Two
different
cascade
pathways
to
access
spirobutenolides
were
achieved
based
on
the
substrate-controlled
regioselectivity
of
deconjugated
butenolides.
A
new
class
functional
butenolides
was
designed
and
exhibited
superior
γ-regioselectivity
in
vinylogous
Michael/Michael
reactions
with
cinnamaldehydes.
The
aryl-substituted
cinnamaldehydes
underwent
a
Michael/Michael/aldol/dehydration
process
induced
by
double
α-regioselectivities.
Both
conjugated
could
be
obtained
good
yields
excellent
enantioselectivities.
Journal of Agricultural and Food Chemistry,
Год журнала:
2022,
Номер
70(35), С. 10693 - 10707
Опубликована: Авг. 23, 2022
Spiro
compounds
are
biologically
active
organic
with
unique
structures,
found
in
a
wide
variety
of
natural
products
and
drugs.
They
do
not
readily
lead
to
drug
resistance
due
their
mechanisms
action
have,
therefore,
attracted
considerable
attention
regarding
pesticide
development.
Analyzing
structure-activity
relationships
(SARs)
summarizing
the
characteristics
spiro
high
activity
crucial
steps
design
development
new
pesticides.
This
review
mainly
summarizes
insecticidal,
bactericidal,
fungicidal,
herbicidal,
antiviral,
plant
growth
regulating
functions
provide
insight
for
creation
compound
Angewandte Chemie International Edition,
Год журнала:
2021,
Номер
60(26), С. 14545 - 14553
Опубликована: Апрель 14, 2021
The
collective
synthesis
of
skeletally
diverse
Stemona
alkaloids
featuring
tailored
dyotropic
rearrangements
β-lactones
as
key
elements
is
described.
Specifically,
three
typical
5/7/5
tricyclic
skeletons
associated
with
stemoamide,
tuberostemospiroline
and
parvistemonine
were
first
accessed
through
chemoselective
involving
alkyl,
hydrogen,
aryl
migration,
respectively.
By
the
rational
manipulation
substrate
structures
reaction
conditions,
these
proceeded
excellent
efficiency,
good
chemoselectivity
high
stereospecificity.
Furthermore,
several
polycyclic
alkaloids,
including
saxorumamide,
isosaxorumamide,
stemonine
bisdehydroneostemoninine,
obtained
from
aforementioned
late-stage
derivatizations.
A
novel
visible-light
photoredox-catalyzed
formal
[3+2]
cycloaddition
was
also
developed,
which
offers
a
valuable
tool
for
accessing
oxaspirobutenolide
related
scaffolds.
Organic Letters,
Год журнала:
2023,
Номер
25(5), С. 810 - 815
Опубликована: Янв. 27, 2023
A
visible-light-mediated
difunctionalization
of
activated
alkynes
with
boronic
acid
is
unveiled
to
synthesize
3-alkylated
coumarins
and
unsaturated
spiro-lactones.
The
substituent
at
the
para-position
aryl
ring
alkynoate
plays
a
pivotal
role
in
selective
formation
chain-alkylated
or
spirocyclic
compounds
under
mild
conditions.
reaction
employs
hypervalent
iodine
reagent
ruthenium
photocatalyst.
spiro-lactones
thus
obtained
were
subjected
another
novel
mode
radical
addition
cascade
cyclization
(RACC)
access
various
new
fused
compounds.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
89(11), С. 7366 - 7375
Опубликована: Янв. 5, 2023
3-Diazotetramic
acids
were
found
to
be
valid
substrates
for
the
recently
discovered
approach
toward
natural-like
Δα,β-spirobutenolides
via
Rh(II)-catalyzed
O–H
insertion
into
propiolic
followed
by
base-promoted
intramolecular
Michael
addition.
The
target
obtained
in
generally
high
yields
and,
case
of
chiral
5-monosubstituted
3-diazotetramic
acids,
diastereoselectivity.
synthesis
that
we
report
here
was
virtually
insensitive
structure
though
it
somewhat
sensitive
thereby
demonstrating
quite
a
large
scope.
Thus,
new
class
α-diazocarbonyl
compounds
suitable
realization
outlined
above
identified.
Chemistry - A European Journal,
Год журнала:
2021,
Номер
27(31), С. 8221 - 8227
Опубликована: Апрель 14, 2021
Abstract
α‐Diazo
homophotalimides
were
reacted
with
various
propiolic
acids
on
Rh
2
(esp)
catalysis.
