A
novel
pyridyl-thiadiazole
ligand
has
been
designed,
synthesized,
and
employed
in
the
preparation
of
a
heterogeneous
iridium
catalyst
supported
on
multi-hydroxyl
polyhedral
oligomeric
silsesquioxane.
The
as-prepared
exhibits
excellent
catalytic
activity
one-pot
cascade
selective
synthesis
N-/C-substituted
indole
derivatives
from
amino
alcohols
via
borrowing
hydrogen
strategy.
Meanwhile,
it
was
observed
that
this
approach
good
functional
group
tolerance
broad
substrate
scope.
Notably,
by
employing
system,
an
inhibitor
against
gp41-mediated
HIV-1
fusion
core
structure
could
be
conveniently
synthesized
2-aminophenethyl
alcohol
benzyl
40.6%
total
yield
for
only
four
steps
“borrowing
hydrogen”
Mechanistic
explorations
showed
transformation
undergoes
processes,
involving
N/C-alkylation
through
strategy,
oxidative
cyclization.
Recycling
experiments
disclosed
easily
recovered
reused
at
least
seven
times
with
TON.
Chemistry - A European Journal,
Год журнала:
2024,
Номер
30(47)
Опубликована: Июнь 20, 2024
An
air-stable,
inexpensive,
and
isolable
cobalt(II)
complex
(C1)
of
N-((1-methyl-1H-imidazol-2-yl)methyl)-2-(phenylselanyl)ethan
amine
(L1)
was
synthesized
characterized.
The
used
to
catalyze
a
one-pot
cascade
reaction
between
2-(2-aminophenyl)ethanols
benzyl
alcohol
derivatives.
Interestingly,
2-aryl-3-formylindole
derivatives
were
formed
instead
N-alkylated
or
C-3
alkylated
indoles.
A
broad
substrate
scope
can
be
activated
using
this
protocol
with
only
5.0
mol
%
catalyst
loading
achieve
up
87
yield
mechanistic
studies
suggested
that
the
proceeds
through
tandem
imine
formation
followed
by
cyclization.
A
novel
Ru(II)-catalyzed
domino
reaction,
comprising
alkylation,
cyclization,
and
oxidation
of
2-aminophenethanols
with
benzyl
alcohols,
has
been
developed
for
the
synthesis
3-hydroxyindolin-2-ones.
This
transformation
exhibits
excellent
synthetic
efficiency,
enabling
selective
formation
four
or
three
σ
bonds,
one
π
bond,
quaternary
carbon
center
in
step
under
identical
conditions.
Furthermore,
it
provides
a
versatile
approach
to
3-hydroxyindolin-2-one
frameworks
distinct
substituents
at
1-
3-positions.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(24), С. 16755 - 16772
Опубликована: Ноя. 28, 2023
Herein,
we
report
a
ligand-centered
redox-controlled
oxygen-dependent
switchable
selectivity
during
ruthenium-catalyzed
selective
synthesis
of
C3-alkylated
indoles
and
bis(indolyl)methanes
(BIMs).
A
wide
variety
BIMs
were
prepared
selectively
in
moderate
to
good
isolated
yields
by
coupling
alcohols,
catalyzed
well-defined,
air-stable,
easy-to-prepare
Ru(II)-catalyst
(1a)
bearing
redox-active
tridentate
pincer
(L1a).
Catalyst
1a
efficiently
the
C3-alkylation
under
an
argon
atmosphere
while,
oxygen
environment,
exclusively
producing
BIMs.
few
drug
molecules
containing
also
synthesized
efficiently.
exhibited
excellent
chemoselectivity
with
alcohols
internal
carbon–carbon
double
bonds.
Mechanistic
investigation
revealed
that
coordinated
azo-aromatic
ligand
actively
participates
catalysis.
During
dehydrogenation
azo-moiety
stores
hydrogen
removed
from
subsequently
transfers
alkylideneindolenine
intermediate,
forming
indoles.
