Synlett,
Год журнала:
2023,
Номер
35(03), С. 362 - 366
Опубликована: Авг. 29, 2023
Abstract
Although
radical
cation
Diels–Alder
reactions
enable
the
formation
of
cyclohexene
ring
systems
between
electronically
mismatched
(both
electron-rich)
dienes
and
dienophiles,
which
is
otherwise
difficult
or
impossible
to
achieve
under
thermal
conditions,
substrate
scope
has
been
limited.
Herein,
we
disclose
that
a
reaction
using
an
enol
ether
as
electron-rich
(and
therefore
oxidizable)
dienophile
possible
through
rationally
designed
redox
tag
strategy.
Electrochemical
TiO2
photochemical
approaches
are
effective
in
driving
reaction,
where
both
intermolecular
intramolecular
electron
transfers
key.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(37), С. 25799 - 25812
Опубликована: Сен. 3, 2024
Photocatalysis
holds
great
promise
for
changing
the
way
value-added
molecules
are
currently
prepared.
However,
many
photocatalytic
reactions
suffer
from
quantum
yields
well
below
10%,
hampering
transition
lab-scale
to
large-scale
or
even
industrial
applications.
Molecular
dyads
can
be
designed
such
that
beneficial
properties
of
inorganic
and
organic
chromophores
combined,
resulting
in
milder
reaction
conditions
improved
reactions.
We
have
developed
a
novel
approach
obtaining
advantages
molecular
without
time-
resource-consuming
synthesis
these
tailored
photocatalysts.
Simply
by
mixing
cationic
ruthenium
complex
with
an
anionic
pyrene
derivative
water
salt
bichromophore
is
produced
owing
electrostatic
interactions.
The
long-lived
triplet
state
obtained
static
quantitative
energy
transfer
preorganized
complex.
exploited
this
so-called
Coulombic
dyad
catalysis
similar
reactivity
higher
photostability
compared
reference
photosensitizers
several
photooxygenations.
In
addition,
it
was
shown
system
also
used
maximize
yield
photoredox
This
due
intrinsically
cage
escape
after
photoinduced
electron
purely
compounds
heavy
atom-containing
molecules.
combination
laboratory-scale
as
mechanistic
irradiation
experiments
detailed
spectroscopic
investigations
provided
deep
insights
into
easy-to-use
photocatalyst
class.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(18), С. 12691 - 12701
Опубликована: Апрель 27, 2024
Aliphatic
strained
rings
have
been
increasingly
applied
in
medicinal
chemistry
due
to
their
beneficial
physicochemical
and
pharmacokinetic
properties.
However,
the
divergent
synthesis
of
enantioenriched
cyclobutane
derivatives
with
various
structural
patterns
continues
be
a
significant
challenge.
Here,
we
disclose
palladium-catalyzed
enantioselective
desymmetrization
cyclobutenes,
resulting
series
hydroarylation
1,2-
1,3-diarylation
products
via
interceptions
common
Heck
intermediate.
Mechanistic
investigations
provide
valuable
insights
into
understanding
catalytic
mode
palladium
catalysts
observed
variations
deuterium-responsive
behavior
during
reactions.
Furthermore,
synthetic
utility
is
demonstrated
syntheses
deuterated
drug
candidate
belaperidone
skeletons
pseudosymmetrical
truxinic
acid-type
derivatives.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 24, 2024
Although
photoredox
catalysis
is
complex
from
a
mechanistic
point
of
view,
it
also
often
surprisingly
efficient.
In
fact,
the
quantum
efficiency
puzzlingly
large
portion
reactions
exceeds
100%
(i.e.,
measured
yields
(QYs)
are
>1).
Hence,
these
can
be
A
palladium-catalyzed
alkoxycarbonylation
with
two
different
alcohols
for
the
synthesis
of
cyclobutanecarboxylates
bearing
an
α-quaternary
carbon
center
is
presented.
