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.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(36)
Published: May 23, 2024
Bis(alkenyl)boronates
react
with
optically
active
Ir(π-allyl)
species
in
a
process
that
involves
allylation
of
the
more
substituted
olefin
and
1,2-metalate
shift
less
olefin.
The
method
constructs
valuable
enantioenriched
tertiary
allylic
boronic
esters
high
chemoselectivity,
enantioselectivity
diastereoselectivity.
Allylic
functionalization
reactions
transform
1,3-stereodiad
to
1,5-
1,6-stereochemical
relationships.
Chemical Science,
Journal Year:
2023,
Volume and Issue:
14(39), P. 10812 - 10823
Published: Jan. 1, 2023
A
class
of
prochiral
allenylic
di-electrophiles
have
been
introduced
for
the
first
time
as
three-atom
synthons
in
cycloadditions,
and
a
new
type
[4+3]
cycloaddition
involving
transition
metal-catalyzed
enantioselective
sequential
substitution
has
successfully
developed,
enabling
challenging
seven-membered
exocyclic
axially
chiral
allenes
to
be
accessed
good
yields
with
enantioselectivity.
Through
addition
catalytic
amount
ortho-aminoanilines
or
ortho-aminophenols,
racemization
products
is
effectively
suppressed.
Mechanistic
studies
reveal
that
elusive
Pd-catalyzed
intramolecular
rather
than
intermolecular
enantio-determining
step
this
cycloaddition.
By
tuning
ligands,
desymmetric
leading
linear
tri-substituted
tandem
substitution/β-vinylic
hydrogen
elimination
(formal
enynylation)
multi-functionalized
1,3-enynes
achieved
chemodivergently.
Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: Dec. 8, 2023
Abstract
The
stereocontrolled
allylic
alkylation
of
carbonyl
compounds
with
the
goal
producing
full
range
stereoisomers
presents
an
effective
approach
for
increasing
productivity
collective
natural
product
synthesis
and
creation
chiral
molecule
libraries
drug
exploration.
simultaneous
control
regio-,
diastereo-,
enantioselectivity
poses
a
significant
synthetic
challenge
in
contemporary
organic
synthesis.
Herein,
we
describe
catalytic
stereodivergent
α-allylation
protocol
applicable
to
both
aliphatic
aromatic
2-acylimidazoles,
thereby
providing
practical
blueprint
divergent
important
building
blocks.
Each
six
isomeric
α-allylated
can
be
readily
obtained
remarkable
yields
exceptional
stereoselectivities,
by
judiciously
selecting
appropriate
leaving
group
permutations
enantiomers
adapted
from
nickel
iridium
catalysts.
versatility
this
asymmetric
has
been
successfully
utilized
enantioselective
(
R
)-arundic
acid
S
,
)-cinamomumolide,
as
well
total
tapentadol.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(45)
Published: July 11, 2024
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-2H-1,4-benzoxazines
high
efficiency
selectivity.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(32), P. 6006 - 6011
Published: Aug. 1, 2023
We
report
an
enantio-
and
diastereodivergent
synthesis
of
enantioenriched
fluorenes
bearing
bis-1,3-nonadjacent
stereocenters
with
broad
substrate
scope
high
enantioselectivity
(up
to
99%
ee)
under
low
catalyst
loading
(0.1
mol
%).
The
key
the
success
this
method
is
pseudo-diastereodivergent
desymmetrization
stereoisomers
meso-epoxides
enabled
by
same
organocatalyst.
Furthermore,
some
chiral
obtained
exhibit
fluorescence
quantum
yields
76.6%),
as
evidenced
photophysical
properties
studies.
Organic & Biomolecular Chemistry,
Journal Year:
2023,
Volume and Issue:
21(42), P. 8516 - 8520
Published: Jan. 1, 2023
An
enantioselective
synthesis
of
substituted
chiral
allenes
with
nonadjacent
axial
and
two
central
centers
is
reported,
using
a
combination
retro-oxa-Michael
addition
palladium-catalyzed
asymmetric
allenylic
alkylation.
Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(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.
Angewandte Chemie,
Journal Year:
2023,
Volume and Issue:
136(5)
Published: Dec. 15, 2023
Abstract
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
‐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.
Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(36)
Published: July 9, 2024
Abstract
Bis(alkenyl)boronates
react
with
optically
active
Ir(
π
‐allyl)
species
in
a
process
that
involves
allylation
of
the
more
substituted
olefin
and
1,2‐metalate
shift
less
olefin.
The
method
constructs
valuable
enantioenriched
tertiary
allylic
boronic
esters
high
chemoselectivity,
enantioselectivity
diastereoselectivity.
Allylic
functionalization
reactions
transform
1,3‐stereodiad
to
1,5‐
1,6‐stereochemical
relationships.
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.
