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 Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(16), С. 12131 - 12140
Опубликована: Июль 28, 2023
Spiroannulation
of
oxindole-3-oxy
acrylates
with
ynones
involving
two
overlapping,
base
differentiated
cascades
has
been
observed.
Initial
exposure
and
oxindole
3-oxy
to
K2CO3
triggered
a
tandem
Michael-Michael
cascade
deliver
pair
spiroannulated
diastereomers.
Further
LiHMDS
led
deep
restructuring
through
second
multistep
stereoselective
recreation
the
C3
quaternary
center
furnish
3H-spiro[furan-2,3'-indolin]-2'-ones
functional
amplification
scrambling.
This
new
scaffold
can
be
directly
accessed
in
one-flask
operation
from
acrylates.
Organic Chemistry Frontiers,
Год журнала:
2023,
Номер
10(19), С. 4848 - 4853
Опубликована: Янв. 1, 2023
An
efficient
strategy
for
the
enantioselective
construction
of
spirodihydrofuran
oxindoles
with
vicinal
quaternary
stereocenters
was
first
developed
via
a
one-pot
Michael/iodization/S
N
2
nucleophilic
substitution
sequence.
Organic & Biomolecular Chemistry,
Год журнала:
2022,
Номер
20(11), С. 2282 - 2292
Опубликована: Янв. 1, 2022
Diethyl
mesoxalate
(DEMO)
exhibits
high
electrophilicity
and
accepts
the
nucleophilic
addition
of
a
less
acid
amide
to
afford
N,O-hemiacetal.
However,
our
research
showed
that
elimination
moiety
proceeded
more
easily
than
dehydration
upon
treatment
with
base.
This
problem
was
overcome
by
reacting
DEMO
an
in
presence
acetic
anhydride
efficiently
obtain
N,O-acetal.
Acetic
eliminated
leading
formation
N-acylimine
situ
N-Acylimine
is
also
electrophilic,
accepting
second
pyrrole
or
indole
form
α,α-disubstituted
malonates.
Subsequent
hydrolysis
followed
decarboxylation
resulted
(α-indolyl-α-acylamino)acetic
formation;
homologs
tryptophan.
Through
this
process,
serves
as
synthetic
equivalent
α,α-dicationic
facilitate
introduction
two
substituents.
The Journal of Organic Chemistry,
Год журнала:
2022,
Номер
88(22), С. 15540 - 15550
Опубликована: Сен. 16, 2022
A
straightforward
metal-free
oxa-Michael
cascade
[4
+
2]
annulation
reaction
was
established
between
isatin-derived
Morita–Baylis–Hillman
(Is-MBH)
alcohols
with
alkylidene
pyrazolones
to
access
structural
diverse
tetrahydro-dispiro[indolinone-3,2′-pyran-5′,4″-pyrazolone]
scaffolds
bearing
two
tertiary
and
quaternary
stereocenters.
The
Is-MBH
alcohol
utilized
as
an
donor
for
the
first
time
a
new
approach
in
highly
atom-economical
transformations.
This
method
offered
wide
range
of
bioinspired
novel
tetrahydro-dispirooxindole-pyran-pyrazolone
derivatives
excellent
yields
(up
96%)
diastereoselectivities
>20:1)
shorter
(15
min).
European Journal of Organic Chemistry,
Год журнала:
2022,
Номер
2022(45)
Опубликована: Окт. 31, 2022
Abstract
A
catalyst‐free
tandem
reaction
was
developed
for
the
clean
synthesis
of
spiro[2,3‐dihydrofuran‐3,3’‐oxindole]
derivatives
from
2‐(2‐oxoindolin‐3‐yl)malononitriles
and
aldehydes
in
water.
This
method
has
an
extensive
substrate
scope.
The
targeted
products
were
easily
isolated
by
filtration
high
yields
excellent
diastereoselectivities.
also
features
numerous
advantages,
including
step/atom
economy,
both
catalyst
additive‐free,
no
organic
solvents,
simple
work‐up,
short
times,
environmentally
friendly
conditions.
present
strategy
utilizes
conditions,
demonstrating
potential
application
pharmaceuticals
biologically
active
compounds.
Australian Journal of Chemistry,
Год журнала:
2024,
Номер
77(3)
Опубликована: Март 4, 2024
A
facile
oxidative
cyclization
of
β-ketothioamides
for
the
simultaneous
formation
a
compound
library
similar
to
natural
product
benzothiazole
derivatives
has
been
developed.
The
resulted
in
four
classes
previously
unknown
derivatives.
This
chemistry’s
versatility
adds
valuable
component
methodology
obtaining
Abstract
An
efficient
organocatalytic
cascade
vinylogous
Michael‐cyclization
to
construct
the
challenging
full
substituted
cyclohexa‐1,3‐dienes
has
been
developed.
Catalyzed
by
cinchona
alkaloids‐derived
thiourea
VIII
at
−60
°C,
products
were
obtained
as
a
single
diastereomer
with
two
contiguous
stereocenters
and
more
than
four
different
useful
functional
groups
in
moderate
good
yields
excellent
enantioselectivities.
