Phenothiazine Sulfoxides as Active Photocatalysts for the Synthesis of γ-Lactones
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 2, 2025
N-substituted
phenothiazines
are
prominent
and
highly
effective
organic
photoredox
catalysts,
particularly
known
for
their
strong
reducing
capabilities.
Despite
wide
utility,
the
closely
related
phenothiazine
sulfoxides,
which
easily
form
upon
oxidation,
have
been
largely
overlooked
not
explored
in
context
of
photocatalysis.
Herein,
we
describe
discovery
application
N-phenylphenothiazine
sulfoxide
as
a
photocatalyst
reductive
activation
cyclic
malonyl
peroxides,
giving
access
to
complex
γ-lactones
starting
from
simple
olefins.
Detailed
mechanistic
studies
were
carried
out
better
understand
situ
formation
active
catalyst
species
commercial
precursor,
well
interconversion
photocatalytic
mechanism
γ-lactone
products.
Specifically,
employed
broad
range
tools,
including
time-resolved
spectroscopy,
spectroelectrochemistry,
transient
UV-vis
absorption
voltammetry,
isotopic
labeling,
radical
trapping
experiments,
NMR
density
functional
theory
(DFT)
calculations.
The
synthetic
utility
this
protocol
is
demonstrated
substrate
scope
study,
highlighting
facile
spirocyclic
γ-lactones,
widely
recognized
biological
importance.
Язык: Английский
Strongly Oxidizing Thiapyrylium Salt for Organophotoredox Catalysis
Organic Letters,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 1, 2025
Photoredox
catalysis
has
garnered
significant
attention
in
organic
chemistry
for
its
ability
to
promote
chemical
transformations
under
visible-light
irradiation.
To
date,
research
on
salt-based
organophotoredox
catalysts
mainly
concentrated
the
development
of
oxygen-
and
nitrogen-based
such
as
acridinium
pyrylium
salts,
whereas
sulfur-containing
have
received
far
less
attention.
Herein,
we
report
a
strongly
oxidizing
tert-butyl-substituted
thiapyrylium
catalyst
(tBu-TTPP)
that
exhibits
high
excited-state
reduction
potential
(E1/2(C*/C•-)
=
+2.23
V
vs
SCE)
can
be
activated
by
blue
LEDs.
The
tBu-TTPP
provided
promising
results
various
photoredox
reactions,
radical-cation
Diels-Alder
trifluoromethylations,
[4
+
2]
annulation
alkynes
thiophene,
C-N
cross-coupling
fluoroarenes,
demonstrating
catalysis.
Язык: Английский
A Direct Oxidative Esterification of Aldehydes with Alcohols Mediated by Photochemical C-H Bromination
Organic & Biomolecular Chemistry,
Год журнала:
2024,
Номер
22(46), С. 9032 - 9035
Опубликована: Янв. 1, 2024
The
photochemical
direct
esterification
of
aldehydes
with
alcohols
Язык: Английский
Visible Light Excitation of Poly‐(para‐Phenylene Ethynylene) Enables Heterogeneous Photocatalytic Oxidations of Amines in Flow.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 22, 2024
Abstract
Heterogeneous
visible
light
photocatalysis
is
a
compelling
approach
to
address
sustainability
in
synthetic
photochemistry.
However,
the
use
of
solid‐state
photocatalysts
remains
very
unpopular
organic
synthesis
because
their
limited
accessibility
and
black‐box
effect
associated
lack
rational
between
molecular
structure
photochemical
properties.
Herein,
we
disclose
synthesis,
characterization,
photocatalytic
properties
applications
simple
readily
available
conjugated
polymer,
poly‐(
para
‐phenylene
ethynylene)
1
,
which
exhibits
strong
oxidative
power
upon
irradiation
with
(E(
1*
/
⋅
−
)=+1.67
V
vs
SCE).
Comparisons
structural
analogues
highlighted
superior
activity
this
linear
semiconductor,
on
account
its
fully
architecture.
The
excited‐state
reactivity
enabled
transformation
various
amines
into
imines
batch
continuous
flow
reactors
together
straightforward
photocatalyst
recycling.
Mechanistic
investigations
revealed
concomitant
photoredox
energy
transfer
pathways,
that
led
formation
desired
products.
Ultimately,
inline
generation
was
exploited
telescoped
three‐component
Ugi
reactions
(3CR)
toward
biologically
relevant
α‐acylaminoamides.
Язык: Английский
Organocatalytic hydrogen bond donor/Lewis base (HBD/LB) synthesis and chiroptical properties of thiabridged [5]helicenes
Organic & Biomolecular Chemistry,
Год журнала:
2024,
Номер
22(35), С. 7154 - 7163
Опубликована: Янв. 1, 2024
A
series
of
thiabridged
[5]helicenes
with
exceptional
configurational
stability
are
obtained
via
organocatalysis.
The
optical
and
CSP-HPLC
resolution
reported
the
chiroptical
properties
studied.
Язык: Английский
Visible Light Excitation of Poly‐(para‐Phenylene Ethynylene) Enables Heterogeneous Photocatalytic Oxidations of Amines in Flow.
Angewandte Chemie,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 22, 2024
Abstract
Heterogeneous
visible
light
photocatalysis
is
a
compelling
approach
to
address
sustainability
in
synthetic
photochemistry.
However,
the
use
of
solid‐state
photocatalysts
remains
very
unpopular
organic
synthesis
because
their
limited
accessibility
and
black‐box
effect
associated
lack
rational
between
molecular
structure
photochemical
properties.
Herein,
we
disclose
synthesis,
characterization,
photocatalytic
properties
applications
simple
readily
available
conjugated
polymer,
poly‐(
para
‐phenylene
ethynylene)
1
,
which
exhibits
strong
oxidative
power
upon
irradiation
with
(E(
1*
/
⋅
−
)=+1.67
V
vs
SCE).
Comparisons
structural
analogues
highlighted
superior
activity
this
linear
semiconductor,
on
account
its
fully
architecture.
The
excited‐state
reactivity
enabled
transformation
various
amines
into
imines
batch
continuous
flow
reactors
together
straightforward
photocatalyst
recycling.
Mechanistic
investigations
revealed
concomitant
photoredox
energy
transfer
pathways,
that
led
formation
desired
products.
Ultimately,
inline
generation
was
exploited
telescoped
three‐component
Ugi
reactions
(3CR)
toward
biologically
relevant
α‐acylaminoamides.
Язык: Английский