Herein,
visible-light-induced
annulation
of
benzothioamides
with
sulfoxonium
ylides
to
furnish
thiazole
derivatives
is
developed
under
transition-metal-,
photocatalyst-,
and
oxidant-free
conditions.
This
protocol
exhibits
good
substrate
scope,
affording
the
desired
products
satisfied
yields
in
a
mild
green
manner.
Detailed
mechanistic
studies
suggest
that
benzothioamide
plays
dual
role
this
reaction.
Under
visible-light
irradiation,
excited
benzothioamide,
its
triplet
state,
could
undergo
S
attack
C═S
moiety
ylide
followed
by
dissociation
dimethyl
sulfoxide
H
migration
give
key
adduct.
In
addition,
act
as
an
organocatalyst
facilitate
intramolecular
cyclization
adduct
proton
transfer
steps.
After
dehydration
cyclized
intermediate,
can
be
produced.
Advanced Synthesis & Catalysis,
Год журнала:
2022,
Номер
364(24), С. 4440 - 4446
Опубликована: Дек. 2, 2022
Abstract
A
silver‐catalyzed
protocol
for
the
synthesis
of
3‐(1
H
‐isochromen)‐chromones
is
described.
The
method
involves
an
initial
6‐endo‐dig
cyclization
o
‐alkynylbenzaldehydes
and
domino
C−H
alkylation
chromone
annulation
‐hydroxyarylenaminones,
which
enables
installation
1
‐isochromen
in
a
single
structure.
This
synthetic
strategy
advantageous
excellent
regioselectivity,
step
economy,
concise
one‐pot
methodology,
gram‐scale
synthesis,
as
well
high
bond‐forming
efficiency.
magnified
image
Advanced Synthesis & Catalysis,
Год журнала:
2023,
Номер
365(8), С. 1217 - 1223
Опубликована: Март 25, 2023
Abstract
An
oxidative
[3+2+1]
cyclization
of
enaminones
and
N
‐alkenyl‐2‐pyrrolidinone
is
described
for
the
synthesis
4‐alkylated
1,4‐dihydropyridines
(1,4‐DHPs).
By
using
terminal
olefin
as
C4
source
1,4‐DHP
skeleton,
this
synthetic
strategy
provides
a
series
1,4‐DHPs
through
1,1‐difunctionalization/cyclization
process.
In
protocol,
two
C(
sp
3
)−C(
2
)
bonds
)−N
bond
are
simultaneously
formed,
hydrogen
on
newly
formed
methyl
group
skeleton
confirmed
possible
mechanism
proposed.
magnified
image
We
have
developed
a
mild
and
efficient
electrochemical
reduction
approach
employing
aryl
diazonium
salts
as
dual
synthons
to
synthesize
valuable
multi-substituted
pyrazoles
for
the
first
time.
Herein,
visible-light-induced
annulation
of
benzothioamides
with
sulfoxonium
ylides
to
furnish
thiazole
derivatives
is
developed
under
transition-metal-,
photocatalyst-,
and
oxidant-free
conditions.
This
protocol
exhibits
good
substrate
scope,
affording
the
desired
products
satisfied
yields
in
a
mild
green
manner.
Detailed
mechanistic
studies
suggest
that
benzothioamide
plays
dual
role
this
reaction.
Under
visible-light
irradiation,
excited
benzothioamide,
its
triplet
state,
could
undergo
S
attack
C═S
moiety
ylide
followed
by
dissociation
dimethyl
sulfoxide
H
migration
give
key
adduct.
In
addition,
act
as
an
organocatalyst
facilitate
intramolecular
cyclization
adduct
proton
transfer
steps.
After
dehydration
cyclized
intermediate,
can
be
produced.
