ChemSusChem,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 23, 2024
Abstract
Spirocyclobutyl
oxindoles,
characterized
by
their
unique
three‐dimensional
structures,
are
valuable
building
blocks
for
many
pharmacophores
and
drug
units.
However,
stereoselective
synthetic
strategies
these
scaffolds
remain
underdeveloped,
with
most
existing
methods
relying
on
transition
metal
catalysts
stoichiometric
redox
reagents.
In
this
work,
we
introduce
an
electrochemical
strain‐release
driven
cascade
spirocyclization
of
bicyclo[1.1.0]butane
(BCB)
derivatives
the
synthesis
functionalized
spirocyclobutyl
oxindoles.
Tetrabutylammonium
bromide
serves
a
dual
purpose
as
both
supporting
electrolyte
brominating
agent.
The
method
offers
broad
substrate
scope,
high
atom
economy,
excellent
diastereoselectivity.
stereoselectivity
product
is
controlled
minimizing
dipolar
repulsion
between
amide
C=O
C−Br
bonds.
We
also
explored
methodology′s
versatility
applying
it
to
various
functionalizations
demonstrated
its
scalability
practical
use.
efficient
derivatization
products
allowed
rapid
creation
diverse
library
Nature Communications,
Journal Year:
2025,
Volume and Issue:
16(1)
Published: Jan. 24, 2025
C–C
bond
cleavage
and
recombination
provide
an
efficient
strategy
for
the
modification
reconstruction
of
molecule
structures.
Herein,
we
present
a
method
achieving
amidation
aryl
C(sp2)–H
through
triple
with
involvement
nitrous
acid
esters.
This
marks
instance
precise
controlled
stepwise
bond,
offering
fresh
perspective
such
bonds.
Nitrous
ester
serves
as
both
radical
source
hydrogen
atom
transfer
(HAT)
reagent
to
functionalize
utilize
two
carbon
atoms
bond.
The
alkoxy
captures
from
or
N-hydroxyl
induce
1,3-oxygen
migration,
which
is
crucial
subsequent
molecular
authors
report
achieve
bonds
by
participation
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(30), P. 6396 - 6401
Published: July 24, 2024
Spirocyclobutyl
oxindoles
have
garnered
substantial
attention
in
drug
discovery
and
pharmaceuticals
owing
to
their
wide
range
of
biological
activities.
Strain-release
small-ring
compounds
is
a
powerful
strategy
enable
efficient
access
complex
molecules.
In
this
study,
we
successfully
realized
photoredox-catalyzed
strain-release
radical
spirocyclization
approach
attain
functionalized
spirocyclobutyl
oxindoles.
A
diverse
array
radicals,
such
as
sulfonyl,
phosphonyl,
trifluoromethyl,
were
added
efficiently
the
strained
C-C
σ-bond
bicyclobutanes
(BCBs)
afford
library
Furthermore,
obtained
products
could
be
transformed
into
valuable
building
blocks.
The
observed
reactivity
selectivity
been
rationalized
based
on
density
functional
theory
calculations.
A
photochemical
radical
cascade
cyclization
reaction
of
isocyanides
with
α-carbonyl
bromides
under
mild
conditions
is
disclosed
for
accessing
1,4-dibenzodiazepines,
demonstrating
good
tolerance
towards
various
functional
groups.
Organic Letters,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 15, 2025
Radical-initiated
functionalization
of
bicyclo[1.1.0]butanes
(BCBs)
is
a
straightforward
approach
to
accessing
diverse
cyclobutane
derivatives.
However,
selective
C(sp3)–H
at
the
C2
position
BCBs
remains
scarce.
Herein,
mild
protocol
for
hydrogen-evolution
phosphorylation
with
enabled
by
photoinduced
cobaloxime
catalysis
was
realized
in
regio-
and
diastereoselective
manner.
This
oxidant-
additional
photocatalyst-free
method
wide
range
diarylphosphine
oxides.
The
mechanism
studied
via
control
experiments
DFT
calculation.
Moreover,
efficiency
this
highlighted
synthesis
high-value,
structurally
complex
molecules.
Organic Letters,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 22, 2025
A
mild
and
atom-economical
reaction
for
the
Sc(OTf)3-catalyzed
1,3-hydroxyheteroarylation
of
bicyclo[1.1.0]butanes
(BCBs)
with
azaaryl
N-oxides
via
an
unprecedented
[4π+2σ]
cycloaddition/ring-opening
process
is
described.
This
transformation
provides
a
novel
strategy
highly
regio-
diastereoselective
preparation
azaheterocycle-tethered
1,1,3,3-tetrasubstituted
cyclobutane
derivatives
offers
broad
substrate
scope
high
yields.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(40), P. 8503 - 8508
Published: Oct. 1, 2024
The
sustainable
construction
of
spirocyclic
compounds
is
important
to
the
scientific
community
and
pharmaceutical
industries.
Herein,
we
demonstrate
a
carbamoyl
radical-initiated
intramolecular
dearomative
spirocyclization
access
spiro-cyclohexadiene
oxindoles
under
visible
light
irradiation,
which
constitutes
first
example
accessing
I-substituted
derivatives
that
facilitate
diversified
transformations.
Additionally,
scalability,
late-stage
modification
drugs,
significant
antitumor
activity
products
novel
synthesis
platform
for
expediting
drug
development.
Chemical Communications,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Jan. 1, 2024
Bicyclo[1.1.0]butanes
(BCBs)
are
attractive
compounds
for
their
beautiful
"butterfly"
conformations,
distinctive
properties,
and
novel
reactivities.
As
soon
as
the
first
example
had
been
synthesized,
a
wide
range
of
strain-release
reactions
were
explored
preparation
cyclobutanes
bicyclic
systems
in
ground
state
or
excited
state.
In
particular,
with
demand
construction
rigid
three-dimensional
aliphatic
skeletons
to
"escape
from
flatland"
drug
discovery
programs,
numerous
efforts
have
devoted
this
area
expanding
boundaries
reactivities
broadening
chemical
space
bioisosteric
products.
recent
years,
great
resurgence
dramatic
evolution
photochemistry,
photochemical
generally
relying
on
single
electron
transfer
(SET)
energy
(EnT)
strategies
can
provide
much
more
opportunities
capability
innovative
transformations
BCBs.
review,
we
summarize
highlight
advances
(year
>
2016)
topic
hope
that
it
will
inspire
wonderful
chemistry
