Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(36)
Опубликована: Июнь 5, 2024
Previous
N-glycosylation
approaches
have
predominately
involved
acidic
conditions,
facing
challenges
of
low
stereoselectivity
and
limited
scope.
Herein,
we
introduce
a
radical
activation
strategy
that
enables
versatile
stereoselective
using
readily
accessible
glycosyl
sulfinate
donors
under
basic
conditions
exhibits
exceptional
tolerance
towards
various
N-aglycones
containing
alkyl,
aryl,
heteroaryl
nucleobase
functionalities.
Preliminary
mechanistic
studies
indicate
pivotal
role
iodide,
which
orchestrates
the
formation
from
subsequent
generation
key
intermediate,
configurationally
well-defined
is
subsequently
attacked
by
an
N-aglycone
in
stereospecific
S
ACS Central Science,
Год журнала:
2024,
Номер
10(8), С. 1481 - 1489
Опубликована: Июль 12, 2024
Carbohydrates
regulate
an
inimitable
spectrum
of
biological
functions,
yet
successfully
leveraging
this
therapeutic
avenue
continues
to
be
frustrated
by
low
affinities
with
glycan-specific
proteins.
A
conspicuous
exception
is
the
interaction
monosialotetrahexosylganglioside
(GM1)
carbohydrate-recognition
domain
cholera
toxin
from
Abstract
Synthesis
of
the
tetrasaccharide
corresponding
to
O-antigen
Providencia
alcalifaciens
O7:H7
strain
was
achieved
in
satisfactory
yield
by
applying
a
stereoselective
glycosylation
strategy.
Stereoselective
incorporation
β-l-rhamnose,
α-d-glucosamine
and
α-d-glucose
moieties
very
good
yield.
The
d-glucuronic
acid
moiety
late-stage
TEMPO–bis(acetoxy)iodobenzene
(BAIB)-mediated
regioselective
oxidation
primary
hydroxyl
group
d-glucose
moiety.
Thioglycosides
were
used
as
glycosyl
donors
presence
combination
N-iodosuccinimide
(NIS)
triflic
(TfOH)
thiophilic
promoter.
We
herein
present
the
development
of
a
novel
glycosylation
protocol
using
glycosyl
o-N-(o-methoxybenzamidoyl)-propynyl
benzoates
as
donors,
activated
solely
by
catalytic
amount
In(OTf)3,
eliminating
need
for
Au(I)
catalyst.
This
approach
offers
mild
and
orthogonal
conditions,
enabling
across
broad
substrate
scope
facilitating
versatile
one-pot
strategies
glycan
assembly.
Mechanistic
insights
suggest
that
In(OTf)3
serves
dual
roles
being
recruited
to
auxiliary
group
through
σ-coordination
while
activating
alkyne
via
π-interaction.
Chemical Communications,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
Here,
we
disclose
the
discovery
that
isothioureas
efficiently
catalyze
formation
of
both
α-1,2-
cis
and
trans
glycosyl
linkages
from
either
bromide
or
chloride
donors,
furnishing
glycosides
in
good
to
complete
selectivities.
Beilstein Journal of Organic Chemistry,
Год журнала:
2025,
Номер
21, С. 369 - 406
Опубликована: Фев. 17, 2025
Stereoselective
glycosylations
are
one
of
the
most
challenging
tasks
synthetic
glycochemists.
The
protecting
building
blocks
on
glycosides
contribute
significantly
in
attaining
required
stereochemistry
resulting
glycosides.
Strategic
installation
suitable
groups
C-2
position,
vicinal
to
anomeric
carbon,
renders
neighbouring
group
participation,
whereas
distal
C-3,
C-4,
and
C-6
positions
often
claimed
exhibit
remote
participation
with
carbon.
Neighbouring
being
widely
studied
help
glycochemists
design
protocols
for
multistep
synthesis
complex
oligosaccharides
turn,
standardise
process
glycosylation
towards
a
particular
stereochemical
output.
While
has
been
quite
effective
achieving
produced
glycosides,
exhibits
comparatively
less
efficacy
complete
stereoselectivity
reactions.
Remote
is
still
highly
debated
topic
scientific
community.
However,
implementing
participating
role
reactions
practised
achieve
better
stereocontrol
facilitate
formation
synthetically
glycosidic
linkages.
Compounds,
Год журнала:
2025,
Номер
5(2), С. 8 - 8
Опубликована: Март 26, 2025
FOSs
are
short-chain
fructose-based
oligosaccharides
with
notable
functional
and
health
benefits.
Naturally
present
in
various
fruits
vegetables,
primarily
produced
enzymatically
or
microbially
from
sucrose
long-chain
fructans,
namely,
inulin.
Enzymes
such
as
fructosyltransferase,
β-fructofuranosidase,
endoinulinase
typically
involved
its
production.
The
chemical
structure
of
consists
an
assembly
fructose
residues
combined
a
glucose
unit.
increasing
consumer
demand
for
healthy
foods
has
driven
the
widespread
use
food
industry.
Thus,
have
been
incorporated
into
dairy
products,
beverages,
snacks,
pet
foods.
Beyond
feed
applications,
serve
low-calorie
sweetener
used
dietary
supplements
pharmaceuticals.
As
prebiotic,
they
enhance
gut
by
promoting
growth
beneficial
bacteria,
aid
digestion,
improve
mineral
absorption,
help
regulate
cholesterol
triglyceride
levels.
Generally
recognized
safe
(GRAS)
approved
global
regulatory
agencies,
valuable
ingredient
both
applications.
This
review
provides
updated
perspective
on
natural
sources
occurrence
FOSs,
their
structures,
physicochemical
physiological
features,
some
focus
critical
assessment
potential
Moreover,
FOS
production
methods
concisely
addressed,
forthcoming
developments
involving
suggested.
