Advanced Synthesis & Catalysis,
Год журнала:
2021,
Номер
363(16), С. 4047 - 4053
Опубликована: Июнь 30, 2021
Abstract
An
organocatalyzed
asymmetric
dearomative
[3+2]
annulation
reaction
of
electron‐deficient
2‐nitrobenzo
heteroarenes
including
2‐nitrobenzofurans,
2‐nitrobenzothiophenes
and
2‐nitroindoles
with
3‐isothiocyanato
oxindoles
was
developed.
With
a
multiple
hydrogen‐bonding
bifunctional
thiourea
as
the
catalyst,
displays
broad
substrate
scope
provides
an
access
to
structurally
diverse
polycyclic
spirooxindoles
containing
three
contiguous
stereogenic
centers
in
high
yields
good
diastereo‐
enantioselectivities
(up
99%
yield,
94:6
dr,
97%
ee).
This
organocatalysis
protocol
is
able
afford
products
complementarily
diastereoselectivity
versus
previous
work
transition
metal
catalysis.
magnified
image
Chemical Communications,
Год журнала:
2020,
Номер
56(17), С. 2586 - 2589
Опубликована: Янв. 1, 2020
An
efficient
enantioselective
dearomatization
of
2-nitrobenzofurans
was
realized
via
an
organocatalyzed
one-step
Michael
addition
process.
This
method
provides
a
facile
strategy
to
access
range
structurally
diverse
3,3'-disubstituted
oxindoles,
which
feature
intriguing
combination
two
privileged
motifs
including
3-pyrrolyl-substituted-oxindoles
and
2,3-dihydrobenzofurans
substructures,
in
excellent
results.
Organic Letters,
Год журнала:
2020,
Номер
22(8), С. 3114 - 3118
Опубликована: Апрель 7, 2020
A
sequential
[4
+
2]/[2
1]
annulation
of
α-aryl
vinylsulfoniums
with
2-aminochalcones
and
2-(2-aminobenzylidene)-1H-indene-1,3(2H)-dione
is
reported
that
affords
a
series
cyclopropane-fused
tetrahydroquinolines.
The
salient
features
this
novel
practical
transformation
include
high
efficiency,
transition-metal-free
nature,
operational
simplicity,
outstanding
functional
group
tolerance.
Beilstein Journal of Organic Chemistry,
Год журнала:
2021,
Номер
17, С. 2585 - 2610
Опубликована: Окт. 18, 2021
Nitrogen-containing
scaffolds
are
ubiquitous
in
nature
and
constitute
an
important
class
of
building
blocks
organic
synthesis.
The
asymmetric
aza-Michael
reaction
(aza-MR)
alone
or
tandem
with
other
reaction(s)
is
synthetic
tool
to
form
new
C–N
bond(s)
leading
developing
libraries
diverse
types
bioactive
nitrogen
compounds.
synthesis
application
a
variety
organocatalysts
for
accomplishing
highly
useful
syntheses
without
causing
environmental
pollution
compliance
‘Green
Chemistry”
has
been
landmark
development
the
recent
past.
Application
many
these
extended
aza-MR
during
last
two
decades.
present
article
overviews
literature
published
10
years
concerning
amines
amides
catalysed
by
organocatalysts.
Both
organocatalysts,
i.e.,
those
acting
through
non-covalent
interactions
working
covalent
bond
formation
have
applied
aza-MR.
Thus,
review
includes
examples
wherein
cinchona
alkaloids,
squaramides,
chiral
amines,
phase-transfer
catalysts
bifunctional
thioureas
used,
which
activate
substrates
hydrogen
formation.
Most
reactions
accompanied
high
yields
enantiomeric
excesses.
On
hand,
N-heterocyclic
carbenes
pyrrolidine
derivatives
such
as
iminium
ions
also
included.
Wherever
possible,
comparison
made
between
efficacies
various
European Journal of Organic Chemistry,
Год журнала:
2022,
Номер
2022(18)
Опубликована: Апрель 5, 2022
Abstract
Dearomatization
reactions
employing
simple
aromatic
compounds
have
showcased
remarkable
progress
in
the
recent
decade
and
emerged
as
one
of
most
straightforward
powerful
tools
for
creation
highly
functionalized,
three‐dimensional
molecular
frameworks
commonly
encountered
medicinal
chemistry
life
sciences.
Among
use,
nitro(hetero)arenes,
which
feature
a
less
pronounced
character
due
to
presence
electron‐withdrawing
nitro
group,
been
extensively
used
different
types
dearomatization
reactions.
The
dearomative
annulation
reaction
serves
versatile
method
construction
complex
polycyclic
systems.
This
overview
presents
brief
summary
impressive
advances
nitro(hetero)arenes
provides
some
inspirations
future
research.
