Synthesis,
Год журнала:
2023,
Номер
56(07), С. 1183 - 1199
Опубликована: Окт. 17, 2023
Abstract
The
glycosylation
reaction
is
one
of
the
important
aspects
carbohydrate
chemistry,
where
two
different
units
are
frequently
linked
through
C–O
bonds.
In
pursuit
advancing
this
field,
design
and
development
sustainable
catalytic
methods
for
O-glycosylation,
which
can
provide
an
alternate
effective
tool
to
traditional
protocols
involving
stoichiometric
promoters
classical
donors,
considered
as
highly
challenging,
yet
facets
glycochemistry.
Herein,
we
report
a
simple
efficient
Fe(III)-catalyzed
method
O-glycosylation
activation
bifunctional
phenylpropiolate
glycoside
(PPG)
donors.
This
mild
involves
use
inexpensive
less
toxic
FeCl3
catalyst
easily
synthesizable,
benchtop-stable
glycosyl
ester-based
PPG
react
with
various
sugar
well
non-sugar-based
acceptors
deliver
corresponding
O-glycosides
in
good
yields
moderate
anomeric
selectivity,
along
regeneration
separable
phenylpropiolic
acid.
Importantly,
d-mannose
l-rhamnose-based
donors
afforded
high
α-anomeric
selectivity.
conditions
were
further
explored
synthesis
trisaccharides.
Organic Letters,
Год журнала:
2024,
Номер
26(25), С. 5396 - 5401
Опубликована: Июнь 13, 2024
A
stereodivergent
synthesis
of
β-
and
α-O-glycosides
using
3-O-quinaldoyl
glucals
was
developed
by
palladium
catalysis
at
60
110
°C
respectively.
Various
alcohols,
monosaccharides,
amino
acid
were
glycosylated
to
form
α-
products
in
good
yields
with
high
stereoselectivity.
Mechanistic
studies
indicated
no
classic
Pd–N
(quinoline)
coordination,
but
π–π
stacking
interactions
promoted
the
anomeric
stereodiversity.
The
practicality
demonstrated
glycosylating
natural
products/drugs
synthesizing
a
complex
tetrasaccharide.
Advanced Synthesis & Catalysis,
Год журнала:
2023,
Номер
365(14), С. 2350 - 2355
Опубликована: Июнь 28, 2023
Abstract
A
one‐pot
synthesis
of
2,3,4‐unprotected
β‐
N
‐glycopyranosides
from
glycals
and
amines
with
exclusive
β‐stereoselectivity
under
room
temperature
conditions
is
reported.
This
method
was
achieved
via
palladium‐catalyzed
Tsuji‐Trost
amination
followed
by
dihydroxylation
directly,
tolerating
anilines,
heterocyclic
aromatic
amines,
,
O
‐dimethylhydroxylamine,
especially
the
reaction
primary
has
not
been
reported
before.
Furthermore,
protocol
applied
to
modify
clinical
drugs
(prazosin,
imiquimod)
construct
analogue
natural
product
amphimedoside
A.
Abstract
A
noncovalent
organocatalytic
concerted
addition
of
phenol
to
glycal
is
developed
for
the
stereoselective
and
regioselective
construction
biologically
important
phenolic
2‐deoxyglycosides,
featuring
wide
substrate
tolerance.
The
method
relies
on
an
anion‐bridged
dual
hydrogen
bond
interaction
which
experimentally
proved
by
Nuclear
Magnetic
Resonance
(NMR),
Ultraviolet
visible
(UV–vis),
fluorescence
analysis.
Experimental
evidence
including
kinetic
analysis,
Kinetic
Isotope
Effect
(KIE)
studies,
linear
free
energy
relationship,
Hammett
plot,
density
functional
theory
(DFT)
calculations
provided
a
mechanism
where
high‐energy
oxocarbenium
ion
not
formed.
In
addition,
potential
utility
this
further
demonstrated
synthesis
active
glycosylated
flavones.
benchmarking
studies
demonstrate
significant
advances
in
newly
compared
previous
approaches.
