tAn efficient, cost effective and environmental friendly PEGylated magnetic nanoparticle catalyzed oxida-tive cyanation via CH activation of tertiary amines to corresponding -aminonitriles using hydrogenperoxide as oxidant and sodium cyanide as cyanide source is described. The synthesized nanocatalyst waseasily recovered with the help of external magnet and was successfully reused for several runs withoutany significant loss in catalytic activity.

1. Applied Catalysis A: General 498 (2015) 25–31
Contents lists available at ScienceDirect
Applied Catalysis A: General
journal homepage: www.elsevier.com/locate/apcata
PEGylated magnetic nanoparticles (PEG@Fe3O4) as cost effective
alternative for oxidative cyanation of tertiary amines via C H
activation
Vineeta Panwar, Pawan Kumar, Ankushi Bansal, Siddharth S. Ray, Suman L. Jain∗
Chemical Sciences Division, CSIR-Indian Institute of Petroleum, Dehradun 248005, India
a r t i c l e i n f o
Article history:
Received 19 December 2014
Received in revised form 27 February 2015
Accepted 17 March 2015
Available online 24 March 2015
Keywords:
Oxidative cyanation
Polyethylene glycol
Heterogeneous catalyst
Magnetic nanoparticle
C H activation
a b s t r a c t
An efficient, cost effective and environmental friendly PEGylated magnetic nanoparticle catalyzed oxida-
tive cyanation via C H activation of tertiary amines to corresponding ␣-aminonitriles using hydrogen
peroxide as oxidant and sodium cyanide as cyanide source is described. The synthesized nanocatalyst was
easily recovered with the help of external magnet and was successfully reused for several runs without
any significant loss in catalytic activity.
© 2015 Elsevier B.V. All rights reserved.
1. Introduction
Development of efficient and selective catalytic methods for
C H bond functionalization is an area of current research interest
[1–5]. The direct utilization of C H bonds offer several advantages
such as it avoids the pre-functionalization of the substrates and
reduces the synthetic procedures, which makes the synthesis more
attractive from both environmental and economical viewpoints
[6–11]. In this regard, transition-metal-catalyzed C H bond acti-
vation, particularly of unactivated sp3 C H bonds, has emerged to
be a promising but highly challenging approach in organic syn-
thesis [12–15]. Recently, the direct oxidative cyanation of C H
bonds in tertiary amines to give corresponding ␣-aminonitriles
has attracted much interest as these compounds are highly useful
and versatile intermediates which find extensive applications in a
wide range of natural products and nitrogen containing bioactive
compounds such as alkaloids [16–19]. Further, these bi-functional
organic compounds having adjacent functional groups show dual
reactivity as the nucleophilic addition provides an easy access to
various compounds such as ␣-amino aldehydes, ketones and ␤-
amino alcohols [20–25]. So far a number of metal-based catalysts,
such as Fe [26–28], Ru [29,30], V [31], Mo [32], Au [33] and Re [34]
in the presence of oxidants such as molecular oxygen, hydrogen
∗ Corresponding author. Tel.: +91 135 2525788; fax: +91 135 2660202.
E-mail address: suman@iip.res.in (S.L. Jain).
peroxide, tert-butyl hydroperoxide (TBHP) have been reported for
the direct oxidative cyanation of tertiary amines. Photoredox cat-
alysts mainly based on ruthenium have also been reported for the
oxidative ␣-cyanation of sp3 C H bonds of tertiary amines [35–38].
However, the use of expensive metals such as ruthenium, rhenium,
multi-step as well as high cost synthesis of catalysts make these
methods less desirable from environmental and economic points
of view. Furthermore, in some instances inefficient recovery of the
catalyst still leave a scope for developing an efficient and improved
method for the direct synthesis of ␣-aminonitriles from the oxida-
tive cyanation of tertiary amines.
In continuation to our efforts towards developing efficient and
cost-effective methodologies for organic transformations [39–41],
herein we report a facile, highly efficient and selective method for
the oxidative cyanation of tertiary amines via C H bond activation
using PEGylated magnetic nanoparticles as catalyst in the pres-
ence of hydrogen peroxide as oxidant and NaCN in acetic acid as
a cyanide source (Scheme 1). Furthermore, facile recovery of the
catalyst with the use of an external magnet makes the developed
method attractive for wider applications.
