Abstract
In
this
study,
we
developed
a
novel
electrochemical
protocol
that
enables
the
functionalization
of
inherently
inert
C(sp
3
)−H
bonds.
protocol,
one‐electron
oxidation
acetic
acid
was
used
to
successfully
generate
methyl
radical,
which
cleaves
benzylic
bonds
substrates
via
hydrogen
atom
transfer
(HAT)
process,
and
further
reaction
with
formed
species
yields
targeted
functionalized
products.
To
best
our
knowledge,
is
first
example
use
in
HAT
process.
Notably
has
environment‐friendly
fine
economy
nature:
driven
by
conditions
absence
expensive
or
hazardous
reagents,
producing
only
gaseous
small
molecules,
hydrogen,
carbon
dioxide,
methane,
as
side
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(4), С. 2748 - 2756
Опубликована: Янв. 12, 2024
Controlling
the
enantioselectivity
of
hydrogen
atom
transfer
(HAT)
reactions
has
been
a
long-standing
synthetic
challenge.
While
recent
advances
on
photoenzymatic
catalysis
have
demonstrated
great
potential
non-natural
photoenzymes,
all
transformations
are
initiated
by
single-electron
reduction
substrate,
with
only
one
notable
exception.
Herein,
we
report
an
oxidation-initiated
enantioselective
hydrosulfonylation
olefins
using
novel
mutant
gluconobacter
ene-reductase
(GluER-W100F-W342F).
Compared
to
known
systems,
our
approach
does
not
rely
formation
electron
donor–acceptor
complex
between
substrates
and
enzyme
cofactor
simplifies
reaction
system
obviating
addition
regeneration
mixture.
More
importantly,
GluER
variant
exhibits
high
reactivity
broad
substrate
scope.
Mechanistic
studies
support
proposed
mechanism
reveal
that
tyrosine-mediated
HAT
process
is
involved.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 6, 2025
The
integration
of
ligand-to-metal
charge
transfer
(LMCT)
catalytic
paradigms
with
radical
intermediates
has
transformed
the
selective
functionalization
inert
C-H
bonds,
facilitating
use
nonprecious
metal
catalysts
in
demanding
transformations.
Notably,
aerobic
carbonylation
methane
to
acetic
acid
remains
formidable
due
rapid
oxidation
methyl
radicals,
producing
undesired
C1
oxygenates.
We
present
an
iron
terpyridine
catalyst
utilizing
LMCT
achieve
exceptional
C2/C1
selectivity
through
synergistic
photoexcitation,
generation,
and
carbonylation.
Mechanistic
studies
highlight
critical
roles
Fe(II)
Fe-carbonyl
complexes
bypassing
via
a
rebound-like
pathway,
unlocking
unprecedented
efficiency
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
Organic Chemistry Frontiers,
Год журнала:
2024,
Номер
11(18), С. 5278 - 5305
Опубликована: Янв. 1, 2024
This
review
summarizes
the
latest
methodological
advances
in
photocatalytic
C(sp
3
)–H
functionalization,
with
a
particular
emphasis
on
formation
of
C–P,
C–B,
C–S
bonds,
etc
.,
and
some
prominent
efforts
asymmetric
C–H
functionalization.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(19), С. 13347 - 13355
Опубликована: Май 6, 2024
Azide
compounds
are
widely
present
in
natural
products
and
drug
molecules,
their
easy-to-transform
characteristics
make
them
used
the
field
of
organic
synthesis.
The
merging
transition-metal
catalysis
with
radical
chemistry
offers
a
versatile
platform
for
carboazidation
alkenes,
allowing
rapid
assembly
highly
functionalized
azides.
However,
direct
use
readily
available
hydrocarbon
feedstocks
as
sp
Accounts of Chemical Research,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 18, 2024
ConspectusChemists
have
long
pursued
harnessing
light
energy
and
photoexcitation
processes
for
synthetic
transformations.
Ligand-to-metal
charge
transfer
(LMCT)
in
high-valent
metal
complexes
often
triggers
bond
homolysis,
generating
oxidized
ligand-centered
radicals
reduced
centers.
While
photoinduced
oxidative
activations
can
be
enabled,
this
process,
typically
seen
as
photochemical
decomposition,
remains
underexplored
catalytic
applications.
To
mitigate
decomposition
during
LMCT
excitation,
we
developed
a
cycle
integrating
situ
coordination,
LMCT,
ligand
homolysis
to
activate
ligated
alcohols
transiently
into
alkoxy
radicals.
This
approach
leverages
Ce(IV)
excitation
highly
reactive
radical
intermediates
selective
functionalizations
of
C(sp
Nature Synthesis,
Год журнала:
2024,
Номер
3(5), С. 568 - 575
Опубликована: Май 2, 2024
Photoinduced
C(sp3)–H
functionalization
through
hydrogen
atom
transfer
(HAT)
processes
is
pivotal
in
organic
synthesis
because
of
the
mild
reaction
conditions
and
applicability
to
late-stage
complex
molecules,
such
as
pharmaceuticals
agrochemicals.
Despite
promise,
achieving
precise
site-selectivity
overcoming
high
bond
dissociation
energy
(BDE)
unactivated
aliphatic
C–H
bonds
photoinduced
reactions,
HAT,
are
challenging.
In
this
landscape,
pyridine
N-oxides
have
emerged
potent
HAT
reagents
due
their
easily
tunable
nature.
This
Perspective
highlights
studies
showcasing
potential
site-selective
abstraction
from
explores
structure–activity
relationship
with
multiple
hydrocarbon
substrates.
Pyridine
become
promising
environmentally
friendly
owing
cost-effectiveness,
tunability
(heterogeneous)
catalysis.
Ongoing
research
on
use
will
probably
offer
additional
avenues
for
efficient
selective
functionalization.
processes,
a
useful
tool
synthesis,
but
challenges
remain.
showcases
highlighting
how
they
can
be
readily
tuned
achieve
site-selectivity.
ACS Catalysis,
Год журнала:
2025,
Номер
unknown, С. 3306 - 3313
Опубликована: Фев. 7, 2025
Herein,
we
reported
a
practical
method
to
realize
ipso-nitration
of
boronic
acids,
their
pinacol
esters,
and
trifluoroborate
salts
with
alkali
metal
salt
NaNO3
as
nitrating
reagent.
A
FeIII/FeIV
catalytic
cycle
involving
an
unusual
visible-light-induced
β-homolysis
pathway
the
N–O
bond
in
simple
iron
complex
effectively
provides
nitryl
radical
key
species.
This
protocol
bears
mild
reaction
conditions,
broad
scope
(up
99%
yield),
good
functional
group
compatibility,
convenient
scale-up
synthesis.
