Paper
Catalysis Science & Technology
an He flow with a temperature ramp of 5 °C min−1 up to 400
°C. Subsequently, the sample was cooled to 100 °C; at this
point, NH3 pulses of 25.3 cm3 min−1 were applied. The
sample was then heated to 600 °C with a ramp of 5 °C min−1
to induce desorption of NH3. A procedure similar to the one
described for NH3-TPD was employed for temperature
programmed desorption of CO2 (CO2-TPD), the main
difference being the lower temperature (50 vs. 100 °C) at
which CO2 pulses are fed to the sample. For calculating the
number of acidic or basic sites, it was assumed that only one
molecule of NH3 or CO2 can adsorb on a single site. Detailed
procedure in ESI† (E1).
Claisen–Schmidt
condensation
reaction,
benzylideneacetophenone (chalcone): 1H NMR (CDCl3, 100
MHz) δ = 7.40–7.67 (m, 9H), 7.82 (d, J = 15.7 Hz, 1 H), 8.03
(dd, J = 8.4, 1.4 Hz, 2 H) ppm. 13C NMR (400 MHz, CDCl3); δ
= 122.26, 128.44, 128.59, 128.65, 128.77, 130.65, 132.91,
134.58, 137.26, 145.03, 198.24.
Henry reaction, 2-nitrovinylbenzene (β-nitrostyrene): 1H
NMR (CDCl3, 400 MHz) δ 7.41–7.51 (m, 3H), 7.54–7.57 (m,
2H), 7.59 (d, J = 13.7 Hz, 1H), 8.01 (d, J = 13.7 Hz, 1H) ppm.
13C NMR (100 MHz, CDCl3); δ = 129.10, 129.39, 130.08,
130.15, 132.11, 137.69, 139.03.
The aldol condensation of butyraldehyde was performed Conflicts of interest
in a batch reaction system, under vigorous magnetic stirring
T. J., J. F. and P. C. A. B. are listed as inventors on a patent
and a nitrogen atmosphere. Prior to the reaction, all the SHC
solids were thermally activated at 200 °C for 4 h. In a typical
experiment, a 50 mL two-necked flask connected to a reflux
condenser was filled with 55.6 mmol of butyraldehyde, 3
mol% SHC (mol% = catalyst loading (mmol)/butyraldehyde
(mmol) × 100) of catalyst (SHC solids) and mesitylene as the
internal standard. After passing the N2 through the
headspace of the reaction system and setting a constant,
vigorous stirring rate, the reaction mixture was heated up to
the required temperature (80–130 °C). The progress of the
reaction was monitored by taking samples from the reaction
media at different intervals of time (2–22 h). For the recycling
experiments, the used catalyst was filtered, washed
thoroughly with a solvent (ether or methanol), dried at 200
°C, weighed and then applied in a subsequent run. The
conversion and yield were determined by 1H NMR (CDCl3).
The 1H spectra (400 MHz) and 13C spectra (100 MHz) were
application filed by Omya International related to the results
described in the manuscript.
Acknowledgements
The authors thank Dr. Craig DePorter, Dr. Daniel E. Gerard,
Dr. Nicole Russ and Sarah Gysin, from Omya International,
for their support. Omya International is kindly acknowledged
for financial support.
Notes and references
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All the other condensation reactions were carried out
similarly to the aldol condensation reaction. For the
Knoevenagel condensation reaction, the substrates employed
were benzaldehyde and malononitrile, similarly for the
Claisen–Schmidt condensation reaction, benzaldehyde and
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1
malononitrile: H NMR (400 MHz, CDCl3) δ (ppm): 7.55 (t, J =
7.6 Hz, 2H), 7.64 (t, J = 7.4 Hz, 1H), 7.78 (s, 1H), 7.91 (d, J =
7.3 Hz, 2H), 13C NMR (100 MHz, CDCl3); δ = 82.86, 112.48,
113.51, 129.60, 130.70, 134.54, 159.88.
Catal. Sci. Technol.
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