Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(45)
Published: July 11, 2024
Abstract
Here,
we
report
a
strategy
enabling
triple
switchable
chemo‐,
regio‐,
and
stereodivergence
in
newly
developed
palladium‐catalyzed
cycloadditions
of
allenes.
An
asymmetric
pseudo‐stereodivergent
cycloaddition
allenes
bearing
primary
leaving
group
at
the
α
‐position,
where
dynamic
kinetic
hydroalkoxylation
racemic
unactivated
was
enantio‐determining
step,
is
realized,
providing
four
stereoisomers
[(
Z,R
),
(
Z,S
E,S
E,R
)]
containing
di‐substituted
alkene
scaffold
stereogenic
center.
By
tuning
reaction
conditions,
mechanistically
distinctive
uncovered
selectively
with
same
set
substrates.
switching
position
allenes,
involving
an
intermolecular
O‐attack
disclosed.
Diverse
mechanisms
reactions
enable
rapid
access
to
structurally
stereochemically
diverse
3,4‐dihydro‐2
H
‐1,4‐benzoxazines
high
efficiency
selectivity.
Chemical Reviews,
Journal Year:
2024,
Volume and Issue:
124(14), P. 8657 - 8739
Published: July 2, 2024
Chiral
phosphorus
ligands
play
a
crucial
role
in
asymmetric
catalysis
for
the
efficient
synthesis
of
useful
optically
active
compounds.
They
are
largely
categorized
into
two
classes:
backbone
chirality
and
P-stereogenic
ligands.
Most
reported
belong
to
former
class.
Privileged
ones
such
as
BINAP
DuPhos
frequently
employed
wide
range
catalytic
transformations.
In
contrast,
latter
class
has
remained
small
family
many
years
mainly
because
their
synthetic
difficulty.
The
late
1990s
saw
emergence
novel
with
superior
enantioinduction
ability
Rh-catalyzed
hydrogenation
reactions.
Since
then,
numerous
have
been
synthesized
used
This
Review
summarizes
thus
far,
including
stereochemical
electronic
properties
that
afford
high
excellent
enantioselectivities.
Examples
reactions
use
this
described
together
applications
construction
key
intermediates
natural
products
therapeutic
agents.
literature
covered
dates
back
1968
up
until
December
2023,
centering
on
studies
published
later
years.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(13), P. 9241 - 9251
Published: March 19, 2024
Much
attention
has
been
focused
on
the
catalytic
asymmetric
creation
of
single
chiral
centers
or
two
adjacent
stereocenters.
However,
construction
nonadjacent
stereocenters
is
significant
importance
but
challenging
because
lack
remote
induction
models.
Herein,
based
a
C═C
bond
relay
strategy,
we
report
synergistic
Pd/Cu-catalyzed
1,5-double
model.
All
four
stereoisomers
target
products
bearing
1,5-nonadjacent
involving
both
allenyl
axial
and
central
chirality
could
be
obtained
divergently
by
simply
changing
combination
catalysts
with
different
configurations.
Control
experiments
DFT
calculations
reveal
novel
mechanism
1,5-oxidative
addition,
contra-thermodynamic
η3-allyl
palladium
shift,
conjugate
nucleophilic
substitution,
which
play
crucial
roles
in
control
reactivity,
regio-,
enantio-,
diastereoselectivity.
It
expected
that
this
strategy
may
provide
general
protocol
for
synthesis
structural
motifs
distant
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(22), P. 15453 - 15463
Published: May 25, 2024
In
contrast
to
the
asymmetric
synthesis
of
molecules
with
a
single
stereocenter
or
1,2-adjacent
stereocenters,
simultaneous
construction
acyclic
1,3-nonadjacent
stereocenters
via
catalyst
in
an
enantioselective
and
diastereoselective
manner
remains
formidable
challenge.
Here,
we
demonstrate
diastereodivergent
through
Ni-catalyzed
reductive
cyclization/cross-coupling
alkene-tethered
aryl
bromides
α-bromoamides,
which
represents
major
remaining
stereochemical
challenge
cyclization/difunctionalization
alkenes.
Using
Ming-Phos
as
ligand,
diverse
set
oxindoles
containing
were
obtained
high
levels
enantio-
diastereoselectivity.
Mechanistic
experiments
density
functional
theory
calculations
indicate
that
magnesium
salt
plays
key
role
controlling
Furthermore,
another
complementary
stereoisomeric
products
constructed
from
same
starting
materials
using
Ph-Phox
ligand.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(35)
Published: May 16, 2024
Abstract
The
construction
of
chiral
motifs
containing
nonadjacent
stereocenters
in
an
enantio‐
and
diastereoselective
manner
has
long
been
a
challenging
task
synthetic
chemistry,
especially
with
respect
to
their
stereodivergent
synthesis.
Herein,
we
describe
protocol
that
enables
the
1,5/1,7‐nonadjacent
tetrasubstituted
through
Pd/Cu‐cocatalyzed
Heck
cascade
reaction.
