Molecules,
Год журнала:
2023,
Номер
28(16), С. 6127 - 6127
Опубликована: Авг. 18, 2023
The
functionalisation
of
C–H
bonds
has
been
an
enormous
achievement
in
synthetic
methodology,
enabling
new
retrosynthetic
disconnections
and
affording
simple
equivalents
for
synthons.
Hydrogen
atom
transfer
(HAT)
is
a
key
method
forming
alkyl
radicals
from
substrates.
Classic
reactions,
including
the
Barton
nitrite
ester
reaction
Hofmann–Löffler–Freytag
reaction,
among
others,
provided
early
examples
HAT.
However,
recent
developments
photoredox
catalysis
electrochemistry
have
made
HAT
powerful
tool
capable
introducing
wide
range
functional
groups
into
bonds.
Moreover,
greater
mechanistic
insights
stimulated
development
increasingly
site-selective
protocols.
Site-selectivity
can
be
achieved
through
tuning
electron
density
at
certain
using
additives,
judicious
choice
reagent,
solvent
system.
Herein,
we
describe
latest
methods
functionalizing
C–H/Si–H/Ge–H
indirect
between
2018–2023,
as
well
critical
discussion
reagents,
aspects,
substrate
scopes,
background
contexts
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(40), С. 27583 - 27593
Опубликована: Сен. 26, 2024
The
exploration
of
strong
chemical
bonds
as
synthetic
handles
offers
new
disconnection
strategies
for
the
synthesis
functionalized
molecules
via
transition
metal
catalysis.
However,
slow
oxidative
addition
rate
these
covalent
to
a
center
hampers
their
utility.
Here,
we
report
C(sp
Organic Letters,
Год журнала:
2023,
Номер
25(22), С. 4056 - 4060
Опубликована: Май 31, 2023
A
Giese
reaction
of
aryl
bromides
with
electron-deficient
alkenes
was
developed,
enabled
by
a
dual
catalyst
system
containing
NiII
complex
and
IrIII
photocatalyst.
This
protocol
could
accommodate
variety
alkenes,
delivering
the
conjugate
adducts
in
up
to
97%
yield.
The
utilization
photoexcited
(dtbbpy)NiII(aryl)Br
intermediate
as
an
radical
source
allows
this
novel
transformation
halides,
thus
expanding
chemical
space
excited
nickel
catalysis.
Green Chemistry,
Год журнала:
2023,
Номер
25(21), С. 8820 - 8825
Опубликована: Янв. 1, 2023
An
efficient
and
mild
multicomponent
reaction
(MCR)
for
the
preparation
of
vinyl
sulfones
achieved
by
carrying
out
hydrosulfonylation
alkynes
with
corresponding
aryl
diazonium
salts,
K
2
S
O
5
thiophenols
at
room
temperature
without
any
metal
catalysts
or
additives.
Synthesis,
Год журнала:
2023,
Номер
56(13), С. 1967 - 1978
Опубликована: Ноя. 21, 2023
Abstract
The
absorption
of
light
by
photosensitizers
has
been
shown
to
offer
novel
reactive
pathways
through
electronic
excited
state
intermediates,
complementing
ground-state
mechanisms.
Such
strategies
have
applied
in
both
photocatalysis
and
photoredox
catalysis,
driven
generating
intermediates
from
their
long-lived
states.
One
developing
area
is
photoinduced
ligand-to-metal
charge
transfer
(LMCT)
which
coordination
a
ligand
metal
center
subsequent
excitation
with
results
the
formation
radical
reduced
center.
This
mini
review
concerns
foundations
recent
developments
on
transition-metal
focusing
organic
transformations
made
possible
this
mechanism.
1
Introduction
2
Iron
3
Cobalt
4
Nickel
5
Copper
6
Future
Outlook
Conclusion
ACS Catalysis,
Год журнала:
2024,
Номер
14(15), С. 11378 - 11388
Опубликована: Июль 16, 2024
Dual
IrIII/LnNiII
metallaphotoredox
catalyzed
C(sp3)–C(sp2)
cross-coupling
reactions
are
widely
assumed
to
proceed
by
photoinduced
single
electron
transfer
steps
due
the
highly
oxidizing
IrIII*
excited
state
(IrIII
=
[Ir(dF(CF3)ppy)2(dtbbpy)]+[PF6]−;
dF(CF3)ppy
2-(2,4-difluorophenyl)-5-(trifluoromethyl)pyridine;
Ln
dtbbpy
4,4′-di-tert-butyl-2,2′-bipyridine).
