Phosphine‐Catalyzed Divergent γ,γ‐ and ε,γ‐Umpolung Domino Additions of Bisoxindoles with Allenoates: Construction of Vicinal All‐Carbon Quaternary Stereocenters and Formal Total Synthesis of Dimeric Cyclotryptamine Alkaloids
Chinese Journal of Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 25, 2025
Comprehensive
Summary
Vicinal
all‐carbon
quaternary
stereocenters
are
widely
present
in
natural
products
and
bioactive
molecules.
However,
the
construction
of
such
motif
one
step
from
readily
available
starting
materials
remains
a
significant
challenge.
Herein,
we
report
phosphine‐catalyzed
divergent
γ,γ‐
ε,γ‐umpolung
domino
addition
bisoxindoles
with
allenoates.
This
method
serves
as
practical
tool
for
concise
synthesis
series
bisoxindole
derivatives
bearing
sterically
hindered
vicinal
under
mild
reaction
conditions.
The
applicability
this
novel
was
demonstrated
gram‐scale
three
known
advanced
intermediates
total
syntheses
calycanthine,
chimonanthine
folicanthine.
Язык: Английский
Phosphine-Catalyzed Cascade Cycloaddition of Vinyl Oxiranes with Sulfonium Compounds to Step-Economically Construct Spiro-2(3H)-furanone Scaffolds
Organic Letters,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 9, 2025
In
this
work,
we
developed
a
phosphine-catalyzed
cascade
lactonization/[2
+
1]
annulation
reaction
between
vinyl
oxiranes
and
sulfonium
compounds
for
the
highly
diastereoselective
construction
of
spiro-2(3H)-furanone
skeletons.
The
cycloaddition
proceeds
via
2(5H)-furanone
phosphonium
intermediate,
introducing
an
oxygen-containing
active
intermediate
phosphine
catalysis.
These
findings
highlight
significant
potential
harnessing
as
versatile
synthons
constructing
spirocyclic
through
simultaneous
multicyclic
skeleton
formation.
Язык: Английский
Recent advances in phosphine-mediated sequential annulations
Chinese Chemical Letters,
Год журнала:
2024,
Номер
unknown, С. 110628 - 110628
Опубликована: Ноя. 1, 2024
Язык: Английский
Cascade Alkynyl Prins Cyclization and Aza-Michael Reaction: En Route to Regioselective Pyrano- and Isochromenoquinoline Scaffolds
The Journal of Organic Chemistry,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 20, 2024
A
metal-free,
Lewis
acid
approach
for
the
regioselective
synthesis
of
dihydropyranoquinoline
scaffolds
has
been
unveiled.
The
methodology
employs
a
cascade
alkynyl
Prins-aza-Michael
reaction
sequence
to
deliver
products
in
good
excellent
yields.
strategy
features
mild
conditions,
broad
substrate
scope,
and
high
functional
group
tolerance.
protocol
further
extended
include
isochromenoquinoline
derivatives.
utility
lies
highly
fused
polycyclic
N,O-heterocycles
via
intramolecular
Heck
coupling.
Additionally,
Rh(III)-catalyzed
annulation
results
formation
fluorescent
pentacyclic
ammonium
salts
Photophysical
studies
reveal
that
these
exhibit
strong
emission
green
region
(500-550
nm).
Язык: Английский
DMAP-Catalyzed [4 + 2] Annulation of Hex-5-en-2-ynoates with Electron-Poor Alkenes
Organic Letters,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 20, 2024
Herein,
we
report
a
DMAP-catalyzed
[4
+
2]
annulation
reaction
of
hex-5-en-2-ynoates
1
with
electron-poor
alkenes
2,
which
affords
exocyclic
olefinic
cyclohexenes
3
in
good
yields
and
excellent
regio-,
diastereo-,
E/Z
selectivities.
Distinguished
from
previous
allenoate-
or
alkynoate-based
substrates,
use
the
β-
ε-carbons
for
bond
formation,
presenting
new
regiodivergent
C4
synthons
Lewis
base-catalyzed
annulations.
Язык: Английский