Chemical Science,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 4, 2024
A
stereodivergent,
W-catalyzed
alkene
isomerization
is
reported,
leading
to
either
E
-
or
Z
-β,γ-unsaturated
carbonyl
compounds
based
on
the
ligand
environment
around
metal.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(12), С. 8372 - 8380
Опубликована: Март 18, 2024
Here
we
present
a
highly
enantioselective
[2π
+
2σ]
photocycloaddition
of
bicyclo[1.1.0]butanes
(BCBs).
The
reaction
uses
variety
vinylazaarenes
as
partners
and
is
catalyzed
by
polycyclic
aromatic
hydrocarbon
(PAH)-containing
chiral
phosphoric
acid
bifunctional
photosensitizer.
A
wide
array
pharmaceutically
important
bicyclo[2.1.1]hexane
(BCH)
derivatives
have
been
synthesized
with
high
yields,
enantioselectivity,
diastereoselectivity.
In
addition
to
the
diverse
1-ketocarbonyl-3-substituted
BCBs,
α/β-substituted
are
compatible
such
an
unprecedented
photoredox
catalytic
pathway,
resulting
in
successful
assembly
all-carbon
quaternary
stereocenter
or
two
adjacent
tertiary
stereocenters
on
product.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(15), С. 10857 - 10867
Опубликована: Апрель 8, 2024
The
asymmetric
cross-coupling
of
unsaturated
bonds,
hampered
by
their
comparable
polarity
and
reactivity,
as
well
the
scarcity
efficient
catalytic
systems
capable
diastereo-
enantiocontrol,
presents
a
significant
hurdle
in
organic
synthesis.
In
this
study,
we
introduce
highly
adaptable
photochemical
cobalt
catalysis
framework
that
facilitates
chemo-
stereoselective
reductive
cross-couplings
between
common
aldehydes
with
broad
array
carbonyl
iminyl
compounds,
including
N-acylhydrazones,
aryl
ketones,
aldehydes,
α-keto
esters.
Our
methodology
hinges
on
synergistic
mechanism
driven
photoredox-induced
single-electron
reduction
subsequent
radical–radical
coupling,
all
precisely
guided
chiral
catalyst.
Various
optically
enriched
β-amino
alcohols
unsymmetrical
1,2-diol
derivatives
(80
examples)
have
been
synthesized
good
yields
(up
to
90%
yield)
high
stereoselectivities
>20:1
dr,
99%
ee).
Of
particular
note,
approach
accomplishes
unattainable
transformations
disparate
partners
without
reliance
any
external
photosensitizer,
thereby
further
emphasizing
its
versatility
cost-efficiency.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(30)
Опубликована: Апрель 30, 2024
Abstract
Consecutive
photoinduced
electron
transfer
(ConPET)
is
a
powerful
and
atom‐economical
protocol
to
overcome
the
limitations
of
intrinsic
redox
potential
visible
light‐absorbing
photosensitizers,
thereby
considerably
improving
substrate
reaction
types.
Likely
because
such
an
exothermic
single‐electron
(SET)
process
usually
does
not
require
aid
chiral
catalysts,
resulting
in
inevitable
racemic
background
reaction,
notably,
no
enantioselective
manifolds
have
been
reported.
Herein,
we
report
on
viability
cooperative
ConPET
hydrogen‐bonding
catalysis
for
[3+2]
photocycloaddition
cyclopropyl
ketones
with
vinylazaarenes.
In
addition
enabling
first
use
olefins
that
preferentially
interact
this
platform
paves
way
efficient
synthesis
pharmaceutically
synthetically
important
cyclopentyl
functionalized
by
azaarenes
high
yields,
ees
dr.
The
robust
capacity
method
can
be
further
highlighted
low
loading
catalyst
(1.0
mol
%),
good
compatibility
both
2‐azaarene
3‐pyridine‐based
olefins,
successful
concurrent
construction
three
stereocenters
cyclopentane
rings
involving
elusive
but
all‐carbon
quaternary.
Abstract
An
unprecedented
enantioselective
protonation
reaction
enabled
by
photoredox
catalytic
radical
coupling
is
developed.
