Zeitschrift für anorganische und allgemeine Chemie,
Journal Year:
2021,
Volume and Issue:
647(14), P. 1455 - 1461
Published: April 28, 2021
Abstract
In
this
work,
a
new
Ru(II)
complex
with
the
redox‐active
pincer
2,6‐bis(phenylazo)pyridine
ligand
(L)
is
reported
which
acts
as
metal‐ligand
bifunctional
catalyst
for
transfer
hydrogenation
reactions.
The
isolated
[(L)Ru(PMe
2
Ph)
(CH
3
CN)](ClO
4
)
;
[
1
](ClO
characterized
by
host
of
spectroscopic
measurements
and
X‐ray
structure
determination.
It
diamagnetic
single‐crystal
analysis
reveals
that
]
2+
adopts
distorted
octahedral
geometry
where
L
binds
Ru
center
in
meridional
fashion.
observed
elongation
coordinated
azo
bond
length
(1.29
Å)
attributed
to
extensive
π‐back
bonding,
dπ(Ru
II
)→π*(azo)L.
an
efficient
catalyst,
brings
about
catalytic
reactions
broad
array
aldehydes
ketones
isopropanol
inert
conditions.
selectivity
aldehyde
reduction
over
other
reducible
functional
groups
such
nitro,
nitrile,
ester
etc
was
also
investigated.
Mechanistic
studies,
examined
suitable
control
isotope
labelling
experiments,
indicate
synergistic
participation
both
metal
centres
via
formation
fleeting
Ru−H
intermediate
hydrogen
walking
function
L.
Green Chemistry,
Journal Year:
2020,
Volume and Issue:
22(11), P. 3323 - 3357
Published: Jan. 1, 2020
This
review
describes
the
state-of-the-art
of
metal-catalyzed
selective
transfer
hydrogenation
α,β-unsaturated
aldehydes
and
ketones
to
allylic
alcohols,
covering
literature
last
30
years.
Organometallics,
Journal Year:
2019,
Volume and Issue:
38(16), P. 3218 - 3226
Published: Aug. 14, 2019
The
four
bidentate
manganese(I)
complexes
[(C5H4N-C5H3N-OH)Mn(CO)3Br]
(1),
[(C9H6N-C5H3N-OH)Mn(CO)3Br]
(2),
[(C8H5N2-C5H3N-OH)Mn(CO)3Br]
(3),
and
[(C8H5N2-C5H3N-OCH3)Mn(CO)3Br]
(4)
were
synthesized.
These
tested
as
catalysts
for
the
transfer
hydrogenation
of
ketones,
3
showed
highest
activity.
reactions
proceeded
well
with
0.5
mol
%
catalyst
loading
20
t-BuOK
at
85
°C
24
h.
Furthermore,
was
also
used
a
synthesis
primary
alcohols
via
aldehydes
1,2-disubstituted
benzimidazoles
quinolines
acceptorless
dehydrogenative
condensations.
ACS Catalysis,
Journal Year:
2023,
Volume and Issue:
13(16), P. 10798 - 10823
Published: Aug. 1, 2023
With
the
aim
to
design
water-soluble
organometallic
Ru(II)
complexes
acting
as
anticancer
agents
catalyzing
transfer
hydrogenation
(TH)
reactions
with
biomolecules,
we
have
synthesized
four
monocarbonyl
(1–4),
featuring
1,4-bis(diphenylphosphino)butane
(dppb)
ligand
and
different
bidentate
nitrogen
(N∧N)
ligands,
of
general
formula
[Ru(OAc)CO(dppb)(N∧N)]n
(n
=
+1,
0;
OAc
acetate).
The
compounds
been
characterized
by
methods,
including
1H
31P
NMR
spectroscopies,
electrochemistry,
well
single-crystal
X-ray
diffraction
in
case
1
4.
also
studied
for
their
hydrolysis
an
aqueous
environment
catalytic
regioselective
reduction
nicotinamide
adenine
dinucleotide
(NAD+)
1,4-dihydronicotinamide
(1,4-NADH)
solution
sodium
formate
a
hydride
source.
Moreover,
stoichiometric
oxidation
1,4-NADH
investigated
UV–visible
spectrophotometry
spectroscopy.
results
suggest
that
cycle
can
start
directly
from
intact
compound
or
its
aquo/hydroxo
species
(in
1–3)
afford
ruthenium
complex.
Overall,
initial
structure–activity
relationships
could
be
inferred
which
point
toward
influence
extension
aromatic
N∧N
cationic
1–3
on
TH
both
reduction/oxidation
processes.
While
complex
3
is
most
active
NADH
O2,
neutral
4,
picolinamidate
ligand,
stands
out
catalyst
NAD+,
while
being
completely
inactive
oxidation.
convert
pyruvate
into
lactate
presence
formate,
albeit
scarce
efficiency.
In
any
case,
all
compounds,
intermediates
observed
even
isolated
1–3.
Together,
insights
kinetic
electrochemical
characterization
that,
1–3,
sees
H-transfer
rate-limiting
step,
whereas
NAD+
H-donor,
step
substrate,
suggested
density
functional
theory
(DFT)
calculations.
Compound
stable
respect
solution,
appears
operate
via
mechanism
other
derivatives.
Finally,
activity
ability
form
reactive
oxygen
(ROS)
cancerous
nontumorigenic
cells
vitro.
Noteworthy,
conversion
aldehydes
alcohols
achieved
three
catalysts
living
cells,
assessed
fluorescence
microscopy.
