ACS Catalysis,
Год журнала:
2024,
Номер
14(10), С. 8005 - 8012
Опубликована: Май 9, 2024
We
report
intra-
and
intermolecular
γ-amino
C(sp3)–H
functionalization
of
aliphatic
amines
using
a
vinylsulfone-based
HAT
(hydrogen
atom
transfer)
auxiliary
triple
catalysis,
which
is
composed
photoredox,
cobalt,
Brønsted
acid
catalysts
under
visible
light
irradiation.
The
process
accomplishes
four
elementary
steps:
(i)
electrophilic
carbon-centered
radical
formation
on
the
via
MHAT
(metal
hydride
hydrogen
reaction,
(ii)
generation
through
1,6-HAT
(iii)
single-electron
oxidation
to
carbocation
equivalents,
(iv)
nucleophilic
substitution
with
internal
or
external
nucleophiles.
As
result,
this
afforded
γ-amino-functionalized
products,
such
as
azetidines,
1,3-diamine,
1,3-aminoalcohol
derivatives.
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(20)
Опубликована: Фев. 16, 2022
Intermolecular
photocatalytic
hydroaminoalkylation
(HAA)
of
alkenes
have
emerged
as
a
powerful
method
for
the
construction
alkyl
amines.
Although
there
are
some
studies
aiming
at
stereoselective
HAA
reactions,
limited
to
electrophilic
alkenes.
Herein,
we
report
highly
regio-,
diastereo-,
and
enantioselective
electron-rich
dienol
ethers
α-amino
radicals
derived
from
acids
using
unified
photoredox
palladium
catalytic
system.
This
decarboxylative
1,2-Markovnikov
addition
enables
vicinal
amino
tertiary
with
high
levels
regio-
(up
>19
:
1
rr),
diastereo-
dr),
enantioselectivity
control
>99
%
ee).
Mechanistic
support
reversible
hydropalladation
key
step.
Chemical Communications,
Год журнала:
2022,
Номер
58(75), С. 10548 - 10551
Опубликована: Янв. 1, 2022
We
report
the
use
of
optofluidic
hollow-core
photonic
crystal
fibres
as
microreactors
for
Stern-Volmer
(SV)
luminescence
quenching
analysis
visible-light
photocatalytic
reactions.
This
technology
enables
measurements
on
nanolitre
volumes
and
paves
way
automated
SV
analyses
in
continuous
flow
that
minimise
catalyst
reagent
usage.
The
method
is
showcased
using
a
recently
developed
photoredox-catalysed
α-C-H
alkylation
reaction
unprotected
primary
alkylamines.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Янв. 31, 2024
Abstract
Primary
alkyl
amines
are
highly
reactive
in
N-nucleophilic
reactions
with
electrophiles.
However,
their
α-C−H
bonds
unreactive
towards
electrophiles
due
to
extremely
low
acidity
(p
K
a
~57).
Nonetheless,
1,8-diazafluoren-9-one
(DFO)
can
activate
primary
by
increasing
the
of
α-amino
C−H
up
10
44
times.
This
makes
acidic
enough
be
deprotonated
under
mild
conditions.
By
combining
DFO
an
iridium
catalyst,
direct
asymmetric
alkylation
NH
2
-unprotected
allylic
carbonates
has
been
achieved.
reaction
produces
wide
range
chiral
homoallylic
high
enantiopurities.
The
approach
successfully
switched
reactivity
between
and
from
intrinsic
amination
alkylation,
enabling
construction
pharmaceutically
significant
readily
available
single
step.
ACS Catalysis,
Год журнала:
2024,
Номер
14(10), С. 8005 - 8012
Опубликована: Май 9, 2024
We
report
intra-
and
intermolecular
γ-amino
C(sp3)–H
functionalization
of
aliphatic
amines
using
a
vinylsulfone-based
HAT
(hydrogen
atom
transfer)
auxiliary
triple
catalysis,
which
is
composed
photoredox,
cobalt,
Brønsted
acid
catalysts
under
visible
light
irradiation.
The
process
accomplishes
four
elementary
steps:
(i)
electrophilic
carbon-centered
radical
formation
on
the
via
MHAT
(metal
hydride
hydrogen
reaction,
(ii)
generation
through
1,6-HAT
(iii)
single-electron
oxidation
to
carbocation
equivalents,
(iv)
nucleophilic
substitution
with
internal
or
external
nucleophiles.
As
result,
this
afforded
γ-amino-functionalized
products,
such
as
azetidines,
1,3-diamine,
1,3-aminoalcohol
derivatives.
