The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
unknown
Опубликована: Ноя. 12, 2024
α-Methoxytropone
is
a
structural
motif
found
in
various
natural
products
and
other
compounds
of
interest
to
the
scientific
community
but
remains
synthetic
challenge.
The
present
Note
describes
synthesis
variously
substituted
α-methoxytropones
related
through
an
intermolecular
3-hydroxy-4-pyrone-based
oxidopyrylium
(5
+
2)
cycloaddition
followed
by
samarium
iodide-mediated
reductive
ring-opening.
strategy
highlighted
novel
AC-ring
analogue
colchicine
compare
it
existing
methods.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Май 15, 2024
Abstract
Skeletal
modifications
enable
elegant
and
rapid
access
to
various
derivatives
of
a
compound
that
would
otherwise
be
difficult
prepare.
They
are
therefore
powerful
tool,
especially
in
the
synthesis
natural
products
or
drug
discovery,
explore
different
improve
properties
candidate
starting
from
common
intermediate.
Inspired
by
biosynthesis
cephalotane
products,
we
report
here
single-atom
insertion
into
framework
benzenoid
subfamily,
providing
troponoid
congeners
—
representing
reverse
proposed
(i.e.,
contra-biosynthesis
approach).
Computational
evaluation
our
designed
transformation
prompted
us
investigate
Büchner–Curtius–Schlotterbeck
reaction
p
-quinol
methylether,
which
ultimately
results
harringtonolide
two
steps
cephanolide
A,
had
previously
prepared.
Additional
computational
studies
reveal
unconventional
selectivity
outcomes
driven
choice
Lewis
acid
nucleophile,
should
inform
further
developments
these
types
reactions.
ACS Catalysis,
Год журнала:
2025,
Номер
unknown, С. 3184 - 3190
Опубликована: Фев. 6, 2025
A
direct
electroreductive
functionalization
of
tropones
employing
aldehydes
as
alkylating
agents
is
reported.
This
C(sp2)-H
process
leverages
the
mediation
electroactive
nickel
complexes,
enabling
a
wide
range
both
native
and
substituted
(44
examples)
to
be
alkylated
selectively
at
α-position
in
high
yields
(up
90%).
Combined
electrochemical,
spectroelectrochemical,
computational
analyses
disclosed
whole
mechanistic
pathway
revealed
key
role
played
by
reduced
Ni
complexes
activating
tropone
core
toward
condensation
with
aldehydes.
The
fascinating
benzenoid
and
troponoid
Cephalotaxus
diterpenoids
are
highly
related
biosynthetically,
both
of
which
popular
targets
for
total
synthesis.
Herein,
we
describe
a
unified
strategy
the
concise
synthesis
cephanolide
A
harringtonolide
in
14
16
steps
respectively.
Palladium
catalyzed
Csp2-Csp3
cross-coupling
followed
by
doubly
electron-deficient
intramolecular
Diels-Alder
reaction
secure
rapid
construction
carbon
framework.
Late-stage
benzenoid-to-troponoid
ring
expansion
was
accomplished
employing
Büchner-Curtius-Schlotterbeck
(BCS)
reaction,
furnishing
two
from
A.
This
work
shed
light
on
chemical
synthetic
connection
between
diterpenoids.
Inspired
by
the
biosynthesis
of
cephalotane
natural
products,
we
envisioned
that
a
“single-atom
insertion”
into
framework
benzenoid
subfamily
would
provide
access
to
troponoid
congeners
—
representing
reverse
proposed
(i.e.,
“contra-biosynthesis”
approach).
Computational
evaluation
our
designed
transformation
prompted
us
investigate
Büchner–Curtius–Schlotterbeck
reaction
p-quinol
methylether,
which
ultimately
resulted
in
synthesis
harringtonolide
two
steps
from
cephanolide
A,
had
previously
prepared.
Additional
computational
studies
revealed
unconventional
selectivity
outcomes
were
driven
choice
Lewis
acid
and
nucleophile,
should
inform
further
developments
these
types
reactions.
Reviews in Inorganic Chemistry,
Год журнала:
2024,
Номер
44(3), С. 323 - 337
Опубликована: Фев. 16, 2024
Abstract
In
the
last
few
decades,
photochemistry
has
great
influence
on
all
type
of
synthetic
processes.
