Formal Dehydrative [3+2] Annulation of N‐Arylhydroxamine and Activated Alkyne Toward Indole
Asian Journal of Organic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 20, 2025
Abstract
An
efficient
approach
for
the
synthesis
of
indole
by
annulation
N
‐substituted
hydroxylamine
with
activated
alkynes
under
mild
reaction
conditions
was
established
without
additional
catalyst
or
chemical
reagents.
Both
3‐substituted
and
2,3‐disubstituted
indoles
were
obtained
good‐to‐excellent
isolated
yields
using
terminal
internal
electron‐deficient
alkynes,
respectively.
This
novel
green
protocol
provides
a
rapid,
mild,
method
construction
heterocycles.
Язык: Английский
Iron-Catalyzed [3 + 2] Annulation of O-Acyl Oximes with 2-Hydroxy-1-Naphthoates for the Synthesis of Benzo[g]indoles
Organic Letters,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 28, 2025
An
iron-catalyzed
[3
+
2]
annulation
of
O-acyl
oximes
with
2-hydroxy-1-naphthoates
has
been
developed.
This
strategy
features
the
simultaneous
activation
both
substrates
to
form
two
radical
intermediates.
Subsequent
selective
C-N
coupling
followed
by
sequential
condensation
and
1,3-ester
migration
affords
1H-
or
3H-benzo[g]indoles.
In
terms
derived
from
4-oxocyclohexanone
4-azacyclohexanone,
further
ring-opening
furnishes
2-(2-hydroxyethyl)-
2-(2-aminoethyl)-1H-benzo[g]indoles.
Язык: Английский
Cascade Alkynyl Prins Cyclization and Aza-Michael Reaction: En Route to Regioselective Pyrano- and Isochromenoquinoline Scaffolds
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 20, 2024
A
metal-free,
Lewis
acid
approach
for
the
regioselective
synthesis
of
dihydropyranoquinoline
scaffolds
has
been
unveiled.
The
methodology
employs
a
cascade
alkynyl
Prins-aza-Michael
reaction
sequence
to
deliver
products
in
good
excellent
yields.
strategy
features
mild
conditions,
broad
substrate
scope,
and
high
functional
group
tolerance.
protocol
further
extended
include
isochromenoquinoline
derivatives.
utility
lies
highly
fused
polycyclic
N,O-heterocycles
via
intramolecular
Heck
coupling.
Additionally,
Rh(III)-catalyzed
annulation
results
formation
fluorescent
pentacyclic
ammonium
salts
Photophysical
studies
reveal
that
these
exhibit
strong
emission
green
region
(500-550
nm).
Язык: Английский