Palladium(0) π-Lewis Base Catalysis: Concept and Development
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(10), С. 6422 - 6437
Опубликована: Март 1, 2024
The
development
of
a
new
catalytic
strategy
plays
vital
role
in
modern
organic
chemistry
since
it
permits
bond
formation
an
unprecedented
and
more
efficient
manner.
Although
the
application
preformed
metal
complexes
as
π-base-activated
reagents
have
enabled
diverse
transformations
elegantly,
concept
by
directly
utilizing
transition
metals
π-Lewis
base
catalysts
remain
underdeveloped,
especially
field
asymmetric
catalysis.
Here,
we
outline
our
perspective
on
discovery
palladium(0)
catalyst,
which
is
capable
increasing
highest
occupied
molecular
orbital
(HOMO)
energy
both
electron-neutral
electron-deficient
1,3-dienes
1,3-enynes
upon
flexible
η2-complexes
formed
situ
resultant
π-backdonation.
Thus,
fruitful
carbon–carbon-forming
reactions
with
electrophiles
can
be
achieved
enantioselectively
vinylogous
addition
pattern,
conceptually
different
from
classical
oxidative
cyclization
mechanism.
Emphasis
will
given
to
mechanism
elucidation,
features,
reaction
design
together
further
this
emerging
field.
Язык: Английский
Enantioselective Cross-[4 + 2]-Cycloaddition/Decarboxylation of 2-Pyrones by Cooperative Catalysis of the Pd(0)/NHC Complex and Chiral Phosphoric Acid
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(10), С. 6936 - 6946
Опубликована: Фев. 28, 2024
Here,
we
describe
a
cooperative
Pd(0)/chiral
phosphoric
acid
catalytic
system
that
allows
us
to
realize
the
first
chemo-,
regio-,
and
enantioselective
sequential
cross-[4
+
2]-cycloaddition/decarboxylation
reaction
between
2-pyrones
unactivated
acyclic
1,3-dienes.
The
key
success
of
this
transformation
is
utilization
an
achiral
N-heterocyclic
carbene
(NHC)
as
ligand
newly
developed
chiral
cocatalyst.
Experimental
investigations
computational
studies
support
idea
Pd(0)/NHC
complex
acts
π-Lewis
base
increase
nucleophilicity
1,3-dienes
via
η2
coordination,
while
simultaneously
increases
electrophilicity
by
hydrogen
bonding.
By
synergistic
catalysis,
2]-cycloaddition
decarboxylation
proceeds
efficiently,
enabling
preparation
wide
range
vinyl-substituted
1,3-cyclohexadienes
in
good
yields
enantioselectivities.
synthetic
utility
demonstrated
transformations
product
various
valuable
six-membered
carbocycles.
Язык: Английский
Carbene-Catalyzed Enantioselective Petasis-Like Alkenylation
ACS Catalysis,
Год журнала:
2024,
Номер
14(3), С. 2003 - 2013
Опубликована: Янв. 23, 2024
The
N-heterocyclic
carbene
(NHC)-catalyzed
enantioselective
Petasis-like
alkenylation
of
o-hydroxycinnamaldehydes
or
hydroxyl-tethered
α,β-unsaturated
aldehydes
with
styryl,
dienyl,
trienyl
boronic
acids
is
disclosed.
This
method
involves
the
addition
π-system-containing
to
NHC-bounded
acyl
azoliums
and
allows
access
divergent
assembly
β-alkenyl
substituted
dihydrocoumarin
γ-
δ-lactones.
DFT
calculations
suggest
that
an
unprecedented
zwitterionic
intermediate
1,4-
1,5-
migration
alkenyl
groups
play
a
crucial
role
in
reaction.
More
in-depth
studies
orbital
noncovalent
interaction
analysis
provide
more
detailed
explanations
for
pathways
stereoselectivity
control.
Язык: Английский
Palladium-Catalyzed Divergent Synthesis from o-Sulfonamido Trifluoroacetophenones and 2-En-4-ynyl Carbonates
Organic Letters,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 15, 2025
Here
we
present
a
palladium-catalyzed
divergent
transformative
reaction
between
o-sulfonamido
trifluoroacetophenones
and
2-en-4-ynyl
carbonates.
A
spectrum
of
enantioenriched
2,5-dihydrofuran-fused
tetrahydroquinolines
bearing
either
(Z)-
or
(E)-exocyclic
double
bond
are
constructed
with
moderate
to
high
enantioselectivity
from
5-aryl-substituted
carbonates
by
tuning
palladium
sources,
while
analogous
2,3-dihydrofuran-fused
products
furnished
using
5-alkyl-substituted
ones.
Язык: Английский
Enantioselective Construction of Polycyclic Chromanes through Organocatalytic Sequential Quintuple Reaction via One‐Pot Step‐Wise Procedure
Chinese Journal of Chemistry,
Год журнала:
2024,
Номер
42(18), С. 2197 - 2202
Опубликована: Май 14, 2024
Comprehensive
Summary
An
efficient
and
highly
stereoselective
synthetic
method
to
access
polycyclic
chromanes
has
been
achieved
through
organocatalyzed
one‐pot
step‐wise
reactions
involving
2‐hydroxycinnamaldehydes,
2‐aminochalcones,
malononitrile
as
substrates.
The
underwent
a
quintuple
process
by
aza‐Michael/Michael/Knoevenagel/oxa‐Michael/aldol‐type
reaction
in
sequence
give
products
bearing
3
new
generated
rings
5
chiral
centers
moderate
quantitative
yields
with
excellent
stereoselectivities.
A
novel
retro‐reaction
mechanism
was
discovered
the
transformations
of
products.
Язык: Английский
Pd-Catalyzed Asymmetric Allylic Substitution Cascade via Desymmetrization for the Construction of Chiral Polyheterocycles
Pharmaceutical Fronts,
Год журнала:
2024,
Номер
06(03), С. e237 - e251
Опубликована: Авг. 6, 2024
Chiral
polyheterocycles
represent
an
important
class
of
compounds
because
their
prevalence
in
bioactive
natural
products
and
chiral
drugs.
Pd-catalyzed
allylic
substitution
is
a
powerful
synthetic
tool
for
forming
C–C
C–X
bonds
(X
=
N,
O,
S,
etc.).
Naturally,
asymmetric
cascade
reactions
that
utilize
are
undoubtedly
efficient
pathways
to
construct
heterocycles.
In
this
article,
we
reviewed
the
via
desymmetrization
meso-diol
diesters
cycloolefins,
construction
derivatives.
Язык: Английский