Advanced Synthesis & Catalysis,
Journal Year:
2023,
Volume and Issue:
365(21), P. 3597 - 3602
Published: Sept. 7, 2023
Abstract
Cross‐electrophilic
coupling
of
various
benzyl
sulfonium
salts
with
C
allyl
−O
electrophiles
is
described
using
a
simple
Co−Mn
catalytic
system.
This
system
able
to
activate
both
the
stable
sp
3
−S
bond
and
allylic
acetate
or
ether
under
mild
reaction
conditions
form
functionalized
alkyl
olefinic
compounds.
Allyl
methyl
ethers
were
employed
for
first
time
in
transition
metal‐catalyzed
cross‐electrophilic
build
−C
bonds.
Preliminary
mechanistic
studies
suggested
involvement
radicals
generated
from
C−S
cleavage
through
single
electron
transfer.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(34), P. 19049 - 19059
Published: Aug. 17, 2023
Given
the
importance
and
beneficial
characteristics
of
decorated
azetidines
in
medicinal
chemistry,
efficient
strategies
for
their
synthesis
are
highly
sought
after.
Herein,
we
report
a
facile
elusive
all-carbon
quaternary-center-bearing
azetidines.
By
adopting
well-orchestrated
polar-radical
relay
strategy,
ring
strain
release
bench-stable
benzoylated
1-azabicyclo[1.1.0]butane
(ABB)
can
be
harnessed
nickel-catalyzed
Suzuki
Csp2-Csp3
cross-coupling
with
commercially
available
boronic
acids
broad
scope
(>50
examples),
excellent
functional
group
tolerance,
gram-scale
utility.
Preliminary
mechanistic
studies
provided
insights
into
underlying
mechanism,
wherein
opening
ABB
catalytic
quantity
bromide
accounts
conversion
redox-active
azetidine,
which
subsequently
engages
reaction
through
radical
pathway.
The
synergistic
nickel
catalysis
could
intriguingly
derived
from
single
source
(NiBr2).
Application
method
to
modify
natural
products,
biologically
relevant
molecules,
pharmaceuticals
has
been
successfully
achieved
as
well
melanocortin-1
receptor
(MC-1R)
agonist
vesicular
acetylcholine
transporter
(VAChT)
inhibitor
analogues
bioisosteric
replacements
piperidine
azetidine
moieties,
highlighting
potential
drug
optimization
studies.
Aside
azetidines,
demonstrate
ancillary
utility
our
system
toward
restricted
tertiary
alkyl
bromides
aryl
construct
quaternary
centers.
Beilstein Journal of Organic Chemistry,
Journal Year:
2024,
Volume and Issue:
20, P. 346 - 378
Published: Feb. 21, 2024
Due
to
their
ease
of
preparation,
stability,
and
diverse
reactivity,
N
-hydroxyphthalimide
(NHPI)
esters
have
found
many
applications
as
radical
precursors.
Mechanistically,
NHPI
undergo
a
reductive
decarboxylative
fragmentation
provide
substrate
capable
engaging
in
transformations.
Their
reduction
via
single-electron
transfer
(SET)
can
occur
under
thermal,
photochemical,
or
electrochemical
conditions
be
influenced
by
number
factors,
including
the
nature
electron
donor,
use
Brønsted
Lewis
acids,
possibility
forming
charge-transfer
complexes.
Such
versatility
creates
opportunities
influence
reaction
conditions,
providing
parameters
with
which
control
reactivity.
In
this
perspective,
we
an
overview
different
mechanisms
for
reactions
involving
esters,
emphasis
on
recent
additions,
cyclizations
cross-coupling
reactions.
Within
these
classes,
discuss
utility
eye
towards
continued
development
complexity-generating
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
14(14), P. 11087 - 11100
Published: July 9, 2024
Fluoroalkyl
fragments
have
played
a
critical
role
in
the
design
of
pharmaceutical
and
agrochemical
molecules
recent
years
due
to
enhanced
biological
properties
fluorinated
compared
their
non-fluorinated
analogues.
Despite
potential
advantages
conferred
by
incorporating
difluoromethyl
group
organic
compounds,
industrial
adoption
difluoromethylation
methods
lags
behind
fluorination
trifluoromethylation.
This
is
part
challenges
applying
common
sources
towards
applications.
We
report
here
nickel-catalyzed
cross-electrophile
coupling
(hetero)aryl
bromides
with
2-pyridyl
sulfone,
sustainably
sourced,
crystalline
reagent.
The
scope
this
reaction
demonstrated
24
examples
(67
±
16%
average
yield)
including
diverse
array
heteroaryl
precursors
difluoromethyl-containing
preclinical
pharmaceuticals.
can
be
applied
small-scale
parallel
synthesis
benchtop
scale-up
under
mild
conditions.
As
sulfone
reagents
are
uncommon
electrophiles
coupling,
mechanism
process
was
investigated.
Studies
confirmed
formation
•CF2H
instead
difluorocarbene.
A
series
modified
sulfones
revealed
that
reactivity
does
not
correlate
exclusively
reduction
coordination
cations
or
nickel
pyridyl
essential
reactivity,
setting
out
parameters
for
matching
coupling.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(15), P. 2674 - 2679
Published: April 11, 2023
The
construction
of
all-carbon
quaternary
centers
in
small-ring
systems
is
important
but
challenging
organic
synthesis.
Herein,
by
taking
gem-difluorocyclopropyl
bromides
(DFCBs)
as
a
type
general
and
versatile
building
block,
we
developed
practical
method
for
gem-difluorinated
cyclopropanes
(DFCs).
reaction
relies
on
the
involvement
radical
intermediate,
which
can
couple
with
wide
range
nucleophiles
under
copper
catalysis.
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: May 27, 2024
Abstract
Herein,
we
disclose
a
highly
efficient
cobalt-catalyzed
cross-electrophile
alkynylation
of
broad
range
unactivated
chlorosilanes
with
alkynyl
sulfides
as
stable
and
practical
electrophiles.
Strategically,
employing
easily
synthesized
precursors
allows
access
to
various
alkynylsilanes
in
good
excellent
yields.
Notably,
this
method
avoids
the
utilization
strong
bases,
noble
metal
catalysts,
high
temperature
forcing
reaction
conditions,
thus
presenting
apparent
advantages,
such
substrate
scope
(72
examples,
up
97%
yield),
Csp-S
chemo-selectivity
functional
group
compatibility
(Ar-X,
X
=
Cl,
Br,
I,
OTf,
OTs).
Moreover,
utilities
are
also
illustrated
by
downstream
transformations
late-stage
modification
structurally
complex
natural
products
pharmaceuticals.
Mechanistic
studies
elucidated
that
cobalt
catalyst
initially
reacted
sulfides,
activation
occurred
via
an
S
N
2
process
instead
radical
pathway.
Journal of the American Chemical Society,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 21, 2025
Herein,
we
present
a
novel
class
of
diazo
compounds
as
atomic
carbon
reagents
substituted
with
two
orthogonal
redox-active
leaving
groups
that
were
exploited
in
the
late-stage
construction
chiral
centers
aryl
C–H
bonds
from
aromatic
feedstocks
and
drug
molecules.
Key
to
strategy
was
use
photoredox
catalysis
enable
an
initial
diazomethylation
reaction
able
generate
diazomethyl-substituted
esters.
Subsequent
readily
available
starting
materials
proceeded
using
broad
range
well-known
ester
functionalizations.
Moreover,
applicability
our
reagent
tested
automated
parallel
synthesis
library
Fenofibrate
derivatives.
