Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(43), P. 9288 - 9293
Published: Oct. 21, 2024
A
highly
regioselective
cobalt-catalyzed
three-component
alkyl
arylation
of
acrylates
with
iodides
and
aryl
Grignard
reagents
has
been
established.
The
reaction
efficiently
provides
an
alternative
strategy
for
the
construction
α-aryl
esters
a
broad
substrate
scope
good
yields
under
mild
conditions.
practical
applicability
this
protocol
is
shown
by
scaled-up
further
transformations
products.
In
addition,
preliminary
mechanistic
explorations
demonstrated
that
radicals
generated
efficient
cobalt
catalysis
are
instantaneously
added
to
finally
afford
desired
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
14(9), P. 6973 - 6980
Published: April 19, 2024
Development
of
photocatalytic
systems
that
facilitate
mechanistically
divergent
steps
in
complex
catalytic
manifolds
by
distinct
activation
modes
can
enable
previously
inaccessible
synthetic
transformations.
However,
multimodal
remain
understudied,
impeding
their
implementation
methodology.
We
report
herein
a
access
to
thiols
directly
merges
the
structural
diversity
carboxylic
acids
with
ready
availability
elemental
sulfur
without
substrate
preactivation.
The
transformation
provides
direct
radical-mediated
segue
one
most
biologically
important
and
synthetically
versatile
organosulfur
functionalities,
whose
accessibility
remains
largely
dominated
two-electron-mediated
processes
based
on
toxic
uneconomical
reagents
precursors.
two-phase
radical
process
is
facilitated
reactivity
acridine
photocatalysis
enables
both
singlet
excited
state
PCET-mediated
decarboxylative
carbon–sulfur
bond
formation
unknown
reductive
disulfur
cleavage
photoinduced
hydrogen
atom
transfer
silane–triplet
system.
study
points
significant
potential
providing
unexplored
directions
Journal of the American Chemical Society,
Journal Year:
2025,
Volume and Issue:
147(6), P. 4736 - 4742
Published: Jan. 31, 2025
The
preparation
of
alcohols
with
anti-Markovnikov
selectivity
directly
from
olefins
and
water
is
a
sought-after
reaction
due
to
its
atom-economy
potential
cost-effectiveness.
Herein,
we
present
the
first
general
method
for
direct,
catalytic
hydration
unconjugated
tri-
disubstituted
olefins.
key
advancement
made
possible
by
an
oxidative
(E*red
=
2.15
V)
N-H
acridinium
catalyst,
which
allowed
functionalization
alkenes
that
were
previously
unreactive
in
such
transformations
their
high
oxidation
potential.
developed
protocol
not
limited
but
also
enables
other
hydrofunctionalizations,
as
hydroetherifications,
following
same
mechanistic
pathway.
Organic Letters,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 14, 2025
Herein,
we
report
a
visible-light-driven
and
cobalt-mediated
1,4-hydroamination
reaction
of
1,3-dienes
with
arylmines
as
the
nucleophiles.
The
involves
regioselective
addition
[CoIII]–H
to
1,3-diene,
followed
by
oxidation
nucleophilic
substitution
amines.
Using
Ir(ppy)3
photocatalyst
enables
cobalt
redox
cycle
be
implemented
without
using
an
external
oxidant
hydride
regent.
This
protocol
can
applied
well
forge
carbon–oxygen
carbon–sulfur
bonds
in
analogous
way.
Chemical Science,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 1, 2025
An
applicable
cobalt-hydride-mediated
selective,
divergent
hydroetherification
and
sequential
hydroetherification/hydroarylation
of
1,3-dienes
with
simple
phenol
feedstocks
under
a
photoredox
cobalt
catalytic
system
have
been
developed.
A
variety
allyl
aryl
ethers
value-added
chroman
derivatives
can
be
obtained
in
good
to
excellent
yields
stereoselectivity.
