Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(42), С. 29150 - 29158
Опубликована: Окт. 9, 2024
We
report
herein
the
first
asymmetric
photoinduced
excited-state
Nazarov
reaction
of
non-aromatic
dicyclic
divinyl
ketones
by
using
hydrogen-bonding
catalysis.
The
enantioselectivity
electrocyclization
is
highly
dependent
on
structural
features
substrate
and
its
interaction
with
chiral
catalysts.
For
simple
ketone
substrates,
there
no
discernible
selectivity
hydrogen
bond
coordination
between
thiourea
carbonyl
groups
substrates
in
ground
state.
However,
we
found
that
direction
was
well
controlled
each
model
Chemical Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
Bicyclo[3.2.0]heptane
lactones
represent
an
important
scaffold
in
bioactive
molecules.
Herein,
we
report
a
diastereoselective
synthetic
disconnection
to
access
bicyclo[3.2.0]heptane
from
bicyclo[1.1.1]pentane
carboxylic
acids,
which
proceeds
through
palladium-catalyzed
C-H
activation
and
C-C
cleavage
processes.
By
using
two
different
classes
of
ligands,
MPAA
pyridone-amine,
either
all-syn
arylated
or
non-arylated
ones
can
be
synthesized.
The
lactone
products
were
converted
into
multiple
substituted
cyclobutane,
γ-lactone,
oxobicyclo[3.2.0]heptane
derivatives
showcase
the
versatility
this
method.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(36)
Опубликована: Май 23, 2024
Bis(alkenyl)boronates
react
with
optically
active
Ir(π-allyl)
species
in
a
process
that
involves
allylation
of
the
more
substituted
olefin
and
1,2-metalate
shift
less
olefin.
The
method
constructs
valuable
enantioenriched
tertiary
allylic
boronic
esters
high
chemoselectivity,
enantioselectivity
diastereoselectivity.
Allylic
functionalization
reactions
transform
1,3-stereodiad
to
1,5-
1,6-stereochemical
relationships.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Июнь 26, 2024
Abstract
Cycloaddition
reactions
play
a
pivotal
role
in
synthetic
chemistry
for
the
direct
assembly
of
cyclic
architectures.
However,
hurdles
remain
extending
C4
synthon
to
construct
diverse
heterocycles
via
programmable
[4+n]-cycloaddition.
Here
we
report
an
atom-economic
and
modular
intermolecular
cycloaddition
using
furan-fused
cyclobutanones
(FCBs)
as
versatile
synthon.
In
contrast
well-documented
benzocyclobutenones,
this
is
complementary
version
FCB
reagent.
It
involves
C-C
bond
activation
sequence,
including
Rh-catalyzed
enantioselective
[4
+
2]-cycloaddition
with
imines
Au-catalyzed
diastereoselective
4]-cycloaddition
anthranils.
The
obtained
lactams,
which
are
motifs
that
present
many
natural
products,
bioactive
molecules,
materials,
inaccessible
or
difficult
prepare
by
other
methods.
Preliminary
antitumor
activity
study
indicates
6e
6
f
exhibit
high
anticancer
potency
against
colon
cancer
cells
(HCT-116,
IC
50
=
0.50
±
0.05
μM)
esophageal
squamous
cell
carcinoma
(KYSE-520,
0.89
0.13
μM),
respectively.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 12, 2024
Abstract
Enantioselective
synthesis
of
(spiro)cyclobutane
derivatives
poses
significant
challenges
yet
holds
promising
applications
for
both
synthetic
and
medicinal
chemistry.
We
report
here
a
nickel‐catalyzed
asymmetric
syn
‐hydrometalative
4‐
exo
‐
trig
cyclization
1,4‐alkynones
to
synthesize
alkenyl
cyclobutanols
with
tetrasubstituted
stereocenter.
This
strategy
features
broad
substrate
scope,
delivering
variety
trifluoromethyl‐containing
rigid
(spiro)carbocycle
skeletons
in
good
yields
high
enantioselectivities
(up
84
%
yield
98.5
:
1.5
er).
The
utility
is
demonstrated
through
stereospecific
transformations
into
fused
spiro
molecules.
Experimental
computational
mechanistic
studies
indicate
that
the
reaction
initiated
by
an
active
Ni−H
species,
carbonyl‐directed
hydrometalation
as
key
regioselective
control.
catalytic
method
provides
general
solution
hydrofunctionalization
alkynes
represents
efficient
pattern
assembling
highly
strained
enantioenriched
bioisosteres.
This
paper
describes
an
iridium-catalyzed
allylation
of
ring-fused
pyrazolones
that
proceeds
with
excellent
regio-,
diastereo-
and
enantio-selectivities.
The
approach
exploits
unactivated,
racemic
allylic
alcohols
as
a
source
allyl
building
blocks.
Asymmetric
syntheses
series
biologically
relevant,
chiral
highlight
the
utility
methodology.
use
Cu(OTf)
Research Square (Research Square),
Год журнала:
2024,
Номер
unknown
Опубликована: Фев. 6, 2024
Abstract
Cycloaddition
reactions
play
a
pivotal
role
in
synthetic
chemistry
for
the
direct
assembly
of
cyclic
architectures.
However,
substantial
hurdles
remain
extending
C4
synthon,
which
is
mainly
limited
to
dienes
and
1,4-dipoles
so
far,
construct
diverse
heterocycles
via
programmable
[4
+
n]-cycloaddition.
Here
we
report
an
atom-economic
modular
intermolecular
cycloaddition
using
furan-fused
cyclobutanones
(FCBs)
as
novel
versatile
synthon.
In
contrast
well-documented
intramolecular
benzocyclobutenones
(BCBs),
this
complementary
version
heteroarene-fused
reagent
building
block.
It
involves
catalytic
C-C
bond
activation
stepwise
annulation
sequence,
including
Rh-catalyzed
highly
enantioselective
2]-cycloaddition
with
imines
Au-catalyzed
diastereoselective
4]-cycloaddition
anthranils.
The
polycyclic
lactam
products
their
derivatives,
are
motifs
that
present
many
natural
products,
bioactive
molecules,
materials,
inaccessible
or
difficult
prepare
by
other
methods
multi-steps.
Preliminary
antitumor
activity
study
these
compounds
indicates
6e6f
exhibit
high
anticancer
potency
against
colon
cancer
cells
(HCT-116
cells,
IC50
=
0.50
±
0.05
µM)
esophageal
squamous
cell
carcinoma
(KYSE-520
0.89
0.13
µM),
respectively.
