Organic & Biomolecular Chemistry,
Journal Year:
2021,
Volume and Issue:
20(2), P. 352 - 357
Published: Dec. 11, 2021
An
efficient
DABCO/Cu(OAc)
2
promoted
one-pot
access
to
pharmacologically
exciting
highly
substituted
6-hydroxyaryl-2-aminonicotinonitriles
in
good
high
yields
is
reported.
Organic & Biomolecular Chemistry,
Journal Year:
2022,
Volume and Issue:
20(34), P. 6759 - 6765
Published: Jan. 1, 2022
A
remarkable
metal-oxidant-solvent-
and
base-free
domino
route
for
regioselective
access
to
a
wide
range
of
2,4-di-
2,3,4/6-trisubstituted
pyridines
including
carbo-
heterocyclic
fused
is
reported.
This
[3C
+
2C
1N]
cyclization
reaction
occurs
between
3-chloropropiophenones
(3C
units),
enolizable
acyclic/cyclic
ketones
(2C
sources)
NH4OAc
as
robust
N
source
under
neat
conditions
an
open
atmosphere,
producing
new
C=C
C=N-C
bonds
in
highly
chemo-
manners.
Interestingly,
this
eco-friendly
method
has
many
positive
features:
excellent
functional
group
tolerance,
broad
substrate
scope,
good
regioselectivities,
promising
yields,
no-unwanted
products,
neutral
appropriateness
large-scale
synthesis.
Mechanism
studies
reveal
that
the
situ
generated
β-amino
ketone
from
3-chloropropiophenone
ammonium
salt
undergoes
C=N
bond
formation
with
followed
by
intramolecular
process
(C=C
bond),
which
are
decisive
steps
pyridine
Asian Journal of Organic Chemistry,
Journal Year:
2022,
Volume and Issue:
11(12)
Published: Nov. 1, 2022
Abstract
The
β‐Csp
3
−H
functionalization
of
N‐sulfonyl
ketimines
with
2‐(2‐enynl)pyridines/quinolines
via
a
cooperative
Ag(I)‐/organobase‐catalyzed
5‐
endo‐dig
cyclization‐addition
reaction
is
reported.
This
successive
C−N/C−C
bond‐making
provides
simple
and
atom‐economical
technique
for
granting
diverse
set
1,3‐disubstituted
indolizines/pyrrolo[1,2‐
]quinolines
possessing
synthetically
resourceful
ketimine
moiety.
Moreover,
our
designed
strategy
applies
to
broad
substrates
allows
various
functionalities.
Furthermore,
this
has
many
imperative
synthetic
points
such
as
mild
conditions,
low
catalyst
loading,
acceptable
chemical
yields
highly
diastereoselective
(up
≤93
:
7
dr).
moiety
indolizine
was
easily
transmuted
into
the
reputed
classes
coumarin
benzofuran
derivatives.
Organic Chemistry Frontiers,
Journal Year:
2022,
Volume and Issue:
9(14), P. 3697 - 3708
Published: Jan. 1, 2022
A
novel
tandem
1,6-addition/cyclopropanation/rearrangement
reaction
of
vinylogous
para
-quinone
methides
with
3-chlorooxindoles
has
been
developed,
providing
dispirooxindole–cyclopentane–cyclohexadienones
vicinal
quaternary
carbon
centers.
Chemistry - An Asian Journal,
Journal Year:
2022,
Volume and Issue:
18(4)
Published: Dec. 30, 2022
A
powerful
CuCl-catalyzed
sequential
one-pot
reaction
of
aryl
methyl
ketoxime
acetates
with
cyclic
N-sulfonyl
imines
followed
by
elimination
in
the
presence
base
is
reported.
This
hydrazine-free
method
conveniently
makes
C-C
and
N-N
bonds
via
a
radical
cleavage
N-O
bond,
delivering
special
class
C3-hydroxyarylated
pyrazoles
good
yields.
Surprisingly,
while
employing
CuI
as
catalyst
instead
CuCl,
proceeds
through
non-radical
pathway
which
embodies
new
tactic
for
high-yielding
access
to
value-added
conjugated
N-unsubstituted
ketimines.
Moreover,
additive-free
approach
sulfamidate-fused-pyrazoles
was
achieved
successfully
catalyzing
addition
oxidative
bond-making
reactions
respectively.
Significantly,
our
novel
technique
could
convert
prepared
ketimines
into
pharmacologically
recognized
6H-benzo[c]chromene
frameworks.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Sept. 23, 2024
Isoquinolines
are
ubiquitous
arenes
found
in
many
biologically
useful
molecules.
While
direct
substitution
at
the
heterocyclic
ring
is
uncommon,
reductive
functionalization
to
form
tetrahydroisoquinolines
(THIQs)
straightforward.
Herein,
we
describe
a
facile
method
for
producing
C4-functionalized
isoquinolines
from
readily
available
parent
THIQ.
This
high-temperature
transformation
utilizes
pyridine-
European Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
26(33)
Published: July 11, 2023
Abstract
An
efficient
sequential
one‐pot,
two‐step
pseudo‐four‐component
reaction
between
3/4‐methyl
N
‐sulfonyl
ketimines
with
3‐chloropropiophenones
triggered
by
DIPEA/NaHCO
3
as
a
cooperative
base
and
subsequent
aza‐cyclization
using
NH
4
OAc
is
reported.
This
transition‐metal‐oxidant‐free
technique
concocts
new
C−C/C=C/C=N−C
bonds
selectively,
guaranteeing
acceptable
yields
of
2,3,6‐trisubstituted
pyridines
possessing
ortho
‐hydroxyaryl/benzenesulfonamide
propiophenone
moieties
at
C2
C3
positions,
respectively.
Interestingly,
while
replacing
methyl‐substituents
straight
alkyl
chains
ketimines,
only
monoalkylation
happened
in
situ‐generated
vinyl
ketones
to
deliver
promising
3‐picoline
derivatives.
Moreover,
the
synthetic
transmutation
prepared
pyridine
derivative
led
several
important
classes
pyridocoumarin,
5
H
‐chromenopyridine,
di(pyridin‐3‐yl)
methane
