The Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
89(15), P. 11078 - 11082
Published: July 17, 2024
This
study
describes
the
synthesis
of
4-azafluorenone
core
in
a
single
operation
using
readily
available
starting
materials.
Condensation
an
amidrazone
with
ninhydrin
intercepts
intermediate
1,2,4-triazine
derivative,
which
engages
norbornadiene
merged
[4
+
2]/bis-retro[4
2]
sequence
to
deliver
azafluorenone
core.
The
tricyclic
established
this
manner
was
elaborated
onychine,
simplest
natural
product
alkaloid
family.
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.
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
144(11), P. 4810 - 4818
Published: March 8, 2022
Achieving
C3-selective
pyridine
functionalization
is
a
longstanding
challenge
in
organic
chemistry.
The
existing
methods,
including
electrophilic
aromatic
substitution
and
C–H
activation,
often
require
harsh
reaction
conditions
excess
generate
multiple
regioisomers.
Herein,
we
report
method
for
borane-catalyzed
tandem
reactions
that
result
exclusively
alkylation
of
pyridines.
These
consist
hydroboration,
nucleophilic
addition
the
resulting
dihydropyridine
to
an
imine,
aldehyde,
or
ketone,
subsequent
oxidative
aromatization.
Because
limiting
reactant
are
mild,
this
constitutes
practical
tool
late-stage
structurally
complex
pharmaceuticals
bearing
moiety.
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.
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
144(32), P. 14463 - 14470
Published: Aug. 1, 2022
Herein,
we
report
a
method
for
C3-selective
C–H
tri-
and
difluoromethylthiolation
of
pyridines.
The
relies
on
borane-catalyzed
pyridine
hydroboration
generation
nucleophilic
dihydropyridines;
these
intermediates
react
with
trifluoromethylthio
difluoromethylthio
electrophiles
to
form
functionalized
dihydropyridines,
which
then
undergo
oxidative
aromatization.
can
be
used
late-stage
functionalization
drugs
the
new
drug
candidates.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(9), P. 4994 - 5000
Published: Feb. 24, 2023
Chiral
organosilanes
do
not
exist
in
nature
and
are
therefore
absent
from
the
"chiral
pool".
As
a
consequence,
synthetic
approaches
toward
enantiopure
silanes,
stereogenic
at
silicon,
rather
limited.
While
catalytic
asymmetric
desymmetrization
reactions
of
symmetric
organosilicon
compounds
have
been
developed,
utilization
racemic
silanes
dynamic
kinetic
transformation
(DYKAT)
or
resolution
(DKR)
would
significantly
expand
breadth
accessible
Si-stereogenic
compounds.
We
now
report
DYKAT
allyl
enabled
by
strong
confined
imidodiphosphorimidate
(IDPi)
catalysts,
providing
access
to
silyl
ethers.
The
products
this
reaction
easily
converted
into
useful
monohydrosilanes.
propose
spectroscopically
experimentally
supported
mechanism
involving
epimerization
catalyst-bound
intermediate.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
62(6)
Published: Dec. 15, 2022
Methods
for
C-H
cyanation
of
pyridines
are
rare.
Here,
we
report
a
method
C3-selective
by
tandem
process
with
the
reaction
an
in
situ
generated
dihydropyridine
cyano
electrophile
as
key
step.
The
is
suitable
late-stage
functionalization
pyridine
drugs.
low
reduction
potential
and
effective
transfer
nitrile
group
were
found
to
be
essential
success
this
method.
We
studied
mechanism
detail
means
control
experiments
theoretical
calculations
that
combination
electronic
steric
factors
determined
regioselectivity
reactions
involving
C2-substituted
pyridines.
Chemical Science,
Journal Year:
2024,
Volume and Issue:
15(31), P. 12442 - 12450
Published: Jan. 1, 2024
A
practical
and
general
C-4
functionalization
strategy
of
unbiased
pyridines
is
developed
by
identifying
a
readily
synthesized
substituted
urea
as
the
pyridine
activation
reagent.
Journal of the American Chemical Society,
Journal Year:
2021,
Volume and Issue:
144(2), P. 679 - 684
Published: Dec. 30, 2021
Tacticity
is
a
crucial
factor
affecting
the
properties
of
synthetic
polymer
materials.
Here,
we
introduce
type
chiral
organic
Brønsted
acid
catalyst,
1,1'-bi-2-naphthol-derived
N,N'-bis(triflyl)phosphoramidimidates
(PADIs),
for
cationic
polymerization
vinyl
ethers,
which
enables
development
first
organocatalytic,
highly
stereoselective,
reversible
addition-fragmentation
chain-transfer
(RAFT)
ethers
with
trithiocarbonate
agent.
This
metal-free
RAFT
process
could
afford
isotactic
poly(vinyl
ethers)
high
stereoselectivity,
controllable
molecular
mass,
and
narrow
dispersity
at
low
catalyst
loadings
(as
as
200
ppm).
Moreover,
chain-end
allows
chain
extension
to
synthesize
diblock
copolymers
comprising
an
ether)
block,
by
mechanistic
switching
from
stereoselective
visible-light-regulated
radical
polymerization.
