European Journal of Organic Chemistry,
Год журнала:
2024,
Номер
27(44)
Опубликована: Окт. 24, 2024
Abstract
Organic
transformations
initiated
by
photochemical
activation
have
been
at
the
forefront
of
reaction
discovery.
In
this
study,
we
present
a
formal
[3+2]
and
[4+2]
cycloaddition
using
N
‐aryl
cyclopropylamines
cyclobutylamines
in
conjunction
with
α
,
β
‐unsaturated
carbonyl
systems,
unveiling
two
distinct
mechanistic
pathways.
The
is
elucidated
as
being
guided
activity
an
electron
donor‐acceptor
(EDA)
complex.
Simultaneously,
intermolecular
annulation
cyclobutylanilines
achieved
visible‐light
photoredox
catalysis.
These
simple
methodologies
wide
applicability,
facilitating
synthesis
‐arylaminocycloalkyl
compounds
yields
ranging
from
good
to
excellent.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 2, 2025
Regiodivergent
asymmetric
synthesis
represents
a
transformative
strategy
for
the
efficient
generation
of
structurally
diverse
chiral
products
from
single
set
starting
materials,
significantly
enriching
their
enantiomeric
composition.
However,
design
radical-mediated
regiodivergent
and
enantioselective
reactions
that
can
accommodate
wide
range
functional
groups
substrates
has
posed
significant
challenges.
The
obstacles
primarily
lie
in
switching
regioselectivity
achieving
high
enantiodiscrimination,
especially
when
dealing
with
high-energy
intermediates.
To
address
these
issues,
we
have
developed
new
catalytic
system
integrates
photoinduced
hydrogen
atom
transfer
(HAT)
copper
catalysis,
involving
fine-tuning
ligands,
additives,
other
reaction
parameters.
facilitates
cross-couplings
between
N-aryl
glycine
ester/amide
derivatives
abundant
hydrocarbon
feedstocks
through
strong
C(sp3)–H
bond
activation.
This
approach
allows
controlled
stereoselective
formation
C(sp3)–C(sp3)
C(sp3)–N
bonds,
yielding
rich
variety
C-
or
N-alkylated
esters
amides
commendable
yields
(up
to
92%
yield),
exclusive
regioselectivities
(typically
>20:1
rr),
enantioselectivities
96%
ee).
Our
methodology
not
only
provides
promising
avenue
incorporation
alkyl
functionalities
onto
specific
sites
biologically
molecules
but
also
offers
practical
while
simultaneously
induction
within
photochemical
reactions.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(8), С. 5580 - 5596
Опубликована: Фев. 12, 2024
Under
mild
blue-light
irradiation,
α-acylated
saturated
heterocycles
undergo
a
photomediated
one-atom
ring
contraction
that
extrudes
heteroatom
from
the
cyclic
core.
However,
for
nitrogenous
heterocycles,
this
powerful
skeletal
edit
has
been
limited
to
substrates
bearing
electron-withdrawing
substituents
on
nitrogen.
Moreover,
mechanism
and
wavelength-dependent
efficiency
of
transformation
have
remained
unclear.
In
work,
we
increased
electron
richness
nitrogen
in
azacycles
improve
light
absorption
strengthen
critical
intramolecular
hydrogen
bonding
while
enabling
direct
installation
photoreactive
handle.
As
result,
broadly
expanded
substrate
scope,
including
underexplored
electron-rich
previously
unsuccessful
now
achieved.
The
significantly
improved
yields
diastereoselectivities
facilitated
reaction
rate,
kinetic
isotope
effect
(KIE),
quenching
studies,
addition
determination
quantum
yields.
Guided
by
these
propose
revised
ET/PT
contraction,
which
is
additionally
corroborated
computational
characterization
lowest-energy
excited
states
through
time-dependent
DFT.
at
wavelengths
longer
than
those
strongly
absorbed
was
investigated
rate
measurements,
revealed
red
shift
photochemical
action
plot
relative
absorbance.
elucidated
mechanistic
photophysical
details
effectively
rationalize
empirical
observations,
additive
effects,
were
poorly
understood.
Our
findings
not
only
demonstrate
enhanced
synthetic
utility
shed
but
may
also
offer
valuable
guidance
understanding
reactivity
related
systems.
Organic Letters,
Год журнала:
2024,
Номер
26(15), С. 3151 - 3157
Опубликована: Апрель 2, 2024
A
facile
iron(II)-catalyzed
radical
[3
+
2]
cyclization
of
N-aryl
cyclopropylamines
with
various
alkenes
to
access
the
structurally
polyfunctionalized
cyclopentylamine
scaffolds
has
been
developed.