The
resulting
propiolate
esters
transformed
into
novel,
heterocyclic
Δ
α,β
‐spirobutenolides
in
good
to
excellent
product
yields.
approach
represents
a
fundamentally
novel
entry
natural‐like
present
many
biologically
active
natural
products
as
well
fully
synthetic
compounds
endowed
diverse
biological
activities.
thus
obtained
shown
inhibit
thioredoxin
reductase,
selenocysteine
enzyme
target
for
cancer.
Moreover,
the
best
compound
series
(TrxR
IC
50
1.49±0.08
μM),
by
using
MALDI‐TOF
mass‐spectrometry
it
was
that
selectively
binds
presence
of
10‐fold
excess
cysteine.
This
validates
new
promising
lead
anticancer
therapy
development.
Polyhedron,
Год журнала:
2022,
Номер
219, С. 115790 - 115790
Опубликована: Март 23, 2022
Magnesium
(Mg)
constitutes
one
of
the
most
abundant
metal
elements
in
Earth’s
crust.
The
spectacular
career
magnesium
organic
chemistry
has
been
initiated
at
beginning
XX
century
and
still
lasting
today.
discovery
organomagnesium
compounds
by
Philippe
A.
Barbier
Victor
Grignard
is
commonly
recognized
as
milestones
development
(organic)
chemistry.
subsequent
applications
reagents
relatively
easy
generated
synthons
enantioselective
reactions
have
opened
new
possibilities
for
acquiring
enantiomerically
enriched
compounds.
On
other
hand,
asymmetric
which
plays
a
role
catalyst
can
be
considered
limited,
especially
when
their
number
compared
to
contributions
aimed
transition
metal-catalyzed
or
organocatalyzed
stereoselective
transformations.
However,
taking
into
account
current
trends
replacing
expensive
metals
with
cheaper
counterparts
making
catalysis
more
environmentally
(and
user)
friendly,
modification
known
methods,
employ
Earth-abundant
metals,
very
advisable.
In
this
study
we
intend
emphasize
chemistry,
mainly
catalytic
synthesis.
Among
already
reported
procedures,
discussed
recent
examples,
however,
also
mentioned
some,
groundbreaking
previous
ones.
An
exception
pericyclic
made,
these
constitute
first
examples
use
attention
drawn
some
structural
aspects,
associated
either
experimentally-determined
geometry
species
calculated
state(s)
given
transformation.
Organic Letters,
Год журнала:
2021,
Номер
23(15), С. 5698 - 5702
Опубликована: Июль 15, 2021
A
novel
and
effective
method
for
the
synthesis
of
spirolactones
from
readily
available
α-keto
acids
1,3-enynes
is
developed
via
a
BF3·Et2O-promoted
cascade
annulation.
This
sequential
process
conducted
at
room
temperature,
it
provides
functionalized
in
good
to
excellent
yield
under
metal-free
conditions.
The Journal of Organic Chemistry,
Год журнала:
2023,
Номер
88(11), С. 6890 - 6900
Опубликована: Май 11, 2023
The
stereoselective
synthesis
of
spirocyclic
pyrazolin-5-ones
by
N-heterocyclic
carbene
(NHC)
organocatalysis
has
been
less
studied
so
far.
For
this
reason
and
considering
the
interest
class
compounds,
here,
we
present
NHC-catalyzed
[3
+
2]-asymmetric
annulation
β-bromoenals
1H-pyrazol-4,5-diones
that
achieves
to
produce
chiral
spiropyrazolone-butenolides.
is
general
for
aryl
heteroaryl
β-bromo-α,β-unsaturated
aldehydes
1,3-disubstituted
pyrazolones.
spirobutenolides
have
obtained
in
good
yields
(up
88%)
enantioselectivities
97:3
er).
This
constitutes
first
described
example
using
pyrazoldiones
as
starting
materials
spiro
compounds.
Organic Chemistry Frontiers,
Год журнала:
2022,
Номер
9(11), С. 2921 - 2925
Опубликована: Янв. 1, 2022
A
green
and
sustainable
electrochemical
oxidative
dearomatization
of
2-arylthiophenes
has
been
developed
toward
the
preparation
both
C2/C3
C2/C5
difunctionalized
thiophenones.