Macromolecular Rapid Communications,
Год журнала:
2024,
Номер
45(12)
Опубликована: Март 18, 2024
Abstract
Mesoionic
N
‐heterocyclic
olefins
(mNHOs)
have
recently
emerged
as
a
novel
class
of
highly
nucleophilic
and
super‐basic
σ‐donor
compounds.
Making
use
these
properties
in
synthetic
polymer
chemistry,
it
is
shown
that
combination
specific
mNHO
Mg‐based
Lewis
acid
(magnesium
bis(hexamethyldisilazide),
Mg(HMDS)
2
)
delivers
poly(propylene
oxide)
quantitative
yields
from
the
polymerization
corresponding
epoxide
(0.1
mol%
loading).
The
initiation
mechanism
involves
monomer
activation
by
direct
ring‐opening
attack
mNHO,
forming
zwitterionic
propagating
species.
Modulation
thereby
tool
to
impact
efficiency,
revealing
sterically
unencumbered
triazole‐derivative
particularly
useful.
joint
application
mNHOs
together
with
borane‐type
acids
also
outlined,
resulting
high
conversions
fast
kinetics.
Importantly,
while
molar
mass
distributions
remain
relatively
broad,
indicating
faster
propagation
than
initiation,
overall
masses
are
significantly
lower
found
case
regular
NHOs,
underlining
increased
nucleophilicity
ensuing
improved
efficiency
mNHOs.
Chemical Society Reviews,
Год журнала:
2024,
Номер
53(7), С. 3384 - 3456
Опубликована: Янв. 1, 2024
The
scientific
community
has
witnessed
extensive
developments
and
applications
of
organoboron
compounds
as
synthetic
elements
metal-free
catalysts
for
the
construction
small
molecules,
macromolecules,
functional
materials
over
last
two
decades.
This
review
highlights
achievements
organoboron-mediated
polymerizations
in
past
several
decades
alongside
mechanisms
underlying
these
transformations
from
standpoint
polymerization
mode.
Emphasis
is
placed
on
free
radical
polymerization,
Lewis
pair
ionic
(cationic
anionic)
polyhomologation.
Herein,
alkylborane/O
Russian Chemical Reviews,
Год журнала:
2024,
Номер
93(2), С. RCR5112 - RCR5112
Опубликована: Янв. 16, 2024
Carbon
dioxide
(CO<sub>2</sub>)
plays
a
vital
role
in
organic
and
polymer
chemistry
as
source
of
cheap
available
raw
material
for
the
synthesis
many
valuable
products,
including
materials
with
specified
set
properties,
solvent
chemical
reactions.
This
review
is
devoted
to
synthesis,
properties
applications
polycarbonates
obtained
by
copolymerization
CO<sub>2</sub>
epoxides,
hot
topic
that
has
aroused
great
interest
among
scientific
community
industry
representatives.
The
existing
data
on
catalytic
systems
used
are
analyzed
summarized,
depolymerization
polycarbonates,
which
key
aspect
recycling,
discussed,
information
systematized,
prospects
development
this
area
considered.<br>
Bibliography
—
438
references.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(27)
Опубликована: Апрель 22, 2024
Alkyl
borane
compounds-mediated
polymerizations
have
expanded
to
Lewis
pair
polymerization,
free
radical
ionic
ring-opening
and
polyhomologation.
The
bifunctional
organoborane
catalysts
that
contain
the
acid
ammonium
or
phosphonium
salt
in
one
molecule
demonstrated
superior
catalytic
performance
for
polymerization
of
epoxides
copolymerization
CO
International Journal of Molecular Sciences,
Год журнала:
2024,
Номер
25(20), С. 10946 - 10946
Опубликована: Окт. 11, 2024
A
comparative
study
of
the
copolymerization
racemic
propylene
oxide
(PO)
with
CO2
catalyzed
by
(salcy)CoX
(salcy
=
N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane;
X
perfluorobenzoate
(OBzF5)
or
2,4-dinitrophenoxy
(DNP))
in
presence
a
[PPN]Cl
([PPN]
bis(triphenylphosphine)iminium)
cocatalyst
is
performed
bulk
at
21
°C
and
2.5
MPa
pressure
CO2.
The
increase
nucleophilicity
an
attacking
anion
results
rate.
Racemic
provides
high
selectivity
copolymerization,
which
can
be
higher
than
99%,
living
polymerization
mechanism.
Poly(propylene
carbonate)
(PPC)
bimodal
molecular
weight
distribution
(MWD)
formed
throughout
copolymerization.
Both
modes
are
characterized
low
dispersity,
while
their
contribution
to
MWD
depends
on
nature
anion.
(salcy)CoDNP/[PPN]DNP
system
found
preferable
for
production
PPC
yield
selectivity.
Catalysts
combining
commercial
borane
Lewis
acids
and
potassium
acetate
complexes
achieve
the
selective
ring-opening
copolymerization
(ROCOP)
of
oxetanes
with
diverse
sulfur-containing
monomers.
