The Journal of Organic Chemistry,
Год журнала:
2022,
Номер
87(9), С. 6025 - 6037
Опубликована: Апрель 18, 2022
A
dearomatization
process
of
3-nitroindoles
enabled
using
palladium-catalyzed
decarboxylative
[4
+
2]
cycloaddition
either
2-alkylidenetrimethylene
carbonates
or
2-(hydroxymethyl)-3-arylallyl
has
been
developed,
affording
a
wide
range
indoline-fused
tetrahydropyrans
in
good
yields
with
excellent
diastereoselectivities.
This
reaction
features
substrate
scope
and
mild
conditions
represents
the
first
example
application
π-allyl
palladium
1,4-[O,C]-dipole
species
for
dearomative
electron-deficient
heteroarenes.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 28, 2025
The
cycloaddition
reactions
of
bicyclo[1.1.0]butanes
with
alkenes,
imines,
nitrones,
or
aziridines
have
served
as
an
efficient
platform
to
create
conformationally
restricted
saturated
bicyclic
scaffolds.
However,
the
use
readily
available
aromatics
in
such
reactions,
especially
asymmetric
manner,
remains
underexplored.
Herein,
we
report
a
highly
regio-
and
enantioselective
dearomative
[2π
+
2σ]
photocycloaddition
reaction
between
naphthalene
derivatives
bicyclo[1.1.0]butanes,
enabled
by
Gd(III)
catalysis.
Bicyclo[1.1.0]butanes
naphthalenes
adorned
diverse
array
functional
groups
are
well-tolerated
under
mild
conditions,
affording
enantioenriched
pharmaceutically
important
bicyclo[2.1.1]hexanes
30–96%
yields
81–93%
ee
12:1
→
>20:1
rr.
synthetic
versatility
this
is
further
demonstrated
facile
removal
directing
group
derivatizations
dearomatized
product.
UV–vis
absorption
spectroscopy
studies
suggest
involvement
excited
species
process.
Chemical Communications,
Год журнала:
2020,
Номер
57(1), С. 27 - 44
Опубликована: Ноя. 25, 2020
3-Nitroindoles
behave
as
electron-poor
aromatic
compounds
and
react
toward
a
number
electron-rich
species.
This
feature
article
presents
an
overview
of
this
reactivity,
mainly
in
(formal)
dearomatizing
cycloaddition
reactions.
Journal of the American Chemical Society,
Год журнала:
2021,
Номер
143(40), С. 16502 - 16511
Опубликована: Сен. 28, 2021
Indole
dearomatization
is
an
important
strategy
to
access
indolines:
a
motif
present
in
variety
of
natural
products
and
biologically
active
molecules.
Herein,
method
for
transition-metal
catalyzed
regioselective
dearomative
arylboration
indoles
generate
diverse
indolines
presented.
The
accomplishes
intermolecular
simple
through
migratory
insertion
pathway
on
substrates
that
lack
activating
or
directing
groups
the
C2-
C3-positions.
Synthetically
useful
C3-borylated
can
be
accessed
change
N-protecting
group
high
regio-
diastereoselectivities
(up
>40:1
rr
dr)
from
readily
available
starting
materials.
Additionally,
origin
regioselectivity
was
explored
experimentally
computationally
uncover
remarkable
interplay
between
carbonyl
orientation
indole,
electronics
C2–C3
π-bond,
sterics.
enabled
first
enantioselective
synthesis
(−)-azamedicarpin.
Organic Letters,
Год журнала:
2021,
Номер
23(21), С. 8600 - 8605
Опубликована: Окт. 21, 2021
An
enantioselective
dearomative
1,3-dipolar
cycloaddition
of
2-nitrobenzothiophenes
and
isatin-derived
azomethine
ylides
with
a
bifunctional
hydrogen-bonding
thiourea
catalyst
was
established,
giving
polyheterocyclic
compounds
in
excellent
results
(up
to
99%
yield,
>20:1
dr
for
all
cases
up
ee).
The
enantioselectivity
could
be
reversed
by
the
squaramide
containing
same
chiral
source
as
catalyst.
DFT
calculations
revealed
origin
observed
stereochemistry
reversal
enantioselectivity.
