Higher
amines
are
important
high-valuable
chemicals
with
wide
applications,
and
amination
of
alcohols
is
a
green
route
to
them,
which
however
generally
suffers
from
harsh
reaction
conditions
use
equivalent
base.
Herein,
we
report
an
ionic-liquid
(IL)
hydrogen-bonding
promoted
dihydrogen
autotransfer
strategy
for
higher
over
cobalt
catalyst
under
base-free
conditions.
Co(BF4
)2
⋅
6
H2
O
complexed
triphos
IL
(e.
g.,
tetrabutylphosphonium
tetrafluoroborate,
[P4444
][BF4
])
shows
high
performances
the
tolerant
scope
alcohols,
affording
in
good
excellent
yields.
Mechanism
investigation
indicates
that
[BF4
]-
anion
activates
alcohol
via
hydrogen
bonding,
promoting
transfer
both
hydroxyl
H
α-H
atoms
form
aldehyde
intermediate
dihydride
complex,
involved
subsequent
reductive
amination.
This
provides
effective
amination,
may
have
promising
applications
alcohol-involved
alkylation
reactions.
Abstract
Dehydrogenative
coupling
(DC)
and
borrowing
hydrogen(ation)
(BH)
reactions
are
crucial
in
modern
organic
synthesis,
offering
efficient
sustainable
ways
to
create
valuable
compounds.
However,
they
often
face
a
significant
challenge:
the
alkoxide
trap.
This
Concept
explores
trap
DC
BH
reactions,
starting
with
basic
mechanisms
role
of
intermediates.
It
then
examines
how
leads
catalyst
deactivation
reduced
selectivity,
influenced
by
thermodynamic
kinetic
factors.
To
address
this,
we
review
recent
advances
design,
ligand
engineering,
optimized
reaction
conditions,
along
use
in‐situ
spectroscopy
computational
modelling,
better
understand
underlying
processes
guide
rational
development.
Furthermore,
this
highlights
broad
applicability
DC,
across
various
substrates,
underscoring
urgency
addressing
issue
unlock
their
full
synthetic
potential.
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(16), С. 11161 - 11172
Опубликована: Июль 31, 2024
A
sustainable
catalytic
synthesis
of
selective
monoalkylated
amines
from
nitroarenes
and
alcohols
by
new
palladium(II)-NNO
pincer-type
complexes
has
been
described.
Herein,
a
series
Pd(II)
[Pd(NNO)PPh
Abstract
A
low‐valent
tungsten
catalyzed
carbonylative
Sonogashira
coupling
reactions
has
been
established.
The
present
protocol
utilizes
inexpensive
and
readily
available
W(CO)
6
as
precatalyst
proceeds
in
the
presence
of
atmospheric
CO,
providing
a
practical
method
to
series
functionalized
alkynones
indoxyls
compounds
under
mild
reaction
conditions.
Moreover,
simple
system,
good
functional
group
tolerance
broad
substrate
scope
enable
application
this
transformation
synthesis
carbonyl‐containing
molecules.
Catalysts,
Год журнала:
2022,
Номер
12(11), С. 1458 - 1458
Опубликована: Ноя. 17, 2022
A
new
N-heterocyclic
carbene
(NHC)
copper(I)
complex
supported
on
graphene
oxide
(GO-NHC-Cu)
was
synthesised
and
thoroughly
characterised
by
various
instrumental
techniques
such
as
FT-IR,
FT-Raman,
PXRD,
XPS,
FESEM,
EDX,
HRTEM,
TGA
ICP-OES.
The
catalytic
activity
of
the
explored
in
N-alkylation
anilines
with
alcohols
under
solvent-free
aerobic
conditions
to
afford
monoalkylated
products
good
excellent
yields
(20
products,
83–96%).
All
were
isolated
1H
13C{1H}
NMR
spectroscopy.
catalyst
recuperated
from
reaction
mixture
simple
filtration
reused
for
up
five
successive
cycles
insignificant
loss
activity.
control
experiments
showed
that
proceeded
conditions.
green
chemistry
metrics
found
be
fairly
close
ideal
values:
carbon
efficiency
(95.9%),
E-factor
(0.15),
atom
economy
(92.14%),
process
mass
intensity
(1.15)
(86.80%).
air
stability,
selectivity,
recyclability
catalyst,
high
are
some
salient
features
reported
methodology.
Higher
amines
are
important
high-valuable
chemicals
with
wide
applications,
and
amination
of
alcohols
is
a
green
route
to
them,
which
however
generally
suffers
from
harsh
reaction
conditions
use
equivalent
base.
Herein,
we
report
an
ionic-liquid
(IL)
hydrogen-bonding
promoted
dihydrogen
autotransfer
strategy
for
higher
over
cobalt
catalyst
under
base-free
conditions.
Co(BF4
)2
⋅
6
H2
O
complexed
triphos
IL
(e.
g.,
tetrabutylphosphonium
tetrafluoroborate,
[P4444
][BF4
])
shows
high
performances
the
tolerant
scope
alcohols,
affording
in
good
excellent
yields.
Mechanism
investigation
indicates
that
[BF4
]-
anion
activates
alcohol
via
hydrogen
bonding,
promoting
transfer
both
hydroxyl
H
α-H
atoms
form
aldehyde
intermediate
dihydride
complex,
involved
subsequent
reductive
amination.
This
provides
effective
amination,
may
have
promising
applications
alcohol-involved
alkylation
reactions.
