Topics in Current Chemistry (2019) 377:1
1 3
3.2.3 O‑Heterocycles
Furan (48) is already manufactured on an industrial scale via the decarbonylation
of furfural (6) over Pd‑based catalysts [96]. Zheng and colleagues evaluated the
gas‑phase continuous reaction on Pd nanoparticles supported on silicalite‑1 zeo‑
lite. A quantitative yield was achieved at 250–275 °C provided the wettability of
the zeolite was appropriately tuned. The enhanced performance was ascribed to
appropriate control of diffusion within the catalyst, where the adsorption of 6 and
by‑products and the desorption of 48 were favored. A prolonged run conducted
at 200 °C evidenced mild deactivation of the catalyst after 45 h time‑on‑stream
(Fig. 28). Catalyst coking was identified as the deactivation mechanism, but com‑
plete regeneration of catalytic activity was possible by calcination. Pd leaching or
sintering remained negligible [97].
Fig. 27 Continuous flow synthesis of 2‑methylpyrazine (47) from glycerol (3) and ethylenediamine (46)
Fig. 28 Gas‑phase continuous decarbonylation of furfural (6) into furan (48)
132
Reprinted from the journal
1 3
3.2.3 O‑Heterocycles
Furan (48) is already manufactured on an industrial scale via the decarbonylation
of furfural (6) over Pd‑based catalysts [96]. Zheng and colleagues evaluated the
gas‑phase continuous reaction on Pd nanoparticles supported on silicalite‑1 zeo‑
lite. A quantitative yield was achieved at 250–275 °C provided the wettability of
the zeolite was appropriately tuned. The enhanced performance was ascribed to
appropriate control of diffusion within the catalyst, where the adsorption of 6 and
by‑products and the desorption of 48 were favored. A prolonged run conducted
at 200 °C evidenced mild deactivation of the catalyst after 45 h time‑on‑stream
(Fig. 28). Catalyst coking was identified as the deactivation mechanism, but com‑
plete regeneration of catalytic activity was possible by calcination. Pd leaching or
sintering remained negligible [97].
Fig. 27 Continuous flow synthesis of 2‑methylpyrazine (47) from glycerol (3) and ethylenediamine (46)
Fig. 28 Gas‑phase continuous decarbonylation of furfural (6) into furan (48)
132
Reprinted from the journal