Traditional
etherification
methods,
although
staples
in
synthetic
chemistry,
often
fall
short
the
efficient
construction
of
sterically
hindered
dialkyl
ethers,
especially
under
mild
and
practical
conditions.
Recent
advances
have
attempted
to
address
these
limitations,
typically
relying
on
transition
metal
catalysts,
external
reductants,
or
harsh
reaction
In
this
work,
we
disclose
a
novel
electrochemical
approach
that
enables
synthesis
ethers
from
economically
relevant
readily
accessible
alcohols
without
need
for
sacrificial
oxidants.
Our
protocol
exploits
conditions
generate
reactive
carbocations,
which
are
subsequently
captured
by
alcohol
nucleophiles
yield
desired
ethers.
This
method
is
cost-effective,
practical,
broad
scope,
providing
valuable
addition
chemists'
toolkit
ether
synthesis.
Angewandte Chemie,
Год журнала:
2024,
Номер
136(31)
Опубликована: Май 16, 2024
Abstract
Aryl
radicals
play
a
pivotal
role
as
reactive
intermediates
in
chemical
synthesis,
commonly
arising
from
aryl
halides
and
diazo
compounds.
Expanding
the
repertoire
of
sources
for
radical
generation
to
include
abundant
stable
organoboron
reagents
would
significantly
advance
chemistry
broaden
their
reactivity
profile.
While
traditional
approaches
utilize
stoichiometric
oxidants
or
photocatalysis
generate
these
reagents,
electrochemical
conditions
have
been
largely
underexplored.
Through
rigorous
mechanistic
investigations,
we
identified
fundamental
challenges
hindering
generation.
In
addition
high
oxidation
potentials
aromatic
compounds,
electrode
passivation
through
grafting,
homocoupling
radicals,
decomposition
issues
were
identified.
We
demonstrate
that
pulsed
electrosynthesis
enables
selective
efficient
by
mitigating
challenges.
Our
discoveries
facilitated
development
first
conversion
potassium
trifluoroborate
salts
into
C−P
bonds.
This
sustainable
straightforward
oxidative
approach
exhibited
broad
substrate
scope,
accommodating
various
heterocycles
chlorides,
typical
substrates
transition‐metal
catalyzed
cross‐coupling
reactions.
Furthermore,
extended
this
methodology
form
C−Se,
C−Te,
C−S
bonds,
showcasing
its
versatility
potential
bond
formation
processes.
Chemistry - A European Journal,
Год журнала:
2024,
Номер
30(48)
Опубликована: Июнь 26, 2024
We
disclose
herein
a
novel
and
general
radical
approach
to
alkylthiopurines,
encompassing
4
types
of
thiopurines,
as
well
their
corresponding
ribosides.
This
strategy
is
achieved
through
visible
light-mediated
late-stage
functionalization
the
sulfur
atoms
mercaptopurines.
The
in
situ-generated
disulfide
was
proposed
pivotal
neutral
intermediate
for
this
transformation.
present
photo-mediated
homolytic
C-S
bond
formation
preparation
alkylthiopurines
alkylthiopurine
nucleosides.
Despite
presence
reactive
sites
Minisci
reaction,
chemoselective
S-alkylation
remained
predominant
pathway.
method
allows
introduction
broad
spectrum
alkyl
groups
onto
atom
unprotective
mercaptopurine
derivatives,
2-,
6-,
8-mercaptopurine
rings.
Organoborons
serve
efficient
eco-friendly
alkylating
reagents,
providing
advantages
terms
readily
availability,
stability,
reduced
toxicity.
Further
derivatization
thioetherified
nucleosides,
together
with
anti-tumor
assays,
led
discovery
potent
agents
an
IC
Angewandte Chemie,
Год журнала:
2024,
Номер
136(44)
Опубликована: Июль 30, 2024
Abstract
This
Minireview
examines
a
selection
of
case
studies
that
showcase
distinctive
and
enabling
electrochemical
approaches
have
allowed
for
the
generation
reaction
carbocation
intermediates
under
mild
conditions.
Particular
emphasis
is
placed
on
progress
has
been
made
in
this
area
organic
synthesis
polymer
chemistry
over
past
decade.
ACS Catalysis,
Год журнала:
2024,
Номер
14(21), С. 15858 - 15868
Опубликована: Окт. 11, 2024
The
catalytic
hydrofunctionalization
of
alkenes
with
nucleophiles
via
the
generation
carbocationic
intermediates
has
been
extensively
studied
as
an
efficient
strategy
for
regioselective
installation
functional
groups
on
alkene
feedstocks.
However,
since
established
methods
are
confined
to
functionalization
position
where
is
originally
located,
it
highly
desirable
develop
a
broadly
applicable
platform
that
offers
alternative
regioselectivity
otherwise
challenging
achieve
existing
protocols.
Herein,
we
report
remote
method
enabled
by
electrooxidative
palladium
hydride
catalysis.
key
success
formation
carbocation
intermediate
through
mechanistic
pathway,
which
involves
chain-walking
process
followed
anodic
oxidation
organopalladium
species.
This
allows
terminal
and
internal
broad
range
oxygen,
carbon,
nitrogen,
fluoride
nucleophiles,
including
complex
drug-like
molecules.
Traditional
etherification
methods,
although
staples
in
synthetic
chemistry,
often
fall
short
the
efficient
construction
of
sterically
hindered
dialkyl
ethers,
especially
under
mild
and
practical
conditions.
Recent
advances
have
attempted
to
address
these
limitations,
typically
relying
on
transition
metal
catalysts,
external
reductants,
or
harsh
reaction
In
this
work,
we
disclose
a
novel
electrochemical
approach
that
enables
synthesis
ethers
from
economically
relevant
readily
accessible
alcohols
without
need
for
sacrificial
oxidants.
Our
protocol
exploits
conditions
generate
reactive
carbocations,
which
are
subsequently
captured
by
alcohol
nucleophiles
yield
desired
ethers.
This
method
is
cost-effective,
practical,
broad
scope,
providing
valuable
addition
chemists'
toolkit
ether
synthesis.
