The Chemical Record,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 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.
Acta Pharmaceutica Sinica B,
Journal Year:
2023,
Volume and Issue:
14(3), P. 1030 - 1076
Published: Nov. 18, 2023
Synthetic
chemistry
plays
an
indispensable
role
in
drug
discovery,
contributing
to
hit
compounds
identification,
lead
optimization,
candidate
drugs
preparation,
and
so
on.
As
Nobel
Prize
laureate
James
Black
emphasized,
"the
most
fruitful
basis
for
the
discovery
of
a
new
is
start
with
old
drug"
Chem Catalysis,
Journal Year:
2024,
Volume and Issue:
4(3), P. 100891 - 100891
Published: Jan. 18, 2024
Harnessing
modern
catalytic
concepts
to
address
long-standing
challenges
in
carbohydrate
chemistry
has
garnered
substantial
interest
from
the
synthetic
community
recent
years.
In
particular,
usage
of
multiple
catalysts
for
sequential
one-pot
relay
reactions
already
contributed
major
benefits
accessing
oligosaccharides
past
two
decades.
contrast,
exploitation
synergistic
catalysis
glycosciences
is
only
its
infancy.
While
methods
combine
stepwise
into
a
single
flask
operation,
they
do
not
intrinsically
alter
reaction
mechanisms.
Conversely,
involves
creation
unique
mechanistic
pathways
by
merging
cycles.
At
nexus
cycles,
fertile
opportunities
arise
bond-forming
strategies
that
are
possible
within
individual
manifold.
The
realization
underexploited
potential
expected
accelerate
developments
field,
thereby
offering
stereoselective
entry
points
glycosidic
chemical
space
was
previously
inaccessible.
Nature Chemistry,
Journal Year:
2022,
Volume and Issue:
15(3), P. 424 - 435
Published: Dec. 30, 2022
Abstract
Site-selective
functionalization
is
a
core
synthetic
strategy
that
has
broad
implications
in
organic
synthesis.
Particularly,
exploiting
chiral
catalysis
to
control
site
selectivity
complex
carbohydrate
functionalizations
emerged
as
leading
method
unravel
unprecedented
routes
into
biologically
relevant
glycosides.
However,
robust
catalytic
systems
available
overcome
multiple
facets
of
stereoselectivity
challenges
this
end
still
remain
scarce.
Here
we
report
synergistic
Rh(I)-
and
organoboron-catalysed
protocol,
which
enables
access
synthetically
challenging
but
arylnaphthalene
Our
depicts
the
employment
Rh(I)
site-selective
showcases
utility
boronic
acid
compatible
co-catalyst.
Crucial
success
our
judicious
choice
suitable
organoboron
catalyst.
We
also
determine
exquisite
aspects
stereocontrol,
including
enantio-,
diastereo-,
regio-
anomeric
dynamic
kinetic
resolution,
are
concomitantly
operative.
The Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
88(9), P. 5713 - 5730
Published: April 20, 2023
The
use
of
quinuclidine
as
a
hydrogen
atom
transfer
(HAT)
mediator,
along
with
light-absorbing
photoredox
catalyst,
has
proved
to
be
powerful
and
general
approach
for
achieving
site-selective
radical
formation
from
carbohydrate
substrates.
Despite
numerous
literature
reports
documenting
the
scope
limitations
such
processes,
rationale
origins
site
selectivity
in
key
HAT
step
not
been
advanced.
In
this
study,
density
functional
theory
calculations
(M06-2X/def2-TZVP/PCM(acetonitrile))
were
used
model
transition
states
quinuclidinium
cation
pyranosides
furanosides
having
various
configurations
substitution
patterns.
data
set
(>120
state
geometries
energies)
allowed
detailed
examination
factors
that
influence
relative
rates,
augmented
by
additional
analysis
using
atoms
molecules
(AIM)
distortion/interaction-activation
strain
frameworks.
trends
have
emerged
regarding
effects
configuration,
conformation,
substitution,
noncovalent
interactions
are
consistent
experimental
observations
reveal
role
C-H···O
bonds
stabilizing
cation.
ACS Catalysis,
Journal Year:
2023,
Volume and Issue:
13(4), P. 2335 - 2340
Published: Jan. 31, 2023
Quinuclidine-mediated
electrochemical
oxidation
of
glycopyranosides
provides
C3-ketosaccharides
with
high
selectivity
and
good
yields.
The
method
is
a
versatile
alternative
to
Pd-catalyzed
or
photochemical
complementary
the
2,2,6,6-tetramethylpiperidine
1-oxyl
(TEMPO)-mediated
C6-selective
oxidation.
Contrary
methylene
methine
groups,
reaction
proceeds
without
oxygen.
Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(21)
Published: March 26, 2024
Abstract
Herein,
we
demonstrate
the
robustness
of
a
synergistic
chiral
Pd/organoboron
system
in
tackling
challenging
suite
site‐,
regio‐,
enantio‐
and
diastereoselectivity
issues
across
considerable
palette
biologically
relevant
carbohydrate
polyols,
when
prochiral
alkoxyallenes
were
employed
as
electrophiles.
In
view
burgeoning
role
noncovalent
interactions
(NCIs)
stereoselective
synthesis,
our
mechanistic
experiments
DFT
modeling
reaction
path
unexpectedly
revealed
that
NCIs
such
hydrogen
bonding
CH‐π
between
resting
states
Pd‐π‐allyl
complex
borinate
saccharide
are
critically
involved
stereoselectivity
control.
Our
strategy
thus
illuminates
untapped
potential
harnessing
context
transition
metal
catalysis
to
tackle
challenges
functionalization.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(21)
Published: March 26, 2024
Abstract
Herein,
we
demonstrate
the
robustness
of
a
synergistic
chiral
Pd/organoboron
system
in
tackling
challenging
suite
site‐,
regio‐,
enantio‐
and
diastereoselectivity
issues
across
considerable
palette
biologically
relevant
carbohydrate
polyols,
when
prochiral
alkoxyallenes
were
employed
as
electrophiles.
In
view
burgeoning
role
noncovalent
interactions
(NCIs)
stereoselective
synthesis,
our
mechanistic
experiments
DFT
modeling
reaction
path
unexpectedly
revealed
that
NCIs
such
hydrogen
bonding
CH‐π
between
resting
states
Pd‐π‐allyl
complex
borinate
saccharide
are
critically
involved
stereoselectivity
control.
Our
strategy
thus
illuminates
untapped
potential
harnessing
context
transition
metal
catalysis
to
tackle
challenges
functionalization.
