The
optical
absorbance
behavior
of
a
molecule
during
the
reaction
is
yet
to
be
explored
due
deficiency
in
appropriate
theoretical
and
experimental
tools.
In
present
study,
Intrinsic
Reaction
Coordinate
(IRC)
trapping
methodology
implemented
new
approach
capture
electronic
motion
nitrogen
activation
by
heterocyclic
carbenes.
This
technique
acts
as
Handycam
(Molecular
Handycam)
shoot
photographs
electrons
event
chemical
beyond
Born-Oppenheimer
approximation.
use
newly
designed
molecular
analyse
electron
flow
at
frontier
orbitals
adduct
formation
with
carbene
corroborated
that
−N
2
reaction,
operates
σ
−acceptor
π
−donor
where
bonding
back
processes
occur
before
after
transition
state
reaction.
There
significant
time
delay
between
process,
implying
back-bonding
not
simultaneous
for
this
These
findings
ameliorate
DFT-based
designing
carbenes
model
congenial
catalyst
sequestering
atmospheric
its
metamorphosis
ammonia
an
ambient
metal-free
condition.
It
also
brought
light
absorption
may
change
along
path.
Though
nitrogen,
carbene−N
are
non-responsive
visible
light,
evanescent
region
observed
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 17, 2025
Herein,
we
report
the
carbene-like
activity
of
a
nonisolable,
highly
ambiphilic
cyclic
(alkenyl)(amino)carbene
(SMeCAenAC,
3),
which
is
stabilized
as
[(SMeCAenAC)(H)N(SiMe3)2]
(4).
This
protected
form
(4)
stable
in
air
and
moisture.
Compound
4
can
be
used
carbene
source
through
deamination
upon
heating
to
130-140
°C.
Moreover,
density
functional
theory
(DFT)
calculations
indicate
that
SMeCAenAC
has
smallest
singlet-triplet
gap
(37.05
kcal/mol)
narrow
highest
occupied
molecule
orbital
(HOMO)-lowest
unoccupied
molecular
(LUMO)
(3.92
eV)
among
(alkyl)(amino)carbenes
(CAACs).
The
precursor
(3)
synthesized
on
multigram
scale
with
good
yield.
SMeCAenAC-coordinated
copper
complex
showed
excellent
efficiency
catalytic
addition
phenols
electron-deficient
olefins.
study
also
highlights
[SMeCAenAC-H]OTf
for
metal-free
catalysis,
property
uniquely
characteristic
an
carbene,
even
though
formation
free
was
not
achieved.
Bulletin of the Korean Chemical Society,
Год журнала:
2022,
Номер
43(12), С. 1328 - 1341
Опубликована: Сен. 10, 2022
Abstract
The
isolation
of
cyclic(alkyl)(amino)carbenes
(CAACs)
and
N
,
′‐diamidocarbenes
(DACs)
has
opened
up
new
avenues
in
the
field
carbene
chemistry
due
to
their
unique
properties.
CAACs
are
strong
σ‐donors
π‐acceptors,
whereas
DACs
extremely
π‐acceptors.
ambiphilicity
carbenes
can
facilitate
applications
such
as
small
molecule
activation
catalysis.
Since
DACs,
several
ambiphilic
have
been
synthesized,
thereby
advancing
development
chemistry.
This
review
summarizes
most
relevant
findings
on
until
2022.
Chemical Science,
Год журнала:
2023,
Номер
14(19), С. 5079 - 5086
Опубликована: Янв. 1, 2023
Herein,
we
report
the
first
catalytic
methylation
of
primary
amides
using
CO2
as
a
C1
source.
A
bicyclic
(alkyl)(amino)carbene
(BICAAC)
exhibits
dual
role
by
activating
both
amide
and
to
carry
out
this
transformation
which
enables
formation
new
C-N
bond
in
presence
pinacolborane.
This
protocol
was
applicable
wide
range
substrate
scopes,
including
aromatic,
heteroaromatic,
aliphatic
amides.
We
successfully
used
procedure
diversification
drug
bioactive
molecules.
Moreover,
method
explored
for
isotope
labelling
13CO2
few
biologically
important
detailed
study
mechanism
carried
with
help
spectroscopic
studies
DFT
calculations.
Dalton Transactions,
Год журнала:
2022,
Номер
51(38), С. 14452 - 14457
Опубликована: Янв. 1, 2022
The
NHC·borane
chemistry
has
been
majorly
restricted
to
imidazol-2-ylidene
classes
of
carbenes.
In
our
previous
communication,
we
reported
the
synthesis
6-SIDipp·BH3
[6-SIDipp
=
1,3-di(2,6-diisopropylphenyl)
tetrahydropyrimidine-2-ylidene]
and
its
electrophilic
substitution
reaction
with
iodine.
Here,
have
shown
selective
bromination
a
6-SIDipp
stabilized
sp3
B-H
bond.
Treatment
1.2
equivalents
N-bromosuccinamide
gives
mixture
mono-
disubstituted
products
6-SIDipp·BH2Br
(1)
6-SIDipp·BHBr2
(2).
