Advanced Synthesis & Catalysis,
Journal Year:
2023,
Volume and Issue:
365(24), P. 4538 - 4543
Published: Sept. 5, 2023
Abstract
An
efficient
and
highly
selective
semi‐hydrogenation
of
terminal
alkynes
to
alkenes
using
neutral
dimeric
rhodium(I)
complexes
the
type
[Rh(
μ
‐Cl)(PP)]
2
is
presented.
Dehydroisophytol
(DIP)
was
chosen
as
alkyne
for
this
study
because
its
high
importance
in
industrial
production
synthetic
vitamin
E.
Excellent
selectivity
over
91%
towards
alkene
achieved
with
known
new
rhodium
catalysts.
No
deactivation
observed
molar
Rh:DIP
ratio
could
be
increased
1:20
000,
importantly,
no
reduction
observed.
The
results
presented
open
door
application
homogeneous
alkynes.
Chemistry - A European Journal,
Journal Year:
2024,
Volume and Issue:
30(22)
Published: Feb. 7, 2024
Abstract
Systematic
modification
of
the
chelating
NHC‐phosphine
ligand
(NHC
=
N
‐heterocyclic
carbene)
in
highly
efficient
ketone
hydrogenation
Mn(I)
catalyst
fac
‐[(Ph
2
PCH
NHC)Mn(CO)
3
Br]
has
been
performed
and
catalytic
activity
resulting
complexes
was
evaluated
using
acetophenone
as
a
benchmark
substrate.
While
variation
phosphine
NHC
moieties
led
to
inferior
results
than
for
parent
system,
incorporation
phenyl
substituent
into
methylene
bridge
improved
performance
by
ca
.
times
providing
maximal
TON
values
range
15000–20000.
Mechanistic
investigation
combining
experimental
computational
studies
allowed
rationalize
this
beneficial
effect
an
enhanced
stabilization
reaction
intermediates
including
anionic
hydride
species
PC(Ph)NHC)Mn(CO)
H]
−
playing
crucial
role
process.
These
highlight
interest
such
carbon
substitution
strategy
being
rarely
employed
design
chemically
non‐innocent
ligands.
Organometallics,
Journal Year:
2023,
Volume and Issue:
42(18), P. 2426 - 2446
Published: Sept. 8, 2023
Currently,
the
development
of
environmentally
benign
and
effective
catalytic
reactions
for
organic
synthesis
based
on
low-cost
abundant
metals
is
one
central
research
goals
in
modern
chemistry.
This
review
covers
advancements
homogeneously
catalyzed
using
pincer
complexes
manganese,
iron,
cobalt
featuring
aryl
pyridine
backbones.
Specifically,
C–C
coupling
hydrogenation
alkenes,
alkynes,
aldehydes,
ketones,
esters,
nitriles,
CO2,
carbamates,
ureas,
cyclic
imides
azo
compounds
are
described,
including
their
scope
mechanistic
insights.
Overall,
this
emphasizes
that
combination
inexpensive
readily
available
metals,
such
as
Mn,
Fe,
Co,
with
ligands
capable
ligand–metal
cooperation
may
lead
to
creation
innovative,
versatile,
catalysts,
some
which
can
even
exceed
activity
state-of-the-art
noble-metal
systems
green
chemistry
processes.
Molecules,
Journal Year:
2025,
Volume and Issue:
30(6), P. 1331 - 1331
Published: March 16, 2025
Bulky
NCN
aryl-diamides
featuring
methyl
groups
in
the
benzyl
positions
were
synthesized
with
aim
of
creating
a
new
class
meta-xylene-based
trianionic
pincer
ligands
where
common
decomposition
pathway
metal
complexes
via
C-H
activation
is
prevented.
Sterically
demanding
substituents
on
furthermore
provide
steric
protection
centre
and
can
help
prevent
dimerization
complexes.
While
double
deprotonation
formation
dilithium
salt
was
straightforward,
difficulties
encountered
when
attempting
to
deprotonate
ipso-CH
proton
central
aryl
ring
yield
ligands.
This
stands
contrast
related
without
benzylic
positions.
Experimental
theoretical
investigations
led
conclusion
that
challenges
third
are
likely
caused
by
an
interplay
increased
electron
density
at
nitrogen
atoms
hindrance.
Both
effects
originate
introduction
positions,
which
make
targeted
less
accessible.
These
results
further
insight
into
impact
both
electronic
properties
ligands,
may
find
utility
coordination
chemistry
applications
metalation
be
achieved
direct
rather
than
requiring
triple
deprotonation.
Nature Communications,
Journal Year:
2025,
Volume and Issue:
16(1)
Published: May 12, 2025
Abstract
The
development
of
catalysts
that
are
based
on
earth-abundant
metals
remains
a
grand
challenge.
Alloy
nanocrystals
(NCs)
form
an
emerging
class
heterogeneous
catalysts,
offering
the
promise
small,
uniform
with
composition-control.
Here,
we
report
synthesis
small
Ni
and
bimetallic
Ni-X
(X=
Zn,
Ga,
In)
NCs
for
alkyne
semihydrogenation
catalysis.
We
show
3
Zn
particularly
reactive
selective
under
mild
reaction
conditions
at
low
loadings.
