Advanced Synthesis & Catalysis,
Год журнала:
2024,
Номер
366(22), С. 4715 - 4722
Опубликована: Авг. 15, 2024
Abstract
A
squaramide
moiety
was
introduced
at
the
C‐4
position
of
proline
to
afford
an
organocatalyst
that
served
as
a
stereocontrol
element
promote
asymmetric
Michael
addition
cyclic
ketones
maleimides.
variety
chiral
succinimides
were
obtained
by
conjugate
in
84–98%
yield
accompanied
58–96%
enantioselectivity.
The
results
also
include
interesting
contrast
facial
selectivity
observed
with
cyclohexanones
and
cycloheptanones,
whereas
desymmetrization
4‐alkyl
achieved
using
transformation.
Catalysts,
Год журнала:
2021,
Номер
11(8), С. 1013 - 1013
Опубликована: Авг. 22, 2021
Organocatalysts
are
abundantly
used
for
various
transformations,
particularly
to
obtain
highly
enantio-
and
diastereomeric
pure
products
by
controlling
the
stereochemistry.
These
applications
of
organocatalysts
have
been
topic
several
reviews.
emerged
as
one
very
essential
areas
research
due
their
mild
reaction
conditions,
cost-effective
nature,
non-toxicity,
environmentally
benign
approach
that
obviates
need
transition
metal
catalysts
other
toxic
reagents.
Various
types
including
amine
catalysts,
Brønsted
acids,
Lewis
bases
such
N-heterocyclic
carbene
(NHC)
cinchona
alkaloids,
4-dimethylaminopyridine
(DMAP),
hydrogen
bond-donating
gained
renewed
interest
because
regioselectivity.
In
this
review,
we
present
recent
advances
in
regiodivergent
reactions
governed
organocatalysts.
Additionally,
briefly
discuss
pathways
achieving
changes
conditions
solvents,
additives,
or
temperature.
Organic & Biomolecular Chemistry,
Год журнала:
2022,
Номер
20(36), С. 7151 - 7187
Опубликована: Янв. 1, 2022
Gold-catalyzed
hydroarylation
reaction
offers
new
pathways
for
producing
complex
organic
compounds
with
diverse
ring
sizes
in
a
highly
regio-
and
stereo-selective
approach
from
available
precursors
like
olefins,
alkynes,
arenes,
aryl
halides.
Abstract
The
Pictet‐Spengler
reaction
is
a
century
old
technique
for
the
construction
of
aza‐cycles,
which
has
been
extensively
researched
through
organocatalytic
methods
over
past
two
decades.
asymmetric
variant
this
gained
considerable
attention
because
enantioenriched
poly
heterocycles
accessed
process
are
prevalent
in
natural
products
and
bioactive
moleculesPrime
focus
review
systematic
chronological
assembly
enantioselective
P−S
catalyzed
by
different
types
organocatalysts.
Mechanistic
approaches
to
rationalize
induction
on
an
additional
flavor
article.
Importance
conventional
justified
synthesis
biologically
naturally
relevant
compounds
have
highlighted
as
well.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(12)
Опубликована: Янв. 23, 2024
Benzo-fused
nitrogen
heterocycles
are
common
features
of
bioactive
molecules,
and
the
enantioselective
synthesis
their
substituted
analogues
is
an
important
goal.
In
this
paper
we
demonstrate
a
practical
mechanistically
intriguing
approach
to
1-arylbenzazepines
analogues.
The
reaction
sequence
starts
with
asymmetric
migratory
ring
expansion
indoline,
tetrahydroquinoline,
or
tetrahydrobenzazepine
ureas
on
treatment
chiral
lithium
amide
base.
Treatment
ring-expanded
acid
triggers
two-atom
contraction-an
'azatropic
shift'
in
which
one
urea
displaces
other-with
almost
complete
retention
stereochemistry.
Aminolysis
products
provides
enantioenriched
1-aryl-tetrahydrobenzazepine
derivatives
congeners,
including
analogue
intermediate
drug
solifenacin.
Deuteration,
situ
IR,
DFT
studies
provide
evidence
for
mechanisms
steps.
