Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(24)
Опубликована: Март 25, 2022
The
synthesis
of
primary
anilines
via
sustainable
methods
remains
a
challenge
in
organic
synthesis.
We
report
photocatalytic
protocol
for
the
selective
cross-coupling
wide
range
aryl/heteroaryl
halides
with
sodium
azide
using
photocatalyst
powder
consisting
nickel(II)
deposited
on
mesoporous
carbon
nitride
(Ni-mpg-CN
Journal of the American Chemical Society,
Год журнала:
2022,
Номер
144(14), С. 6516 - 6531
Опубликована: Март 30, 2022
Ni
2,2'-bipyridine
(bpy)
complexes
are
commonly
employed
photoredox
catalysts
of
bond-forming
reactions
in
organic
chemistry.
However,
the
mechanisms
by
which
they
operate
still
under
investigation.
One
potential
mode
catalysis
is
via
entry
into
Ni(I)/Ni(III)
cycles,
can
be
made
possible
light-induced,
excited-state
Ni(II)-C
bond
homolysis.
Here,
we
report
experimental
and
computational
analyses
a
library
Ni(II)-bpy
aryl
halide
complexes,
Ni(Rbpy)(R'Ph)Cl
(R
=
MeO,
t-Bu,
H,
MeOOC;
R'
CH3,
OMe,
F,
CF3),
to
illuminate
mechanism
At
given
excitation
wavelengths,
photochemical
homolysis
rate
constants
span
2
orders
magnitude
across
these
structures
correlate
linearly
with
Hammett
parameters
both
bpy
ligands,
reflecting
structural
control
over
key
metal-to-ligand
charge-transfer
(MLCT)
ligand-to-metal
(LMCT)
energy
surfaces
(PESs).
Temperature-
wavelength-dependent
investigations
reveal
moderate
barriers
(ΔH‡
∼
4
kcal
mol-1)
minimum
threshold
(∼55
mol-1,
525
nm),
respectively.
Correlations
electronic
structure
calculations
further
support
repulsive
triplet
PESs
featuring
critical
aryl-to-Ni
LMCT
lead
rupture.
Structural
provides
rational
approach
utilize
photonic
leverage
processes
synthetic
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(18), С. 9988 - 9993
Опубликована: Май 1, 2023
Herein,
a
regioselective,
late-stage
two-step
arene
halogenation
method
is
reported.
We
propose
how
unusual
Ni(I)/(III)
catalysis
enabled
by
combination
of
aryl
thianthrenium
and
Ni
redox
properties
that
hitherto
unachieved
with
other
(pseudo)halides.
The
catalyst
accessed
in
situ
from
inexpensive
NiCl2·6(H2O)
zinc
without
the
need
supporting
ligands.
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(15), С. 8689 - 8699
Опубликована: Апрель 4, 2023
While
the
oxidative
addition
of
Ni(I)
to
aryl
iodides
has
been
commonly
proposed
in
catalytic
methods,
an
in-depth
mechanistic
understanding
this
fundamental
process
is
still
lacking.
Herein,
we
describe
a
detailed
study
using
electroanalytical
and
statistical
modeling
techniques.
Electroanalytical
techniques
allowed
rapid
measurement
rates
for
diverse
set
iodide
substrates
four
classes
catalytically
relevant
complexes
(Ni(MeBPy),
Ni(MePhen),
Ni(Terpy),
Ni(BPP)).
With
>200
experimental
rate
measurements,
were
able
identify
essential
electronic
steric
factors
impacting
through
multivariate
linear
regression
models.
This
led
classification
mechanisms,
either
three-center
concerted
or
halogen-atom
abstraction
pathway
based
on
ligand
type.
A
global
heat
map
predicted
was
created
shown
applicable
better
reaction
outcome
case
Ni-catalyzed
coupling
reaction.
ACS Catalysis,
Год журнала:
2024,
Номер
14(11), С. 9055 - 9076
Опубликована: Май 29, 2024
Metallaphotoredox
catalysis
can
unlock
useful
pathways
for
transforming
organic
reactants
into
desirable
products,
largely
due
to
the
conversion
of
photon
energy
chemical
potential
drive
redox
and
bond
transformation
processes.
Despite
importance
these
processes
cross-coupling
reactions
other
transformations,
their
mechanistic
details
are
only
superficially
understood.
In
this
review,
we
have
provided
a
detailed
summary
various
photoredox
mechanisms
that
been
proposed
date
Ni-bipyridine
(bpy)
complexes,
focusing
separately
on
photosensitized
direct
excitation
reaction
By
highlighting
multiple
key
findings,
depict
how
mechanisms,
which
ultimately
define
substrate
scope,
themselves
defined
by
ground-
excited-state
geometric
electronic
structures
Ni-based
intermediates.
We
further
identify
knowledge
gaps
motivate
future
studies
development
synergistic
research
approaches
spanning
physical,
organic,
inorganic
chemistry
communities.
