Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(32)
Опубликована: Май 23, 2024
Abstract
Sterically
hindered
pyridines
embedded
in
a
three‐dimensional
triptycene
framework
have
been
synthesized,
and
their
resolution
by
chiral
HPLC
enabled
access
to
unprecedented
enantiopure
exceeding
the
known
steric
limits.
The
design
principles
for
new
axially
pyridine
derivatives
are
then
described.
To
rationalize
associations
with
Lewis
acids
transition
metals,
comprehensive
determination
of
electronic
parameters
this
class
was
performed.
This
led
general
parameterization
(percent
buried
volume
%V
Bur
,
Tolman
cone
angle
θ,
He
8
_steric
descriptor)
large
set
two‐
derivatives.
These
shown
describe
quantitatively
interactions
carbon‐
boron‐centered
were
used
predict
ΔG°
association
prototypical
B(C
6
F
5
)
3
acid
widely
frustrated
pair
catalysis.
first
sterics
is
fundamental
basis
future
development
predictive
reactivity
models
guiding
applications
bulky
organocatalysis,
pairs,
transition‐metal
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 27, 2025
The
absolute
and
relative
configurations
of
bioactive
chiral
molecules
are
typically
relevant
to
their
biological
properties.
It
is
thus
highly
important
desirable
construct
all
possible
stereoisomers
a
lead
candidate
or
given
natural
compound.
Synergistic
dual
catalysis
has
been
recognized
as
reliable
synthetic
strategy
for
variety
predictable
stereodivergent
transformations.
Despite
the
impressive
progress
made
in
this
field,
carbon-carbon
bond-formation
reactions
involving
stabilized
nucleophiles
remain
elusive.
Herein,
we
report
an
iridium-
magnesium-catalyzed
one-pot
sequential
allylic
alkylation/nucleophilic
alkylation
cascade
process
synthesis
four
3,3'-disubstituted
oxindoles
through
three-component
reaction.
A
diverse
array
products
readily
prepared
with
high
functional
group
compatibility
good
yields
excellent
diastereo-
enantioselectivities.
Subsequently,
total
spirooxindole
alkaloid
trigolutes
B
D
accomplished
concise
unified
route
using
same
set
starting
materials.
Accounts of Chemical Research,
Год журнала:
2024,
Номер
unknown
Опубликована: Янв. 31, 2024
ConspectusTransition-metal-catalyzed
coupling
reactions
of
dienes
(such
as
1,3-dienes,
alkoxyallenes,
and
aminoallenes)
with
carbon
nucleophiles
have
proven
to
be
a
highly
effective
method
for
creating
Csp3–Csp3
bonds.
These
perfect
atom
economy
typically
occur
under
mild
reaction
conditions.
By
using
chiral
metal
complexes
catalysts,
it
is
possible
create
enantioenriched
molecules
bearing
allylic
stereocenters
high
enantioselectivities.
However,
challenges
arise
when
bonds
two
vicinal
are
constructed
through
this
type
reaction.
Due
the
inherent
diastereoselectivities,
only
kinetically
favored
diastereoisomers
(either
syn-
or
anti-product)
usually
obtained
transition-metal
catalyst
system.
Achieving
complementary
stereoisomers
selectivity,
which
require
complete
control
both
absolute
relative
configurations
multiple
centers
in
single
chemical
transformation,
impossible.Over
past
decade,
significant
advancements
been
made
stereodivergent
synthesis.
Notably,
iridium-related
synergistic
catalysis
has
rapidly
developed
alkylation
reactions.
these
systems
were
limited
alcohol
derivatives
electrophilic
partners.
Finding
ways
extend
use
other
types
crucial
issue
that
needs
addressed.In
2019,
we
reported
first
palladium-mediated
system
between
1,3-dienes
aldimine
esters.
Lately,
strategy
successful
accessing
diverse
substrate
patterns.
In
Account,
will
summarize
our
laboratory's
efforts
developing
range
palladium-involved
dienes.
We
discovered
several
systems,
including
Pd/Cu(Ag),
Pd/amine,
Pd/Lewis
base,
Pd/PTC.
Additionally,
dienes,
such
aminoallenes,
serve
suitable
partners
coupling.
processes
provide
an
efficient
constructing
scaffolds
stereocenters.
Density
functional
theory
(DFT)
calculations
performed
elucidate
mechanism
rationalize
origins
stereochemistry
some
systems.
Finally,
synthetic
application
methods
demonstrated
concise
total
synthesis
number
natural
products
bioactive
molecules.
It
anticipated
increasing
chemists
join
research
on
contribute
more
elegant
examples
area.
believe
future
development
further
push
boundary
asymmetric
find
innovative
applications
soon
synthesizing
complex
Abstract
Asymmetric
sequential
hydrogenations
of
α
‐methylene
γ
‐
or
δ
‐keto
carboxylic
acids
are
established
in
one‐pot
using
a
bimetallic
Ru/Ru
catalyst
system,
achieving
the
stereodivergent
synthesis
all
four
stereoisomers
both
chiral
and
‐lactones
with
two
non‐vicinal
carbon
stereocenters
high
yields
(up
to
99%)
excellent
stereoselectivities
>99%
ee
>20:1
dr).
The
compatibility
Ru
systems
is
investigated
detail,
it
found
that
basicity
reaction
system
plays
key
role
hydrogenation
processes.
protocol
can
be
performed
on
gram‐scale
low
loading
11000
S/C)
resulting
products
allow
for
many
transformations,
particularly
several
intermediates
useful
preparation
drugs
natural
products.
Chemical Science,
Год журнала:
2024,
Номер
unknown
Опубликована: Янв. 1, 2024
Four-component
reactions
at
room
temperature
delivered
C–N
atropisomeric
peptide
analogues
possessing
both
central
and
axial
chirality
with
complete
diastereocontrol.
Reactions
elevated
selectively
afforded
the
other
diastereoisomer.
JACS Au,
Год журнала:
2024,
Номер
4(11), С. 4445 - 4454
Опубликована: Окт. 14, 2024
The
development
of
chiroptical
molecular
switches
for
chiral
sensing,
data
communication,
optical
displays,
logic
gates,
and
asymmetric
catalysis
is
currently
a
vibrant
frontier
science
technology.
Herein,
we
report
practical
artificial
dynamic
system
based
on
1,2-diaxial
atropisomer.
Organocatalytic
parallel
kinetic
resolution
allows
the
divergent
synthesis
two
sets
stereoisomers
with
vicinal
C-C
N-N
axes
from
same
racemic
single-axis
substrates.
By
simply
varying
configuration
single
catalyst,
all
four
are
accessible.
successive
conduction
covalent
unlocking/locking
thermal-isomerization
processes
enables
sequential
switching
between
atropisomeric
states
electronic
circular
dichroism
signal
reversal,
providing
an
example
multistate
switches.
