Molecules,
Journal Year:
2023,
Volume and Issue:
28(16), P. 6127 - 6127
Published: Aug. 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
ACS Catalysis,
Journal Year:
2023,
Volume and Issue:
13(4), P. 2482 - 2488
Published: Feb. 3, 2023
The
radical
anion
of
CO2
(CO2•–)
is
a
strongly
nucleophilic
species
with
rapidly
emerging
applications
in
contemporary
organic
chemistry.
This
exhibits
high
reactivity
single-electron
reduction
reactions
due
to
the
concomitant
release
stable
CO2,
or
Giese-type
reactions,
especially
for
electron-deficient
alkenes
and
styrene
derivatives.
In
contrast
previous
reports,
we
herein
disclose
development
robust
method
introduction
CO2•–,
which
can
be
generated
from
cesium
formate
under
photoredox/hydrogen
atom
transfer
(HAT)
catalysis,
into
heteroaromatics
such
as
benzofuran,
benzothiophene,
indole
derivatives
afford
synthetically
useful
α-oxy,
α-thio,
α-amino
acid
moderate
yield.
addition,
when
using
naphthalene
derivatives,
both
addition
occur
simultaneously
produce
carboxylated
tetrahydronaphthalene
good
Moreover,
one
tetrahydronaphthalenes
that
bear
cyano
group
was
transformed
corresponding
γ-butyrolactam
via
functionality
through
hydrogenation
followed
by
cyclization.
To
best
our
knowledge,
these
dearomative
carboxylation
metal
formates
photoredox/HAT
conditions
are
unprecedented,
thus
providing
synthetic
option
C1
source
(hetero)aromatics.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 3, 2024
The
polarity
of
a
radical
intermediate
profoundly
impacts
its
reactivity
and
selectivity.
To
quantify
this
influence
predict
effects,
the
electrophilicity/nucleophilicity
>500
radicals
has
been
calculated.
This
database
open-shell
species
entails
frequently
encountered
synthetic
intermediates,
including
centered
at
sp
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(4), P. 883 - 888
Published: Jan. 22, 2024
Herein,
we
present
a
transition-metal-free,
easy
handling
protocol
for
regioselective
carboxylation
of
gem-difluorostyrenes
with
sodium
formate
as
the
C1
source.
30
examples
α-fluoracrylates
were
obtained
in
yields
to
80%
under
these
conditions.
A
defluorinative
monofluorovinyl
intermediate
and
consecutive
photoinduced
electron
transfer
mechanism
proposed
after
investigation.
ACS Catalysis,
Journal Year:
2021,
Volume and Issue:
11(24), P. 15004 - 15012
Published: Dec. 1, 2021
A
photoredox
activation
mode
of
formate
salts
for
carboxylation
was
developed.
Using
a
salt
as
the
reductant,
carbonyl
source,
and
hydrogen
atom
transfer
reagent,
wide
range
alkenes
can
be
converted
into
acid
products
via
carboxyl
group
strategy
in
an
additive-free
fashion.
Mechanistic
studies
revealed
that
radical
anion
species
(CO2•–
carbon
anions
derived
from
reduction
alkenes)
are
key
intermediates
transformation.
This
method
has
advantages
high
catalytic
efficiency
simple
system,
which
may
allow
this
approach
to
become
promising
industrial
applications.
Organic Letters,
Journal Year:
2022,
Volume and Issue:
24(22), P. 4075 - 4080
Published: June 1, 2022
We
describe
a
catalytic
strategy
for
direct
single
C(sp3)-F
bond
alkylation
of
trifluoromethylbenzimidazoles
under
photoinduced
thiol
catalysis
process.
The
CO2
radical
anion
(CO2•-)
proved
to
be
the
most
efficient
single-electron
reductant
realize
such
transformation.
spin-center
shift
generated
intermediate
is
key
step
in
realizing
C-F
activation
mild
conditions
with
high
efficiency.
National Science Open,
Journal Year:
2022,
Volume and Issue:
2(2), P. 20220024 - 20220024
Published: June 14, 2022
Dicarboxylic
acids,
which
are
appealing
structural
motifs
in
organic
synthesis
and
exist
widely
bioactive
compounds,
have
been
used
as
important
monomers
the
polymer
industry
to
construct
valuable
materials.
The
dicarboxylation
with
CO2
provides
a
convenient
potent
way
furnish
value-added
dicarboxylic
acids
via
chemical
fixation
of
two
molecules.
Beyond
any
doubt,
development
dicarboxylation,
especially
bulk
chemicals,
might
represent
promising
prospect
capture
utilization
(CCU).
In
this
review,
we
critically
summarized
comprehensively
reviewed
advances
made
past
decades
under
electro-,
photo-
transition
metal-mediated/catalytic
systems.
Moreover,
advantages
limitations
such
reactions
pointed
out
unravel
further
for
future
scientific
industrial
synthesize
high
selectivity
efficiency.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(38)
Published: July 21, 2022
Abstract
Highly
selective
and
direct
electroreductive
ring‐opening
carboxylation
of
epoxides
with
CO
2
in
an
undivided
cell
is
reported.
This
reaction
shows
broad
substrate
scopes
within
styrene
oxides
under
mild
conditions,
providing
practical
scalable
access
to
important
synthetic
intermediate
β
‐hydroxy
acids.
Mechanistic
studies
show
that
functions
not
only
as
a
carboxylative
reagent
this
but
also
promoter
enable
efficient
chemoselective
transformation
additive‐free
electrochemical
conditions.
Cathodically
generated
α
‐radical
‐carbanion
intermediates
lead
the
regioselective
formation
‐carboxylation
products.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(18)
Published: Feb. 25, 2023
Herein,
we
describe
a
practical
protocol
for
the
removal
of
alcohol
functional
groups
through
reductive
cleavage
their
benzoate
ester
analogs.
This
transformation
requires
strong
single
electron
transfer
(SET)
reductant
and
means
to
accelerate
slow
fragmentation
following
substrate
reduction.
To
accomplish
this,
developed
photocatalytic
system
that
generates
potent
from
formate
salts
alongside
Brønsted
or
Lewis
acids
promote
reduced
intermediate.
deoxygenation
procedure
is
effective
across
structurally
electronically
diverse
alcohols
enables
variety
difficult
net
transformations.
no
precautions
exclude
air
moisture
remains
efficient
on
multigram
scale.
Finally,
can
be
adapted
one-pot
benzoylation-deoxygenation
sequence
enable
direct
deletion.
Mechanistic
studies
validate
role
acidic
additives
key
C(sp