2. Experimental
2.1. Materials
Ferric chloride hexa-hydrate (FeCl3·6H2O), ferrous chloride
tetra-hydrate (FeCl2·4H2O) and ammonium hydroxide (NH4OH,
http://dx.doi.org/10.1016/j.apcata.2015.03.018
0926-860X/© 2015 Elsevier B.V. All rights reserved.

2. 26 V. Panwar et al. / Applied Catalysis A: General 498 (2015) 25–31
Scheme 1. PEGylated magnetic nanoparticles catalyzed oxidative cyanation of ter-
tiary amines.
25% of ammonia), succinic acid (>99%), polyethylene gly-
col (PEG-300) N-(3-dimethylaminopropyl)-N -ethylcarbodiimide
hydrochloride (EDC) and ion exchange resin (Indion 130) was pur-
chased from Aldrich were of analytical grade and used without
further purification. Acetone, methanol was all analytical grade
reagents and stored in cold and dark. Distilled water was used
throughout. Hydrogen peroxide (35%) and ethanol was of analyti-
cal grade and procured from Alfa Aesar. All other chemicals were
of A.R. grade and used without further purification.
2.2. Techniques used
The rough surface morphology of the synthesized catalyst was
determined with the help of scanning electron microscopy (SEM)
by using Jeol Model JSM-6340F. Inner fine structure of sam-
ples was determined with high resolution transmission electron
microscopy using FEI-TecnaiG2 TwinTEM operating at an accel-
eration voltage of 200 kV. The samples for TEM analysis were
made by depositing very dilute aqueous suspension of samples
on carbon coated TEM grid. Phase structure and crystalline state
of material was determined on Bruker D8 Advance diffractome-
ter at 40 kV and 40 mA with Cu K␣ radiation ( = 0.15418 nm).
For XRD, samples were prepared on glass slide by adding well
dispersed catalyst in slot and drying properly. Solid UV–visible
spectra of samples were collected on Perkin Elmer lambda-19
UV–vis–NIR spectrophotometer using a 10 mm quartz cell, using
BaSO4 as reference. The functional groups entities were confirmed
by Fourier transform infrared spectra using Perkin–Elmer spectrum
RX-1 IR spectrophotometer having Potassium bromide window.
Nitrogen adsorption desorption isotherm was used for calculat-
ing surface properties like Brunauer–Emmet–Teller (SBET) surface
area, Barret–Joiner–Halenda (BJH) porosity (rp), pore volume (VP)
of samples at 77 K by using VP; Micromeritics ASAP2010. The ther-
mal degradation pattern of samples for calculating amount of PEG
loading on Fe3O4 nanoparticles was estimated by thermo gravi-
metric analyses (TGA) using a thermal analyzer TA-SDT Q-600. The
TGA analysis was carried out in the temperature range of 40–800 ◦C
under nitrogen flow with heating rate 10 ◦C/min. 1H NMR and 13C
NMR spectra of the cyanation products were recorded at 500 MHz
by using Bruker Avance-II 500 MHz instrument.
2.3. Synthesis of Fe3O4 nanoparticles [42]
The Fe3O4 magnetic nanoparticles were synthesized by co-
precipitation of Fe+2 and Fe+3 solutions under alkaline conditions.
In brief 1.99 g (10 mmol) of FeCl2·4H2O and 3.24 g (12 mmol) of
FeCl3·6H2O were dissolved in 50 mL of distilled water. A separate
solution of NH4OH was made by dissolving 30 mL NH4OH (25%
ammonia) in 50 mL of distilled water. Both the solutions in the
beaker were allowed to stir for about half an hour, to achieve uni-
form mixing. After that NH4OH solution was added drop wise into
the first solution till a pH of 9 is obtained. The obtained solution
was stirred continuously that generates magnetic nanoparticles.
The obtained precipitates were separate with the help of external
magnet and washed with distilled water and ethanol and dried at
120 ◦C overnight then grinded. Finally the black coloured iron oxide
nanoparticles were obtained.
2.4. Succinic acid functionalized Fe3O4 nanoparticles [43]
To getting succinic acid functionalized Fe3O4, succinic acid
(2.4 g) was added to an aqueous solution of Fe3O4 nanoparticles
(150 mL, 0.3 mg) and this reaction mixture was allowed to stir for
24 h under vigorous stirring. The synthesized succinic acid func-
tionalized Fe3O4 nanoparticles were recovered by external magnet
and washed with water continuously to wash away unreacted suc-
cinic acid.
