The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(22), С. 16510 - 16521
Опубликована: Ноя. 4, 2024
Aliphatic
allylic
amines
are
present
in
a
large
number
of
complex
and
pharmaceutically
relevant
molecules.
The
direct
amination
electrophiles
serves
as
the
most
common
method
toward
preparation
these
motifs.
However,
use
feedstock
reaction
components
(allyl
alcohol
aliphatic
amine)
transformations
remains
great
challenge.
Such
challenge
primarily
stems
from
high
Lewis
basicity
steric
hindrance
amines,
addition
to
low
reactivity
alcohols.
Herein,
we
report
general
solution
challenges.
developed
protocol
allows
an
efficient
allyl
alcohols
with
sterically
bulky
presence
inexpensive
earth-abundant
molybdenum
complex.
This
simple
economic
also
enables
regioselective
branched
amination;
practicality
was
shown
efficient,
scaled-up
synthesis
several
drugs.
Green Chemistry,
Год журнала:
2023,
Номер
25(9), С. 3592 - 3605
Опубликована: Янв. 1, 2023
Nanoporous
poly(ionic
liquid)s
with
both
great
porosities
and
high
IL
contents
are
prepared
through
a
two-step
synthetic
strategy,
serving
as
efficient
heterogeneous
catalysts
for
CO
2
cycloaddition
epoxides
under
mild
conditions.
Green Chemistry,
Год журнала:
2022,
Номер
24(18), С. 7194 - 7207
Опубликована: Янв. 1, 2022
Bifunctional
imidazolium-based
ILs
possessing
multipoint
HBDs
efficiently
catalyze
the
cycloaddition
reaction
of
CO
2
and
epoxides
at
a
significantly
low
loading
to
form
cyclic
carbonates
with
wide
scope
substrates.
ChemSusChem,
Год журнала:
2020,
Номер
14(1), С. 363 - 372
Опубликована: Окт. 17, 2020
Abstract
A
series
of
hydroxy‐functionalized
phosphonium
salts
were
studied
as
bifunctional
catalysts
for
the
conversion
CO
2
with
epoxides
under
mild
and
solvent‐free
conditions.
The
reaction
in
presence
a
phenol‐based
iodide
proceeded
via
first
order
rection
kinetic
respect
to
substrate.
Notably,
contrast
aliphatic
analogue,
catalyst
showed
no
product
inhibition.
temperature
dependence
rate
was
investigated,
activation
energy
model
determined
from
an
Arrhenius‐plot
(
E
=39.6
kJ
mol
−1
).
substrate
scope
also
evaluated.
Under
optimized
conditions,
20
terminal
converted
at
room
corresponding
cyclic
carbonates,
which
isolated
yields
up
99
%.
is
easily
scalable
performed
on
scale
50
g
Moreover,
this
method
applied
synthesis
antitussive
agent
dropropizine
starting
epichlorohydrin
phenylpiperazine.
Furthermore,
DFT
calculations
rationalize
mechanism
high
efficiency
catalyst.
calculation
confirmed
epoxide
hydrogen
bonding
salt,
facilitates
ring‐opening
step.
effective
Gibbs
barrier
regarding
step
97
bromide
72
explains
difference
activity.
Abstract
A
series
of
dihydroxybenzene‐derived
ILs
was
synthesised
via
a
halide‐free,
eco‐friendly
methodology
and
fully
characterized.
Their
activity
as
single
component
catalyst
towards
synthesis
cyclic
organic
carbonates
(COCs)
CO
2
insertion
into
terminal
epoxides
evaluated,
observing
that
methyltrioctylammonium
hydroquinolate,
[N
1888
][HYD],
the
most
active
in
proposed
optimized
conditions
([N
][HYD]
10
%
mol,
T=120
°C,
t=6
h,
p
0
(CO
)=2.0
MPa,
12
examples,
conversion
>99
%,
yield
up
to
98
%).
Interestingly,
also
an
for
reactions
with
cyclohexene
oxide
(CHO),
formation
both
COC
polycarbonate
product.
It
is
)≥1.0
catalytically
species
hemicarbonate
derivative
hydroquinolate
anion,
epoxide
ring
opening
unusual
hemicarbonate‐alkoxide
pathway.
Chinese Journal of Chemistry,
Год журнала:
2024,
Номер
42(14), С. 1571 - 1581
Опубликована: Март 15, 2024
Comprehensive
Summary
Eight
zwitterionic
rare
earth
metal
complexes
stabilized
by
amino‐bridged
tris(phenolato)
ligands
bearing
quaternary
ammonium
side‐arms
were
synthesized
and
characterized.
These
used
as
single‐component
catalysts
for
the
cycloaddition
of
CO
2
epoxides,
their
catalytic
activities
are
obviously
higher
than
those
binary
analogues.
Further
studies
revealed
that
halide
anions
(Cl
–
,
Br
I
)
influenced
activity,
lanthanum
complex
iodide
anion
showed
highest
activity
this
addition
reaction.
A
variety
mono‐substituted
epoxides
converted
to
cyclic
carbonates
in
good
excellent
yields
(55%—99%)
with
high
selectivity
(>
99%)
at
30
°C
1
bar
whereas
internal
required
both
reaction
temperatures
(60—120
°C)
catalyst
loading
(2
mol%)
yields.
The
was
recyclable
four
times
without
noticeable
loss
activity.
Based
on
results
kinetic
situ
IR
reactions,
a
plausible
mechanism
proposed.
Journal of CO2 Utilization,
Год журнала:
2023,
Номер
79, С. 102659 - 102659
Опубликована: Дек. 30, 2023
The
coupling
reaction
of
carbon
dioxide
and
highly-substituted
epoxides
derived
from
renewable
resources
such
as
fatty
acids
waste
vegetable
oils
(cooking
olive
sunflower)
leads
to
the
synthesis
new
bio-derived
cyclic
carbonates
using
efficient
metal-free
bifunctional
organocatalysts
under
mild
solvent-free
conditions.
Once
biobased
sources
were
synthesized,
design
non-isocyanate
polyurethanes
(NIPUs)
with
different
chemical
structures
was
investigated
by
their
a
broad
substrate
scope
diamines.
NIPUs
materials
characterized
spectroscopic
techniques
(NMR
IR)
molecular
weights
polydispersities
determined
GPC
studies.
Finally,
thermal
properties
polymers
studied
DSC
TGA
analyses.
Inorganic Chemistry Frontiers,
Год журнала:
2021,
Номер
8(16), С. 3871 - 3884
Опубликована: Янв. 1, 2021
An
octahedral
cobalt(iii)
complex
based
on
cheap
1,2-phenylenediamine
operates
as
an
efficient
bifunctional
hydrogen
bond
donor
catalyst
in
cycloaddition
of
epoxides
with
CO2
under
ambient
conditions
and
solvent-
co-catalyst-free
conditions.
Inorganic Chemistry Frontiers,
Год журнала:
2022,
Номер
9(12), С. 2969 - 2979
Опубликована: Янв. 1, 2022
Lanthanum
complex
1/TBAI
is
the
first
catalyst
to
achieve
cycloaddition
of
1,2-disubstituted
epoxides
with
1
bar
CO
2
at
room
temperature.
A
DFT
study
discloses
that
poly(phenolato)
ligand
plays
a
key
role
in
product
dissociation
step.