This
method
not
only
obviates
the
need
for
extra
hydrosilanes
stoichiometric
oxidants,
thereby
offering
exceedingly
mild
conditions
alkene
hydroetherification,
but
also
represents
first
case
CoH-HAT-catalyzed
double
hydrofunctionalization
alkenes
sole
nucleophile.
The
continuous
selective
bond-forming
expands
applications
cobalt-hydride
MHAT
reaction
provides
novel
approach
design
synthesis
heterocyclic
molecules.
Development
of
photocatalytic
systems
that
facilitate
mechanistically
different
steps
in
complex
catalytic
manifolds
by
distinct
activation
modes
can
enable
previously
inaccessible
synthetic
transformations.
However,
multimodal
remain
understudied,
impeding
their
implementation
methodology.
We
report
herein
a
access
to
thiols
directly
merges
the
structural
diversity
carboxylic
acids
with
ready
availability
elemental
sulfur
without
substrate
preactivation.
The
transformation
provides
direct
radical-mediated
segue
one
most
biologically
important
and
synthetically
versatile
organosulfur
functionalities,
whose
accessibility
remains
largely
dominated
two-electron-mediated
processes
based
on
toxic
uneconomical
reagents
precursors.
two-phase
radical
process
is
facilitated
reactivity
acridine
photocatalysis
enables
both
singlet
excited
state
PCET-mediated
decarboxylative
carbon–sulfur
bond
formation
unknown
reductive
disulfur
cleavage
photoinduced
HAT
silane–triplet
system.
study
points
significant
potential
providing
new
directions
Chemistry - A European Journal,
Journal Year:
2024,
Volume and Issue:
30(58)
Published: Aug. 8, 2024
Abstract
Mild
and
inexpensive
copper‐catalyzed
aromatization‐driven
ring‐opening
amination
oxygenation
of
spiro
dihydroquinazolinones
are
presented,
respectively.
These
protocols
provide
facile
atom‐economical
access
to
the
aminated
carbonyl‐containing
quinazolin‐4(3
H
)‐ones
in
good
yields
with
functional
group
compatibility,
which
difficult
obtain
by
conventional
methods.
Remarkably,
a
telescoped
procedure
involving
condensation
ring‐opening/functionalization
for
simple
cycloalkanone
was
found
be
accessible.
Mechanistic
studies
suggest
radical
pathway
this
transformation.
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
14(19), P. 14574 - 14585
Published: Sept. 16, 2024
A
class
of
in-situ
generated
Lewis
acid
(LA)
activated
acridine
complexes
is
reported,
which
act
as
potent
photochemical
catalysts
for
the
oxidation
a
variety
protected
secondary
amines.
Acridine/LA
exhibit
tunable
excited
state
reduction
potentials
ranging
from
+2.07
to
2.38
V
vs.
SCE.
The
ytterbium
triflate
complex
3,6-di-t-butyl-9-mesitylacridine
catalyzes
Giese-type
reaction
Boc-protected
amines
with
challenging
conjugate
acceptors
such
acrylates,
that
are
inaccessible
analogous
acridinium
(t-Bu-Mes-Acr⊕)
catalyzed
reaction.
mechanism
this
was
investigated
using
suite
physical
organic
probes
including
intramolecular
13C
kinetic
isotope
effects
(KIEs),
variable
time
normalization
analysis
(VTNA)
kinetics,
determination
redox
potentials,
and
computational
studies.
In
by
t-Bu-Mes-Acr⊕,
mechanistic
studies
consistent
single-electron
transfer
(SET)
ground-state
reduced
t-Bu-Mes-Acr•
α-keto
radical
intermediate
first
irreversible
step
in
catalytic
cycle.
Intriguingly,
we
find
acridine/LA
better
ground
reductants
(-0.72
-0.74
vs
SCE)
relative
(-0.59
predict
increased
substrate
reactivity
stems
lower
energy
barrier
key
SET
event.
