Chemistry - A European Journal,
Год журнала:
2020,
Номер
26(66), С. 15052 - 15064
Опубликована: Июль 2, 2020
Over
the
past
decades,
organometallic
complexes
with
precious
elements,
such
as
ruthenium
and
iridium,
are
widely
used
visible-light
photoredox
catalysts.
Recently,
more
based
on
earth-abundant
inexpensive
elements
have
been
sensitizers
in
photochemistry.
Although
photoexcited
state
lifetimes
of
iron
typically
shorter
than
those
traditional
photosensitizers,
utilization
catalysts
photochemistry
has
sprung
up
owing
to
their
abundance,
low
price,
nontoxicity,
novel
properties,
including
exhibiting
ligand
metal
charge
transfer
states.
This
concept
focuses
recent
advances
light-driven
catalysis
organic
transformations,
iron/photoredox
dual
catalysis,
light-induced
generation
active
The
prospect
for
future
this
field
is
also
discussed.
Journal of the American Chemical Society,
Год журнала:
2022,
Номер
144(5), С. 2218 - 2224
Опубликована: Янв. 6, 2022
We
report
a
visible-light-induced
copper-catalyzed
highly
enantioselective
umpolung
allylic
acylation
reaction
with
acylsilanes
as
acyl
anion
equivalents.
Triplet-quenching
experiments
and
DFT
calculations
supported
our
design,
which
is
based
on
copper-to-acyl
metal-to-ligand
charge
transfer
(MLCT)
photoexcitation
that
generates
charge-separated
triplet
state
reactive
intermediate.
According
to
the
calculations,
phosphate
substrate
in
excited
undergoes
novel
molecular
activation
into
an
radical
weakly
bound
copper
complex.
The
allyl
fragment
copper-mediated
regio-
stereocontrolled
coupling
group
under
influence
of
chiral
N-heterocyclic
carbene
ligand.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(10)
Опубликована: Янв. 10, 2022
Chiral
hydrogen-bonding
(H-bonding)
catalytic
asymmetric
conjugate
addition
to
activated
olefins
has
been
widely
used
access
enantioenriched
molecules
containing
stereocenters
at
the
β-position
of
olefin
activating
groups.
Herein,
we
report
first
highly
enantioselective
radical-based
manifold.
Under
a
dual
organocatalyst
system
involving
chiral
phosphoric
acid
and
DPZ
as
photoredox
sensitizer,
transformations
N-arylglycines,
in
which
aryls
with
CF3
substituents
are
introduced,
alkenyl
azaarenes
afforded
valuable
hydroaminoalkylation
adducts
satisfactory
results.
In
diversity
azaarenes,
method
can
be
construct
aryl-,
alkyl-
silyl-substituted
stereocenter.
Control
experiments
density
functional
theory
calculations
were
performed
elucidate
plausible
reaction
mechanism
origin
stereoselectivity,
wherein
nonclassical
H-bonding
interactions
found
assist
catalysts
offering
sufficient
enantiocontrol.
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(36), С. 20141 - 20148
Опубликована: Авг. 28, 2023
Chemodivergent
synthesis
has
been
achieved
in
asymmetric
photocatalysis.
Under
a
dual
catalyst
system
consisting
of
chiral
phosphoric
acid
and
DPZ
as
photosensitizer,
different
inorganic
bases
enabled
the
formation
two
sets
valuable
products
from
three-component
radical
tandem
transformations
2-bromo-1-arylenthan-1-ones,
styrenes,
quinoxalin-2(1H)-ones.
The
key
to
success
was
distinct
pKa
environment,
which
radicals
that
formed
on
quinoxalin-2(1H)-one
rings
after
addition
processes
underwent
either
single-electron
oxidation
or
reduction.
In
addition,
this
work
represents
first
use
quinoxalin-2(1H)-ones
photoredox
catalysis.
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.
Chemistry - A European Journal,
Год журнала:
2020,
Номер
26(66), С. 15052 - 15064
Опубликована: Июль 2, 2020
Over
the
past
decades,
organometallic
complexes
with
precious
elements,
such
as
ruthenium
and
iridium,
are
widely
used
visible-light
photoredox
catalysts.
Recently,
more
based
on
earth-abundant
inexpensive
elements
have
been
sensitizers
in
photochemistry.
Although
photoexcited
state
lifetimes
of
iron
typically
shorter
than
those
traditional
photosensitizers,
utilization
catalysts
photochemistry
has
sprung
up
owing
to
their
abundance,
low
price,
nontoxicity,
novel
properties,
including
exhibiting
ligand
metal
charge
transfer
states.
This
concept
focuses
recent
advances
light-driven
catalysis
organic
transformations,
iron/photoredox
dual
catalysis,
light-induced
generation
active
The
prospect
for
future
this
field
is
also
discussed.
