The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(11), С. 7070 - 7074
Опубликована: Май 16, 2023
We
report
herein
the
synthesis
of
exo-chalcogenated
methylene
chroman-3-ones
via
palladium-catalyzed
intramolecular
acyl-chalcogenation
alkyne
with
thio-
and
selenoesters.
Chalcogen
containing
tetrasubstituted
alkenes
are
obtained
stereoselectively.
This
protocol
tolerates
various
functional
groups
heterocycles,
affording
chroman-3-one
products
in
moderate-to-good
yields.
Accounts of Chemical Research,
Год журнала:
2023,
Номер
56(16), С. 2170 - 2184
Опубликована: Июль 28, 2023
ConspectusSynthetic
chemists
have
consistently
aimed
to
develop
efficient
methods
for
synthesizing
ketones,
which
are
essential
building
blocks
in
organic
chemistry
and
play
significant
roles
bioactive
molecules.
Recent
efforts
focused
on
using
photoredox
catalysis,
enables
previously
inaccessible
activation
modes,
synthesize
ketones
through
the
cross-coupling
of
an
acyl
electrophile
simple
C(sp3)-H
bonds.
Over
past
few
years,
we
worked
developing
effective
versatile
approaches
directly
acylating
activated
hydrocarbons
forge
ketones.Initially,
thioesters
were
explored
as
source
achieve
direct
acylation
ethers,
but
unexpected
thioesterification
reaction
was
observed
instead.
To
gain
insights
into
this
reactivity,
conducted
optimization
conditions,
substrate
scope
evaluation,
mechanistic
studies.
Drawing
from
our
understanding
Ni/Ir
photocatalysis
obtained
study,
subsequently
developed
a
method
hydrocarbons.
The
use
less-reactive
amides
electrophiles
found
be
critical
suppressing
undesired
pathways.
This
seemingly
counterintuitive
reactivity
carefully
studied,
revealing
substrate-assisted
mechanism
suppressed
oxidative
addition
leads
early-stage
nickel
oxidation
C-H
activation.To
address
drawbacks
method,
primarily
arose
decarbonylative
transmetallative
side
pathways,
employed
N-acyllutidiniums
electrophile.
prevented
decomposition
enabling
α-chiral
substrates
with
retention
their
stereochemistry,
particularly
those
derived
α-amino
acids.
methodology
allowed
us
access
diverse
range
homologues.Despite
elegant
utility
Ni/photoredox
catalysis
new
synthetic
methodologies,
precise
behavior
catalysts
under
redox
conditions
is
incompletely
understood.
insight
chemical
reactions,
used
combination
experimental
computational
methods.
Our
investigations
revealed
that
devised
adjustments
nickel/photoredox
can
result
differences
outcomes,
providing
opportunities
tailor
reactions
designed
strategies.
We
believe
continued
study
apply
modulation
will
lead
discovery
additional
transformations.
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(7), С. 4607 - 4618
Опубликована: Март 21, 2024
We
have
developed
a
visible-light-driven
method
for
thioester
synthesis
that
relies
on
the
unique
dual
role
of
thiobenzoic
acids
as
one-electron
reducing
agents
and
reactants
leading
to
formation
sulfur
radical
species.
This
synthetic
process
offers
wide
scope,
accommodating
various
thioacid
thiol
substrates
without
need
photocatalyst.
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(12), С. 8357 - 8362
Опубликована: Май 31, 2024
Oxidation
contributes
as
a
secondary
driver
of
the
prevailing
carbon
emission
in
chemical
industries.
To
address
this
issue,
photocatalytic
aerobic
oxidation
has
emerged
promising
alternative.
However,
challenge
achieving
satisfactory
chemoselectivity
and
effective
use
solar
light
hindered
progress
area.
In
context,
present
study
introduces
novel
homogeneous
photocatalyst,
[Sm6O(OH)8(H2O)24]I8(H2O)8
cluster
(Sm-OC),
via
unique
auxiliary
ligand-free
oxidative
hydrolysis.
Using
Sm-OC
catalyst,
photocatalyzed
thiols
been
developed
for
synthesis
valuable
disulfides.
Remarkably,
catalyst
manifested
significant
turnover
number
≥2000
under
tested
conditions.
Sm-OC-catalyzed
showcased
remarkable
chemoselectivity.
thiol
oxidations,
despite
vulnerability
disulfides
toward
overoxidation,
overoxidized
byproducts
or
nontarget
functional
groups
was
not
detected
across
all
28
substrates.
This
investigation
presents
first
application
lanthanide-oxo/hydroxy
photocatalysis.
This
work
demonstrates
Cu–NHC
(NHC
=
N-heterocyclic
carbene)
catalyzed
alkynylation
of
aryl
thianthrenium
salts
via
thiazol-2-ylidene
ligands,
achieving
a
Pd-free
Sonogashira
coupling
with
broad
substrate
compatibility
and
functional
group
tolerance.
Late-stage
pharmaceutical
rare
alkynylative
C–H
functionalization/ring-opening
pathways
are
enabled.
Thiazol-2-ylidenes,
featuring
"half-umbrella"-shaped
geometry,
exhibit
superior
catalytic
performance
over
traditional
imidazol-2-ylidenes,
underscoring
their
unique
ligand
efficacy.
catalysis
enables
the
use
as
versatile
electrophiles
for
diverse
cross-couplings
under
mild
conditions.
Organic Letters,
Год журнала:
2023,
Номер
25(35), С. 6495 - 6500
Опубликована: Авг. 30, 2023
Here,
we
report
the
first
catalytic
enantioselective
1,4-addition
of
diarylphosphine
oxides
to
α,β-unsaturated
thioesters.
Importantly,
most
common
and
commercial
oxazaborolidine
(CBS)
was
employed
as
a
catalyst
for
its
new
application
without
being
activated
by
strong
protonic
acids
or
Lewis
led
chiral
thioesters
in
excellent
yields
enantioselectivities.
Furthermore,
this
method
features
mild
reaction
conditions
(room
temperature
air-insensitive),
good
substrate
tolerance,
easy
scalability.
Green Chemistry,
Год журнала:
2023,
Номер
25(13), С. 5035 - 5040
Опубликована: Янв. 1, 2023
The
conversion
of
unactivated
C(sp
3
)–H
to
)–S
bond
was
realized
through
a
light-induced
radical
relay
way
involving
successive
SET
and
HAT
process.
Ketones
could
be
prepared
from
thioacids
by
tandem
photocatalytic
coupling
reaction.
