Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
62(2)
Published: Nov. 16, 2022
Abstract
Synergistic
catalysis
has
emerged
as
one
of
the
most
powerful
tools
for
stereodivergent
formation
Csp
3
−Csp
bonds
bearing
vicinal
stereocenters.
Despite
many
successes
that
have
been
achieved
in
this
field,
coupling
reactions
involving
stabilized
nucleophiles
remain
challenging
because
competing
single‐catalysis
pathway.
Herein,
we
report
a
synergistic
palladium/phase‐transfer
catalyst
system
enables
diastereodivergent
1,3‐dienes
with
nucleophile
oxindoles.
Both
syn
and
anti
products,
quaternary
tertiary
stereocenters,
could
be
selectively
produced
good
yields
high
enantio‐
diastereoselectivities.
Non‐covalent
activation
via
chiral
ion
pair
biphasic
is
crucial
success
factor
achieving
diastereodivergence.
Chemical Reviews,
Journal Year:
2021,
Volume and Issue:
122(2), P. 2650 - 2694
Published: Aug. 27, 2021
Geometrical
E
→
Z
alkene
isomerization
is
intimately
entwined
in
the
historical
fabric
of
organic
photochemistry
and
enjoying
a
renaissance
(Roth
et
al.
Angew.
Chem.,
Int.
Ed.
Engl.
1989
28,
1193–1207).
This
consequence
fundamental
stereochemical
importance
Z-alkenes,
juxtaposed
with
frustrations
thermal
reactivity
that
are
rooted
microscopic
reversibility.
Accessing
excited
state
paradigms
allow
this
latter
obstacle
to
be
circumnavigated
by
exploiting
subtle
differences
photophysical
behavior
substrate
product
chromophores:
provides
molecular
basis
for
directionality.
While
direct
irradiation
operationally
simple,
photosensitization
via
selective
energy
transfer
enables
augmentation
repertoire
include
substrates
not
directly
photons.
Through
sustained
innovation,
an
impressive
portfolio
tailored
small
molecule
catalysts
range
triplet
energies
now
widely
available
facilitate
contra-thermodynamic
thermo-neutral
reactions
generate
Z-alkene
fragments.
review
intended
serve
as
practical
guide
covering
geometric
alkenes
enabled
catalysis
from
2000
2020,
logical
sequel
excellent
treatment
Dugave
Demange
(Chem.
Rev.
2003
103,
2475–2532).
The
mechanistic
foundations
underpinning
selectivity
discussed
together
induction
models
rationales
explain
counterintuitive
directionality
these
processes
which
very
distinguish
product.
Implications
subsequent
stereospecific
transformations,
application
total
synthesis,
regioselective
polyene
isomerization,
spatiotemporal
control
pre-existing
configuration
broader
sense
discussed.
Journal of the American Chemical Society,
Journal Year:
2021,
Volume and Issue:
143(19), P. 7285 - 7291
Published: May 10, 2021
Herein
we
describe
a
protocol
for
the
unprecedented
stereodivergent
synthesis
of
tertiary
fluoride-tethered
allenes
bearing
stereogenic
center
and
axis
via
Cu/Pd
synergistic
catalysis.
A
broad
scope
conjugated
enynes
are
coupled
with
various
α-fluoroesters
in
high
yields
diastereoselectivities
generally
>99%
ee.
In
addition,
four
stereoisomers
allene
products
ensure
precise
access
to
corresponding
fluorinated
hydrofurans
novel
axial-to-central
chirality
transfer
process.
Journal of the American Chemical Society,
Journal Year:
2021,
Volume and Issue:
143(32), P. 12622 - 12632
Published: Aug. 5, 2021
In
contrast
to
the
widely
explored
methods
for
asymmetric
synthesis
of
molecules
bearing
a
single
stereocenter
or
adjacent
stereocenters,
concurrent
construction
1,3-stereogenic
centers
in
an
enantio-
and
diastereoselective
manner
remains
challenge,
especially
acyclic
systems.
Herein,
we
report
diastereodivergent
1,3-nonadjacent
stereocenters
allenyl
axial
central
chirality
through
synergistic
Pd/Cu-catalyzed
dynamic
kinetic
allenylation
with
racemic
allenylic
esters.
The
protocol
is
suitable
wide
range
substrates
including
challenging
esters
less
sterically
bulky
substituents
provided
chiral
products
high
levels
diastereoselectivities
(up
>20:1
dr
>99%
ee).
Furthermore,
several
representative
transformations
involving
axial-to-central
transfer
were
conducted,
affording
useful
structural
motifs
containing
nonadjacent
manner.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(45)
Published: Aug. 2, 2022
Abstract
Bimetallic
catalysis
has
emerged
as
an
efficient
strategy
for
the
development
of
new
chemical
reactions.