2.5. Synthesis of PEGylated magnetic nanoparticles (PEG@Fe3O4)
EDC (120 mg, 0.6 mmol) and ion exchanger (180 mg, 1.5 mmol)
were added to an aqueous solution of Fe3O4–succinic acid nanopar-
ticles (25 mL, 60 mg) and the mixture was stirred for 30 min at room
temperature. Afterwards, PEG-300 (3.33 mL) was added to the reac-
tion mixture and stirred for 24 h at room temperature. Finally,
Fe3O4–succinic acid–PEG nanoparticles were recovered and puri-
fied as above by means of three steps of magnetic separation,
removal of the supernatant and washing with water to obtain 1.2 g
of Fe3O4–succinic acid–PEG nanoparticles as a black powder.
2.6. General experimental procedure
For the cyanation reaction, tertiary amine (1 mmol), NaCN
(1.2 mmol), MeOH (4 mL), catalyst (0.1 g), and AcOH (1 mL) was
charged in a 25 mL round bottomed flask equipped with a magnetic
stirrer. Aqueous hydrogen peroxide (2.5 mmol, 35 wt%) was added
drop wise over a period of 30 min to the resulting stirred reaction
mixture, and the stirring was continued at room temperature. The
progress of reaction was monitored by TLC. After completion of
the reaction, the catalyst was recovered by an external magnet.
Dichloromethane was added in the obtained solution. The organic
layer was washed with water, dried over anhydrous Na2SO4 and
concentrated under vacuum to give crude product, which was
purified by flash chromatography to afford pure ␣-aminonitrile.
The product of cyanation of tertiary amines to corresponding ␣-
aminonitriles was identified with the help of GC–MS (EI quadrupol
mass analyzer, EM detector) by comparing their spectral data with
authentic samples. The yield and selectivity of product was also
determined with GC–MS.
3. Results and discussion
3.1. Synthesis and characterization of catalyst
The magnetic Fe3O4 nanoparticles were synthesized by using
co-precipitation method by mixing of acidic solution of Fe+2,
Fe+3 and dropping it in a weak alkaline solution as following
the literature procedure [42]. The obtained Fe3O4 nanoparticles
were subsequently functionalized with succinic acid as a linker to
provide active COOH groups for ester bond formation with PEG
[43]. Thus obtained succinic acid modified magnetic nanoparticles
were treated with polyethylene glycol (PEG300) in the pres-
ence of EDC (N-(3-dimethylaminopropyl)-N -ethylcarbodiimide
hydrochloride) and ion exchanger (Indion 130) as shown in
Scheme 2.
The rough surface morphology of magnetic nanoparticles
(Fe3O4) and PEG@Fe3O4 catalyst was determined by scanning elec-
tron microscopy (SEM) as shown in Fig. 1. The SEM image of Fe3O4
confirmed that small sized particles in the range of 50–100 nm
were obtained (Fig. 1a). However, in case of PEGylated nanoparti-
cles some lumps type morphology was observed, which is probably
due to the coating of magnetic nanoparticles with PEG molecules
(Fig. 1b). The EDX pattern of Fe3O4 nanoparticles (Fig. 1c) gave sharp

3. V. Panwar et al. / Applied Catalysis A: General 498 (2015) 25–31 27
Scheme 2. Synthesis of PEGylated magnetic nanoparticles (PEG@Fe3O4).
peaks of iron, which was found to be decreased significantly after
coating with PEG molecules (Fig. 1d).
The fine structure of Fe3O4 nanoparticles and PEG@Fe3O4 was
executed with TEM. TEM image of Fe3O4 showed that most of the
nanoparticles were of spherical in shape and are in 10–25 nm in size
(Fig. 2a). After the coating of PEG the spherical geometry remained
intact, however the surface has become rough which is assumed
due to the coating of magnetic nanoparticles with PEG (Fig. 2b).
The bright spots in SAED pattern clearly indicated that crystalline
nature of Fe3O4 remained intact during the coating step (Fig. 2c).
FT-IR spectra of Fe3O4 (Fig. 3a) showed characteristic peaks at
574 cm−1 and 1384 cm−1 due to Fe O bending and Fe O stretch
vibrations. The peak at 1627 cm−1 was attributed to the bending
vibration of water adsorbed on the surface of Fe3O4. The peak
at 3415 cm−1 was appeared due to the OH present on the sur-
face of Fe3O4 nanoparticles [44,45]. The FT-IR spectra of PEG300
showed its characteristic vibrations at 3405 cm−1 and 1403 cm−1
due to the OH stretching and bending vibration respectively along
with at 2918 cm−1 (C H stretch), 1595 cm−1 ( COO stretch),
1460 cm−1 (C H bending and scissoring), 1342 cm−1 ( OH bend-
ing), 1209 cm−1 (C O stretch), and 1164 cm−1 ( C O C stretch)
and other peaks in fingerprint region (Fig. 3b) [46,47]. The presence
of characteristic peaks of PEG in the FTIR spectra of PEG@Fe3O4
further confirmed the successful formation of PEGylated magnetic
Fe3O4 nanoparticles (Fig. 3c).