ACS Omega,
Год журнала:
2024,
Номер
9(10), С. 11969 - 11975
Опубликована: Март 4, 2024
Compared
with
stereoselective
glycosylation
methods
mainly
addressed
on
the
preparation
of
pyranose
glycosides,
furanosylation
has
been
more
limited,
especially
for
1,2-cis
arabinofuranosylation.
Herein,
we
report
a
novel
1,2-cis-arabinofuranosylation
strategy
using
conformationally
restricted
3,5-O-xylylene-protected
arabinofuranosyl
donor
activation
B(C6F5)3
desired
targets
in
moderate
to
excellent
yields
and
β-stereoselectivity.
The
effectiveness
was
demonstrated
successfully
various
acceptors,
including
carbohydrate
alcohols.
The Journal of Organic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 18, 2025
We
present
a
new
strategy
for
the
synthesis
of
O-aryl
glycosides
through
formal
insertion
glycosylidene
carbenes
into
O–H
bond
phenols.
The
key
carbene
intermediates
were
generated
in
situ
by
copper-catalyzed
oxidation
bench-stable
diaziridine
precursors.
This
method
enables
glycosylation
variety
phenols
with
good
yields,
excellent
diastereoselectivity,
and
chemoselectivity,
providing
highly
practical
late-stage
complex
natural
products
bioactive
agents.
The
significance
of
2-deoxy
glycosides
in
biologically
active
compounds
is
well-established,
as
they
frequently
play
a
pivotal
role
modulating
the
efficacy
therapeutic
agents.
sugar
embodies
distinctive
class
carbohydrates
characterized
by
marked
differences
stability,
reactivity,
and
selectivity
compared
to
their
counterparts
bearing
C2-oxygen
or
other
heteroatoms.
As
result,
stereoselective
synthesis
this
carbohydrate
complicated
its
sensitivity
acidic
conditions
propensity
for
hydrolysis
elimination
reactions.
Furthermore,
lack
functionality
presents
an
additional
challenge
controlling
stereoselectivity.
In
study,
we
report
application
commercially
available
phenanthroline
effective
additive
glycosylation
aliphatic
alcohols
phenolic
nucleophiles
with
glycosyl
chlorides,
facilitating
efficient
access
variety
α-2-deoxy
high
yields
synthetically
useful
Kinetic
analyses
suggest
that
plays
crucial
reaction.
Advanced Synthesis & Catalysis,
Год журнала:
2023,
Номер
365(17), С. 2949 - 2958
Опубликована: Июль 27, 2023
Abstract
L‐Prolinethioamide
catalyzes
direct
stereoselective
glycosylation
of
glycal
donors
to
access
2‐deoxyglycosides
under
moderate
reaction
conditions.
This
proposed
protocol
produced
the
desired
products
in
up
88%
yield
and
shows
greater
tolerance
glycosyl
acceptors
a
broad
substrate
scope
with
better
stereoselectivity.
method
is
also
applicable
for
less
nucleophilic
such
as
phenol.
In
addition,
1,1′‐linked
trehalose‐type
analogues
can
be
accessed
through
this
methodology.
Further,
mechanistic
studies
suggest
that,
glycosylation,
L‐prolinethioamide
operates
via
Brønsted
acid/base
catalysis.
Advanced Synthesis & Catalysis,
Год журнала:
2023,
Номер
365(10), С. 1699 - 1704
Опубликована: Май 5, 2023
Abstract
S
‐Glycosides
are
considerably
more
stable
toward
chemical
degradation
and
enzymatic
hydrolysis
than
O
‐glycosides,
thioglyco‐peptides/proteins
also
demonstrate
critical
bioactivities
in
the
living
system.
However,
general
stereoselective
synthetic
strategies
still
challenging.
Herein,
a
versatile
‐glycosylation
approach
was
developed
by
palladium‐catalyzed
allylic
substitution
to
form
α‐
β‐thioglycosides
respectively
under
mild
conditions.
A
wide
range
of
substrates
were
tolerated
afford
thioglycosides
stereospecific
manner
with
70%–86%
yields.
This
protocol
created
quick
access
various
‐linked
disaccharides
glycopeptides.
magnified
image
