Abstract
This
review
describes
the
main
advances
in
enantioselective
fluorination
over
last
decade,
while
also
recalling
early
developments
this
area.
Three
strategies
have
been
employed
to
achieve
concomitant
introduction
of
a
fluorine
atom
by
C(sp3)—F
bond
formation
with
stereocon-trol
at
same
carbon
center:
(1)
use
chiral
fluorinating
agents,
(2)
diverse
organocatalytic
approaches,
and
(3)
transition-metal-catalyzed
fluorinations.
These
complementary
ap-ply
both
electrophilic
nucleophilic
The Chemical Record,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 17, 2024
Abstract
As
a
significant
variant
of
the
Michael
reaction,
1,6‐addition
reaction
has
undergone
considerable
development
over
past
decade.
This
effective
strategy
enables
synthesis
variety
novel
and
potentially
bioactive
functional
molecules.
In
this
review,
we
summarize
recent
progress
in
NHC‐catalyzed
reactions,
highlighting
their
efficiency
rapid
complex
We
also
provide
our
perspectives
on
future
dynamic
highly
active
research
area.
Abstract
A
facile
and
practical
one‐pot
synthesis
of
hydrobenzoin
has
been
developed
from
the
readily
available
aromatic
aldehydes,
under
NHC
catalysis.
Basically,
present
research
elucidates
a
novel,
sustainable
approach
for
hydrobenzoin,
capitalizing
on
catalytic
prowess
N‐heterocyclic
carbene
(NHC)
utilizing
sodium
borohydride
(NaBH
4
)
as
an
effective
reducing
partner
in
this
conversion.
By
harnessing
unique
reactivity
NHCs,
methodology
enables
efficient
formation
C−C
bonds,
leading
to
streamlined
with
high
yields
while
tolerating
various
functional
groups.
Furthermore,
system
offers
notable
advantages
terms
atom
economy,
mild
reaction
conditions,
operational
simplicity,
making
it
promising
strategy
chemical
synthesis.
The
detailed
mechanistic
insights
provided
herein
shed
light
underlying
pathways,
facilitating
deeper
understanding
mechanism.
Overall,
study
underscores
significant
potential
catalysis
versatile
tool
valuable
organic
compounds,
thereby
contributing
advancement
green
chemistry
principles
pursuit
environmentally
benign
processes.
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.
Abstract
This
review
describes
the
main
advances
in
enantioselective
fluorination
over
last
decade,
while
also
recalling
early
developments
this
area.
Three
strategies
have
been
employed
to
achieve
concomitant
introduction
of
a
fluorine
atom
by
C(sp3)—F
bond
formation
with
stereocon-trol
at
same
carbon
center:
(1)
use
chiral
fluorinating
agents,
(2)
diverse
organocatalytic
approaches,
and
(3)
transition-metal-catalyzed
fluorinations.
These
complementary
ap-ply
both
electrophilic
nucleophilic
