Organic Letters,
Journal Year:
2021,
Volume and Issue:
23(17), P. 6775 - 6779
Published: Aug. 24, 2021
A
versatile
and
robust
photocatalytic
methodology
to
install
the
amide
functional
group
into
azomethine
imine
ions
is
described.
This
protocol
distinguished
by
its
broad
scope
mild
reaction
conditions,
which
are
well
suited
for
preparation
of
structurally
complex
compounds
in
form
amino
acids,
peptides,
small
drug-like
molecules.
Moreover,
generated
pyrazolidinone
core
could
be
easily
converted
β-alanine
analogues.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
60(14), P. 7873 - 7879
Published: Jan. 7, 2021
Through
the
formation
of
an
electron
donor-acceptor
(EDA)
complex,
strain-release
aminopyridylation
[1.1.1]propellane
with
N-aminopyridinium
salts
as
bifunctional
reagents
enabled
direct
installation
amino
and
pyridyl
groups
onto
bicyclo[1.1.1]pentane
(BCP)
frameworks
in
absence
external
photocatalyst.
The
robustness
this
method
to
synthesize
1,3-aminopyridylated
BCPs
under
mild
metal-free
conditions
is
highlighted
by
late-stage
modification
structurally
complex
biorelevant
molecules.
Moreover,
strategy
was
extended
P-centered
CF3
radicals
for
unprecedented
incorporation
such
functional
pyridine
across
BCP
core
a
three-component
coupling.
This
practical
lays
foundation
straightforward
construction
new
valuable
C4-pyridine-functionalized
chemical
entities,
thus
significantly
expanding
range
accessibility
BCP-type
bioisosteres
applications
drug
discovery.
Journal of the American Chemical Society,
Journal Year:
2021,
Volume and Issue:
143(7), P. 3003 - 3012
Published: Feb. 8, 2021
Site-selective
C-H
functionalization
in
chemical
feedstocks
is
a
challenging
and
useful
reaction
the
broad
field
of
research.
Here,
we
report
modular
photochemical
platform
for
site-selective
pyridylation
unactivated
hydrocarbons
via
unique
synergistic
effects
triplet
excited
anthraquinone
an
amidyl
radical-based
reverse
hydrogen
atom
transfer
(RHAT)
agent.
The
selective
tertiary
secondary
C(sp3)-H
bonds
abundant
was
achieved
by
employing
various
N-aminopyridinium
salts
highly
fashion,
thus
providing
new
catalytic
system
direct
construction
high-value-added
compounds
under
ambient
conditions.
Moreover,
this
operationally
simple
protocol
applicable
to
variety
linear-,
branched-,
cyclo-alkanes
more
complex
molecules
with
high
degrees
site
selectivity
visible-light
conditions,
which
provides
rapid
straightforward
access
versatile
synthons
upgrading
mild,
metal-free
Chemical Reviews,
Journal Year:
2023,
Volume and Issue:
123(12), P. 7655 - 7691
Published: May 3, 2023
Azines,
such
as
pyridines,
quinolines,
pyrimidines,
and
pyridazines,
are
widespread
components
of
pharmaceuticals.
Their
occurrence
derives
from
a
suite
physiochemical
properties
that
match
key
criteria
in
drug
design
is
tunable
by
varying
their
substituents.
Developments
synthetic
chemistry,
therefore,
directly
impact
these
efforts,
methods
can
install
various
groups
azine
C–H
bonds
particularly
valuable.
Furthermore,
there
growing
interest
late-stage
functionalization
(LSF)
reactions
focus
on
advanced
candidate
compounds
often
complex
structures
with
multiple
heterocycles,
functional
groups,
reactive
sites.
Because
factors
electron-deficient
nature
the
effects
Lewis
basic
N
atom,
distinct
arene
counterparts,
application
LSF
contexts
difficult.
However,
have
been
many
significant
advances
reactions,
this
review
will
describe
progress,
much
which
has
occurred
over
past
decade.
It
possible
to
categorize
radical
addition
processes,
metal-catalyzed
activation
transformations
occurring
via
dearomatized
intermediates.
Substantial
variation
reaction
within
each
category
indicates
both
rich
reactivity
heterocycles
creativity
approaches
involved.
Accounts of Chemical Research,
Journal Year:
2022,
Volume and Issue:
55(20), P. 3043 - 3056
Published: Sept. 27, 2022
ConspectusThe
radical-mediated
C–H
functionalization
of
pyridines
has
attracted
considerable
attention
as
a
powerful
tool
in
synthetic
chemistry
for
the
direct
bonds
pyridine
scaffold.
Classically,
methods
functionalized
often
involve
Minisci-type
reactions
under
strongly
acidic
conditions.
However,
site-selective
unbiased
systems
been
long-standing
challenge
because
scaffold
contains
multiple
competing
reaction
sites
(C2
vs
C4)
to
intercept
free
radicals.
