European Journal of Organic Chemistry,
Год журнала:
2023,
Номер
27(3)
Опубликована: Ноя. 6, 2023
Abstract
A
cobalt‐catalyzed
annulation
of
o
‐phenylenediamines
and
internal
alkynes
for
the
synthesis
quinoxalines
is
developed.
This
method
provides
a
variety
in
good
to
high
yields
under
simple
mild
reaction
conditions
with
molecular
O
2
as
terminal
oxidant.
Preliminary
mechanistic
studies
show
that
novel
mechanism
involved
current
reaction,
which
different
from
previous
reported
dicarbonyl
compound
via
oxidation
alkyne.
Chemical Reviews,
Год журнала:
2024,
Номер
124(3), С. 1122 - 1246
Опубликована: Янв. 2, 2024
Dearomatization
reactions
have
become
fundamental
chemical
transformations
in
organic
synthesis
since
they
allow
for
the
generation
of
three-dimensional
complexity
from
two-dimensional
precursors,
bridging
arene
feedstocks
with
alicyclic
structures.
When
those
processes
are
applied
to
pyridines,
quinolines,
and
isoquinolines,
partially
or
fully
saturated
nitrogen
heterocycles
formed,
which
among
most
significant
structural
components
pharmaceuticals
natural
products.
The
inherent
challenge
lies
low
reactivity
heteroaromatic
substrates,
makes
dearomatization
process
thermodynamically
unfavorable.
Usually,
connecting
event
irreversible
formation
a
strong
C–C,
C–H,
C–heteroatom
bond
compensates
energy
required
disrupt
aromaticity.
This
aromaticity
breakup
normally
results
1,2-
1,4-functionalization
heterocycle.
Moreover,
combination
these
subsequent
tandem
stepwise
protocols
allows
multiple
heterocycle
functionalizations,
giving
access
complex
molecular
skeletons.
aim
this
review,
covers
period
2016
2022,
is
update
state
art
nucleophilic
dearomatizations
showing
extraordinary
ability
dearomative
methodology
indicating
their
limitations
future
trends.
Organic Letters,
Год журнала:
2022,
Номер
24(40), С. 7372 - 7377
Опубликована: Сен. 29, 2022
Herein,
a
B2pin2-mediated
radical
cascade
cyclization/aromatization
reaction
of
enaminone
with
pyridine
is
described.
This
strategy
provides
practical
way
for
the
construction
valuable
functionalized
indolizines
under
metal-,
external
oxidant-,
and
base-free
conditions,
which
could
be
compatible
various
kinds
functional
groups,
such
as
halogen,
π-system,
heterocycle,
ferrocenyl,
etc.
A
preliminary
mechanism
investigation
indicated
that
pyridine-boryl
formed
in
situ
triggered
to
occur.
Organic Letters,
Год журнала:
2023,
Номер
25(5), С. 838 - 842
Опубликована: Янв. 27, 2023
A
copper-catalyzed
annulation
of
O-acyl
oximes
with
cyclic
1,3-diones
has
been
developed
for
the
concise
synthesis
7,8-dihydroindolizin-5(6H)-ones
and
cyclohexanone-fused
furans
through
substituent-controlled
selective
radical
coupling
process.
2-Alkyl
undergo
C-C
coupling,
while
2-unsubstituted
C-O
coupling.
Organic Letters,
Год журнала:
2023,
Номер
25(7), С. 1192 - 1197
Опубликована: Фев. 13, 2023
A
cost-effective,
highly
regioselective
and
metal-free
version
for
the
synthesis
of
indolizine
derivatives
by
means
Tf2O-mediated
cascade
reaction
pyridyl-enaminones
thiophenols/thioalcohols
under
mild
conditions
has
been
reported.
Diverse
electron-rich
could
be
obtained
in
up
to
94%
yield
via
selective
1,4-addition
vinyl
iminium
triflate
tandem
cyclization/aromatization,
which
allowed
simultaneous
construction
C–N
C–S/and
one
example
C–Se
bonds.
Organic Letters,
Год журнала:
2022,
Номер
24(21), С. 3828 - 3833
Опубликована: Май 23, 2022
A
copper-catalyzed
annulation
of
α,β-unsaturated
O-acyl
ketoximes
with
isoquinolinium
N-ylides
has
been
developed
for
the
concise
synthesis
stable
N-H
imines
a
benzo[7,8]indolizine
core.
When
β-(2-bromoaryl)-α,β-unsaturated
are
used
as
starting
materials,
cascade
cyclization
occurs
to
afford
benzo[7,8]indolizino[1,2-c]quinolines.
An
iron-catalyzed
double
annulation
of
O-acyl
oximes
with
fumaronitrile
has
been
developed
for
the
concise
synthesis
polysubstituted
4-cyano-7-azaindoles.
This
method
enables
construction
two
fused
heterocycles
in
a
one-step
reaction
using
readily
available
starting
materials
under
redox-neutral
conditions.
Chemical Communications,
Год журнала:
2022,
Номер
58(47), С. 6757 - 6760
Опубликована: Янв. 1, 2022
A
novel
route
for
tandem
C-N/C-O
formation
via
copper-catalyzed
[4+2]
oxidative
annulation
of
α,β-unsaturated
ketoxime
acetates
with
ethyl
trifluoropyruvate
to
synthesize
valuable
trifluoromethyl-containing
2H-1,3-oxazines
in
moderate
good
yields
is
developed.
This
procedure
represents
the
first
oxime
derivatives
activated
CO
bonds
and
provides
an
alternative
towards
functionalized
2H-1,3-oxazines.
