ChemCatChem,
Journal Year:
2023,
Volume and Issue:
16(2)
Published: Nov. 17, 2023
The
metal-hydride
hydrogen
atom
transfer
(MHAT)
method
is
widely
recognized
as
a
powerful
technique
for
functionalizing
alkenes.
However,
its
application
in
the
functionalization
of
industrial
feedstock
dienes
and
allenes
relatively
rare
due
to
challenges
related
chemo-selectivity.
In
recent
studies,
Co-porphines
have
been
identified
highly
efficient
catalysts
under
photoirradiation
MHAT,
demonstrating
an
exceptional
level
chemoselectivity
allenes,
while
disregarding
other
simple
olefins
present.
This
novel
enables
selective
reductive
coupling
pyridines
with
allylation
aldehydes
by
combination
Ti
catalysis.
Mechanistic
studies
density
functional
theory
(DFT)
calculations
support
idea
that
non-reversible
atoms
from
cobalt
hydride
leading
generation
allyl
radicals,
key
step
catalytic
cycle.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(41)
Published: May 15, 2023
Catalytic
hydrogen
atom
transfer
from
metal-hydrides
to
alkenes
allows
feedstock
olefins
be
used
as
alkyl
radical
precursors.
The
chemoselectivity
of
this
process
makes
it
an
attractive
synthetic
tool
and
such
has
been
regularly
in
synthesis
complex
molecules.
However,
onwards
reactivity
is
limited
by
compatibility
with
the
conditions
which
form
key
metal-hydride
species.
Now,
through
merger
photocatalysis
or
electrochemistry,
milder
methods
are
emerging
can
unlock
entirely
new
offer
perspectives
on
expanding
these
unprecedented
directions.
This
review
outlines
most
recent
developments
electro-
photochemical
cobalt
catalysed
offers
suggestions
future
outlook.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(45)
Published: Sept. 12, 2023
Despite
widespread
use
of
the
deuterium
isotope
effect,
selective
labeling
chemical
molecules
remains
a
major
challenge.
Herein,
facile
and
general
electrochemically
driven,
organic
mediator
enabled
deuteration
styrenes
with
oxide
(D2
O)
as
economical
source
was
reported.
Importantly,
this
transformation
could
be
suitable
for
various
electron
rich
mediated
by
triphenylphosphine
(TPP).
The
reaction
proceeded
under
mild
conditions
without
transition-metal
catalysts,
affording
desired
products
in
good
yields
excellent
D-incorporation
(D-inc,
up
to
>99
%).
Mechanistic
investigations
means
experiments
cyclic
voltammetry
tests
provided
sufficient
support
transformation.
Notably,
method
proved
powerful
tool
late-stage
biorelevant
compounds.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(19)
Published: Feb. 28, 2024
Abstract
We
report
a
general,
intramolecular
cycloisomerization
of
unactivated
olefins
with
pendant
nucleophiles.
The
reaction
proceeds
under
mild
conditions
and
tolerates
ethers,
esters,
protected
amines,
acetals,
pyrazoles,
carbamates,
arenes.
It
is
amenable
to
N
‐,
O
as
well
C
‐nucleophiles,
yielding
number
different
heterocycles
including,
but
not
limited
to,
pyrrolidines,
piperidines,
oxazolidinones,
lactones.
Use
both
benzothiazinoquinoxaline
organophotocatalyst
Co‐salen
catalyst
obviates
the
need
for
stoichiometric
oxidant
or
reductant.
showcase
utility
protocol
in
late‐stage
drug
diversification
synthesis
several
small
natural
products.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(9)
Published: Jan. 10, 2023
Prospects
in
light-driven
water
activation
have
prompted
rapid
progress
hydrogenation
reactions.
We
describe
a
Ni2+
-N4
site
built
on
carbon
nitride
for
catalyzed
semihydrogenation
of
alkynes,
with
supplying
protons,
powered
by
visible-light
irradiation.
Importantly,
the
photocatalytic
approach
developed
here
enabled
access
to
diverse
deuterated
alkenes
D2
O
excellent
deuterium
incorporation.
Under
irradiation,
evolution
four-coordinate
species
into
three-coordinate
Ni+
was
spectroscopically
identified.
In
combination
theoretical
calculations,
photo-evolved
is
posited
as
HO-Ni+
-N2
an
uncoordinated,
protonated
pyridinic
nitrogen,
formed
coupled
reduction
and
dissociation.
The
paired
Ni-N
prompts
hydrogen
liberation
from
water,
it
renders
desorption
alkene
preferred
over
further
alkane,
ensuring
selectivity.
Chinese Journal of Chemistry,
Journal Year:
2023,
Volume and Issue:
42(10), P. 1145 - 1156
Published: Dec. 26, 2023
Comprehensive
Summary
The
deuteration
of
organic
compounds
has
attracted
more
attentions
in
recent
years
for
the
potential
applications
new
drug
discovery
and
synthetic
chemistry.
For
this
purpose,
many
efficient
deuterium
labeling
methodologies
have
been
developed,
including
hydrogen
isotope
exchange
(HIE),
reductive
deuteration,
dehalogenative
that
allow
synthesis
selectively
deuterated
compounds.
