The Chemical Record,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 27, 2024
Carbohydrates
are
natural,
renewable,
chemical
compounds
that
play
crucial
roles
in
biological
systems.
Thus,
efficient
and
stereoselective
glycosylation
is
an
urgent
task
for
the
preparation
of
pure
structurally
well-defined
carbohydrates.
Photoredox
catalysis
has
emerged
as
a
powerful
tool
carbohydrate
chemistry,
providing
alternative
addressing
some
challenges
glycochemistry.
Over
last
few
decades,
Ir-
Ru-based
organometallic
photocatalysts
have
attracted
significant
interest
because
their
high
stability,
high-energy
triplet
state,
strong
visible-light
absorption,
long
luminescence
lifetime,
amenability
to
ligand
modification.
This
review
highlights
recent
progress
photocatalyst-promoted
synthesis
modification
carbohydrates
under
photoirradiation,
well
related
benefits
drawbacks.
Angewandte Chemie,
Год журнала:
2024,
Номер
136(36)
Опубликована: Июнь 5, 2024
Abstract
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
N
2
manner
to
give
desired
N‐glycosides.
An
alternative
route
involving
coupling
nitrogen‐centered
also
proposed,
affording
exclusive
1,2‐
trans
product.
This
novel
approach
promises
broaden
synthetic
landscape
N‐glycosides,
offering
powerful
tool
for
construction
complex
glycosidic
structures
mild
conditions.
Chemical Communications,
Год журнала:
2024,
Номер
60(66), С. 8684 - 8687
Опубликована: Янв. 1, 2024
Photochemical
multi-component
coupling
reactions
initiated
by
the
activation
of
glycosyl
bromides
in
presence
1,4-bis(diphenylamino)benzene
(BDB)
as
an
organic
photocatalyst
were
developed.
Research Square (Research Square),
Год журнала:
2024,
Номер
unknown
Опубликована: Июль 3, 2024
AbstractC-Glycosides
are
essential
for
the
study
of
biological
processes
and
development
carbohydrates-based
drugs.
Despite
tremendous
hurdles,
glycochemists
have
often
fantasized
efficient,
highly
stereoselective
synthesis
C-glycosides
with
shortest
steps
under
mild
conditions.
Herein,
we
report
a
desulfurative
radical
protocol
to
synthesize
C-alkyl
glycosides
coumarin
visible-light
induced
conditions
without
need
an
extra
photocatalyst,
in
which
stable
readily
available
glycosyl
thiols
that
could
be
obtained
intwo
or
three
from
native
sugars
activated
situ
by
pentafluoropyridine.
The
benefits
this
procedure
include
high
stereoselectivity,
broad
substrates
scope,
easily
handle.
Mechanistic
studies
indicated
produced
tetrafluoropyridyl
S-glycosides
formed
key
EDA
complexes
Hantzsch
ester
(for
C-alkyl
glycosides)
Et3N
coumarin
C-glycosides),
upon
irradiation
visible
light,
triggered
cascade
process
access
smoothly.
The Chemical Record,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 27, 2024
Carbohydrates
are
natural,
renewable,
chemical
compounds
that
play
crucial
roles
in
biological
systems.
Thus,
efficient
and
stereoselective
glycosylation
is
an
urgent
task
for
the
preparation
of
pure
structurally
well-defined
carbohydrates.
Photoredox
catalysis
has
emerged
as
a
powerful
tool
carbohydrate
chemistry,
providing
alternative
addressing
some
challenges
glycochemistry.
Over
last
few
decades,
Ir-
Ru-based
organometallic
photocatalysts
have
attracted
significant
interest
because
their
high
stability,
high-energy
triplet
state,
strong
visible-light
absorption,
long
luminescence
lifetime,
amenability
to
ligand
modification.
This
review
highlights
recent
progress
photocatalyst-promoted
synthesis
modification
carbohydrates
under
photoirradiation,
well
related
benefits
drawbacks.