However,
reactions
alkyl
bromides
or
carbon
tetrabromide
resulted
in
selectively.
Exploration
BHCl2
9-BBN
(9-borabicyclo[3.3.1]nonane)
led
mono-6-SIDipp
adducts
3
6a.
Furthermore,
6a
undergoes
ring
expansion
afford
seven-membered
product,
6b,
under
mild
conditions.
Unlike
9-BBN,
bond
HBpin
oxidative
addition
upon
6-SIDipp,
epitomizing
first
example
(7)
insertion
at
NHCs.
analogous
reactivity
HBcat
tetrahydropyrimidinium
salt
B(cat)2
as
counteranion
(8).
Chemistry - A European Journal,
Год журнала:
2024,
Номер
30(62)
Опубликована: Авг. 15, 2024
Abstract
The
synthesis
and
reactivity
of
an
air
water
stable
Bicyclic
(alkyl)(amino)carbene
(BICAAC)
stabilized
phosphenium
cation
(1)
is
reported.
Air
are
rare
in
the
literature.
Compound
1
obtained
by
reaction
BICAAC
with
Ph
2
PCl
THF
followed
anion
exchange
LiOTf.
reduction
oxidation
yielded
corresponding
α‐radical
phosphine
species
(2)
oxide
(3)
respectively.
All
compounds
well
characterized
single
crystal
X‐ray
diffraction
studies.
Lewis
acidity
3
determined
conducting
fluoride
ion
affinity
experiments
using
UV‐Vis
spectrophotometry
multinuclei
NMR
spectroscopy.
Compounds
exhibited
selective
binding
to
but
did
not
interact
other
halides
(Cl
−
Br
).
Quantum
chemical
calculations
were
performed
understand
structure
nature
bonding
interactions
these
compounds,
as
comprehend
specific
over
halide
ions.
The Journal of Organic Chemistry,
Год журнала:
2022,
Номер
87(18), С. 12386 - 12396
Опубликована: Авг. 31, 2022
Organoborane-catalyzed
hydroboration
of
nitriles
provides
N,N-diborylamines,
which
act
as
efficient
synthons
for
the
synthesis
primary
amines
and
secondary
amides.
Known
nitrile
methods
are
dominated
by
metal
catalysis.
Simple
metal-free
using
diborane
[H-B-9-BBN]2
a
catalyst
pinacolborane
turnover
reagent
is
reported.
The
reaction
monomeric
H-B-9-BBN
with
leads
to
hydrido-bridged
diborylimine
intermediate;
subsequent
sequential
double
hydroboration-transborylation
pathway
involving
B-N/B-H
σ
bond
metathesis
proposed.
Inorganic Chemistry,
Год журнала:
2022,
Номер
61(49), С. 19998 - 20007
Опубликована: Дек. 1, 2022
One
of
the
key
steps
in
many
metal
complex-catalyzed
hydroboration
reactions
is
B-H
bond
activation,
which
results
hydride
formation.
Anionic
ligands
that
include
multiple
lone
pairs
electrons,
cooperation
with
a
center,
have
notable
potential
redox-neutral
activation
through
metal-ligand
cooperation.
Herein,
using
an
easily
prepared
NpyridineNimineNpyrrolide
ligand
(L2)-,
series
divalent
NiIIX(NNN)
complexes
were
synthesized,
X
=
bromide
(2),
phenoxide
(3),
thiophenoxide
(4),
2,5-dimethylpyrrolide
(5),
diphenylphosphide
(6),
and
phenyl
(7).
The
characterized
1H
13C
NMR
spectroscopy,
mass
spectrometry,
X-ray
crystallography
employed
as
precatalysts
for
nitrile
dihydroboration.
Superior
activity
phenoxy
derivative
(3)
[vs
thiophenoxy
(4)
or
(7)]
suggests
occurs
at
Ni-X
(vs
Ni-Npyrrolide)
bond.
Furthermore,
stoichiometric
treatment
2-7
showed
no
reaction,
whereas
pinacolborane
(HBpin)
gave
same
Ni-H
complex
2,
3,
5.
Considering
only
5
successfully
catalyzed
dihydroboration,
we
suggest
catalytic
cycle
involves
conventional
inner
sphere
pathway
initiated
by
substrate
insertion
into
Ni-H.
Beilstein Journal of Organic Chemistry,
Год журнала:
2022,
Номер
18, С. 1332 - 1337
Опубликована: Сен. 26, 2022
The
reduction
of
nitriles
to
primary
amines
is
a
useful
transformation
in
organic
synthesis,
however,
it
often
relies
upon
stoichiometric
reagents
or
transition-metal
catalysis.
Herein,
borane-catalysed
hydroboration
give
reported.
Good
yields
(48-95%)
and
chemoselectivity
(e.g.,
ester,
nitro,
sulfone)
were
observed.
DFT
calculations
mechanistic
studies
support
the
proposal
double
B-N/B-H
transborylation
mechanism.
