Organic & Biomolecular Chemistry,
Journal Year:
2023,
Volume and Issue:
21(46), P. 9275 - 9285
Published: Jan. 1, 2023
Molecular-iodine
catalyzed
access
to
an
important
class
of
bio-relevant
indole
derivatives,
cyclopenta[b]indoles,
has
been
achieved
via
a
cascade
addition/intramolecular
cyclization
reaction
indoles
and
acetone.
Explorations
diverse
substitution
patterns
revealed
essential
substrate-control
in
the
reaction.
The
high-density
electronic
core
is
pivotal
favouring
formation
indolyl-cyclopenta[b]indole
derivatives;
contrast,
electron
deficiency
hindered
process,
directing
bis(indolyl)propanes.
Investigations
on
mechanistic
pathway
that
bis(indolyl)alkanes
were
intermediates
for
addition-cyclization
process.
This
simple
experimental
method
provides
sustainable
synthetic
cyclopentannulated
indoles.
Beilstein Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
20, P. 1436 - 1443
Published: June 28, 2024
An
efficient
protocol
for
the
synthesis
of
polyfunctionalized
tetrahydrocyclopenta[4,5]pyrrolo[2,3-
b
]pyridine-3,4b,5,6,7(1
H
)-pentacarboxylates
was
developed
by
a
three-component
reaction.
In
absence
any
catalyst,
reaction
alkyl
isocyanides,
dialkyl
but-2-ynedioates
and
5,6-unsubstituted
1,4-dihydropyridines
in
refluxing
acetonitrile
afforded
high
yields
with
diastereoselectivity.
The
finished
situ
generation
activated
5-(alkylimino)cyclopenta-1,3-dienes
from
addition
isocyanide
to
two
molecules
sequential
formal
[3
+
2]
cycloaddition
1,4-dihydropyridine.
The Journal of Organic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 14, 2025
Here,
we
revealed
a
convenient
synthetic
protocol
for
unique
pyrido[2,3-c]pyridazine
and
pyrido[3,2-e][1,2]oxazine
scaffolds
with
excellent
regioselectvity
diastereoselectivity.
The
functionalized
pyrido[2,3-c]
pyridazines
were
successfully
synthesized
via
Cs2CO3-promoted
[4
+
2]
cycloaddition
reaction
of
α-halogenated
N-tosylhydrazones
or
N-acylhydrazones
5,6-unsubstituted
1,4-dihydropyridines
under
mild
conditions.
Additionally,
the
similar
base-promoted
α-chlorogenated
oximes
afforded
pyrido[3,2-e][1,2]oxazines
in
satisfactory
yields.
features
this
included
conditions,
broad
substrate
scopes,
high
functional
group
tolerance,
significant
atomic
economy.
The Journal of Organic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 16, 2025
An
approach
to
cyclohepta[b]indoles
via
the
formal
(4
+
3)
annulation
of
readily
synthesized
2-indolyl-derived
1,3-dicarbonyl
compounds
acrolein
and
enones
was
developed.
The
process
is
initiated
by
catalytic
Michael
addition,
wherein
adduct
generated
in
situ.
subsequent
addition
a
Bro̷nsted
acid
catalyst
triggers
cascade
that
includes
intramolecular
Friedel–Crafts
hydroxylalkylation
followed
dehydration.
reaction
relatively
undemanding
since
even
degrading
chloroform
able
initiate
it.
obtained
tetrahydrocyclohepta[b]indoles
were
prone
toward
easy
dimerization,
underscoring
high
reactivity
double
bond
seven-membered
ring.
ChemistrySelect,
Journal Year:
2023,
Volume and Issue:
8(37)
Published: Oct. 2, 2023
Abstract
A
convenient
synthetic
protocol
for
the
construction
of
spiro[indoline‐3,3′‐quinoline]‐2,5′‐dione
motifs
was
successfully
developed
by
base
promoted
one‐pot
three‐component
reaction.
In
presence
piperidine,
reaction
ammonium
acetate,
aromatic
aldehydes
and
in
situ
generated
3‐isatyl
1,4‐dicarbonyl
compounds,
which
were
derived
from
mediated
addition
dimedone
to
3‐methyleneoxindoles,
resulted
two
diastereoisomers
derivatives
good
yields
with
diastereoselectivity.
The
stereochemistry
clearly
elucidated
isolation
diastereomers
determination
several
single
crystal
structures.
Molecules,
Journal Year:
2024,
Volume and Issue:
29(6), P. 1251 - 1251
Published: March 12, 2024
Herein,
a
Sc(OTf)3-catalyzed
(3+2)
annulation
of
2-indolylmethanols
with
propargylic
alcohols
is
reported.
The
reaction
proceeds
via
Friedel–Crafts-type
allenylation/5-exo-annulation
cascade.
In
the
reaction,
2-indolylmethanol
used
as
three-carbon
synthon,
and
propargyl
alcohol
two-carbon
synthon.
This
method
provides
direct
high-yield
pathway
for
synthetically
useful
cyclopenta[b]indoles.
general,
features
easily
accessible
substrates
broad
scope
generality,
formation
multiple
bonds
high
efficiency,
easy
scale-up.
Chemistry - A European Journal,
Journal Year:
2024,
Volume and Issue:
30(34)
Published: April 16, 2024
Cyclohepta[b]indoles,
prevalent
in
natural
products
and
pharmaceuticals,
are
conventionally
accessed
via
metal
or
Lewis
acid-mediated
cycloadditions
with
prefunctionalized
substrates.
Our
study
introduces
an
innovative
sequential
catalytic
assembly
for
synthesizing
cyclohepta[b]indoles
from
readily
available
isatin
derivatives.
The
process
involves
three
sequences:
ring-closing
metathesis,
hydrogenation,
acid-catalyzed
ring
expansion.
RCM
of
2,2-dialkene-3-oxindoles,
formed
by
butenyl
Grignard
addition
to
3-allyl-3-hydroxy-2-oxindoles,
yields
versatile
spirocyclohexene-3-oxindole
These
derivatives
undergo
further
transformations,
including
dibromination,
dihydroxylation,
epoxidation,
Wacker
oxidation
at
the
double
bond.
Hydrogenation
spirocyclohexane-3-oxindoles.
Their
subsequent
expansion/aromatization,
dependent
on
acid
catalyst,
results
either
cyclohepta[b]indole-indoline
conjugates,
adding
a
unique
synthetic
dimension.
utility
this
methodology
is
exemplified
through
synthesis
A-FABP
inhibitor,
showcasing
its
potential
pharmaceutical
applications.