The
reaction
utilizes
readily
accessible
starting
materials,
tolerates
a
broad
scope
functional
groups,
and
provides
straightforward
efficient
approach
diverse
array
carbon.
Meanwhile,
this
strategy
effectively
prevents
transition-metal-catalyzed
ring-opening
cyclobutanols,
preserves
cyclobutane
framework,
affords
1,1-disubstituted
in
high
yields
excellent
regioisomeric
ratios.
Organic Letters,
Год журнала:
2025,
Номер
27(10), С. 2509 - 2514
Опубликована: Март 5, 2025
Chiral
cyclobutanamide
is
a
privileged
scaffold
in
drug
discovery.
Here,
we
describe,
for
the
first
time,
synthesis
of
axially
chiral
cyclobutanamides
via
phosphoric
acid-catalyzed
enantioselective
condensation
between
N-arylcarbamyl
cyclobutanones
and
hydroxylamines.
Rational
substrate
design,
incorporating
an
amide
moiety
(CONHR)
into
cyclobutanone
backbone
formation
multi-hydrogen
bonding
network
involving
N-H
this
portion,
responsible
excellent
enantioselectivity
achieved
stereodetermining
dehydration
process,
which
supported
by
detailed
mechanistic
study.
This
study
presents
a
novel,
eco-friendly,
and
cost-effective
magnetic
hybrid
photocatalyst,
Fe3O4@SiO2/L-tryptophan,
synthesized
through
scalable
three-step
green
approach
using
natural
agricultural
waste.
The
Fe3O4@SiO2/L-tryptophan
nanoparticle
features
core-shell
structure
with
high
surface
area
(63.14
m2/g),
strong
visible-light
absorption
(λ
>
448
nm),
narrow
band
gap
(1.84
eV),
superparamagnetic
properties
(22
emu/g),
enabling
efficient
separation
reusability.
Characterization
techniques
(XRD,
XPS,
FT-IR,
FE-SEM,
HR-TEM,
UV-vis
DRS,
TGA,
BET,
EIS)
confirmed
its
structural
stability,
charge
separation,
interfacial
transport.
photocatalyst
achieved
82.1%
oxidative
desulfurization
of
dibenzothiophene
(DBT)
conversion
rates
for
toluene
(85%)
styrene
(90%)
under
visible
light
O2
as
an
oxidant.
It
retained
over
85%
activity
after
five
cycles,
demonstrating
excellent
durability.
For
the
first
time,
all
components
are
derived
from
sources:
Fe3O4
sorghum
seed
extract,
SiO2
rice
husk,
L-tryptophan
enhanced
separation.
sustainable
synthesis
reduces
chemical
waste
energy
consumption,
setting
new
benchmark
environmentally
friendly
photocatalysts.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 21, 2025
The
discovery
of
new
chemoselectivity
with
readily
accessible
chemicals
is
important
to
expand
the
reaction
space
for
modern
chemistry.
For
dienes
and
dienophiles,
most
people
will
naturally
use
them
carry
out
classic
Diels-Alder
construct
six-membered
cyclic
compounds.
Here,
we
demonstrated
a
chemoselective
coupling
butadiene
dienophiles
through
stereoselective
1,3-cyclotelomerization.
By
utilizing
robust
Ni/IPr
catalysis,
valuable
bicyclic
products
were
created
high
regio-
chemoselectivities
under
mild
conditions.
Asymmetric
cyclotelomerization
enabled
by
chiral
NHC
ligand
was
also
performed,
generating
enantioenriched
mechanism
investigated
via
experiments
density
functional
theory
(DFT)
calculations,
which
indicate
that
might
start
oxidative
cyclometalation
between
two
molecules
1,3-diene
Ni(0)
species,
followed
[3
+
2]-cycloaddition
nickelacycle
dienophile.
can
undergo
variety
intricate
transformations,
emphasizes
potential
applications
this
strategy.
It
hoped
protocol
further
inspire
rethink
organic
reactions.