XRD diffractogram of Fe3O4 showed the characteristic peaks at
2Â value 30.28◦ (2 2 0), 35.48◦ (3 1 1), 43.36◦ (4 0 0), 54.04◦ (4 2 2),
57.28◦ (5 1 1) and 62.96◦ (4 4 0) that were matched well with JCPDS
card No. 65–3107 (Fig. 4a) [48–50]. The high intensity of peaks con-
firmed the crystalline nature of the magnetic Fe3O4 nanoparticles.
While in PEGylated magnetic (PEG@Fe3O4) nanoparticles the peaks
of Fe3O4 at 35.48◦ (3 1 1), 43.36◦ (4 0 0), 57.28◦ (5 1 1) and 62.96◦
(4 4 0) were observed but the intensity of peaks was significantly
reduced due to coating of amorphous PEG on the surface of Fe3O4
(Fig. 4b).
Nitrogen adsorption desorption isotherm was used for deter-
mining the surface properties. For Fe3O4 the loop of isotherm was
of type (IV) confirms the mesoporous nature of material (Fig. 5a)
[51] BET surface area (SBET), total pore volume (VP) and mean pore
diameter (rp) for Fe3O4 was found to be 53.24 m2 g−1, 0.12 cm3 g−1
and 2.58 nm respectively. For PEG@Fe3O4 the isotherm was type
(IV) and BET surface area (SBET), total pore volume (VP) and
mean pore diameter (rp) for Fe3O4 was found to be 83.93 m2 g−1,
0.3759 cm3 g−1 and 7.98 nm respectively (Fig. 5b). This change in
surface properties was assumed due to coating of PEG on the sur-
face of Fe3O4 nanoparticles the rough surface provides more pore
for the adsorption of nitrogen.
Solid UV–visible absorption spectra of magnetic Fe3O4 nanopar-
ticles gave a broad absorption pattern from 200 to 600 nm, which
is attributed to the d-orbital transitions of Fe3O4 (Fig. 6a) [52]. In
case of PEGyted Fe3O4 nanoparticles, the intensity of absorption
pattern was increased, but there was no specific absorption band
was appeared due to absence of conjugation in PEG (Fig. 6b). The
increased intensity of absorption in PEG@Fe3O4 was assumed due
to mixed transition of composite.
Thermal degradation behaviour of the synthesized Fe3O4
nanoparticles and PEGylated Fe3O4 nanoparticles was elucidated
by TGA (Fig. 7). Because the TG was measured at N2 atmosphere, the
oxidation of Fe3O4 NPs was greatly reduced. The weight loss below
200 ◦C could be attributed to the adsorbed water in the samples
(Fig. 7a) [53]. In PEGylated Fe3O4 nanoparticles a sharp decrease in
weight loss between 200 and 800 ◦C was observed as compared to
neat Fe3O4 NPs. The main weigh loss at 200–350 ◦C and 450–800 ◦C
could be attributed to first decomposition and second decomposi-
tion of organic components, which were presented on the surface
of Fe3O4 NPs (Fig. 7b) [54].

4. 28 V. Panwar et al. / Applied Catalysis A: General 498 (2015) 25–31
Fig. 1. SEM images of (a) Fe3O4 magnetic nanoparticles and (b) PEG@Fe3O4 and EDX pattern of (c) Fe3O4 and (d) PEG@Fe3O4.
Fig. 2. TEM images of (a) Fe3O4, (b) PEG@Fe3O4 and (c) SEAD pattern of PEG@Fe3O4.
3.2. Catalytic activity
The catalytic activity of the synthesized PEGylated magnetic
NPs was tested for the oxidative cyanation of tertiary amines to
␣-aminonitriles using hydrogen peroxide as oxidant and NaCN in
acetic acid as a cyanide donor at room temperature (Scheme 1).
