Synlett,
Journal Year:
2023,
Volume and Issue:
35(03), P. 307 - 312
Published: June 26, 2023
Abstract
The
development
of
tunable
organic
photoredox
catalysts
remains
important
in
the
field
catalysis.
A
highly
modular
and
family
trianguleniums
(azadioxatriangulenium,
diazaoxatriangulenium,
triazatriangulenium),
related
[4]helicene
quinacridinium
have
been
used
as
for
photoreductions
photooxidations
under
visible
light
irradiation
(λ
=
518–640
nm).
highlight
this
is
their
readily
redox
properties,
leading
to
different
reactivities.
We
report
use
photocatalysts
aerobic
oxidative
hydroxylation
arylboronic
acids
cross-dehydrogenative
coupling
reaction
N-phenyl-1,2,3,5-tetrahydroisoquinoline
with
nitromethane
through
reductive
quenching.
Furthermore,
potential
photoreduction
has
demonstrated
catalysis
an
intermolecular
atom-transfer
radical
addition
via
These
transformations
serve
benchmarks
that
easily
synthesized
trianguleniums,
congeners
acridiniums,
are
versatile
applications
both
photoreductions.
JACS Au,
Journal Year:
2022,
Volume and Issue:
2(6), P. 1488 - 1503
Published: June 10, 2022
Photoredox
catalysis
typically
relies
on
the
use
of
single
chromophores,
whereas
strategies,
in
which
two
different
light
absorbers
are
combined,
rare.
In
photosystems
I
and
II
green
plants,
separate
chromophores
P680
P700
both
absorb
independently
one
another,
then
their
excitation
energy
is
combined
so-called
Z-scheme,
to
drive
an
overall
reaction
that
thermodynamically
very
demanding.
Here,
we
adapt
this
concept
perform
photoredox
reactions
organic
substrates
with
input
red
photons
instead
blue
or
UV
light.
Specifically,
a
CuI
bis(α-diimine)
complex
combination
situ
formed
9,10-dicyanoanthracenyl
radical
anion
presence
excess
diisopropylethylamine
catalyzes
ca.
50
dehalogenation
detosylation
reactions.
This
dual
approach
seems
useful
because
less
damaging
has
greater
penetration
depth
than
radiation.
UV-vis
transient
absorption
spectroscopy
reveals
subtle
change
solvent
from
acetonitrile
acetone
induces
changeover
mechanism,
involving
either
dominant
photoinduced
electron
transfer
triplet-triplet
pathway.
Our
study
illustrates
mechanistic
complexity
systems
operating
under
multiphotonic
conditions,
it
provides
insights
into
how
competition
between
desirable
unwanted
steps
can
become
more
controllable.
Journal of the American Chemical Society,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 10, 2025
Despite
the
progress
made
in
field
of
synthetic
organic
photocatalysis
over
past
decade,
use
higher
wavelengths,
especially
those
deep-red
portion
electromagnetic
spectrum,
remains
comparatively
rare.
We
have
previously
disclosed
that
a
well-defined
N,C,N-pincer
bismuthinidene
(1a)
can
undergo
formal
oxidative
addition
into
wide
range
aryl
electrophiles
upon
absorption
low-energy
red
light.
In
this
study,
we
map
out
photophysical
dynamics
1a
and
glean
insights
nature
excited
state
responsible
for
activation
electrophiles.
Transient
emission
techniques
reveal
that,
irradiation
with
light,
complex
undergoes
direct
S0
→
S1
metal-to-ligand
charge
transfer
(MLCT)
transition,
followed
by
rapid
intersystem
crossing
(ISC)
to
highly
reducing
emissive
triplet
(−2.61
V
vs
Fc+/0
MeCN).
The
low
dissipative
losses
incurred
during
ISC
(∼6%
incident
light
energy)
help
rationalize
ability
convert
useful
chemical
energy.
Spectroelectrochemical
computational
data
support
charge-separated
excited-state
structure
radical-anion
character
on
ligand
radical-cation
bismuth.
Kinetic
studies
competition
experiments
afford
mechanism
iodides;
concerted
inner-sphere
processes
from
are
ruled
out,
strongly
supporting
pathway
proceeds
via
outer-sphere
dissociative
electron
transfer.
