Dalton Transactions,
Год журнала:
2022,
Номер
51(7), С. 2696 - 2707
Опубликована: Янв. 1, 2022
The
novel
dimeric
iodo-iridium(III)
complex,
[Ir(Cp*CONMe2)I2]2,
(Cp*CONMe2
=
η5-N,N-2,3,4,5-hexamethylcyclopenta-2,4-diene
carboxamide)
bearing
an
amide
moiety
within
the
tetramethylcyclopentadiene
ring,
has
been
synthesised
and
characterised.
ligand
Cp*CONMe2
is
as
two
regioisomers,
however
2-substituted
isomer
exists
distinguishable
conformers
due
to
restricted
rotation
about
carbonyl
carbon
ring
carbon.
relative
acidities
of
Cp*
are
compared
by
their
rates
H/D
exchange.
iridium
complex
N,N-2,3,4,5-hexamethylcyclopenta-2-4-diene
carboxamide
[IrCp*CONMe2]
(R,R)-1,2-diphenyl-N'-tosylethane-1,2-diamine
((R,R)-TsDPEN)
evaluated
in
transfer
hydrogenation
imines
under
acidic
conditions
-
a
5
:
2
molar
ratio
formic
acid
triethylamine
hydride
source
for
1-methyl-3,4-dihydroisoquinoline
(DHIQ)
its
6,7-dimethoxy
derivative
acetonitrile.
A
decreasing
enantiomeric
excess
with
reaction
progress
attributed
different
kinetic
orders
formation
product
amine
enantiomers.
pseudo
zero-order
R-amine
may
be
pre-steady-state
less
stable
form
diastereomeric
catalyst.
By
contrast,
both
amines
from
1-fluorinated
methyl
DHIQs
substrates
reduction
formed
first-order
processes.
ACS Catalysis,
Год журнала:
2022,
Номер
12(17), С. 10793 - 10800
Опубликована: Авг. 19, 2022
The
asymmetric
synthesis
of
optically
pure
and
conformationally
locked
oxabenzo[5]helicenes
bearing
pyridin-2-yl
or
isoquinolin-3-yl
substituents
their
transformation
into
the
corresponding
cycloiridated
organometallics
are
described.
These
helically
chiral
Cp*IrIII(X)C,N-complexes
(X
=
Cl,
I)
also
contain
a
configurationally
unstable
pseudotetrahedral
iridium
center.
This
center
undergoes
epimerization
at
room
temperature,
its
relative
stereochemistry,
especially
in
solid
state,
depends
on
nature
coordinated
ligands.
Cycloiridated
helicenes
were
used
transfer
hydrogenation
prochiral
aromatic
imines
with
formic
acid/triethylamine
to
reach
up
96:4
er.
It
is
assumed
that
chirality
controlled
by
auxiliary
helix
rather
than
IrIII
stereogenic
iridacycles.
ACS Catalysis,
Год журнала:
2020,
Номер
10(23), С. 14290 - 14301
Опубликована: Ноя. 23, 2020
Development
of
metal-free
strategies
for
stereoselective
hydrogenation
unsaturated
substrates
is
particular
interest
in
asymmetric
synthesis.
The
emerging
chemistry
frustrated
Lewis
pairs
offers
a
promising
approach
along
this
line
as
demonstrated
by
recent
achievements.
However,
the
stereocontrol
elements
these
reactions
are
not
clearly
recognized
thus
far.
Herein,
we
analyze
origin
stereoinduction
direct
imines
catalyzed
set
chiral
boranes.
We
use
tools
computational
to
describe
elementary
steps
catalytic
cycle,
and
pay
special
attention
stereoselectivity-determining
hydride
transfer
process.
enantioselectivities
predicted
applied
very
good
agreement
with
previous
experimental
observations.
find
that
stereoselectivity
governed
thermodynamically
less
favored
conformer
borohydride
intermediate
experimentally
observed
form.
most
transition
states
stabilized
specific
aryl–aryl
alkyl–aryl
noncovalent
interactions,
which
play
an
important
role
stereoinduction.
This
insight
exploited
proposing
additional
borane
variants
improve
enantioselectivity,
could
be
Angewandte Chemie International Edition,
Год журнала:
2021,
Номер
60(28), С. 15524 - 15532
Опубликована: Апрель 22, 2021
Abstract
We
found
that
cyclometalated
cyclopentadienyl
iridium(III)
complexes
are
uniquely
efficient
catalysts
in
homogeneous
hydrogenation
of
oximes
to
hydroxylamine
products.
A
stable
iridium
C,N‐chelation
is
crucial,
with
alkoxy‐substituted
aryl
ketimine
ligands
providing
the
best
catalytic
performance.
