The
present
study
reports
an
asymmetric
NHC-catalyzed
formal
[4+2]
cycloaddition
of
heterocyclic
alkenes
containing
polarized
double
bond
with
azolium-dienolate
intermediate
generated
from
α-bromo-α,β-unsaturated
aldehydes
without
external
oxidation
Breslow
intermediate.
Heterocyclic
cyclohexenones
were
produced
in
good
isolated
yields
(typically
about
90%)
stereochemical
outcomes
dr
>
20/1,
and
70-99%
ee).
synthetic
utility
the
protocol
was
exemplified
by
scope
alkenes.
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
89(6), С. 4067 - 4073
Опубликована: Фев. 23, 2024
We
describe
herein
an
N-heterocyclic-carbene-catalyzed
atroposelective
synthesis
of
axially
chiral
diaryl
ethers.
Through
a
sequentially
enantioselective
desymmetric
process
and
kinetic
resolution
process,
the
products
could
be
constructed
in
good
yields
with
excellent
enantiopurities.
Both
alcohols
phenols
were
compatible
this
catalytic
system.
The
carboxylic
acids
derived
from
esters
proven
to
potential
ligands
for
asymmetric
synthesis,
example,
Rh(III)-catalyzed
C–H
functionalization.
The Chemical Record,
Год журнала:
2023,
Номер
23(7)
Опубликована: Март 21, 2023
Abstract
N
‐Heterocyclic
carbene
(NHC)
organocatalysis
has
emerged
as
a
powerful
tool
in
the
field
of
modern
organic
synthesis
especially
asymmetric
construction
various
cyclic
skeletons.
As
an
emerging
NHC‐bound
1,3‐bielectrophilic
intermediate,
alkynyl
acylazolium
drawn
substantial
attention
recent
years,
and
been
used
versatile
3C‐synthon
synthesizing
valuable
molecules
since
its
discovery.
In
this
review,
focused
on
different
pathways
for
formation
acylazoliums
from
precursors
like
alkynoic
esters,
acids
ynals,
advances
transformations
applications
pioneered
or
developed
over
last
decade
under
NHC‐catalysis
were
summarized
comprehensively.
At
same
time,
outlook
further
investigation
exploration
novel
reaction
modes
future
was
also
discussed.
European Journal of Organic Chemistry,
Год журнала:
2023,
Номер
26(48)
Опубликована: Окт. 11, 2023
Abstract
N
‐Heterocyclic
carbene
(NHC)
catalyzed
radical‐radical
reactions
have
been
proven
to
be
powerful
strategies
for
assembling
ketyl‐containing
compounds
via
single
electron
transfer
(SET)
pathway
under
either
thermal
conditions
or
photoredox
conditions.
In
this
context,
acylation
of
alkenes
radical
relay
NHC‐organocatalysis
has
also
opened
a
new
window
the
difunctionalization
construct
valuable
molecules
in
organic
synthesis.
review,
advances
and
progress
were
summarized
according
different
ways
generation
key
NHC‐bound
ketyl‐type
radicals.
Furthermore,
reaction
scopes,
limitations
mechanisms
discussed
based
on
types
catalytic
systems.
Conclusions
perspectives
put
forward
at
end.
The Chemical Record,
Год журнала:
2023,
Номер
23(7)
Опубликована: Янв. 26, 2023
Abstract
Over
the
last
ten
years,
combination
of
organocatalysis
with
transition
metal
(TM)
catalysis
has
become
one
most
important
toolboxes
used
for
synthesizing
optically
pure
compounds
containing
chiral
quaternary
centers,
including
spiro
heterocyclic
molecules.
The
dominant
method
in
enantioselective
synthesis
based
on
synergistic
includes
aminocatalysis
and
NHC
catalysis,
as
already
established
covalent
organocatalytic
strategies.
Another
area
widely
combined
TM
producing
enantiomerically
enriched
is
non‐covalent
dominated
by
phosphoric
acids,
thiourea,
squaramide
derivatives.
This
review
article
aims
to
summarize
methods
constructing
spirocyclic
heterocycles
a
catalysis.
Chemistry - An Asian Journal,
Год журнала:
2024,
Номер
19(9)
Опубликована: Март 7, 2024
N-Heterocyclic
carbenes
(NHCs)
catalysts
have
been
employed
as
effective
tools
in
the
development
of
various
reactions,
which
made
notable
contributions
developing
diverse
reaction
modes
and
generating
significant
functionalized
molecules.
This
review
provides
an
overview
recent
advancements
chemo-
regioselective
activation
different
aldehydes
using
NHCs,
categorized
into
five
parts
based
on
modes.
A
brief
conclusion
outlook
is
provided
to
stimulate
novel
for
accessing
functional
Organic Letters,
Год журнала:
2024,
Номер
26(17), С. 3552 - 3556
Опубликована: Апрель 19, 2024
A
formal
[3
+
2]
annulation
of
cyclohexadienone-tethered
ynals
is
enabled
by
an
N-heterocyclic
carbene
(NHC)
catalyst,
affording
a
tricyclo[6.2.1.04,11]undecane
framework.
This
study
represents
the
first
demonstration
using
C═C
double
bonds
as
reaction
partner
in
NHC-catalyzed
ynals.
strategy
characterized
mild
conditions
and
100%
atom
economy
well
high
catalytic
performance
efficiency.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(15), С. 11299 - 11309
Опубликована: Июль 14, 2023
An
N-heterocyclic
carbene-catalyzed
atroposelective
[3
+
3]
annulation
of
enals
with
2-aminomaleate
derivatives
is
described.
A
series
substituted
dihydropyridones
bearing
both
C-N
axis
and
point
chirality
were
synthesized
good
diastereo-
enantioselectivity
under
mild
conditions.
This
efficient
strategy
successfully
superpositions
an
extra
chiral
element
axial
backbone,
the
generated
structurally
interesting
atropisomers
may
have
potential
application
in
drug
discovery.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(23), С. 16621 - 16632
Опубликована: Ноя. 15, 2023
An
enantioselective
construction
of
pyrazolo[3,4-b]pyridones
was
achieved
via
N-heterocyclic
carbene-catalyzed
[3
+
3]
annulation
enals
with
5-aminopyrazoles.
This
protocol
not
only
offers
a
highly
efficient
synthetic
approach
for
the
preparation
various
substituted
but
also
provides
an
effective
method
rapid
synthesis
enantiopure
spirooxindone
derivatives.
