Angewandte Chemie,
Год журнала:
2024,
Номер
136(42)
Опубликована: Июль 24, 2024
Abstract
The
homolysis
of
chemical
bonds
represents
one
the
most
fundamental
reactivities
excited
molecules.
Historically,
it
has
been
exploited
to
generate
radicals
under
ultraviolet
(UV)
light
irradiation.
However,
unlike
contemporary
radical‐generating
mechanisms,
direct
excitation
homolyze
and
produce
aliphatic
carbon‐centered
visible
remains
rare,
especially
in
metallaphotoredox
cross
couplings.
Herein,
we
present
our
design
dihydropyrimidoquinolinone
(DHPQ)
reagents
derived
from
ketones,
which
can
undergo
formal
deacylation
homolytic
C−C
bond
cleavage
release
alkyl
without
external
photocatalysts.
Spectroscopic
computational
analysis
reveal
unique
optical
structural
features
DHPQs,
rationalizing
their
faster
kinetics
radical
generation
than
a
structurally
similar
but
visible‐light
transparent
precursor.
Such
capability
allows
DHPQ
facilitate
wide
range
Ni‐metallaphotoredox
couplings
with
aryl,
alkynyl
acyl
halides.
Other
catalytic
non‐catalyzed
alkylative
transformations
DHPQs
are
also
feasible
various
acceptors.
We
believe
this
work
would
be
broad
interest,
aiding
synthetic
planning
simplified
operation
expanding
reach
photocatalyst‐free
approaches
cutting‐edge
research.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 7, 2025
The
homolytic
cleavage
of
C–C
bonds
adjacent
to
specific
functional
groups
has
lately
emerged
as
a
versatile
approach
for
molecular
diversification.
Despite
the
ubiquity
and
synthetic
utility
ketones,
radical
fragmentation
their
α-C–C
proven
be
formidable
challenge.
Here,
we
present
broadly
applicable
deacylative
strategy
designed
homolytically
cleave
aliphatic
ketones
various
complexities,
including
transformations
cycloalkanones
into
carboxylic
acids
tethered
C-centered
free
radicals
that
can
engaged
in
diverse
radical-based
processes.
method
involves
ketone
activation
through
treatment
with
hydrogen
peroxide,
yielding
gem-dihydroperoxides.
Subsequent
single-electron-transfer
reduction
mediated
by
low-valent
metal
complex
generates
alkyl
captured
selectively
radicophile
choice,
catalytic
cross-coupling.
logic
our
functionalization
is
exemplified
total
synthesis
14
natural
products,
one
analogue,
two
drugs
starting
from
readily
available
showcasing
its
transformative
power
settings.
This
obviates
need
reagents
allows
controlled
conversion
reconstructed
making
process
highly
across
spectrum
domains.
Herein,
we
report
a
formal
C–C
bond
azidation
and
cyanation
of
unactivated
aliphatic
ketones
using
commercially
available
tosyl
azide
cyanide,
respectively.
A
visible-light-mediated
organophotocatalyst
enables
radical
ketone-derived
pro-aromatic
dihydroquinazolinones
(under
mostly
redox-neutral
conditions)
as
supported
by
preliminary
mechanistic
studies.
These
metal-free
scalable
protocols
can
be
used
to
synthesize
tertiary,
secondary,
primary
alkyl
azides
nitriles
with
good
functional
group
tolerance
postsynthetic
diversification
the
group,
including
bioconjugation.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Июль 24, 2024
Abstract
The
homolysis
of
chemical
bonds
represents
one
the
most
fundamental
reactivities
excited
molecules.
Historically,
it
has
been
exploited
to
generate
radicals
under
ultraviolet
(UV)
light
irradiation.
However,
unlike
contemporary
radical‐generating
mechanisms,
direct
excitation
homolyze
and
produce
aliphatic
carbon‐centered
visible
remains
rare,
especially
in
metallaphotoredox
cross
couplings.