Furthermore,
formation
intermediate
upon
treatment
cancer
cell
extracts
has
detected
this
study
paves
way
application
non-arene-based
biological
environment.
Chemistry - A European Journal,
Journal Year:
2020,
Volume and Issue:
26(27), P. 6050 - 6055
Published: Jan. 27, 2020
Ruthenium
PNP
pincer
complexes
bearing
supplementary
cyclometalated
C,N-bound
ligands
have
been
prepared
and
fully
characterized
for
the
first
time.
By
replacing
CO
H-
as
ancillary
in
such
complexes,
additional
electronic
steric
modifications
of
this
topical
class
catalysts
are
possible.
The
advantages
new
demonstrated
general
α-alkylation
ketones
with
alcohols
following
a
hydrogen
autotransfer
protocol.
Herein,
various
aliphatic
benzylic
were
applied
green
alkylating
agents
aromatic,
heteroaromatic
or
substituents
well
cyclic
ones.
Mechanistic
investigations
revealed
that
during
catalysis,
Ru
carboxylate
predominantly
formed
whereas
neither
nor
CN
ligand
released
from
catalyst
significant
amounts.
Organometallics,
Journal Year:
2020,
Volume and Issue:
39(17), P. 3212 - 3223
Published: Aug. 30, 2020
The
catalytic
utility
of
[RuL1(CO)2I2]
(1),
containing
an
annelated
π-conjugated
imidazo-naphthyridine-based
mesoionic
carbene
(MIC)
ligand
(L1),
is
evaluated
for
E-selective
alkyne
semihydrogenation.
precatalyst
1,
in
combination
with
2
equiv
AgBArF,
semihydrogenates
a
broad
range
internal
alkynes
molecular
hydrogen
(5
bar)
water.
(E)-Alkenes
are
accessed
high
yields,
and
number
reducible
functional
groups
tolerated.
A
chelate
MIC
two
cis
carbonyls
provide
well-defined
platform
at
the
Ru
center
hydrogenation
isomerization.
loss
iodides
presence
render
electron
deficient
thus
formation
metal
vinylidenes
terminal
avoided.
This
leveraged
semihydrogenation
by
same
system
isopropyl
alcohol.
Reaction
profile,
isomerization,
kinetic,
DFT
studies
reveal
initial
to
(Z)-alkene,
which
further
isomerizes
(E)-alkene
via
metal-catalyzed
Z
→
E
Dalton Transactions,
Journal Year:
2019,
Volume and Issue:
48(36), P. 13580 - 13588
Published: Jan. 1, 2019
Novel
air
stable
ruthenium(ii)
complexes
bearing
tridentate
ligands
bis((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)amine
(L1),
1-(1-benzyl-1H-1,2,3-triazol-4-yl)-N-(pyridin-2-ylmethyl)methanamine
(L2)
or
2-(4-phenyl-1H-1,2,3-triazol-1-yl)-N-(pyridin-2-ylmethyl)ethan-1-amine
(L3)
were
synthesised.
The
nitrogen
based
easily
prepared
by
virtue
of
click
chemistry
using
cheap
and
commercially
available
reagents.
ruthenium
obtained
heating
the
Ru(PPh3)3Cl2
precursor
NNN
ligand
in
toluene
under
reflux
for
2
hours,
achieving
yields
82-87%.
These
fully
characterized
means
NMR,
FT-IR
high
resolution
ESI
spectroscopy.
crystal
structure
one
was
determined.
showed
excellent
activity
selectivity
hydrogenation
ketones
aldehydes.
DFT
calculations
show
that
complex
3
may
react
through
an
outer-sphere
catalytic
cycle
rather
than
via
inner-sphere
mechanism.
Dalton Transactions,
Journal Year:
2019,
Volume and Issue:
49(2), P. 453 - 465
Published: Dec. 3, 2019
The
ligand
HCNNOMe
(6-(4-methoxyphenyl)-2-aminomethylpyridine)
is
easily
prepared
from
the
commercially
available
6-(4-methoxyphenyl)pyridine-2-carbaldehyde
by
reaction
of
hydroxylamine
and
hydrogenation
(H2,
1
atm)
with
Pd/C.
pincer
complexes
cis-[RuCl(CNNOMe)(PPh3)2]
(1)
[RuCl(CNNOMe)(PP)]
(PP
=
dppb,
2;
dppf,
3)
are
synthesized
[RuCl2(PPh3)3],
PP
(for
2
in
2-propanol
NEt3
at
reflux
isolated
85-93%
yield.
Carbonylation
(CO,
gives
[RuCl(CNNOMe)(CO)(PPh3)]
(4)
(79%
yield)
which
cleanly
reacts
Na[BArf4]
PCy3,
affording
cationic
trans-[Ru(CNNOMe)(CO)(PCy3)(PPh3)][BArf4]
(5)
(92%
yield).
These
robust
display
remarkably
high
catalytic
activity
transfer
(TH)
lignocellulosic
biomass
carbonyl
compounds,
using
a
basic
medium
(NaOiPr
or
K2CO3).
Thus,
furfural,
5-(hydroxymethyl)furfural
Cyrene
reduced
to
corresponding
alcohols
3,
S/C
range
10
000-100
000,
within
minutes
hours
(TOF
up
500
000
h-1).
monocarbonyl
complex
5
was
found
be
extremely
active
TH
cinnamaldehyde,
vanillin
derivatives
ethyl
levulinate
000-50
000.
Vanillyl
alcohol
also
obtained
(S/C
500)
presence
K2CO3.