Therefore,
prefunctionalization
is
required
avoid
issues
observed
with
formation
mixture
regioisomers
and
overalkylated
side
products.Recently,
N-functionalized
pyridinium
salts
have
attracting
organic
promising
radical
precursors
surrogates.
The
notable
advantage
lies
their
ability
enhance
reactivity
selectivity
synthetically
useful
acid-free
This
approach
enables
exquisite
regiocontrol
nonclassical
at
C2
C4
positions
mild
conditions,
which
are
suitable
late-stage
bioactive
molecules
greater
complexity
diversity.
Over
past
five
years,
variety
fascinating
applications
developed
using
various
types
visible
light
In
addition,
new
platform
alkene
difunctionalization
appropriately
designed
N-substituted
bifunctional
reagents
reported,
offering
an
innovative
assembly
process
complex
architectures.
Intriguingly,
strategies
involving
light-absorbing
electron
donor–acceptor
(EDA)
complexes
between
electron-rich
donors
further
open
up
photocatalyst-free
Furthermore,
we
enantioselective
afford
enantioenriched
bearing
through
single-electron
N-heterocyclic
carbene
(NHC)
catalysis.Herein,
provide
broad
overview
our
recent
contributions
development
summarize
cornerstones
that
successfully
employ
these
major
advances
field
systematically
categorized
on
basis
pyridines'
N-substituent,
N–X
(X
=
O,
N,
C,
SO2CF3),
its
patterns.
identification
activation
modes
mechanistic
aspects
discussed
by
providing
representative
each
paradigm.
We
hope
this
Account
will
inspire
interest
continued
innovation
exploration
transformations.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(29)
Published: March 24, 2023
Abstract
The
photoactivation
of
electron
donor‐acceptor
complexes
has
emerged
as
a
sustainable,
selective
and
versatile
strategy
for
the
generation
radical
species.
Electron
(EDA)
complexation,
however,
imposes
electronic
constraints
on
donor
acceptor
components
this
can
limit
range
radicals
that
be
generated
using
approach.
New
EDA
complexation
strategies
exploiting
sulfonium
salts
allow
to
from
native
functionality.
For
example,
aryl
salts,
formed
by
activation
arenes,
serve
in
due
their
electron‐deficient
nature.
This
“sulfonium
tag”
approach
relaxes
parent
substrate
dramatically
expands
complexation.
In
review,
these
new
applications
will
introduced
areas
chemical
space
rendered
accessible
through
innovation
highlighted.
Advanced Synthesis & Catalysis,
Journal Year:
2023,
Volume and Issue:
365(10), P. 1538 - 1564
Published: March 6, 2023
Abstract
Quaternary
pyridinium
compounds
are
valuable
intermediates
in
organic
synthesis,
which
have
gained
immense
popularity
the
synthetic
community.
The
application
of
transition
metal
or
photoredox
catalysis
transforming
quaternary
into
various
C−C
and
C−X
bonds
is
well
established.
A
majority
these
methods
require
high
temperatures,
expansive
catalysts,
delicate
conditions
for
successful
execution.
On
other
hand,
use
metal‐free
photocatalysis‐free
strategies
constructing
using
derivatives
has
been
sought‐after.
In
this
context,
electron‐donor‐acceptor
(EDA)‐complex
reactions
emerged
as
a
state‐of‐the‐art
methodology,
do
not
any
photocatalyst
their
EDA‐complex
photochemistry
takes
advantage
electron‐acceptor
ability
derivatives,
can
quickly
generate
radical
precursor
via
deaminative
process.
These
newly
generated
useful
several
transformations.
We
hereby,
review,
discuss
an
area
major
progress
mediated
involving
with
mechanism,
substrate
scope,
limitations.
magnified
image
Chemical Science,
Journal Year:
2024,
Volume and Issue:
15(4), P. 1204 - 1236
Published: Jan. 1, 2024
This
review
article
highlights
the
diverse
ways
in
which
recent
developments
areas
of
photocatalysis
and
visible
light
photochemistry
are
impacting
synthetic
carbohydrate
chemistry.
Journal of the American Chemical Society,
Journal Year:
2021,
Volume and Issue:
143(31), P. 11927 - 11933
Published: July 28, 2021
The
direct
position-selective
C-4
alkylation
of
pyridines
has
been
a
long-standing
challenge
in
heterocyclic
chemistry,
particularly
from
pyridine
itself.
Historically
this
addressed
using
prefunctionalized
materials
to
avoid
overalkylation
and
mixtures
regioisomers.
This
study
reports
the
invention
simple
maleate-derived
blocking
group
for
that
enables
exquisite
control
Minisci-type
decarboxylative
at
allows
inexpensive
access
these
valuable
building
blocks.
method
is
employed
on
variety
different
carboxylic
acid
alkyl
donors,
operationally
scalable,
applied
known
structures
rapid
fashion.
Finally,
work
points
an
interesting
strategic
departure
use
Minisci
chemistry
earliest
possible
stage
(native
pyridine)
rather
than
current
dogma
almost
exclusively
employs
as
late-stage
functionalization
technique.