Angewandte Chemie,
Год журнала:
2024,
Номер
unknown
Опубликована: Ноя. 14, 2024
Abstract
Cyclobutanes
are
prominent
structural
components
in
natural
products
and
drug
molecules.
With
the
advent
of
strain‐release‐driven
synthesis,
ring‐opening
reactions
bicyclo[1.1.0]butanes
(BCBs)
provide
an
attractive
pathway
to
construct
these
three‐dimensional
structures.
However,
stereoselective
difunctionalization
central
C−C
σ‐bonds
remains
challenging.
Reported
herein
is
a
covalent‐based
organocatalytic
strategy
that
exploits
radical
NHC
catalysis
achieve
diastereoselective
acylfluoroalkylation
BCBs
under
mild
conditions.
The
Breslow
enolate
acts
as
single
electron
donor
provides
NHC‐bound
ketyl
with
appropriate
steric
hindrance,
which
effectively
distinguishes
between
two
faces
transient
cyclobutyl
radicals.
This
operationally
simple
method
tolerates
various
fluoroalkyl
reagents
common
functional
groups,
providing
straightforward
access
polysubstituted
cyclobutanes
(75
examples,
up
>19
:
1
d.r.).
combined
experimental
theoretical
investigations
this
system
confirm
formation
NHC‐derived
understanding
how
radical‐radical
coupling
occurs.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(32), С. 22829 - 22839
Опубликована: Авг. 1, 2024
The
molecular
editing
of
ketones
represents
an
appealing
strategy
due
to
its
ability
maximize
the
structural
diversity
ketone
compounds
in
a
straightforward
manner.
However,
developing
efficient
methods
for
arbitrary
modification
ketonic
molecules,
particularly
those
integrated
within
complex
skeletons,
remains
significant
challenge.
Herein,
we
present
unique
recasting
that
involves
radical
acylation
Advanced Synthesis & Catalysis,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 23, 2025
Abstract
Imidazolium‐dithiocarboxylate
zwitterions
(NHC
⋅
CS
2
),
a
novel
organocatalyst
that
derived
from
N‐heterocyclic
carbene
(NHC),
was
used
to
activate
cyclopropenones.
Under
the
catalysis
of
10
mol%
NHC
2,
range
phenols,
alcohols,
primary
and
secondary
amines
react
with
cyclopropenones
produce
trisubstituted
α
,
β
‐unsaturated
esters
amides
in
46–95%
yield.
More
than
68
products,
including
7
natural
product
derivatives
have
been
synthesized
through
this
method.
Mechanism
study
showed
act
as
Lewis
base
C=C
double
bond
trigger
ring‐opening
reaction.
HRMS
analysis
indicated
formation
key
adduct
cyclopropenone.
importantly,
demonstrated
completely
different
catalytic
activity
catalysts,
latter
one
cannot
catalyse
these
reactions.
Advanced Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 13, 2025
Abstract
Isoflavonoids
represent
a
privileged
scaffold
among
various
bioactive
natural
products,
rendering
their
structural
diversification
through
green
synthesis
and
subsequent
biological
evaluations
compelling
research
area.
In
this
study,
an
NHC
organocatalytic
radical
acylalkylation
of
1,3‐enynes
using
salicylaldehydes
is
presented,
followed
by
cascade
intramolecular
annulation,
yielding
series
fluorinated
isoflavone
derivatives
with
substantial
yields
under
environmental‐friendly
conditions.
This
approach,
distinguished
its
excellent
modularity
high
functional
group
tolerance,
represents
unprecedented
1,3,4‐trifunctionalization
designed
for
the
isoflavones
in
single
step.
Furthermore,
it
demonstrated
that
these
synthesized
isoflavonoids
effectively
suppress
proliferation
breast
cancer
cells,
most
potent
compound
8
also
inhibiting
migration
MDA‐MB‐231
cells.
A
metal-free,
visible-light-induced
NHC-catalyzed
multiple-component
reaction
involving
aldehydes
and
aryl
thianthrenium
salts
for
the
carboacylation
of
alkenes
is
reported.
In
this
reaction,
NHC-activated
afforded
Breslow
intermediates,
which
reduced
generated
radicals.
The
resulting
radicals
underwent
radical
addition
reactions
to
yield
arylacylation
products,
in
presence
iodoalkane,
participated
halogen
atom
transfer
process
generate
alkyl
facilitate
olefin
alkylacylation.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Ноя. 14, 2024
Cyclobutanes
are
prominent
structural
components
in
natural
products
and
drug
molecules.
With
the
advent
of
strain-release-driven
synthesis,
ring-opening
reactions
bicyclo[1.1.0]butanes
(BCBs)
provide
an
attractive
pathway
to
construct
these
three-dimensional
structures.
However,
stereoselective
difunctionalization
central
C-C
σ-bonds
remains
challenging.
Reported
herein
is
a
covalent-based
organocatalytic
strategy
that
exploits
radical
NHC
catalysis
achieve
diastereoselective
acylfluoroalkylation
BCBs
under
mild
conditions.
The
Breslow
enolate
acts
as
single
electron
donor
provides
NHC-bound
ketyl
with
appropriate
steric
hindrance,
which
effectively
distinguishes
between
two
faces
transient
cyclobutyl
radicals.
This
operationally
simple
method
tolerates
various
fluoroalkyl
reagents
common
functional
groups,
providing
straightforward
access
polysubstituted
cyclobutanes
(75
examples,
up
>19
:
1
d.r.).
combined
experimental
theoretical
investigations
this
system
confirm
formation
NHC-derived
understanding
how
radical-radical
coupling
occurs.
Organic Chemistry Frontiers,
Год журнала:
2024,
Номер
11(21), С. 6243 - 6264
Опубликована: Янв. 1, 2024
Combination
of
N-heterocyclic
carbene
catalysis
and
photocatalysis
with
radical
process
is
a
powerful
strategy
to
access
useful
molecules.
In
this
review,
we
summarized
recent
advances
in
growing
area
from
the
perspective
reaction
mechanism.
