Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Ноя. 1, 2024
Asymmetric
de
novo
synthesis
of
benzocyclobutenes
(BCBs)
via
catalytic
intermolecular
reaction
is
highly
desired
for
efficient
access
to
this
important
class
compounds,
yet
such
a
strategy
remains
unmet
challenge.
Here,
we
report
Pd/Pyrox-catalyzed
asymmetric
[2+2]
annulation
between
arylboronic
acids
and
functionalized
alkenes,
providing
an
unprecedented
protocol
various
enantio-enriched
BCBs
in
modular
versatile
manner
under
mild
conditions.
A
broad
substrate
scope
with
excellent
enantioselectivity
has
been
achieved
the
current
protocol.
The
isolation
characterization
key
chiral
palladacycle
intermediate,
together
DFT
calculations,
provides
strong
evidence
pathway
including
enantiodetermining
arylpalladation
step.
Journal of the American Chemical Society,
Год журнала:
2022,
Номер
144(20), С. 8920 - 8926
Опубликована: Май 13, 2022
Benzocyclobutenes
(BCBs)
are
highly
valuable
compounds
in
organic
synthesis,
medicinal
chemistry,
and
materials
science.
However,
catalytic
modular
synthesis
of
functionalized
BCBs
from
easily
accessible
starting
remains
limited.
We
report
herein
an
efficient
diversely
by
a
Pd(II)-catalyzed
formal
[2+2]
annulation
between
arylboronic
acids
alkenes
the
presence
N-fluorobenzenesulfonimide
(NFSI).
An
intermolecular
carbopalladation
followed
palladium
oxidation,
intramolecular
C(sp2)–H
activation
transient
C(sp3)–Pd(IV)
species,
selective
carbon–carbon
(C–C)
bond-forming
reductive
elimination
high-valent
five-membered
palladacycle
is
proposed
to
account
for
reaction
outcome.
Kinetically
competent
oxidation
alkylPd(II)
alkylPd(IV)
species
important
avoid
formation
Heck
adduct.
The
forges
two
C–C
bonds
cyclobutene
core
compatible
with
wide
range
functional
groups.
No
chelating
bidentate
directing
group
alkene
part
needed
this
transformation.
Chemical Science,
Год журнала:
2022,
Номер
13(21), С. 6348 - 6354
Опубликована: Янв. 1, 2022
Readily
available
2-chlorobenzoic
acid
or
ethyl
phenylpropiolate
as
the
C2
insertion
unit.
High
regioselectivity.
Broad
substrate
scope.
Mechanistic
studies.
Journal of the American Chemical Society,
Год журнала:
2022,
Номер
144(37), С. 16749 - 16754
Опубликована: Сен. 9, 2022
Unique
examples
of
aza-Heck-based
C(sp3)–H
functionalization
cascades
are
described.
Under
Pd(0)-catalyzed
conditions,
the
aza-Heck-type
cyclization
N-(pentafluorobenzoyloxy)carbamates
generates
alkyl–Pd(II)
intermediates
that
effect
palladation
en
route
to
cyclopropanes.
Key
factors
control
site
selectivity
cyclopropanation
process
have
been
elucidated
such
selective
access
a
wide
range
ring-
or
spiro-fused
systems
can
be
achieved.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(28), С. 18811 - 18816
Опубликована: Июль 5, 2024
1,4-Palladium
migration
has
been
widely
used
for
the
functionalization
of
remote
C–H
bonds.
However,
this
mechanism
limited
to
aryl
halide
precursors.
This
work
reports
an
unprecedented
Pd0-catalyzed
cyclobutanation
protocol
producing
valuable
fused
cyclobutanes
starting
from
cycloalkenyl
(pseudo)halides.
reaction
takes
place
via
alkenyl-to-alkyl
1,4-Pd
migration,
followed
by
intramolecular
Heck
coupling.
The
method
performs
best
with
cyclohexenyl
precursors,
giving
access
a
variety
substituted
bicyclo[4,2,0]octenes.
Reactants
containing
N-methyl
or
methoxy
group
give
rise
azetidines
oxetanes,
respectively,
same
mechanism.
Kinetic
and
deuterium-labeling
studies
point
rate-limiting
C(sp3)–H
activation
step.
Organic Letters,
Год журнала:
2024,
Номер
26(37), С. 7834 - 7840
Опубликована: Сен. 5, 2024
The
Narasaka-Heck
reaction
is
one
of
the
most
straightforward
methods
for
constructing
pyrroline
derivatives.
Herein,
we
report
a
novel
nickel-catalyzed
three-component
carbonylation
reaction,
which
cleverly
realizes
continuous
construction
C(sp
The Journal of Organic Chemistry,
Год журнала:
2022,
Номер
87(13), С. 8835 - 8840
Опубликована: Июнь 22, 2022
A
novel
strategy
for
the
synthesis
of
1-pyrrolines
based
on
formal
[4
+
1]
annulation
2-alkyl-2H-azirines
with
diazocarbonyl
compounds
has
been
developed.
This
one-pot
approach
includes
Rh(II)-catalyzed
formation
4-alkyl-2-azabuta-1,3-dienes,
followed
by
DBU-promoted
cyclization,
and
features
a
good
substrate
tolerance.
The
containing
an
ester
group
at
C3
were
prepared
in
three-step
procedure
starting
from
5-alkoxyisoxazoles.
cyclization
2-azabutadienes
to
most
likely
proceeds
via
6π
electrocyclization
conjugated
NH-azomethine
ylide.
Organic Letters,
Год журнала:
2023,
Номер
25(28), С. 5361 - 5365
Опубликована: Июль 12, 2023
The
palladium-catalyzed
synthesis
of
bis-heterocyclic
spirocycles
containing
both
pyrroline
and
indoline
motifs
is
reported.
Di-tert-butyldiaziridinone
used
to
functionalize
palladacycles
generated
in
situ
via
domino
Narasaka–Heck/C–H
activation
reactions.
reaction
readily
scalable,
the
spirocyclic
products
can
undergo
deprotection,
reduction,
(3
+
2)
cycloadditions,
highlighting
their
synthetic
utility.
Additionally,
kinetic
isotope
effect
experiments
support
a
turnover-limiting
C–H
functionalization
step
catalytic
cycle.
Advanced Science,
Год журнала:
2024,
Номер
unknown
Опубликована: Июль 5, 2024
A
Pd-catalyzed
enantioselective
aminosilylation
of
alkenes
via
tandem
Aza-Heck/silylation
reaction
under
Pd/Sadphos
catalysis
is
disclosed.
wide
array
oxime
esters
and
silicon
reagents
are
tolerated,
furnishing
the
chiral
pyrrolines
bearing
one
quaternary
or
two
contiguous
stereocenters
in
good
yield
with
high
enantioselectivity.
Not
only
terminal
but
also
tri-substituented
internal
successfully
participate
reaction,
delivering
vicinal
complete
diastereoselectivity
DFT
study
conducted
to
probe
pathway
origin
enantioselectivity,
which
revealed
that
stereoinduction
arises
from
weak
interaction
between
aromatic
ring
substrate
fragment
naphthyl
group
ligand.
