ACS Central Science,
Год журнала:
2024,
Номер
11(1), С. 36 - 45
Опубликована: Авг. 16, 2024
Multicomponent
reactions
(MCRs),
highly
sought-after
methods
to
produce
atom-,
step-,
and
energy-economic
organic
syntheses,
have
been
developed
extensively.
However,
catalytic
asymmetric
MCRs,
especially
those
involving
radical
species,
remain
largely
unexplored
owing
the
difficulty
in
stereoselectively
regulating
extraordinarily
high
reactivity
of
open-shell
species.
Herein,
we
report
a
conceptually
novel
three-component
cascade
reaction
readily
accessible
glycine
esters,
α-bromo
carbonyl
compounds
2-vinylcyclopropyl
ketones
via
synergistic
photoredox/Brønsted
acid
catalysis,
which
three
sequential
C–C
(σ/π/σ)
bond-forming
events
occurred
through
addition/ring-opening/radical–radical
coupling
protocol,
affording
an
array
valuable
enantioenriched
unnatural
α-amino
derivatives
bearing
two
contiguous
stereogenic
centers
alkene
moiety
moderate
good
yield
with
diastereoselectivity,
excellent
enantioselectivity
E-dominated
geometry
under
mild
conditions.
The
relay
process,
unique
proton-coupled
electron
transfer
(PCET)-promoted
radical–radical
coupling,
is
supported
by
mechanistic
investigations
quantum
mechanics
calculations
should
garner
broad
interest
further
inspire
development
multicomponent
reactions.
ACS Catalysis,
Год журнала:
2024,
Номер
14(6), С. 3812 - 3844
Опубликована: Фев. 23, 2024
Chiral
skeletons
with
multiple
stereogenic
centers
widely
reside
in
nature
and
drugs,
their
relative
absolute
configuration
often
determine
physiological
or
pharmacological
properties.
Stereodivergent
synthesis
of
chiral
molecules
is
not
only
great
significance,
but
also
highly
challenging
since
the
formation
one
diastereomers
inherently
preferred
most
asymmetric
reactions.
dual
catalysis,
introduced
2013
by
Carreira
group,
perfectly
catered
to
all
requirements
for
full
stereoselectivity
control
given
reactions
two
catalysts
are
utilized
a
synergistic
way
act
independently,
has
now
been
arguably
efficient
strategy
realize
stereodivergent
synthesis.
This
comprehensive
review
presents
an
overview
development
enabled
catalysis
past
ten
years,
providing
readers
fundamental
attributes
as
well
ability,
scope,
mechanism,
limitations
this
strategy.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(13), С. 9241 - 9251
Опубликована: Март 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
Nature Communications,
Год журнала:
2023,
Номер
14(1)
Опубликована: Май 22, 2023
We
herein
describe
an
asymmetric
α-allylic
allenylation
of
β-ketocarbonyls
and
aldehydes
with
1,3-enynes.
A
synergistic
chiral
primary
amine/Pd
catalyst
was
identified
to
facilitate
the
utilization
1,3-enynes
as
atom-economic
achiral
allene
precursors.
The
catalysis
enables
construction
all-carbon
quaternary
centers-tethered
allenes
bearing
non-adjacent
1,3-axial
central
stereogenic
centers
in
high
level
diastereo-
enantio-selectivity.
By
switching
configurations
ligands
aminocatalysts,
diastereodivergence
can
be
achieved
any
four
diastereoisomers
accessed
enantio-
selectivity.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(5), С. 3427 - 3437
Опубликована: Янв. 20, 2024
Despite
half
a
century's
advance
in
the
field
of
transition-metal-catalyzed
asymmetric
alkene
hydrogenation,
enantioselective
hydrogenation
purely
alkyl-substituted
1,1-dialkylethenes
has
remained
an
unmet
challenge.
Herein,
we
describe
chiral
PCNOx-pincer
iridium
complex
for
transfer
this
class
with
ethanol,
furnishing
all-alkyl-substituted
tertiary
stereocenters.
High
levels
enantioselectivity
can
be
achieved
reactions
substrates
secondary/primary
and
primary/primary
alkyl
combinations.
The
catalyst
is
further
applied
to
redox
isomerization
disubstituted
alkenols,
producing
stereocenter
remote
resulting
carbonyl
group.
