Silica and Silica Sulfuric Acid Nanoparticles
Combinatorial Chemistry & High Throughput Screening, 2012, Vol. 15, No. 9 711
Table 3) contd…..
(
b
Entry
Substrates
Products
Time(min)
Yield (%)
OH
OAc
1
6
15
91
O N
O N
2
2
OH
OAc
c
1
7
10
10
95
95
HO
AcO
OH
OAc
1
1
8
9
H3C
H C
3
15
30
93
92
HO
AcO
CH3
CH3
CH3
CH3
2
0
OH
OAc
a
b
c
Reaction conditions: Alcohol or Phenol (1.0 mmol); Catalyst (0.015 mmol); Ac
Isolated yields.
Ac O (2.4 mmol); Catalyst (0.03 mmol); Solvent free; rt.
2
2
O (1.2 mmol); Solvent free; rt.
time a simple, clean, and efficient method for the acetylation
of alcohols and phenols under solvent free condition. The
features of this procedure are reusable catalyst, excellent
yields, and enhanced reaction rates, a very small amount of
acetic anhydride usage, retention of chirality and simplicity
of manipulation.
[6]
Dongmin, A.; Yupeng, G.; Zou, B.; Yanchao, Z.; Wang, Z. A study
on the consecutive preparation of silica powders and active carbon
from rice husk ash. Biomass Bioenergy., 2011, 35, 1227-1234.
Cordeiro, G. C.; Filho, R. D. T.; Tavares, L. M.; Fairbairn, E. M.
R.; Hempel, S. Influence of particle size and specific surface area
on the pozzolanic activity of residual rice husk ash. Cem. Concr.
Compos., 2011, 33, 529-534.
Liou, T. H.; Yang, C.C. Synthesis and surface characteristics of
nanosilica produced from alkali-extracted rice husk ash. Mater. Sci.
Engin. B., 2011, 176, 521-529.
[7]
[
[
[
8]
CONFLICT OF INTEREST
9]
Witoon, T.; Chareonpanich, M.; Limtrakul, J. Synthesis of bimodal
porous silica from rice husk ash via sol-gel process using chitosan
as template . Mater. Lett., 2008, 62, 1476-1479.
The authors confirm that this article content has no
conflict of interest.
10]
Salavati-Niasari, M.; Javidi, J.; Davar, F. Sonochemical synthesis
of Dy2(CO
3
)
3
nanoparticles, Dy(OH)
3
nanotubes and their
conversion to Dy
Ultrasonics Sonochemistry., 2010, 17, 870-877.
2
O
3
nanoparticles Ultrasonics Sonochemistry.
ACKNOWLEDGEMENT
[11]
Stamatisa, A.; Giasafakia, D.; Christoforidis b, K.C.;
Deligiannakisb, Y.; Louloudia, M. The catalytic function of SiO -
2
immobilized Mn(II)-complexes for alkene epoxidation with H O .
2 2
Journal of Molecular Catalysis A: Chemical, 2010, 319, 58-65.
Authors are grateful to the council of Iran National
Science Foundation and University of Kashan for supporting
this work by Grant No (159271/18).
[
12]
13]
Ahmed, A. E.; Adam, F. Indium incorporated silica from rice husk
and its catalytic activity. Microporous Mesoporous Materials,
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