Organometallics,
Journal Year:
2023,
Volume and Issue:
42(22), P. 3227 - 3235
Published: Nov. 8, 2023
Density
functional
theory
has
been
applied
in
a
mechanistic
study
of
the
role
pincer
complex
PdII(NCN–N,C,N)(O2CPh-O)
([NCN]-
=
[2,6-(Me2NCH2)2C6H3]−)
(3)
Heck-type
catalysis
presence
diphenyliodine(III)
triflate
as
oxidative
arylating
agent
for
CH2═CHAr
and
bicarbonate
base
to
afford
PhCH═CHAr
(Ar
p-BrC6H4).
The
initially
formed
palladium(IV)
PhPd(NCN–N,C,N)(OBz···HOCO2–O,O)
(9)
(ΔG‡
31.6
kcal/mol)
undergoes
Ph···Cipso
reductive
elimination
form
PdII{NC(Ph)N–N,C,N}(OBz···HOCO2–O,O)
(11)
25.6
kcal/mol),
which
is
reduced
by
palladium(0)
species.
Reduction
Pd0
occurs
via
deprotonation
one
NMe2
group
provide
"–CH2–N(Me)–CH2–PdII″
moiety
23.6
followed
nucleophilic
attack
on
this
give
product
with
"–CH2–NMe(CH2OCO2H)″
14.5
kcal/mol).
exceptionally
facile
addition
Ph2I(HCO3)
5.1
Modeling
[Pd(benzene)(O2CPh)]−
provides
similar
result
5.6
allowing
entry
PhPdII
species
be
able
undergo
migratory
insertion
CH2═CAr
14.4
β-hydride
16.2
processes
Pd0/PdII
catalysis.
Activation
barriers
reduction
PdIV
Pd0,
process,
are
lower
than
initial
oxidation
species,
ensuring
that
only
small
quantity
PdII(NCN)(OBz)
consumed,
accord
its
completion
Computational
studies
PdIV-mediated
revealed
energetically
unfavorable
preference
formation
CH2═C(Ar)Ph
rather
experimentally
reported
PhCH═CHAr.
This
reveals
precatalyst,
PdII
elimination,
reducing
extremely
diaryliodine(III)
reagent
selectivity
differences
centers.
Inorganic Chemistry,
Journal Year:
2023,
Volume and Issue:
62(49), P. 20129 - 20141
Published: Nov. 23, 2023
An
efficient
synthesis
of
two
pincer
preligands
[Ph2PCH(R)ImCH2CH2CH2PPh3]X2
(R
=
H,
X
OTf;
R
Ph,
BF4)
was
developed.
Subsequent
reactions
with
PdCl2
and
an
excess
Cs2CO3
led
to
the
formation
highly
stable
cationic
ortho-metalated
Pd(II)
complexes
[(P,C,C,C)Pd]X
exhibiting
phosphine,
NHC,
phosphonium
ylide,
σ-aryl
donor
extremities.
The
protonation
one
latter
H
affords
complex
[(P,C,C)Pd(MeCN)](OTf)2
bearing
unprecedented
nonsymmetrical
NHC
core
scaffold
a
5,6-chelating
framework.
overall
properties
this
phosphine-NHC-phosphonium
ylide
ligand
were
estimated
using
experimental
νCN
stretching
frequency
in
corresponding
[(P,C,C)Pd(CNtBu](OTf)2
derivative
shown
be
competitive
related
bis(NHC)-phosphonium
phenoxy-NHC-phosphonium
pincers.
presence
phenyl
substituent
bridge
between
phosphine
moieties
[(P,C,C,C)Pd](BF4)
makes
possible
deprotonation
position
LDA
provide
persistent
zwitterionic
[(P,C,C,C)Pd]
featuring
rare
P-coordinated
moiety
addition
conventional
C-coordinated
one.
comparison
31P
13C
NMR
data
for
these
C-
P-bound
fragments
within
same
molecule
performed
first
time,
bonding
situation
both
cases
studied
detail
by
QTAIM
ELF
topological
analyses.
