Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(46)
Published: Sept. 26, 2022
We
describe
cooperative
bimetallic
catalysis
that
enables
regio-/stereodivergent
asymmetric
α-allylations
of
aldimine
esters.
By
employing
Et3
B
as
the
key
activator,
racemic
allylic
alcohols
can
be
directly
ionized
to
form
Pd
or
Ir-π-allyl
species
in
presence
achiral
chiral
Ir
complexes,
respectively.
The
less
more
substituted
termini
metal-π-allyl
are
amenable
nucleophilic
attack
by
Cu-azomethine
ylide,
formation
which
is
simultaneously
facilitated
B,
affording
α-quaternary
α-amino
acids
with
high
regioselectivity
and
excellent
stereoselectivity.
use
readily
available
electrophilic
precursors
represents
an
improvement
from
environmental
atom/step
economy
perspective.
Computational
mechanistic
studies
reveal
crucial
role
additive
origins
stereo-
regioselectivities
analyzing
steric
effects,
dispersion
interactions,
frontier
orbital
population.
ACS Catalysis,
Journal Year:
2021,
Volume and Issue:
11(7), P. 3891 - 3915
Published: March 15, 2021
Multicatalysis
is
an
emerging
field
targeting
the
development
of
efficient
catalytic
transformations
to
quickly
convert
relatively
simple
starting
materials
into
more
complex
value-added
products.
Within
multicatalytic
processes
either
multiple
catalysts
execute
single
reactions
or
precise
sequences
occur
in
a
"one-pot"
fashion.
Attractively,
protocols
not
only
enable
that
are
inaccessible
through
classic
approaches
but
also
able
significantly
reduce
time,
waste,
and
cost
synthetic
processes,
making
organic
synthesis
resources
efficient.
In
this
Perspective
article,
we
review
different
strategies
multicatalysis
bring
distinct
challenges
opportunities.
We
divide
overarching
three
main
categories:
cooperative,
domino,
relay
catalysis.
Each
category
described
along
with
representative
examples
highlight
its
features.
Special
emphasis
dedicated
catalysis,
which
further
discussed
subcategories.
Lastly,
provide
analysis
systems
incorporate
higher
levels
complexity
underscore
potential
systems.
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.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
60(47), P. 24941 - 24949
Published: Sept. 17, 2021
The
development
of
efficient
and
straightforward
methods
for
obtaining
all
optically
active
isomers
structurally
rigid
spirocycles
from
readily
available
starting
materials
is
great
value
in
drug
discovery
chiral
ligand
development.
However,
the
stereodivergent
synthesis
bearing
multiple
stereocenters
remains
an
unsolved
challenge
owing
to
steric
hindrance
ring
strain.
Herein,
we
report
enantio-
diastereodivergent
through
dual-metal-catalyzed
[3+2]
annulation
oxy
π-allyl
metallic
dipoles
with
less
commonly
employed
nucleophilic
(imino
esters).
A
series
spiro
compounds
a
pyrroline
olefin
were
easily
synthesized
manner
(up
19:1
dr,
>99
%
ee),
which
showed
promise
as
new
type
N-olefin
ligand.
Preliminary
mechanistic
studies
also
carried
out
understand
process
this
bimetallic
catalysis.
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
144(16), P. 7015 - 7029
Published: April 12, 2022
Compounds
rich
in
sp3-hybridized
carbons
are
desirable
drug
discovery.
Nickel-catalyzed
hydrocarbonation
of
alkenes
is
a
potentially
efficient
method
to
synthesize
these
compounds.
By
using
abundant,
readily
available,
and
stable
as
pro-nucleophiles,
reactions
can
have
broad
scope
high
functional
group
tolerance.
However,
this
methodology
still
an
early
stage
development,
the
first
examples
were
reported
only
2016.
Herein,
we
summarize
progress
emerging
field,
with
emphasis
on
enantioselective
reactions.
We
highlight
major
developments,
critically
discuss
wide
range
possible
mechanisms,
offer
our
perspective
state
challenges
field.
hope
Perspective
will
stimulate
future
works
area,
making
widely
applicable
organic
synthesis.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
60(47), P. 24930 - 24940
Published: Oct. 11, 2021
By
virtue
of
a
fundamentally
new
reaction
model
azomethine
ylide
serving
as
two-atom
synthon,
we
present
the
first
example
stereodivergent
preparation
γ-butyrolactones
via
synergistic
Cu/Ir-catalyzed
asymmetric
cascade
allylation/lactonization,
and
all
four
stereoisomers
bearing
two
vicinal
stereocenters
are
accessible
with
excellent
diastereoselective
enantioselective
control.
The
chiral
IrIII
-π-allyl
intermediate
was
separated
characterized
to
understand
origin
regio-
stereoselectivity
initial
C-C
bond
formation
process.
Control
experiments
shed
some
light
on
catalyst/substrate
catalyst/catalyst
interactions
in
this
dual
catalytic
system
rationalize
related
kinetic/dynamic
kinetic
resolution
process
different
catalyst
combinations.
enantioenriched
γ-butyrolactone
products
were
converted
into
an
array
structurally
complex
molecules
organocatalysts
that
otherwise
inaccessible.
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.
Chemical Society Reviews,
Journal Year:
2023,
Volume and Issue:
52(21), P. 7602 - 7664
Published: Jan. 1, 2023
Carbon
nitrides,
with
feasibility
of
tailored
band
gap
via
suitable
nanoarchitectonics,
are
deemed
as
best
catalysts
amongst
existing
materials,
especially
for
HER,
OWS,
COR,
NRR,
water
oxidation,
pollutant
removal,
and
organocatalysis.