Importantly,
this
also
provides
a
simple
and
powerful
platform
stereodivergent
synthesis,
whereby
all
possible
stereoisomers
products
bearing
two
stereocenters
can
be
easily
prepared
from
same
set
starting
materials.
In
Minireview,
allylic
substitution,
propargylic
hydrofunctionalization,
annulation
based
on
bimetallic
been
summarized.
It
is
expected
that
more
catalytic
systems
will
developed
applied
synthesis
valuable
molecules.
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
144(4), P. 1971 - 1985
Published: Jan. 20, 2022
Comprehensive
computational
studies
were
carried
out
to
explore
the
mechanisms
of
enantioselective
Cu/Pd
and
stereodivergent
Cu/Ir
dual-catalytic
syntheses
α,α-disubstituted
α-amino
acids
(α-AAs).
A
chiral
copper
azomethine
ylide
undergoes
facile
α-allylation
with
racemic
π-allylpalladium
species
or
stereopure
π-allyliridium
complex
stereoconvergently
stereodivergently
furnish
single/double
stereocenters,
respectively.
Stereoselectivity
at
α-center
is
controlled
by
facial
selectivity
respect
prochiral
nucleophile.
Despite
apparently
similar
transition-state
assemblies,
models
distortion/interaction
analyses
disclose
versatile
modes
stereoinduction
wherein
can
face-selectively
intercept
metal−π-allyl
intermediates
utilizing
attractive
dispersion
interactions
and/or
sterically
caused
distortions.
Generation
β-stereocenter
in
system
relies
on
a
stereospecifically
generated
allyliridium
electronically
branched-to-linear
selectivity,
while
dual
yields
linear
monochiral
product
due
steric
factors
π–π
stacking
interactions.
The
demonstrate
molecular
level
how
ligand-encoded
information
transferred
α-/β-sites
resulting
α-AAs
mode
regio-/stereoselection
altered
differences
transition-metal-stabilized
coupling
partners.
To
facilitate
stereoselective
catalysis,
suite
analytical
tools
extract
controlling
for
asymmetric
induction
demonstrated.
Nature Communications,
Journal Year:
2022,
Volume and Issue:
13(1)
Published: Sept. 17, 2022
The
selective
oxidation
of
glycerol
to
glyceric
acid,
an
important
value-added
reaction
from
polyols,
is
a
typical
cascade
catalytic
process.
It
still
great
challenge
simultaneously
achieve
high
activity
and
acid
selectivity,
suffering
either
deep
C-C
cleavage
or
poor
efficiency
glyceraldehyde
acid.
Herein,
this
work,
inspired
by
nature,
proposes
synergistic
catalysis
strategy
atomic
low-coordinated
cluster
Pt
on
well-defined
Cu-CuZrOx,
which
involves
enhanced
C-H
activation
Pt1
O-H
Ptn
in
the
glyceraldehyde,
for
C=O
followed
insertion
tandem
process
revealed
be
essential
(90.0±0.1%)
selectivity
(80.2±0.2%).
Nature Communications,
Journal Year:
2022,
Volume and Issue:
13(1)
Published: Jan. 25, 2022
Abstract
A
continuous
flow
cascade
of
multi-step
catalytic
reactions
is
a
cutting-edge
concept
to
revolutionize
stepwise
synthesis
yet
still
challenging
in
practical
applications.
Herein,
method
for
one-pot
catalysis
developed
by
combining
Pickering
emulsions
with
flow.
Our
involves
co-localization
different
catalytically
active
sub-compartments
within
droplets
emulsion
yielding
cell-like
microreactors,
which
can
be
packed
column
reactor
catalysis.
As
exemplified
two
chemo-enzymatic
the
chiral
cyanohydrins
and
ester,
5
−
420
fold
enhancement
efficiency
as
high
99%
enantioselectivity
were
obtained
even
over
period
80
240
h.
The
compartmentalization
effect
enriching-reactant
properties
arising
from
biomimetic
microreactor
are
theoretically
experimentally
identified
key
factors
boosting
regulating
kinetics
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(36)
Published: June 28, 2022
An
unprecedented
hydroalkylation
of
racemic
allylic
alcohols
and
ketimine
esters
enabled
by
Cu/Ru
relay
catalysis
has
been
developed
via
merging
the
ruthenium-catalyzed
asymmetric
borrowing-hydrogen
reaction
with
a
copper-catalyzed
Michael
addition
in
one-pot
procedure.
The
current
method
enables
efficient
preparation
highly
functionalized
δ-hydroxyesters
bearing
1,4-nonadjacent
stereocenters
good
yields
high
levels
diastereoselectivity
excellent
enantioselectivity
under
mild
conditions.
full
complement
four
stereoisomers
products
could
be
readily
accessed
orthogonal
permutations
two
chiral
metal
catalysts.
work
highlights
power
for
stereodivergent
construction
that
were
otherwise
inaccessible.