Angewandte Chemie,
Journal Year:
2022,
Volume and Issue:
134(48)
Published: Oct. 7, 2022
Abstract
The
synthesis
of
2‐azetidinones
(β‐lactams)
from
simple
acrylamide
starting
materials
by
visible‐light‐mediated
energy
transfer
catalysis
is
reported.
reaction
features
a
C(sp
3
)−H
functionalization
via
variation
the
Norrish–Yang
photocyclization
involving
carbon‐to‐carbon
1,5‐hydrogen
atom
(supported
deuterium
labelling
and
DFT
calculations)
can
be
used
for
construction
diverse
range
β‐lactam
products.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(39), P. 21576 - 21586
Published: Sept. 20, 2023
Alkenylboronates
are
versatile
building
blocks
for
stereocontrolled
synthesis
owing
to
the
traceless
nature
of
boron
group
that
can
be
leveraged
achieve
highly
selective
geometric
isomerization.
Using
thioxanthone
as
an
inexpensive
photocatalyst,
photoisomerization
these
species
continues
provide
expansive
platform
stereodivergent
synthesis,
particularly
in
construction
bioactive
polyenes.
Although
mechanistic
investigations
consistent
with
light-driven
energy
transfer,
direct
experimental
evidence
remains
conspicuously
absent.
Herein,
we
report
a
rigorous
investigation
using
two
widely
used
alkenylboronates
alongside
relevant
reference
compounds.
Through
combination
irradiation
experiments,
transient
absorption
spectroscopic
studies,
kinetic
modeling,
and
DFT
calculations
all
isomers
model
compounds,
it
has
been
possible
unequivocally
detect
characterize
perpendicular
triplet
generated
by
transfer.
Our
results
serve
not
only
blueprint
studies
challenging
organic
sensitizers,
but
guidelines
delineated
have
also
enabled
development
more
sustainable
reaction
conditions:
first
time,
efficient
organocatalytic
isomerization
under
sunlight
become
feasible.
Organic & Biomolecular Chemistry,
Journal Year:
2022,
Volume and Issue:
20(34), P. 6721 - 6740
Published: Jan. 1, 2022
Visible-light-induced
organic
small
molecule-catalysed
reactions
over
the
past
5
years
are
reviewed.
The
reaction
mechanisms
involving
photoinduced
single
electron
transfer
and
energy
also
discussed.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(48)
Published: Oct. 7, 2022
Abstract
The
synthesis
of
2‐azetidinones
(β‐lactams)
from
simple
acrylamide
starting
materials
by
visible‐light‐mediated
energy
transfer
catalysis
is
reported.
reaction
features
a
C(sp
3
)−H
functionalization
via
variation
the
Norrish–Yang
photocyclization
involving
carbon‐to‐carbon
1,5‐hydrogen
atom
(supported
deuterium
labelling
and
DFT
calculations)
can
be
used
for
construction
diverse
range
β‐lactam
products.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
63(7)
Published: Dec. 27, 2023
Herein,
we
report
the
use
of
isonitriles
as
alkyl
radical
precursors
in
light-mediated
hydro-
and
deuterodeamination
reactions.
The
reaction
is
scalable,
shows
broad
functional
group
compatibility
potential
to
be
used
late-stage
functionalization.
Importantly,
method
general
for
C
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(12), P. 2398 - 2402
Published: March 18, 2024
Herein,
we
introduce
a
tetralone-mediated
photocyclization
method
of
N-arylacrylamides.
The
protocol
proceeds
smoothly
to
deliver
diverse
set
3,4-dihydroquinolinones
in
moderate
good
yields
with
excellent
functional
group
compatibility
and
readily
allows
for
late-stage
modifications
number
complex
drug
molecules.
Mechanistic
studies
reveal
that
the
present
systems
ultraviolet
light
irradiation
enable
cyclization
via
energy
transfer
exclusive
1,3-hydrogen
shift.
Organic Letters,
Journal Year:
2021,
Volume and Issue:
24(1), P. 349 - 353
Published: Dec. 14, 2021
Metal-
and
additive-free
photoredox
cyclization
of
N-arylacrylamides
is
herein
reported
that
provides
a
concise
access
to
the
formation
dihydroquinolinones.
In
this
protocol,
sustainable
visible
light
was
used
as
energy
source,
organic
light-emitting
molecule
4CzIPN
served
efficient
photocatalyst.
This
reaction
system
features
exclusive
6-endo-trig
selectivity
with
generally
good
yield
range
functionalized
dihydroquinolinones
dihydrobenzoquinolinones.
Mechanistical
studies
reveal
feasibility
both
1,3-H
shift
intersystem
crossing
diradical
intermediate.
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
145(1), P. 171 - 178
Published: Dec. 26, 2022
Controlling
absolute
stereochemistry
in
catalytic
photochemical
reactions
is
generally
challenging
owing
to
high
rates
of
background
reactivity.
Successful
strategies
broadly
rely
on
selective
excitation
the
reaction
substrate
when
associated
with
a
chiral
catalyst.
Recent
studies
have
demonstrated
that
Lewis
acid
complexes
can
enable
energy
transfer
from
photosensitizer
facilitate
enantioselective
triplet
state
reactions.
Here,
we
apply
this
approach
catalysis
6π
photocyclization
through
design
an
iridium
optimized
undergo
only
presence
complex.
Among
group
iridium(III)
sensitizers,
enantioselectivity
and
yield
closely
correlate
photocatalyst
within
narrow
window
enabled
by
modest
reduction
upon
binding
scandium/ligand
These
results
demonstrate
tuning
offers
means
suppress
reactivity
improve
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(16), P. 2863 - 2867
Published: April 17, 2023
CBZ6,
a
redox-neutral
non-donor-acceptor-type
organo-photocatalyst,
presents
strong
reductive
potential
with
an
oxidative
of
-2.16
V
(vs
SCE).
It
can
work
as
photosensitizer
for
both
single-electron
transfer
and
triplet
energy
processes.
This
feature
enables
site-selective
control
in
the
intramolecular
hydroarylation
acrylamides.
Both
5-exo-trig
6-endo-trig
cyclization
products
could
be
prepared
regiospecfically
under
mild
conditions.
No
transition
metal,
halogen-containing
reagents,
or
additional
reductant
oxidant
is
involved.
process
provides
concise
environmentally
sustainable
access
to
series
oxindoles
dihydroquinolinones.
Catalysts,
Journal Year:
2023,
Volume and Issue:
13(7), P. 1105 - 1105
Published: July 15, 2023
Dihydroquinolin-2(1H)-ones
(DHQOs)
represent
a
class
of
valuable
bioactive
compounds
with
six-membered
nitrogen-containing
heterocyclic
structures.
The
development
simple,
mild,
and
efficient
synthetic
methods
has
been
widely
considered
by
chemists.
In
this
review,
we
have
summarized
series
different
strategies
for
the
synthesis
DHQOs
via
catalytic
annulation
α,β-unsaturated
N-arylamides
in
past
decade,
including
covering
electrophilic
cyclization,
radical
initiated
photochemical
cyclization
reactions.
Additionally,
substrate
scope
mechanistic
details
are
also
discussed.
This
paper
provides
useful
reference
diverse
methodologies
DHQO.
