Cu(II)-NHC Catalyzed Insertion of Quinoid Carbenes into cis-Epoxides: Stereoselective Synthesis of trans-Dihydronaphthodioxine
Organic Letters,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 28, 2025
A
straightforward
synthesis
of
trans-dihydronaphthodioxine
has
been
efficiently
accomplished
through
Cu(II)-NHC
catalysis,
involving
the
stereoselective
ring
opening
cis-epoxides
with
quinoid-carbene.
Intramolecular
SN2-like
substitution
facilitates
inversion
stereochemistry
during
cis-epoxide
opening.
This
reaction
developed
under
simple
conditions,
demonstrating
a
broad
substrate
scope
wide
chemoselective
profile.
Additionally,
late-stage
functionalization
complex
bioactive
molecules
successfully
achieved.
Язык: Английский
Elucidating reactive sugar-intermediates by mass spectrometry
Communications Chemistry,
Год журнала:
2025,
Номер
8(1)
Опубликована: Март 7, 2025
The
stereoselective
introduction
of
glycosidic
bonds
is
one
the
greatest
challenges
in
carbohydrate
chemistry.
A
key
aspect
controlling
glycan
synthesis
glycosylation
reaction
which
linkages
are
formed.
outcome
governed
by
a
reactive
sugar
intermediate
-
glycosyl
cation.
Glycosyl
cations
highly
unstable
and
short-lived,
making
them
difficult
to
study
using
established
analytical
tools.
However,
mass-spectrometry-based
techniques
perfectly
suited
unravel
structure
gas
phase.
main
approach
involves
isolating
intermediate,
free
from
external
influences
such
as
solvents
promoters.
Isolation
allows
examining
their
integrating
orthogonal
spectrometric
spectroscopic
technologies.
In
this
perspective,
recent
achievements
gas-phase
research
on
highlighted.
It
provides
an
overview
used
probe
methods
for
interpreting
spectra.
connections
between
data
mechanisms
solution
explored,
given
that
reactions
typically
performed
solution.
Язык: Английский
Formally Stereoretentive SN1 Reactions of Homoallylic Tertiary Alcohols Via Nonclassical Carbocation
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 27, 2025
We
present
a
stereoretentive
nucleophilic
substitution
of
homoallylic
tertiary
alcohols
via
the
formation
nonclassical
cyclopropyl
carbinyl
(CPC)
carbocation
intermediate.
This
strategy
enables
creation
highly
congested
centers
with
preserved
stereocontrol,
addressing
typical
challenges
instability
and
reactivity
in
SN1
mechanisms.
The
stabilization
CPC
intermediate
is
crucial
for
achieving
precise
regio-
stereoselectivity,
significantly
enhancing
utility
SN1-type
mechanisms
complex
molecule
synthesis.
Язык: Английский