Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(24), P. 5069 - 5073
Published: June 7, 2024
We
have
demonstrated
a
Pd(0)-catalyzed
Heck/C(sp3)–H
activation
cascade
for
the
synthesis
of
spirocyclopropyl
oxindoles
in
high
yields
from
easily
accessible
ortho-bromoacrylamides.
The
formation
oxindole
is
guided
by
an
unconventional
four-membered
palladacycle
through
C(sp3)–H
activation.
reaction
exhibits
wide
range
substrate
scope
and
operates
efficiently
with
mere
0.5
mol
%
Pd-catalyst.
In
addition,
use
microwave
conditions
facilitates
rapid
completion
reaction.
Furthermore,
this
spirocyclopropanation
strategy
can
be
coupled
[3
+
2]
cycloaddition
to
produce
spiropyrrolidine
oxindoles,
offering
valuable
approach
preparation
alkaloids
such
as
(±)-horsfiline
(±)-coerulescine.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(31), P. 21239 - 21244
Published: July 25, 2024
Peripheral
functionalization
of
a
quaternary
carbon
via
C(sp3)–H
bond
activation
has
made
significant
progress
in
recent
years.
However,
direct
editing
through
Csp3–Csp3
cleavage
and
refunctionalization
nonstrained
acyclic
molecules
remain
underexploited.
Herein
we
report
reaction
which
methyl
group
attached
to
is
shifted
its
neighboring
secondary
with
concurrent
oxidation
the
C–C
single
C═C
double
bond.
Specifically,
morpholinyl
amide
2,2-dimethyl
alkanoic
acids
converted
2-methylene-3-methyl
acid
derivatives
presence
catalytic
amount
palladium
acetate,
Selectfluor
sodium
carbonate.
Control
experiments
suggest
that
proceeds
sequence
selective
group,
resulting
C(sp3)–PdII
PdIV
intermediate
followed
by
unprecedented
1,3-PdIV
migration,
1,2-methyl/PdIV
dyotropic
rearrangement
finally,
β–Hydride
elimination.
In
this
domino
process,
migrates
successively
from
primary
finally
carbon,
leading
primary,
secondary,
carbon.
Organic Letters,
Journal Year:
2022,
Volume and Issue:
24(21), P. 3781 - 3785
Published: May 20, 2022
1,4-Palladium
migration
has
emerged
as
a
reliable
method
for
directed
C–H
functionalization.
In
contrast
to
coupling
with
carbon
nucleophiles,
limited
examples
heteroatom
nucleophiles
have
been
reported.
Herein
we
report
palladium-catalyzed
intermolecular
C(sp3)–H
phosphorylation
reaction
via
1,4-palladium
migration,
which
is
often
difficult
because
of
the
strong
coordination
phosphorus
reagents
palladium
catalysts.
Phosphorylation
bonds
accomplished
in
good
yields
excellent
regioselectivity.
The
judicious
selection
phosphine
ligand
proved
be
key
success
this
cascade
process.
Cell Reports Physical Science,
Journal Year:
2022,
Volume and Issue:
3(3), P. 100776 - 100776
Published: Feb. 16, 2022
The
formation
of
thermodynamically
accessible
metallacycle
is
crucial
to
achieve
site-selective
C–H
bond
activation.
Here,
we
report
an
isocyanide-bridging
activation
through
the
a
five-membered
palladacycle.
As
such,
proximal
in
aldehyde
moiety
activated
selectively.
subsequent
palladium
shift
and
intramolecular
C=N
insertion
construct
valuable
isoindolinone
framework.
Compared
with
conventional
isocyanide-promoted
activation,
both
carbon
nitrogen
atoms
isocyanide
are
engaged
new
formations.
Notably,
three
types
isoindolinones
can
be
obtained
selectively
by
variations
reaction
conditions.
Mechanistic
studies
shed
light
on
pathways.
Moreover,
synthetic
potential
current
methodology
demonstrated
providing
concise
routes
key
intermediates
indoprofen,
indobufen,
aristolactams,
lennoxamine,
falipamil.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(24), P. 5069 - 5073
Published: June 7, 2024
We
have
demonstrated
a
Pd(0)-catalyzed
Heck/C(sp3)–H
activation
cascade
for
the
synthesis
of
spirocyclopropyl
oxindoles
in
high
yields
from
easily
accessible
ortho-bromoacrylamides.
The
formation
oxindole
is
guided
by
an
unconventional
four-membered
palladacycle
through
C(sp3)–H
activation.
reaction
exhibits
wide
range
substrate
scope
and
operates
efficiently
with
mere
0.5
mol
%
Pd-catalyst.
In
addition,
use
microwave
conditions
facilitates
rapid
completion
reaction.
Furthermore,
this
spirocyclopropanation
strategy
can
be
coupled
[3
+
2]
cycloaddition
to
produce
spiropyrrolidine
oxindoles,
offering
valuable
approach
preparation
alkaloids
such
as
(±)-horsfiline
(±)-coerulescine.