Organic Letters,
Год журнала:
2024,
Номер
26(13), С. 2623 - 2628
Опубликована: Март 24, 2024
An
efficient
dearomative
cyclization
of
2-nitrobenzofurans
via
a
thiol-triggered
tandem
Michael
addition/intramolecular
Henry
reaction
has
been
developed.
A
range
thiochromeno[3,2-b]benzofuran-11-ols
and
tetrahydrothieno[3,2-b]benzofuran-3-ols
could
be
obtained
in
up
to
99%
yield
>20:1
dr.
The
valuable
thiochromone
fused
benzofurans
prepared
with
the
2-mercaptobenzaldehyde
reaction/rearomatization/oxidative
dehydrogenation
process
one-pot
two-step
operation.
mechanism
for
was
tentatively
proposed.
Organic & Biomolecular Chemistry,
Год журнала:
2019,
Номер
17(21), С. 5294 - 5304
Опубликована: Янв. 1, 2019
An
efficient
Ph2PMe-catalyzed
dearomative
(3
+
2)
annulation
of
2-nitrobenzofurans,
2-nitrobenzothiophenes,
and
3-nitrobenzothiophenes
with
allenoates
is
reported.
Organic Letters,
Год журнала:
2020,
Номер
22(18), С. 7088 - 7093
Опубликована: Авг. 28, 2020
The
first
catalytic
enantioselective
dearomatization/rearomatization
of
2-nitroindoles
triggered
by
the
Michael
addition
3-monosubstituted
oxindoles
was
established.
A
wide
range
3-indolyl-3'-alkyloxindoles
(up
to
99%
yield,
97%
ee)
and
3-indolyl-3'-aryloxindoles
95%
were
obtained
using
an
organocatalyst.
This
method
provides
unprecedented
strategy
access
structurally
diverse
3,3'-disubstituted
bearing
a
sterically
congested
triaryl-containing
all-carbon
quaternary
stereocenter.
utility
this
approach
verified
formal
synthesis
cyclotryptamine
alkaloids.
Chemistry - A European Journal,
Год журнала:
2021,
Номер
28(2)
Опубликована: Окт. 29, 2021
The
application
of
dinuclear
zinc
catalysts
in
a
dearomatization
reaction
has
been
developed.
Catalytic
asymmetric
[3+2]
annulations
2-nitrobenzofurans
or
2-nitrobenzothiophenes
with
CF3
-containing
N-unprotected
isatin-derived
azomethine
ylides
catalyzed
by
are
realized
excellent
diastereomer
ratios
(dr)
>20
:
1
and
enantiomeric
excess
(ee)
up
to
99
%.
This
protocol
provides
practical,
straightforward
access
structurally
diverse
pyrrolidinyl
spirooxindoles
containing
2,3-fused-dihydrobenzofuran
(or
dihydrobenzothiphene)
moiety,
four
contiguous
stereocenters.
Reactions
can
be
performed
on
gram
scale.
absolute
configuration
products
is
confirmed
X-ray
single
crystal
structure
analysis,
possible
mechanism
proposed.
Asian Journal of Organic Chemistry,
Год журнала:
2021,
Номер
10(6), С. 1345 - 1376
Опубликована: Апрель 19, 2021
Abstract
Chiral
analogues
of
squaramides
have
been
fruitful
in
organocatalyzed
asymmetric
reactions
over
last
decade.
Alongside
other
H‐bonding
catalysts
like
ureas,
thioureas:
proved
to
be
efficient
for
the
formation
acyclic
and
cyclic
chiral
molecules.
A
wide
range
molecules
bearing
multiple
functionalities
stereocenters
synthesized
by
using
several
bifunctional
as
catalysts.
These
perform
base
utilizing
basic
N
atom
their
extension
help
stereoinduction
forming
H‐bonds
with
suitable
H‐bond
acceptors.
The
present
review
focuses
on
assembling
recent
progresses
synthesis
five
six
membered
rings
promoted
squaramides.
handful
articles
published
research
groups
documenting
construction
five‐
six‐membered
part
interesting
complex
molecular
architectures.
Different
methodologies
conventional
formal
cycloadditions
or
cascade
engineered
through
assistance
fabricate
carbo‐
heterocycles.
This
also
includes
dual
cooperative
catalytic
system
which
squaramide
is
one
Chemical Communications,
Год журнала:
2022,
Номер
58(21), С. 3493 - 3496
Опубликована: Янв. 1, 2022
An
efficient
and
concise
strategy
has
been
successfully
developed
for
merging
spiro-tetrahydroquinoline
with
spiro-benzofuranone
into
a
single
new
skeleton
through
asymmetric
catalytic
cascade
reactions
catalyzed
by
quinine-derived
chiral
bifunctional
squaramide
organocatalysts.
In
this
approach,
differently
substituted
derivatives
were
smoothly
obtained
high
yields,
excellent
diastereoselectivities
enantioselectivities
(up
to
99%
yield,
up
>20
:
1
dr,
>99%
ee,
40
examples)
under
mild
reaction
conditions.
