxidation of Alkene using CoFe 2 O 4 MNPs catalyst
reused at least for six runs without appreciable reduction on its catalytic activity
(Moeinpour and Khojastehnezhad 2017) (Scheme 3).
Silane ligand could be achieved as shown in Scheme 4. These synthesized
silane ligand was utilized for functionalization of iron oxide magnetic nanoparticles
(Scheme 5). These synthesized Lys-Chol-Magnetic NPs were used for condensation
of benzaldehyde with malononitrile or ethyl cyanoacetate at room temperature as
depicted in Scheme 6. In the above condensation reaction, NH 2 group of amino acid
extracts the proton from the methylene group of ethyl cyanoacetate or malononitrile
to form the corresponding carbanion. Next, the resulting carbanion attacks on the
NH 2 NH 2
H 3 C
OC 2 H 5
O
O
H
Ar
O
CN
CN
O
N
N
H
Ar
H 3 C
CN
NH 2
Catalyst, H 2 O
rt, 10-20 min
+
+
+
Scheme 3 Ni 0.5 Zn 0.5 Fe 2 O 4 @SiO 2 -PPA catalyzed the synthesis of pyranopyrazoles
Si
O
O
O
O
O
Si
HO
OH
HO
O
HO
N
Si
HO
OH
HO
O
HO
N
O
O
R
H 2 N
OH
COOH
R
H 2 N
Et 3 N
H 2 O/EtOH
H 2 O
OH-Chol
R= H(Gly-chol
R= - (CH 2 ) 4 -NH 2 (Lys-Chol)
Scheme 4 Synthesis of silane ligands containing choline amino acid ionic liquid