ACS Catalysis,
Journal Year:
2020,
Volume and Issue:
10(21), P. 12898 - 12919
Published: Oct. 21, 2020
Transition-metal-catalyzed
C–H
bond
functionalization
has
known
a
rapid
evolution
in
the
last
years,
offering
modern
strategies
for
reaching
high
molecular
complexity
step-
and
atom-economical
way.
Despite
indisputable
advances,
selectivity
issues
still
remain,
given
ubiquity
of
bonds
on
molecules;
thus,
several
approaches
have
been
developed
to
tackle
this
challenge.
Among
them,
use
transient
directing
group
emerged
as
an
effective
tool,
circumventing
need
extra
synthetic
steps
install
then
cleave
molecule.
More
recently,
strategy
successfully
applied
even
more
challenging
transition-metal-catalyzed
enantioselective
functionalization.
This
review
will
highlight
discuss
main
advances
made
chiral
C(sp2)–H
C(sp3)–H
by
transition-metal
catalysis.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(39)
Published: Aug. 2, 2022
The
atroposelective
synthesis
of
atropisomers
with
vicinal
diaxes
remains
rare
and
challenging,
due
to
the
steric
influence
between
two
axes
their
unique
topology.
Herein,
we
disclose
a
single-step
construction
C-C
C-N
chiral
by
cyclopentadiene
(Cp)-free
cobalt-catalyzed
intramolecular
C-H
annulation,
providing
desired
diaxial
structures
decent
stereocontrols
both
(up
>99
%
ee
70
:
1
dr).
optically
pure
products
bearing
fluorophores
show
circular
polarized
luminescence
(CPL)
properties,
being
candidate
materials
for
potential
CPL
applications.
Atropisomerization
experiments
density
function
theory
(DFT)
calculations
are
conducted
study
rotational
barriers
rotation
pathways
diaxes.
Nature Communications,
Journal Year:
2022,
Volume and Issue:
13(1)
Published: Jan. 10, 2022
Abstract
Axially
chiral
styrenes
bearing
a
axis
between
sterically
non-congested
acyclic
alkene
and
an
aryl
ring
are
difficult
to
prepare
due
low
rotational
barrier
of
the
axis.
Disclosed
here
is
N
-heterocyclic
carbene
(NHC)
catalytic
asymmetric
solution
this
problem.
Our
reaction
involves
ynals,
sulfinic
acids,
phenols
as
substrates
with
NHC
catalyst.
Key
steps
involve
selective
1,4-addition
anion
acetylenic
acylazolium
intermediate
sequential
E
-selective
protonation
set
up
affords
axially
product
>
99:1
e.r
.,
20:1
/
Z
selectivity,
excellent
yields.
The
sulfone
carboxylic
ester
moieties
in
our
styrene
products
common
bioactive
molecules
catalysis.
Tetrahedron Chem,
Journal Year:
2022,
Volume and Issue:
1, P. 100009 - 100009
Published: March 1, 2022
Axial
chirality
is
historically
epitomized
by
biaryl
compounds
containing
rotationally
impeded
aryl-aryl
linkage.
As
the
field
of
atroposelective
catalysis
advances,
synthesis
and
application
less
common
scaffolds
such
as
alkenes
have
now
come
to
fore.
The
manifestation
axial
in
aryl
was
hypothesized
1928
first
resolution
achieved
nearly
a
decade
later.
However,
catalytic
asymmetric
construction
axially
chiral
open-chain
appeared
only
2017
which
ushered
renewed
focus
on
these
structures.
In
principle,
possess
an
alkene
group
tethered
at
one
end
stereogenic
axis,
greatly
reduces
overall
rigidity.
To
date,
atropisomers
with
C
(vinyl)-C
(aryl)
(vinyl)-heteroatom
bond
been
reported.
Considering
rapid
growth
synthetic
utility
alkenes,
this
review
intends
provide
historical
overview
discusses
new
developments.
It
hope
that
timely
discussion
would
motivate
continued
nascent
field.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(21)
Published: March 21, 2023
The
catalytic
asymmetric
construction
of
N-N
atropisomeric
biaryls
remains
a
formidable
challenge.
Studies
them
lag
far
behind
studies
the
more
classical
carbon-carbon
biaryl
atropisomers,
hampering
meaningful
development.
Herein,
first
palladium-catalyzed
enantioselective
C-H
activation
pyrroles
for
synthesis
atropisomers
is
presented.
Structurally
diverse
indole-pyrrole
possessing
chiral
axis
were
produced
with
good
yields
and
high
enantioselectivities
by
alkenylation,
alkynylation,
allylation,
or
arylation
reactions.
Furthermore,
kinetic
resolution
trisubstituted
heterobiaryls
sterically
demanding
substituents
was
also
achieved.
Importantly,
this
versatile
functionalization
strategy
enables
iterative
exquisite
selectivity,
expediting
formation
valuable,
complex,
atropisomers.
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.
ACS Catalysis,
Journal Year:
2023,
Volume and Issue:
13(4), P. 2565 - 2575
Published: Feb. 6, 2023
We
present
herein
an
unprecedented
stereoselective
synthesis
of
triaryl-2-pyrones
with
monoaxial
or
contiguous
diaxes
from
readily
available
starting
materials.
This
N-heterocyclic
carbene
catalysis
method
adopts
atroposelective
annulation
2-aryketones
ynals
under
oxidative
conditions.
The
includes
the
construction
one
two
axes
in
a
single
operation,
achieves
step
economy,
and
affords
axially
chiral
moderate
to
good
yields,
high
excellent
enantioselectivities.
DFT
calculations
relative
energies
stereoisomers
rotational
barriers
were
performed.