Organic Chemistry Frontiers,
Год журнала:
2022,
Номер
9(21), С. 6077 - 6113
Опубликована: Янв. 1, 2022
This
review
provides
a
journey
of
the
catalyst
usage
for
enantioselective
conjugate
addition
nitroalkanes
to
electron-poor
olefins
from
early
attempts
latest
achievements.
Selected
applications
are
also
reported.
Herein,
we
report
a
novel
squaramide
containing
chiral
bifunctional
N-heterocyclic
carbene
(NHC)
and
its
utilization
in
developing
asymmetric
intramolecular
conjugate
addition
involving
noncovalent
interaction.
Via
concomitant
activation
of
both
electrophilic
nucleophilic
centers
substrates,
the
reaction
proceeds
through
well-organized
transition
state,
thereby
affording
products
with
up
to
94%
ee
broad
scope.
The
process
is
found
be
scalable.
initial
mechanistic
study
supports
nature
newly
designed
NHC.
International Journal of Molecular Sciences,
Год журнала:
2022,
Номер
23(14), С. 7685 - 7685
Опубликована: Июль 12, 2022
(1)
Background:
carbonic
anhydrases
(CAs)
are
attractive
targets
for
the
development
of
new
anticancer
therapies;
in
particular,
CAs
IX
and
XII
isoforms
overexpressed
numerous
tumors.
(2)
Methods:
following
tail
approach,
we
have
appended
a
hydrophobic
aromatic
to
pharmacophore
responsible
CA
inhibition
(aryl
sulfonamide,
coumarin).
As
linker,
used
squaramides,
featured
with
strong
hydrogen
bond
acceptor
donor
capacities.
(3)
Results:
Starting
from
easily
accessible
dimethyl
squarate,
title
compounds
were
successfully
obtained
as
crystalline
solids,
avoiding
use
chromatographic
purifications.
Interesting
valuable
SARs
could
be
upon
modification
length
hydrocarbon
chain,
position
sulfonamido
moiety,
distance
aryl
sulfonamide
scaffold
squaramide,
stereoelectronic
effects
on
ring,
well
number
type
substituents
C-3
C-4
positions
coumarin.
(4)
Conclusions:
For
sulfonamides,
best
profile
was
achieved
m-substituted
derivative
11
(Ki
=
29.4,
9.15
nM,
XII,
respectively),
improved
selectivity
compared
acetazolamide,
standard
drug.
Coumarin
derivatives
afforded
an
outstanding
>
10,000
nM
I,
II);
lead
compound
(16c)
inhibitor
19.2,
7.23
respectively).
Docking
simulations
revealed
key
ligand-enzyme
interactions.
Beilstein Journal of Organic Chemistry,
Год журнала:
2023,
Номер
19, С. 956 - 981
Опубликована: Июнь 28, 2023
The
aza-Friedel–Crafts
reaction
allows
an
efficient
coupling
of
electron-rich
aromatic
systems
with
imines
for
the
facile
incorporation
aminoalkyl
groups
into
ring.
This
has
a
great
scope
forming
aza-stereocenters
which
can
be
tuned
by
different
asymmetric
catalysts.
review
assembles
recent
advances
in
reactions
mediated
organocatalysts.
mechanistic
interpretation
origin
stereoselectivity
is
also
explained.
Advanced Synthesis & Catalysis,
Год журнала:
2023,
Номер
365(19), С. 3234 - 3240
Опубликована: Июль 21, 2023
Abstract
The
potential
of
phosphites
as
nucleophiles
for
the
asymmetric
synthesis
chiral
chromene
derivatives
has
been
overlooked
in
literature.
Herein,
we
report
a
promising
approach
via
organocatalyzed
phospha‐Michael
addition
to
iminochromenes,
using
bifunctional
squaramide,
which
gives
access
chromenylphosphonates,
an
interesting
family
bioactive
compounds.
Our
optimized
protocol
provides
very
good
reactivity,
affording
yields
up
95%
and
with
products
exhibiting
enantiomeric
excess
98%.
