Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
63(1)
Published: Nov. 21, 2023
Abstract
A
phosphine‐catalyzed
(3+2)
annulation
of
4‐acetoxy
allenoate
and
aldimine
with
the
assistance
AgF
is
described.
The
success
this
reaction
hinges
on
metathesis
between
enolate‐phosphonium
zwitterion
AgF,
leading
to
a
key
intermediate
comprising
silver
enolate
fluorophosphorane
P(V)‐moiety.
former
able
undergo
Mannich
aldimine,
whereas
latter
initiates
cascade
sequence
AcO‐elimination/aza‐addition,
thus
furnishing
P(III)/P(V)
catalysis.
By
taking
advantage
enolate,
preliminary
attempt
at
an
asymmetric
variant
was
conducted
combination
achiral
phosphine
catalyst
chiral
bis(oxazolinyl)pyridine
ligand
(PyBox),
giving
moderate
enantioselectivity.
Chemical Society Reviews,
Journal Year:
2023,
Volume and Issue:
53(2), P. 764 - 792
Published: Dec. 15, 2023
This
review
presents
a
group-wise
summary
of
ligand
enforced
non-VSEPR
geometries
in
compounds
the
p-block
elements
and
discusses
emergent
consequences
for
reactivity.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(3), P. 2005 - 2014
Published: Jan. 11, 2024
Delivering
metallomimetic
reactivity
from
simple
p-block
compounds
is
highly
desirable
in
the
search
to
replace
expensive,
scarce
precious
metals
by
cheap
and
abundant
elements
catalysis.
This
contribution
demonstrates
that
catalysis,
involving
facile
redox
cycling
between
P(III)
P(V)
oxidation
states,
possible
using
only
simple,
cheap,
readily
available
trialkylphosphines
without
need
enforce
unusual
geometries
at
phosphorus
or
use
external
oxidizing/reducing
agents.
Hydrodefluorination
aminodefluorination
of
a
range
fluoroarenes
was
realized
with
good
very
yields
under
mild
conditions.
Experimental
computational
mechanistic
studies
show
phosphines
undergo
oxidative
addition
fluoroaromatic
substrate
via
Meisenheimer-like
transition
state
form
fluorophosphorane.
undergoes
pseudotransmetalation
step
silane,
initial
fluoride
transfer
P
Si,
give
experimentally
observed
phosphonium
ions.
Hydride
hydridosilicate
counterion
then
leads
hydridophosphorane,
which
reductive
elimination
product
reform
phosphine
catalyst.
behavior
analogous
many
classical
transition-metal-catalyzed
reactions
so
rare
example
both
functional
mechanistically
catalysis
main-group
element
system.
Crucially,
reagents
used
are
commercially,
easy
handle,
making
these
realistic
prospect
wide
academic
industrial
settings.
Inorganic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 6, 2025
Herein,
we
report
the
isolation
of
pyridine
moiety-functionalized
SiNSi
pincer-based
bis-silylene
ligand
(1)
and
its
reactivity
toward
various
halide
precursors
(X
=
Br
I)
group
13
elements
(M
Al,
Ga,
In).
This
gave
us
straightforward
access
to
pincer-coordinated
cations
(2–7).
These
complexes
are
duly
characterized
by
single-crystal
X-ray
diffraction
studies,
multinuclear
magnetic
resonance
spectroscopy
(1H,
13C,
29Si),
high-resolution
mass
spectrometry
techniques.
Their
electronic
properties
were
further
analyzed
with
help
quantum
chemical
calculations.
Chemistry - A European Journal,
Journal Year:
2023,
Volume and Issue:
29(39)
Published: April 12, 2023
Abstract
The
steric
tuning
of
a
tridentate
acridane‐derived
NNN
pincer
ligand
allows
for
the
isolation
strictly
T‐shaped
phosphine
that
exhibits
ambiphilic
reactivity.
