The Journal of Organic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 4, 2025
1,3-Imidazole-4,5-dicarboxylic
acid
derivatives
were
investigated
with
respect
to
the
properties
of
underlying
N-heterocyclic
carbenes.
Their
selenium
adducts
prepared
as
diesters,
monoesters,
and
dianionic
dicarboxylates.
Se-methylation
yielded
selenenyls
(cationic
selenoethers).
77Se
NMR
shifts
are
considered
a
measure
electronic
carbene.
Since
they
very
sensitive
external
(solvent,
pH,
temperature,
reference
reagent,
method)
internal
parameters
(substituent
effects,
steric
nonclassical
H-bonding,
anisotropy),
difficulties
can
arise
in
reliably
interpreting
these
values.
Our
model
compounds
allow
systematic
investigation
influence
charges
on
since
both
structural
changes
measurement
conditions
have
been
minimized.
Depending
charge,
cover
range
from
42.1
ppm
(dianionic
dicarboxylate)
via
65.0
(monoanionic
92.5
(neutral
diester)
153.8
selenoether)
DMSO-d6.
The
signals
also
show
considerable
solvent
pH
dependence,
which
was
selection
solvents
(MeOD,
CDCl3,
CD2Cl2,
CD3COOD,
CD3CN,
acetone-d6,
THF-d8,
pyridine-d5,
toluene-d8,
DMSO-d6)
values
D2O.
Linear
relationships
found
between
HOMO
LUMO
energies
shifts,
respectively.
Chinese Journal of Chemistry,
Год журнала:
2020,
Номер
38(10), С. 1167 - 1202
Опубликована: Май 10, 2020
N
‐Heterocyclic
carbene
(NHC)
organocatalysis
has
been
developed
as
an
important
approach
in
modern
organic
synthesis.
Versatile
activation
modes
within
NHC
have
established
with
countless
transformations
being
realized
both
efficient
and
selective
fashion.
We
would
like
to
provide
overview
on
the
key
progresses
achieved
this
field
past
two
decades.
Since
numerous
excellent
reviews
documented
area,
we
will
mainly
focus
scientific
development
of
research
based
basic
reaction
typical
intermediates.
ACS Sustainable Chemistry & Engineering,
Год журнала:
2020,
Номер
8(35), С. 13362 - 13368
Опубликована: Авг. 11, 2020
The
use
of
1,3-dimethylimidazolium-2-carboxylate
as
an
organocatalyst
for
the
glycolysis
waste
PET,
poly(ethylene
terephthalate),
is
reported
first
time.
Postconsumer
PET
was
completely
depolymerized
in
less
than
1
h
at
180
°C
with
up
to
60%
bis(2-hydroxyethyl
terephthalate)
(BHET)
recovered
by
precipitation
after
cooling
reaction
mixture.
Under
comparable
conditions,
basic
ionic
liquid,
1,3-dimethylimidazolium
acetate,
a
significantly
effective
catalyst
suggesting
that
catalysis
occurs
through
formation
nucleophilic
N-heterocyclic
carbene.
JACS Au,
Год журнала:
2021,
Номер
2(1), С. 22 - 57
Опубликована: Дек. 15, 2021
Mesoionic
carbenes
(MICs)
of
the
1,2,3-triazolylidene
type
have
established
themselves
as
a
popular
class
compounds
over
past
decade.
Primary
reasons
for
this
popularity
are
their
modular
synthesis
and
strong
donor
properties.
While
such
MICs
mostly
been
used
in
combination
with
transition
metals,
few
years
also
seen
utility
together
main
group
elements.
In
paper,
we
present
an
overview
recent
developments
on
that
include,
among
others,
(i)
cationic
anionic
MIC
ligands,
(ii)
donor/acceptor
properties
these
ligands
focus
several
methods
known
estimating
properties,
(iii)
detailed
3d
metal
complexes
(iv)
results
redox
photophysical
based
(v)
electrocatalysis,
redox-switchable
catalysis,
small-molecule
activation
to
highlight
applications
contemporary
chemistry.
By
discussing
aspects
from
synthetic,
spectroscopic,
application
point
view
classes
compounds,
state
art
containing
perspective
future
research
field.
Journal of the American Chemical Society,
Год журнала:
2019,
Номер
141(37), С. 14576 - 14580
Опубликована: Сен. 3, 2019
The
synthesis
of
stable
heavier
analogues
nitriles
as
monomeric
tetrylene-phosphinidenes
MesTerEP(IDipp)
(E
=
Ge,
Sn;
MesTer
2,6-Mes2C6H3,
IDipp
C([N-(2,6-iPr2C6H4)CH]2)
was
achieved
by
taking
advantage
NHC
(N-heterocyclic
carbene,
here
IDipp)
coordination
to
the
low-valent
phosphorus
center.
Multiple
bonding
character
E-P
bonds
examined
experimentally
and
computationally.
Both
germanium
tin
compounds
undergo
[2+2]
cycloaddition
with
diphenylketene,
whereas
reaction
derivative
tris(pentafluorophenyl)borane
provided
unique
"push-pull"
phosphastannene
(MesTer)(Ar)Sn
P(IDipp)
(Ar
C6F4[B(F)(C6F5)2]).
Going
further,
we
demonstrated
potential
tetrylene-phosphinidene
complexes
in
catalytic
hydroboration
carbonyl
compounds.
Angewandte Chemie International Edition,
Год журнала:
2019,
Номер
59(14), С. 5782 - 5787
Опубликована: Дек. 21, 2019
We
report
a
new
class
of
stable
mesoionic
N-heterocyclic
olefins,
featuring
highly
polarized
(strongly
ylidic)
double
bond.
The
ground-state
structure
cannot
be
described
through
an
uncharged
mesomeric
Lewis-structure,
thereby
structurally
distinguishing
them
from
traditional
olefins
(NHOs).
mNHOs
can
easily
obtained
deprotonation
the
corresponding
methylated
N,N'-diaryl-1,2,3-triazolium
and
N,N'-diaryl-imidazolium
salts,
respectively.
In
their
reactivity,
they
represent
strong
σ-donor
ligands
as
shown
by
coordination
complexes
rhodium
boron.
Their
calculated
proton
affinities,
experimentally
derived
basicities
(competition
experiments),
well
donor
abilities
(Tolman
electronic
parameter;
TEP)
exceed
so
far
reported
NHOs.
Chemical Society Reviews,
Год журнала:
2024,
Номер
53(12), С. 6150 - 6243
Опубликована: Янв. 1, 2024
We
have
compiled
the
recent
progress
of
low-valent
group-14
compounds
in
catalysis,
polymerization,
small
molecule
activation,
thin
film
deposition,
photophysical
properties,
and
medicinal
properties.
