Atropisomerism,
arising
from
hindered
rotation
about
single
bonds,
is
a
crucial
element
of
molecular
chirality
with
far-reaching
implications
across
scientific
disciplines.
This
opening
chapter
elucidates
the
foundational
concepts
underpinning
atropisomerism
and
chirality,
laying
groundwork
for
subsequent
discussions.
Furthermore,
it
outlines
diverse
atroposelective
synthetic
methodologies,
encompassing
metal-based
organocatalytic
oxidative
coupling,
cross-coupling,
ring-opening
reactions,
which
receive
detailed
consideration
in
chapters,
thus
underscoring
breadth
research
this
domain.
Recent
advancements
field
are
highlighted,
underlining
growing
recognition
atropisomerism's
multifaceted
applications.
Additionally,
addresses
persistent
challenges
impeding
further
control
synthesis,
along
its
expanding
applications
drug
industry
development.
Chemical Reviews,
Journal Year:
2023,
Volume and Issue:
123(17), P. 10641 - 10727
Published: Aug. 28, 2023
Enantiomers,
where
chirality
arises
from
restricted
rotation
around
a
single
bond,
are
atropisomers.
Due
to
the
unique
nature
of
origins
their
chirality,
synthetic
strategies
access
these
compounds
in
an
enantioselective
manner
differ
those
used
prepare
enantioenriched
containing
point
arising
unsymmetrically
substituted
carbon
center.
In
particular
stereodynamic
transformations,
such
as
dynamic
kinetic
resolutions,
thermodynamic
and
deracemizations,
which
rely
on
ability
racemize
or
interconvert
enantiomers,
promising
set
transformations
optically
pure
late
stage
sequence.
Translation
approaches
with
atropisomers
requires
expanded
toolbox
for
epimerization/racemization
provides
opportunity
develop
new
conceptual
framework
synthesis
compounds.
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: Jan. 12, 2024
Abstract
We
report
an
organocatalyst
that
combines
a
triazolium
N-heterocyclic
carbene
(NHC)
with
squaramide
as
hydrogen-bonding
donor
(HBD),
which
can
effectively
catalyze
the
atroposelective
ring-opening
of
biaryl
lactams
via
unique
amide
C–N
bond
cleavage
mode.
The
free
species
attacks
carbonyl,
forming
axially
chiral
acyl-azolium
intermediate.
Various
amines
be
accessed
by
this
methodology
up
to
99%
ee
and
yield.
By
using
mercaptan
catalyst
turnover
agent,
resulting
thioester
synthon
transformed
into
several
interesting
atropisomers.
Both
control
experiments
theoretical
calculations
reveal
crucial
role
hybrid
NHC-HBD
skeleton,
activates
H-bonding
brings
it
spatially
close
centre.
This
discovery
illustrates
potential
chimera
demonstrates
complementary
strategy
for
activation
manipulation.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(9), P. 6283 - 6293
Published: Feb. 21, 2024
We
herein
introduce
biarylhemiboronic
esters
as
a
new
type
of
bridged
biaryl
reagent
for
asymmetric
synthesis
axially
chiral
structures,
and
the
palladium-catalyzed
Suzuki-Miyaura
cross-coupling
is
developed.
This
dynamic
kinetic
atroposelective
coupling
reaction
exhibits
high
enantioselectivity,
good
functional
group
tolerance,
broad
substrate
scope.
The
synthetic
application
current
method
was
demonstrated
by
transformations
product
programmed
polyarene.
Preliminary
mechanistic
studies
suggested
that
proceeded
via
an
enantio-determining
transmetalation
step.
Advanced Synthesis & Catalysis,
Journal Year:
2024,
Volume and Issue:
366(6), P. 1269 - 1284
Published: Jan. 31, 2024
Abstract
Axially
chiral
architectures
exist
widely
in
natural
products,
biologically
relevant
molecules,
ligands
and
catalysts
as
well
functional
materials.
Therefore,
catalytic
asymmetric
synthesis
of
atropisomers
has
become
one
the
most
fast‐growing
fields
community
chemistry
rapid
advances
have
occurred.
Among
different
methods
reported,
organocatalytic
atroposelective
dynamic
kinetic
resolution
(DKR)
involving
ring
manipulations
stands
out
a
cutting‐edge
technology
to
construct
axial
chirality
from
point
atom/step
economy.
