Angewandte Chemie,
Год журнала:
2024,
Номер
136(49)
Опубликована: Окт. 30, 2024
Abstract
While
functionalized
polyethylenes
(PEs)
exhibit
valuable
characteristics,
the
constraints
of
existing
synthetic
approaches
limit
variety
readily
incorporated
functionality.
New
methods
to
generate
PEs
are
required
afford
new
applications
this
common
material.
We
report
100
%
atom
economic
tantalum‐catalyzed
hydroaminoalkylation
vinyl‐terminated
polyethylene
(VTPE)
as
a
method
produce
amine‐terminated
PE.
VTPEs
with
molecular
weights
between
2200–16800
g/mol
successfully
aminated
using
solvent‐free
conditions.
Our
catalytic
system
is
efficient
for
installation
both
aromatic
and
aliphatic
amines,
can
be
carried
out
on
multigram
scale.
The
associating
amine
functional
groups
modified
material
properties,
measured
by
water
contact
angle,
differential
scanning
calorimetry
(DSC)
polymer
rheology.
basic
functionality
offers
opportunity
convert
inert
PE
into
stimuli‐responsive
materials,
such
that
protonation
affords
generation
antibacterial
films.
Organic & Biomolecular Chemistry,
Год журнала:
2024,
Номер
22(33), С. 6650 - 6664
Опубликована: Янв. 1, 2024
Titanium,
as
an
important
transition
metal,
has
garnered
extensive
attention
in
both
industry
and
academia
due
to
its
excellent
mechanical
properties,
corrosion
resistance,
unique
reactivity
organic
synthesis.
In
the
field
of
photocatalysis,
titanium-based
compounds
such
titanium
dioxide
(TiO
Cell Reports Physical Science,
Год журнала:
2023,
Номер
4(9), С. 101548 - 101548
Опубликована: Авг. 21, 2023
This
perspective
provides
an
entry-level
conversation
concerning
base
metal
catalysis
as
a
green
and
sustainable
solution
in
industrial
academic
contexts.
We
establish
definition
of
"base
metal,"
challenging
readers
to
consider
the
ethical
implications
sourcing.
explore
what
it
means
be
"sustainable"
provide
information
on
current
efforts
synthetic
chemistry.
examples
catalytic
trends
transformations
popular
fields
such
cross-coupling
small-molecule
conversion,
highlighting
relevant
systems.
Finally,
we
social
context—for
example,
decisions
related
catalyst
development
are
often
driven
by
factors
including
costliness,
safety,
adoptability
(whether
society
will
accept
its
usage),
performance.
How
do
move
forefront?
Is
concerned
if
materials
fabricated
from
cheaper
more
abundant
sources?
does
chemistry
community
guide
this
knowledge
translation?
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(42), С. 22871 - 22877
Опубликована: Окт. 11, 2023
Early
transition
metal-catalyzed
hydroaminoalkylation
is
a
powerful
single-step
method
to
selectively
add
amines
polybutadienes,
offering
an
efficient
strategy
access
amine-functionalized
polyolefins.
Aryl
and
alkyl
secondary
were
used
with
tantalum
catalyst
functionalize
both
28
wt%
(PBD13)
70
(PBD50)
1,2-polybutadiene
polymers.
The
degree
of
amination
was
controlled
by
modifying
amine
loading
in
small-
multigram-scale
reactions.
vinyl
groups
aminated
ease,
unexpectedly
the
challenging
internal
alkenes
1,4-polybutadiene
unit
observed.
This
unanticipated
reactivity
proposed
be
due
directing
group
effect.
hypothesis
supported
small-molecule
model
substrates,
which
also
showed
directed
alkene
amination.
Increasing
degrees
resulted
materials
dramatically
higher
tunable
glass
temperature
(Tg)
values,
dynamic
cross-linking
accessible
hydrogen-bonding,
amine-containing
materials.
Primary
polybutadiene
prepared,
demonstrating
that
broad
new
class
polyolefins
can
accessed
postpolymerization
hydroaminoalkylation.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 8, 2025
Catalyst
and
substrate
steric
electronic
features
that
influence
regioselectivity
in
hydroaminoalkylation
were
leveraged
to
develop
a
synthetic
approach
for
the
selective
synthesis
of
β-amino
acids.
An
situ
generated
tantalum-ureate
catalyst
was
used
prepare
18
γ-silylated
amines
up
93%
yield
from
internal
silylated
alkenes.
β-Amino
silane
regioisomer
production
rarely
observed,
making
this
work
one
few
examples
highly
regioselective
with
unsymmetric
These
γ-amino
silanes
converted
alcohols
modified
Tamao-Fleming
oxidation
strategy
followed
by
two
additional
steps
acids,
including
key
fragment
anticancer
drug
candidate
Ipatasertib.
ACS Sustainable Chemistry & Engineering,
Год журнала:
2023,
Номер
11(49), С. 17355 - 17370
Опубликована: Ноя. 27, 2023
Green
chemistry
is
part
of
the
chemical
industry’s
response
to
calls
for
improved
environmental
responsibility.
