Chemical Society Reviews,
Journal Year:
2019,
Volume and Issue:
48(13), P. 3660 - 3673
Published: Jan. 1, 2019
This
review
summarizes
recent
advances
in
transition
metal
catalyzed
vertex-specific
BH
functionalization
ofo-carborane
for
controlled
synthesis
of
its
derivatives.
Bulletin of the Chemical Society of Japan,
Journal Year:
2020,
Volume and Issue:
94(3), P. 879 - 899
Published: Dec. 18, 2020
Abstract
Carboranes
are
a
class
of
carbon-boron
molecular
clusters,
possessing
extraordinary
characteristics
including
three-dimensional
aromaticity
conjugated
by
σ-bonds,
icosahedral
geometry
and
inherent
robustness.
They
finding
growing
applications
as
valuable
building
blocks
in
boron
neutron
capture
therapy
agents,
pharmacophores,
nanomaterials,
optoelectronic,
organometallic/coordination
chemistry
more.
Therefore,
the
effective
controlled
functionalization
carboranes
has
attracted
enormous
research
interests,
particularly
regio-
enantio-selective
cage
BH
derivatization
among
ten
chemically
similar
vertices
o-carboranes.
Only
recent
few
years,
significant
progress
been
made
transition
metal
catalyzed
vertex-specific
functionalization.
This
review
summarizes
advances
this
realm.
Journal of the American Chemical Society,
Journal Year:
2019,
Volume and Issue:
141(32), P. 12855 - 12862
Published: July 15, 2019
A
proof-of-principle
study
of
cascade
dehydrogenative
cross-coupling
carboranyl
carboxylic
acid
with
readily
available
benzamide
has
been
achieved,
resulting
in
the
facile
synthesis
previously
inaccessible
carborano-isoquinolinone
derivatives
a
simple
one-pot
process,
which
two
cage
B-H,
one
aryl
C-H,
and
N-H
bond
were
sequentially
activated
to
construct
efficiently
new
B-C
B-N
bonds,
respectively.
Under
suitable
reaction
conditions,
such
cyclization
can
be
stopped
at
first
B-H/C-H
step
give
series
α-carboranyl
benzamides,
suggesting
preferential
occurrence
over
that
B-N.
The
directing
group
plays
key
role
step,
is
then
removed
through
situ
decarboxylation.
CV
results
combined
control
experiments
indicate
high-valent
Ir(V)-species
may
involved
pathways,
crucial
for
reactions.
isolation
structural
identification
intermediate,
its
controlled
transformations,
deuterium
labeling
support
Ir-nitrene-mediated
amination
B-H/N-H
dehydrocoupling.
Journal of the American Chemical Society,
Journal Year:
2019,
Volume and Issue:
141(10), P. 4219 - 4224
Published: Feb. 24, 2019
A
proof-of-concept
example
of
catalytic
regioselective
cage
B(8)-H
functionalization
o-carboranes
has
been
disclosed
for
the
first
time.
Under
help
an
acylamino
directing
group
at
B(3),
a
series
B(8)-arylated,
B(4,7,8)-triarylated
and
B(4,7,8)-trifluorinated
o-carborane
derivatives
were
conveniently
prepared.
On
basis
isolation
key
intermediate,
deuterium
labeling
experiments
DFT
calculations,
reaction
mechanism
involving
high-valent
palladium
induced
"cage-walking"
from
B(4)
to
B(8)
vertex
is
proposed
account
activation.
Journal of the American Chemical Society,
Journal Year:
2020,
Volume and Issue:
142(22), P. 9890 - 9895
Published: May 12, 2020
Described
herein
is
the
first
iridium-catalyzed
cyclative
indenylation
through
sequential
B(4)–C
and
intramolecular
C–C
bond
formation
from
o-carboranes
propargyl
alcohols,
leading
to
of
B(4)-indenylated
with
excellent
regioselectivity
via
direct
B–H
activation.
Moreover,
regioselective
1,3-dienylation
has
been
accessed
activation,
dehydration,
decarboxylation,
producing
B(4)-dienylated
o-carboranes.
Journal of the American Chemical Society,
Journal Year:
2020,
Volume and Issue:
142(15), P. 6940 - 6945
Published: March 31, 2020
Copper-catalyzed
electrochemical
selective
cage
B–H
oxygenation
of
o-carboranes
has
been
achieved
for
the
first
time.
Under
a
constant
electric
current
(4.0
mA)
at
room
temperature,
copper-catalyzed
cross-coupling
carboranyl
amides
with
lithium
phenolates
results
in
formation
B(4,5)-diphenolated
via
direct
activation,
whereas
use
tert-butoxide
affords
B(4)-monooxygenated
products.
This
reaction
does
not
require
any
additional
chemical
oxidants
and
generates
H2
salt
as
byproducts.
Control
experiments
indicated
that
high-valent
Cu(III)
species
is
likely
involved
process.
Organic Letters,
Journal Year:
2019,
Volume and Issue:
21(22), P. 9276 - 9279
Published: Nov. 5, 2019
An
efficient
in
situ
Pd-NHC
catalytic
system
for
regioselective
arylation
of
B(3,6)-H
bonds
o-carborane
has
been
developed
the
first
time.
A
series
symmetric
and
unsymmetric
3,6-diaryl-o-carboranes
anchored
with
active
groups
have
synthesized
moderate
to
good
yields
under
mild
conditions.
This
work
offers
an
protocol
selective
activation
important
value
design
coupling
reactions
functionalization
o-carboranes.
Angewandte Chemie International Edition,
Journal Year:
2019,
Volume and Issue:
59(12), P. 4851 - 4855
Published: Dec. 25, 2019
Abstract
A
palladium‐catalyzed
highly
selective
3,4‐bifunctionalization
of
3‐I‐
o
‐carborane
has
been
developed,
leading
to
the
preparation
3‐alkenyl‐4‐R‐
‐carboranes
(R=alkyl,
alkynyl,
aryl,
allyl,
CN,
and
amido)
in
high
excellent
yields.
This
protocol
combines
sequential
activation
cage
B(3)−I
B(4)−H
bonds
by
Pd
migration
from
exo
‐alkenyl
sp
2
C
B(4),
which
is
driven
thermodynamic
force.
represents
a
brand‐new
strategy
for
bifunctionalization
carboranes
with
two
different
substituents.
