Organometallics,
Journal Year:
2022,
Volume and Issue:
41(18), P. 2572 - 2579
Published: Sept. 7, 2022
Chemical
oxidation
of
piano-stool
complexes
Cr(CO)3(TripN═NTrip)
(1)
and
Cr(CO)3(TripN═NTrip)Cr(CO)3
(2)
was
investigated,
which
led
to
a
CAArN
cation
(cyc-1+)
17-electron
chromic
radical
(2•+)
upon
one-electron
reactions,
respectively.
The
reactivity
cyc-1+
extensively
investigated.
electrophilicity
enables
form
Lewis
adducts
with
Me3P.
Cyc-1+
can
be
reduced
by
metal
K
neutral
monoradical
cyc-1•
react
p-benzoquinone
produce
diradical
dication
salt
(X).
electronic
properties
2•+
were
investigated
single-crystal
X-ray
diffraction
EPR
spectroscopy,
in
conjunction
DFT
calculations.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(6), P. 3603 - 3608
Published: Jan. 31, 2024
The
first
example
of
a
hitherto-unknown
facet
catalytic
photooxidant
capability
nitrenium
cations
is
reported
herein.
fundamental
limitation
inability
the
traditional
and
nitreniums
to
achieve
excited-state
redox
potential
beyond
+2.0
V
(vs
Ag/AgCl),
primary
requirement
for
powerful
photooxidant,
addressed
in
this
work
by
developing
structurally
unique
class
N-fused
cations,
with
required
structural
engineering
involving
extensive
π-conjugation
through
ring
fusion
at
site,
which
enabled
significant
lowering
LUMO
energy
easy
reduction
excited
state
(excited-state
up
+2.5
vs
facilitated
effective
delocalization/stabilization
generated
radical.
This
finding
opens
new
way
discover
novel
useful
(photo)catalytic
properties
just
Lewis
acidity.
Organic Letters,
Journal Year:
2022,
Volume and Issue:
24(25), P. 4598 - 4602
Published: June 16, 2022
N-Heterocyclic
nitrenium
(NHN)
salts,
the
analogues
of
N-heterocyclic
carbenes,
have
attracted
considerable
interest.
However,
relatively
little
is
known
about
their
catalytic
ability
beyond
Lewis
acid
catalysis.
Herein,
we
describe
that
NHNs
can
serve
as
electron
acceptors
for
charge
transfer
complex
photoactivations.
We
showcase
that,
under
blue
light
irradiation,
NHN
salts
could
catalyze
generation
aryl
radicals
from
halides.
ACS Catalysis,
Journal Year:
2022,
Volume and Issue:
12(12), P. 6831 - 6839
Published: May 25, 2022
Nitrogen
Lewis
acids
(NLAs)
are
emerging
as
a
powerful
tool
in
strong
bond
activation
and
catalysis.
Till
now,
N,N-dialkyl-nitrenium
salts
were
known
utilized
chemical
transformations.
In
this
article,
we
report
on
the
synthesis
characterization
of
next
generation
nitrenium-based
acids─N,N-diaryl-substituted
naphthotriazinium
salts─,which
opens
door
to
libraries
stereoelectronically
modifiable
catalysts.
We
exemplify
potency
these
acidic
catalysts
gram-scale
hydrosilylation
various
ketimines
aldimines
yields
up
99%
catalyst
loading
low
0.1
mol
%.
Notably,
dialkyl-nitrenium
proved
inefficient
reaction.
Based
our
experimental
theoretical
studies,
elucidated
mechanistic
action
nitrenium
such
reduction-type
reactions,
demonstrating
unique
hydridic
behavior
N–H
bonds
triazanes.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(33), P. 6189 - 6194
Published: Aug. 14, 2023
N-Heterocyclic
nitreniums
(NHNs)
have
been
utilized
as
Lewis
acid
catalysts
to
activate
substrates
with
lone
pairs.
Alternative
their
conventional
applications,
we
discovered
that
NHNs
can
also
serve
charge
transfer
complex
catalysts.
Herein,
present
another
potential
of
by
utilizing
a
weak
interaction
between
and
CF3SO2Cl.
The
method
promotes
CF3SO2Cl
undergo
photohomolysis,
resulting
in
the
CF3
radical.