While
transfer
scaffold
molecular
generates
H2O2,
leaving
no
scope
for
hydrogenation
rather
than
it
undergoing
1,4-Michael-type
addition
Organic & Biomolecular Chemistry,
Год журнала:
2023,
Номер
21(43), С. 8651 - 8657
Опубликована: Янв. 1, 2023
The
transition
metal-free
Cs2CO3/Oxone®-mediated
C3-alkylation
of
indoles
proceeds
in
moderate
to
high
yields
with
a
variety
C4-C7
functionalized
and
is
applicable
2-,
3-
4-hydroxymethyl
pyridines
related
electron-deficient
heterocycles,
permitting
novel
late-stage
drug
functionalizations.
Preliminary
mechanistic
studies
support
hydrogen
autotransfer-type
chain
process
starting
an
initial
oxidation
the
alcohol
corresponding
aldehyde,
followed
by
subsequent
condensation
onto
indole
reduction/hydride
delivery
from
another
equivalent
primary
alcohol.
Organic & Biomolecular Chemistry,
Год журнала:
2024,
Номер
22(22), С. 4502 - 4507
Опубликована: Янв. 1, 2024
The
borrowing
hydrogen
methodology
(BH)
has
emerged
as
a
powerful
tool
for
the
rapid
construction
of
C-C
bonds,
offering
greener
alternative
to
traditional
multi-step
syntheses.
This
involves
activation
inactivated
alcohols
followed
by
condensation
or
aldolization,
ultimately
leading
regeneration
saturated
product.
Herein,
we
report
C-alkylation
hindered
ketone
with
challenging
secondary
heterocyclic
alcohols.
Our
study
encompasses
optimization
reaction
conditions
using
either
an
iridium
ruthenium
catalyst
and
exploration
substrate
scope.
We
demonstrate
efficient
synthesis
substituted
pyrrolidines
piperidines
directly
from
triol
precursor,
showcasing
versatility
this
methodology.
Moreover,
illustrate
post-functionalization
BH
products,
significantly
broadening
their
chemical
utility.
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 18, 2024
A
facile,
cost-effective,
and
sustainable
synthesis
of
substituted
triazines
from
primary
alcohols
by
newly
synthesized
nickel
pincer-type
complexes
(1–3)
has
been
described.
Herein,
we
report
the
a
set
three
well-defined
Ni(II)
O^N^O
complexes,
structurally
characterized
analytical,
spectral,
X-ray
diffraction
techniques.
Further,
are
explored
as
efficient
catalysts
(4
mol
%)
for
construction
2,4,6-substituted
1,3,5-triazines
readily
available
via
an
acceptorless
dehydrogenative
coupling
(ADC)
strategy.
wide
range
triazine
derivatives
(33
examples)
benzamidine/guanidine
hydrochloride
with
maximum
isolated
yield
92%
under
mild
conditions,
eco-friendly
H2O
H2
gas
only
byproducts.
plausible
mechanism
proposed
based
on
sequence
control
experiments.
Interestingly,
short
antiulcer
drug
irsogladine
large-scale
2,4-diphenyl-6-(p-tolyl)-1,3,5-triazine
highlight
convenience
current
methodology.
European Journal of Organic Chemistry,
Год журнала:
2023,
Номер
26(46)
Опубликована: Сен. 29, 2023
Abstract
Benzo‐fused
five‐membered
N/O/S
heterocyclic
compounds,
such
as
indole,
benzofuran,
and
benzothiophene,
possessing
a
single
heteroatom,
have
important
applications
in
medicinal
chemistry,
agrochemistry,
material
chemistry.
Metal‐catalysed
reactions
are
well‐established
synthetic
pathways
for
the
formation
of
C−X
bonds,
enabling
direct
synthesis
heterocycles.
This
approach
offers
advantages
over
traditional
methods,
fewer
steps,
increased
atom
economy,
low
catalyst
loading,
regioselectivity,
stereoselectivity.
Due
to
their
widespread
use
pharmaceutical
industry,
C−N,
C−O,
C−S
bonds
has
gained
significant
attention.
article
focusses
on
metal‐catalysed
corresponding
mechanistic
approaches
N/O/S‐heterocycles,
particularly
reviewing
progress
past
five
years
discussing
unexplored
future
opportunities.
