Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 25, 2024
Abstract
The
poly(lactic‐co‐glycolic
acid)
(PLGA)
with
completely
alternating
sequence
has
attracted
growing
attention
as
an
ideal
candidate
in
controlled
drug
delivery.
However,
the
approach
to
PLGA
remains
a
challenge.
Herein,
we
report
successful
synthesis
of
via
highly
regioselective
and
stereoselective
ring‐opening
polymerization.
chiral
(BisSalen)Al
catalyst
promoted
robust
polymerization
enantiopure
3‐methyl
glycolide
(MeG)
glycolyl
site
selectivity,
affording
regioselectivity
up
more
than
99
%.
Impressively,
exhibited
well‐defined
melting
temperature
T
m
143.1
°C.
Moreover,
stereocomplex
between
PLLGA
PDLGA
was
also
formed
improved
211.8
In
vitro
degradation
release
experiments
revealed
linear
behavior
PLGA,
which
can
be
used
carrier
for
mild
long‐acting
Meanwhile,
reason
high
investigated
through
control
DFT
calculation.
This
opens
door
providing
polymers.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(29)
Опубликована: Апрель 29, 2024
Abstract
Isotactic
polythioesters
(PTEs)
that
are
thioester
analogs
to
natural
polyhydroxyalkanoates
(PHAs)
have
attracted
growing
attention
due
their
distinct
properties.
However,
the
development
of
chemically
synthetic
methods
for
preparing
isotactic
PTEs
has
long
been
an
intricate
endeavour.
Herein,
we
report
successful
synthesis
perfectly
via
stereocontrolled
ring‐opening
polymerization.
This
binaphthalene‐salen
aluminium
(SalBinam‐Al)
catalyst
promoted
a
robust
polymerization
rac
‐α‐substituted‐β‐propiothiolactones
(
‐BTL
and
‐PTL)
with
highly
kinetic
resolution,
affording
P(BTL)
P(PTL)
M
n
up
276
kDa.
Impressively,
formed
supramolecular
stereocomplex
improved
thermal
property
T
m
=204
°C).
Ultimately,
this
resolution
enabled
facile
isolation
enantiopure
S
)‐BTL,
which
could
efficiently
convert
important
pharmaceutical
building
block
)‐2‐benzyl‐3‐mercapto‐propanoic
acid.
served
as
tough
ductile
material
comparable
commercialized
polyolefins.
system
allowed
access
PTEs,
establishing
powerful
platform
discovery
sustainable
plastics.
Angewandte Chemie,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 20, 2025
Abstract
Poly(lactic‐
co
‐glycolic
acid)
(PLGA)
has
been
widely
employed
for
various
biomedical
applications
owing
to
its
biodegradability
and
biocompatibility.
The
discovery
of
the
stereocomplex
formation
between
enantiomeric
alternating
PLGA
pairs
underscored
potential
as
high‐performance
biodegradable
materials
with
diverse
material
properties
biodegradability.
Herein,
we
have
established
a
regio‐
stereoselective
ring‐opening
polymerization
approach
synthesis
stereocomplexed
isoenriched
from
racemic
methyl‐glycolide
(
rac
‐MG).
high
sequence
tacticity
control
was
accomplished
by
an
optimized
enantiopure
scandium
catalyst
bearing
spiro‐salen
scaffold.
Varying
polymer
stereoregularity
P
m
0.4
0.91
led
transformation
resulting
amorphous
semicrystalline
materials.
Notably,
demonstrated
enhanced
melting
transition
temperature
T
up
191
°C)
crystallization
rate.
This
stereocontrolled
represented
versatile
preparation
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(37), С. 25852 - 25859
Опубликована: Сен. 3, 2024
Organocatalytic
ring-opening
polymerization
(ROP)
of
lactones
is
a
green
method
for
accessing
renewable
and
biodegradable
polyesters.
Developing
new
organocatalysts
with
high
activity
controllability
major
challenging
research
topic
in
this
field.
Here,
we
report
series
to
achieve
fast
controlled
ROP
lactones.
These
catalysts
incorporate
(thio)urea
alkoxide
one
molecule
act
as
initiators
the
ROP.
