Canadian Journal of Chemistry,
Journal Year:
2021,
Volume and Issue:
100(2), P. 98 - 103
Published: May 6, 2021
Carbon–carbon
bond
formation
is
the
core
of
organic
synthesis,
in
which
organometallic
reagents
play
key
role
forms
1,2-nucleophilic
additions,
conjugate
and
transition-metal
catalyzed
cross-couplings.
These
reactions
have
enabled
production
a
wide
range
molecules
our
society.
Despite
enormous
power
chemical
they
inherent
drawbacks
eyes
future
sustainability.
This
account
summarizes
efforts
over
past
three
decades
on
exploration
new
scientific
means
to
overcome
limitations
these
classical
reactions.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
60(23), P. 13098 - 13104
Published: March 23, 2021
Abstract
Conventional
approaches
for
Pd‐catalyzed
ring‐opening
cross‐couplings
of
gem
‐difluorocyclopropanes
with
nucleophiles
predominantly
deliver
the
β‐fluoroalkene
scaffolds
(linear
selectivity).
Herein,
we
report
a
cooperative
strategy
that
can
completely
switch
reaction
selectivity
to
give
alkylated
α‐fluoroalkene
skeletons
(branched
The
unique
reactivity
hydrazones
enables
analogous
inner‐sphere
3,3′‐reductive
elimination
driven
by
denitrogenation,
as
well
assistance
steric‐embedded
N
‐heterocyclic
carbene
ligand,
are
key
regioselectivity.
A
wide
range
derived
from
naturally
abundant
aryl
and
alkyl
aldehydes
applicable,
various
‐difluorocyclopropanes,
including
modified
pharmaceutical
biological
molecules,
be
efficiently
functionalized
high
value
α‐fluorinated
alkene
motifs
under
mild
conditions.
Angewandte Chemie International Edition,
Journal Year:
2021,
Volume and Issue:
61(10)
Published: Nov. 15, 2021
The
simple
and
efficient
conversion
of
carbonyl
compounds
into
functionalized
alkanes
via
deoxygenation
is
highly
enabling
in
chemical
synthesis.
This
Review
covers
the
recent
methodology
development
carboxyl
deoxygenative
functionalizations,
highlighting
some
representative
significant
contributions
this
field.
These
advances
are
categorized
based
on
reactivity
patterns
oxygenated
feedstock
compounds,
including
aldehydes,
ketones
carboxylic
acids.
Four
types
reactive
intermediates
arising
from
aldehydes
during
deoxygenation,
namely,
bis-electrophiles,
carbenoids,
bis-nucleophiles
alkyl
radical
equivalents,
presented,
while
acids
mainly
behave
as
tris-electrophiles
when
deoxygenated.
In
each
subcategory,
selected
examples
organized
according
to
type
bond
formation
discussed
a
generalized
mechanistic
perspective.
Journal of the American Chemical Society,
Journal Year:
2020,
Volume and Issue:
142(30), P. 13011 - 13020
Published: June 27, 2020
Direct
conversion
of
aldehydes
and
ketones
into
alkylboronic
esters
via
deoxygenative
borylation
represents
an
unknown
yet
highly
desirable
transformation.
Herein,
we
present
a
one-step
metal-free
method
for
carbonyl
deoxy-borylation
under
mild
conditions.
A
wide
range
aromatic
are
tolerated
successfully
converted
the
corresponding
benzylboronates.
By
same
deoxygenation
manifold
with
aliphatic
ketones,
also
enable
concise
synthesis
1,1,2-tris(boronates),
family
compounds
that
currently
lack
efficient
synthetic
methods.
Given
its
simplicity
versatility,
expect
this
novel
approach
could
show
great
promise
in
organoboron
inspire
more
transformations
both
academic
industrial
settings.
Angewandte Chemie International Edition,
Journal Year:
2020,
Volume and Issue:
59(16), P. 6466 - 6472
Published: Jan. 23, 2020
Controlling
reaction
selectivity
is
a
permanent
pursuit
for
chemists.
Regioselective
catalysis,
which
exploits
and/or
overcomes
innate
steric
and
electronic
bias
to
deliver
diverse
regio-enriched
products
from
the
same
starting
materials,
represents
powerful
tool
divergent
synthesis.
Recently,
1,2-Markovnikov
hydroalkylation
of
1,3-dienes
with
simple
hydrazones
was
reported
generate
branched
allylic
compounds
when
nickel
catalyst
used.
As
part
effort,
shown
here
that
complete
switch
Markovnikov
anti-Markovnikov
addition
obtained
by
changing
ruthenium
catalyst,
thus
providing
direct
efficient
access
homoallylic
exclusively.
