ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
unknown, P. 17727 - 17738
Published: Nov. 18, 2024
We
demonstrate
an
efficient,
scalable,
and
stereoselective
C-glycosylation
with
thioglycosides
possessing
a
unique
photoactive
tetrafluoropyridin-4-yl
(TFPy)
thio
radical
leaving
group,
affording
editable
medicinally
biologically
essential
C-α-glucogallin
derivatives.
In
the
presence
of
silyl
enol
ether
acceptors,
desulfurative
coupling
reaction
performs
smoothly
under
mild
conditions
upon
exposure
to
blue
light
irradiation.
This
versatile
protocol
permits
synthesis
sugar-drug
chimeras
by
C1
ketonylation
complex
drug-derived
ethers.
The
scale-up
synthesis,
anomeric
epimerization,
post-C-glycosylation
modification
ketone
sugars
showcase
reaction's
potential
utilities.
Furthermore,
could
be
applied
direct
carbohydrate
skeleton
editing
equipping
group
on
nonanomeric
position.
is
viable
for
unprotected
TFPy
thioglycoside,
route
ketonyl
sugars.
concise
six-step
assembly
both
configurated
C-glucogallins
from
commercially
cheap
glucose
pentaacetate
their
antioxidant
reactivity
investigations
underline
promising
medicinal
relevance
our
current
protocols.
mechanism
was
investigated
through
trapping
experiment,
oxocarbenium
fluorescence
quenching
Stern–Volmer
analysis,
confirming
that
major
glycosyl
intermediates
are
generated
thioglycoside
donors,
whose
effectively
quench
excited
Ir(ppy)3
oxidative
process,
complementary
product,
accounting
examples
moderate
selectivities.
Green Chemistry,
Journal Year:
2022,
Volume and Issue:
24(5), P. 1995 - 1999
Published: Jan. 1, 2022
A
dehydrogenative
sulfonylation
of
tertiary
amines
with
thiosulfonates
under
visible-light
is
developed.
This
allows
for
the
construction
(a)cyclic
β-sulfonyl
enamines
transition-metal-free,
external
oxidant-free,
photocatalyst-free
and
mild
reaction
conditions.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(52)
Published: Aug. 29, 2024
Abstract
The
selective
functionalization
of
carbohydrates
holds
a
central
position
in
synthetic
carbohydrate
chemistry,
driving
the
ongoing
quest
for
ideal
approaches
to
manipulate
these
compounds.
In
this
study,
we
introduce
general
strategy
that
enables
regiodivergent
saccharides.
use
electron‐deficient
photoactive
4‐tetrafluoropyridinylthio
(SPyf)
fragment
as
an
adaptable
activating
group,
facilitated
efficient
across
all
saccharide
sites.
More
importantly,
group
can
be
directly
installed
at
C1,
C5
and
C6
positions
biomass‐derived
single
step
site‐selective
manner,
allowing
precision‐oriented
modification
unprotected
saccharides
glycans.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Sept. 19, 2024
The
synthesis
of
C1-ketonyl
glycosyl
compounds
featuring
α-selectivity
has
seldom
been
reported.
We
herein
devise
a
radical-based
approach
to
facilely
access
stereoenriched
ketonyl
via
an
Ir
photoredox-catalyzed
desulfurative
addition
silyl
enol
ethers,
using
in
situ-generated
tetrafluoropyridinyl
thioglycosides
from
1-thiols
as
radical
precursors.
This
protocol
features
readily
prepared
starting
materials,
mild
conditions,
excellent
functional
group
tolerance,
satisfactory
scale-up,
and
notable
amenability
late-stage
modification
pharmaceutically
relevant
complex
molecules.
ACS Catalysis,
Journal Year:
2024,
Volume and Issue:
unknown, P. 17727 - 17738
Published: Nov. 18, 2024
We
demonstrate
an
efficient,
scalable,
and
stereoselective
C-glycosylation
with
thioglycosides
possessing
a
unique
photoactive
tetrafluoropyridin-4-yl
(TFPy)
thio
radical
leaving
group,
affording
editable
medicinally
biologically
essential
C-α-glucogallin
derivatives.
In
the
presence
of
silyl
enol
ether
acceptors,
desulfurative
coupling
reaction
performs
smoothly
under
mild
conditions
upon
exposure
to
blue
light
irradiation.
This
versatile
protocol
permits
synthesis
sugar-drug
chimeras
by
C1
ketonylation
complex
drug-derived
ethers.
The
scale-up
synthesis,
anomeric
epimerization,
post-C-glycosylation
modification
ketone
sugars
showcase
reaction's
potential
utilities.
Furthermore,
could
be
applied
direct
carbohydrate
skeleton
editing
equipping
group
on
nonanomeric
position.
is
viable
for
unprotected
TFPy
thioglycoside,
route
ketonyl
sugars.
concise
six-step
assembly
both
configurated
C-glucogallins
from
commercially
cheap
glucose
pentaacetate
their
antioxidant
reactivity
investigations
underline
promising
medicinal
relevance
our
current
protocols.
mechanism
was
investigated
through
trapping
experiment,
oxocarbenium
fluorescence
quenching
Stern–Volmer
analysis,
confirming
that
major
glycosyl
intermediates
are
generated
thioglycoside
donors,
whose
effectively
quench
excited
Ir(ppy)3
oxidative
process,
complementary
product,
accounting
examples
moderate
selectivities.