Herein,
we
present
our
design
dihydropyrimidoquinolinone
(DHPQ)
reagents
derived
from
ketones,
which
can
undergo
formal
deacylation
homolytic
C−C
bond
cleavage
release
alkyl
without
external
photocatalysts.
Spectroscopic
computational
analysis
reveal
unique
optical
structural
features
DHPQs,
rationalizing
their
faster
kinetics
radical
generation
than
a
structurally
similar
but
visible‐light
transparent
precursor.
Such
capability
allows
DHPQ
facilitate
wide
range
Ni‐metallaphotoredox
couplings
with
aryl,
alkynyl
acyl
halides.
Other
catalytic
non‐catalyzed
alkylative
transformations
DHPQs
are
also
feasible
various
acceptors.
We
believe
this
work
would
be
broad
interest,
aiding
synthetic
planning
simplified
operation
expanding
reach
photocatalyst‐free
approaches
cutting‐edge
research.
Chemical Communications,
Год журнала:
2024,
Номер
60(62), С. 8095 - 8098
Опубликована: Янв. 1, 2024
Metal-free,
photoredox-catalyzed
aromatization-driven
deconstructive
functionalization
of
spiro-dihydroquinazolinones
with
α-CF
3
alkenes
is
achieved
high
chemoselectivity.
Mechanistic
studies
suggest
a
radical
pathway
for
this
cascade
reaction.
Chemistry - A European Journal,
Год журнала:
2024,
Номер
30(58)
Опубликована: Авг. 8, 2024
Abstract
Mild
and
inexpensive
copper‐catalyzed
aromatization‐driven
ring‐opening
amination
oxygenation
of
spiro
dihydroquinazolinones
are
presented,
respectively.
These
protocols
provide
facile
atom‐economical
access
to
the
aminated
carbonyl‐containing
quinazolin‐4(3
H
)‐ones
in
good
yields
with
functional
group
compatibility,
which
difficult
obtain
by
conventional
methods.
Remarkably,
a
telescoped
procedure
involving
condensation
ring‐opening/functionalization
for
simple
cycloalkanone
was
found
be
accessible.
Mechanistic
studies
suggest
radical
pathway
this
transformation.
Organic Letters,
Год журнала:
2024,
Номер
26(35), С. 7442 - 7446
Опубликована: Авг. 26, 2024
A
visible
light-promoted
aromatization-driven
deconstructive
fluorination
of
spiro
carbocycles
is
presented.
series
dihydroquinazolinones
reacted
efficiently
with
NFSI
under
light
irradiation
to
afford
the
2-(4-fluoroalkyl)quinazolin-4(3H)-ones
in
good
yields
excellent
functional
group
tolerance.
radical
pathway
involving
C–C
bond
cleavage
and
F
atom
transfer
proposed
for
reaction.
In
addition,
ring-opening
chlorination
NCS
was
also
applicable.
The Journal of Organic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 13, 2025
A
novel
and
robust
deconstructive
functionalization
reaction
of
spiro-dihydroquinazolinones
with
sulfenylating
reagents
in
the
presence
base
has
been
realized
under
visible
light
irradiation.
This
enabled
direct
ring-opening
unstrained
cyclic
ring
systems,
producing
skeletally
diverse
functionalized
quinazolinones
moderate
to
good
yields.
range
variety
including
diaryl
disulfide,
thiosulfonate,
dithiosulfonate
1-[(trifluoromethyl)thio]-2,5-pyrrolidinedione
were
compatible
for
this
transformation.
In
addition,
diselenide
selenosulfonate
could
also
couple
form
C-Se
Bonds.
Mechanistic
studies
revealed
that
proceeds
via
a
radical-radical
coupling
pathway.
A
novel
aerobic
aldolization
approach
that
employs
aromatization-driven
C–C
bond
cleavage
for
the
deacetylation
of
unstrained
ketones
was
reported.
Various
primary
and
secondary
alcohols
were
generated
under
oxygen
atmosphere
without
any
catalysts.
