The
saturation
of
aromatic
scaffolds
is
valuable
for
the
synthesis
complex
rings.
Herein,
we
demonstrate
a
process
photochemical
dearomative
reduction
quinolines.
involves
capture
quinoline
excited
state
with
γ-terpinene.
Importantly,
reaction
chemoselective
as
other
easily
reduced
functionalities
such
halogens
or
alkenes
do
not
undergo
reduction.
mechanism
has
also
been
investigated.
Finally,
generality
approach
towards
substrates
demonstrated.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(41)
Опубликована: Май 28, 2024
Dearomative
construction
of
multiply-fused
2D/3D
frameworks,
composed
aromatic
two-dimensional
(2D)
rings
and
saturated
three-dimensional
(3D)
rings,
from
readily
available
quinolines
has
greatly
contributed
to
drug
discovery.
However,
dearomative
cycloadditions
in
the
presence
photocatalysts
usually
afford
5,6,7,8-tetrahydroquinoline
(THQ)-based
polycycles,
access
1,2,3,4-THQ-based
structures
remains
limited.
Herein,
we
present
a
chemo-,
regio-,
diastereo-,
enantioselective
transformation
into
6-6-4-membered
without
any
catalyst,
through
combination
nucleophilic
addition
borate-mediated
[2+2]
photocycloaddition.
Detailed
mechanistic
studies
revealed
that
photoexcited
borate
complex,
generated
quinoline,
organolithium,
HB(pin),
accelerates
cycloaddition
suppresses
rearomatization
occurs
conventional
Based
on
our
analysis,
also
developed
further
photoinduced
affording
other
types
frameworks
isoquinoline
phenanthrene.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Июль 19, 2024
Abstract
Visible-light
photocatalysis
has
evolved
as
a
powerful
technique
to
enable
controllable
radical
reactions.
Exploring
unique
photocatalytic
mode
for
obtaining
new
chemoselectivity
and
product
diversity
is
of
great
significance.
Herein,
we
present
photo-induced
chemoselective
1,2-diheteroarylation
unactivated
alkenes
utilizing
halopyridines
quinolines.
The
ring-fused
azaarenes
serve
not
only
substrate,
but
also
potential
precursors
halogen-atom
abstraction
pyridyl
generation
in
this
photocatalysis.
As
complement
metal
catalysis,
process
with
mild
redox
neutral
conditions
assembles
two
different
heteroaryl
groups
into
regioselectively
contribute
broad
substrates
scope.
obtained
products
containing
aza-arene
units
permit
various
further
diversifications,
demonstrating
the
synthetic
utility
protocol.
We
anticipate
that
protocol
will
trigger
advancement
alkyl/aryl
halides
activation.
ACS Catalysis,
Год журнала:
2023,
Номер
13(7), С. 4894 - 4902
Опубликована: Март 27, 2023
C-4-selective
functionalization
of
azlactones
provides
access
to
α,α-disubstituted
unnatural
α-amino
acids,
which
has
been
extensively
investigated
in
the
past
decades.
However,
a
vast
majority
such
transformations
are
two-electron
transfer
reactions.
Herein,
leveraging
on
persistent
radical
effect,
we
develop
photocatalytic
energy
transfer-enabled
regioconvergent
alkylation
with
redox-active
esters
via
radical–radical
couplings.
This
strategy
is
extended
utilization
simple
alkanes
as
precursors,
whereby
aryl
play
dual
role
an
oxidant
and
hydrogen-atom-transfer
agent.
Notably,
excited
state
Ir(III)
photocatalyst
enables
selective
activation
unwanted
imine
products
through
triplet
transfer,
delivering
C-4-functionalized
high
regioselectivity.
Both
experimental
investigations
density
functional
theory
calculations
reaction
mechanism
were
performed,
supporting
EnT-enabled
coupling
pathways.
The
saturation
of
aromatic
scaffolds
is
valuable
for
the
synthesis
complex
rings.
Herein,
we
demonstrate
a
process
photochemical
dearomative
reduction
quinolines.
involves
capture
quinoline
excited
state
with
γ-terpinene.
Importantly,
reaction
chemoselective
as
other
easily
reduced
functionalities
such
halogens
or
alkenes
do
not
undergo
reduction.
mechanism
has
also
been
investigated.
Finally,
generality
approach
towards
substrates
demonstrated.
