Page 177 - CW E-Magazine (28-5-2024)

Special Report

Catalytic distil- Efficient and scalable asym-
lation dehy- metric total synthesis of (-)
drogenation of emetine (E)
perhydro-ben-
zyl toluene M. Yamada et al have reported the title
[Carriers for H process with pharma grade E. Here the
starting chemical is 2 (homoveratryl-
2
transport are under amine) and 13 steps are involved and is
study and dibenzyl chromatography-free process. Catalytic
toluene (DBT) is a asymmetric allylation and an industrial
strong candidate.]
deoxygenation of an aliphatic com-
Q. Wang et al have pound are involved. The overall yield
studied the reaction was 12% and HPLC purity was 93.2%.
kinetics, modelling (Org. Proc. Res. Dev., 2023; DOI:
Ketonisation of propionic acid and process analysis of the title re- 10.1021/acs.oprd.2c00355).
(PA) over TS-1 and Ti-beta action. This required a study of the
zeolites vapor-liquid equilibrium. This study Fundamentals of unanticipa-
brings out an optimal degree of de- ted efficiency of Gd O -based
2
3
Z. Yang et al have studied the title hydrogenation, namely 0.8, in the title catalysts in oxidative coupling
reaction of industrial importance to process and is more economic than of methane
understand the reaction mechanism and full dehydrogenation. (Chem. Eng.
effects of pore topology and hydropho- Jl., 2024, 482, 15 Feb., 148591; DOI: The oxidative coupling of CH conti-
4
bicity. TS-1 gave higher activity, selec- 10.1016/j.cej.2024.148591). nues to attract a lot of attention due to the
tivity, stability, and had greater resis- wide availability of natural gas. K. Wu
tance to H O than Ti-beta. This paper Current state and future pros- et al have reported about 90% selecti-
2
has given insight into the ketonisation pects of liquid metal catalysis vity at 11% CH conversion with Gd O -
4
2
3
mechanism, and authors have sugges- (LMC) based catalysts at 700 C, using N O as
o
2
ted that moderate pore size and hydro- the oxidant. (Angew. Chem. Intl. Ed.;
phobic property of the catalyst pro- S.S. Fatima et al have referred to the DOI: 10.1002/anie.202319192).
motes ketonisation. (J. Catalysis, 2024, recently gained attention for LMC, which
429, January, 115247; DOI: 10.1016/j. seem to offer exciting sets of features, Enantioselective intramole-
jcat.2023.115247). strengths and challenges. These authors cular α-arylation of benzylamine
have provided insights into LMC in an derivatives: Synthesis of a pre-
O vacancy of Pt/CeO enabled already burgeoning field of catalysis. cursor to Levocetirizine
2
2
low-temperature H generation Recent advances in the chemistry of
2
from methanol and water liquid metal are covered and indication R.K Saunthwal et al have reported a
is given for the class of reactions which practical, transition metal-free method to
[H generation via reforming of CH OH may benefit from such catalysis. (Nature get the title compound: Enantioselective
2
3
with steam is commercially practiced Catalysis, 2023, 6, 1131-1139). lithiation of N’-aryl-N-benzyl-N-iso-
on modest scale.]
Q. Guo et al have demonstrated that
Pt nanoparticles supported on porous
nanorods of CeO with abundant oxygen
2
vacancies (Pt/PN-CeO ) allowed the
3
efficient H generation even at below
2
60 C. CO generation is suppressed.
o
One mole of CH OH and one equi-
3
valent of H O generates three equi-
2
valents of H . (J. Catalysis, 2024, 430,
2
February, 115309; DOI: 10.1016/j.
jcat.2024.115309).
Chemical Weekly May 28, 2024 177
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