While
all
more
than
pure
NCs,
Ni-Zn
also
maintain
excellent
reactivity
compared
to
Ni-Ga
Ni-In
alloys.
Ab-initio
calculations
can
explain
differences
in
reactivity,
indicating
that,
unlike
Ga
In,
atoms
interact
substrates.
further
robust
tolerate
broad
range
substrates,
which
may
be
linked
favorable
amine-terminated
surface.
ACS Catalysis,
Journal Year:
2023,
Volume and Issue:
13(21), P. 14012 - 14022
Published: Oct. 17, 2023
Two
bench-stable
Fe(II)
alkyl
complexes
[Fe(κ3PCP-PCP-iPr)(CO)2(R)]
(R
=
CH2CH2CH3,
CH3)
were
obtained
by
the
treatment
of
[Fe(κ3PCP-PCP-iPr)(CO)2(H)]
with
NaNH2
and
subsequent
addition
CH3CH2CH2Br
CH3I,
respectively.
The
reaction
proceeds
via
anionic
Fe(0)
intermediate
Na[Fe(κ3PCP-PCP-iPr)(CO)2].
catalytic
performance
both
was
investigated
for
transfer
hydrogenation
terminal
internal
alkynes
utilizing
PhSiH3
iPrOH
as
a
hydrogen
source.
Precatalyst
activation
is
initiated
migration
ligand
to
carbonyl
C
atom
an
adjacent
CO
ligand.
In
agreement
previous
findings,
rate
follows
order
nPr
>
Me.
Accordingly,
[Fe(κ3PCP-PCP-iPr)(CO)2(CH2CH2CH3)]
more
active
catalyst.
takes
place
at
25
°C
catalyst
loading
0.5
mol%.
There
no
overhydrogenation,
in
case
alkynes,
exclusively,
Z-alkenes
are
formed.
implemented
protocol
tolerates
variety
electron-donating
electron-withdrawing
functional
groups
including
halides,
nitriles,
unprotected
amines,
heterocycles.
Mechanistic
investigations
deuterium
labeling
studies
DFT
calculations
undertaken
provide
reasonable
mechanism.
Dalton Transactions,
Journal Year:
2024,
Volume and Issue:
53(8), P. 3484 - 3489
Published: Jan. 1, 2024
A
bench
stable
iron(
ii
)
complex
with
the
pincer
ligand
backbone
was
synthesized
and
characterized.
The
well-defined
iron
successfully
utilized
for
dehydrogenation
of
DMAB
subsequent
transfer
semi-hydrogenation
terminal
alkynes.
Chemical Reviews,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 25, 2025
Alkenes
constitute
a
significant
class
of
chemical
compounds
with
applications
in
the
bulk,
pharmaceutical,
or
perfume
industry.
Among
known
methods
olefin
production,
semihydrogenation
C-C
triple
bond
seems
to
be
most
straightforward
one.
Nonetheless,
success
this
reaction
requires
full
control
over
diastereoselectivity,
eradication
parasitic
process
over-reduction
migration
double
formed,
and
achieving
satisfactory
functional-group
compatibility.
The
review
demonstrates
developments
field
alkyne
period
2010-2022,
selected
papers
published
2023
2024,
emphasizing
solutions
above-mentioned
limitations.
We
discuss
mechanistic
aspects
transformation,
including
those
related
unconventional
systems.
includes
examples
organic
synthesis,
confirming
considerable
utility
process.
Finally,
strategies
enhance
catalyst
selectivity
are
summarized.
For
reader's
convenience,
we
provided
graphical
guidebook
catalytic
systems,
illustrating
efficiency
particular
method.
ChemCatChem,
Journal Year:
2023,
Volume and Issue:
15(20)
Published: Sept. 1, 2023
Abstract
The
widespread
use
of
pyridine‐based
PNP
pincer
ligands
has
inspired
the
concept
metal‐ligand
cooperation
(MLC),
in
which
reactivity
at
deprotonated
CH
2
(or
NH)
arm
ligand
is
proposed
to
play
an
important
role.
Several
groups
developed
a
family
PNP‐type
with
methylated
arms
were
initially
introduced
test
effect
blocking
MLC
catalysis,
but
eventually
led
unexpected
consequences
such
as
stabilization
unusual
oxidation
states,
beneficial
catalytic
activity,
or
selectivity.
Analysis
sterics
imposed
by
introducing
Me
revealed
that
protection
can
be
efficient
tool
control
around
metal
alternative
phosphine
substitution,
leading
much
greater
steric
hinderance
above
and
below
pincer's
coordination
plane.
This
Concept
will
describe
several
illustrative
examples
contrast
classical
/NH‐arm
pincers
their
CMe
/NMe‐armed
counterparts,
particular
related
Ru‐catalyzed
alcohol
dehydrogenative
coupling,
Fe‐catalyzed
hydrogenation,
hydroboration,
alkyne
semihydrogenation.
Dalton Transactions,
Journal Year:
2024,
Volume and Issue:
53(12), P. 5580 - 5591
Published: Jan. 1, 2024
This
manuscript
describes
the
synthesis
and
Mn
I
complexes
of
triazolyl-pyridine-based
phosphine
ligand
their
catalytic
utility
in
quinoline
derivatives
transfer
hydrogenation
aldehydes
ketones.