Isotopic
substitution
experiments
indicate
no
reversible
hydro-metallation
across
metal-π-allyl
system
occurred
under
catalysis.
Moreover,
this
protocol
applicable
regiospecific
distal
C=C
bond
1,3-enynes.
Chemical Science,
Journal Year:
2022,
Volume and Issue:
13(12), P. 3461 - 3467
Published: Jan. 1, 2022
Ruthenaelectro(
ii
/
iv
)-catalyzed
intermolecular
C–H
acyloxylations
of
oligopeptides
have
been
developed
by
the
guidance
key
experimental,
CV
and
computational
insights.
ACS Catalysis,
Journal Year:
2019,
Volume and Issue:
9(10), P. 9199 - 9205
Published: July 12, 2019
Hydroalkylation
of
unsaturated
hydrocarbons
with
unstabilized
carbon
nucleophiles
is
difficult
and
remains
a
major
challenge.
The
disclosed
examples
so
far
have
mainly
focused
on
the
involvement
heteroatom
and/or
stabilized
as
efficient
reaction
partners.
Reported
here
an
unprecedented
regioselective
nickel-catalyzed
hydrobenzylation
1,3-dienes
hydrazones,
generated
in
situ
from
abundant
aryl
aldehydes
ketones
acting
both
sources
carbanion
equivalent
hydride.
With
this
strategy,
terminal
sterically
hindered
internal
dienes
are
hydroalkylated
efficiently
highly
selective
manner,
thus
providing
reliable
catalytic
method
to
construct
challenging
C(sp3)–C(sp3)
bonds.
Nature Communications,
Journal Year:
2021,
Volume and Issue:
12(1)
Published: June 17, 2021
Aldehydes
and
ketones
are
widely
found
in
biomass
resources
play
important
roles
organic
synthesis.
However,
the
direct
deoxygenative
coupling
of
aldehydes
or
to
construct
C(sp3)-C(sp3)
bond
remains
a
scientific
challenge.
Here
we
report
nickel-catalyzed
reductive
homo-coupling
moisture-
air-stable
hydrazones
generated
in-situ
from
naturally
abundant
challenging
bond.
This
transformation
has
great
functional
group
compatibility
can
suit
broad
substrate
scope
with
innocuous
H2O,
N2
H2
as
by-products.
Furthermore,
application
several
biological
molecules
PEEK
model
demonstrate
generality,
practicability,
applicability
this
novel
methodology.
Chemical Science,
Journal Year:
2022,
Volume and Issue:
13(24), P. 7165 - 7171
Published: Jan. 1, 2022
A
visible-light-induced,
transition-metal
and
photosensitizer-free
cross-coupling
of
aryl
iodides
with
hydrazones
was
developed.
In
this
strategy,
were
used
as
alternatives
to
organometallic
reagents,
in
the
absence
a
transition
metal
or
an
external
photosensitizer,
making
mild
green.
The
protocol
compatible
variety
functionalities,
including
methyl,
methoxy,
trifluoromethyl,
halogen,
heteroaromatic
rings.
Mechanistic
investigations
showed
that
association
hydrazone
anion
halides
formed
electron
donor-acceptor
complex,
which
when
excited
visible
light
generated
radical
via
single-electron
transfer.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(49)
Published: Oct. 13, 2022
Abstract
We
describe
a
photo‐induced
reaction
for
the
in
situ
generation
of
highly
reactive
alkyl
diazo
species
from
carbonyl
precursors
via
photo‐excitation
N‐tosylhydrazone
anions.
The
intermediates
undergo
efficient
C−H
insertion
aldehydes,
leading
to
productive
synthesis
aldehydes
and
ketones.
method
is
applicable
iterative
densely
functionalized
compounds
through
sequential
trapping
with
various
aldehydes.
proceeds
without
need
any
catalyst
by
light
irradiation
features
high
functional
group
tolerance.
More
than
70
examples,
some
performed
on
gram‐scale,
demonstrate
broad
applicability
this
sequence
synthesis.
Chemical Science,
Journal Year:
2020,
Volume and Issue:
11(39), P. 10759 - 10763
Published: Jan. 1, 2020
A
palladium-catalyzed
hydroalkylation
of
methylenecyclopropanes
via
selective
C–C
σ-bond
scission
was
achieved,
in
which
simple
hydrazones
served
as
carbanion
equivalents.
This
method
affords
high
yields
C-alkylated
terminal
alkenes
with
good
functional
group
compatibility.
