We
report
here
a
new
catalytic
and
exclusively
cis-selective
glycosylation
strategy
for
multigram
scale
synthesis
of
biologically
valuable
Tn
antigens.
The
underlying
iron-catalyzed
glycal
1,2-cis-aminoglycosylation
method
is
effective
with
variety
galactosyl
donors
amino
acid
acceptors
consistently
high
stereoselectivity.
Rapid
scalable
postglycosylation
transformations
readily
afford
single
diastereomeric
antigens
in
yields.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(38)
Опубликована: Июнь 7, 2023
Glycosyl
radical
functionalization
is
one
of
the
central
topics
in
synthetic
carbohydrate
chemistry.
Recent
advances
metal-catalyzed
cross-coupling
chemistry
and
metallaphotoredox
catalysis
provided
powerful
platforms
for
glycosyl
diversification.
In
particular,
discovery
new
precursors
conjunction
with
these
advanced
reaction
technologies
have
significantly
expanded
space
compound
synthesis.
this
Review,
we
highlight
most
recent
progress
area
starting
from
2021,
reports
included
will
be
categorized
based
on
different
types
better
clarity.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(18)
Опубликована: Март 7, 2023
Stereoselective
C-glycosylation
reactions
are
increasingly
gaining
attention
in
carbohydrate
chemistry
because
they
enable
glycosyl
precursors,
readily
accessible
as
anomeric
mixtures,
to
converge
a
single
diastereomeric
product.
However,
controlling
the
stereochemical
outcome
through
transition-metal
catalysis
remains
challenging,
and
methods
that
leverage
bench-stable
heteroaryl
sulfone
donors
facilitate
glycosylation
rare.
Herein,
we
show
two
complementary
nonprecious
metal
catalytic
systems,
based
on
iron
or
nickel,
which
capable
of
promoting
efficient
C-C
coupling
between
sulfones
aromatic
nucleophiles
electrophiles
distinct
mechanisms
modes
activation.
Diverse
C-aryl
glycosides
were
secured
with
excellent
selectivity,
scope,
functional-group
compatibility,
reliable
access
both
α
β
isomers
was
possible
for
key
sugar
residues.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Март 30, 2024
Abstract
C-oligosaccharides
are
found
in
natural
products
and
drug
molecules.
Despite
the
considerable
progress
made
during
last
decades,
modular
stereoselective
synthesis
of
continues
to
be
challenging
underdeveloped
compared
technology
O-oligosaccharides.
Herein,
we
design
a
distinct
strategy
for
efficient
via
palladium-catalyzed
nondirected
C1–H
glycosylation/C2-alkenylation,
cyanation,
alkynylation
2-iodoglycals
with
glycosyl
chloride
donors
while
realizing
difunctionalization
2-iodoglycals.
The
catalysis
approach
tolerates
various
functional
groups,
including
derivatives
marketed
drugs
products.
Notably,
obtained
can
further
transformed
into
C-glycosides
fully
conserving
stereochemistry.
results
density
theory
(DFT)
calculations
support
oxidative
addition
mechanism
alkenyl-norbornyl-palladacycle
(ANP)
intermediate
α-mannofuranose
high
stereoselectivity
glycosylation
is
due
steric
hindrance.
Organic Letters,
Год журнала:
2025,
Номер
27(4), С. 954 - 960
Опубликована: Янв. 21, 2025
A
novel
strategy
is
reported
for
the
stereoselective
synthesis
of
C(sp2)-C(sp3)
C-glycosides,
which
converts
heteroaryl
S-glycosides
into
C-glycosides
with
retention
configuration
through
a
sequential
process
involving
oxidation
and
Grignard
reagent
attack.
The
new
method
involves
generation
S(IV)
intermediate,
followed
by
ligand
coupling
glycosyl
groups
to
yield
C-glycosides.
diverse
were
achieved
good
efficiency.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(24), С. 16753 - 16763
Опубликована: Июнь 11, 2024
In
the
realm
of
organic
synthesis,
catalytic
and
stereoselective
formation
C-glycosidic
bonds
is
a
pivotal
process,
bridging
carbohydrates
with
aglycones.
However,
inherent
chirality
saccharide
scaffold
often
has
substantial
impact
on
stereoinduction
imposed
by
chiral
ligand.
this
study,
we
have
established
an
unprecedented
zirconaaziridine-mediated
asymmetric
nickel
catalysis,
enabling
diastereoselective
coupling
bench-stable
glycosyl
phosphates
range
(hetero)aromatic
glycal
iodides
as
feasible
electrophiles.
Our
developed
method
showcases
broad
scope
high
tolerance
for
various
functional
groups.
More
importantly,
precise
stereocontrol
toward
both
anomeric
configurations
forming
C(sp2)-glycosides
can
be
realized
simply
utilizing
popular
bioxazoline
(biOx)
ligands
in
reductive
Ni
catalysis.
Regarding
operating
mechanism,
experimental
computational
studies
support
occurrence
redox
transmetalation
leading
to
transient,
bimetallic
Ni–Zr
species
that
acts
potent
efficient
single-electron
reductant
process.
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Июнь 19, 2024
Abstract
C-
1
Glycals
serve
as
pivotal
intermediates
in
synthesizing
diverse
C
-glycosyl
compounds
and
natural
products,
necessitating
the
development
of
concise,
efficient
user-friendly
methods
to
obtain
glycosides
is
essential.
The
Suzuki-Miyaura
cross-coupling
glycal
boronates
notable
for
its
reliability
non-toxic
nature,
but
donor
stability
remains
a
challenge.
Herein,
we
achieve
significant
breakthrough
by
developing
stable
boronates,
effectively
overcoming
issue
glycal-based
Suzuki–Miyaura
coupling.
Leveraging
balanced
reactivity
our
establish
robust
palladium-catalyzed
reaction,
facilitating
formation
various
C(
sp
2
)-C(
),
3
)
bonds
under
mild
conditions.
Notably,
expand
upon
this
achievement
DNA-compatible
reaction
synthesize
glycal-DNA
conjugates.
With
excellent
reactivity,
stability,
generality,
ease
handling,
method
holds
promise
widespread
appication
preparation
products.
Organic Letters,
Год журнала:
2023,
Номер
25(36), С. 6741 - 6745
Опубликована: Авг. 30, 2023
The
synthesis
of
neopetrosins
A
and
C,
two
2-indolyl
C-α-d-mannopyranosides,
their
congeners
has
been
realized
via
a
direct
Ni/photoredox-catalyzed
reductive
coupling
3-methoxycarbonyl-2-iodo-1H-indoles
with
pyranosyl
bromides.
ACS Catalysis,
Год журнала:
2024,
Номер
14(15), С. 11532 - 11544
Опубликована: Июль 19, 2024
Glycosyl
donor
activation
emerged
as
an
enabling
technology
for
anomeric
functionalization,
but
aimed
primarily
at
O-glycosylation.
In
contrast,
we
herein
disclose
mechanistically
distinct
electrochemical
glycosyl
bromide
activations
via
halogen-atom
transfer
and
C-glycosylation.
The
radical
addition
to
alkenes
led
C-alkyl
glycoside
synthesis
under
precious
metal-free
reaction
conditions
from
readily
available
bromides.
robustness
of
our
e-XAT
strategy
was
further
mirrored
by
C-aryl
C-acyl
glycosides
assembly
through
nickela-electrocatalysis.
Our
approach
provides
orthogonal
with
expedient
scope,
hence
representing
a
general
method
direct
C-glycosides
assembly.