N,N-Dimethylaniline was chosen as the model substrate to opti-
mize the reaction conditions with various oxidants and solvents at
room temperature using NaCN in acetic acid as the cyanide source
(Table 1). No product was obtained when the reaction was car-
ried out without catalyst or using PEG without containing iron NPs
as catalyst under otherwise similar reaction conditions (Table 1,
entries 1 and 2). For the comparison purpose we also performed
the reaction using neat magnetic NPs as catalyst under identical
experimental conditions. The neat magnetic particles were found
to be ineffective and gave only trace yield of the desired reaction
product (Table 1, entry 3). The poor activity of neat MNPs could be
ascribed to the aggregation of MNPs and oxidation of nanoparticles

5. V. Panwar et al. / Applied Catalysis A: General 498 (2015) 25–31 29
Fig. 3. FTIR spectra of (a) Fe3O4, (b) PEG and (c) PEG@Fe3O4.
Fig. 4. XRD diffractogram of (a) Fe3O4 and (b) PEG@Fe3O4.
Fig. 6. UV–vis absorption spectra of (a) Fe3O4 and (b) PEG@Fe3.
Fig. 7. TGA thermogram of (a) Fe3O4 and (b) PEG@Fe3O4.
Fig. 5. BET Ads Des isotherm and pore size distribution of (a) Fe3O4 and (b) PEG@Fe3O4.

6. 30 V. Panwar et al. / Applied Catalysis A: General 498 (2015) 25–31
Table 1
Results of the optimization experimentsa
.
Entry Catalyst Solvent Oxidant Yield (%)b
TOF (h−1
)
1 – MeOH H2O2 – –
2 PEG MeOH H2O2 – –
3 Fe3O4 MeOH H2O2 Trace –
4 Succinic acid@Fe3O4 MeOH H2O2 62.4 12.5
5 PEG@Fe3O4 MeOH H2O2 75c
, 94a
, 94.5d
18.8
6 PEG@Fe3O4 MeOH – – –
7 PEG@Fe3O4 MeOH O2 22 4.4
8 PEG@Fe3O4 MeOH TBHP 48 9.6
9 PEG@Fe3O4 CH2Cl2 H2O2 5 1.0
10 PEG@Fe3O4 Water H2O2 22 4.4
11 PEG@Fe3O4 CH3CN H2O2 34 6.8
12 PEG@Fe3O4 EtOH H2O2 86 17.2
a
Reaction conditions: substarte (1 mmol), catalyst (0.1 g), NaCN (1.2 mmol), AcOH
(1 mL), solvent (4 mL) in the presence of H2O2; reaction time 5 h.
b
Isolated yield.
c
Using 0.05 g of catalyst.
d
Using 0.2 g of catalyst.
under the reaction conditions. Similarly, succinic acid function-
alized magnetic nanoparticles exhibited poor catalytic activity as
compared to the PEGylated magnetic NPs for the oxidative cya-
nation of N,N-dimethylaniline to corresponding ␣-aminonitrile
under otherwise identical reaction conditions (Table 1, entries 4
and 5). The superior catalytic activity of the PEGylated magnetic
nanoparticles was assumed due to their higher chemical stability,
non-aggregation and preventive oxidation due to the presence of
PEG coating. Next, we studied the effect of various oxidants such as
molecular oxygen, hydrogen peroxide and TBHP under described
reaction conditions (Table 1, entries 5 and 7–8). Among the var-
ious oxidants, hydrogen peroxide was found to be best oxidant
for this transformation (Table 1, entry 5). However there was no
reaction occurred in the absence of any oxidant (Table 1, entry
6). The presence of acetic acid was found to be essential and in
its absence no reaction was occurred even after prolonged reac-
tion time (10 h). Among the various solvents such as acetonitrile,
methanol, dichloromethane and water studied (Table 1, entries 5
and 9–12), methanol was found to be best solvent for the present
transformation. Further, we evaluated the effect of catalyst amount
on the conversion of N,N-dimethylaniline in methanol at room
temperature under otherwise identical experimental conditions.
Initially the reaction was found to be increased with increase in
catalyst amount from 0.05 to 0.1 g with respect to 1 mmol of the
substrate, however further increase in catalyst amount from 0.1 to
0.2 g did not affect the reaction to any significant extend (Table 1,
entry 4).