In
this
DKR
strategy,
configurational
lability
starting
materials
originates
chirally‐labile
structure
cyclic
substrates/intermediates
or
transient
formation
through
noncovalent
interactions
acyclic
substrates.
The
two
material
are
equilibrium
reaction
medium,
ensuring
constant
transformation
less
reactive
atropisomer
into
more
one,
then
single
enantiopure
product
presence
an
appropriate
organocatalyst.
This
review
summarizes
recent
advancements
on
topic,
including
their
scopes,
limitations,
mechanisms,
applications
provides
some
insights
further
developments.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(12), P. 2403 - 2408
Published: March 19, 2024
The
catalytic
atroposelective
synthesis
of
axially
chiral
heterobiaryls
was
first
developed
through
the
direct
one-step
dynamic
kinetic
condensation
reaction
with
simple
transformation
C═O
bond
to
C═N
bond,
delivering
a
series
novel
heterobiaryl
oxime
ethers.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(39)
Published: June 20, 2023
The
development
of
catalytic
asymmetric
reaction
with
water
as
the
reactant
is
challenging
due
to
reactivity-
and
stereoselectivity-control
issues
resulted
from
low
nucleophilicity
small
size
water.
We
disclose
herein
a
chiral
phosphoric
acid
(CPA)
catalyzed
atroposelective
ring-opening
biaryl
oxazepines
A
series
undergo
CPA
hydrolysis
in
highly
enantioselective
manner.
key
for
success
this
use
new
SPINOL-derived
catalyst
high
reactivity
oxazepine
substrates
towards
under
acidic
conditions.
Density
functional
theory
calculations
suggest
that
proceeds
via
dynamic
kinetic
resolution
pathway
addition
imine
group
both
enantio-
rate-determining.
European Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
27(28)
Published: May 16, 2024
Abstract
Axially
chiral
biaryl
scaffolds
are
important
in
pharmaceuticals,
natural
products,
and
asymmetric
synthesis.
Atroposelective
ring‐opening
of
configurationally
labile
reagents
via
dynamic
kinetic
transformation
provides
a
valuable
approach
to
access
axially
atropisomers.
This
review
summarizes
seminal
contributions
recent
advancements
on
this
topic
based
the
use
different
types
reagents.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(46), P. 8252 - 8257
Published: Nov. 13, 2023
Disclosed
here
is
NHC-catalyzed
direct
intermolecular
trapping
of
the
ketone
oxygen
atom
with
acyl
azolium
intermediate.
The
overall
reaction
a
dynamic
kinetic
resolution
process
that
converts
to
corresponding
enol
ester
well-controlled
axial
chirality.
Our
eventually
affords
non-C2-symmetric
binaphthyl
derivatives
important
applications,
such
as
in
area
asymmetric
catalysis.
Advanced Synthesis & Catalysis,
Journal Year:
2023,
Volume and Issue:
365(19), P. 3392 - 3396
Published: Sept. 14, 2023
Abstract
An
additive‐
and
external
oxidant‐free
reaction
of
cyclopropanols,
DABCO
⋅
(SO
2
)
diaryliodonium
salts
in
aqueous
phase
is
described.
This
proceeds
under
mild
conditions,
affording
bioactive
aryl
substituted
γ‐keto
sulfones
36%‐90%
yields
with
good
functional
group
tolerance.
through
a
sulfinate
intermediate,
which
undergoes
nucleophilic
salts,
giving
rise
to
corresponding
sulfones.
Chemistry - A European Journal,
Journal Year:
2024,
Volume and Issue:
30(39)
Published: May 7, 2024
Axially
chiral
cycloalkylidenes
are
interesting
but
less
developed
axially
molecules.
Here,
a
bispidine-based
amine
catalytic
system
was
to
promote
efficiently
the
asymmetric
Knoevenagel
condensation
of
N-protected
oxindoles
and
benzofuranones
with
4-substituted
cyclohexanones.
A
variety
alkylidenecycloalkanes
stable
axial
chirality
were
obtained
in
good
yields
fairly
er
(enantiomeric
ratio).
Based
on
absolute
configuration
determination
product
DFT
calculations,
possible
mechanism
stereoselective
induction
proposed.
