Kumada
cross
coupling
reaction
is
a
useful
to
produce
biphenyls,
where
nickel
and
copper
have
been
widely
investigated
as
catalysts
but
mainly
homogeneous
ones.
In
this
study,
we
ultrasound-assisted-Kumada
over
the
heterogeneous
in
which
Ni2+,
Cu2+,
or
both
was
immobilized
on
aminopropylsilane-functionalized-SiO2-TiO2
prepared
presence
of
cetyltrimethylammonium
bromide
(CTAB).
The
CTAB
effectively
prevented
particle
growth
therefore
SiO2-TiO2
fine
particles
with
high
surface
area
(502
m2
g-1)
were
formed.
Ni2+-immobilized
catalyst
showed
catalytic
activity
for
wide
variety
substrates
reusable
three
times.
Performing
under
ultrasound
irradiation
very
effective
significantly
accelerating
rate
compared
conventional
mechanical
method.
contrast
Cu2+
deposited
support
crystalline
Cu(OH)2
resulting
Cu2+-Ni2+
less
active
stable
conditions.
Nature Synthesis,
Год журнала:
2024,
Номер
3(6), С. 744 - 751
Опубликована: Апрель 16, 2024
Abstract
The
synthesis
of
monolayer
gold
has
so
far
been
limited
to
free-standing
several-atoms-thick
layers,
or
monolayers
confined
on
inside
templates.
Here
we
report
the
exfoliation
single-atom-thick
achieved
through
wet-chemically
etching
away
Ti
3
C
2
from
nanolaminated
AuC
,
initially
formed
by
substituting
Si
in
SiC
with
Au.
is
a
renown
MAX
phase,
where
M
transition
metal,
A
group
element,
and
X
N.
Our
developed
synthetic
route
facile,
scalable
hydrofluoric
acid-free
method.
two-dimensional
layers
are
termed
goldene.
Goldene
roughly
9%
lattice
contraction
compared
bulk
observed
electron
microscopy.
While
ab
initio
molecular
dynamics
simulations
show
that
goldene
inherently
stable,
experiments
some
curling
agglomeration,
which
can
be
mitigated
surfactants.
X-ray
photoelectron
spectroscopy
reveals
an
Au
4
f
binding
energy
increase
0.88
eV.
Prospects
for
preparing
other
non-van
der
Waals
Au-intercalated
phases,
including
developing
schemes,
presented.
ACS Catalysis,
Год журнала:
2023,
Номер
13(10), С. 6787 - 6794
Опубликована: Май 3, 2023
Efficient
deoxygenative
silylation
of
C(sp3)–O
bonds
with
hydrosilanes
by
supported
Au
catalysts
is
described.
Gold
nanoparticles
on
TiO2
enabled
various
to
be
used
as
sources
silyl
groups
in
C–Si
cross-coupling
reactions.
A
variety
alkyl
acetates
and
propargyl
carbonates
participated
the
Au-catalyzed
reactions
furnish
corresponding
allenylsilanes
high
yields.
In
addition,
Au/TiO2
was
also
effective
for
ring-opening
cyclic
ethers.
detailed
mechanistic
investigation
corroborated
that
title
reaction
involves
formation
radical
intermediates,
cooperation
single-electron
transfer
Lewis
acid
sites
at
surface
metal
oxides
responsible
unusual
reactivity
specific
C(sp3)–Si
bond
formation.
Organic Letters,
Год журнала:
2024,
Номер
26(15), С. 2902 - 2907
Опубликована: Апрель 4, 2024
We
report
herein
that
supported
gold
catalysts
efficiently
promote
the
borylation
of
stable
C(sp3)–O
bonds
alkyl
esters.
The
use
a
disilane
as
an
electron
source
and
nanoparticles
single-electron
transfer
catalyst
is
key
to
generating
radicals
via
homolysis
bonds,
thereby
enabling
cross-coupling
between
bis(pinacolato)diboron
linear
cyclic
esters
afford
diverse
boronates.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(38)
Опубликована: Июнь 18, 2024
Described
herein
is
a
dirhodium(II)-catalyzed
silylation
of
propargyl
esters
with
hydrosilanes,
using
tertiary
amines
as
axial
ligands.
By
adopting
this
strategy,
range
versatile
and
useful
allenylsilanes
can
be
achieved
good
yields.
This
reaction
not
only
represents
S
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(40), С. 27528 - 27541
Опубликована: Авг. 29, 2024
The
cooperation
of
multiple
catalytic
components
is
a
powerful
tool
for
intermolecular
bond
formation,
specifically,
cross-coupling
reactions.
Supported
metal
catalysts
have
interfacial
sites
between
nanoparticles
and
their
supports
where
elements
can
work
in
to
efficiently
promote
Hence,
the
establishment
novel
guidelines
designing
active
supported
indispensable
heterogeneous
which
enable
efficient
In
this
article,
we
performed
kinetic
theoretical
studies
elucidate
effect
metal-support
borylation
C-O
bonds
by
gold
revealed
that
Lewis
acid
density
determined
number
at
(NPs)
surface
cooperation.
Furthermore,
DFT
calculations
strong
adsorption
diborons
interface
Au
NPs
decrease
LUMO
level
adsorbed
diboron
were
responsible
borylation.
with
optimized
metal-metal
oxide
sites,
namely,
Au/α-Fe
The Journal of Physical Chemistry C,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 10, 2025
Plastic
waste
is
a
major
environmental
issue;
converting
it
directly
into
valuable
chemicals
by
using
catalysts
promising
alternative
to
plastic
recycling.
Here,
we
report
the
selective
catalytic
cracking
of
polypropylene
(PP),
typical
commodity
plastic,
high-value
light
olefins
(C2–C5),
below
pyrolytic
temperature
(290
°C)
and
without
external
hydrogen
supply,
zeolite
catalysts.
Among
H+-form
zeolites
with
different
structures,
HMFI
showed
highest
yields
hydrocarbons
which
(C2–C5)
were
products.
The
HMFI-catalyzed
PP
conversion
was
applicable
upcycling
model
waste,
resulting
in
61.9%
hydrocarbon
yield.
results
situ
IR
experiments
small
amount
Brønsted
acid
sites
suggested
that
on
surface
are
indispensable
for
posited
be
active
short-chain
(oligomeric)
species
as
intermediate
Density
functional
theory
analyses
conducted
determine
plausible
reaction
pathways
adopting
2,4-dimethylheptene
shortest
unit
oligomeric
species.
obtained
show
β-scission
isobutene
propylene
(or
propyl
alkoxide
group)
via
carbocation
intermediates
an
activation
energy
118
kJ
mol–1.
Operando
UV–vis
under
conditions,
combined
ex
1H
NMR
13C
spent
catalyst,
some
further
converted
or
heavy
aromatics
(coke
deposit),
probably
carbenium
ion
The
transition
metal-catalyzed
coupling
reaction
has
renewed
the
role
of
ester
as
an
electrophilic
partner.
In
this
context,
we
describe
a
synergistic
Ni/Zn-catalyzed
formal
transesterification
but-3-enyl
esters
with
tetrahydrofuran
and
alkyl
iodides
to
give
4-alkoxylbutyl
esters.
aromatic
aliphatic
are
both
competent
electrophiles
thus
broaden
substrate
scope
in
reactions,
because
previously
reported
work
were
strictly
limited
ones.
Mechanistic
studies
reveal
that
C(acyl)-O
bond
or
even
more
inert
C(alkyl)-O
could
be
cleaved
under
nickel
catalysis.
Two
catalytic
cycles
proposed,
which
represent
new
pathway
versus
traditional
transesterification.
