Chemistry - A European Journal,
Год журнала:
2023,
Номер
29(50)
Опубликована: Июнь 2, 2023
Alkyl
radical
precursors
are
essential
for
a
wide
variety
of
photocatalytic
and
3d-metal-catalyzed
C-C
bond
forming
reactions.
Neutral
organic
heterocycles
as
electroauxiliaries
such
4-alkyl
Hantzsch
esters
have
become
reliable
tools
alkyl
formation.
Here
we
show
that
2,2'-biquinoline-derived
alkyl-substituted
dihydroquinolines
act
competent
with
the
ability
to
form
primary,
secondary
tertiary
radicals.
Hydroalkylation
benzalmalononitriles
N-Boc
protected
diazenes
has
been
achieved
through
copper
catalysis
under
mild
conditions
50
°C
good
very
yields
up
85
%.
Furthermore,
dihydroquinolines'
reactivity
towards
denitrative
alkylation
nitroolefins
β-nitrostyrene
was
discovered.
Most
importantly,
released
biquinoline
can
be
recycled,
which
greatly
improves
overall
atom-economy
these
in
comparison
previous
N-heterocyclic
electroauxiliaries.
Synlett,
Год журнала:
2023,
Номер
34(11), С. 1241 - 1246
Опубликована: Фев. 8, 2023
Abstract
We
report
a
visible-light-mediated,
organophotoredox-catalyzed,
C(sp2)–H
alkylation
of
N-heteroarenes
with
dihydroquinazolines,
prepared
from
aliphatic
ketones,
under
oxidative
conditions.
This
protocol
represents
metal-free
approach
to
the
effective
construction
C–C
bonds
through
Minisci-type
reaction,
formally
activating
native
C–H
bond
N-heteroarene
and
an
α-C–C
readily
available
ketone.
The
mild
nature
this
method
accommodates
wide
variety
tolerating
range
functional
groups.
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.
Organic Letters,
Год журнала:
2023,
Номер
25(33), С. 6200 - 6205
Опубликована: Авг. 14, 2023
Herein,
we
demonstrate
the
synthesis
and
characterization
of
bench
stable
tri/difluoromethylating
reagents
their
potential
applications
in
redox
neutral
hydro
tri/difluoromethylation
alkenes
enabled
by
visible
light.
The
new
are
obtained
on
a
gram-scale
through
simply
cyclocondensation
commercially
available
anthranilamide
with
phenyltrifluoro
or
difluoromethyl
ketone.
Preliminary
mechanistic
studies
indicated
that
canonical
photoredox
catalytic
cycle
is
being
operative.
DFT
support
this
further
reveal
deprotonation
occurs
before
radical
cleavage.
also
show
better
yield
HCF2
reagent
attributed
to
favorable
expulsion
corresponding
moiety.
Organic Chemistry Frontiers,
Год журнала:
2023,
Номер
10(24), С. 6205 - 6211
Опубликована: Янв. 1, 2023
A
practical
strategy
for
the
photoinduced
defluorinative
alkylation
of
α-trifluoromethyl
styrenes
with
carbonyl
derivatives
via
C–C
bond
cleavage
was
disclosed.
Organic & Biomolecular Chemistry,
Год журнала:
2024,
Номер
22(27), С. 5561 - 5568
Опубликована: Янв. 1, 2024
An
organo-photoredox
catalyzed
defluorinative
alkylation
of
ketone-derived
dihydroquinazolinones
with
α-trifluoromethyl
alkenes
is
described,
providing
a
facile
access
to
diverse
set
gem
-difluoroalkenes.
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.
The Journal of Organic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 13, 2025
A
class
of
prearomatic
carboxylic
acid
p-quinol
ester
radical
precursors
has
been
developed
successfully,
which
could
undergo
homolytic
cleavage
the
para
C-O
bond
esters
via
pyridine-boryl
radical-induced
aromatization
in
presence
pyridines
and
diboron
reagents,
affording
corresponding
alkyl
decarboxylation
from
carboxyl
situ.
In
addition,
were
further
applied
substitution
with
phenylsulfonyl
compounds
self-coulpings.
This
method
not
only
provides
a
new
approach
to
generation
intermediate
but
also
expands
application
boron
radicals.
Chinese Journal of Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 29, 2025
Comprehensive
Summary
Herein,
we
report
an
unprecedented
molecular
editing
strategy
for
cycloketones
that
involves
the
precise
translocation
and
removal
of
single
oxygen
atom
enabled
by
dual
photoexcited
palladium
photoredox
catalysis.
In
contrast
to
conventional
ketone
strategies,
which
often
rely
on
loss
pre‐functionalized
groups
or
addition
additional
acylating
agents,
this
approach
facilitates
efficient
recycling
moieties.
This
is
accomplished
through
a
catalyzed
N–O
bond
cleavage
cycloketone
oxime
esters,
generating
cyanoalkyl
radicals
carboxylate
complex.
The
subsequent
photoredox‐catalyzed
deoxygenation,
mediated
phosphoranyl
radicals,
then
leads
coupling
ultimately
yielding
desired
products.
features
good
economy
due
skeletal
modifications,
broad
compatibility
with
various
functional
groups,
significant
potential
late‐stage
functionalization
pharmaceutical
derivatives.
Chemistry - A European Journal,
Год журнала:
2023,
Номер
29(45)
Опубликована: Июнь 3, 2023
The
hydrosilylation
of
alkenes
is
one
the
most
important
methods
for
synthesis
organosilicon
compounds.
In
addition
to
platinum-catalyzed
hydrosilylation,
silyl
radical
reactions
are
notable
as
economic
reactions.
An
efficient
and
widely
applicable
reaction
was
developed
by
using
2-silylated
dihydroquinazolinone
derivatives
under
photocatalytic
conditions.
Electron-deficient
styrene
underwent
give
products
in
good
high
yields.
Mechanistic
studies
indicated
that
photocatalyst
functioned
not
a
photoredox
catalyst
but
an
energy
transfer
catalyst.
DFT
calculations
clarified
triplet
excited
state
released
through
homolytic
cleavage
carbon-silicon
bond,
this
followed
hydrogen
atom
pathway,
redox
pathway.
Chinese Journal of Organic Chemistry,
Год журнала:
2024,
Номер
44(5), С. 1549 - 1549
Опубликована: Янв. 1, 2024
The
visible-light-induced
C-C
bond
cleavage
of
dihydroquinazolinone
to
generate
alkyl
radicals
for
defluorinated
alkylation
reactions
with
α-trifluoromethyl
alkene
is
reported.The
method
featured
as
transition-metal-free,
mild
conditions,
base-or
additive-free,
and
has
a
wide
range
substrate
applicability,
which
provides
convenient
efficient
new
the
synthesis
various
alkyl-substituted
gem-difluoroalkene.