Nature Catalysis,
Год журнала:
2024,
Номер
7(6), С. 733 - 741
Опубликована: Май 7, 2024
Abstract
Nickel
photoredox
catalysis
has
resulted
in
a
rich
development
of
transition-metal-catalysed
transformations
for
carbon–heteroatom
bond
formation.
By
harnessing
light
energy,
the
transition
metal
can
attain
oxidation
states
that
are
difficult
to
achieve
through
thermal
chemistry
catalytic
manifold.
For
example,
nickel
reactions
have
been
reported
both
synthesis
anilines
and
aryl
ethers
from
aryl(pseudo)halides.
However,
oxidative
addition
simple
systems
is
often
sluggish
absence
special,
electron-rich
ligands,
leading
catalyst
decomposition.
Electron-rich
electrophiles
therefore
currently
fall
outside
scope
many
field.
Here
we
provide
conceptual
solution
this
problem
demonstrate
nickel-catalysed
C–heteroatom
bond-forming
arylthianthrenium
salts,
including
amination,
oxygenation,
sulfuration
halogenation.
Because
redox
properties
salts
primarily
dictated
by
thianthrenium,
highly
donors
be
unlocked
using
NiCl
2
under
irradiation
form
desired
C‒heteroatom
bonds.
ACS Catalysis,
Год журнала:
2025,
Номер
unknown, С. 4665 - 4680
Опубликована: Март 5, 2025
Transition
metal
catalysis
is
an
indispensable
tool
for
organic
synthesis
that
has
been
harnessed,
modulated,
and
perfected
many
decades
by
careful
selection
of
centers
ligands,
giving
rise
to
synthetic
methods
with
unparalleled
efficiency
chemoselectivity.
Recent
developments
have
demonstrated
how
light
irradiation
can
also
be
recruited
as
a
powerful
dramatically
alter
the
outcome
catalytic
reactions,
providing
access
innovative
pathways
remarkable
potential.
In
this
context,
adoption
photochemical
conditions
mainstream
strategy
drive
reactions
unveiled
exciting
opportunities
exploit
rich
excited-state
framework
transition
metals
applications.
This
Perspective
examines
advances
in
application
complexes
standalone
photocatalysts,
exploiting
innate
reactivity
their
excited
states
beyond
common
use
photoredox
catalysts.
An
account
relevant
examples
dissected
provide
discussion
on
electronic
reorganization,
orbitals
involved,
associated
different
types
states.
analysis
aims
practitioners
fundamental
principles
guiding
strategies
understand,
design,
apply
light-activation
homogeneous
synthesis.
ACS Catalysis,
Год журнала:
2020,
Номер
10(24), С. 15178 - 15185
Опубликована: Дек. 9, 2020
Light-driven
dual
catalysis
that
combines
photosensitizers
and
transition-metal
complexes
has
become
a
powerful
approach
for
diverse
cross-coupling
reactions.
Heterogeneous
photocatalysts
recently
have
gained
growing
attention
to
build
such
catalytic
system
controllable
reaction
kinetics
enhanced
activity.
Incorporating
metal
catalyst
into
the
framework
of
photocatalyst
could
endow
unique
metallaphotoredox
platforms.
Herein,
we
assemble
carbon
nitride
nickel
(C3N4–Ni)
via
direct
coordination
Ni2+
C3N4
nitrogen,
visible-light-driven
carbon–oxygen
cross-coupling.
By
operating
with
an
imidazole
auxiliary
ligand,
C3N4–Ni
efficiently
catalyzed
etherification
variety
aryl
bromides
alcohols
or
hydroxylation
water,
exhibiting
turnover
numbers
>500.
Ni
maintained
as
isolated
single
site
without
aggregation
after
photoreaction
recovered
demonstrate
sustained
activity
additional
loading.
Our
work
signifies
potential
uniting
in
well-designed
sensitizer–metal
architecture
complex
organic
transformations.
Journal of the American Chemical Society,
Год журнала:
2021,
Номер
143(25), С. 9332 - 9337
Опубликована: Июнь 15, 2021
Here
we
report
the
use
of
pulse
radiolysis
and
spectroelectrochemistry
to
generate
low-valent
nickel
intermediates
relevant
synthetically
important
Ni-catalyzed
cross-coupling
reactions
interrogate
their
reactivities
toward
comproportionation
oxidative
addition
processes.
Pulse
provided
a
direct
means
singly
reduced
[(dtbbpy)NiBr],
enabling
identification
rapid
Ni(0)/Ni(II)
process
taking
place
under
electrolysis
conditions.
This
approach
also
permitted
measurement
Ni(I)
rates
with
electronically
differentiated
aryl
iodide
electrophiles
(kOA
=
1.3
×
104–2.4
105
M–1
s–1),
an
elementary
organometallic
step
often
proposed
in
nickel-catalyzed
reactions.
Together,
these
results
hold
implications
for
number