Using
time-resolved
absorption
and
emission
spectroscopy,
we
reveal
that
energy
between
various
LnNiII
precatalysts
intermediates
with
kq
≥
108
M–1
s–1
also
drives
catalysis.
Specifically,
states
of
dihalide
precatalysts/organometallic
accessible
appear
drive
bond
homolysis,
halogen
radical
elimination,
reductive
elimination
facilitate
formation
cross-coupled
products.
Energy
dynamics
consequently
circumvent
need
for
transfer,
thereby
extending
substrate
scopes
coupling
partners
cannot
be
oxidized
IrIII*.
Within
a
cross-electrophile
model
reaction
4-bromobenzotrifluoride
bromocyclohexane,
activates
precatalyst
at
early
times
before
nucleophilic
reductants
present.
In
absence
IrIII,
direct
excitation
LnNiII(Br)2
form
LnNiII(Br)(Aryl)
intermediate.
To
compare
kinetics,
determined
rate
constants
quenching
Br–
(kSET
4.1
×
s–1)
subsequent
from
reduced
IrIII•–
107
using
Stern-Volmer
analysis
pulse
radiolysis,
respectively.
competitive
is
parallel
pathway
within
Exploiting
mechanism,
demonstrate
selective
4-chlorobenzotrifluoride
bromocyclohexane
exclusively
product.
With
alkyl-trifluoroborate
nucleophiles
do
not
reductively
quench
emission,
transmetalation
LnNiII(Br/Cl)(Aryl)
followed
Similarly,
rather
than
NiII
oxidation
C(sp2)–OR
despite
strongly
ability
total,
these
processes
in
catalysis
can
unlock
alternative
reactive
pathways.
Chinese Journal of Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 17, 2025
Comprehensive
Summary
A
practical
photocatalytic
annulation‐biselenylation
strategy
has
been
developed
for
the
efficient
synthesis
of
biselenium‐substituted
1‐indanones
(38
examples
in
total)
with
generally
good
yields
(up
to
95%)
and
excellent
stereoselectivity
(>19
:
1
Z
/
E
ratio)
by
employing
enynones
diaryl
selenides
as
starting
materials
under
photosensitizer‐free
conditions.
The
reaction
mechanism
involves
a
cascade
process
comprising
homolytic
cleavage,
radical
addition,
5‐
exo
‐
dig
cyclization,
capture,
enabling
sequential
formation
multiple
bonds,
such
C(sp
3
)‐Se,
)‐C(sp
2
),
)‐Se
rapidly
construct
molecular
complexity.
Notably,
this
approach
demonstrates
wide
substrate
compatibility
tolerability
towards
various
functional
groups.
It
is
further
characterized
its
remarkable
efficiency
creating
chemical
bonds
achieving
high
atomic
utilization
100%.
Organic Letters,
Год журнала:
2023,
Номер
25(46), С. 8387 - 8392
Опубликована: Ноя. 15, 2023
By
extending
the
photoinduced
oxidative
mechanism
of
aryl
tertiary
amines
proposed
earlier
to
an
alkaline
environment
based
on
prediction
quantum
mechanics
computations
and
validation
meticulous
experiments,
we
discovered
a
N-dealkylation
method
for
both
amides.
The
dealkylation
was
achieved
in
under
mild
conditions
accompanied
by
excellent
functional
group
tolerance.
Abstract
α‐Aryl
cyclocarbonyls
are
important
building
blocks
in
organic
synthesis.
While
many
methods
have
been
developed
for
their
synthesis,
the
use
of
readily
available
and
inexpensive
aryl
chlorides
as
arylating
reagent
remains
rare.
Herein,
we
report
an
α‐arylation
cyclic
ketones
with
under
reductive
electrophotocatalytic
conditions.
2,6‐Diisopropylphenyl‐containing
naphthalenemonoimide
was
identified
optimal
electrophotocatalyst,
allowing
electron‐deficient
well
electron‐rich
mild
