Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: July 6, 2023
The
precise
activation
of
C-H
bonds
will
eventually
provide
chemists
with
transformative
methods
to
access
complex
molecular
architectures.
Current
approaches
selective
relying
on
directing
groups
are
effective
for
the
generation
five-membered,
six-membered
and
even
larger
ring
metallacycles
but
show
narrow
applicability
generate
three-
four-membered
rings
bearing
high
strain.
Furthermore,
identification
distinct
small
intermediates
remains
unsolved.
Here,
we
developed
a
strategy
control
size
strained
in
rhodium-catalysed
aza-arenes
applied
this
discovery
tunably
incorporate
alkynes
into
their
azine
benzene
skeletons.
By
merging
rhodium
catalyst
bipyridine-type
ligand,
three-membered
metallacycle
was
obtained
catalytic
cycle,
while
utilizing
an
NHC
ligand
favours
metallacycle.
generality
method
demonstrated
range
aza-arenes,
such
as
quinoline,
benzo[f]quinolone,
phenanthridine,
4,7-phenanthroline,
1,7-phenanthroline
acridine.
Mechanistic
studies
revealed
origin
ligand-controlled
regiodivergence
metallacycles.
Science,
Journal Year:
2023,
Volume and Issue:
381(6658), P. 660 - 666
Published: Aug. 10, 2023
Waste
plastics
are
an
abundant
feedstock
for
the
production
of
renewable
chemicals.
Pyrolysis
waste
produces
pyrolysis
oils
with
high
concentrations
olefins
(>50
weight
%).
The
traditional
petrochemical
industry
uses
several
energy-intensive
steps
to
produce
from
fossil
feedstocks
such
as
naphtha,
natural
gas,
and
crude
oil.
In
this
work,
we
demonstrate
that
oil
can
be
used
aldehydes
through
hydroformylation,
taking
advantage
olefin
functionality.
These
then
reduced
mono-
dialcohols,
oxidized
dicarboxylic
acids,
or
aminated
diamines
by
using
homogeneous
heterogeneous
catalysis.
This
route
high-value
oxygenated
chemicals
low-value
postconsumer
recycled
polyethylene.
We
project
produced
could
lower
greenhouse
gas
emissions
~60%
compared
their
petroleum
feedstocks.
Chemical Reviews,
Journal Year:
2023,
Volume and Issue:
123(15), P. 9139 - 9203
Published: July 5, 2023
Hydroamination,
the
addition
of
an
N–H
bond
across
a
C–C
multiple
bond,
is
reaction
with
great
synthetic
potential.
Important
advances
have
been
made
in
last
decades
concerning
catalysis
these
reactions.
However,
controlling
regioselectivity
amine
toward
formation
anti-Markovnikov
products
(addition
to
less
substituted
carbon)
still
remains
challenge,
particularly
intermolecular
hydroaminations
alkenes
and
alkynes.
The
goal
this
review
collect
systems
which
hydroamination
terminal
alkynes
has
achieved.
focus
will
be
placed
on
mechanistic
aspects
such
reactions,
discern
step
at
decided
unravel
factors
that
favor
regioselectivity.
In
processes
entailing
direct
alternative
pathways,
involving
several
reactions
accomplish
(formal
processes),
also
discussed
review.
catalysts
gathered
embrace
most
metal
groups
Periodic
Table.
Finally,
section
discussing
radical-mediated
metal-free
approaches,
as
well
heterogeneous
catalyzed
processes,
included.
Science,
Journal Year:
2024,
Volume and Issue:
383(6678), P. 77 - 81
Published: Jan. 4, 2024
Catalytic
methods
to
couple
alkene
and
amine
feedstocks
are
valuable
in
synthetic
chemistry.
The
direct
carbonylative
coupling
of
alkenes
amines
holds
promise
as
a
perfectly
atom-economical
approach
amide
synthesis,
but
general
remain
underdeveloped.
Herein,
we
report
an
hydroaminocarbonylation
catalyzed
by
unmodified,
inexpensive
cobalt
carbonyl
under
mild
conditions
low
pressure
promoted
light.
Silane
addition
after
the
reaction
enables
sequential
cobalt-catalyzed
reduction,
constituting
formal
hydroaminomethylation.
These
exhibit
exceptional
scope
across
both
components
with
high
chemo-
regioselectivity
proceed
efficiently
even
absence
solvent.
formation
hydridocobalt
through
photodissociation
ligand
is
proposed
enable
catalytic
activity
conditions,
which
addresses
long-standing
challenge
catalysis.
Journal of the American Chemical Society,
Journal Year:
2022,
Volume and Issue:
144(39), P. 17776 - 17782
Published: Sept. 22, 2022
A
mild
and
site-selective
hydroaminoalkylation
of
activated
unactivated
alkenes
via
dual
photoredox/Ni
catalysis
is
developed.
This
catalytic
strategy
enables
exclusive
access
to
α-selective
products,
which
complementary
previously
reported
photocatalytic
that
provides
the
β-selective
products.