Mechanistic
studies
reveal
dihydride
species,
(PCNOx)Ir(H)2,
as
catalytically
active
intermediate,
which
decay
dimeric
species
(κ3-PCNOx)IrH(μ-H)2IrH(κ2-PCNOx)
via
ligand-remetalation
pathway.
deactivation
under
conditions
H2
much
faster
than
that
EtOH,
explains
why
(PCNOx)Ir
effective
but
ineffective
hydrogenation.
suppression
di-to-trisubstituted
by
regioselective
1,2-insertion
partly
responsible
success
system,
underscoring
critical
role
played
pincer
ligand
1,1-dialkylethenes.
Moreover,
computational
elucidate
significant
influence
London
dispersion
interaction
between
substrate
on
control,
illustrated
complete
reversal
stereochemistry
through
cyclohexyl-to-cyclopropyl
group
substitution
substrates.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(23)
Опубликована: Фев. 27, 2024
A
novel
enantioselective
Tsuji-Trost-type
cross
coupling
reaction
between
gem-difluorinated
cyclopropanes
and
N-unprotected
amino
acid
esters
enabled
by
synergistic
Pd/Ni/chiral
aldehyde
catalysis
is
presented
herein.
This
transformation
streamlined
the
diversity-oriented
synthesis
(DOS)
of
optically
active
α-quaternary
α-amino
bearing
a
linear
2-fluoroallylic
motif,
which
served
as
an
appealing
platform
for
construction
other
valuable
enantioenriched
compounds.
The
key
intermediates
were
confirmed
HRMS
detection,
while
DFT
calculations
revealed
that
excellent
enantioselectivity
was
attributed
to
stabilizing
non-covalent
interactions
Pd(II)-π-fluoroallyl
species
Ni(II)-Schiff
base
complex.
JACS Au,
Год журнала:
2023,
Номер
3(10), С. 2612 - 2630
Опубликована: Сен. 26, 2023
Alongside
enantioselective
catalysis,
synthetic
chemists
are
often
confronted
by
the
challenge
of
achieving
catalyst
control
over
relative
configuration
to
stereodivergently
access
desired
diastereomers.
Typically,
these
approaches
iteratively
or
simultaneously
multiple
stereogenic
units
for
which
dual
catalytic
methods
comprising
sequential,
relay,
and
synergistic
catalysis
emerged
as
particularly
efficient
strategies.
In
this
Perspective,
benefits
challenges
catalyst-controlled
diastereodivergence
in
construction
carbon
stereocenters
discussed
on
basis
illustrative
examples.
The
concepts
then
transferred
diastereodivergent
atropisomeric
systems
with
twofold
higher-order
stereogenicity
well
E-
Z-configured
alkenes.
Chemical Science,
Год журнала:
2023,
Номер
14(15), С. 4134 - 4142
Опубликована: Янв. 1, 2023
Highly
selective
assembly
of
2,3-fused
indolizines
was
achieved
via
a
cascade
allylation/Friedel–Crafts
type
reaction
with
Cu/Ir
catalysis.
This
protocol
furnishes
stereodivergent
synthesis
chiral
bearing
three
stereogenic
centers
excellent
results.
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
15(22), С. 8280 - 8294
Опубликована: Янв. 1, 2024
The
synthesis
of
enantiomerically
pure
compounds
is
a
pivotal
subject
in
the
field
chemistry,
with
enantioselective
catalysis
currently
standing
as
primary
approach
for
delivering
specific
enantiomers.
Among
these
strategies,
Cu-catalyzed
asymmetric
allylic
substitution
(AAS)
significant
and
irreplaceable,
especially
when
it
comes
to
use
non-stabilized
nucleophiles
(pK
>
25).
Although
AAS
prochiral
substrates
has
also
been
widely
developed,
methodologies
involving
racemic/meso
are
highly
desirable,
undergo
dynamic
processes
give
single
enantiomer
products.
Inspired
by
pioneering
work
Alexakis,
Feringa
Gennari
groups,
continuously
employed
deracemization
desymmetrization
enriched
In
this
review,
we
mainly
focus
on
developments
over
past
two
decades,
providing
an
explicit
outline
ligands
employed,
scope
nucleophiles,
underlying
their
practical
applications.