With the optimal conditions for the highly efficient and
selective oxidative cyanation of tertiary amines in hand, the
scope of the reaction was explored for the different substrates
under described reaction conditions. The results of these exper-
iments are summarized in Table 2. As shown in Table 2,
substituted N,N-dimethylanilines with electron-donating and
electron-withdrawing groups were selectively and efficiently con-
verted into the corresponding ␣-aminonitriles in good to excellent
yields (Table 2, entries 2–6). N,N-Dimethyl-o-toluidine offered
a slightly lower yield (78% yield) than N,N-dimethyl-p-toluidine
(89% yield) owing to steric hindrance. In case of N-methyl-N-
ethylaniline, the N-methyl group was oxidized chemoselectively to
give the corresponding N-ethyl-N-phenylaminoacetonitrile in 80%
yield (Table 2, entry 7). The developed catalytic system could also be
applied efficiently for oxidative cyanation of cyclic amines such as
piperidine, and tetrahydroisoquinoline to give the corresponding
␣-aminonitriles in moderate to high yields (Table 2, entries 8–10).
Aliphatic tertiary amines like tert-butyl amine did not produce any
product (Table 2, entry 11). But the tertiary amines having benzyl
Table 2
PEG@Fe3O4 catalyzed oxidative cyanation of tertiary aminesa
.
Entry Reactant Product Time (h) Yield (%)b
TOF (h−1
)
1
N
CH3
CH3
N
CH3
CH2CN 5 94 18.8
2
N
CH3
CH3
N
CH3
CH2CN 4.5 78 17.3
3
N
CH3
CH3
Me N
CH3
CH2CN
Me
4.5 89 19.7
4
N
CH3
CH3
N
CH3
CH2CN 4.5 80 17.7
5
N
CH3
CH3
Br
N
CH3
CH2CN
Br
5.0 72 14.4
6
N
CH3
CH3
Br N
CH3
CH2CN
Br
5.0 81 16.2
7 N
CH3
C2H5 N
CN
C2H5
4.0 86 21.5
8 N
N
NC
5.5 84 15.2
9 N
N
NC
5.5 86 15.6
10 N
Ph
N
Ph
CN
5.0 91 18.2
11 (n-Bu)3N – 32 – –
12
N
CH3
CH3 N
CH2CN
CH3
24 34 1.4
13
N
CH3
CH3 N
CH2CN
CH3
24 47 1.9
a
Reaction conditions: Substrate (1 mmol), PEG@Fe3O4 catalyst (0.1 g), NaCN
(1.2 mmol), AcOH (1 mL), MeOH (4 mL) in the presence of H2O2 at room temperature.
b
Isolated yield.
groups were sluggish in reaction with poor yield (Table 2, entries
12–13).
Furthermore, we checked the recycling of the PEGylated MNPs
by using N,N-dimethylaniline as a model substrate. After comple-
tion of the reaction, the catalyst was easily recovered from reaction
mixture by using an external magnet, washed with methanol and
dried. The recovered catalyst was used for six runs using fresh
substrates and oxidant. The results of recycling experiments are
summarized in Fig. 8. As shown in Fig. 8, the yield of the desired
product in all cases was found to be almost similar which confirmed
that the developed catalyst can be reused efficiently without any
significant loss in activity for several runs.
Although, the mechanism of reaction is not clear at this stage,
the probable mechanistic pathway is shown in the Scheme 3. In
analogy to the mechanism proposed by Murahashi et al. [29] we

7. V. Panwar et al. / Applied Catalysis A: General 498 (2015) 25–31 31
Fig. 8. Results of recycling experiments.
Scheme 3. Possible mechanism of the reaction.
can assume that the reactive oxo-iron (IV) species derived from
iron and H2O2 abstracts hydrogen from the ␣-carbon of the tertiary
amines to give cationic intermediate. The nucleophilic attack of the
HCN, generated in situ by the reaction of NaCN and AcOH yielded
corresponding ␣-aminonitrile as shown in Scheme 3.
4. Conclusion
In summary, we have described a novel, highly efficient and
cost effective PEGylated magnetic nanoparticles as catalyst for the
oxidative cyanation via C H activation of tertiary amines with
hydrogen peroxide in the presence of sodium cyanide in acetic acid
as cyanide source at room temperature to give ␣-aminonitriles in
high to excellent yields. The developed catalyst was easily recov-
ered with the effect of an external magnet and efficiently recycled
for several runs without significant loss of activity.
Acknowledgement
We are thankful to the Director, CSIR-IIP for his kind permis-
sion to publish these results. VP and PK acknowledge the CSIR,
New Delhi, for their Research Fellowships. Analytical department
of institute is kindly acknowledged for the analysis of samples.
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