Palladium-Catalyzed Cross-Coupling Reactions of Carboranes with Alkenes via Selective B–H Bond Activation
Organic Letters,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 17, 2025
A
palladium-catalyzed
Heck-type
cross-coupling
reaction
of
carboranes
with
alkenes
in
1,1,1,3,3,3-hexafluoro-2-propanol
(HFIP)
was
realized.
This
shows
good
B(9)
selectivity
for
m-carboranes
and
is
also
suitable
o-
p-carborane.
Meanwhile,
a
series
mono-,
di-,
trisubstituted
were
compatible
substrates
to
afford
the
alkenylated
products
16–89%
yields.
The
1,2-bis(carboranyl)ethylene
first
synthesized
by
vinyltrimethylsilane
m-carborane.
Further
transformations
C═C
bond
product
examined
hydroboration
oxidation,
hydroboration,
bromination
generate
corresponding
B(9)-functionalized
m-carboranes.
Язык: Английский
Taming Inert B–H Bond with Low Energy Light: A Near-Infrared Light-Induced Approach to Facile Carborane Cluster-Amino Acid Coupling
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 1, 2025
The
selective
functionalization
of
inert
B–H
bonds
in
carborane
clusters
has
been
a
formidable
challenge.
Recent
advances
have
witnessed
such
reactions
through
photoredox
methods
utilizing
ultraviolet
or
visible
light
irradiation.
However,
high-energy
sources
often
suffer
from
poor
energy
efficiency,
limited
substrate
scope,
undesired
side
reactions,
and
low
scalability.
Here,
we
present
the
first
successful
bond
under
low-energy
near-infrared
(NIR)
using
carborane-based
electron
donor–acceptor
complex.
Both
photophysical
investigations
theoretical
modeling
reveal
facile
single-electron
transfer
cage
to
electron-deficient
photocatalyst,
generating
radical
NIR
follow-up
pathway
enables
direct
coupling
carboranes
with
amino
acids
oligopeptides,
yielding
diverse
array
carborane-functionalized
oligopeptides.
Beyond
expanding
known
chemical
space
boron
cluster
derivatives,
further
demonstrate
that
imaging
targeting
capabilities
could
serve
as
promising
multifunctional
carriers
for
neutron
capture
therapy.
Thus,
via
not
only
provides
straightforward
practical
strategy
synthetic
chemistry
but
also
lays
foundation
development
next-generation
boron-containing
biomolecules
advanced
functional
materials.
Язык: Английский
Post-coordination of Ru(II) Controlled Regioselective B(4)–H Acylmethylation of o-Carboranes with Sulfoxonium Ylides
Chemical Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
Despite
significant
progress
in
the
B-H
functionalization
of
carboranes,
development
cost-effective
catalytic
systems
devoid
noble
metals,
coupled
with
mechanistic
validation
regioselectivity
control,
remains
a
formidable
challenge.
Herein,
we
disclose
an
Ag
salt-free,
redox-neutral,
and
inexpensive
ruthenium(ii)-catalyzed
protocol
that
enables
exclusive
B(4)-H
acylmethylation
o-carboranes
through
novel
post-coordination
strategy.
By
exploiting
weakly
coordinating
carboxylic
acid
as
traceless
directing
group,
this
method
achieves
excellent
mono-site
selectivity
for
B-C(sp3)
bond
formation
using
diverse
sulfoxonium
ylides,
demonstrating
both
functional
group
tolerance
synthetic
scalability.
This
work
not
only
establishes
practical
platform
but
also
addresses
critical
questions
unresolved
prior
analogous
studies.
Through
deuterium
labeling,
situ
high-resolution
mass
spectrometry
(HRMS)
tracking,
single-crystal
X-ray
analysis
Ru
intermediates,
unequivocally
demonstrate
originates
from
unique
mode
Ru(ii).
The
catalyst
simultaneously
engages
enolizable
acylmethyl
moiety
mono-acylated
intermediate,
thereby
dictating
activation
trajectory.
Our
findings
establish
generalizable
regiocontrolled
carborane
while
defining
paradigms
transition
metal-mediated
chemistry.
Язык: Английский