Chemical Communications,
Journal Year:
2023,
Volume and Issue:
59(47), P. 7151 - 7165
Published: Jan. 1, 2023
One
of
the
ultimate
goals
chemistry
is
to
understand
and
manipulate
chemical
reactions,
which
implies
ability
monitor
reaction
its
underlying
mechanism
at
an
atomic
scale.
Israel Journal of Chemistry,
Journal Year:
2023,
Volume and Issue:
63(7-8)
Published: July 28, 2023
Abstract
Pincer
ligand
complexes,
which
appeared
nearly
five
decades
ago,
have
provided
a
valuable
platform
for
the
study
of
fundamental
chemical
processes
and
development
efficient
catalysts
many
transformations.
These
complexes
usually
contained
transition
metal
atoms
or
ions,
their
respective
pincer
ligands
often
featured
phosphine
donor
groups,
strongly
coordinate
to
center
allow
its
steric
electronic
properties
be
fine‐tuned.
The
increasing
need
develop
cost‐effective
sustainable
catalytic
has
driven
search
main‐group
metals
as
alternatives
commonly‐used
metals.
In
this
review,
we
show
that
despite
inherent
mismatch
between
phosphines,
are
soft
Lewis
bases,
hard
acids,
series
well‐defined
phosphine‐based
containing
Li(I),
Na(I),
K(I),
Mg(II),
Ca(II),
Zn(II)
Al(III)
been
reported,
proven
active
industrially‐relevant
European Journal of Inorganic Chemistry,
Journal Year:
2023,
Volume and Issue:
26(31)
Published: Aug. 29, 2023
Abstract
Synthesis,
characterization
and
catalytic
activity
of
cyclometalated
iridium
complexes
with
a
bidentate
POC
ligand
is
presented.
Metalation
POC‐H
(di‐
tert
‐butyl(phenoxy)phosphane)
[Ir(COD)Cl]
2
proceeded
rapidly
at
room
temperature
afforded
mixture
(POC)(POC‐H)IrHCl
(
1
)
(POC)(COD)IrHCl
b
),
from
which
(POC)(L)IrHCl
where
L=PPh
3
c
bipyridine
d
[2,2′‐bipyridine]‐6,6′‐diol
e
were
prepared
through
exchange.
The
compounds
tested
in
acceptorless
dehydrogenation
1‐phenylethanol
transfer
ethanol
context
comparison
pincer
counterparts
(POCOP)IrHCl
(PCN)IrHCl.
An
attempt
to
prepare
dihydride
complex
led
dimeric
[(POC)(bipy‐diol−)IrH]
that
could
explain
the
low
.
DFT
studies
provided
insight
into
vs
POCOP‐H
metalation
mechanism.
ChemCatChem,
Journal Year:
2024,
Volume and Issue:
16(12)
Published: Feb. 26, 2024
Abstract
A
novel
phosphine‐free
ruthenium
pincer
complex
based
on
an
NNN
ligand
has
been
prepared
and
fully
characterized.
The
was
subsequently
employed
as
efficient
catalyst
for
the
N‐methylation
of
amines
direct
nitroarenes
using
methanol
a
C1
source
under
mild
reaction
conditions
following
borrowing‐hydrogen
approach.
Both
catalytic
transformations
were
performed
with
only
amounts
base
closed
air
without
any
other
additives.
Inorganics,
Journal Year:
2024,
Volume and Issue:
12(8), P. 221 - 221
Published: Aug. 15, 2024
C–H
bond
activation
is
a
crucial
synthetic
strategy
widely
utilized
in
both
academic
and
industrial
settings.
Due
to
the
strong
kinetically
inert
nature
of
bond,
its
functionalization
typically
requires
metal-based
catalysts.
This
review
highlights
most
significant
advancements
homogeneously
catalyzed
reactions
using
pincer
complexes
with
metals
from
groups
8–10,
capable
promoting
challenging
activation,
published
since
2010.
In
particular,
it
focuses
on
for
borylation,
isomerization,
dehydrogenation,
among
other
processes,
discussing
their
scope
mechanistic
insights.
