ChemistrySelect,
Journal Year:
2023,
Volume and Issue:
8(25)
Published: July 3, 2023
Abstract
Reduction
of
amides
to
amines
is
an
attractive
subject
in
organic
synthesis.
Ca(CH
2
C
6
H
4
NMe
‐
o
)
(THF)
,
easily
accessible
main‐group
complex,
on
combination
with
pinacolborane
(HBpin)
could
serve
as
a
highly
active
catalyst
system
the
reduction
primary,
secondary
and
tertiary
into
corresponding
amines.
This
protocol
showed
good
tolerance
for
functional
groups
heteroatoms,
aimed
products
be
obtained
gram‐scale.
The
species
this
transformation
was
supposed
calcium
hydride.
Chemical Reviews,
Journal Year:
2022,
Volume and Issue:
122(9), P. 8261 - 8312
Published: March 7, 2022
The
addition
of
a
B–H
bond
to
an
unsaturated
(polarized
or
unpolarized)
is
powerful
and
atom-economic
tool
for
the
synthesis
organoboranes.
In
recent
years,
s-block
organometallics
have
appeared
as
alternative
catalysts
transition-metal
complexes,
which
traditionally
catalyze
hydroboration
bonds.
Because
rapid
development
in
field
bonds
catalyzed
by
alkali
(Li,
Na,
K)
alkaline
earth
(Mg,
Ca,
Sr,
Ba)
metals,
we
provide
detailed
updated
comprehensive
review
that
covers
synthesis,
reactivity,
application
metal
polarized
well
carbon–carbon
Moreover,
describe
main
reaction
mechanisms,
providing
valuable
insight
into
reactivity
catalysts.
Finally,
compare
these
complexes
with
other
redox-neutral
catalytic
systems
based
on
p-block
metals
including
aluminum
f-block
lanthanides
early
actinides.
this
review,
aim
comprehensive,
authoritative,
critical
assessment
state
art
within
highly
interesting
research
area.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
60(29), P. 16035 - 16043
Published: April 24, 2021
Reductive
transformations
of
easily
available
oxidized
matter
are
at
the
heart
synthetic
manipulation
and
chemical
valorization.
The
applications
catalytic
hydrofunctionalization
benefit
from
use
liquid
reducing
agents
operationally
facile
setups.
Metal-catalyzed
hydroborations
provide
a
highly
prolific
platform
for
reductive
valorizations
stable
C=X
electrophiles.
Here,
we
report
an
especially
facile,
broad-scope
reduction
various
functions
including
carbonyls,
carboxylates,
pyridines,
carbodiimides,
carbonates
under
very
mild
conditions
with
inexpensive
pre-catalyst
Mn(hmds)2
.
reaction
could
be
successfully
applied
to
depolymerizations.
Chemistry - A European Journal,
Journal Year:
2023,
Volume and Issue:
29(38)
Published: April 20, 2023
A
fluorenyl-tethered
N-heterocyclic
carbene
LH
(LH=[(Flu)H-(CH2
)2
-NHCDipp
])
and
its
monoanionic
version
L-
are
explored
in
complexation
with
zinc
towards
the
hydroboration
of
N-heteroarenes,
carbonyl,
ester,
amide,
nitrile
under
ambient
condition.
The
N-heteroarenes
exhibit
high
1,2-regioselectivity
which
is
justified
by
computational
analyses.
relative
rates
differently
p-substituted
(electron
donating
vs.
withdrawing)
pyridines
also
addressed.
monodentate
offers
a
better
catalytic
activity
than
chelating
for
steric
reasons
despite
both
giving
three-coordinate
complexes.
mechanism
involves
Zn-H
species
at
heart
these
processes
trapped
Ph2
CO.
Computational
studies
suggest
that
barrier
to
form
hydride
complex
comparable
required
following
transfer
pyridine.
The Journal of Organic Chemistry,
Journal Year:
2022,
Volume and Issue:
87(5), P. 3442 - 3452
Published: Feb. 10, 2022
Lithium-promoted
hydroboration
of
alkynes
and
alkenes
using
commercially
available
hexamethyldisilazane
lithium
as
a
precatalyst
HBpin
hydride
source
has
been
developed.
This
method
will
be
appealing
for
organic
synthesis
because
its
remarkable
substrate
tolerance
good
yields.
Mechanistic
studies
revealed
that
the
proceeds
through
in
situ-formed
BH3
species,
which
acts
to
drive
turnover
alkenes.
Chemical Communications,
Journal Year:
2023,
Volume and Issue:
59(16), P. 2255 - 2258
Published: Jan. 1, 2023
This
work
describes
a
transition
metal-free
methodology
involving
an
efficient
and
controlled
reduction
of
isocyanates
to
only
formamide
derivatives
using
pinacolborane
(HBpin)
as
the
hydrogenating
agent
bis(phosphino)carbazole
ligand
stabilized
magnesium
methyl
complex
(1)
catalyst.
A
large
number
substrates
undergo
selective
hydroboration
give
exclusively
N-boryl
formamides.
Organometallics,
Journal Year:
2021,
Volume and Issue:
40(13), P. 2133 - 2138
Published: June 24, 2021
The
recently
published
silylene
with
a
tris(trimethylsilyl)
group,
PhC(NtBu)2SiSi(SiMe3)3
(1),
was
reacted
the
organic
azides
such
as
SiMe3N3
and
AdN3
to
form
respective
hypersilylsilaimines,
PhC(NtBu)2Si(═NR)Si(SiMe3)3
2
(R
=
SiMe3)
3
Ad).
B–H
bond
of
HBpin
or
HBcat
split
across
Si═N
upon
reaction
2,
which
generated
4
5,
respectively.
However,
we
could
not
obtain
crystals
5
appropriate
for
X-ray
diffraction.
Subsequently,
performed
analogous
reactions
related
silaimine
PhC(NtBu)2Si(═NSiMe3)N(SiMe3)2
(2′)
isolated
similar
activated
products
6
7.
2′
HBCl2
resulted
in
donor
stabilized
silyl
cations
(8
9)
supported
by
an
amidinate
ligand.
The Journal of Organic Chemistry,
Journal Year:
2022,
Volume and Issue:
87(2), P. 1098 - 1109
Published: Jan. 10, 2022
The
reactions
of
the
N-heterocyclic
carbene-phosphinidene
adducts
(NHC)PSiMe3
and
(NHC)PH
with
dinuclear
ruthenium
osmium
complexes
[(η6-p-cymene)MCl2]2
(M
=
Ru,
Os)
afforded
half-sandwich
[(η6-p-cymene){(NHC)P}MCl]
[(η6-p-cymene){(NHC)PH}MCl2]
two-
three-legged
piano-stool
geometries,
respectively
(NHC
IDipp,
IMes;
IDipp
1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene;
IMes
1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene).
were
initially
tested
as
precatalysts
for
hydroboration
benzonitrile,
most
active
species,
complex
[(η6-p-cymene){(IMes)P}RuCl],
was
further
used
efficient
a
wide
range
(ca.
50
substrates)
nitriles,
carboxylic
esters,
carboxamides
in
neat
pinacolborane
(HBpin)
under
comparatively
mild
reaction
conditions
(60-80
°C,
3-5
mol
%
catalyst
loading).
Preliminary
mechanistic
kinetic
studies
are
reported,
stoichiometric
HBpin
indicate
initial
formation
monohydride
[(η6-p-cymene){(IMes)P}RuH]
putative
catalytically
species.