Notably,
C=C
bond
relay
strategy
involving
shift
π‐allyl
palladium
intermediate
was
successfully
applied
asymmetric
1,7‐nonadjacent
stereocenters.
current
method
allows
for
efficient
preparation
molecules
bearing
two
privileged
scaffolds,
oxindoles
non‐natural
α‐amino
acids,
good
functional
group
tolerance.
full
complement
four
stereoisomers
products
could
be
readily
accessed
by
simple
combination
metal
catalysts
different
enantiomers.
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
14(13), P. 9940 - 9954
Published: June 19, 2024
Metal-catalyzed
allenylic
substitution
reactions
where
allenes
serve
as
electrophilic
precursors
have
been
recognized
a
rapid
way
for
novel
allene
construction.
On
the
contrary,
chemistry
in
which
act
nucleophiles
has
far
less
investigated,
especially
powerful
platform
such
metal-catalyzed
allylic
alkylation
reactions.
We
herein
describe
two
unprecedented
palladium-catalyzed
of
an
nucleophile.
In
first
reaction,
using
vinyloxazolidinones
allyl
precursor,
asymmetric
allylation
trisubstituted
allenones
worked
well
to
prepare
array
axially
chiral
tetrasubstituted
allenes.
Mechanistic
studies
and
density
functional
theory
(DFT)
calculations
indicated
that
weak
hydrogen-bonding
interaction
between
acidic
C(sp2)–H
allenone
nitrogen
anion
π-azaallyl-Pd
species
is
key
success
stereocontrol.
This
reaction
revealed
intriguing
reactivity
nucleophilic
time.
second
with
use
allenylethylene
carbonates
π-oxyallyl-Pd
precursors,
presented
unique
under
different
conditions
provide
divergent
synthetic
access
(E)-
(Z)-allenyl
diene
products.
Interestingly,
subsequent
sequential
intramolecular
cyclization/isomerization
(Z)-product
delivered
dihydrooxepine
derivatives
[5
+
2]
annulation
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
63(5)
Published: Dec. 15, 2023
The
construction
of
acyclic,
non-adjacent
1,3-stereogenic
centers,
prevalent
motifs
in
drugs
and
bioactive
molecules,
has
been
a
long-standing
synthetic
challenge
due
to
acyclic
nucleophiles
being
distant
from
the
chiral
environment.
In
this
study,
we
successfully
synthesized
highly
valuable
1,2-bis(boronic)
esters
featuring
nonadjacent
1,3-stereocenters.
Notably,
reaction
selectively
produces
migratory
coupling
products
rather
than
alternative
deborylative
allylation
or
direct
byproducts.
This
approach
introduces
new
activation
mode
for
selective
transformations
gem-diborylmethane
asymmetric
catalysis.
Additionally,
found
that
other
gem-diborylalkanes,
previously
challenging
steric
hindrance,
also
participated
reaction.
incorporation
1,2-bis(boryl)alkenes
facilitated
diversification
alkenyl
two
boron
moieties
our
target
compounds,
thereby
enabling
access
broad
array
versatile
molecules.
DFT
calculations
were
performed
elucidate
mechanism
shed
light
on
factors
responsible
observed
excellent
enantioselectivity
diastereoselectivity.
These
determined
arise
ligand-substrate
repulsions
syn-addition
transition
state.
Organic Process Research & Development,
Journal Year:
2024,
Volume and Issue:
28(4), P. 949 - 977
Published: April 8, 2024
P-Chiral
phosphorus
ligands
received
little
attention
in
organic
chemistry
until
Knowles
made
his
landmark
contribution
asymmetric
hydrogenation
by
developing
the
P-chiral
CAMP
and
DIPAMP.
The
development
of
accelerated
end
last
century
with
advent
some
highly
efficient
renowned
for
hydrogenation,
including
BisP*,
TangPhos,
QuinoxP*,
DuanPhos,
et
al.
However,
most
reported
were
air-sensitive,
difficult
to
make,
or
lacked
structural
modularity,
hampering
their
availability
applicability.
sterically
electronically
tunable
is
particularly
desirable.
Over
past
decade,
a
family
hindered,
electron-rich,
structurally
tunable,
air-stable
dihydrobenzooxaphosphole
emerged
that
proved
be
versatile
various
transformations.
5
years
witnessed
an
increasing
number
studies
related
these
discovery
unprecedented
catalytic
properties
This
review
highlights
unique
catalysis
applications
synthesis
natural
products
therapeutic
agents.
Chemical Science,
Journal Year:
2024,
Volume and Issue:
15(26), P. 10135 - 10145
Published: Jan. 1, 2024
A
stereodivergent
synthesis
of
chiral
ζ-hydroxy
amino
esters
containing
1,6-stereocenters
and
a
unique
β,γ-unsaturation
was
developed
through
asymmetric
Cu/Ru
relay
catalysis
to
conduct
the
borrowing
hydrogenation/1,6-Michael
addition
protocol.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(12), P. 2349 - 2353
Published: March 15, 2024
Enantioselective
construction
of
all-carbon
quaternary
centers
has
been
achieved
via
the
palladium-catalyzed
highly
enantioselective
allenylation
oxindoles
with
2,3-allenylic
carbonates
to
afford
a
variety
optically
active
allene
products,
which
contain
oxindole
units
different
functional
groups,
in
high
ee.
The
corresponding
synthetic
applications
have
also
demonstrated.