Well‐defined
phosphorus‐centered
reactivity
towards
nucleophiles
and
electrophiles
is
reported,
contrasting
with
prior
reports
on
this
class
compounds.
Reactions
oxidants
are
also
described.
latter
result
in
two‐electron
oxidation
phosphorus
atom
from
+III
to
+V
accompanied
by
strong
geometric
distortion
ligand.
By
contrast,
cooperative
activation
E−H
(HCl,
HBcat,
HOMe)
bonds
proceeds
retention
redox
state.
When
using
H
2
O
as
substrate,
reaction
results
full
disassembly
its
constituent
atoms,
highlighting
potential
platform
small
molecule
reactions.
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: May 29, 2024
Abstract
Phosphanorcaradienes
are
an
appealing
class
of
phosphorus
compounds
that
can
serve
as
synthons
transient
phosphinidenes.
However,
the
synthesis
such
species
is
a
formidable
task
owing
to
their
intrinsic
high
reactivity.
Herein
we
report
straightforward
synthesis,
characterization
and
reactivity
studies
phosphanorcaradiene,
in
which
one
benzene
rings
flanking
fluorenyl
substituents
intramolecularly
dearomatized
through
attachment
atom.
It
facilely
obtained
by
reduction
phosphorus(III)
dichloride
precursor
with
potassium
graphite.
Despite
being
thermally
robust,
it
acts
synthetic
equivalent
phosphinidene.
reacts
trimethylphosphine
isonitrile
yield
phosphanylidene-phosphorane
1-phospha-3-azaallene,
respectively.
When
treated
two
molar
equivalents
azide,
iminophosphane
bis(imino)phosphane
isolated,
Moreover,
capable
activating
ethylene
alkyne
afford
[1
+
2]
cycloaddition
products,
well
oxidative
cleavage
Si–H
N–H
bonds
secondary
phosphines.
All
reactions
proceed
smoothly
at
room
temperature
without
presence
transition
metals.
The
driving
force
for
these
most
likely
ring-constraint
three-membered
PC
2
ring
recovery
aromaticity
ring.
Chemical Communications,
Journal Year:
2023,
Volume and Issue:
59(66), P. 9918 - 9928
Published: Jan. 1, 2023
The
icosahedral
carborane
cluster
can
accept
two
electrons
and
change
from
a
closed
closo
-form
to
an
open
nido
-form.
This
transformation
unlocks
the
potential
for
bond
activation
chemistry,
uranyl
capture,
stabilization
of
low-valent
centers.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(49)
Published: Sept. 28, 2023
Organobismuth-catalyzed
transfer
hydrogenation
has
recently
been
disclosed
as
an
example
of
low-valent
Bi
redox
catalysis.
However,
its
mechanistic
details
have
remained
speculative.
Herein,
we
report
experimental
and
computational
studies
that
provide
insights
into
a
Bi-catalyzed
azoarenes
using
p-trifluoromethylphenol
(4)
pinacolborane
(5)
hydrogen
sources.
A
kinetic
analysis
elucidated
the
rate
orders
in
all
components
catalytic
reaction
determined
1
(2,6-bis[N-(tert-butyl)iminomethyl]phenylbismuth)
is
resting
state.
In
azobenzene
4,
equilibrium
between
⋅
[OAr]2
(Ar=p-CF3
-C6
H4
)
observed,
thermodynamic
parameters
are
established
through
variable-temperature
NMR
studies.
Additionally,
pKa
-gated
reactivity
validating
proton-coupled
nature
transformation.
The
ensuing
crystallographically
characterized,
shown
to
be
rapidly
reduced
presence
5.
DFT
calculations
indicate
rate-limiting
transition
state
which
initial
N-H
bond
formed
via
concerted
proton
upon
nucleophilic
addition
hydrogen-bonded
adduct
4.
These
guided
discovery
second-generation
catalyst,
lower
energy,
leading
at
catalyst
loadings
cryogenic
temperature.