Organic Letters,
Год журнала:
2022,
Номер
24(3), С. 826 - 831
Опубликована: Янв. 14, 2022
We
disclose
a
Ag-catalyzed
asymmetric
interrupted
Barton–Zard
reaction
of
α-aryl-substituted
isocyanoacetates
with
2-
and
3-nitroindoles,
which
enables
the
dearomatization
nitroindoles
hence
offers
rapid
access
to
an
array
optically
active
tetrahydropyrrolo[3,4-b]indole
derivatives
bearing
three
contiguous
stereogenic
centers,
including
two
tetrasubstituted
chiral
carbon
atoms
pretty
outcomes
(up
99%
yield,
91:9
dr,
96%
ee).
The
synthetic
potential
protocol
was
showcased
by
gram-scale
versatile
transformations
product.
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(18), С. 10314 - 10321
Опубликована: Апрель 26, 2023
Samarium
diiodide
(SmI2)
mediated
reductive
coupling
reactions
are
powerful
methods
for
the
construction
of
carbon-carbon
bond
in
organic
synthesis.
Despite
extensive
development
recent
decades,
successful
examples
corresponding
asymmetric
remained
scarce,
probably
due
to
involvement
highly
reactive
radical
intermediates.
In
this
Article,
we
report
an
enantioselective
dearomatization
indoles
via
SmI2-mediated
intermolecular
with
ketones.
The
utilization
samarium
reductant
supported
by
chiral
tridentate
aminodiol
ligands
allows
facile
synthesis
indoline
molecules
bearing
two
contiguous
stereogenic
centers
high
yields
(up
99%)
and
stereoselectivity
99:1
er
>20:1
dr).
Combined
experimental
computational
investigations
suggested
that
parallel
single-electron
transfer
each
substrate
from
radical-radical
recombination
manner,
which
is
a
unique
mechanistic
scenario
reactions.
Organic Letters,
Год журнала:
2024,
Номер
26(15), С. 3189 - 3194
Опубликована: Апрель 8, 2024
A
new
umpolung
approach
to
the
C3–H
functionalization
of
indoles
with
diverse
nucleophiles
based
on
intermediate
formation
I(III)
reagents
is
described.
The
3,5-dimethylisoxazol-4-yl
auxiliary
allows
for
selective
indole
transfer
under
catalyst-free
conditions,
which
was
impossible
using
previously
reported
reagents.
Combining
mildness
transition-metal-free
conditions
and
high
reactivity
hypervalent
iodine
reagents,
this
protocol
tolerates
various
functional
groups
provides
access
that
are
difficult
prepare
conventionally.
Organic Letters,
Год журнала:
2024,
Номер
26(15), С. 3310 - 3315
Опубликована: Апрель 8, 2024
A
catalyst
system
consisting
of
a
chiral
phosphoramidite
ligand
and
Pd2(dba)3·CHCl3
causes
the
decarboxylation
5-vinyloxazolidine-2,4-diones
to
generate
amide-containing
aza-π-allylpalladium
1,3-dipole
intermediates,
which
are
capable
triggering
dearomatization
3-nitroindoles
for
diastereo-
enantioselective
[3+2]
cycloaddition,
leading
formation
series
highly
functionalized
pyrroloindolines
containing
three
contiguous
stereogenic
centers
with
excellent
results
(up
99%
yield,
88:12
dr,
96%
ee).
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Июнь 20, 2024
Photocatalysis
holds
a
pivotal
position
in
modern
organic
synthesis,
capable
of
inducing
novel
reactivities
under
mild
and
environmentally
friendly
reaction
conditions.
However,
the
merger
photocatalysis
transition-metal-catalyzed
asymmetric
C-H
activation
as
an
efficient
sustainable
method
for
construction
chiral
molecules
remains
elusive
challenging.
Herein,
we
develop
cobalt-catalyzed
enantioselective
enabled
by
visible-light
photoredox
catalysis,
providing
synergistic
catalytic
strategy
dearomatization
indoles
with
high
levels
enantioselectivity
(96
%
to
>99
ee).
Mechanistic
studies
indicate
that
excited
photocatalyst
was
quenched
divalent
cobalt
species
presence
Salox
ligand,
leading
formation
catalytically
active
Co(III)
complex.
Moreover,
stoichiometric
reactions
cobaltacycle
intermediate
indole
suggest
irradiation
visible
light
also
play
critical
role
step.