Regioselective Aryne Annulations of N-Tosyl-2-enamides and N-tert-Butylsulfinyl-2-enamides for the Construction of Dihydroquinolin-4-one and Chroman-4-imine Units
Organic Letters,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 14, 2025
A
regioselective
synthesis
of
the
dihydroquinolin-4-one
4
is
achieved
from
aryne-mediated
annulation
an
o-(trimethylsilyl)aryl
triflate
1
with
N-tosyl-2-enamide
2
in
presence
TBAT
toluene,
whereas
chroman-4-imine
5
formed
reaction
N-(tert-butylsulfinyl)-2-enamide
3
and
TBAF
THF.
Governing
factors
for
regioselectivity
have
been
accounted
as
strong
steric
electronic
effects
between
N-toluenesulfonyl
N-tert-butylsulfinyl
groups
3.
The
methods
described
herein
are
successful
various
substrates
or
high
levels
regioselectivity,
diastereoselectivity
5.
Язык: Английский
C-to-N atom swapping and skeletal editing in indoles and benzofurans
Nature,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 21, 2025
Abstract
Skeletal
editing
comprises
the
structural
reorganization
of
compounds.
Such
can
be
achieved
through
atom
swapping,
insertion,
deletion
or
compound’s
backbone
structure
1,2
.
Conducted
at
a
late
stage
in
drug
development
campaigns,
skeletal
enables
diversification
an
existing
pharmacophore,
enhancing
efficiency
development.
Instead
constructing
heteroarene
classically
from
basic
building
blocks,
variants
are
readily
accessible
directly
starting
lead
compound
approved
pharmacophore.
Here
we
present
C
to
N
swapping
indoles
C2
position
give
indazoles
oxidative
cleavage
indole
core
and
subsequent
ring
closure.
Reactions
proceed
ring-opened
oximes
as
intermediates.
These
deconstructed
intermediates
also
diverted
into
benzimidazoles
resulting
overall
with
concomitant
reorganization.
The
same
diverting
strategies
equally
well
applicable
benzofurans
leading
either
benzisoxazoles
benzoxazoles.
classes
obtained
these
methods—indazoles
3,4
,
5
6,7
benzoxazoles
8
—are
biologically
relevant
moieties
found
substructures
natural
products
pharmaceuticals.
procedures
introduced
substantially
enlarge
methods
portfolio
emerging
field
editing.
Язык: Английский
Synthesis of Polyfunctional Indazoles via Novel Rearrangement of Isatin Derivatives
Asian Journal of Organic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 3, 2025
Abstract
In
this
work
we
present
a
new
method
for
indazole
synthesis
through
the
unexpected
rearrangement
of
various
7‐nitroisatins
during
reaction
with
hydrazine
hydrate.
The
pyrazole
cycle
is
formed
via
direct
metal‐free
C−H
amination.
We
demonstrate
limitations
discovered
approach
and
several
accessible
methods
functionalization
compounds
to
obtain
novel
derivatives.
Язык: Английский
Cobalt‐Promoted Para C─H Amination of 3‐Acetyl Substituted Nitroarenes with Arylhydrazines
ChemistrySelect,
Год журнала:
2024,
Номер
9(43)
Опубликована: Ноя. 1, 2024
Abstract
We
report
a
method
to
furnish
substituted
1H
‐indazoles
via
coupling
of
3‐acetyl
nitroarenes
and
arylhydrazines.
Reactions
progressed
in
the
presence
cobalt(II)
acetylacetonate
catalyst,
TEMPO
oxidant,
Cs
2
CO
3
base.
Functional
groups
including
bromo,
chloro,
nitro,
trifluoromethoxy
were
compatible
with
reaction
conditions.
The
proposed
mechanism
was
based
on
nucleophilic
substitution
hydrogen
para
nitro
group.
Our
feature
convenient
pathway
directly
obtain
which
avoid
use
pre‐functionalized
starting
materials.
Indazole
could
play
role
as
directing
group
for
palladium‐catalyzed
C(sp
)─H
arylation
iodobenzene.
Язык: Английский
Hydroxylamine‐O‐Sulfonic Acid (HOSA): A Recent Synthetic Overview
ChemistrySelect,
Год журнала:
2024,
Номер
9(35)
Опубликована: Сен. 12, 2024
Abstract
Hydroxylamine‐
O‐
sulfonic
acid
has
been
used
as
a
versatile
nitrogen
source
in
synthetic
organic
chemistry.
It
dual
function
and
utilized
both
nucleophile
an
electrophile
during
different
transformations.
This
reagent
is
stable
easy
to
handle
aqueous
solvents.
can
be
with
functional
groups
under
mild
reaction
conditions,
making
its
widely
applicable
for
constructing
complex
molecules.
various
applications
such
agrochemicals,
pharmaceuticals,
polymer
industries
the
formation
of
S−N,
C−N,
O−N,
N−N
bonds,
well
efficient
cyclization
reactions
metal‐free
conditions
excellent
stereo–
regioselectivity.
The
present
review
provides
brief
overview
all
advancements
made
past
two
decades
using
hydroxylamine‐
source.
Язык: Английский
Palladium‐Catalyzed 2‐Aminoacetophenone Oxime Directed β‐sp2 and γ‐sp3 C─H Bond Functionalization of Aryl Carboxamides
ChemistrySelect,
Год журнала:
2024,
Номер
9(45)
Опубликована: Ноя. 26, 2024
Abstract
Pd(II)‐catalyzed
2‐aminoacetophenone
oxime‐assisted
sp
2
and
3
C─H
arylation
of
aryl
carboxamides
is
disclosed.
The
oxime
an
N,N
‐bidentate
auxiliary
that
proceeds
activation
through
a
six‐membered
palladacycle
intermediate,
the
activation/functionalization
on
C(sp
)─H
bond
by
ligand
novel
achieved.
This
facilitates
subsequent
in
one
step.
optimized
protocol
enables
access
to
various
groups
at
β
‐sp
‐
γ
‐centers
carboxamides.
bidentate
easy
synthesize
gram
scale,
we
also
described
deoximination
procedure
after
functionalization.
Язык: Английский