Polyhedron,
Год журнала:
2024,
Номер
251, С. 116853 - 116853
Опубликована: Янв. 23, 2024
Iridium
dibromide
complexes
of
the
phenyldiimine
ligand
2,6-bis(1-((2,6-dimethylphenyl)imino)ethyl)phenyl,
trans-(XyPhDI)IrBr2L,
have
been
synthesized,
and
relative
Ir-L
BDFEs
experimentally
determined
for
a
wide
range
corresponding
adducts
ligands
L.
An
estimate
absolute
enthalpy
binding
has
obtained
from
dynamic
NMR
measurements.
The
results
DFT
calculations
are
in
very
good
agreement
with
experimental
values.
Computational
studies
were
extended
to
formation
(XyPhDI)IrH2
(XyPhDI)IrI,
as
well
other
(pincer)IrI
fragments,
(Phebox)IrI
(PCP)IrI,
enable
comparison
electronic
steric
effects
these
archetypal
pincer
ligands.
Attempts
reduce
(XyPhDI)IrBr2(MeCN)
hydride
or
an
IrI
complex
yielded
dinuclear
CN-bridged
methyl
on
cyanide-C-bound
Ir
center
(characterized
by
scXRD),
indicating
that
C-CN
bond
cleavage
took
place
at
center.
indicate
occurs
one
strong
assistance
coordination
CN
nitrogen
Organometallics,
Год журнала:
2022,
Номер
41(22), С. 3426 - 3434
Опубликована: Окт. 12, 2022
The
triphosphorus-coordinating
pincer
iridium
fragment
(tBuPPP)Ir
was
recently
reported
to
be
highly
active
for
the
catalytic
dehydrogenation
of
n-alkanes.
Dehydrogenation
is
calculated
regioselective
terminal
position
extremely
high
intermolecular
selectivity
observed
in
n-alkane/cycloalkane
competition
experiments
supports
prediction
regioselectivity
use
sterically
unhindered
hydrogen
acceptors
key
observing
activity
fragment.
4,4-Dimethylpent-1-ene
(TBP)
found
particularly
convenient
this
purpose.
With
commonly
used
acceptor
3,3-dimethylbut-1-ene
(TBE),
affords
n-alkane
at
a
rate
no
different
than
that
obtained
with
well-known
(iPrPCP)Ir.
However,
TBP
as
acceptor,
shows
much
greater
transfer
previously
catalysts,
affording
appreciable
rates
even
50
°C,
an
unprecedentedly
low
temperature
alkane
dehydrogenation.
Also
critical
identification
effective
catalyst
substrate
rather
"model"
substrate,
cyclooctane,
which
are
lower
those
Organic Letters,
Год журнала:
2023,
Номер
25(26), С. 4950 - 4954
Опубликована: Июнь 26, 2023
Asymmetric
transfer
hydrogenation
of
1-aryl-1-alkylethenes
with
ethanol
was
developed
a
chiral
(PCN)Ir
complex
as
the
precatalyst,
featuring
high
enantioselectivities,
good
functional
group
tolerance,
and
operational
simplicity.
The
method
is
further
applied
to
formal
intramolecular
asymmetric
alkenols
without
an
external
H-donor,
producing
tertiary
stereocenter
remote
ketone
simultaneously.
utility
catalytic
system
highlighted
by
gram
scale
synthesis
key
precursor
(R)-xanthorrhizol.
Polyhedron,
Год журнала:
2024,
Номер
251, С. 116853 - 116853
Опубликована: Янв. 23, 2024
Iridium
dibromide
complexes
of
the
phenyldiimine
ligand
2,6-bis(1-((2,6-dimethylphenyl)imino)ethyl)phenyl,
trans-(XyPhDI)IrBr2L,
have
been
synthesized,
and
relative
Ir-L
BDFEs
experimentally
determined
for
a
wide
range
corresponding
adducts
ligands
L.
An
estimate
absolute
enthalpy
binding
has
obtained
from
dynamic
NMR
measurements.
The
results
DFT
calculations
are
in
very
good
agreement
with
experimental
values.
Computational
studies
were
extended
to
formation
(XyPhDI)IrH2
(XyPhDI)IrI,
as
well
other
(pincer)IrI
fragments,
(Phebox)IrI
(PCP)IrI,
enable
comparison
electronic
steric
effects
these
archetypal
pincer
ligands.
Attempts
reduce
(XyPhDI)IrBr2(MeCN)
hydride
or
an
IrI
complex
yielded
dinuclear
CN-bridged
methyl
on
cyanide-C-bound
Ir
center
(characterized
by
scXRD),
indicating
that
C-CN
bond
cleavage
took
place
at
center.
indicate
occurs
one
strong
assistance
coordination
CN
nitrogen
