Addressing
the
asymmetric
synthesis
of
oxindole-based
a-amino
boronic
acids,
instead
expected
products
we
disclosed
efficient
homocoupling
N-
tert
-butanesulfinyl
imines,
with
generation
chiral,
quaternary
1,2-diamines
in
a
mild
and
completely
stereoselective
way.
The
obtained
3,3′-bisoxindoles
derivatives
were
fully
characterised
by
NMR
single-crystal
X-ray
diffraction
analysis
proved
to
be
single
diastereoisomers
atropoisomers.
A
plausible
mechanism
for
one-pot
Cu(II)-catalysed
Bpin-addition
isatin-derived
ketimine
subsequent
is
detailed.
The
enantioselective
formal
(3
+
2)
cyclization
and
sequential
reaction
of
2-malononitrile-substituted
oxindoles
with
benzaldehydes
ortho-aminobenzaldehydes
were
achieved
by
chiral
N,N′-dioxide/metal
complex
Lewis
acid
catalysts.
This
protocol
supplies
facile
efficient
access
to
highly
functionalized
dihydrofuran-
azepine-based
spirooxindoles.
Based
on
the
control
experiments
deuterium
labeling
studies,
interconversion
diastereomeric
intermediates
under
conditions
reversible
1,5-H
transfer
step
disclosed.
Advanced Synthesis & Catalysis,
Год журнала:
2021,
Номер
363(13), С. 3283 - 3289
Опубликована: Апрель 23, 2021
Abstract
Carbon
bisnucleophiles
are
important
building
blocks
in
organic
synthesis
and
have
widespread
applications
the
construction
of
carbocyclic
compounds.
Among
them,
1,2‐carbon
bisnucleophile
has
been
much
less
explored.
Herein,
we
developed
a
[2+3]
annulation
2‐(2‐oxoindolin‐3‐yl)malononitrile
with
2‐nitroallylic
acetates,
where
served
as
new
type
bisnucleophile.
Remarkably,
reaction
exhibits
exclusive
chemo‐
regioselectivity.
A
Michael
addition/S
N
2
mechanism
was
proposed
to
avoid
“anti‐Baldwin”
cyclization.
This
stereoselective
strategy
provides
facile
synthetic
route
for
series
spirocyclopentane
oxindole
derivatives
containing
three
stereogenic
centers.
magnified
image
Advanced Synthesis & Catalysis,
Год журнала:
2021,
Номер
363(13), С. 3267 - 3282
Опубликована: Апрель 21, 2021
Abstract
A
synthetic
procedure,
catalysed
by
Ir(ppy)
3
under
visible‐light
irradiation,
for
the
chemodivergent
synthesis
of
2,3‐dihydrofurans
(
)
or
β,γ‐unsaturated
ketones
7
starting
from
α‐halo
1
and
alkenes
2
has
been
developed.
The
mild
reaction
conditions
redox‐neutral
nature
process
make
it
particularly
sustainable
avoiding
use
both
sacrificial
reactants
stoichiometric
strong
oxidants.
Careful
experimental
investigations,
supported
DFT
calculations,
allowed
to
disclose
in
details
a
possible
mechanistic
pathway
direct
chemodivergently
either
toward
,
depending
not
only
on
substrates,
but
also
choice
conditions.
magnified
image
Organic Letters,
Год журнала:
2022,
Номер
24(33), С. 6197 - 6201
Опубликована: Авг. 17, 2022
Developing
efficient
strategies
to
synthesize
spirocyclopenteneoxindoles
is
an
attractive
target
due
their
potential
biological
activity.
This
work
described
the
thiourea/silver
dual
catalytic
(3
+
2)/Conia-ene
type
reaction
of
2-(2-oxoindolin-3-yl)malononitrile
with
ortho-ethynyl
substituted
nitrostyrene.
The
features
mild
conditions
and
good
atom-
step-economy.
Three
new
C–C
bonds
were
formed
within
one
synthetic
step,
providing
indane-fused
in
yields,
excellent
chemo-,
regio-,
stereoselectivity.
Organic Chemistry Frontiers,
Год журнала:
2023,
Номер
10(16), С. 4061 - 4067
Опубликована: Янв. 1, 2023
An
enantioselective
construction
of
spiro[1-indanone-dihydrofurans]
has
been
accomplished
through
zinc-catalyzed
[3
+
2]
annulation
via
a
Brønsted
base
and
Lewis
acid
cooperative
activation
model.
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(17), С. 12716 - 12724
Опубликована: Авг. 14, 2024
On
the
basis
of
a
novel
umpolung
strategy,
an
efficient
l-amino
acid
ester-mediated
in
situ
reduction
2-(2-oxoindolin-3-ylidene)malononitrile
and
sequential
nucleophilic
addition/cyclization
cascade
reaction
is
reported.
Various
densely
substituted
cyclopentene
bispirooxindoles
dihydrofuran
with
two
quaternary
spirocenters
were
constructed
high
yields
(≤93%)
excellent
diastereoselectivities
(>20:1
dr).
The
method
has
advantages
readily
available
starting
materials,
mild
conditions,
one-pot
process,
metal-free
biomimetic
reducing
agent,
wide
substrate
scope,
operational
simplicity
(single
filtration
without
column
chromatography).
Beilstein Journal of Organic Chemistry,
Год журнала:
2022,
Номер
18, С. 669 - 679
Опубликована: Июнь 14, 2022
The
tri(n-butyl)phosphine-catalyzed
reaction
of
isatylidene
malononitriles
and
bis-chalcones
in
chloroform
at
65
°C
afforded
functionalized
spiro[cyclohexane-1,3'-indolines]
good
yields
with
diastereoselectivity.
On
the
other
hand,
3-(ethoxycarbonylmethylene)oxindoles
gave
different
regioselectivity.
Additionally,
tri(n-butyl)phosphine-promoted
domino
annulation
isatins
ethyl
cyanoacetates
produced
spiro[indoline-3,2'-furan-3',3''-indolines]
satisfactory
yields.
