Advanced Synthesis & Catalysis,
Год журнала:
2022,
Номер
365(1), С. 23 - 30
Опубликована: Дек. 20, 2022
Abstract
We
developed
a
cost‐effective
cobalt‐catalyzed
electrochemical
annulation
to
generate
diversified
novel
complex
dihydroisoquinolin
derivatives
from
amides
and
alkenes
in
simple
maneuverable
undivided
cell.
The
reaction
proceeded
C−H/N−H
activation,
the
catalyst
was
regenerated
by
anodic
oxidation.
Notably,
strategy
of
electrocatalysis
avoided
consumption
stoichiometric
chemical
oxidants.
magnified
image
ACS Catalysis,
Год журнала:
2024,
Номер
14(12), С. 9294 - 9301
Опубликована: Июнь 4, 2024
A
cobalt-catalyzed
hydroalkynylation
of
alkenes
with
alkynyl
trifluoroborates
is
described,
proceeding
through
a
cobalt
hydride-mediated
radical-polar
crossover
metal
hydrogen-atom-transfer
process.
This
method
affords
structurally
diverse
alkynyl-containing
compounds
in
high
yields
under
mild
conditions
and
features
wide
substrate
scope,
good
functional
group
tolerance,
suitability
for
late-stage
functionalization
relatively
complex
natural
products
bioactive
molecules.
Expanding
the
scope
to
alkenyltrifluoroborate
salts
further
increases
utility
developed
methodology.
approach
paves
an
alternative
route
radical-involved
alkynylation
alkenylation
reactions
nucleophilic
alkynyl/alkenyl
reagents.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(46)
Опубликована: Авг. 6, 2024
Abstract
A
cobalt‐catalyzed
intramolecular
Markovnikov
hydroalkoxycarbonylation
and
hydroaminocarbonylation
of
unactivated
alkenes
has
been
developed,
enabling
highly
chemo‐
regioselective
synthesis
α
‐alkylated
γ
‐lactones
‐lactams
in
good
yields.
The
mild
reaction
conditions
allow
use
mono‐,
di‐
trisubstituted
bearing
a
variety
functional
groups.
Preliminary
mechanistic
studies
suggest
the
proceeds
through
CO‐mediated
hydrogen
atom
transfer
(HAT)
radical‐polar
crossover
(RPC)
process,
which
cationic
acylcobalt(IV)
complex
is
proposed
as
key
intermediate.
We
report
intramolecular
photocatalyzed
cycloisomerization
of
unactivated
olefins
with
pendant
nucleophiles.
The
reaction
proceeds
under
mild
conditions
and
utilizes
guanidines,
ureas,
isoureas,
isothioureas,
carbonates
to
yield
several
different
five-,
six-,
seven-membered
heterocycles.
Use
benzothiazinoquinoxaline
as
an
organophotocatalyst
cobalt–salen
catalyst
obviates
the
need
for
a
stoichiometric
oxidant
or
reductant.
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.
The
intermolecular
hydroamination
of
unactivated
alkenes
with
simple
amines
continues
to
be
an
attractive
and
challenging
undertaking
in
organic
synthesis.
current
state-of-the-art
strategies
for
photocatalyzed
usually
commence
the
formation
a
C–N
bond,
thereby
delivering
exclusively
anti-Markovnikov
products.
We
herein
reported
facile
mild
Markovnikov
anilines
through
photoredox
cobalt-catalyzed
hydrogen
atom
transfer
followed
by
radical-polar
crossover
nucleophilic
amination
process.
reaction
features
wide
substrate
scope,
good
functional
group
tolerance,
excellent
yields.
Application
this
late-stage
functionalization
relatively
complex
natural
products
bioactive
molecules
further
increases
utility
developed
methodology.
Organic Chemistry Frontiers,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
A
bifunctional
iron-mediated
multicomponent
reaction
for
Markovnikov-selective
hydrothiolation
of
alkenes
has
been
established.
The
involves
an
hydrogen
atom
transfer
and
a
single
electron
process.
JACS Au,
Год журнала:
2022,
Номер
2(5), С. 1071 - 1077
Опубликована: Май 6, 2022
The
cycloisomerization
of
β-,
γ-,
and
δ-unsaturated
N-acyl
sulfonamides
to
N-sulfonyl
lactams
imidates
is
reported.
This
transformation
effected
in
the
presence
a
CoIII(salen)
catalyst
using
t-BuOOH
or
air
as
oxidant.
method
shows
good
functional
group
tolerance
(alkyl,
aryl,
heteroaryl,
ether,
N-Boc)
furnishes
an
underexplored
class
cyclic
building
blocks.
strong
solvent
dependence
investigated,
synthetic
versatility
imidate
product
highlighted.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(5), С. 3277 - 3281
Опубликована: Фев. 21, 2023
Described
here
is
a
method
for
intermolecular
hydroalkoxylation
and
hydrocarboxylation
of
2-azadienes
through
cobalt-catalyzed
hydrogen
atom
transfer
oxidation.
This
protocol
provides
source
2-azaallyl
cation
equivalents
under
mild
conditions,
chemoselective
in
the
presence
other
C═C
double
bonds,
requires
no
excess
amount
added
alcohol
or
oxidant.
Mechanistic
studies
suggest
that
selectivity
arises
from
lowering
transition
state
leads
to
highly
stabilized
radical.
