S. M. Saadati, S. M. Sadeghzadeh
3-Methyl-5-ethylidene-1,3-oxazolidin-2-one (Com-
pound 2c): White powder; mp 74–76 °C. 1H NMR δ=1.64
(dt, J=7.0 Hz, 3H), 2.89 (s, 3H), 4.10 (dq, J=2.2 Hz, 2H),
4.60 (qt, J=7.0 Hz, 1H) ppm. 13C NMR δ=9.6, 30.3, 50.0,
97.3, 141.3, 156.0 ppm.
58.9, 102.2, 126.5, 128.1, 133.8, 146.6, 155.3 ppm. GC-MS
m/z (%)=259 (14), 230 (100), 174 (51), 118 (26), 90 (22).
3-Benzyl-5-ethylidene-1,3-oxazolidin-2-one (Com-
pound 2d): White powder; mp 40–42 °C. 1H NMR δ=1.65
(dt, J=7.0 Hz, 3H), 3.92 (dq, J=2.2 Hz, 2H), 4.42 (s, 2H),
3 Results and Discussion
The Salen-Ru Schiff base was covalently attached onto the
surface of KCC-1 by a nucleophilic reaction, which resulted
in dual catalytically active centers with a synergistic effect to
greatly enhance the catalytic productivity. Furthermore, the
by centrifugation for steady reuse (Scheme 2).
4.53 (qt, J=7.0 Hz, 1H), 7.24–7.40 (m, 5H, Ar) ppm. 13
C
NMR δ=9.9, 47.4, 47.9, 97.9, 128.0, 128.8, 135.2, 141.6,
156.3 ppm.
3-Isopropyl-5-ethylidene-1,3-oxazolidin-2-one (Com-
pound 2e): Yellow oil; 1H NMR δ=1.15 (d, J=6.5 Hz, 6H),
1.69 (dt, J = 6.9 Hz, 3H), 4.02 (dq, J = 2.2 Hz, 2H), 4.12
The morphology and structure of the KCC-1 and KCC-1/
Salen/Ru(II) NPs are further characterized by SEM. Fig-
ure 1a shows an SEM image of highly textured KCC-1
samples, where the samples have spheres of uniform size
with diameters of ~ 300 nm and a wrinkled radial struc-
ture. A close inspection of these images shows that wrin-
kled fibers (with thicknesses of ~ 8.5 nm) grow out from
the center of the spheres and are arranged radially in three
dimensions. Also, the overlapping of the wrinkled radial
structure forms cone-shaped open pores. The SEM image
shows that the entire sphere is solid and composed of fibers.
Furthermore, this open hierarchical channel structure and
fibers are more easily for the mass transfer of reactants and
increase the accessibility of active sites. The SEM images
the morphology of KCC-1 is not change (Fig. 1b). After
being reused ten times, the dandelion-like structure of the
catalyst could be still observed although the dandelion-like
structure collapsed to some extent. The structure similar
between fresh KCC-1/Salen/Ru NPs and the KCC-1/Salen/
(septet, J=6.7 Hz, 1H), 4.60 (qt, J=7.0 Hz, 1H) ppm. 13
NMR δ=9.9, 19.7 ,42.9, 44.8, 97.3, 142.1, 155.3 ppm.
C
3-Methyl-5-benzylidene-1,3-oxazolidin-2-one (Com-
pound 2f): White powder; mp 139–141 °C. 1H NMR δ=2.94
(s, 3H), 4.30 (d, J= 2.1 Hz, 2H), 5.49 (t, J= 2.1 Hz, 1H),
7.19 (t, J = 7.3 Hz, 1H), 7.30 (dd, J = 7.3 Hz, J = 7.6 Hz,
2H), 7.54 (d, J=7.6 Hz, 1H) ppm. 13C NMR δ=30.5, 50.9,
102.9, 127.0, 128.2, 128.7, 133.5, 141.7, 155.6 ppm.
5-(4′-Methylbenzylidene)-3-methyl-1,3-oxazolidin-
2-one (Compound 2 g): White powder; mp 134–136 °C. 1H
NMR δ=7.47 (d, J=8.1 Hz, 2H), 7.15 (d, J=8.0 Hz, 2H),
5.50 (t, J = 2.0 Hz, 1H), 4.30 (d, J = 2.0 Hz, 2H), 3.00 (s,
3H), 2.31 (s, 3 H). 13C NMR δ=155.6, 140.6, 136.3, 130.5,
129.0, 127.9, 102.9, 50.8, 30.2, 21.0 ppm.
5-benzylidene-3-butyl-4-ethyloxazolidin-2-one (Com-
pound 2 h): Yellow oil; 1H NMR δ=1.09 (m, 6H), 1.31–1.40
(m, 2H), 1.52–1.59 (m, 2H), 1.73–1.75 (m, 1H), 1.97–2.01
(m, 1H), 3.01–3.06 (m, 1H), 3.54–3.65 (m, 1H), 4.54 (s,
1H), 5.50 (s, 1H), 7.20 (dd, J = 6.8 Hz, J = 12.8 Hz, 1H),
7.34 (dd, J=7.2 Hz, J=12.8 Hz, 2H), 7.61 (d, J=7.6 Hz,
2H) ppm. 13C NMR δ = 6.3, 13.5, 20.1, 25.0, 29.1, 41.0,
O
O
i
S
O
Br
Br
H2N
N
NH2
OH
EtO
EtO Si
EtO
+
Br
O
H
O
i
O
S
KCC-1
O
Me
N
O
N
O
i
N
Br-
O
Me
Br-
O
i
S
S
O
O
N
O
O
N
N
OH N
OH
Et3N, CH3OH
reflux, 4 h
, CH3OH
Ru
Ru(DMSO)4Cl2
+
N
N
reflux, 2 h
Me
Br-
N
Br-
N
O
O
i
O
S
O
O
O
Scheme 2 Schematic illustration of the synthesis for KCC-1/Salen/Ru(II) NPs
1 3