Abstract
Transition
metal
catalysis
plays
a
pivotal
role
in
chemical
synthesis.
Noble
metals
often
grab
significant
attention
organometallic
due
to
their
high
reactivity.
However,
the
serious
issues
associated
with
these
such
as
low
abundance,
toxicity,
geopolitical
limitations,
and
volatile
prices
are
driving
scientific
community
discover
sustainable
alternatives.
In
this
context,
iron
appears
be
first
choice
an
alternative
its
unique
properties,
including
range
of
stable
oxidation
states,
Lewis
acidity,
abundance
earth‘s
crust,
toxicity.
Over
past
two
decades,
substantial
progress
has
been
made
catalysis.
This
overview
examines
recent
developments
iron‐catalyzed
industrially
relevant
transformations
hydroformylation,
olefin
isomerization,
hydrosilylation,
hydrophosphination,
carbonylation,
Wacker‐type
oxidation,
plastic
depolymerization.
As
witnessed
throughout
review,
performance
can
significantly
altered
by
suitable
ligand
selection
tailoring
electronic
steric
properties
center.
While
noble
remain
industry
work‐horse,
is
inching
closer
extensive
understanding,
it
may
replace
near
future.
JACS Au,
Год журнала:
2024,
Номер
4(11), С. 4234 - 4248
Опубликована: Сен. 18, 2024
With
growing
efforts
pushing
toward
sustainable
catalysis,
using
earth-abundant
metals
has
become
increasingly
important.
Here,
we
present
the
first
examples
of
cobalt
PC
The
example
of
iron-catalyzed
alkenes
migratory
silylation
and
transposition
has
been
demonstrated,
affording
a
tunable
approach
to
synthesize
thermodynamically
stable
allylsilanes
internal
with
high
efficiency
regioselectivity.
These
reactions
showcase
several
advantageous
features,
including
good
functional
group
tolerance,
excellent
regioselectivity,
broad
substrate
scope,
scalability
gram-scale
synthesis,
late-stage
functionalization
bio-relevant
molecules.
Furthermore,
the
relay
catalytic
mechanism
silylation,
involving
both
iron-silyl
iron-hydride
intermediates,
provides
valuable
insights
into
coupling
reactions,
opening
new
avenues
for
development
novel
transformations
under
iron
catalysis.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 22, 2025
Olefin
isomerization
can
not
only
convert
terminal
olefins
into
higher-value
internal
but
also
serve
as
a
bridge
to
connect
with
the
functionalization
reaction.
However,
traditional
methods,
such
base-mediated
and
transition-metal-mediated
approaches,
still
face
challenges
like
harsh
conditions,
low
trans/cis
(E/Z)
ratios,
unrecyclable
metals,
industrial
scalability.
Herein,
we
report
that
C-H
bond
could
be
activated
at
cathode
form
hydride
ions
(H-)
carbon
radicals,
which
initiate
olefin
via
radical
mechanism
without
base
or
metal
catalyst
assistance.
Through
this
new
mechanism,
various
substrates,
including
chemicals
significant
demand,
effectively
converted
high
yields,
excellent
E/Z
scalability,
all
while
requiring
catalytic
amount
of
electrons.
Furthermore,
electrochemical
system
was
successfully
applied
overcome
challenge
electrocarboxylation
nonconjugated
dioxide
(CO2)
by
isomerizing
conjugated
olefins.
This
work
makes
contribution
chemical
science
for
activation,
opens
way
promising
applications
in
isomerization-functionalization
Chemistry - A European Journal,
Год журнала:
2023,
Номер
29(63)
Опубликована: Авг. 9, 2023
The
geometrical
regioselective
E→Z
isomerization
of
a
conjugated
alkene
under
thermal
activation
pose
challenge
due
to
microscopic
reversibility.
Herein
we
report
that
such
reversibility
issues
can
be
circumvented
by
integrating
with
subsequent
cyclization
cascade,
particularly
in
the
absence
commonly
employed
light,
acids,
or
metal-catalysts.
Thus,
linearly
dienals
mixture
toluene-alcohol
(2
:
1)
solvents
only
alcohol
at
60-70
°C
converted
γ-alkoxybutenolides
moderate
good
yields.
intermediary
2Z,4E-isomer
isolated,
which
includes
first
example
isolating
product
conditions.
Density
functional
theory
(DFT)
studies
have
been
shed
light
on
feasibility
and
ensuing
cascade
sequences.
It
has
observed
2E,4E→2Z,4E
dienal
is
thermodynamically
facile
(ΔG
<0)
process.