Several
Ir‐complexes
were
mapped
by
X‐ray
crystal
analysis
order
collect
steric
parameters
might
guide
a
rational
design
even
more
active
catalysts.
broad
range
and
oxime
ethers
activated
stoichiometric
amounts
methanesulfonic
acid
reduced
at
room
temperature,
remarkably
without
cleavage
fragile
N−O
bond.
The
exquisite
functional
group
compatibility
our
system
was
further
demonstrated
additive
tests.
Experimental
mechanistic
investigations
support
an
ionic
platform,
suggest
role
for
Brønsted
beyond
proton
source.
Our
studies
provide
deep
understanding
this
novel
acidic
may
facilitate
its
improvement
application
other
challenging
substrates.
Organometallics,
Год журнала:
2023,
Номер
42(7), С. 505 - 537
Опубликована: Март 20, 2023
This
report
provides
an
overview
of
the
use
phosphaalkenes
(C═P)
in
syntheses
various
complexes.
Going
through
successive
complexes
containing
d-block
metals,
we
sought
how
this
area
chemistry
was
formed
over
years.
Additionally,
work
contains
information
on
possible
coordination
types
and
means
constructing
In
addition,
review
reveals
reactivities
phosphaalkene
with
a
strong
emphasis
catalytic
properties.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(13), С. 8865 - 8876
Опубликована: Март 12, 2024
Formate
is
a
major
reactive
carbon
species
in
one-carbon
metabolism,
where
it
serves
as
an
endogenous
precursor
for
amino
acid
and
nucleic
biosynthesis
cellular
source
of
NAD(P)H.
On
the
other
hand,
aberrant
elevations
formate
are
connected
to
progression
serious
diseases,
including
cancer
Alzheimer's
disease.
Traditional
methods
detection
biological
environments
often
rely
on
sample
destruction
or
extensive
processing,
resulting
loss
spatiotemporal
information.
To
help
address
these
limitations,
here
we
present
design,
synthesis,
evaluation
first-generation
activity-based
sensing
system
live-cell
imaging
that
relies
iridium-mediated
transfer
hydrogenation
chemistry.
facilitates
aldehyde-to-alcohol
conversion
various
fluorophore
scaffolds
enable
fluorescence
this
unit,
through
two-color
ratiometric
response
with
internal
calibration.
The
two-component
probe
can
detect
changes
levels
living
cells
high
selectivity
over
potentially
competing
analytes.
Moreover,
visualize
fluxes
alterations
pathways
cell-based
models
human
colon
cancer,
presaging
potential
utility
chemical
approach
continuum
between
metabolism
signaling
diseases.
The Chemical Record,
Год журнала:
2021,
Номер
21(6), С. 1506 - 1534
Опубликована: Май 3, 2021
Abstract
Cyclometallated
complexes
are
well‐known
and
have
found
many
applications.
This
article
provides
a
short
review
on
the
progress
made
in
synthesis
application
to
catalysis
of
cyclometallated
half‐sandwich
Cp*Ir(III)
(Cp*:
pentamethylcyclopentadienyl)
since
2017.
Covered
iridacycles
featuring
conventional
C,N
chelates
less
common
metallocene
carbene‐derived
C,C
ligands.
is
followed
by
an
overview
studies
their
applications
ranging
from
asymmetric
hydrogenation,
transfer
hydrosilylation
dehydrogenation.
Abstract
Catalytic
partial
reduction
of
N‐heteroarenes
with
H
2
or
H[E]
(E=Si,
B‐based)
has
been
a
useful
and
general
method
for
synthesis
broad
range
dihydropyridines
(DHP)
dihydroquinolines
(DHQ).
In
recent
seven
years,
one
the
most
notable
advances
in
this
context
is
being
able
to
utilize
earth‐abundant
inexpensive
first‐row
transition
metal‐based
catalytic
systems.
These
procedures
are
generally
considered
more
environmentally
benign
sustainable
when
compared
conventional
systems
relying
on
precious
metals.
This
Review
describes
20
molecular
based
metals
selective
single
hydroelementation
pyridines
quinolines
surrogate,
hydrosilanes,
hydroboranes
providing
1,2‐
1,4‐dihydropyridines
‐dihydroquinolines.
The
observed
reaction
profiles
such
as
scope
activity
briefly
presented,
while
proposed
working
modes
over
series
elemental
steps
–
H−[E]
bond
cleavage,
hydride
(H
−
)
hydrogen
atom
(H⋅)
transfer,
product
release,
discussed
detail
basis
experimental
and/or
computational
mechanistic
observations
insights.