Coinage
metal
complexes,
particularly
Cu(I)
and
Au(I),
supported
by
N-heterocyclic
carbenes
are
of
broad
interest
in
organometallic
synthesis,
catalysis,
luminescent
materials.
The
d10
coinage
metals
can
adopt
varied
linear,
trigonal
planar,
tetrahedral
geometries.
However,
two-coordinate,
linear
Au(I)
complexes
sterically
demanding
monodentate
or
chelating
generally
observed.
In
most
cases,
ligands
generate
multinuclear
species
with
geometries
at
the
corresponding
centers
rather
than
mononuclear
complexes.
this
report,
we
synthesized
two
bis(carbene)
anchored
a
flexible
bipyridine
rigid
naphthyridine
backbone
tunable
proximal
distal
steric
properties
wingtips
to
examine
influence
rigidity
directionality
carbene
donors
on
formation
planar
species.
bipyridine-bis(carbene)
(ImPy)2
ligand
exclusively
stabilizes
dinuclear
chloride
Ag(I),
whereas
naphthyridine-bis(carbene)
(NBC)
mononuclear,
Ag(I)
complex.
The Journal of Physical Chemistry A,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 5, 2025
A
theoretical
study
on
the
mechanism,
regioselectivity,
and
enantioselectivity
of
NHC-catalyzed
dearomatizing
annulation
benzoxazoles
with
enals
has
been
conducted
using
density
functional
theory
calculations.
Our
calculated
results
indicate
that
favored
mechanism
occurs
through
eight
reaction
steps:
initial
binding
NHC
to
enals,
followed
by
formation
Breslow
intermediate
via
proton
transfer.
Subsequent
oxidation
generates
α,β-unsaturated
acylazolium
intermediate,
which
can
undergo
Michael
addition
benzoxazoles.
Sequential
protonation/deprotonation/cyclization
produces
six-membered
cyclic
undergoes
catalyst
elimination,
leading
final
product.
DABCO·H+
was
found
play
important
roles
in
transfer
cyclization.
Without
DABCO·H+,
energy
barrier
up
44.2
kcal/mol
for
step
2
is
too
high
be
accessible.
With
corresponding
value
lowered
18.6
kcal/mol.
The
cyclization
7.4
DABCO·H+.
determines
both
regioselectivity.
According
NCI
analysis,
controlled
strong
interactions
(such
as
C-H···O,
C-H···N,
π···π)
between
We
also
discuss
solvent
substituent
effects
role
NHC.
mechanistic
insights
obtained
present
would
help
improving
current
systems
or
designing
new
synthetic
routes.
Dalton Transactions,
Год журнала:
2024,
Номер
53(30), С. 12503 - 12518
Опубликована: Янв. 1, 2024
Nickel
and
palladium
NHC
complexes
with
fluorine
substituents
have
been
synthesized.
Their
electronic
parameters,
including
σ-donation
π-acceptance,
were
evaluated,
considering
the
position
number
of
substituents.
Inorganics,
Год журнала:
2023,
Номер
11(10), С. 385 - 385
Опубликована: Сен. 27, 2023
Five
silver(I)
complexes,
namely
chloro[1-methallyl-3-benzyl)benzimidazol-2-ylidene]
silver
(6),
chloro[1-methallyl-3-(2,3,5,6-tetramethylbenzyl)benzimidazol-2-ylidene]silver
(7),
chloro[1-methallyl-3-(3,4,5-trimethoxylbenzyl)benzimidazol-2-ylidene]silver
(8),
chloro[1-methallyl-
3-(naphthylmethyl)benzimidazol-2-ylidene]silver
(9),
and
chloro
[1-methallyl-3-(anthracen-9-yl-
methyl)benzimidazol-2-ylidene]silver
(10),
were
prepared
starting
from
their
corresponding
benzimidazolium
salts
oxide
in
71–81%
yields.
A
single-crystal
X-ray
structure
of
7
was
determined.
These
five
Ag-NHC
complexes
evaluated
for
antimicrobial
biofilm
formation
inhibition
properties.
Complex
10
exhibited
high
activities
comparable
to
those
obtained
with
standard
drugs
such
as
Fluconazole
contact
Staphylococcus
aureus,
Enterococcus
faecalis,
Escherichia
coli,
Acinetobacter
baumannii,
Candida
albicans.
The
latter
complex
has
been
shown
be
very
efficient
antibiofilm
activity,
92.9%
at
1.9
μg/mL
on
coli.
Additionally,
the
molecules
optimized
DFT-based
computational
methods
obtaining
insight
into
structure/reactivity
relations
through
relative
energies
frontier
orbitals.
also
analyzed
by
molecular
docking
method
against
DNA
gyrase
coli
CYP51
Hydration
reactions
consist
of
the
introduction
a
molecule
water
into
chemical
compound.
This
process
is
particularly
useful
method
to
allow,
for
instance,
conversion
alkynes
carbonyls,
which
are
strategic
intermediates
in
synthesis
plethora
compounds.
Herein
we
demonstrate
that
L-cysteine
can
catalyse
hydration
activated
very
effective
and
fully
regioselective
manner
access
β-ketosulfones,
amides
esters
aqueous
conditions.
The
mild
reaction
conditions
facilitated
integration
with
enzyme
catalysis
chiral
β-hydroxy
sulfones
from
corresponding
one-pot
cascade
good
yields
excellent
enantiomeric
excess.
These
findings
pave
way
towards
establishing
general
metal-free,
cost-effective,
more
sustainable
alkyne
processes
Molecular Catalysis,
Год журнала:
2024,
Номер
559, С. 114055 - 114055
Опубликована: Март 22, 2024
Au-catalyzed
N,O-functionalization
of
1,4-diyn-3-ols
with
N-hydroxyanilines
provides
a
short
and
efficient
approach
to
construct
versatile
pyrrole
frameworks.
Using
DFT
calculations,
we
systematically
investigated
the
detailed
mechanisms
involved
in
this
reaction.
It
was
found
that,
commonly
asserted
NH/OH
activation
mechanism
unfavoured
due
high
energy
barrier.
The
main
reason
believed
be
associated
inversion
configuration
on
sp3-hybrid
C
atom
(generated
after
H(N)-shift)
which
results
significant
consumption
for
subsequent
H(O)-shift.
Therefore,
here
present
unique
"1,4-elimination/1,4-syn-protodeauration"
catalytic
mechanism,
(i)
charge
delocalization
carbon
cation
is
conductive
stability
1,4-elimination
TS;
(ii)
exergonicity
decreases
potential
surface
reaction;
(iii)
sp2-C
site
ensures
energy-efficient
retention
during
1,4-syn-protodeauration,
contrast
energy-consuming
classical
anti-protodeauration.