Structural
elucidation
further
reveals
presence
certain
charge
transfer
non-covalent
interaction
may
primary
reasons
for
enhanced
stability
2Z,4E-isomer.
thermodynamic
plausibility
reaction
from
Z-isomer
anticipated
polar
protic
solvent
(here
MeOH)
also
explicated.
Out
two
probable
pathways,
"hemiacetal
pathway"
involving
relay
proton
kinetically
more
feasible
diminished
barrier
than
"conjugate
addition
pathway".
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(7), С. 4319 - 4325
Опубликована: Март 23, 2024
Earth-abundant-metal
catalyzed
double
bond
transposition
offers
a
sustainable
and
atom-economical
route
toward
the
synthesis
of
internal
alkenes.
With
an
emphasis
specifically
on
olefins
ethers,
isomerization
allylic
amines
has
been
particularly
under
represented
in
literature.
Herein,
we
report
efficient
methodology
for
selective
N-allylic
organic
compounds,
including
amines,
amides,
imines.
The
reaction
is
by
neutral
PCNHCP
cobalt(I)
pincer
complex
proceeds
via
π-allyl
mechanism.
occurs
readily
at
80–90
°C,
it
compatible
with
wide
variety
functional
groups.
situ
formed
enamines
could
additionally
be
used
one-pot
inverse-electron-demand
Diels–Alder
to
furnish
series
diversely
substituted
heterobiaryls,
which
further
discussed
this
report.
ACS Catalysis,
Год журнала:
2024,
Номер
14(17), С. 13174 - 13180
Опубликована: Авг. 17, 2024
An
additive-free
manganese-catalyzed
isomerization
of
terminal
alkenes
to
internal
is
described.
This
reaction
implementing
an
inexpensive
nonprecious
metal
catalyst.
The
most
efficient
catalyst
the
borohydride
complex
cis-[Mn(dippe)(CO)2(κ2-BH4)].
operates
at
room
temperature,
with
a
loading
2.5
mol
%.
A
variety
effectively
and
selectively
transformed
into
respective
E-alkenes.
Preliminary
results
show
chain-walking
elevated
temperature.
Mechanistic
studies
were
carried
out,
including
stoichiometric
reactions
in
situ
NMR
analysis.
These
experiments
are
flanked
by
computational
studies.
Based
on
these,
catalytic
process
initiated
liberation
"BH3"
as
THF
adduct.
double
bond
insertion
M-H
species,
leading
alkyl
intermediate,
followed
β-hydride
elimination
opposite
position
afford
product.
An
additive-free
manganese-catalyzed
isomerization
of
terminal
alkenes
to
internal
is
described.
This
reaction
atom
economic,
implementing
an
inexpensive,
non-precious
metal
catalyst.
The
most
efficient
catalyst
the
borohydride
complex
cis-[Mn(dippe)(CO)2(κ2-BH4)].
operates
at
room
temperature
with
a
loading
2.5
mol
%.
A
variety
are
effectively
and
selectively
transformed
respective
E-alkenes.
Preliminary
results
show
chain
walking
elevated
temperature.
Mechanistic
studies
were
carried
out
including
stochiometric
reactions
in
situ
NMR
analysis.
These
experiments
flanked
by
computational
studies.
Based
on
these,
catalytic
process
initiated
liberation
“BH3”
as
hydroborated
alkene.
double
bond
insertion
into
M–H
species
leading
alkyl
intermediate,
followed
β-hydride
elimination
opposite
position
afford
product.
Abstract
The
catalytic
one‐bond
isomerization
(transposition)
of
1‐alkenes
is
an
emerging
approach
to
Z
‐2‐alkenes.
Design
more
selective
catalysts
would
benefit
from
a
mechanistic
understanding
factors
controlling
selectivity.
We
propose
here
reaction
pathway
for
cis
‐Mo(CO)
4
(PCy
3
)(piperidine)
(
),
precatalyst
that
shows
high
selectivity
transposition
alpha
olefins
(e.
g.,
1‐octene
2‐octene,
18
:
1
E
at
74
%
conversion).
Computational
modeling
pathways
and
isotopic
labeling
suggests
the
takes
place
via
allyl
(1,3‐hydride
shift)
pathway,
where
oxidative
addition
fac
‐(CO)
Mo(PCy
)(η
2
‐alkene)
followed
by
hydride
migration
one
position
C
carbon)
another
hydride/CO
exchanges.
Calculated
barriers
are
lower
than
explored
alternative
mechanisms
change
hapticity,
rotation).
To
our
knowledge,
this
first
study
such
in
alkene
isomerization.