Such
enable
an
effective
intramolecular
activation
initiator/chain
end,
revealed
by
computational
studies,
resulting
higher
fewer
loads
than
existing
(thio)urea/alkoxide
binary
systems.
exhibit
ultrahigh
comparable
metal
complexes,
i.e.,
turnover
number
up
900
frequency
4860
min
Macromolecular Rapid Communications,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 22, 2024
Abstract
The
origin
of
stereocontrol
in
ring
opening
polymerization
(ROP)
racemic
lactide
(
rac
‐LA)
promoted
by
achiral
aluminium‐based
catalysts
has
been
explained
through
DFT
calculations
combined
with
a
molecular
descriptor
(%
V
Bur
)
and
the
activation
strain
model
(ASM‐NEDA)
analysis.
proposed
chain
end
control
(CEC)
suggests
that
ligand
framework
adopts
chiral
configuration
mimicking
enantiomorphic
site
(ESC)
while
also
incorporating
last
inserted
monomer
unit.
It
is
found
wrapping
mode
around
aluminium
centre
dictated
R
,
‐LA
S
‐LA).
A
good
correlation
experimental
data
achieved
only
when
accounting
for
dynamic
features
its
steric
influences,
as
highlighted
%
maps
ASM‐NEDA
Understanding
ESC
CEC
interplay
an
important
target
obtaining
stereoselective
ROP
synthesis
biodegradable
materials
tailored
properties.
Angewandte Chemie,
Год журнала:
2024,
Номер
136(29)
Опубликована: Апрель 29, 2024
Abstract
Isotactic
polythioesters
(PTEs)
that
are
thioester
analogs
to
natural
polyhydroxyalkanoates
(PHAs)
have
attracted
growing
attention
due
their
distinct
properties.
However,
the
development
of
chemically
synthetic
methods
for
preparing
isotactic
PTEs
has
long
been
an
intricate
endeavour.
Herein,
we
report
successful
synthesis
perfectly
via
stereocontrolled
ring‐opening
polymerization.
This
binaphthalene‐salen
aluminium
(SalBinam‐Al)
catalyst
promoted
a
robust
polymerization
rac
‐α‐substituted‐β‐propiothiolactones
(
‐BTL
and
‐PTL)
with
highly
kinetic
resolution,
affording
P(BTL)
P(PTL)
M
n
up
276
kDa.
Impressively,
formed
supramolecular
stereocomplex
improved
thermal
property
T
m
=204
°C).
Ultimately,
this
resolution
enabled
facile
isolation
enantiopure
S
)‐BTL,
which
could
efficiently
convert
important
pharmaceutical
building
block
)‐2‐benzyl‐3‐mercapto‐propanoic
acid.
served
as
tough
ductile
material
comparable
commercialized
polyolefins.
system
allowed
access
PTEs,
establishing
powerful
platform
discovery
sustainable
plastics.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 28, 2024
Stereospecific
alternating
copolymerization
of
different
chiral
cyclic
esters
is
one
feasible
approach
to
enrich
the
structural
diversity
copolyesters
and
tailor
their
properties.
However,
dramatically
reactivities
let
a
perfectly
stereospecific
polymerization
these
be
challenge,
thus
catalyst
required
balance
reactivities.
Herein,
remarkable
enantiomorphic
site
effect
on
chain
end
control
was
discovered
successfully
utilized
highly
reactive
S,
S-lactide
(S,
S-LA)
low
R,
R-ethylglycolide
(R,
R-EG)/R,
R-propylglycolide
R-PG)
during
heterospecific
copolymerization.
The
R-SalenAl
complex
can
increase
relative
reactivity
R-EG/R,
R-PG
suppress
that
S-LA,
then
sequence
copolymer
S-LA
achieved
(P
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 16, 2024
High-level
control
over
polymer
stereochemistry
leverages
the
fine-tuning
of
material
properties,
but
it
is
still
a
formidable
challenge
in
synthetic
chemistry.
Herein
we
prepared
new
class
salph
yttrium
catalysts
bearing
axially
chiral
binaphthyl
moieties
for
stereocontrolled
polymerization
