Advanced Synthesis & Catalysis,
Год журнала:
2024,
Номер
366(17), С. 3616 - 3623
Опубликована: Июнь 20, 2024
Abstract
A
three‐component
allylic
alkylation
reaction
of
α‐diazo
ketones,
water
and
allyl
carbonate
under
the
cooperative
catalysis
Rh
2
(OAc)
4
,
Pd
(dba)
3
Brønsted
acid
was
disclosed.
This
method
provides
an
expeditious
access
to
α‐keto
homoallylic
alcohols
in
good
high
yields.
Controlled
experiments
support
that
transformations
proceed
through
cross‐interception
two
active
intermediates
Pd‐allyl
species
enol
derived
from
oxonium
ylides.
Moreover,
synthetic
generated
products
enable
creation
motifs
enriched
with
dense
functional
groups,
underscoring
their
potential
as
valuable
building
blocks.
Abstract
Multicomponent
reactions
provide
an
excellent
approach
toward
quaternary
carbon
centres
utilizing
convergent
chemical
in
a
highly
selective
manner
under
one‐pot
conditions.
The
reactivity
of
substrates
and
metal
catalysts
is
carefully
controlled,
precluding
the
formation
side‐products.
In
this
context,
transition
catalyzed
onium
ylides
generated
via
diazo
precursors
nucleophiles
with
third
component
(an
electrophile)
have
garnered
significant
attention.
Using
allylic
precursor
as
electrophilic
partner
provides
opportunities
to
construct
all‐carbon
centres.
Furthermore,
presence
allyl
fragment
multicomponent
product
serves
pivotal
handle
for
carrying
out
subsequent
modifications.
Several
recent
studies
employed
Rh,
Pd,
dual
Rh/Pd
catalytic
systems
involving
alkylation
that
proceed
synergistic
or
relay
pathway.
Although
not
significantly
successful,
few
cases,
asymmetric
induction
achieved
through
chiral
phosphoric
acids
phosphine
ligands.
Limited
substrate
catalyst
scope
underlying
mechanistic
complexities
posed
formidable
challenges,
slowing
advancement
reactions.
This
review
details
using
readily
available
like
compounds,
carbonates,
(R‐OH,
R‐NH
2
,
etc
.)
forming
complex
organic
compounds.
Our
primary
objective
discuss
issues
may
facilitate
progress
field.
Organic Letters,
Год журнала:
2022,
Номер
24(23), С. 4160 - 4164
Опубликована: Июнь 3, 2022
We
describe
a
Xantphos-containing
dinuclear
palladium
complex-enabled
geminal
aminoallylation
of
diazocarbonyl
compounds,
which
selectively
provides
range
quaternary
α-amino
esters.
Direct
N–H
insertion,
allylic
alkylation
amino
nucleophiles,
and
diene
formation
were
not
observed
under
standard
conditions.
Mechanistic
studies
indicated
that
relayed
pathway
via
allylation
the
insertion
product
or
[2,3]-sigmatropic
rearrangement
an
ylide
intermediate
was
unlikely.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(5), С. 2801 - 2808
Опубликована: Фев. 17, 2023
A
simple
method
for
the
preparation
of
imidazo[4,5-b]indole-2-thiones
from
2-alkynylnitrobenzenes
and
thioureas
is
described.
In
reaction,
a
Wittig-like
process
was
triggered
by
PPh3
followed
cyclization
step.
The
products
were
afforded
in
yields
70–98%
under
mild
conditions.
Additionally,
stable
could
be
prepared
via
coupling
European Journal of Organic Chemistry,
Год журнала:
2022,
Номер
2022(26)
Опубликована: Май 24, 2022
Abstract
The
efficient
construction
of
quaternary
carbon
centers
is
a
challenging
task
due
to
their
enhanced
structural
complexity.
Although
the
catalytic
gem‐
difunctionalization
α
‐diazo
carbonyl
compounds
via
metal‐carbenoids
well‐documented,
developing
new
methods
access
which
are
difficult
or
unattainable
in
monocatalysis
highly
desirable.
Dual
catalysis
where
two
different
catalysts
work
concurrently
has
emerged
as
powerful
strategy
achieve
reactivity
and
selectivity.
In
this
review,
we
highlight
recent
advances
cooperative
Rh(II)/Pd(0)
dual
for
centers,
focusing
on
synthetic
utility
stable
‐diazo‐
β
‐keto‐esters
allylic
carboxylates.
Additionally,
several
asymmetric
dual‐catalyzed
transformations
generating
chiral
also
discussed.
Abstract
This
review
aims
to
collect
and
analyze
recent
results
with
respect
the
use
of
varied
palladium
preparations
in
synthesis
five‐membered
nitrogen
heterocycles
including
condensed
derivatives.
Results
have
been
selected
focus
on
studies
last
three
years.
Furthermore,
a
common
feature
all
methods
treated
here
is
that
nitrogen‐containing
ring
formed
via
closing
appropriate
starting
materials.
Selected
examples
discussed
will
reveal
plethora
products
from
small
monocycles
multi‐ring
systems
can
be
successfully
accessed.
Major
features
are
wide
product
ranges,
high
yields
stereoselectivities
often
achieved
under
mild
reaction
conditions.
Advanced Synthesis & Catalysis,
Год журнала:
2024,
Номер
366(11), С. 2596 - 2601
Опубликована: Апрель 9, 2024
Abstract
Under
the
catalysis
of
Rh
2
(OAc)
4
(10
mol%)
and
(±)‐Me‐Pybox
(20
in
1,2‐DCE
at
80
°C,
homocoupling/[4+1]
cycloaddition
cascade
diazobarbiturates
with
diazopyrazolones
proceeded
readily
provided
spirobarbiturates
32–88%
chemical
yields.
The
structure
obtained
was
identified
by
X‐ray
diffraction
analysis.
The Journal of Organic Chemistry,
Год журнала:
2022,
Номер
87(15), С. 10390 - 10397
Опубликована: Июль 26, 2022
An
efficient
and
direct
carbonylation
of
aminoquinoline
benzamides
has
been
developed
using
abundant
inexpensive
Ni(OAc)2·4H2O
as
the
catalyst
carbon
monoxide
a
cost-efficient
C1
building
block.
This
process
features
good
functional-group
tolerance
can
be
conducted
on
gram
scale.
The
directing
group
easily
removed
under
mild
conditions.