Using
low-cost
FeCl2·4H2O
as
catalyst,
could
be
utilized
react
a
wide
range
including
exocyclic/acyclic
terminal
alkenes,
cycloalkenes,
from
natural-occurring
compounds
(Alantolactone,
Costunolide),
and
known
drugs
(Ibuprofen,
l-phenylalanine,
Flurbiprofen)
obtain
variety
cyclopentylamines
fused
different
useful
motifs
in
generally
good
yields
diastereoselectivities.
The
highlight
this
protocol
is
also
featured
by
no
extra
oxidant,
base,
EtOH
solvent,
gram-scale
synthesis,
further
diverse
transformations
synthetic
products.
More
importantly,
an
iron(II)-mediated
hydrogen
dissociation
pathway
was
proposed
based
on
mechanism
research
experiments.
Organic Letters,
Год журнала:
2024,
Номер
26(15), С. 3294 - 3298
Опубликована: Апрель 3, 2024
A
(3
+
3)
annulation
of
aminocyclopropanes
and
vinyldiazo
compounds
enabled
by
organo-photocatalysis
is
described.
The
reaction
allows
the
regioselective
synthesis
cyclohexenes
bearing
adjacent
amino
carbonyl
groups
with
broad
functional
group
tolerance.
In
a
departure
from
previous
reports,
our
work
demonstrated
that
distonic
radical
cation
can
be
preferentially
intercepted
weakly
nucleophilic
compounds,
followed
an
exclusive
6-endo
cyclization
for
ring
closure.
Based
on
interaction
between
ester
groups,
products
further
converted
to
cyclohexene-fused
1,3-oxazinane
azetidine.
Advanced Synthesis & Catalysis,
Год журнала:
2023,
Номер
365(18), С. 3044 - 3062
Опубликована: Июль 28, 2023
Abstract
Chiral
phosphoric
acid
(
CPA
)
has
been
established
as
a
cornerstone
in
chemical
synthesis
reactions
for
over
five
decades,
owing
to
its
distinctive
molecular
structure
and
remarkable
catalytic
effect.
However,
recent
years,
revolutionary
approach
asymmetric
emerged,
utilizing
photocatalytic
excitation
of
molecules
generate
free
radicals,
effectively
surpassing
the
limitations
classical
organic
methodologies.A
prominent
significant
area
research
dedicated
investigation
chiral
synergistic
photocatalysis
enantioselective
synthesis.
This
unique
system
encompasses
bifunctional
hydrogen‐bonding
catalyst,
enabling
simultaneous
interactions
between
radical
intermediates
substrates.
The
review
paper
focuses
on
application
progress
this
throughout
past
decade.
Asian Journal of Organic Chemistry,
Год журнала:
2023,
Номер
12(10)
Опубликована: Авг. 23, 2023
Abstract
In
the
last
two
decades,
chiral
hydrogen
bonding
catalysis
has
been
enormously
utilized
to
trigger
several
valuable
synthetic
transformations.
Similarly,
modern
day
radical
chemistry
witnessed
potency
of
visible
light
photoredox
generate
radicals
via
single
electron
transfer
pathway.
Recently,
their
cooperative
effect
proved
be
a
key
strategy
access
many
elegant
transformations
that
are
only
feasible
under
synergistic
action
these
catalytic
systems.
This
dual
system
demonstrates
high
efficiency
for
introducing
molecular
complexity
in
an
enantioselective
fashion.
this
mini
review,
we
have
compiled
most
recent
development
surfaced
three
years
with
particular
attention
paid
mechanistic
details
and
its
substrate
scope.
We
hope
review
will
provide
readers
brief
overview
advancement
application
catalysts
bond
donors
reactions.
Chemical Science,
Год журнала:
2024,
Номер
15(17), С. 6507 - 6514
Опубликована: Янв. 1, 2024
Photocatalyzed
[4
+
2]
cycloaddition
of
benzocyclobutylamines
with
α-substituted
vinylketones
afforded
benzocyclohexylamines
in
moderate
to
good
yields
excellent
diastereoselectivities.
An
asymmetric
version
this
was
preliminarily
investigated.
Organic Chemistry Frontiers,
Год журнала:
2024,
Номер
11(21), С. 6042 - 6047
Опубликована: Янв. 1, 2024
A
photoredox-catalyzed
radical
cross–coupling
protocol
for
the
synthesis
of
β-amino
acid
derivatives
has
been
developed.
This
atom-economic
enables
a
range
esters
in
moderate
to
excellent
yields.