Under
cooperative
dicynopyrazine‐derived
chromophore
(DPZ)
as
a
photosensitizer
and
chiral
phosphoric
acid
catalyst,
Hantzsch
ester
sacrificial
reductant,
the
transformations
between
α‐substituted
enones
cyanoazaarenes
or
2‐(chloromethyl)azaaren‐1‐iums
can
proceed
tandem
reduction,
coupling,
process
efficiently.
Two
classes
of
pharmaceutically
important
enantioenriched
azaarene
variants,
which
contain
synthetically
versatile
ketone‐substituted
tertiary
carbon
stereocenter
at
β
‐
γ
‐position
azaarenes,
are
synthesized
with
high
yields
ees.
Organic Letters,
Год журнала:
2025,
Номер
27(5), С. 1244 - 1249
Опубликована: Янв. 23, 2025
An
asymmetric
photoredox
catalytic
Minisci-type
reaction
between
α-bromide
amides
and
imine-containing
azaarenes
has
been
successfully
developed.
This
catalyst
system
employs
a
chiral
phosphoric
acid
alongside
3DPAFIPN
as
photosensitizer.
The
produces
diverse
array
of
valuable
amides,
featuring
azaarene-substituted
tertiary
carbon
stereocenters
at
the
β-position,
in
high
yields
(up
to
85%)
good
excellent
enantioselectivities
>99%
enantiomeric
excess
(ee)).
Importantly,
this
work
marks
first
example
radical
addition
simple
utilizing
radicals
functionalized
with
electron-withdrawing
carbonyl
groups,
which
are
conventionally
considered
unfavorable
for
such
transformations,
especially
an
enantioselective
manner.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 29, 2025
Imine-containing
azaarene-based
triarylmethanes
are
vital
molecular
motifs
that
prevalent
in
a
wide
array
of
bioactive
compounds.
Recognizing
the
limitations
current
synthetic
methodologies─marked
by
scarcity
examples
and
difficulties
flexible
functional
group
modulation─we
have
developed
an
efficient
modular
asymmetric
photochemical
strategy
employing
pyridotriazoles
boronic
acids
as
substrates.
Utilizing
novel
chiral
diamine-derived
pyrroles
primary
amines
catalysts,
we
successfully
synthesized
diverse
range
with
high
yields
excellent
enantioselectivities.
This
method
not
only
exhibits
broad
substrate
scope
outstanding
tolerance
but
also
enables
precise
synthesis
deuterated
derivatives
using
inexpensive
D2O
deuterium
source.
Mechanistic
studies
reveal
unusual
1,4-boron
shift
is
critical
step
generating
boronated
enamine
intermediate,
while
shedding
light
on
potential
enantiocontrol
mechanisms
facilitated
catalyst.
Frontiers in Chemistry,
Год журнала:
2024,
Номер
12
Опубликована: Май 9, 2024
Asymmetric
catalysis
stands
at
the
forefront
of
modern
chemistry,
serving
as
a
cornerstone
for
efficient
creation
enantiopure
chiral
molecules
characterized
by
their
high
selectivity.
In
this
review,
we
delve
into
realm
asymmetric
catalytic
reactions,
which
spans
various
methodologies,
each
contributing
to
broader
landscape
enantioselective
synthesis
molecules.
Transition
metals
play
central
role
catalysts
wide
range
transformations
with
ligands
such
phosphines,
N
-heterocyclic
carbenes
(NHCs),
etc.,
facilitating
formation
C-C
and
C-X
bonds,
enabling
precise
control
over
stereochemistry.
Enantioselective
photocatalytic
reactions
leverage
power
light
driving
force
electrocatalysis
has
emerged
sustainable
approach,
being
both
atom-efficient
environmentally
friendly,
while
offering
versatile
toolkit
reductions
oxidations.
Biocatalysis
relies
on
nature’s
most
catalysts,
i.e.,
enzymes,
provide
exquisite
selectivity,
well
tolerance
diverse
functional
groups
under
mild
conditions.
Thus,
enzymatic
optical
resolution,
kinetic
resolution
dynamic
have
revolutionized
production
compounds.
organocatalysis
uses
metal-free
organocatalysts,
consisting
modular
phosphorus,
sulfur
nitrogen
components,
remarkably
transformations.