While
photochemical
synthesis
is
emerging
field
in
inorganic
chemistry
as
it
impart
various
magnificent
properties
to
materials
that
are
used
for
nano-sized
giant
supramolecular
structures.
There
many
based
approaches
like
electron,
atom,
energy
transfer
depending
upon
need
product
where
one
can
switch
pathway.
A
variety
compounds
have
been
synthesized
dienes,
nitrides,
indoles,
gold
nano-particles
and
structures
using
route.
Photochemical
applications
artificial
photosynthesis
fluorophores.
Advanced Synthesis & Catalysis,
Год журнала:
2024,
Номер
366(9), С. 1965 - 1971
Опубликована: Март 5, 2024
Abstract
The
first
site‐selective
electrochemical
alkylation
of
tropones
is
realized
by
reacting
2‐acetoxytropones
and
redox‐active‐esters
(RAEs).
electroreductive
protocol
enables
the
preparation
mono‐
disubstituted
in
high
yields
(up
to
71%)
under
very
mild
conditions.
Dedicated
voltammetric
measurements
served
for
identification
as
a
class
valuable
trapping
agents
nucleophilic
radical
species
shed
light
on
whole
mechanistic
profile.
Wide
tolerance
towards
functional
groups
(27
examples)
application
late‐stage
functionalization
bioactive
compound
(
i.
e
.
Colchicine
analogue),
emphasize
synthetic
impact
present
methodology.
Abstract
A
bromotropone
corresponding
to
the
agylcone
of
glycosylated
sesquiterpenoid
natural
product
liriosmaside
has
been
prepared
over
ten
steps
and
in
a
fully
regio‐controlled
manner
through
gem
‐dibromocyclopropane‐mediated
ring‐expansion
readily
accessible
decalenone.
Pd[0]‐mediated
glucosylation
reaction
applied
this
afforded
mixture
from
which
an
enantiomerically
pure
cross‐coupling
could
be
obtained
its
structure
confirmed
single‐crystal
X‐ray
analysis
derivative.
Various
(unsuccessful)
attempts
are
described
selectively
acylate
last
compound
thereby
install
3‐hydroxy‐3‐methylglutaric
acid
or
HMGA‐containing
side
chain
title
product.
literature
survey
other
products
embodying
HMGA
motif
suggest
that
co‐metabolite
B
S
‐configured
at
C3”.
The
evaluation
glucosylated
tropone
series
anti‐bacterial,
anti‐fungal
cytotoxicity
assays
reveals
it
is
inactive
all
these
so
emphasizing
prospect
related
troponoids,
including
B,
can
serve
as
useful
models
for
new
anti‐viral
agents.
Chemical Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
An
efficient
visible-light-driven
method
for
achieving
α-site-selective
C–H
alkylation
of
tropones
was
developed.
It
applied
to
transform
fortunolide
A
into
cephafortunoids
and
B,
marking
the
first
synthesis
C
20
Cephalotaxus
troponoids.
European Journal of Organic Chemistry,
Год журнала:
2023,
Номер
27(6)
Опубликована: Дек. 27, 2023
Abstract
Reactions
of
dimethyl
2‐arylcyclopropane‐1,1‐dicarboxylates,
used
as
representatives
D‐A
cyclopropanes,
with
tropothione
were
carried
out
in
the
presence
scandium
triflate
a
catalyst,
under
mild
conditions
(CH
2
Cl
solution,
rt).
The
anticipated
(8+3)‐cycloaddition
products,
cycloheptatriene
fused
thiopyrans,
obtained
good
to
excellent
yields.
Cycloadditions
occurred
complete
diastereoselectivity
and
all
cases
single
diastereomers
formed.
Structures
isolated
cycloadducts
established
based
on
spectroscopic
data
two
they
unambiguously
confirmed
by
crystal
X‐ray
diffraction
analysis.
In
contrast
an
analogous
reported
for
parent
tropone,
which
was
performed
Ni(ClO
4
)
,
no
1,3‐
H
shift
leading
products
possessing
CH
moiety
located
within
seven‐membered
ring
observed.