Chemical Science,
Journal Year:
2022,
Volume and Issue:
13(20), P. 5973 - 5981
Published: Jan. 1, 2022
The
pinacol
coupling
reaction,
a
reductive
of
carbonyl
compounds
that
proceeds
through
the
formation
ketyl
radicals
in
presence
an
electron
donor,
affords
corresponding
1,2-diols
one
single
step.
photoredox
version
this
transformation
has
been
accomplished
using
different
organic
dyes
or
photoactive
metal
complexes
sacrificial
donors
such
as
tertiary
amines
Hantzsch's
ester.
Normally,
homo-coupling
reactive
is
neither
diastereo-
nor
enantio-selective.
Herein,
we
report
highly
diastereoselective
reaction
aromatic
aldehydes
promoted
by
5
mol%
non-toxic,
inexpensive
and
available
Cp2TiCl2
complex.
key
feature
allows
complete
control
diastereoselectivity
employment
red-absorbing
dye
redox-active
titanium
Taking
advantage
well-tailored
potential
dye,
selective
reduction
Ti(iv)
to
Ti(iii)
achieved.
These
conditions
enable
d,l
(syn)
diastereoisomer
favored
product
(d.r.
>
20
:
1
most
cases).
Moreover,
employing
simply
prepared
chiral
SalenTi
complex,
new
gave
diastereoselection
for
diastereoisomer,
high
enantiocontrol
(up
92%
enantiomeric
excess).
Advanced Synthesis & Catalysis,
Journal Year:
2023,
Volume and Issue:
365(4), P. 398 - 462
Published: Jan. 18, 2023
Abstract
The
difunctionalizative
trifluoromethylation
of
unsaturated
C−C
bonds
is
a
highly
useful
and
efficient
method
for
the
synthesis
trifluoromethyl
compounds
with
attractive
architectures
from
simple
feedstocks,
allowing
introduction
CF
3
group
along
wide
variety
substituents
either
inter‐
or
intramolecularly.
Given
that
molecules
are
increasingly
used
as
promising
bioactive
species
in
design
new
drugs
agrochemicals,
has
been
extensively
studied
during
last
decade.
This
review
focuses
on
reactions
proceeding
via
simultaneous
formation
C−heteroatom
(O,
N,
S,
Se,
B)
C−H
bonds,
these
provide
group‐containing
building
blocks.
To
identify
trends
prospects
evolution
this
methodology,
we
systematically
describe
variants
types
more
general
view
reaction
conditions,
modes,
mechanisms.
presented
comprehensive
survey
enables
categorization
into
those
synthetically
mature
room
further
development.
magnified
image
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(4), P. 2325 - 2332
Published: Jan. 17, 2024
The
only
known
method
for
the
dearomative
trifluoromethoxylation
of
indoles
is
preliminary,
with
one
substrate
successfully
undergoing
reaction.
In
this
study,
we
not
developed
a
broadly
applicable
indole
but
also
achieved
divergent
by
fine-tuning
reaction
conditions.
Under
optimized
conditions,
silver
salt
and
an
easily
handled
OCF3
reagent,
various
smoothly
underwent
dearomatization
to
afford
diverse
array
ditrifluoromethoxylated
indolines
in
50–84%
isolated
yields
up
37:1
diastereoselectivity,
fluorinated
trifluoromethoxylated
were
obtained
exclusive
trans
selectivity.
addition,
conditions
compatible
other
heteroaromatic
rings
as
well
styrene
moieties.
Chemical Communications,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 1, 2025
A
red-light
(
λ
=
640
nm)-mediated
C-3
formylation
of
indoles
utilizing
a
helical
carbenium
ion
as
photocatalyst
and
2,2-dimethoxy-
N
,
-dimethylethanamine
formylating
source
is
presented.
Organic Letters,
Journal Year:
2022,
Volume and Issue:
24(15), P. 2788 - 2792
Published: April 11, 2022
A
robust
and
green
electrochemical
dearomatization
of
indoles
was
developed
by
merging
a
fluorine-containing
group
to
an
indole
nucleus
under
oxidant-free
conditions,
delivering
diverse
array
tri-
difluoromethylated
3,3-spiroindolines
with
good
functional
tolerance.