Additionally,
unlocking
traditionally
unreactive
C-H
bonds
through
selective
functionalization
expanded
arsenal
synthesis,
atom-economical
construction
Incorporating
flow
chemistry
been
transformative,
continuous
systems
reaction
conditions,
enhancing
efficiency
optimization.
Researchers
are
increasingly
adopting
hybrid
approaches
that
combine
multiple
strategies
synergistically
tackle
complex
synthetic
challenges.
This
convergence
holds
great
promise,
propelling
field
forward
in
form.
As
these
methodologies
evolve
complement
one
another,
they
push
boundaries
what
can
be
accomplished
leading
discovery
novel,
highly
may
lead
groundbreaking
applications
across
industries.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Май 29, 2024
Abstract
Photocatalysis
through
energy
transfer
has
been
investigated
for
the
facilitation
of
[4
+
2]
cycloaddition
reactions.
However,
high
reactivity
radical
species
poses
a
challenging
obstacle
to
achieving
enantiocontrol
with
chiral
catalysts,
as
no
enantioselective
examples
have
reported
thus
far.
Here,
we
present
development
catalytic
asymmetric
dearomative
photocycloaddition
involving
anthracene
and
its
derivatives
alkenylazaarenes.
This
accomplishment
is
achieved
by
utilizing
cooperative
photosensitizer
Brønsted
acid
catalysis
platform.
Importantly,
this
process
enables
activation
substrates
from
triplet
DPZ,
thereby
initiating
precise
stereoselective
sequential
transformation.
The
significance
our
work
highlighted
synthesis
diverse
range
pharmaceutical
valuable
cycloadducts
incorporating
attractive
azaarenes,
all
obtained
yields,
ees,
drs.
broad
substrate
scope
further
underscored
successful
construction
all-carbon
quaternary
stereocenters
adjacent
stereocenters.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Июнь 20, 2024
The
synthesis
of
chiral
α-azaheteroaryl
oxiranes
via
enantioselective
catalysis
is
a
formidable
challenge
due
to
the
required
complex
stereoselectivity
and
diverse
N-heterocyclic
structures.
These
compounds
play
crucial
role
in
developing
bioactive
molecules,
where
precise
chirality
significantly
influences
biological
activity.
Here
we
show
that
using
phosphoric
acid
as
catalyst,
our
method
efficiently
addresses
these
challenges.
This
technique
not
only
achieves
high
enantio-
diastereoselectivity
but
also
demonstrates
superior
chemo-
stereocontrol
during
epoxidation
alkenyl
aza-heteroarenes.
Our
approach
leverages
synergistic
blend
electrostatic
hydrogen-bonding
interactions,
enabling
effective
activation
both
substrates
hydrogen
peroxide.
resulting
exhibit
enhanced
diversity
functionality,
aiding
construction
azaaryl
with
contiguous
stereocenters.
Kinetic
density
functional
theory
studies
elucidate
mechanism,
highlighting
acid's
pivotal
this
intricate
process.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 23, 2025
Recent
advancements
in
green
and
sustainable
platforms,
particularly
visible
light-driven
photocatalysis,
have
spurred
significant
progress
radical
chemistry,
enabling
the
efficient
synthesis
of
important
molecules
from
simple
readily
available
feedstocks
under
mild
conditions.
However,
rapid
orbital
flipping
high
reactivity
radicals
pose
substantial
challenges
for
achieving
precise
enantiocontrol
stereocenter
formation
via
coupling.
In
this
study,
we
present
a
generic
strategy
that
modulates
elusive
approach,
facilitating
enantiocontrollable
protonation
through
1,3-boron
migration.
We
successfully
developed
two
previously
photocatalytic
asymmetric
transformations:
de
Mayo
reaction
utilizing
energy
transfer
three-component
reactions
cyanoazaarenes
initiated
by
single-electron
transfer.
Moreover,
incorporation
cost-effective
D2O
as
deuterium
source
enhances
synthetic
pharmaceutical
significance
method,
offering
valuable
tool
future
applications.