The
chain-walking
a
Ni–H
intermediate
toward
carbonyl
allows
for
at
remote
sp3
C–H
sites.
method
tolerates
broad
substrate
scope
both
amines
as
well
providing
streamlined
synthesis
value-added
β-amino
acid
derivatives
from
readily
available
starting
materials.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(42), P. 23385 - 23394
Published: Oct. 12, 2023
A
mild
and
regiodivergent
aminoalkylation
of
unactivated
alkyl
halides
is
disclosed
via
a
dual
photoredox/nickel
catalysis.
Bipyridyl-type
ligands
without
an
ortho-substituent
control
the
site-selective
coupling
at
original
position,
while
ortho-disubstituted
tune
site-selectivity
remote,
unprefunctionalized
position.
Mechanistic
studies
combined
with
DFT
calculations
give
insight
into
mechanism
origins
ligand-controlled
regioselectivity.
Notably,
this
redox-neutral,
alkyl-alkyl
features
conditions,
broad
substrate
scope
for
both
partners,
excellent
offers
straightforward
way
α-alkylation
tertiary
amines
to
synthesize
structurally
diverse
alkylamines
value-added
amino
acid
derivatives.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(5), P. 3458 - 3470
Published: Jan. 25, 2024
Ligand
modulation
of
transition-metal
catalysts
to
achieve
optimal
reactivity
and
selectivity
in
alkene
hydrofunctionalization
is
a
fundamental
challenge
synthetic
organic
chemistry.
Hydroaminoalkylation,
an
atom-economical
approach
for
alkylating
amines
using
alkenes,
particularly
significant
amine
synthesis
the
pharmaceutical,
agrochemical,
fine
chemical
industries.
However,
existing
methods
usually
require
specific
substrate
combinations
precise
regio-
stereoselectivity,
which
limits
their
practical
utility.
Protocols
allowing
regiodivergent
hydroaminoalkylation
from
same
starting
materials,
controlling
both
regiochemical
stereochemical
outcomes,
are
currently
absent.
Herein,
we
report
ligand-controlled,
nickel-catalyzed
unactivated
alkenes
with
Chemical Communications,
Journal Year:
2023,
Volume and Issue:
59(36), P. 5395 - 5398
Published: Jan. 1, 2023
The
first
N-heterocyclic
carbene
organocatalytic
three-component
radical
relay
trifunctionalization
of
unactivated
alkenes
through
the
combination
remote
1,4-cyano
migration
and
alkylacylation
was
reported.
This
protocol
features
mild
reaction
conditions,
readily
available
materials,
excellent
regioselectivity,
capability
late-stage
functionalization.
Energy & Fuels,
Journal Year:
2023,
Volume and Issue:
37(13), P. 8919 - 8934
Published: June 27, 2023
Low-dosage
hydrate
inhibitors
(LDHIs)
are
used
to
prevent
gas
hydrates
from
plugging
upstream
and
oil
flow
lines.
LDHIs
come
in
two
main
classes,
kinetic
(KHIs)
anti-agglomerants
(AAs).
KHIs
delay
the
formation
process,
while
AAs
ultimately
disperse
any
formed
so
that
no
deposits
or
plugs
formed.
Currently,
KHI
formulations
deployed
field
contain
one
more
water-soluble
polyamides
with
optimized
hydrophobic
groups,
most
commercialized
cationic
quaternary
ammonium
surfactants
also
groups.
The
amine
oxide
group
is
closely
related
salts
but
has
zero
overall
charge
amide
as
a
result
of
strong
hydrogen-bonding
properties.
In
past
decade,
small
oxides
synergists,
polyamine
stand-alone
KHIs,
have
all
been
developed.
This
review
summarizes
contributions
development
amine-oxide-based
LDHIs.
includes
powerful
monoamine
synergists
for
polyamide
high-salinity-compatible
bis-amine
function
both
AAs.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(41)
Published: Aug. 23, 2023
An
iridium-catalyzed
remote
site-switchable
hydroarylation
of
alkenes
was
reported,
delivering
the
products
functionalized
at
subterminal
methylene
and
terminal
methyl
positions
on
an
alkyl
chain
controlled
by
two
different
ligands,
respectively,
in
good
yields
with
to
excellent
site-selectivities.
The
catalytic
system
showed
functional
group
tolerance
a
broad
substrate
scope,
including
unactivated
activated
alkenes.
More
importantly,
regioconvergent
transformations
mixtures
isomeric
were
also
successfully
realized.
results
mechanistic
studies
demonstrate
that
reaction
undergoes
chain-walking
process
give
[Ar-Ir-H]
complex
alkene.
subsequent
processes
proceed
through
modified
Chalk-Harrod-type
mechanism
via
migratory
insertion
alkene
into
Ir-C
bond
followed
C-H
reductive
elimination
afford
hydrofunctionalization
site-selectively.