Organic & Biomolecular Chemistry,
Год журнала:
2023,
Номер
21(45), С. 9070 - 9075
Опубликована: Янв. 1, 2023
In
this
study,
we
show
the
effect
of
gem-dimethyl
substitution
at
four
benzylic
carbons
ring
on
internal
dynamics
two-station
[2]rotaxanes.
Such
structural
modification
polyamide
macrocycles
promotes
a
drastic
change
as
shown
by
variable-temperature
(VT)
1H
NMR
experiments.
We
determined
that
shuttling
rates
octamethylated
macrocycle
along
series
symmetrical
threads
were
significantly
faster
compared
to
non-substituted
ring.
This
was
particularly
pronounced
in
fumaramide-based
system,
which
rate
27
times
than
model
system.
Abstract
Rotaxanes
are
interlocked
molecules
that
consist
of
a
macrocycle
encircling
stoppered
thread.
The
ability
to
control
relative
component
positions
makes
rotaxanes
ideal
building
blocks
for
constructing
functional
and
responsive
molecular
machines.
Despite
the
potential
rotaxanes,
their
challenging
synthesis
limits
application.
One
approach
construct
is
use
an
active
template
synthesis,
where
reaction
forms
thread
accelerated
in
cavity
macrocycle.
An
emerging
method
exploits
crown
ether
macrocycles
accelerate
simple
organic
reactions
discussed
herein.
Crown
(CEATS)
permits
rapid
containing
wide
range
functionality.
Integrating
rotaxane
formation
with
chemical
networks
has
permitted
construction
simplification
will
facilitate
widespread
study
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(30)
Опубликована: Май 18, 2023
A
method
for
rotaxane
synthesis
by
enlargement
of
the
size
terminal
phenol
group
axle
component
aromatic
bromination
has
been
developed.
This
may
be
regarded
as
an
end-capping
strategy
involving
swelling
at
terminal.
The
advantages
present
include:
ready
availability
components
with
a
variety
precursors,
wide
product
scope
(19
examples
given
including
[3]rotaxane),
mild
conditions
process,
rich
potential
derivatization
brominated
rotaxanes,
and
possible
release
degradative
dethreading
thermally
stable
rotaxanes
under
basic
conditions.
ACS Applied Nano Materials,
Год журнала:
2024,
Номер
7(9), С. 10130 - 10136
Опубликована: Апрель 25, 2024
Herein,
we
designed
and
prepared
one
cobalt–nitrogen-doped
carbon
(Co–N/C)
nanoparticle
catalyst
with
a
metal–ligand
cooperation
(MLC)
effect,
where
the
MLC
concept
is
significant
in
catalytic
hydrogenation
reactions
but
limited
to
homogeneous
catalysts.
The
nanoparticles
Co–N/C
size
of
138–172
nm
catalyzed
diverse
organic
high
efficiency
selectivity,
including
reductive
formylation
nitroarenes
formic
acid,
C–N
coupling
between
alcohols
amines,
selective
quinolines
H2.
Detailed
spectroscopic
characterizations
controlled
experiments
revealed
that
Co–N
species
catalytically
active
site.
In
addition,
recycled
showed
outstanding
stability
reusability.
Therefore,
demonstrated
be
effective
heterogeneous
catalysts
as
well,
paving
way
discover
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(46)
Опубликована: Июль 30, 2024
Cyclodextrin-based
polyrotaxanes
(CD-PRs)
are
gaining
attention
for
their
dynamic
sliding
rings
along
the
polymer
axis,
enabling
various
applications
in
molecular
shuttles,
drug
delivery,
and
durable
polymers
with
slidable
cross-links.
However,
conventional
synthesis
of
CD-PRs
tunable
threading
ratios
is
typically
laborious,
time-consuming,
complicated,
which
limits
scalability
cost-effectiveness.
Herein,
we
highlight
great
potential
planetary
centrifugal
mixing,
a
process
that
significantly
accelerates
simplifies
initial
polypseudorotaxanes
(PPRs),
followed
by
thiol-ene
click
reaction
as
an
efficient
end-capping
PRs.
Notably,
PRs
synthesized
glutathione
(GSH)
reagent
metastable
state,
where
GSH
act
bumper
prevent
de-threading
α-CD
at
room
temperature.
Moreover,
rate
ring
can
be
precisely
controlled
heating,
preparation
over
wide
range.
The
developed
strategy
significance
to
CD-PRs,
thus
marking
significant
step
towards
practical
application
advanced
functional
materials
devices.
Organic & Biomolecular Chemistry,
Год журнала:
2023,
Номер
21(45), С. 9070 - 9075
Опубликована: Янв. 1, 2023
In
this
study,
we
show
the
effect
of
gem-dimethyl
substitution
at
four
benzylic
carbons
ring
on
internal
dynamics
two-station
[2]rotaxanes.
Such
structural
modification
polyamide
macrocycles
promotes
a
drastic
change
as
shown
by
variable-temperature
(VT)
1H
NMR
experiments.
We
determined
that
shuttling
rates
octamethylated
macrocycle
along
series
symmetrical
threads
were
significantly
faster
compared
to
non-substituted
ring.
This
was
particularly
pronounced
in
fumaramide-based
system,
which
rate
27
times
than
model
system.