In
last
few
years,
great
breakthroughs
selective
achieved
interest
molecules
is
rising.
review,
we
summarized
developments
since
2021.
Several
types
key
processes
incorporation
reactions,
H/D
exchange,
are
introduced
discussed.
Key
Scientists
2000s,
Derdau
Atzrodt's
group
made
contributions
to
directing
assisted
noble‐metal
catalyzed
arenes
labeled
During
same
period,
Sajiki
co‐workers
completed
a
series
reactions
by
heterogeneous
platinum‐group
metal
catalysts.
Since
2015,
Gregory
Pieters
developed
ruthenium
catalysts
exchange.
2016,
Chirik's
presence
homogeneous
iron
complex.
David
MacMillan
coworkers
photocatalyzed
HIE
α‐amino
C(sp
3
)–H
bonds.
From
2020,
nanoelectrodes
were
designed
deuterations
unactivated
unsaturated
bonds
Zhang's
group.
Recently,
Beller's
several
strategies
isotopic
using
earth‐abundant
Our
review
latest
important
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(24)
Published: April 12, 2023
Catalytic
metal
hydride
hydrogen
atom
transfer
(MHAT)
reactions
have
proven
to
be
a
powerful
method
for
alkene
functionalization.
This
work
reports
the
discovery
of
Co-porphines
as
highly
efficient
MHAT
catalysts
with
loading
only
0.01
mol
%
unprecedented
chemoselective
allene
functionalization
under
photoirradiation.
Moreover,
newly
developed
bimetallic
strategy
by
combination
photo
Co-MHAT
and
Ti
catalysis
enabled
successful
carbonyl
allylation
wide
range
amino,
oxy,
thio,
aryl,
alkyl-allenes
providing
expedient
access
valuable
β-functionalized
homoallylic
alcohols
in
over
100
examples
exceptional
regio-
diastereoselectivity.
Mechanism
studies
DFT
calculations
supported
that
selectively
transferring
atoms
from
cobalt
allenes
generating
allyl
radicals
is
key
step
catalytic
cycle.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(45)
Published: Sept. 7, 2023
Abstract
Selective
hydroarylation
of
dienes
has
potential
to
provide
swift
access
useful
building
blocks.
However,
most
existing
methods
rely
on
stabilised
by
an
aromatic
group
and
transmetallation
or
nucleophilic
attack
steps
require
electron‐rich
aryl
coupling
partners.
As
such,
there
are
few
examples
which
tolerate
wide‐spread
heteroarenes
such
as
pyridine.
Whilst
allylic
C−H
functionalisation
could
be
considered
alternative
approach,
the
positional
selectivity
unsymmetrical
substrates
is
hard
control.
Here,
we
report
a
general
approach
for
selective
hydropyridylation
under
mild
conditions
using
metal
catalysed
hydrogen‐atom
transfer.
Photoinduced,
reductive
enable
simultaneous
formation
cobalt‐hydride
catalyst
persistent
radical
easily‐synthesised
pyridyl
phosphonium
salts.
This
facilitates
in
traceless
manner
at
C4‐position
wide‐range
pyridine
substrates.
The
mildness
method
underscored
its
functional‐group
tolerance
demonstrated
applications
late‐stage
functionalisation.
Based
combination
experimental
computational
studies,
propose
mechanistic
pathway
proceeds
through
non‐reversible
transfer
(HAT)
from
cobalt
hydride
species
uniquely
presence
other
olefins
due
much
higher
relative
barrier
associated
with
olefin
HAT.
The
use
of
magnesium
and
methanol
in
the
reduction
various
functional
groups
has
been
well
established.
In
this
study,
we
present
a
reductive
deuteration
system
using
Mg/CH
ACS Nanoscience Au,
Journal Year:
2025,
Volume and Issue:
5(1), P. 52 - 59
Published: Jan. 7, 2025
Heavy
water
(D2O)
has
found
extensive
application
as
a
moderator
in
nuclear
reactors.
Additionally,
it
serves
substitute
for
regular
(H2O)
biological
or
spectroscopic
experiments,
providing
deuterium
source
and
addressing
challenges
related
to
solvent
opacity
contrast.
This
is
particularly
relevant
experiments
involving
neutron
scattering,
infrared
absorption,
magnetic
resonance.
However,
replacing
H2O
with
D2O
not
always
straightforward
harmless
substitution
can
instead
have
unintended
chemical
consequences.
In
this
study,
we
highlight
the
significant
impact
of
deuteration
on
two
common
gold
nanoparticle
syntheses-borohydride
reduction
ascorbic
acid
reduction-by
comparing
reactions
mixtures
thereof.
The
resulting
colloids
exhibit
differences
size
spectral
characteristics,
their
effectiveness
nanocatalysts
widely
used
4-nitrophenol
benchmark
reaction
adversely
affected
by
presence
during
both
particle
synthesis
catalytic
medium.
Ultimately,
these
results
underscore
critical
awareness
often
overlooked
scientists
engineers:
despite
its
widespread
sometimes
indispensable
use
analytical
spectroscopy,
cellular
imaging,
biophysics,
organic
chemistry,
cannot
truly
replace
without
significantly
altering
environment
reaction.