It
also
one
several
paths
redemption
from
its
erstwhile
infamous
reputation
as
most
polluting
sectors.
We
studied
impacts
implementing
some
these
principles
on
production
methyl
methacrylate
(MMA),
monomer
PMMA
popularly
known
acrylic
glass.
This
study
used
life
cycle
assessment
(LCA)
methodology
compare
potential
three
different
approaches
MMA.
Two
are
established
industrial
pathways:
acetocyanohydrin
process
(ACH-MMA)
and
Alpha
Lucite
(AL-MMA),
which
represent
conventional
a
fast-rising
route,
respectively,
while
third,
in
situ
formaldehyde
(inFAL-MMA)
lab-based
process.
The
scenarios
were
evaluated
using
cumulative
energy
demand
(CED)
ReCiPe
2016
impact
methods.
results
obtained
highlighted
hotspots
that
can
benefit
improvements
careful
material
source
selection.
underscored
AL-MMA
record
significant
performance
by
reducing
overall
resource
intensity
inFAL-MMA
synthesis
was
adjudged
be
evolved
alternatives
with
respect
green
principles;
hence,
sought
investigate
possible
gains
attributable
this.
Some
limitations
uncovered
during
necessitated
use
an
additional
tool
further
risk.
Thus,
GREEN
MOTION
adopted
examine
this
relationship.
Overall,
areas
examined.
confirmed
importance
factors
like
data
quality,
degree
optimization,
source,
others
LCA.
Abstract
The
prominence
of
saturated
N-heterocycle
motifs
in
pharmaceuticals
is
undeniable.
Challenges
associated
with
the
alkylation
scaffolds
to
efficiently
access
new
drug
analogues
are
hampered
by
synthetically
laborious
routes.
Stereocontrolled
alkyl-substitutions
onto
N-heterocycles
particularly
difficult
high
yields
traditional
synthetic
methods.
Alternatively,
C–H
bond
functionalization
provides
a
and
powerful
avenue
directly
selectively
functionalizing/alkylating/
arylating
abundantly
available
bonds
N-heterocycles.
This
review
highlights
complementary
methods
for
activating
functionalizing
chemo-,
regio-,
or
stereoselectively
alkylated
products.
challenge
has
required
catalyst
development
useful
N-heterocyclic
building
blocks
late-stage
functionalization.
Early
transition
metal,
late
photoredox,
electrochemical
discussed.
selective
α,
β,
γ
form
C–C,
C–N,
C–O,
C–B
presented.
1
Introduction
2
Transition
Metal
Catalyzed
α-Alkylation
3
Late
α-Functionalization
4
Photoredox-Catalyzed
5
Electrochemical
6
Functionalization
β
Bonds
7
Conclusions/Outlook
Macromolecular Rapid Communications,
Год журнала:
2024,
Номер
45(23)
Опубликована: Окт. 1, 2024
Polymerization
of
primary
amine-containing
monomers
is
challenging
because
the
amine
inhibits
polymerization
catalyst
activity.
An
alternative
approach
to
access
functionalized
polymers
postpolymerization
modification.
To
this
end,
hydroaminoalkylation
vinyl-terminated
polyolefins
with
N-(trimethylsilyl)benzylamine
used
prepare
amine-terminated
polyolefins,
free
substituent
being
revealed
upon
hydrolytic
work
up.
These
materials
are
spectroscopically
characterized,
and
an
investigation
thermal
properties
by
differential
scanning
calorimetry
thermogravimetric
analysis
completed.
results
show
that
increases
glass
transition
temperature
improves
stability.
The
reactive
functionality
in
photo-oxidative
dimerization
demonstrate
how
elusive
can
be
applied
oligomer
valorization.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(49)
Опубликована: Окт. 30, 2024
Abstract
While
functionalized
polyethylenes
(PEs)
exhibit
valuable
characteristics,
the
constraints
of
existing
synthetic
approaches
limit
variety
readily
incorporated
functionality.
New
methods
to
generate
PEs
are
required
afford
new
applications
this
common
material.
We
report
100
%
atom
economic
tantalum‐catalyzed
hydroaminoalkylation
vinyl‐terminated
polyethylene
(VTPE)
as
a
method
produce
amine‐terminated
PE.
VTPEs
with
molecular
weights
between
2200–16800
g/mol
successfully
aminated
using
solvent‐free
conditions.
Our
catalytic
system
is
efficient
for
installation
both
aromatic
and
aliphatic
amines,
can
be
carried
out
on
multigram
scale.
The
associating
amine
functional
groups
modified
material
properties,
measured
by
water
contact
angle,
differential
scanning
calorimetry
(DSC)
polymer
rheology.
basic
functionality
offers
opportunity
convert
inert
PE
into
stimuli‐responsive
materials,
such
that
protonation
affords
generation
antibacterial
films.