Mechanistic
studies
suggested
could
be
due
π-hole
effect
NHNs.
Synthesis,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Sept. 19, 2024
Abstract
N-Heterocyclic
nitreniums
(NHNs)
are
isoelectronic
and
isostructural
analogues
of
N-heterocyclic
carbenes
(NHCs).
Unlike
NHCs,
NHNs
much
less
developed.
While
a
comprehensive
understanding
NHN
reactivity
remains
elusive,
recent
advancements
have
demonstrated
their
utility
as
Lewis
acid
catalysts,
photoreductants,
photooxidants,
leading
to
several
reaction
patterns.
In
this
short
review,
we
focus
on
the
applications
in
photoredox
reactions.
We
also
discuss
mechanisms
behind
these
transformations
outline
future
research
directions.
1
Introduction
2
Application
Nitreniums
Photoreductants
3
Facilitate
Photohomolysis
4
Photooxidants
5
Conclusion
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(16), P. 9223 - 9232
Published: April 17, 2023
Herein,
we
report
the
synthesis
of
an
acyclic
carbene-stabilized
diphospha(aminyl)
PNP
radical
CAACMePNPCAACMe4
(CAACMe
=
1-[2,6-bis(isopropyl)phenyl]-3,3,5,5-tetramethyl-2-pyrrolidinylidene)
by
a
facile
one-pot,
seven-electron
reduction
hexachlorophosphazene
chloride
[Cl3PNPCl3][Cl].
The
4
features
conjugated
framework
with
spin
density
primarily
localized
on
central
nitrogen
atom
as
well
flanking
carbenes.
Unlike
other
tripnictogen
radicals,
undergoes
one-electron
oxidation
and
to
yield
nonclassical
nitrenium
amide
species
[5]+
[6]-,
respectively.
cation
exhibits
conformational
flexibility
in
solution
state
between
expected
W-shaped
geometry
[5b]+
previously
unobserved
linear
heteroallene-type
structure
[5a]+,
which
was
characterized
solid
state.
equilibrium
explored
both
computationally
experimentally,
showing
that
[5a]+
is
favored
over
enthalpically
(ΔH
-2.9
×
103
±
80
J
mol-1)
entropically
(ΔS
4.2
0.25
mol-1
K-1).
formal
[6]-
displays
remarkable
its
coordination
chemistry
due
presence
multiple
Lewis
basic
centers,
evidenced
potassium
complex
K262,
μ,
κ-P,
η3-PNP
modes.
Protonation
leads
formation
amine
7,
trigonal
planar
around
nitrogen.
Chemical Science,
Journal Year:
2023,
Volume and Issue:
14(43), P. 12034 - 12040
Published: Jan. 1, 2023
Bench-stable
N-heterocyclic
nitrenium
ions
were
used
for
the
efficient
electrophilic
amination
of
organometallic
nucleophiles.
The
previously
unexplored
N
-alkyl/aryl
triazane
intermediates
reduced
to
produce
a
diverse
scope
primary
amines.
Journal of Computational Chemistry,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 30, 2024
Abstract
Cyclic
nitrenium
ions
containing
five‐membered
and
six‐membered
rings
are
available,
however,
the
seven‐membered
cyclic
(azepinium
ions)
rare.
The
chemistry
of
these
species
is
related
to
their
stability
originating
from
aromaticity
due
6π
electrons.
Very
few
theoretical
experimental
studies
have
been
conducted
on
azepinium
ions.
Related
clozapine
olanzapine
cations
(diazepinium
were
observed
during
drug
metabolism
studies.
In
this
work,
quantum
chemical
analysis
has
carried
out
estimate
stability,
aromaticity,
electrophilicity
several
derivatives
A
designed
carry
Δ
E
S‐T
values
in
range
50
kcal/mol
favoring
singlet
state;
π
donating
groups
at
2nd
position
increase
singlet‐triplet
energy
differences.
Most
substituents
reduce
NICS(1)
compared
parent
system.
Ring
fusion
with
heterocyclic
generally
increases
ion
ring
systems.
parameters
estimated
terms
HIA,
FIA,
ω
indicate
that
it
possible
fine‐tune
properties
appropriate
modulation.